US20050146777A1 - Wavelength discriminated image dithering - Google Patents
Wavelength discriminated image dithering Download PDFInfo
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- US20050146777A1 US20050146777A1 US10/750,284 US75028403A US2005146777A1 US 20050146777 A1 US20050146777 A1 US 20050146777A1 US 75028403 A US75028403 A US 75028403A US 2005146777 A1 US2005146777 A1 US 2005146777A1
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/10—Beam splitting or combining systems
- G02B27/14—Beam splitting or combining systems operating by reflection only
- G02B27/143—Beam splitting or combining systems operating by reflection only using macroscopically faceted or segmented reflective surfaces
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
- G02B27/10—Beam splitting or combining systems
- G02B27/1006—Beam splitting or combining systems for splitting or combining different wavelengths
- G02B27/102—Beam splitting or combining systems for splitting or combining different wavelengths for generating a colour image from monochromatic image signal sources
- G02B27/1026—Beam splitting or combining systems for splitting or combining different wavelengths for generating a colour image from monochromatic image signal sources for use with reflective spatial light modulators
- G02B27/1033—Beam splitting or combining systems for splitting or combining different wavelengths for generating a colour image from monochromatic image signal sources for use with reflective spatial light modulators having a single light modulator for all colour channels
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
- H04N9/3111—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators for displaying the colours sequentially, e.g. by using sequentially activated light sources
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3141—Constructional details thereof
- H04N9/315—Modulator illumination systems
- H04N9/3164—Modulator illumination systems using multiple light sources
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N9/00—Details of colour television systems
- H04N9/12—Picture reproducers
- H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
- H04N9/3179—Video signal processing therefor
- H04N9/3188—Scale or resolution adjustment
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- Optics & Photonics (AREA)
- Projection Apparatus (AREA)
Abstract
A method and system for providing a dithered image is provided. In one embodiment, a projector system for providing a dithered image includes a light source comprising a first and a second light emitting diode (LED). The first LED is operable to transmit a first light beam at a first peak wavelength. The second LED is operable to transmit a second light beam at a second peak wavelength. The first peak wavelength is disparate from the second peak wavelength. A digital micromirror device (DMD) is operable to receive the first beam and the second beam and selectively pass a first portion of the first beam and a second portion of the second beam along a projection path. A dichroic reflector operable to receive the first portion and the second portion, passively pass the first portion along the projection path, and substantially reflect the second portion within a wavelength range. An optical mirror operable to receive the substantially reflected second portion and reflect the substantially reflected second portion along an offset path.
Description
- This invention relates generally to displaying images, and more particularly to wavelength discriminated image dithering.
- Light processing systems often involve combining various primary colors of light on a display such that a particular color and/or image is produced. One way of effecting such combination is through the use of digital micromirror devices (DM1) available from Texas Instruments. In general, primary colors of light are shined on a DMD array having numerous micromirrors. Each micromirror is selectively controlled to reflect each primary color of light onto a particular portion of a display, such as a pixel. Each micromirror can be used to switch a pixel on or off by changing an angle of a corresponding mirror. The pixels of the DMD can maintain their “on” or “off” state for controlled display times. Conventionally, either three or more separate color-specific light sources are used or a single white-light source is used in combination with a color wheel to provide at least three primary colors that can be mixed on the display. Each individual micromirror reflects a color-specific light for an appropriate period of time such that the viewer's eye integrates the various colors and perceives an image made up of a plurality of different colors.
- Conventionally, each micromirror device corresponds to a pixel on the display. Thus the resolution of the display is limited by the number of micromirrors that can be effectively manufactured. Consumers are desirous of having increased resolution. Thus, approaches to increase the resolution of the display have been developed.
- One such approach is sometimes referred to as dithering, in which the display is shifted a fraction of a pixel, giving the illusion of double the resolution than that which would normally occur. One challenge with such a technique is achieving the shift. One approach utilizes a mirror that receives the light otherwise intended for the display and reflects it onto the display in a shifted position or a non-shifted position.
- A method and system for providing a dithered image is provided. In one embodiment, a projector system for providing a dithered image includes a light source comprising a first and a second light emitting diode (LED). The first LED is operable to transmit a first light beam at a first peak wavelength. The second LED is operable to transmit a second light beam at a second peak wavelength. The first peak wavelength is disparate from the second peak wavelength. A digital micromirror device (DMD) is operable to receive the first beam and the second beam and selectively pass a first portion of the first beam and a second portion of the second beam along a projection path. A dichroic reflector operable to receive the first portion and the second portion, passively pass the first portion along the projection path, and substantially reflect the second portion within a wavelength range. An optical mirror operable to receive the substantially reflected second portion and reflect the substantially reflected second portion along an offset path.
- Technical advantages of some embodiments of the invention may include providing an enhanced projector system for displaying an image. Other advantages of one or more embodiments may include enhancing the image of a projected image by dithering the projected image. Yet another advantage of one or more embodiments of the present invention may include providing a projected image and an offset image without the use of electrical or mechanical devices.
- It will be understood that the various embodiments of the present invention may include some, all, or none of the enumerated technical advantages. In addition other technical advantages of the present invention may be readily apparent to one skilled in the art from the figures, description, and claims included herein.
- For a more complete understanding of the present invention and features and advantages thereof, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
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FIG. 1 is a block diagram of a projection system; -
FIG. 2A and 2B illustrates the path that a projection beam and a dithering beam traverse, respectively, in the projection system ofFIG. 1 ; -
FIG. 3A is a graph of relative intensity versus wavelength for a light source illustrated inFIG. 1 ; and -
FIG. 3B is a graph of relative transmittance versus wavelength for light incident on a dichroic reflector illustrated inFIG. 1 ; and -
FIG. 4 illustrates an example method for projection a dithered image. -
FIG. 1 illustrates one embodiment of aprojection display system 100 that uses adithering element 112 to provide a dithered image.Projection display system 100 includes adigital signal processor 120, aprojector 114, adithering element 112, and ascreen 110. In general,digital signal processor 120 provides image information associated with a color image toprojector 114. Ditheringelement 112 receives color-specific images fromprojector 114 and provides a projection image 133A and an offset image 133B for display onscreen 110. Other embodiments ofprojection display system 100 may be employed without departing from the scope of this disclosure. -
Projector 114 is optically coupled to ditheringelement 112 and is operable to provide color-specific image to ditheringelement 112. A “color-specific image”, as used herein, means a monochromatic portion of a color image.Projector 114 is electrically coupled todigital signal processor 120 and is operable to receive information associated with a color image for display onscreen 110. Based on this information,projector 114 may sequentially provide color-specific images such that the superposition of the color-specific images may be perceived as the color image. For example,projector 114 may sequentially provide a red, green, and blue image; however, the display of color-specific images is not limited to a sequential display but may be displayed in any order or pattern. Each color-specific image may be spatially disparate from other color-specific images. Referring toFIG. 1 ,projector 114 includes aspatial modulator 118 optically coupled to alight source 116.Modulator 118 receives a color-specific light beam fromlight source 116 and provides a spatially modulated light beam to ditheringelement 112. Bothlight source 116 anddithering element 112 may be optically coupled tomodulator 118 through lenses, collimators, or other suitable optical devices. -
Light source 116 is a device that emits, in one embodiment, color-specific light beams in the direction ofmodulator 118 to initiate processing of the color-specific light beam and is operable to receive an electric signal fromdigital signal processor 120. Additionally,light source 116 is operable to provide color-specific light beams tomodulator 118. A “color-specific light beam,” as used herein, means a light beam that emits narrow-bandwidth radiation such that the distribution of light is perceived as monochromatic. For example, a color-specific light beam may include a green light beam centered around 506 nm with a bandwidth of 40 nm. Narrow-bandwidth sources may include semiconductor lasers, light-emitting diodes (LEDs), injection laser diodes (ILDs), vertical cavity surface emitting diodes (VCSELs), an array of light sources, lasers, or any other suitable source that emits light within a narrow bandwidth. Alternatively,light source 116 may comprise a color wheel and a white-light source. A color wheel is a disk-shaped member in which primary colored (e.g., red, green, and blue) filters are arranged radially. In this case, the color wheel is rotationally driven while the white-light source provide illumination light for the filters. As a result, the color wheel sequentially separates the illumination light into the primary color wavelength regions, such as red, green, and blue wavelength regions. As compared to narrow-bandwidth sources, white light sources are broadband sources that are perceived as achromatic or white. - In the illustrated embodiment,
light source 116 includes light-emitting diodes (LEDs) 122. Each LED 122 is electrically coupled todigital signal processor 120 via a digital to analog (D/A)converter 126 and optically coupled tomodulator 118. Each LED 122 transmits a color-specific light beam within a narrow-bandwidth centered around a peak wavelength. As discussed in more detailed below,FIG. 2A illustrates an example spectrum oflight source 116. In the illustrated embodiment,light source 116 includes ared LED 122 a, ared LED 122 b, agreen LED 122 c, agreen LED 122 d, and ablue LED 122 e. Alternatively,light source 116 may include a first and a second blue LED 122. Bothred LED 122 a andred LED 122 b transmit spectrally proximate red light beams in the direction ofmodulator 118. Spectrally proximate light beams, as used herein, means that each light beam is perceived to be substantially the same color but the peak wavelength of both is sufficiently separated on the electromagnetic spectrum such that optical components can discriminate between each beam. Green LED 122 c andgreen LED 122 d transmit spectrally proximate green light beams in the direction ofmodulator 118. Although, not illustrated, several optical components may exists betweenlight source 116 andmodulator 118 to assist in providingmodulator 118 at least a portion of the transmit color-specific light beam. Furthermore, when referring to providing a color-specific light beam tomodulator 118 this contemplates that the entire emitted color-specific light beam may not be provided tomodulator 118. -
Digital signal processor 120 is coupled tolight source 116 andmodulator 118. In certain embodiments,digital signal processor 120 is coupled tolight source 116 through D/A converter 126. According to particular embodiments,digital signal processor 120 generates and digitizes an input sequence that driveslight source 116. The input signal may be digitized via pulse-code-modulation (PCM) or pulse-width-modulation (PWM) to produce an input signal with digital precision. If present, D/Aconverter 126 converts the digital input signal to an analog control signal, which is communicated to and controlslight source 116. If the input sequence was digitized using PWM, then D/A converter 126 is not necessary.Digital signal processor 120 is further operable to configure andprogram modulator 124 to allowmodulator 124 to process analog optical signals with digital precision. -
Modulator 118 may comprise any device capable of selectively communicating at least some of the illumination light beam along a projection path 127 and/or along an off-state light path 129. In the illustrated embodiment,modulator 118 comprises a digital micromirror device (DMD) 124.DMD 124 is a digital form of a spatial light modulator that acts as a matrix mask configured bydigital signal processor 120. In general,DMD 124 processes light beams received fromlight source 116 into a color specific image, based on the configuration ofDMD 124, and reflects the resulting image to ditheringelement 112 along projection path 127. In one embodiment,DMD 124 is an electromechanical device including a pixel array, such as a 768×1024 array, of digital tilting mirrors or baseline binary pixels or mirrors. Each binary mirror may tilt by a plus or minus angle (e.g., 10 or 12 degrees) for the active “on” or “off” positions. To permit the mirrors to tilt, each is attached to one or more actuators such as, for example, hinges mounted on support posts over underlying control circuitry. The control circuitry provides electrostatic forces that cause each mirror to selectively tilt. Incident light on the mirror array is reflected by the “on” mirrors along the projection path 127A and by the “off” mirrors along the off-state path 129. The configurable pattern of “on” versus “off” mirrors forms, in part, the color-specific image. Accordingly, ditheredimage 133 is light that is reflected by the “on” mirrors inDMD 124 and is generally projected to ditheringelement 112. - Dithering
element 112 is, in one embodiment, operable to receive spatially modulated light beams fromprojector 114 and passively drop a portion of a light beam transmitted along projection path 127A to provide an offsetbeam 129 with the remaining light passing through ditheringelement 112 along projection path 127B. Passively, as used herein, means without the use of power, electricity, and/or moving parts. Furthermore, ditheringelement 112 is, in one embodiment, operable to receive at least two spectrally proximate light beams and passively drop one of the beams from projection path 127 to provide the dropped beam along offsetpath 129, with the remaining beam passing through the dithering element along projection path 127B. For example, ditheringelement 112 may be operable to receive the spectrally proximate red light beams associated with red oneLED 122 a and red twoLED 122 b. In this embodiment, ditheringelement 112 is operable to pass the wavelength associated with red oneLED 122 a along projection path 127B and passively drop the wavelength associated with red two LED 122B to provide the beam along offsetpath 129. Ditheringelement 112 may comprise dichroic reflectors, fixed Bragg gratings, sub-band rejection filters, lenses, mirrors, prisms, any combination of the foregoing, or other optical components operable to passively drop light beams within a bandwidth of the electromagnetic spectrum and provide an offset beam. While ditheringelement 112 is illustrated as disparate fromprojector 114,projector 114 may comprise ditheringelement 112. - Dithering
element 112 includes, in the illustrated embodiment, an optical selectingelement 128 and an opticaldirectional element 130. Optical selectingelement 128 is operable to receive a light beam transmitted along projection path 127A and route a portion of at least a color-specific light beam alongrejection path 131 while passing through the remaining wavelengths. In the illustrated embodiment, optical selectingelement 128 includes adichroic reflector 132 that is operable to reflect wavelengths within certain bandwidths alongrejection path 131, while passing the remaining wavelengths along projection path 127B. Adichroic reflector 132 may be formed by depositing a dielectric multilayer film on a given glass substrate. Optical selectingelement 128 may comprise other components operable to discriminate between spectrally proximate light beams. Opticaldirectional element 130 is operable to receive the reflected light beams transmitted alongrejection path 131 and pass the reflected light beam along offsetpath 129. In the illustrated embodiment, opticaldirectional element 130 includes anoptical mirror 134 operable to reflect an incident light beam along offsetpath 129. It will be understood that opticaldirectional element 130 may comprise other optical components operable to receive a light beam and pass the light beam along offsetpath 129, which may include lenses, mirrors, collimators, any combination of the foregoing, or any other suitable optical components. -
Screen 110 is operable to receive light beams transmitted along projection path 127B and offsetpath 129 to generate ditheredimage 133. A dithered image, as used herein, means spatially overlapping one image by a substantially similar image, which may be not be temporally overlapped. In the illustrated embodiment, ditheredimage 133 includes a projected image 133A and an offset image 133B. Both projected image 133A and offset image 133B may comprise spectrally proximate light. In this case, projected image 133A is overlapped by a substantially similar image in color and spatial modulation, i.e., the offset image 133B. In one embodiment, projected image 133A and offset image 133B are offset by one half a pixel horizontally and by one half a pixel vertically. In the illustrated embodiment, offset image 133B includes green and a red offset images whose display is temporally separated, and projection image 133B includes red, green, and blue images whose display is also temporally separated. Both red images may be temporally separated, and both green images may be temporally separated. Alternatively, both red images may be displayed simultaneously, and both green images may be displayed simultaneously. A sequential display of these images are perceived as a superposition of the various color-specific images resulting in a perceived display of the color image. - In one aspect of operation,
digital signal processor 120 receives digital information associated with a color image for reproduction onscreen 110.Digital signal processor 120 generates and digitizes an input sequence that drives each LED 122 independently. D/A converter 126 may convert the digital input signal to an analog control signal, which is communicated to and controls LEDs 122 independently. Additionally,digital signal processor 120 transmits control signals toDMD 124. According to the input signal,light source 116 transmits a color-specific light beam along initiallight path 125. For example, the light beam transmitted bylight source 116 may comprise a red light beam including red light generated byred LED 122 a and red light generated byred LED 122 b. Under certain operating conditions, the red light generated byred LED 122 a and the red light generated byred LED 122 b are not transmitted simultaneously and thus their transmission is temporally separated. Based on the control signal received byDMD 124, DMD alters the configuration of its micromirrors to spatially modulate the red light beam according to the image information and reflect the relevant light along projection path 127A.Dichroic reflector 132 receives the spectrally proximate red light beams, and reflects the red light beam associated withred LED 122 b alongrejection path 131 and passes through the red light beam associated withred LED 122 a along projection path 127B.Optical mirror 134 receives the red light beam transmitted alongrejection path 131 and reflects the received beam along offsetpath 129.Screen 110 receives the spectrally proximate red light beams transmitted along projection path 127B and the red light beam transmitted along offsetpath 129 such that the displayed beams spatially overlap to generate ditheredimage 133. As mentioned above, projection image 133A and offset image 133B may not temporally overlap. -
FIGS. 2A and 2B illustrated the transmission paths of two spectrally proximate light beams insystem 100. For example, theseFIG. 2A and 2B may illustrate the transmission path that red light beams emitted byred LED 122 b and red twoLED 122 b traverse, respectively. In particular,FIG. 2A illustrates aprojection path 136 of a light beam that passes through ditheringelement 112.Red LED 122 a emits narrow-band radiation within the red portion of the visible light spectrum.DMD 124 receives the red light beam and spatially modulates the beam. The spatially modulated beam is reflected generally toward ditheringelement 112. In this case, the red light fromred LED 122 a does not fall within the bandwidth reflected bydichroic reflector 132. As a result, this red light beam passes throughdichroic reflector 132 to screen 110, which displays projection image 133A generated by this red light beam. - In comparison,
FIG. 2B illustrates a ditheringpath 138 of a light beam that is passively dropped by ditheringelement 112.Red LED 122 b emits narrow-band radiation with the red portion of the visible light spectrum that is spectrally proximate light fromred LED 122 a.DMD 124 receives the red light beam and spatially modulates the beam such that the spatially modulated beam is substantially similar in color and spatial modulation to the red light transmitted along projection path 127. The spatially modulated beam is also transmitted toward ditheringelement 112. By comparison tored LED 122 a, the red light fromred LED 122 b does fall within the bandwidth reflected bydichroic reflector 132, which reflects this beam alongreflection path 131 tooptical mirror 134.Optical mirror 134 reflects this red light beam along offsetpath 129 toscreen 110, which displays offsets image 133B generated by the offset red light beam. Projection image 133A is spatially overlapped by offset image 133B, resulting in overlapping projection 133A with a copy of projection image 133A. -
FIG. 3A is a graph of relative intensity versus wavelength illustrating an example spectral distribution oflight source 116.Graph 140 includespeaks Peaks Peaks -
FIG. 3B is agraph 160 of relative transmittance versus wavelength ofdichroic reflector 132.Mesas dichroic reflector 132. In contrast,valleys dichroic reflector 132. As illustrated, green light emitted from green two LED 122D is substantially reflected bydichroic reflector 132. Red light emitted by red two LED 122B is substantially reflected bydichroic reflector 132. -
FIG. 4 illustrates a flowchart of anexample method 180 for providing a dithered image onscreen 110.Method 180 is described in respect tosystem 100. However, any other suitable system may usemethod 180 to provide a dithered image without departing from the scope of this disclosure. Generally,method 180 describesscreen 110 receiving a projection image and an offset image to produce ditheredimage 133. -
Method 180 begins atstep 182 wheredigital signal processor 120 receives image information. Image information may have originated from a variety of sources such as digital, digital compressed, digital graphics, analog composite, analog s-video, analog graphics, or any other suitable source. Next, atstep 184,digital signal processor 120 transmits commands tored LED 122 a andred LED 122 b via D/A converter 126. The input signals for bothLEDs Digital signal processor 120 also transmits commands toDMD 124 operable to change the configuration ofDMD 124 based on the color of the light beam transmitted byLED DMD 124 may be otherwise suitable based on the transmitting LED 122. Atstep 188,red LED 122 a transmits a red light beam at a first red wavelength.Red LED 122 b transmits a second red light beam at a disparate red wavelength that is spectrally proximate the first red wavelength atstep 190. As discussed above, under certain operating conditions, the red light beam transmitted byred LED 122 a and the red light beam transmitted byred LED 122 a are temporally separated. Next, atstep 192,DMD 124 receives the first red light beam transmitted along incidentlight path 125. Atstep 194,DMD 124 receives the second red light beam transmitted along incidentlight path 125.DMD 124 selectively passes at least a portion of the first red light beam alongprojection path 127 a based on its configuration. Atstep 198,DMD 124 selectively passes at least a portion of the second red light beam alongprojection path 127 a based onDMD 124's configuration.Dichroic reflector 132 receives the selectively passed portion of the first red light beam transmitted alongprojection path 127 a. Atstep 202,dichroic reflector 132 passes the selectively passed portion of the first red light beam through thedichroic reflector 132 and alongprojection path 127 b. Next, atstep 204,dichroic reflector 132 receives the selectively passed portion of the second red light beam transmitted alongprojection path 127 a. Atstep 206,dichroic reflector 132 reflects the selectively passed portion of the second red light beam along reflectedpath 131.Optical mirror 134 receives the reflected light beam transmitted along reflectedpath 131 atstep 208.Optical mirror 134 reflects the incident offset beam propagating along reflectedpath 131 along offsetpath 129 atstep 210. Atstep 212,screen 110 receives the pass through beam and the offset beam to display ditheredimage 133. - Although the present invention has been described with several embodiments, diverse changes, substitutions, variations, alterations, and modifications may be suggested to one skilled in the art, and it is intended that the invention encompass all such changes, substitutions, variations, alterations, and modifications as fall within the spirit and scope of the appended claims.
Claims (22)
1. A method for providing a dithered image in a digital light processing system, comprising:
transmitting a first light beam from a first light-emitting diode (LED) at a first wavelength and a second light beam from a second LED at a second wavelength, the first wavelength spectrally proximate the second wavelength;
receiving the first and second beam at a digital micromirror device (DMD);
selectively passing a first portion of the first beam and a second portion of the second beam received by the DMD along a projection path;
receiving the first and second portion of the first beam at a dithering element;
passively passing the first portion of the first beam along the projection path and the second portion along an offset path; and
directing the first portion and second portion on to a screen to provide a dithered image.
2. The method of claim 1 , the first LED comprising a first red LED, the second LED comprising a second red LED, the light source further comprising a first green LED transmitting at third peak wavelength, a second green LED transmitting at a fourth peak wavelength spectrally proximate the third peak wavelength, and a blue LED transmitting at a fifth peak wavelength, each peak wavelength disparate from other peak wavelengths.
3. The projector system of claim 2 , the dithering element comprising a dichroic reflector operable to substantially reflect the second and the fourth peak wavelengths.
4. A method for providing a dithered image, comprising:
transmitting a first light beam at a first peak wavelength and a second light beam at a second peak wavelength, the first peak wavelength disparate from the second peak wavelength;
selectively passing a first portion of the first beam and a second portion of the second beam received a projection path; and
passively passing the first portion of the first beam along the projection path and the second portion along an offset path.
5. The method of claim 4 further comprising directing the first portion and second portion on to a screen to provide a dithered image.
6. The method of claim 4 , the light source comprising a first red LED transmitting at the first peak wavelength and a second red LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
7. The method of claim 4 , the light source comprising a first green LED transmitting at the first peak wavelength and a second green LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
8. The method of claim 4 , the light source comprising a first blue LED transmitting at the first peak wavelength and a second blue LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
9. The method of claim 4 further comprising receiving the first and second light beam at a DMD.
10. The method of claim 4 further comprising receiving the first and second portion at a dithering element.
11. The method of claim 10 , the dithering element comprising a dichroic reflector operable to substantially reflect the second portion of the second beam within a wavelength range and an optical mirror to receive the substantially reflected second portion of the second beam and reflect the substantially reflected second portion along an offset path.
12. The method of claim 11 , the dichroic reflector operable to substantially reflect incident light within a first and a second wavelength range, the first wavelength range disparate from the second wavelength range.
13. A projector system for providing a dithered image, comprising:
a light source capable of transmitting at least a first light beam at a first peak wavelength and a second light beam at a second peak wavelength, the first peak wavelength disparate from the second peak wavelength;
a spatial light modulator operable to receive the first beam and the second beam and selectively pass a first portion of the first beam and a second portion of the second beam along a projection path; and
a dithering element operable to receive the first portion and the second portion and to passively pass the first portion along the projection path and the second portion along an offset path.
14. The projector system of claim 13 further comprising a screen operable to display the first portion and the second portion, the first displayed portion overlaps the second displayed portion by a fraction of a pixel.
15. The projector system of claim 13 , the light source comprising a first red LED transmitting at the first peak wavelength and a second red LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
16. The projector system of claim 13 , the light source comprising a first green LED transmitting at the first peak wavelength and a second green LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
17. The method of claim 13 , the light source comprising a first blue LED transmitting at the first peak wavelength and a second blue LED transmitting at the second peak wavelength, the first peak wavelength spectrally proximate the second peak wavelength.
18. The projector system of claim 15 , the light source further comprising a first green LED transmitting at a third peak wavelength, a second green LED transmitting at the fourth peak wavelength spectrally proximate the third peak wavelength, and a blue LED transmitting at a fifth peak wavelength, each wavelength disparate from other wavelengths, the third peak wavelength proximate the fourth peak wavelength.
19. The projector system of claim 13 , the spatial modulator comprising a DMD.
20. The projector system of claim 13 , the dithering element comprising a dichroic reflector operable to reflect at least a portion of light beams within a wavelength range.
21. The projector system of claim 20 , the dithering element further comprising an optical mirror operable to receive the reflected portion of light beams and reflect the reflected portion along the offset path.
22. The projector system of claim 20 , the dichroic reflector operable to substantially reflect incident light within a first and a second wavelength range, the first wavelength range disparate from the second wavelength range.
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