WO1994011855A1

WO1994011855A1 - Head mounted video display system with portable video interface unit

Info

Publication number: WO1994011855A1
Application number: PCT/US1993/009911
Authority: WO
Inventors: Gordon B. Kuenster; John W. Pace; Steven J. Shankle; Kevin W. Shimasaki; Fredrick W. Rivera
Original assignee: Virtual Vision, Inc.
Priority date: 1992-11-06
Filing date: 1993-10-15
Publication date: 1994-05-26
Also published as: AU5362694A

Abstract

A portable video display system (fig. 1) includes a head-up display unit (12) that includes optics for projecting an enlarged virtual image of video information depicted on a video display wherein the virtual image is viewable by a user wearing the head-up display unit. The video display system also includes a portable device (14) that may be carried on a user's clothing for receiving video signals and audio signals. The portable device (14) (fig. 3) couples the video signals to the video display of the head-up display unit and couples the audio signals to earphones. The portable device (14) includes a power supply (96) and, combines the audio, video and power signals so that they may be coupled to the video display unit (12) via a single lead (18). Further, in one embodiment, the portable device (14) includes a receiver for receiving radio frequency modulated video and audio signals that are coupled from the portable device (14) to the head-up display unit (12), wherein the portable device (14) may be mounted on a frame of the head-up display unit (12).

Description

HEAD MOUNTED VIDEO DISPLAY SYSTEM WITH PORTABLE VIDEO INTERFACE UNIT

This is a continuation-in-part of United States Patent Application Serial No. 07/973,155, filed November 6, 1992 and entitled "Portable Video Display System" (Docket No. 92 P 566) .

TECHNICAL FIELD

The present invention is directed to a portable video display system and more particularly to such a display system that includes a head mounted display unit for projecting an enlarged virtual image of video information in a user's field of view and a portable, modular video interface unit for receiving video signals from a television broadcast, a video recorder or monitor, a computer, etc. and for coupling the received video signals to the head mounted display unit. The portable interface unit also receives audio signals accompanying the video signals and couples the audio signals to earphones.

BACKGROUND OF THE INVENTION Known head mounted or head-up display systems are typically used for military applications. For example, a head-up display may be mounted on a helmet worn by a pilot in order to project an image in the pilot's direct line of sight and at infinity to aid the pilot in carrying out a military operation. Such systems typically include a cathode ray tube, CRT, that is mounted on the pilot's helmet where the CRT receives video information via heavy cables that are coupled to video display generating equipment that is fixedly mounted on the aircraft. Because these systems are cumbersome, , bulky and heavy, they are not suitable for consumer type applications.

SUMMARY OF THE INVENTION

In accordance with the present invention, the disadvantages of prior head-up display systems have been overcome. The display system of the present invention is a portable video display system that includes a compact and lightweight head mounted display unit for projecting an enlarged virtual image of video information in a user's field of view and a portable interface unit for receiving video signals from a television broadcast, a video recorder or monitor, a computer, etc. and for coupling the received video signals to the head mounted display unit for projection.

More particularly, the video display system of the present invention includes a head mounted display unit that has a video display for displaying video information, a frame to support the head mounted display unit on a user's head and optics for projecting an enlarged virtual image of the video information viewable by a user wearing the head mounted display unit. The video display system also includes a portable interface unit for receiving video signals representing a video image and for receiving audio signals representing sound to accompany the video image. The portable interface unit is coupled to the video display for providing the received video signals thereto. The portable interface unit is also coupled to at least one speaker or earphones that are responsive to the received audio signals to project the sound represented thereby.

In one embodiment of the present invention the portable interface unit includes a modulation circuit for combining received video signals with received audio signals to generate a composite signal that is coupled to the head mounted display unit via a single lightweight lead. The single lead can also be used for supplying power to the head mounted display unit. The head mounted display unit further includes a demodulator mounted on the frame for demodulating the composite signal to retrieve therefrom the video and audio signals which are respectively coupled to the video display and the audio speaker(s) .

The portable interface unit may include a number of inputs for receiving video signals from a number of different sources. One of the inputs may include a television broadcast tuner for receiving television, video and audio signals. The portable interface unit also includes a video selection input that is actuable by a user to couple one of the plurality of inputs to an output of the portable interface unit. A second input of the portable interface unit may be an input from a video recorder or monitor that may be any device that generates video signals.

The portable interface unit may be coupled to the video source such as a video recorder or monitor via a cable or the like. Alternatively, the video source may include a radio frequency modulator for modulating the video and if present, audio signals of the video source. The video recorder/monitor further includes a transmitter for transmitting the radio frequency modulated video and audio signals. The portable interface unit in this embodiment includes a receiver for receiving , the radio frequency modulated signals and a demodulator that is coupled to the receiver for demodulating the receive signal to provide a video signal representing the video information and to provide audio signals if present. The demodulated video information is coupled from the portable interface unit to the video display of the head mounted display unit so that an enlarged virtual image of the video information is projected in the user's field of view while the demodulated audio signals are coupled to a speaker(s) or earphone(s) .

In a preferred embodiment, the head mounted display unit includes a very small thin film transistor (TFT) , color LCD panel that is extremely small in size. This LCD panel is driven by a chroma-sync I.e. and a LCD driver to control the LCD display to depict the video information coupled thereto from the portable device. Because the LCD display is very small, the display may be mounted on the frame with respect to a mirror also mounted on the frame but in the periphery of the user's field of view where the mirror receives the displayed video information directly from the LCD panel. The mirror may be fully reflective or partially reflective and further collimates light to project an enlarged image of the video information at a distance from the user. Preferably, the distance at which the image is projected by the mirror is less than infinity.

These and other objects, advantages and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and the drawing.

BRIEF DESCRIPTION OF THE DRAWING Fig. l is a perspective view of one embodiment of the portable video display system of the present invention;

Fig. 2 is a block diagram illustrating the electronics mounted on the frame of the head mounted display unit in accordance with an embodiment of the present invention; Fig. 3 is a block diagram illustrating an embodiment of the portable interface unit of the video display system depicted in Fig. 1;

Fig. 4 is a block diagram of a receiver that may be included in the portable interface unit depicted in Fig. 3 or the head mounted display unit;

Fig. 5 is a block diagram of a video and audio modulator and transmitter for a video monitor/recorder such as depicted in Fig. 1;

Fig. 6 is a block diagram of a video monitoring system in accordance with one embodiment of the present invention;

Fig. 7 is a front view of one embodiment of a head mounted display unit in accordance with the present invention illustrating the video display and optics used therein;

Fig. 8 is a side view of the head mounted display unit depicted in Fig. 7;

Fig. 9 is a back view of the head mounted display unit depicted in Fig. 7: Fig. 10 is an illustration of the CRT and optics utilized in the head mounted display unit depicted in Fig. 7;

Figs. 11A-B illustrate an inter-ocular adjustment mechanism for a head mounted display unit;

Figs. 12A-B illustrate a focal length adjustment mechanism for the head mounted display unit depicted in Fig. 7; Fig. 13 is a perspective view of another embodiment of a suitable head mounted display unit in accordance with the present invention;

Fig. 14 is a back perspective view of the head mounted display unit depicted in Fig. 13; Fig. 15 is a front perspective view illustrating still another embodiment of a head mounted display unit in accordance with the present invention;

Fig. 16 is block diagram illustrating another embodiment of the portable interface unit depicted in Fig. 1;

Fig. 17 is a block diagram illustrating another embodiment of the electronics incorporated into the head mounted display unit for a video display system utilizing the portable interface unit depicted in

Fig. 16;

Fig. 18 is a perspective view of a modular portable interface unit having a video module in the form of a television tuner mounted thereon; Fig. 19 is a back view of the portable interface unit depicted in Fig. 18;

Fig. 20 is a top perspective view of the top housing of a first section of the portable interface unit for mounting a video display module; Fig. 21 is a perspective view of the bottom housing of the first housing section of the portable interface unit and a perspective view of the hinge connecting the first housing section and the second housing section of the portable interface unit; Fig. 22 is a top perspective view of a top housing of the second housing section of the portable interface unit for mounting a power supply module;

Fig. 23 is a bottom perspective view of a bottom housing of the second housing section of the portable interface unit;

Fig. 24 is a bottom perspective view of the bottom housing for a video module in the form of a television tuner; Fig. 25 is a top perspective view of a top cover of a video module in the form of a television tuner and of an antenna therefor;

Fig. 26 is a perspective view of the portable interface unit with a power supply module and television tuner mounted thereon, the interface unit being shown in its open or extended position;

Fig. 27 is a perspective view of the portable interface unit depicted in Fig. 26 in the closed position; Fig. 28 is a perspective view of the portable interface unit depicted in Fig. 26 with the antenna extended;

Figs. 29A-E is a block diagram illustrating the circuitry of the modular portable interface unit; and

Fig. 30 is a block diagram of a modular transmitter module in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT One embodiment of the video display system 10 of the present invention, as shown in Fig. 1, includes a head mounted display unit 12 and a portable interface unit 14. The portable interface unit 14 receives video signals and, if available, audio signals respectively representing video images and accompanying sound for transmission via a cable 18 to the head mounted display unit 12. The portable interface unit 14 may receive TV broadcast signals, video signals from a computer, video and audio signals from a video monitor such as a video camera or other device that can provide video signals or from a video recorder such as a hand-held camcorder 20, etc. The video monitor 20 may couple video and/or audio signals directly to the portable interface unit 14 via a cable connection (not shown) . Alternatively, the video monitor 20 may include a modulator/transmitter 22, described in detail below, that may be mounted on the video monitor 20 by a connection to the tripod mount of the monitor. The modulator/transmitter 22 receives the video and audio signals from the video monitor 20 and radio frequency modulates these signals. The modulated signals are transmitted via a stub antenna 24 or the like to the portable device 14 which is modified to include a receiver/demodulator, as described below. This configuration of the video display" system 10 allows a user to view what the video monitor 20 is picking up from a location remote from the monitor 20. This configuration also allows a user to watch a video tape or other video source, while within range of the transmitter unit 22. The portable device 14 also includes a source selector switch 26 to couple the video and/or audio inputs received by the unit 14 from a selected one of a number of sources such as a TV broadcast tuner, video monitor, computer, etc. to the output of the unit 14. The portable device 14 includes a band selection switch or TV channel selector 28, as well as a volume control knob 30. It is noted that the portable interface unit 14 is compact and lightweight such that it may be attached to the user's clothing, such as a belt, or it may be carried on a strap, the portable interface unit 14 in these instances being separate or remote from the unit 12.

The head mounted display unit 12 includes a frame 16 to support the unit 12 on a user's head. The head mounted display unit 12 may be as shown in United States Patent Application Serial Number 07/345,886 filed May 1, 1989, now issued U.S. Patent Number 5,162,828, which is incorporated herein by reference. As described below, in a preferred embodiment, the head mounted display unit 12 includes a video display such as an LCD or a CRT that is mounted on the frame 16. The video display receives the video signals from the portable device 12 to depict the video information represented by those video signals. A mirror, which may be totally reflective or partially reflective, is disposed in the user's peripheral field of view and is positioned with respect to the video display of the unit 12 so as to collimate light to project a virtual image of the displayed video information at a distance from the user in the periphery of the user's field of view. Preferably, the mirror is toroidal, or includes a Vernike polynomial surface to project an enlarged virtual image of the displayed information. Further, although the mirror may be such as to focus the image at infinity, in a preferred embodiment, the mirror focuses the image at a distance that is less than infinity and at a normal viewing distance from the user for the type of video information being displayed. For example, if the head mounted display unit 12 is utilized to depict computer information, such that the unit 12 forms a computer display, the viewing mirror focuses the image at a distance that may be relatively close to the user. Alternatively, when the head mounted display unit 12 is used to display the image picked up by a video monitor 20, the mirror might focus the image at a distance that appears to be farther from the user. It is noted that head mounted display units of various other configurations may be utilized with the portable interface unit of the present invention. For example, the head mounted display system may be stereoscopic utilizing a display and optics for both eyes. Further, the mirror colli ating optics need not be positioned in the user's field of view. The audio signals received by the portable interface unit 14 are further coupled by the cable 18 to the head mounted display unit 12 for coupling the audio signals to one or more speakers 32, or earphones, so that the user can listen to any sound accompanying the received video image viewed by the user through the head mounted display unit 12. It is noted that the portable interface unit 14 also preferably includes the power supply for the entire video display system 10 as well, power being coupled to the head mounted display unit 12 via the cable 18.

The video display system 10, when utilized with a video monitor, allows the user to control unusual camera angles and provides the user with the ability to view around corners or over the heads of a crowd since the user is not restricted to viewing the image picked up by the video monitor through the video monitor's view finder. Further, because of the compact nature of the video display system 10, a user may view a TV broadcast or the output from a computer in situations heretofore not possible due to the bulk, size, and weight of conventional television monitors and computer monitors.

The electronics for one embodiment of a head mounted display unit 12 utilizing a CRT is depicted in Fig. 2, wherein the electronics shown therein are mounted on the frame 16 of the unit 12. More particularly, as shown in Fig. 2, the head mounted display unit 12 receives a composite video signal, +5 volts, a ground connection, right audio and left audio signals via multiple leads contained in the cable 18, the leads being connected to the unit 12 via a nine-pin connector 40, or the like. The right and left audio signals are coupled via the connector 40 to respective right and left earphones 42 and 43. The composite video signal input to the connector 40 includes horizonal and vertical sync signals, as well as video pixel information. This composite video signal is coupled to a sync stripper 44 through an amplifier 46. The sync stripper 44 may be a Matsushita AN 2512S device which utilizes the horizontal and vertical sync pulses from the input composite video signal to respectively control the horizontal and vertical deflection drives 48 and 50 of the CRT 52 to position the CRT beam. The sync stripper 44 also couples the video pixel information from the composite video input signal to the CRT 52 via a grid drive 54 of the CRT, wherein the grid drive includes a brightness control 56. Focusing of the CRT beam is controlled by a focus control 58 coupled to the CRT through a flyback transformer 60.

One embodiment of the portable interface unit

14 is depicted in Fig. 3. As shown therein, the portable interface unit 14 includes a TV broadcast tuner 70 which may take the form of a Casio TR30-2A television tuner, or the like, that is coupled to an antenna 72 for picking up UHF or VHF television broadcasts. The broadcast tuner 70 is responsive to the band or channel select switch 28 to pick up a user-selected TV broadcast. The video signals from the broadcast tuner 70 are coupled via a line 72 to a video drive amplifier 74 to provide the composite video signal to an output connection 76 of the portable interface unit 14. Similarly, the respective right and left audio signals are coupled via respective lines 78 and 80 through the source select switch 26 to respective audio amplifiers 82 and 84, each of which is coupled to the volume control knob 30. The outputs of the audio amplifiers 82 and 84 are coupled to the output connector 76 of the portable interface unit 14. The portable interface unit 14 also includes a video input port 90 and respective right channel and left channel audio input ports 92 and 94 which may be coupled via a cable to the respective video and audio outputs of a video monitor 20. Alternatively, the video input port 90 may be used to couple video inputs "from a computer to the portable interface unit 14. The input ports 90, 92, and 94 are coupled to the respective drive amplifiers 74, 82, and 84 via the source select switch 26 when the switch is in the appropriate position. To minimize the size and weight of the head mounted display unit 12, the portable interface unit 14 includes a battery pack and power supply 96 for powering the components of the portable device 14 as well as the electrical components mounted on the frame 16 of the head mounted display unit 12. The power and ground connections are coupled to the head mounted display unit through the output connector 76. The portable interface unit 14 may be modified to include the circuitry depicted in Fig. 4 in addition to that depicted in Fig. 3 so as to allow auxiliary video and audio inputs that are radio frequency modulated to be picked up via a stub antenna 25 or the like. More particularly, the receiver 100 receives an RF modulated signal via the antenna 25 which is coupled to a radio frequency selective amplifier 102 tuned to approximately 900 Mhz. The output of the amplifier 102 is coupled to a phase locked loop demodulator 104, the other input of which is a 900 Mhz signal from a tunable oscillator 106. The phase locked loop demodulator 104 removes the carrier signal from the received modulated signal, the output from the demodulator 104 being coupled to a 3.7 Mhz low-pass filter 108. The low-pass filter 108 filters the signal input thereto to provide at the output of the filter a signal representing only the video information. The video signal output from the low-pass filter 108 is applied to the video drive amplifier 74 through the selector switch 26 in the event that multiple input sources" are utilized. The output of the phase locked loop demodulator 104 is also coupled to an additional pair of phase locked loop demodulators 110 and 112. The phase locked loop demodulator 110 is coupled to a 4 Mhz signal which is the frequency of modulation of the left audio signal output from an oscillator 114 so as to demodulate the signal. The left audio signal output from the demodulator 110 is coupled to the left audio drive amplifier 84 via the selector switch 26, if utilized. Similarly, the phase locked loop demodulator 112 receives an input from a 4.5 Mhz oscillator 116 so as to demodulate the signal input from the demodulator 104 to provide a right audio signal. The right audio signal output from the phase locked loop demodulator 112 is coupled via the selector switch 26, if used, to the drive amplifier 82. It is noted that the receiver 100 may be utilized to pick up radio frequency modulated outputs from a video monitor or a computer monitor which includes the modulator/transmitter 22. The receiver 100 may also be utilized to pick up radio frequency modulated outputs from a TV tuner where the TV tuner may, for example, be located remotely from the portable interface unit 14 and modified to include a modulator/transmitter 22. It is further noted that the portable interface unit 14, including the receiver 100, may be mounted on the frame 16 of the head mounted display unit 12 so as to receive video and/or audio information from a remote source such as a remote TV tuner, remote video monitor, remote computer, or the like. The modulator/transmitter 22 as depicted in Fig. 5 may be coupled to the video and right and left audio outputs of a video monitor or recorder or such outputs from a TV tuner for transmission to the portable interface unit 14, which as described above, may be separate from the head mounted display unit 12 or an integral part thereof. The video signal input to the transmitter 22 is applied to an amplifier 120 having a constant level of output which is applied to a 3.7 Mhz low-pass filter 122. The left audio signal applied to the transmitter 22 is coupled to an amplifier 124, the output of which is applied to a first input of a phase locked loop modulator 126. The second input of the phase locked loop modulator 126 is coupled to the output of a 4 Mhz oscillator 128 so as to modulate the left audio signal with the 4 Mhz signal. Similarly, the right audio signal applied to the transmitter 22 is coupled to an amplifier 130, the output of which is applied to a first input of a phase locked loop modulator 132. The second input of the phase locked loop modulator 132 is coupled to the output of a 4.5 Mhz oscillator 134 to modulate the right audio signal with the 4.5 Mhz signal. The video signal output from the low-pass filter 122 is modulated by a 900 Mhz carrier signal coupled to a phase locked loop modulator 136 from an oscillator 138. The output of the modulator 136 is applied to summing junctions 140 and 142 which respectively add the 4 Mhz modulated left audio signal and the 4.5 Mhz modulated right audio signal thereto to combine the audio signals with the carrier modulated video signal. The combined audio and video RF modulated signal is applied to a side lobe cancelling bandpass filter 144 prior to final amplification by a radio frequency amplifier 146 for transmission to a remote receiver 100 via an antenna 150. The transmitter 22 may also include a power supply 152 coupled to batteries 156 and to an on-off switch 154.

In an embodiment of the present invention depicted in Fig. 6, the transmitter module 22 is coupled to a number of video monitors 160-163 through a time controlled cross point switch 166 such as a multiplexer. In this application, the time control cross point switch multiplexes the video, and audio outputs if present, of each of the monitors 160-163 in a sequential manner to the transmitter module 22. The transmitter module in turn transmits the received video and, if present audio signals, to the video display system 10 so that a user can monitor the outputs from multiple video sources. This system allows a guard, for example, to view the scenes picked up by multiple video monitoring cameras while the guard walks around inspecting the premises. This system also allows an engineer or process control operator to monitor various processes or the outputs of various machines while walking around in a factory or other large area. It is further noted that a single video monitor having a modulator/transmitter 22 may transmit video and audio signals to a number of users each user having his own head mounted display unit 12 and receiver 100. Such a video display system may be utilized for self-guided tours, station specific training or the like. One embodiment of the head mounted display unit 12 in accordance with the present invention is depicted in Figs. 7-10. As shown therein, the head mounted display unit 170 includes a frame 171 for supporting a pair of viewing transparencies 173 and 175 which may be such as the lenses of a conventional pair of glasses. The frame 171 includes an extension portion 177 that is positioned above the transparencies 173 and 175. The extension 177 houses a CRT display 172, the deflection coils 176 for the CRT and the electrical components for driving the CRT such components being depicted in Fig. 2. It is also noted that the frame extension 177 may also house the receiver depicted in Fig. 4 in accordance with one embodiment of the present invention. The video information depicted on the CRT display 172 is projected onto an optical system so that an enlarged virtual image of the video information may be viewed by the wearer of the unit 170. More particularly, a flattening lens 182 couples the video information projected from the CRT 172 onto a 90° prism 180. The prism 180 receives an image of the displayed computer information along a first axis corresponding to the longitudinal axis of the CRT, the prism 180 projecting the received image along an axis that is perpendicular to the CRT axis so that the video image is projected onto a lens 184. The lens 184 is an adjustable focusing lens so as to allow a user to adjust the focal length thereof by moving the lens up and down, i.e. in a direction perpendicular to the axis of the CRT 172. The focusing lens projects the video information from the CRT 172 onto a mirror 186 that is mounted on either a portion of the frame 171 or on a transparency 175 as shown in Fig. 7. More particularly, as shown in Fig. 7, the mirror 186 is mounted on a bracket 190 which may be removable attached to the transparency 175. The bracket 190 supports the mirror 186 for rotation about an axis 192 so that the user may adjust the path between the lens 184, the mirror 186 and the user's eye. The mirror 186 may be reflective, or partially reflective and forms a viewing mirror wherein^* the user views the video information from the CRT 172 through the mirror 186. The mirror 186 collimates light to project a virtual image of the displayed information at a distance from the user wherein the distance may be at infinity or less than infinity. As seen in Fig. 7, the mirror 186 is disposed on the lens 175 such that the mirror is in the user's peripheral field of view. This positioning of the mirror allows the user to view the projected image while still being able to view his surroundings. This allows the user to be cognizant of his surroundings while viewing the video information projected by the head mounted display unit 170. As shown in Fig. 9, the frame 171 may include a nose piece 195 to contribute to the support of the head mounted display unit 170 on the user's head. Further in an alternative embodiment of the invention, the mirror 186 is mounted on an extension 197 of the nose piece 195.

An earpiece boom extends from the frame 171 of the head mounted display unit 170 so that the audio signals received by the electronics 178 may be coupled to the boom 194 via leads contained within the frame 171 for example. A volume adjustment 198 is also mounted on the frame 171 so that the user can easily adjust the volume of the sound projected from the speaker 196. In order to make inter-ocular adjustments, a mechanism 200 shown in Figs. llA-B may be disposed between two halves of the head mounted display unit 170 wherein one half of the unit 170 is associated with the transparency 173 and the other half is associated with the transparency 175. The mechanism 200 as shown in detail in Fig. IIB includes a rotatable nut 200 which when rotated, forces the two halves of the unit 170 apart so as to adjust the plane defined by the center of the mirror 186 mounted on the transparency 185, the center of the lens 184 projecting the video information onto the mirror 186, and the user's eye. A device for adjusting the position of the focusing lens 184 is also depicted in Figs. 12A and 12B. As shown therein, the focal length adjustment mechanism 204 forms a carrier for the lens 184 and includes a track 206 which engages a cooperating member, not shown, that is disposed on the frame 171. As the lens carrier 204 is rotated about an axis perpendicular to the plane of the lens, the lens 184 is caused to move in an upward or downward direction, parallel to the axis of rotation.

An alternative embodiment of the head mounted display unit 12 in accordance with the present invention is depicted in Fig. 13. As shown in Fig. 13, the head mounted display unit 220 includes a frame 222 that supports a housing 224 in which is disposed the video display and the video display drive electronics. The frame 222 includes a downwardly extending member 226 having a mirror support member 228 projecting from an end thereof. The member 228 supports a mirror 230 for movement thereof so that the optical path between the video display, the mirror 230 and the user's eye may be adjusted. Although the housing 220 may contain a CRT display and associated optics as discussed above with respect to Figs. 7-10, in a preferred embodiment, the housing 220 supports a thin profile display mounted as shown in Fig. 14 on a bottom surface 234 of the housing 220. The display 236 may for example take the form of a liquid crystal display and in particular a thin film transistor color LCD panel as depicted in Fig. 17. Such displays are extremely small but provide very high resolution for displaying video information. For example, a known thin film transistor color LCD is available from Seiko Epson which has a display screen size of approximately llmm by 14.4mm for depicting 244 by 428 pixels. With such a display 236, the mirror 23.0 may receive the video information depicted on the display 236 directly therefrom such that no optics such as the 90° prism are needed to be disposed between the display and the mirror. It is noted, that the LCD display 236 may include a lens such as a Schmidt corrector if desired. Because there are no intervening optics disposed between the mirror 230 and the display 236, the profile of the housing 220 of the head mounted display unit is reduced from even that depicted in Fig. 13 to provide a very sleek low profile display unit 12.

A further embodiment of the head mounted display unit of the present invention is depicted in Fig. 15. As shown therein, a head mounted display unit in accordance with this embodiment includes a frame.300 that extends from one side of the user's head over the top of the head to the other side thereof. A first bracket 302 extends from the frame 300 and includes at an end 304 thereof the display wherein an LCD display 236 or the like is mounted on a bottom surface 306 of the projection 304. A second bracket 310 also extends from the frame 300 wherein a mirror support 312 is rotatably mounted via a connector 314 to an outer end of the bracket 310. The viewing mirror 315 is mounted on the support 312 so as to be vertically aligned with the display 306. The mirror support 312 is rotatable so as to allow the optical path defined by the display, the mirror 315 and the user's eye to be adjusted to accommodate various users. Further, one or both of the brackets 302 and 310 may be movably secured to the frame 300 by a member 320 that allows one or both of the brackets to rotate about an axis extending through the member 320. This feature allows the distance between the display and the mirror 315 to be adjusted as desired.

The portable device 14 as depicted in Fig. 3 et seq. may be modified in accordance with the block diagram depicted in Fig. 16. More particularly, as shown in Fig. 16, the video and audio signals are combined with a DC level from the power supply so that one lead contained within the cable 18 can carry the video and audio information as well as power to the head mounted display unit 12. This feature substantially reduces the size and weight of the cable 18. The left audio signal to be transmitted to the head mounted display unit 12, output from the amplifier 84 is input to a phase locked loop FM modulator 400 which also receives a 4Mhz modulating signal from an oscillator 402. Similarly, the right audio signal output from the amplifier 82 is applied to the input of a phase locked loop FM modulator 406 which also receives as an input a 4.5Mhz modulating signal from an oscillator 404. The modulated left audio and right audio signals output from the respective modulators 400 and 406 are combined at a summing junction 410 with the video signals output from the amplifier 74. The output from the summing junction 410 is applied to a phase locked loop FM modulator 412 to which is also applied a 70Mhz carrier signal from an oscillator 412. The composite video and audio, FM modulated signal output from the phase locked loop modulator 412 is applied to a buffer amplifier 416. The output of the amplifier 416 is AC coupled, as represented by the capacitor 418, to a lead 420 to which a DC power signal from the power supply 96 is also applied. The single lead 420 thus carries the video information, audio information and power needed for the head mounted display unit 12 which is modified to receive this composite signal as shown in Fig. 17.

As shown in Fig. 17, the composite signal carried on line 420 is AC coupled, as illustrated by the capacitor 430, to the electronics mounted on the frame 16 of the head mounted display unit 12. The AC coupled signal is applied to a quadrature detector 432 to which is also applied a 70Mhz signal from an oscillator 434. The quadrature detector 432 removes the 70Mhz carrier signal from the composite signal applied thereto. The output of the quadrature detector 432 is coupled to a phase locked loop FM demodulator 438 through a 25Khz bandpass filter 436 that operates at 4Mhz. A 4Mhz signal is applied from an oscillator 440 to the demodulator 438 to demodulate the left audio signal, the demodulated signal being applied to a buffer amplifier 441 coupled to the left speaker or earphone. Similarly, the output of the quadrature detector 432 is coupled to a phase locked loop FM demodulator 444 through a 25Khz bandpass filter 442 operating at 4.5Mhz. A 4.5Mhz signal from an oscillator 446 is also applied to the demodulator 444 so as to demodulate the right audio signal. The demodulated right audio signal is then applied to the right earphone or speaker via a right buffer amplifier 448. The output of the quadrature detector 432 is applied to a chroma-sync I.e. 450 to retrieve the video signal therefrom. The chroma- sync I.e. 450 provides RGB signals that are coupled to a thin film transistor color LCD 236 that is also coupled to the I.e. 450 through an LCD driver 452. The composite signal received on line 420 is applied to a power regulator 460 which retrieves the DC power signal therefrom to power the electronics contained on the head mounted display unit 12. The power signal is also coupled to a back light power supply 462 having a brightness control input 464 the output of which controls a back light 466 for the color LCD 236. The portable interface unit 14 is preferably modular as shown in Figs. 18-29. As shown in Fig. 18, the portable interface unit includes a housing generally designated 500 having a video module mounting surface or top 502 for mounting a video module such as a television tuner module 504. The housing 500 also includes a power supply module mounting surface or top 506 for mounting a power supply module 508. As described below, the power supply module 508 may be a conventional battery pack for a video camera such as a camcorder or the power supply may be an interface to an electrical wall outlet so as to eliminate the need for a battery.

The housing 500 is formed of two sections 511 and 513. The first housing section 511 includes the top 502 with the video module mounting surface and a back housing 512. The second housing section 513 includes the top 506 with the power supply module mounting surface and a back housing 514. The first and second sections 511 and 513 are coupled together by a hinge 510 that allows the interface unit 14 to be opened into an extended position as shown in Figs. 18-, 19, 26 and 28 or closed as shown in Fig. 27. In the closed position the back walls 516 and 518 of the respective back housings 512 and 514 abut with a protrusion 520 on the back wall 516 being inserted into a recess 322 formed in the back wall 518 so as to snap the two housing sections 511 and 513 together. It is noted that the protrusion 520 may be formed as a hook so as to enable the portable interface unit 14 to be attached to a user's belt or the like.

The top 502 of the first housing section 511 has a generally flat upper surface 524 with a recess 526, 528 formed in opposite ends thereof. A pair of hooks 530, 532 and 534, 536 are formed in the respective recesses 526 and 528 with an opening 538, 540 disposed between the hooks of a given pair. This upper surface with the recesses 526, 524, hooks 530, 532, 534 and 536 and openings 538, 540 forms the mounting surface for any one of a number of video modules such as the T.V. tuner 504. Further, this mounting surface has essentially the same configuration or footprint as a conventional video camera battery pack such as a Sony camcorder battery pack in order to allow the housing 500 to be mounted on such a video camera wherein the upper surface 524 engages the battery pack mounting surface of the camcorder. The top 502 of the first housing section 511 also includes an aperture 542 for a multi-pin connector so as to couple video and audio signals from the video module mounted thereon to the interface circuitry contained within the first housing section 511 as discussed in detail below. Power is also coupled from the interface circuitry to the video module via the connector 541. A pair of apertures 544 and 546 are disposed in the upper surface 524 of the top 502 in order to match the footprint of a conventional video camera battery pack mounting surface. Further, a recess 548 is formed in the upper surface 524 so as to engage a flexible locking hook or member 560 formed on the bottom surface 562 of the bottom housing 564 of each video module that is connectable with the portable interface unit so as to lock the video module in place therein. A slot 550 and a pair of apertures 551 and 552 are disposed on the side wall 554 of the top housing 502 so as to accommodate a volume control slide member, an on-off switch and an output jack 555 that couples video, audio, power and various control information from the portable interface unit 14 to the head mounted display unit 12.

The back housing 512 of the first housing section 511 is formed with a generally rectangular recess 570 in one side wall thereof so as to accommodate the hinge 510. A pair of pins 572 and 574 are mounted on respective end walls 571 and 573 of the recess 570 such that the pins extend into the recess 570 with the longitudinal access of the pins extending parallel to the longitudinal access of the recess. The hinge 510 includes a pair of housing sections 580 and 582 with semi-circular apertures 584 and 586 disposed in each end wall of the hinge sections 580 and 582 so that when the hinge sections are snapped together, the apertures 584 in the housing section 580 align with the apertures 586 in the hinge section 582 forming circular apertures. The pins 572 and 574 of the back housing 512 of the first housing section 511 extend into one pair of apertures formed on the hinge 510 whereas corresponding pins formed in a recess of the back housing ■ 514 extend through another pair of hinge apertures so as to allow the first and second housing sections 511 and 513 to pivot with respect to the hinge 510 thereby allowing the housing to be opened into its extended position or to be snapped closed. The back housing 512 also includes a slot 576 in a sidewall 579 so as to accommodate a second volume control slide member. It is noted that the first volume control slide member may control the volume for a right earphone whereas the second volume control slide member may control the volume for a left earphone. The top 506 of the second housing section 513 as shown in Fig. 22 mounts a power supply module 508. The power supply module 508 may be a conventional battery pack for a video camera as discussed above. Alternatively, the power supply module may include an interface for A.C. power with a cord and plug for an electrical wall outlet. The mounting surface 590 for the power supply module 508 has essentially the same configuration as the battery pack mounting surface for a video camera such as a Sony camcorder. More particularly, the mounting surface 590 includes a pair of outwardly extending end walls 592 and 594, each end wall having a pair of hooks 595, 596 and 597, 598 formed adjacent thereto so as to engage respective hooks formed in respective recesses in the end walls of the upper surface of the power supply module 508. The mounting surface 590 also includes a flexible hooking member 600 that is formed with a flange 602 and an outwardly extending protrusion or hook 604. The protrusion 604 snaps into a recess that is formed on the power supply module so as to lock the power supply module 508 in place on the second housing- section 513. An aperture 606 is formed in the upper surface 590 of the top 506 so as to accommodate an electrical connector 599 to couple power from the power supply module 508 to the interface circuitry contained in the second housing section 513.

The back housing 514 of the second housing section 513 is shown in Fig. 23 and is similar to the back housing 512 of the first housing section 511 in that it includes a recess 610 formed in a side wall thereof with pins 612 and 614 extending outwardly from respective end walls 616 and 618 of the recess so as to engage respective apertures formed in the end walls of the hinge 510. Each of the back housings 512 and 514 of the first and second housing sections 511 and 513 also includes a longitudinally extending slot 620 formed therein. The longitudinally extending slots 620 formed in the back housings 512 and 514 are aligned with respective longitudinal slots 622 and 624 that are formed in the side walls of the hinge 510 when the housing sections 511 and 513 are mounted to the hinge 510. The slots 620, 622 and 624 allow an electrical ribbon connector 625 to extend from the first housing section 511 through the hinge 510 to the second housing section 513 so as to enable the interface circuitry contained in each of the housing sections 511 and 513 to be connected.

The top 630 and bottom 564 housing sections of the video module 504 in the form or a television tuner are depicted in Figs. 24 and 25. The top 504 of the television tuner video module includes a recess 632 formed along one side thereof wherein the recess 632 provides a storage area for an antenna body 634 when the antenna is in its retracted position. An aperture 638 is formed in one end of the recess 632 so as to receive an antenna mounting member 636 therein. The antenna mounting member 636 pivotally mounts the antenna body 634 so that the antenna body 634 may be rotated or pivoted out of the recess 632 and the antenna contained in the body 634 extended. The top 630 of the T.V. tuner video module 504 also includes a pair of apertures 640 therein so as to accommodate channel select knobs, for example a digital up channel control knob and a down channel control knob.

The bottom 564 of the television tuner video module housing 504 has an outer mounting surface 562 that is configured to mate with an mount on the surface 524 of the top 502 of the first housing section 511. More particularly, the outer surface 562 of the bottom 564 of the video module 504 includes a pair of end walls 654 and 656 with a pair of hooks 652 formed adjacent each end wall and a rib 660 formed adjacent each end wall between the hooks. The hooks 652 engage respective hooks 530, 532, 534 and 536 formed on the mounting surface 524 of the top 502 of the first housing section with the rib 660 extending into a respective recess 538, 540. The outer surface 562 of the bottom video module housing section 564 also includes a flexible hooking member 560 with a flange 670 and an outwardly extending protrusion or hook 672 formed in an end thereof. The hook or protrusion 672 is received into the recess 548 of the top 502 when the video module 504 is mounted on the first housing section 511 so as to lock the video module 504 thereon. It is noted that the housing 500 need not be hinged. The housing sections 571 and 573 may be joined to form a single housing for the interface circuitry with the mounting surfaces for the video module and power supply module adjacent to each other or on opposite sides of the housing such as when the housing 500 is in the closed position. The adjacent mounting. surfaces might be preferable when the unit is carried by a user because the unit's profile is sleeker. However, when the unit is mounted on a video camera, the mounting surfaces for the power supply module and the video module are preferred to be on opposite sides of the unit. Although the hinge 510 makes the unit flexible so that it can easily be used in either mounting surface configuration, a hinged housing is not necessary to practice the present invention.

Fig. 29A illustrates the circuitry for the modular, portable interface unit 14 that is contained in the housing sections 511 and 513. The interface circuitry contained within the housing 500 is divided into a first section contained within the housing section 511 and a second section contained within the housing section 513. The interface circuitry contained within the housing section 513 includes a power supply module connector 599 that includes negative and positive battery input connections 710 and 712 as well as an external power jack 716. The negative and positive battery input connections 710 and 712 connect to respective positive and negative output terminals of a battery pack module 508. The external power jack 716 of the power supply module connector 599 is connectable to a battery eliminator power supply module that includes either an A.C. adapter that can be coupled to an electrical wall outlet or a D.C. adapter. Power from the power supply module is coupled through the connector 599 to a switcher power supply 714 that provides power to a modulator 720 as well as a microprocessor controller 722 contained within the housing section 511 of the portable interface unit. The D.C. voltage from the power supply module is also coupled via leads 723 and 725 through the ribbon connector 625 contained within the hinge 510 to leads 727 and 729 that are respectively coupled to positive and negative battery output connections 724 and 726 that form a portion of the connector 541 disposed on the housing section 511. The battery output connections 724 and 726 connect to battery input connections 730, 732 disposed on the respective video modules 740, 742 and 744 as shown in Figs. 29B, C and D so as to provide battery power from the power supply module 508 to the respective video module 740, 742 and 744.

The interface circuitry contained within the housing section 513 also includes three auxiliary input jacks which are phono switch jacks 746, 747 and 748. The jack 746 is to provide audio for a right earphone, i.e. right audio whereas the auxiliary input jack 747 provides audio for a left earphone, i.e. left audio. Further, the auxiliary input jack 748 provides video. The input jacks 746 and 747 provide the respective right audio and left audio from an auxiliary unit connected to the jacks or from leads 750 and 752 that are connected to the second and fourth pins of a multi-pin connector 756 that forms a portion of the connector 541. The multi-pin connector 756 mates with a respective multi-pin connector 760 disposed on a video module 740, 742 or 744. Therefore the right and left audio signals from the video module 740, 742 or 744 mounted on the first housing section 511 of the portable interface unit are coupled via leads 750 and 752- through the respective jacks 746 and 747 contained on the housing section 513 and from these jacks via leads 762 and 764 to the modulator 720 of the housing section 511. Similarly, the video signals from the video module 740, 742 or 744 mounted on the housing section 511 is coupled via the seventh pin of the connector 760 and the connector 756 via a lead 754 to the video switch jack 748. From the switch jack 748 the video is coupled via a lead 766 to the modulator 720 contained within the housing section 511.

The modulator 720 modulates the video signals, right audio and left audio signals coupled thereto by the respective switch jacks 748, 746 and 747. The modulator 720 also modulates the digital control information coupled to the modulator 720 from a microprocessor controller 722. More particularly, the microprocessor controller 722 is coupled to a number of switches including a brightness up control switch 770, a brightness down control switch 772, a right volume up control 774 and a right volume down control 776 as well as a left volume up control 778 and a left volume down control 780. The microprocessor controller 722 is responsive to the actuation of these switches 770, 772, 774, 776, 778 and 780 to provide a digital control signal that is preferably a digital serial signal representing brightness control information as well as volume control information for the right and left earphones of the display system. This digital control signal is coupled to the modulator 720 for modulation with the video and audio signals. The power provided by the power supply module is combined with the modulated output of the modulator 720 via an inductor 721 and capacitor 723 to provide a composite signal on a lead 782 that is coupled to an output port 555. The output port 555 is matable with a lead connector 784 coupled to one end of the single wire cable 786 so as to couple the video, audio, power and control information to the circuitry of the head mounted display unit 12 as shown in Fig. 29E. As shown in Fig. 29B, the video module 740 is a television tuner video module having an antenna 434 for picking up television signals and a connector 790 that is matable with a cable T.V. adapter for coupling the T.V. tuner module to a cable T.V. pickup. The antenna 434 and the connector 790 are coupled to a UHF/VHF television tuner 792 that is powered by a power supply interface to regulate the power from the input connectors 730 and 732. The tuner 792 is responsive to a channel controller 796 so as to couple the received television signals associated with a selected channel to an IF system/demodulator unit 798. The channel controller 796 is responsive to manually actuable channel control input switches 800 and 802 to provide a selected channel control signal to the tuner 792. The right audio, left audio and video signals from the demodulator unit 798 are coupled to respective pins 2 , 4 and 7 of the connector 760 which mate with the respective second, fourth and seventh pins of the connector 756 as discussed above. The video module 742 shown in Fig. 29C is a 900 Mhz video receiver module that includes an antenna 810 coupled to a radio frequency amplifier and tuner 812, the tuner 812 being powered by a power supply interface 814 that provides regulated power to the tuner 812 in response to the power received via the power input connections 730 and 732. The output of the tuner 812 is coupled to a filter 816 the output of which is applied to a 70 Mhz demodulator 818. The output of the demodulator 818 is coupled to the right audio, left audio and video output pins 2, 4 and 7 of the connector 760 so as to mate with the second, fourth and seventh pins of the connector 756 disposed on the housing section 511 of the portable interface unit. Fig. 29D illustrates a video camera or camcorder having a multi-pin connector 760 for coupling right audio, left audio and video to the connector 756 and having power supply input connections 730 and 732 for receiving power from the connection 724 and 726 of the portable interface unit.

The circuitry contained in the head mounted display unit 12 in accordance with this embodiment of the present invention is illustrated in Fig. 29E. As shown therein, the circuitry includes a connector 850 for mating with a connector 852 carried on an end of the single wire cable 786 that is coupled to the output connector 555 disposed on the housing section 511 of the portable interface unit. The modulated composite video, audio, power and control information signal is coupled via the connector 850 to a demodulator 854. The demodulator 854 couples the control information to a microprocessor 856 that in turn couples the left audio control information to a left volume control unit 858 and couples the right audio control information to a right volume control unit 860. The respective left and right volume control units 858 and 860 also receive the left audio and right audio signals from the demodulator 854 and couple these signals to respective left and right earphones 861 and 863. The brightness control information is coupled by the microprocessor 856 via a digital to analog converter 865 to a backlight driver and power supply unit 864. The unit 864 is also coupled to the demodulator 854 to receive the demodulated power signal therefrom. The demodulator 854 couples the demodulated video signal to an LCD driver and video processor 862, the output of which is coupled to a liquid crystal display 866, the LCD 866 being such as described above for previous embodiments of the present invention. A backlight 868 for the liquid crystal display 866 is driven by the backlight driver 864. The LCD driver 862 is also coupled to a number of screwdriver adjustment inputs, generally designated 870, to allow the brightness, contrast, color, and tint of the liquid crystal display ,866 to be adjusted.

A modular transmitter module 900 for use with the video receiver module 742 is shown in Fig. 30. The transmitter module 900 includes a power supply module connector 902 similar to the power supply connector 599 on the portable interface unit housing section 513. This power supply module connector 902 includes positive and negative battery input connections 904 and 906 as well as an external DC power jack 908. The jack 908 may be coupled to a battery eliminator 910 such as an AC adapter or DC adapter, as discussed above. Power from the power supply module is coupled to a switcher power supply 912, the output of which provides +12 volts and +5 volts to a 70 Mhz modulator 914. Power is also coupled from the power supply module via leads 925 and 927 to battery output connections 924 and 926 that form a portion of a connector 920. The connector 920 also includes a multi-pin connector 922 such as the connector 756 so as to be able to mate with the respective multi-pin connectors 760 and the positive and negative battery input connections 730 and 732 of the respective TV tuner module 740 or a camcorder 744. Three phono jacks are provided to couple auxiliary inputs to the transmitter module, as discussed above, for the jacks 746, 747, and 748. The phono jacks 928 and 929 provide a respective input connection for right audio and left audio signals, whereas the jack 930 provides an input connection for video signals from the auxiliary input units 950, 951, or 952. The phono switch jacks couple right audio, left audio, and video received via leads 932, 933, and 934 to respective leads 936, 937, and 938 input to the 70 Mhz modulator 914. Alternatively, the jacks couple the right audio signals, left audio signals, and video received from the auxiliary input units 950, 951 or 952 to the 70 Mhz modulator 914 via the leads 936, 937, and 938. The 70 Mhz modulator 914 modulates the audio and video signals applied thereto and couples the modulated signals to a 900 Mhz modulator 916 for radio frequency modulation thereof. The 900 Mhz modulator 916 is coupled to an antenna 954 for transmission to a receiver module 742 that is mounted on the first housing section 511 of the portable interface unit. It is noted that the housing for the transmitter module 900 may be the same as the housing 500 as discussed above.

As seen from the above, the transmitter module 900 can be utilized with the same power supply modules and TV tuner module and camcorder modules as used with the portable interface unit shown in Fig. 29A. Therefore, the system of the present invention is extremely flexible for use in a large number of diverse applications. Because of the modularity of the system the user has great flexibility in selecting only those modules necessary for his particular application without requiring the purchase of other modules. However, the system is easily expandable.

Many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as described hereinabove. PAGE INTENTIONALLY LEFT BLANK

Claims

1. A video display system comprising: a head mounted display unit including a video display for displaying video information and a frame to support said unit on a users head; earphones responsive to received audio signals to project sound; and a portable interface unit remote from said head mounted display unit for receiving video signals representing a video image and for receiving audio signals representing sound to accompany said video image, said portable interface unit including a power supply to provide a power signal and said portable interface unit coupling said received video signals to said video display, said received audio signal to said earphones and said power signal to said head-up display unit to provide power thereto.

2. A video display system as recited in Claim 1 wherein said video and audio signals are coupled from sa d portable interface unit to said head mounted display unit via a single lead.

3. A video display system as recited in claim 1 wherein said power signal is coupled from said portable interface unit to said head mounted display unit via said single lead.

4. A video display system as recited in Claim 1 wherein said portable interface unit includes a modulation circuit for combining said video signals with said audio signals to generate a composite signal to be carried by a single lead in said cable to said head mounted display unit and said head mounted display unit includes means mounted on said frame for demodulating said composite signal to retrieve therefrom said audio signals and said video signals, said video signals being coupled to said video display and said audio signals being coupled to said earphones from said demodulating means.

5. A video display system as recited in Claim 1 wherein said portable interface unit includes a television broadcast tuner for receiving television video signals.

6. A video display system as recited in claim 1 wherein said portable interface unit includes an input for receiving audio and video signals from a video monitor.

7. A video display system as recited in claim 6 wherein said video monitor is a video recorder.

8. A video display system as recited in claim 1 wherein said portable interface unit includes an input for receiving video signals from a computer.

9. A video display system as recited in Claim 1 wherein said portable interface unit includes a receiver for receiving radio frequency modulated signals including video information and audio information and a demodulator coupled to said receiving means for demodulating said received signal to provide a video signal representing said video information and at least one audio signal representing said audio information.

10. A video display system as recited in claim

I wherein said portable interface unit is carried on a user's clothing.

11. The video display system as recited in claim 1 wherein said video display includes a liquid crystal display and optics including a viewing mirror disposed opposite said liquid crystal display to project said enlarged image wherein a user views said enlarged image through said mirror.

12.- A video display system as recited in claim

II wherein said liquid crystal display is a thin film transistor liquid crystal display.

13. A video display system as recited in claim 11 wherein said viewing mirror is disposed in the periphery of said user's field of view.

14. A video display system as recited in claim 11 wherein an optical path defined by said display, viewing mirror and the user's eye is adjustable.

15. A video display system comprising: a head mounted display unit including a video display for displaying video information and a frame to support said unit on a users head; a portable interface unit for receiving video signals representing a video image and for receiving audio signals representing sound to accompany said video image, said portable interface unit including a modulation circuit for combining said video signals with said audio signals to generate a composite signal; and means mounted on said frame of said head mounted display unit for demodulating said composite signal from said portable device to retrieve therefrom said audio signals and said video signals, said video signal being coupled to said video display; and at least one speaker coupled to said demodulating means to receive said audio signals therefrom to project said sound.

16: A video display system as recited in claim 15 wherein said portable interface unit includes a D.C. power supply and said modulation circuit is coupled to said D.C. power supply to combine a D.C. signal with said video and audio signals, said D.C. component of said composite signal powering said head mounted display unit.

17. A video display system as recited in Claim 15 wherein said portable interface unit includes a receiver for receiving radio frequency modulated signals including video information and audio information and a demodulator coupled to said receiving means for demodulating said received signal to provide a video signal representing said video information and at least one audio signal representing said audio information.

18. A video display system as recited in Claim 15 wherein said portable interface unit includes a television broadcast tuner for receiving television video signals.

19. A video system as recited in Claim 15 wherein said portable interface unit includes an input for receiving audio and video signals from a video recorder.

20. The video display system as recited in claim 15 wherein said video display includes a liquid crystal display and optics including a viewing mirror disposed opposite said liquid crystal display to project said enlarged image.

21. A video display system as recited in claim 15 wherein said liquid crystal display is a thin film transistor liquid.crystal display.

22. A video display system as recited in claim 15 wherein said viewing mirror is disposed in the periphery of said user's field of view.

23. A video display system as recited in claim 15 wherein an optical path defined by said display, viewing mirror and the user's eye is adjustable.

24. A video display system comprising; a head mounted display unit including a video display for displaying video information and a frame to support the display on a users head; and a portable interface unit having a plurality of inputs for receiving video signals from a plurality of sources including a television broadcast and having a video output, one of said inputs including a television broadcast tuner for receiving said television broadcast, said portable interface unit including a video selection input actuable by a user to couple one of said plurality of inputs to said output, said output being coupled to said video display.

25. A video display system as recited in Claim 24 wherein said portable interface unit includes an input for a video monitor.

26. A video display system as recited in Claim 24 wherein said portable interface unit is mounted on said head mounted display unit.

27. A video display system as recited in Claim 24 wherein one of said inputs of said portable interface unit includes a receiver for receiving radio frequency modulated signals including video information and a demodulator coupled to said receiving means for demodulating said received signal to provide a video signal representing said video information.

28. A video display system as recited in claim 27 including speakers and wherein said modulated signals include audio information, said receiving means demodulating said modulated audio signals to provide said audio signals to said speakers.

29. The video display system as recited in claim 24 wherein said video display includes a liquid crystal display and optics including a viewing mirror disposed opposite said liquid crystal display to project said enlarged image.

30; A video display system as recited in claim 24 wherein said liquid crystal display is a thin film transistor liquid crystal display.

31. A video display system as recited in claim 24 wherein said viewing mirror is disposed in the periphery of said user's field of view.

32. A video display system as recited in claim 24 wherein an optical path defined by said display, viewing mirror and the user's eye is adjustable.

33. A video display system comprising: a head mounted display unit including a video display for displaying video information and a frame to support the display on a users head; a portable interface unit including means for receiving radio frequency modulated signals including video information and a demodulator coupled to said receiving means for demodulating said received signals to provide a video signal representing said video information, said portable interface unit being coupled to said video display for providing said video display signal thereto for the display of said video information.

34. A video display system as recited in Claim 33 wherein said portable interface unit is mounted on said head mounted display unit.

35. A video display system as recited in claim 33 including speakers and wherein said modulated signals include audio information, said receiving means demodulating said modulated audio signals to provide said audio signals to said speakers.

36. A video display system as recited in Claim 33 wherein said portable interface unit includes a television broadcast tuner for receiving television broadcast video signals and switch means disposed between said tuner and said radio frequency receiving means and an output of said portable device for selectively coupling video signals from said tuner or said radio frequency receiving means to said output.

37. The video display system as recited in claim 33 wherein said video display includes a liquid crystal display and optics including a viewing mirror disposed opposite said liquid crystal display to project said enlarged image.

38. A video display system as recited in claim 33 wherein said liquid crystal display is a thin film transistor liquid crystal display.

39. A video display system as recited in claim 33 wherein said viewing mirror is disposed in the periphery of said user's field of view.

40. A video display system as recited in claim 33 wherein an optical path defined by said display, viewing mirror and the user's eye is adjustable.

41. A video display system for use with a video source providing video signals comprising: a modulator for radio frequency modulating said video source's video signals; means coupled to said modulating means for transmitting said radio frequency modulated signals; a head mounted display unit including a video display for displaying video information and a frame to support the video display on a users head; and a portable interface unit including a receiver for receiving said radio frequency modulated signals and a demodulator coupled to said receiving means for demodulating said received signals to provide a video signal representing said video information, said portable interface unit being coupled to said video display for providing said video signal thereto for the display of said video information.

42. A video display system as recited in claim 41 wherein said video source includes a television broadcast tuner for receiving a television broadcast, said modulator modulating a received television broadcast for transmission to said portable interface unit.

43. A video display system as recited in Claim 41 wherein said transmitter is coupled to a plurality of video monitors to transmit in a time controlled manner video signals from each of said video monitors.

44. A video display system as recited in Claim 41 wherein said portable device is mounted on said head mounted display.

45. A video display system for use with a plurality of video signal sources comprising: means for modulating video signals for transmission to a remote device; a switching device coupling the video signals from each of said sources one at a time to said modulating means for transmission. a head-up display unit remote from said modulating means and including a video display for displaying video information and a frame to support said unit on a users head; and a receiver coupled to said video display for receiving said transmitted, modulated video signals, said receiver demodulating said modulated signals to provide video signals to said video display.

46. A video display system comprising: a head mounted display unit including a video display for displaying video information and a frame to support said unit on a user's head; a portable interface unit for receiving video signals- representing a video image, said portable interface unit including a power supply to provide a power signal and means for combining said video signals and said power signal to generate a composite signal; and means mounted on said frame of said head mounted display unit for demodulating said composite signal from said portable device to retrieve therefrom said video signals and said power signal, said video signals and said power signal being coupled to said video display.

47. A video display system as recited in claim 46 including at least one speaker coupled to said demodulating means to receive an audio signal therefrom to project sound and wherein said portable interface unit includes means for receiving audio signals and including a modulator for combining said received audio signals with said video signals to generate said composite signal; said demodulating means demodulating said composite signal to retrieve said audio signal therefrom, said audio signal from said demodulating means being coupled to at least one speaker.

48. A video display system as recited in claim 46 wherein said portable interface unit includes a brightness control input to provide brightness control information for said head mounted display unit and including a modulator for combining said brightness control information with said video signals to provide said composite signal and said demodulating means demodulating said composite signal to retrieve therefrom said brightness control information, said brightness control information being coupled to said video display.

49. A video display system as recited in claim 47 wherein said portable interface unit, includes a volume control input to provide volume information and including a modulator for combining said volume control information with said video and audio signals to provide said composite signal and said demodulating means demodulating said composite signal to retrieve therefrom said volume information, said volume information being coupled to at least one speaker.

50. A portable interface unit for providing power and video signals to a head mounted display system, said unit comprising: a housing having a power supply mounting wall with a first connector disposed therein for connection to a power supply module, said housing having a video module mounting wall with a second connector disposed therein for connection to a video module and said housing having an output port for outputting video signals and power to said head mounted display system; and interface circuitry disposed in said housing and coupled between said first connector, said second connector and said output port to couple power input to said first connector to said output port and to couple video signals input to said second connector to said output port.

51. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said power supply mounting wall is disposed opposite said video module mounting wall.

52. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said power supply mounting wall is disposed adjacent to said video module mounting wall.

53. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said housing includes a first housing section, a second housing section and a hinge section disposed between said first and second housing sections to allow said first and second housing sections to be moved between a closed position and an extended position, said power supply mounting wall being disposed on said first housing section and said video module mounting wall being disposed on said second housing section such that in said extended position said power supply mounting wall is adjacent said video module mounting wall and in said closed position said power supply mounting wall is on an opposite side of said housing from said video module mounting wall.

54. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 53 wherein a portion of said interface circuitry is disposed in said first housing section, a portion of said interface circuitry is disposed in said second housing section and further including an electrical connector that extends through said hinge section into said first and second housing sections to connect said interface circuitry contained in said first and second housing sections.

55. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said interface circuitry includes a means for combining said video signals and said power to provide a composite signal coupled to said output port for said head mounted display unit.

56. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 55 wherein said housing includes a brightness control input mounted thereon to provide brightness control information for said head mounted display system and including a modulator for combining said brightness control information with said video signals to provide said composite signal.

57. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 55 wherein said head mounted display system includes an audio system and said second connector couples video signals and audio signals from a connected video module to said interface circuitry and including a modulator for combining said video signals and said audio signals to provide a composite signal coupled to said output port for said head mounted display unit.

58. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 57 wherein said housing includes a volume control input mounted thereon to provide volume information for said audio system of said head mounted display system and including a modulator for combining said volume control information with said video and audio signals to provide said composite signal.

59. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said first connector is connectable to a battery power supply module.

60. A portable interface unit for providing power and video signals to a head mounted display system as recited in . claim 50 wherein said first connector is connectable to a power supply module having a jack for an electrical wall outlet.

61. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein, said head mounted display system includes an audio system and said second connector is connectable to a television tuner video module that provides video and audio signals to said second connector, said second connector coupling said video and audio signals to said interface circuitry and said interface circuitry coupling said video and audio signals to said output port.

62. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 61 wherein said second connector couples power from said interface circuit to said television tuner video module to power said television tuner module.

63. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said second connector is connectable to a video module that receives radio frequency modulated video signals and provides signals representing said receiver video signal to said second connector.

64. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 63 wherein said second connector couples power from said interface circuit to said radio frequency video receiving module to power said module.

65. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 63 wherein said head mounted display system includes an audio system and said radio frequency video receiving module receives radio frequency modulated video and audio signals and provides signals representing said received video and audio signals to said second connector, said second connector coupling said video and audio signals to said interface circuitry and said interface circuitry coupling said video and audio signals to said output port.

66. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 50 wherein said second connector is connectable to a video camera video module that provides video to said second connector.

67. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 66 wherein said second connector couples power from said interface circuit to said video camera to power said video camera.

68. A portable interface unit for providing power and video signals to a head mounted display system, said unit comprising: a housing having.a power supply mounting wall with a first connector disposed therein for connection to a power supply module, said housing having a video module mounting wall with a second connector disposed therein for connection to one of a plurality of video modules and said housing having an output port for outputting video signals and power to said head mounted display system; interface circuitry disposed in said housing and coupled between said first connector, said second connector and said output port to couple power input to said first connector to said output port and to couple video signals input to said second connector to said output port; a power supply module having a housing with third connector disposed in a wall of said housing, said connector mating with said first connector to provide power from said power supply module to said interface circuit through said first and second connectors; and a video module having a housing with a fourth connector disposed in a wall of said housing, said fourth connector mating with said second connector to provide video signals from said video module to said interface circuit.

69. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said interface circuitry includes a means for combining said video signals and said power to provide a composite signal coupled to said output port for said head mounted display unit.

70. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 69 wherein said housing includes a brightness control input mounted thereon to provide brightness control information for said head mounted display system and including a modulator for combining said brightness control information with said video signals to provide said composite signal.

71. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 69 wherein said head mounted display system includes an audio system and said second connector couples video signals and audio signals from a connected video module to said interface circuitry and including a modulator for combining said video signals and said audio signals to provide a composite signal coupled to said output port for said head mounted display unit.

72. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 71 wherein said housing includes a volume control input mounted thereon to provide volume information for said audio system of said head mounted display system, said modulator being coupled to said volume control input to combine said volume control information with said video and audio signals to provide said composite signal.

73. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said power supply module is a battery power supply module.

74. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said power supply module incudes a jack for an electrical wall outlet.

75. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said head mounted display system includes an audio system and video module includes a television tuner.

76. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 75 wherein said second connector couples power from said interface circuit to said television tuner video module to power said television tuner module.

77. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said video module receives radio frequency signals and provides signals representing said received video signals to said second connector..

78. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 77 wherein said second connector couples power from said interface circuit to said radio frequency video receiving module to power said module.

79. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 77 wherein said head mounted display system includes an audio system and said radio frequency video receiving module receiver radio frequency modulated video and audio signals and provides signals representing said received video and audio signals to said second connector, said second connector coupling said video and audio signals to said interface circuitry and said interface circuitry coupling said video and audio signals to said output port.

80. A portable interface unit for providing power and video signals to a head mounted display system -as recited in claim 68 wherein said video module is a video camera that provides video to said second connector.

81. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 80 wherein said housing includes a brightness control input mounted thereon to provide brightness control information for said head mounted display system, said modulator being coupled to said brightness control input to combine said brightness control information with said video and power signals to provide said composite signal.

82. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said power supply mounting wall is disposed opposite said video module mounting wall.

83. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said power supply mounting wall is disposed adjacent to said video module mounting wall.

84. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein said housing includes a first housing section, a second housing section and a hinge section disposed between said first and second housing sections to allow said first and second housing sections to be moved between a closed position and an extended position, said power supply mounting wall being disposed on said first housing section and said video module mounting wall being disposed on said second housing section such that in said extended position said power supply mounting wall is adjacent said video module mounting wall and in said closed position said power supply mounting wall is on an opposite side of said housing from said video module mounting wall.

85. A portable interface unit for providing power and video signals to a head mounted display system as recited in claim 68 wherein a portion of said interface circuitry is disposed in said first housing section, a portion of said interface circuitry is disposed in said second housing section and further including an electrical connector that extends through said hinge section into said first and second housing to connect said interface circuitry contained on said first and second housing sections.

86. A portable video transmitter unit for transmitting radio frequency modulated video signals comprising: a power supply module having a first connector; a source of video signals having a second connector; a transmitter module having a third connector mounted on a first surface thereof and matable with said power supply module to couple power to said transmitter module and having a fourth connector mounted"on a second surface thereof and matable with said second connector to couple video signals from said video source to said transmitter module, said transmitter module including a radio frequency modulator coupled to said fourth connector for radio frequency modulating said video signals from said source for transmission of said signals.

87. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 86 wherein said video source is mounted on said second surface of said transmitter module.

88. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 87 wherein said power supply module is mounted on said first surface of said transmitter module.

89. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 88 wherein said first surface of said transmitter module is adjacent to said second surface of said transmitter module.

90. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 88 wherein said first surface of said transmitter module is on a side of said transmitter module opposite to a side of said transmitter module on which said second surface is disposed.

91. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 86 wherein said video source includes a television tuner and said second and fourth connectors couple video and audio signals from said television tuner to said transmitter module for radio frequency modulation of said video and audio signals for transmission thereof.

92. A portable transmitter unit for transmitting radio frequency modulated .signals as recited in claim 86 wherein said second and fourth connectors couple power from said transmitter module to said television tuner.

93. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 86 wherein said video source includes a video monitor.

94. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 93 wherein said video monitor is a video camera.

95. A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 93 wherein said second and fourth connectors couple power from said transmitter module to said video monitor.

96." A portable transmitter unit for transmitting radio frequency modulated signals as recited in claim 86 wherein said video source incudes a computer.

97. A portable interface unit for providing power and video signals to a head mounted display system, said unit comprising: a power supply module having a first connector; a source of video signals having a second connector; an interface module having a third connector mounted on a first surface thereof and matable with said power supply module to couple power to said interface module, a fourth connector mounted on a second surface of said interface module and matable with said second connector to couple video signals from said video source to said interface module and an output port for outputting signals to said head mounted display system, said interface module combining said power and said video signals to form a composite signal coupled to said output port.

98. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 97 wherein said video source is mounted on said second surface of said interface module. -

99. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 98 wherein said power supply module is mounted on said first surface of said interface module.

100. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 99 wherein said first surface of said transmitter module is adjacent to said second surface of said interface module.

101. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 99 wherein said first surface of said interface module is on a side of said interface module opposite to a side of said interface module on which said second surface is disposed.

102. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 97 wherein said video source includes a television tuner and said second and fourth connectors couple video and audio signals from said television tuner to said interface module.

103. A portable interface module unit for transmitting radio frequency modulated signals as recited- in claim 97 wherein said second and fourth connectors couple power from said interface module to said television tuner.

104. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 97 wherein said video source includes a video monitor.

105. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 104 wherein said video monitor is a video camera.

106. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 104 wherein said second and fourth connectors couple power from said interface module to said video monitor.

107. A portable interface module unit for transmitting radio frequency modulated signals as recited in claim 97 wherein said video source includes a computer.