WO2007094386A1

WO2007094386A1 - Display and view angle control device used for the same

Info

Publication number: WO2007094386A1
Application number: PCT/JP2007/052678
Authority: WO
Inventors: Katsuhiko Morishita; Takehiko Sakai; Tsuyoshi Okazaki; Yoshiharu Kataoka; Chikanori Tsukamura
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-02-17
Filing date: 2007-02-15
Publication date: 2007-08-23

Abstract

Provided is a display capable of being adapted to various operation environments and applications by switching a display state between a wide view angle and a narrow view angle. The display includes a view angle control liquid crystal panel (2) at least one of the rear surface and the front surface of the display device. The view angle control liquid crystal panel (2) includes a liquid crystal cell (21) and a drive circuit. The liquid crystal cell (21) is arranged between a pair of polarization plates (13, 22). The liquid crystal cell (21) has an orientation film not subjected to a surface patterning process. A liquid crystal layer has an orientation direction regulated by a rib (203) formed at least one of transparent substrates (21a, 21b). The drive circuit changes the orientation state of a liquid crystal molecule (21c) of the liquid crystal layer of the view angle control liquid crystal panel (2) so as to switch the display state between the wide view angle and the narrow view angle.

Description

Specification

Display and viewing angle control device used therefor

Technical field

The present invention relates to a viewing angle control device capable of switching a viewing angle of a display between a wide viewing angle and a narrow viewing angle, and a display using the viewing angle control device.

Background art

[0002] In general, a display is required to have a viewing angle as wide as possible so that a clear image can be seen from any viewing angle. In particular, liquid crystal displays that have recently become widespread have been developed for various viewing angles because the liquid crystal itself has a viewing angle dependency. However, depending on the usage environment, it may be advantageous to have a narrow viewing angle so that only the user can see the displayed content. In particular, notebook personal computers, personal digital assistants (PDAs), or mobile phones are highly likely to be used in places where an unspecified number of people can exist, such as in trains and airplanes. In such a usage environment, it is desirable that the viewing angle of the display be narrow because the display content is not viewed by others in the vicinity from the viewpoint of confidentiality and privacy protection. Thus, in recent years, there has been an increasing demand for switching the viewing angle of a single display between a wide viewing angle and a narrow viewing angle depending on usage conditions. This requirement is not limited to liquid crystal displays, but is a common issue for arbitrary displays.

[0003] In response to such a request, a phase difference control device is provided in addition to a display device that displays an image, and the viewing angle characteristics are changed by controlling the voltage applied to the phase difference control device. A technique has been proposed (for example, Japanese Patent No. 3322197). Japanese Patent No. 3322197 exemplifies chiral nematic liquid crystal, homogeneous liquid crystal, randomly aligned nematic liquid crystal and the like as the liquid crystal mode used in the liquid crystal display device for phase difference control.

[0004] Further, a viewing angle control liquid crystal panel is provided above the display liquid crystal panel, and these panels are sandwiched between two polarizing plates to adjust the voltage applied to the viewing angle control liquid crystal panel. Thus, a configuration for performing viewing angle control is also disclosed conventionally (for example, Japanese Patent Laid-Open No. 10-268251). In JP-A-10-268251, the liquid crystal mode of the viewing angle control liquid crystal panel is a twisted nematic system.

Disclosure of the invention

Problems to be solved by the invention

[0005] In the above-mentioned Japanese Patent No. 3322197, it is stated that it is possible to switch between a wide viewing angle and a narrow viewing angle by using a liquid crystal element for phase difference control, but the effect is sufficient. I can not say. For example, FIG. 6 of Japanese Patent No. 3322197 shows an iso-contrast curve with a contrast ratio of 10: 1, and the contrast in the wide viewing angle direction certainly decreases at a narrow viewing angle. However, with this level of change, the display is sufficiently visible from the person next to you. In general, even if the contrast ratio is reduced to 2: 1, the display can be sufficiently visually recognized.

[0006] Also, the technique of Japanese Patent Laid-Open No. 10-268251 also switches between a wide viewing angle and a narrow viewing angle by adjusting the contrast by changing the voltage applied to the viewing angle control liquid crystal panel. The effect is not sufficient.

[0007] That is, both the techniques of Japanese Patent No. 3322197 and Japanese Patent Laid-Open No. 10-268251 disclose a technique for switching between a wide viewing angle and a narrow viewing angle by reducing the contrast in the wide viewing angle direction. Although this method is adopted, there is a problem that images may be seen by others who are not sufficiently shielded in the wide viewing angle direction when the viewing angle is narrow.

[0008] Therefore, the present invention has been made to solve the above problems, and a display that can be adapted to various usage environments and applications by switching between a wide viewing angle and a narrow viewing angle, and An object of the present invention is to provide a viewing angle control device used in

Means for solving the problem

[0009] In order to achieve the above object, a display according to the present invention is disposed on at least one of a display device driven according to an image to be displayed, and a back surface and a front surface of the display device, and the display device A display angle control device for controlling a viewing angle of the liquid crystal, wherein the viewing angle control device has a liquid crystal layer between a pair of translucent substrates. A cell and a drive circuit for applying a voltage to the liquid crystal layer, the liquid crystal cell is located between two polarizing plates arranged in the display, and the liquid crystal cell is the pair of translucent light Each of the substrates has a translucent electrode film and an alignment film that has not been subjected to surface patterning, and the liquid crystal layer of the liquid crystal cell is formed on at least one of the pair of translucent substrates. The alignment direction is regulated by the structure, and the drive circuit provides a first viewing angle range by changing the alignment state of the liquid crystal molecules in the liquid crystal layer of the viewing angle control device. And a second state that provides a second viewing angle range that is within the first viewing angle range and is narrower than the first viewing angle range. Features.

According to the above configuration, the alignment direction of the liquid crystal layer of the viewing angle control device is regulated by a structure formed on at least one of the pair of translucent substrates, and the alignment film is rubbed. The surface patterning process is not done. For example, when the rubbing treatment is performed, the fibers of the rubbing cloth may remain in the liquid crystal layer and cause alignment failure. S According to the above configuration, the rubbing treatment is unnecessary, and thus such a problem occurs. Absent. In the above configuration, the viewing angle control device and the two polarizing plates do not necessarily need to be adjacent to each other, and some component may be interposed between them. In the above configuration, a predetermined voltage is applied to the liquid crystal layer to change the alignment state of the liquid crystal molecules, and the polarization state of the light emitted from the liquid crystal cell force of the viewing angle control device is changed by utilizing the birefringence of the liquid crystal. Then, the polarizing plate placed on the viewer side of the viewing angle control device works as an analyzer, and the light emitted from the viewing angle control device to the viewer side is transmitted or shielded depending on the viewing angle. The power to do S. That is, the display state includes the first state (wide viewing angle) that provides the first viewing angle range, and the second viewing angle range that is within the first viewing angle range and is narrower than the first viewing angle range. Can be switched to one of the second states (narrow viewing angle). “Wide viewing angle” and “narrow viewing angle” mean a relatively wide viewing angle and a relatively narrow viewing angle rather than a specific absolute angle range. Further, in the above configuration, by using a liquid crystal cell in which liquid crystal molecules are vertically aligned, it is possible to realize a narrow viewing angle state in which a display can be visually recognized with only a limited viewing angle. As a result, it is possible to transmit light and reduce the contrast of the display on the wide viewing angle side as in the conventional viewing angle control technique. Viewing angle control can be performed by switching the shielding. As a result, it is possible to provide a display that can be adapted to various usage environments and applications.

[0011] In the above-described display, the liquid crystal cell includes a vertically aligned nematic liquid crystal layer, and the liquid crystal molecules of the liquid crystal layer are substantially perpendicular to the polarization transmission axes of the two polarizing plates. It is preferable to have a liquid crystal alignment vector orientation direction having azimuth at an angle or an arbitrary angle between approximately parallel and approximately perpendicular.

[0012] In the display described above, the structure is preferably a rib formed on at least one of the pair of translucent substrates. Furthermore, the rib is formed on both of the pair of translucent substrates, and one inclined surface of the rib formed on one of the translucent substrates is one inclined surface of the rib formed on the other translucent substrate. It is preferable to face each other.

[0013] In the display described above, the structure is preferably formed of a light-transmitting resin. This is because it can be easily processed into an arbitrary shape.

[0014] In the above display, it is preferable that at least one of the pair of translucent substrates is locally provided with a region where the translucent electrode film does not exist. Further, the structure is formed only on one of the pair of translucent substrates, and the translucent electrode film is present at a position facing the structure on the other of the pair of translucent substrates. A configuration in which a region that does not exist may be provided. It is also preferable that a region force character or graphic pattern in which the translucent electrode film does not exist is formed. Thus, when viewed from a wide viewing angle direction at a narrow viewing angle, a character or a graphic pattern is visually recognized.

[0015] In the display described above, it is preferable that the arrangement state of the structures is locally different in at least one of the pair of translucent substrates. As a result, the display state of the display surface of the display can be locally switched between the first state and the second state.

[0016] In the above display, the two polarizing plates may be arranged so that their polarization transmission axes intersect each other in the range of 80 ° to 100 °. In the above display, the two polarizing plates may be arranged so that their polarization transmission axes are substantially parallel to each other.

[0017] In the above display, the display device is a display device that emits linearly polarized light. In some cases, it is preferable that one of the two polarizing plates is a polarizing plate provided in the display device. According to this configuration, since the polarizing plate provided in the display device can be used as a polarizing plate for the viewing angle control device, the number of polarizing plates can be reduced.

[0018] The display may be configured such that the display device is a transmissive liquid crystal display device and further includes a backlight. In this case, the viewing angle control device may be disposed between the backlight and the transmissive liquid crystal display device, or may be disposed in front of the transmissive liquid crystal display device. ,.

In the display described above, the display device may be a reflective liquid crystal display device or a transflective liquid crystal display device.

[0020] Further, in the above display, the display device is a self-luminous display device, and of the two polarizing plates:! Of the self-luminous display device and the viewing angle control device It is good also as a structure provided in between.

[0021] In the above display, the polarization transmission axis of the polarizing plate intersects the alignment axis of the liquid crystal molecules viewed from the normal direction of the viewing angle control device in a range of 40 ° to 50 °. Les, which is preferably arranged so that.

[0022] In the above display, a retardation film may be provided at least at one position between the viewing angle control device and the two polarizing plates.

[0023] In the above display, it is preferable that the drive circuit switches a display state between the first state and the second state in accordance with display contents of the display device.

[0024] The display further includes an optical sensor that measures the intensity of ambient light, and the drive circuit changes the display state to the second state when the output of the optical sensor falls below a predetermined threshold value. It is preferable that

[0025] In order to achieve the above object, the first viewing angle control device according to the present invention is driven according to an image to be displayed and emits linearly polarized light. A viewing angle control device, which is used for controlling the viewing angle of the display device, and includes a liquid crystal cell having a liquid crystal layer between a pair of translucent substrates, and a voltage applied to the liquid crystal layer. And a driving circuit that is disposed on the opposite side of the surface on which the linearly polarized light from the display device is incident on the liquid crystal cell and is substantially orthogonal to the plane of polarization of the linearly polarized light A polarizing plate having a polarization transmission axis, and the liquid crystal cell includes a translucent electrode film and an alignment film that is not subjected to a surface patterning treatment in each of the pair of translucent substrates, The liquid crystal layer of the liquid crystal cell has an orientation direction regulated by a structure formed on at least one of the pair of translucent substrates, and the drive circuit changes the alignment state of the liquid crystal molecules in the liquid crystal layer. Therefore, the light emission range can be switched between the first viewing angle range and the second viewing angle range that is within the first viewing angle range and is narrower than the first viewing angle range. It is characterized by.

[0026] In order to achieve the above object, the first viewing angle control device according to the present invention is disposed in front of a self-luminous display device that is driven according to an image to be displayed. A viewing angle control device used for controlling a viewing angle of an optical display device, comprising a liquid crystal cell having a liquid crystal layer between a pair of translucent substrates, and a driving circuit for applying a voltage to the liquid crystal layer And a pair of polarizing plates provided on the outside of the pair of translucent substrates so that the polarization transmission axes are substantially perpendicular to each other, and the liquid crystal cell is provided on each of the pair of translucent substrates, The liquid crystal layer of the liquid crystal cell has a direction of alignment by a structure formed on at least one of the pair of light transmissive substrates. The driving circuit is connected to the liquid crystal component of the liquid crystal layer. By changing the arrangement state, the light emission range is between the first viewing angle range and the second viewing angle range that is within the first viewing angle range and is narrower than the first viewing angle range. It is possible to switch with.

The invention's effect

[0027] As described above, according to the present invention, a display that can be adapted to various usage environments and applications by switching the display state between a wide viewing angle and a narrow viewing angle, and the viewing angle control used therefor. Device.

Brief Description of Drawings

[0028] FIG. 1 is a cross-sectional view showing a schematic configuration of a display according to an embodiment of the present invention.

[FIG. 2] FIGS. 2 (a) to 2 (c) are schematic cross-sectional views showing a detailed configuration of a liquid crystal cell provided with a liquid crystal panel for viewing angle control according to one embodiment of the present invention. 3] FIG. 3 is a schematic diagram showing the relationship between the liquid crystal cell of the viewing angle control liquid crystal panel and the upper and lower polarizing plates.

[FIG. 4] FIG. 4 is a schematic view showing the configuration of a viewing angle control liquid crystal panel that is effective in one embodiment of the present invention. (A) shows the alignment state of liquid crystal molecules at a narrow viewing angle. b) shows the alignment of the liquid crystal molecules at a wide viewing angle.

5] FIG. 5 is a schematic diagram showing the definition of the viewing angle with respect to the laminated body of the viewing angle control liquid crystal panel and the upper polarizing plate arranged in the same direction as FIGS. 4 (a) and 4 (b).

[FIG. 6] FIGS. 6 (a) to 6 (c) are diagrams showing the positional relationship between the liquid crystal molecules and the transmission axis of the polarizing plate according to the viewing angle.

7] FIG. 7 is a chart showing the luminance distribution at a narrow viewing angle of the display according to one embodiment of the present invention.

8] FIG. 8 is a chart showing the luminance distribution at the wide viewing angle of the display according to one embodiment of the present invention.

9] FIG. 9 shows a modification of the display that is effective in one embodiment of the present invention, in which a retardation film is further provided between the translucent substrate and the polarizing plate of the viewing angle control liquid crystal panel. It is a schematic diagram shown.

[FIG. 10] FIG. 10 (a) shows the refractive index ellipsoid of the liquid crystal molecules of the viewing angle control liquid crystal panel, and FIG. 10 (b) shows the refractive index ellipsoid of the retardation film. ) Is a schematic diagram showing a refractive index ellipsoid of a retardation film conventionally used for widening the viewing angle of a liquid crystal display as a comparative example.

[FIG. 11] FIG. 11 is a schematic diagram showing the relationship between the polarization transmission axis, the refractive index ellipsoid of the liquid crystal molecules, and the refractive index ellipsoid of the retardation film. (A) is from around 90 ° azimuth. (B) is the viewing angle from around 0 ° azimuth.

12] FIG. 12 is a schematic cross-sectional view showing a configuration of a modified example of the liquid crystal cell included in the viewing angle control liquid crystal panel of the present invention.

13] FIG. 13 is a schematic cross-sectional view showing the configuration of a modification of the liquid crystal cell provided in the viewing angle control liquid crystal panel of the present invention.

FIG. 14 is a diagram showing a configuration of a modification example of the liquid crystal cell provided in the liquid crystal panel for viewing angle control according to the present invention. It is a perspective view which shows composition normally.

FIG. 15 is a perspective view schematically showing a configuration of a modified example of the liquid crystal cell provided in the viewing angle control liquid crystal panel of the present invention.

FIG. 16 is a schematic diagram showing a distribution example of a light shielding region by the viewing angle control liquid crystal panel of the present invention.

FIG. 17 is a schematic diagram showing a distribution example of a light shielding region by the viewing angle control liquid crystal panel of the present invention.

FIG. 18 is a perspective view schematically showing a configuration of a modified example of the liquid crystal cell provided in the viewing angle control liquid crystal panel of the present invention.

FIG. 19 is a schematic diagram showing a distribution example of a light shielding region by the viewing angle control liquid crystal panel of the present invention.

FIG. 20 is a cross-sectional view showing a configuration of another modified example of the display that is useful for the embodiment of the present invention.

FIG. 21 is a cross-sectional view showing a configuration of still another modified example of the display that is useful for the embodiment of the present invention.

FIG. 22 is a cross-sectional view showing a configuration of still another modified example of the display that is useful for the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, for convenience of explanation, the drawings referred to below show only the main members necessary for explaining the present invention in a simplified manner among the constituent members of one embodiment of the present invention. Therefore, the display which is useful for the present invention may include arbitrary components not shown in the drawings referred to in this specification. In addition, the dimensions of the members in each drawing do not faithfully represent the actual dimensions of the constituent members, the dimensional ratios of the respective members, and the like.

[0030] FIG. 1 is a cross-sectional view showing a schematic configuration of a liquid crystal display 100 according to an embodiment of the present invention. As shown in FIG. 1, the liquid crystal display 100 includes two liquid crystal panels: a display liquid crystal panel 1 (display device) for displaying images and a viewing angle control liquid crystal panel 2 (viewing angle control device). ing. The display liquid crystal panel 1 in the present embodiment is a transmissive type, The backlight 3 is used as a light source. The viewing angle control liquid crystal panel 2 is provided between the backlight 3 and the display liquid crystal panel 1. The liquid crystal display 100 switches the liquid crystal in the viewing angle control liquid crystal panel 2 to perform a switching operation so that the image on the display liquid crystal panel 1 can be viewed in a wide viewing angle (wide viewing angle). The display state can be switched between a state in which the image is visible and a narrow viewing angle (narrow viewing angle). The narrow viewing angle is particularly suitable when it is not desirable for others to view the image on the LCD panel 1 for display, and the wide viewing angle is used for other normal use or for displaying images on the LCD panel 1 for display. It is suitable for use when seen by multiple people at the same time.

The display liquid crystal panel 1 includes a liquid crystal cell 11 in which a liquid crystal is sandwiched between a pair of translucent substrates, and polarizing plates 12 and 13 provided on the front and back of the liquid crystal cell 11. The liquid crystal mode and cell structure of the liquid crystal cell 11 are arbitrary. Further, the drive mode of the display liquid crystal panel 1 is also arbitrary. In other words, as the liquid crystal panel 1 for display, any liquid crystal panel that can display characters, images, or moving images can be used. Accordingly, the detailed structure of the display liquid crystal panel 1 is not shown in FIG. 1, and the description thereof is also omitted. In addition, the display liquid crystal panel 1 may be a panel capable of color display or a panel dedicated to monochrome display. Furthermore, any known backlight having no limitation on the configuration of the backlight 3 can be used, and therefore the detailed structure and illustration of the backlight 3 are omitted.

The viewing angle control liquid crystal panel 2 includes a liquid crystal cell 21 having a liquid crystal layer sandwiched between a pair of translucent substrates, and a polarizing plate 22 provided on the backlight 3 side of the liquid crystal cell 21. Yes. 2A to 2C are schematic cross-sectional views showing a detailed configuration of the liquid crystal cell 21. FIG. 2 (a) to (c) show the case of V (for example, 2.5V to 3.5V) when the applied voltage to the liquid crystal cell 21 is 0V.

In addition, the state of liquid crystal molecules in the case of V (for example, 5.0 V or more) is also shown.

H

[0033] As shown in FIGS. 2 (a) to (c), the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is provided with transparent substrates 21a and 21b for keeping the distance between these substrates uniform. In this configuration, the substrates are bonded via a spacer (not shown) and the liquid crystal is sandwiched between the substrates. In this embodiment, (negative type) nematic liquid crystal having negative dielectric anisotropy is used as the liquid crystal material. The retardation d′ Δη of the liquid crystal layer of the liquid crystal sensor 21 is, for example, 200 nm to 350 nm.

In other words, the liquid crystal cell 21 includes a pair of glass substrates 201a and 201b and a glass substrate 201. Translucent electrodes 202a and 202b formed of, for example, ITO (Indium Tin Oxide) or the like on each surface of a and 201b, and ribs 203a and 203b formed on the respective surfaces of translucent electrodes 202a and 202b And a self-directing film 204a, 204b. The self-directing films 204a and 204b are formed so as to cover the surfaces of the ribs 203a and 203b and the portions where the ribs 203a and 203b are not formed on the light-transmitting electrodes 202a and 202b. In the configuration shown in FIGS. 2A to 2C, the translucent electrodes 202a and 202b are formed on the entire surface of the glass substrates 201a and 201b. Further, here, an example in which glass is used as the substrate material is given, but a resin or the like may be used as the substrate material as long as it has translucency.

Note that the display liquid crystal panel 1 needs to drive the liquid crystal in a display unit (pixel unit or segment unit), and thus has a force S having an electrode structure corresponding to the display unit, and a viewing angle control. The liquid crystal panel 2 for use has no restriction on the electrode structure. For example, a uniform transparent electrode may be formed on the entire surface of the translucent substrates 21a and 21b in order to perform uniform switching over the entire display surface, or any other electrode structure may be adopted.

The alignment films 204a and 204b are vertical alignment films that vertically align the liquid crystal molecules 21c, and are not subjected to alignment treatment such as rubbing treatment or photo-alignment treatment. Instead, the ribs 203a and 203b force provided on the translucent substrates 2la and 21b act to give a pretilt angle to the liquid crystal molecules 205, respectively. A plurality of ribs 203a and 203b are provided on the surfaces of the translucent electrodes 202a and 202b, and are arranged in parallel to each other. Thereby, the liquid crystal cell 21 has a twist angle of 0. This is a so-called parallel type cell (without twist). The alignment films 204a and 204b are formed by a known method (printing method).

[0037] The rib 203a provided on the translucent substrate 21a side and the rib 203b provided on the translucent substrate 21b side are respectively shown in FIGS. 2 (a) to (c). It is preferable that the slopes of the ribs are provided at positions where they substantially face each other. The ribs 203a and 203b are isosceles triangles (almost equilateral triangles) in the cross section perpendicular to the longitudinal direction in the example shown in FIG. The cross-sectional shape of the liquid crystal molecule 21c is not limited to this, and may be any shape as long as the pretilt angle of the liquid crystal molecule 21c can be adjusted to a desired angle, and between the ribs of the translucent substrates 21a and 21b. In this embodiment, the pitch is a force of about 50 xm to 60 xm. This value is only an example, and ribs 203a, 20 3b is made of a transparent resin such as an acrylic resin, for example, and is formed into a desired pattern by, for example, a photolithography method.

[0038] According to the above configuration, the liquid crystal molecules 21c have a molecular long axis perpendicular to the alignment films 204a and 204b (vertical alignment films) of the light-transmitting substrates 21a and 21b (homeotope pick alignment). The pretilt angle is given to the liquid crystal molecules 21c by the inclined surfaces of the force ribs 203a and 203b. As shown in FIG. 2 (a), when no voltage is applied between the translucent electrodes 202a and 202b, the liquid crystal molecules 21c are inclined by a pretilt angle with respect to the substrate surfaces of the translucent substrates 21a and 21b. However, it is in a state where it is arranged 1J almost vertically. When a voltage is applied between the translucent electrodes 202a and 202b, the liquid crystal molecules 21c are aligned in a plane perpendicular to the longitudinal direction of the ribs 203a and 203b parallel to the normal line of the translucent substrates 21a and 21b ( In other words, the direction is gradually changed according to the magnitude of the applied voltage in the plane parallel to the paper surface in Figs. 2 (a) to (c). FIG. 2 (b) and FIG. 4 (a) show the state of the liquid crystal molecules 21c when the applied voltage is V (for example, 2.5 V to 3.5 V). And mark

When the applied voltage reaches a predetermined value V (for example, 5.0 V or more), the liquid crystal molecules 21c are shown in FIG.

H

As shown in 4 (b), the molecular long axes are arranged in a state substantially parallel to the substrate surfaces of the translucent substrates 21a and 21b and substantially perpendicular to the longitudinal direction of the ribs 203a and 203b.

Here, the detailed configuration and operation of the viewing angle control liquid crystal panel 2 will be described with reference to FIG. 3 and FIGS. 4 (a) and 4 (b). FIG. 3 is a schematic diagram showing the relationship between the liquid crystal cell 21 and the upper and lower polarizing plates 13 and 22 of the viewing angle control liquid crystal panel 2. Fig. 4 is a schematic diagram mainly showing the configuration of the viewing angle control liquid crystal panel 2. (a) shows the alignment state of the liquid crystal molecules at a narrow viewing angle, and (b) shows the liquid crystal molecules at a wide viewing angle. Indicates the array status.

[0040] As shown in Fig. 3 and Fig. 4 (a) and (b), in the liquid crystal display 100 of the present embodiment, the liquid crystal cell 21 includes two polarizing plates 13, which are arranged substantially in crossed Nicols. Between the two. The polarization transmission axis X of polarizing plate 22 and the polarization transmission axis X of polarizing plate 13

If the 22 13 angle is in the range of 80 ° to 100 °, a sufficient effect of switching the viewing angle can be obtained. In addition, other components (such as a retardation film) may be disposed between the polarizing plate 13 and the liquid crystal cell 21 or between the liquid crystal cell 21 and the polarizing plate 22 as necessary.

[0041] As shown in FIGS. 3 and 4 (a) and (b), in the viewing angle control liquid crystal panel 2, The liquid crystal cell 21 and the polarizing plate 22 are inclined with respect to the longitudinal direction of the ribs 203a and 203b of the liquid crystal cell 21 with a polarization transmission axis X force of ¾0 ° to 50 ° (preferably 45 °). Arranged

twenty two

Placed. In addition, the polarizing plate 13 of the liquid crystal panel 1 for display has the polarization transmission axis X force S of the polarizing plate 13.

13 ί Night crystal Senore 21 ribs 203a, 203b are arranged in such a way that it has an inclination in the longitudinal direction (40 ° to 50 ° (preferably f 45 °)).

Here, referring to FIGS. 5 and 6 in addition to FIG. 4 described above, the viewing angle control liquid crystal panel 2 according to the above-described configuration is used to change the viewing angle into a wide viewing angle and a narrow viewing angle. The principle of switching between the two will be explained. The viewing angle control liquid crystal panel 2 operates in cooperation with the polarizing plate 13 of the display liquid crystal panel 1 by switching the voltage applied to the liquid crystal cell 21 to change the viewing angle between a wide viewing angle and a narrow viewing angle. Switch.

In the following description, the viewing angle from a certain viewpoint with respect to the laminate of the viewing angle control liquid crystal panel 2 and the polarizing plate 13 is defined as the azimuth angle Θ and polar angle with respect to the center of the polarizing plate 13. Represented by Φ. Fig. 5 shows the viewing angles from three viewpoints P to P for the viewing angle control liquid crystal panel 2 and polarizing plate 13 arranged in the same direction as Figs. 4 (a) and (b).

13

It is a thing. As shown in FIG. 5, the azimuth angle Θ is a rotation angle of a line connecting the leg of the perpendicular line dropped from the viewpoint to the plane including the surface of the polarizing plate 13 and the center 13c of the polarizing plate 13. In the example of Fig. 5, the azimuth angle Θ is the normal direction of the polarizing plate 13 with the azimuth angle in the direction of the viewpoint P being 0 °.

1

It shall increase clockwise when viewed from the side. In the example of Figure 5, the viewpoint! ³ azimuth angle Θ

2 is 90 °, and the azimuth of viewpoint P is 180 °. Polar angle φ is center 13c of polarizing plate 13 and viewpoint

twenty three

Is the angle formed by the normal line of the polarizing plate 13.

Here, referring to FIGS. 6 (a) to (c), depending on the voltage V applied to the liquid crystal cell 21, as shown in FIG. 4 (a), the molecular long axis of the liquid crystal molecules 21c is translucent. Viewing angle power of each of viewpoints P to P shown in Fig. 5 when tilted by a slight angle with respect to the normal of substrates 21a and 21b

13

The observed display state will be described.

First, for the viewing angle from the viewpoint P shown in FIG. 5 (azimuth angle Θ = 0 °), it is shown in FIG. 6 (a).

1 1

Thus, the short axis side of the liquid crystal molecules 21c is in a state facing the viewing angle direction. As a result, for the viewing angle of the viewpoint P, the liquid crystal cell 2 is emitted from the knocklight 3 and transmitted through the polarizing plate 22.

1

The linearly polarized light incident on 1 is not given birefringence by the liquid crystal molecules 21c, and the polarizing plate 13 It is shielded with. Therefore, for the viewing angle of the viewpoint P force (azimuth angle θ = 0 °), black display and

1 1

Become. In addition, when the applied voltage V to the liquid crystal cell 21 is about 2.5V 3.5V as described above, for the azimuth angle Θ = 0 °, the polar angle φ is approximately 30 ° ≤ φ 90 °

1

In this range, a light-shielding state sufficient to prevent other people from seeing it is obtained (see Figure 7). In addition, as shown in FIG. 7, L to: L f, luminance power 50cd / ml 100cd / m ² 150cd / m ² 20

1 8

Ocd / m ² 250 cd / m ² 300 cd / m ² 350 cd / m ² 400 cd / m ^{2 is} an equipotential line showing the visual angle distribution.

[0046] For the viewing angle of the viewpoint P force shown in Fig. 5 (azimuth angle Θ = 90 °), Fig. 6 (b)

twenty two

Thus, the molecular long axis of the liquid crystal molecule 21c is the polarization transmission axis X of the polarizing plate 13 and the polarizing plate 22

13

It is in a slightly tilted state with respect to each of the polarization transmission axes X. This allows viewpoint P

For the viewing angle of 22 2, linearly polarized light that is emitted from the backlight 3, passes through the polarizing plate 22 and enters the liquid crystal cell 21 has a slight birefringence caused by the liquid crystal molecules 21 c. Shielded with 13. Therefore, for the viewing angle of ³ forces (azimuth angle Θ = 0 °)

twenty two

Black display. Also, the position facing the viewpoint! ³ , that is, the azimuth angle Θ force ¾70 °,

2

Based on the same principle as when observing viewpoint P-power, the display is black. For the liquid crystal cell 21

2

When the applied voltage V is about 2.5V and 3.5V as described above, the azimuth angle Θ = 90 ° and 270 ° is about 30 ° ≤ φ <90 ° with respect to the polar angle φ. Sufficient shading can be obtained to prevent prejudice (see Fig. 7).

[0047] For the viewing angle (azimuth angle Θ = 180 °) of viewpoint P force shown in Fig. 5, Fig. 6 (c) shows.

3 3

13

The major axis side of the liquid crystal molecule 21c

twenty two

It will be in the state which opposes a viewing angle direction. As a result, for the viewing angle of viewpoint P,

Three

The linearly polarized light emitted from the light beam 3 and transmitted through the polarizing plate 22 and enters the liquid crystal cell 21 is given birefringence by the liquid crystal molecules 21c, and the polarization direction is rotated so as to coincide with the polarizing transmission axis of the polarizing plate 13. Then, the light passes through the polarizing plate 13. Therefore, it is good for the viewing angle of the viewpoint P force.

Three

A good display is obtained. When the applied voltage V is about 2.5V and 3.5V as described above, the azimuth angle Θ = 180. Is about 0 ° ≤ <90 ° for polar angle φ

Three

A good display is obtained in the box (see Figure 7). [0048] As described above, when a voltage V is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 to incline the molecular long axis of the liquid crystal molecules 21c by a slight angle with respect to the substrate normal, the azimuth angle is around 180 °. Good display can be obtained only in a narrow viewing angle range, and for other azimuth angles, the polarized light in the liquid crystal cell 21 is shielded by the polarizing plate 13 and black display is obtained. Therefore, by applying the voltage V to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2, the light emitted from the backlight 3 can be shielded in the wide viewing angle direction. That is, the display image of the display liquid crystal panel 1 cannot be viewed from the wide viewing angle direction, and the liquid crystal display 100 can be set to a narrow viewing angle.

On the other hand, when a voltage V is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 as shown in FIG. 4 (b), the molecular long axis of the liquid crystal molecule 21c is substantially parallel to the substrate. Shown in Figure 5

H

A good display in all directions can be obtained for any viewing angle P P

13

Such sufficient birefringence causes the liquid crystal display 100 to have a wide viewing angle (see FIG. 8). In FIG. 8, LL has a luminance of 130 cd / m ² 240 cd /

8

m ² 350cd / m ² 460cd / m ²

It is an equipotential line showing the distribution of viewing angles of 680 cd / m ² 790 cd / m ² 900 cd / m ² .

[0050] As described above, in the liquid crystal display 100 according to the present embodiment, the voltage applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is switched in at least two stages of V and V.

H

As a result, the display state of the liquid crystal display 100 can be switched between a wide viewing angle and a narrow viewing angle.

Note that, as shown in FIG. 9, it is preferable that the phase difference film 4 is further provided between the light-transmitting substrate 21 a and the polarizing plate 22 of the liquid crystal cell 21. When the viewing angle is narrowed by applying voltage V to the liquid crystal cell 21, it is viewed from a viewing angle other than the azimuth angle of 180 ° shown in Fig. 5 (eg, azimuth angle of 0 °, 90 °, 270 °). In this case, the linearly polarized light emitted from the backlight 3 and transmitted through the polarizing plate 22 becomes elliptically polarized light due to birefringence in the liquid crystal layer of the liquid crystal cell 21 due to the refractive index (η, n) of the liquid crystal molecules 21c. . As a result, a component that passes through the polarizing plate 13 is generated, which causes light leakage. The retardation film 4 is provided for optically compensating the elliptically polarized light. In other words, at a narrow viewing angle, a phase difference film that generates elliptically polarized light that cancels the elliptically polarized light generated in the liquid crystal layer of the liquid crystal cell 21. Nolem is used as the retardation film 4. As shown in FIG. 9, the three-dimensional refractive index axes N 1, N 2 and N of the retardation film 4 are defined. That is, N is the polarization transmission axis of the polarizing plate 13

A component perpendicular to X, N is a component parallel to the polarization transmission axis X of polarizing plate 13, N is a polarizing plate 1

13 13

The component is parallel to the normal of 3.

FIG. 10 (a) is a refractive index ellipsoid of the liquid crystal molecules 21c of the liquid crystal cell 21, where n> n.

e o

FIG. 10 (b) shows a refractive index ellipsoid of the retardation film 4, where N> N> N. Also figure

10 (c) is shown as a comparative example, which is a refractive index ellipsoid of a retardation film (negative A plate film) conventionally used for wide viewing angle of liquid crystal displays, and N = N > N.

[0053] FIG. 11 (a) shows a polarizing plate 1 when viewed from the viewpoint P (azimuth angle Θ = 90 °) shown in FIG.

2

Polarized transmission axes X and X of 3, 22 and refractive index ellipsoid F of liquid crystal molecule 21c and retardation film

13 22 21

FIG. 4 is a schematic diagram showing a relationship with a refractive index ellipsoid F of 4. Figure 11 (a) shows the bending of liquid crystal molecule 21c.

Four

N, n of the refractive index ellipsoid F, the component n parallel to the polarization transmission axis X of the polarizing plate 13, and the polarizing plate

21 e 13 xl3

It is broken down into 22 components n parallel to the polarization transmission axis X. In addition, retardation film 4

22 x22

N and N of refractive index ellipsoid F are combined with component N parallel to polarization transmission axis X of polarizing plate 13 and polarized light.

4 13 Decomposed into a component N parallel to the polarization transmission axis X of the xl3 plate 22. As can be seen from Fig. 11 (a)

22 x22

N and N are almost equal in size, and n and N are almost equal in size. Therefore, Figure 5 xl3 xl3 x22 x22

For the viewing angle near the viewpoint P (azimuth angle Θ = 90 °) shown in Fig.

2

The phase difference to be canceled is canceled out by the phase difference film 4, and light leakage can be prevented. Even when viewed from a viewing angle around azimuth Θ = 270 °, light leakage is prevented by the same principle as above.

[0054] Fig. 11 (b) shows the polarization when viewed from the viewpoint P (azimuth angle Θ = 0 °) shown in Fig. 5.

1

The polarization transmission axes X and X of the plates 13 and 22, the refractive index ellipsoid F of the liquid crystal molecule 21c, and the retardation film

13 22 21

FIG. 6 is a schematic diagram showing a relationship between a refractive index ellipsoid F of Rum 4 and FIG. As shown in Fig. 11 (b)

Four

When viewed from a viewing angle near the angle Θ = 0 °, there is almost no phase difference and no light leakage occurs.

[0055] MLC_6609 (trade name) manufactured by Merck Co., Ltd. is used as the liquid crystal material of the liquid crystal panel 2 for controlling the viewing angle according to the present embodiment, and the applied voltage V at a narrow viewing angle is 2.5 V to 3. 5V When the applied voltage V at a wide viewing angle is 5.0 V or more, the retardation film 4 is an example.

H

For example, a film with A nd = 140 nm and N = 0.1 can be used.

In FIG. 9, the force phase difference film 4 exemplifying a configuration in which the phase difference film 4 is provided between the light transmissive substrate 21 a of the liquid crystal cell 21 and the polarizing plate 13 is shown in FIG. Even if it is disposed between the optical substrate 21b and the polarizing plate 22, the same effect can be obtained.

[0057] In addition, a phase difference is obtained by combining two sheets both between the translucent substrate 21a and the polarizing plate 13 of the liquid crystal cell 21 and between the translucent substrate 21b and the polarizing plate 22 of the liquid crystal cell 21. Two retardation films having an optical compensation effect equivalent to that of film 4 may be arranged. With this configuration, the same effect as the configuration shown in FIG. 9 can be obtained.

In the above description, a configuration in which the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is provided with ribs on both the translucent substrates 21a and 21b is illustrated. However, as shown in FIG. 12, when a sufficient pretilt angle can be provided by providing a rib only on one of the translucent substrates 21a and 21b (21b side in the example of FIG. 12), the other transparent substrate The ribs on the optical substrate may be omitted.

[0059] Further, as shown in FIG. 13, in a translucent substrate (21a in this case) provided with no ribs, a region where the translucent electrode 202a does not exist is locally located at a position almost opposite to the ribs. It is also preferable to provide them. That is, in the configuration of FIG. 13, in the translucent electrode 2002a of the translucent substrate 21a, a slit is provided at a position facing the rib 202b of the translucent substrate 21b. Such a slit can be easily formed by applying an electrode material (for example, ITO) of the translucent electrode 202a on the glass substrate 2 Ola and then performing a photolithographic process using a mask corresponding to the slit shape. Can be formed. As shown in FIG. 13, when a voltage is applied to the liquid crystal cell 21 by locally providing a region where the translucent electrode does not exist in a portion facing the rib, the upper and lower translucent substrates 21a and 21b are arranged. The electric field generated in the liquid crystal is inclined with respect to the liquid crystal layer. Accordingly, in the configuration of FIG. 13, the pretilt angle of the liquid crystal molecules 21c is determined by the interaction between the rib 203b on the light transmitting substrate 21b side and the oblique electric field.

In addition, as an application example of the configuration described above in the present embodiment, as shown in FIG. 14, the surfaces of the light-transmitting substrates 21a and 21b are divided into a plurality of local regions (in this example, 21a to 21a. 21b ~ 2

1 6 1 lb ···) and ribs 203a to 203a in local regions adjacent to each other 203b ˜203b... May be configured so that the longitudinal directions thereof are orthogonal to each other. As a result, the liquid crystal cell 21

1 6

In the liquid crystal layer, regions where the alignment directions of the liquid crystal molecules 21c are different from each other are formed corresponding to the local regions. That is, when the alignment process is performed by the rubbing process, it is impossible to locally change the alignment direction, but when the alignment direction is regulated by a structure (rib) as in the present embodiment, the liquid crystal In the liquid crystal layer of the cell 21, the alignment direction of the liquid crystal molecules 21c can be locally varied.

According to the configuration shown in FIG. 14, as shown in FIG. 15, the directions in which the liquid crystal molecules 21 c rotate when a voltage is applied are orthogonal between adjacent local regions. Therefore, as shown in FIG. 15, on the front and back of the liquid crystal cell 21, the polarizing plates 13 and 22 are connected so that the polarization transmission axis X and the polarization transmission axis X are parallel.

13 22 If the voltage applied to the liquid crystal cell 21 is V, as shown in FIG.

When viewed from the wide viewing angle direction, the distribution of areas that are shielded from light and areas that are not shielded is the checkerboard pattern. As a result, when viewing from a wide viewing angle direction, when viewing from a wide viewing angle direction, about half of the display area of the image on the liquid crystal panel for display 1 is shaded to become black, and a display state that is difficult to see by other people can be realized. . Note that FIGS. 14 to 16 show examples in which the liquid crystal cells 21 are equally divided. However, depending on the division ratio, for example, a visually illusion pattern as shown in FIG. It is also possible to form the light shielding region of this pattern at a narrow viewing angle.

Further, as an application example of the configuration shown in FIG. 13, as shown in FIG. 18, the surface area of the translucent substrate 21b is changed to a plurality of local areas (in this example, 21b to 21b...). Split and adjoin each other

1 6

The longitudinal directions of the ribs 203b to 203b in the local region may be orthogonal to each other.

1 6

In this case, as shown in FIG. 18, the slit S21 may be formed on the translucent electrode 202a on the translucent substrate 21a side so as to substantially match the boundary pattern of the local regions 2la to 21a. Good. Figure

1 6

Even with the configuration shown in FIG. 18, by arranging the polarizing plates 13 and 22 in the same direction as in FIG. 15, as shown in FIG. 16, a region that is shielded from light and a region that is not shielded when viewed from the wide viewing angle direction. This is a checkerboard pattern.

[0063] As a further application example, if the slits of the translucent electrode 202a on the translucent substrate 21a side are, for example, arbitrary character or symbol patterns as shown in FIG. Sometimes, when viewed from a wide viewing angle direction, images other than the pattern shown in Fig. 19 are shielded from light. It is possible to realize a display state in which the surface is visually recognized and is not easily seen by others.

FIG. 20 shows a configuration of a liquid crystal display 200 as a modified example of the liquid crystal display 100 that works on the present embodiment. As can be seen from a comparison between FIG. 1 and FIG. 20, the stacking order of the display liquid crystal panel 1 and the viewing angle control liquid crystal panel 2 is reversed between the liquid crystal display 100 and the liquid crystal display 200. . That is, as shown in FIG. 20, the liquid crystal display 200 has a configuration in which the display liquid crystal panel 1 is laminated on the backlight 3, and the viewing angle control liquid crystal panel 2 is further laminated thereon. Note that the liquid crystal display 1 may be a transflective liquid crystal panel.

In the liquid crystal display 200, a laminate of the upper polarizing plate 12 of the display liquid crystal panel 1 and the viewing angle control liquid crystal panel 2 (the liquid crystal cell 21 and the polarizing plate 22) is illustrated with respect to the liquid crystal display 100. 4 Functions in the same manner as the laminate shown in (a) and (b). Accordingly, in the liquid crystal display 200 shown in FIG. 20, as in the liquid crystal display 100, the voltage applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is at least in two stages of V and V.

H

By switching, the display state of the liquid crystal display 100 can be switched between a wide viewing angle and a narrow viewing angle.

[0066] As described above, according to the liquid crystal displays 100 and 200 according to the present embodiment, if the voltage V is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2, as shown in FIG. It is possible to realize a display with a narrow viewing angle in which the display can be viewed only from the viewing angle. If a voltage V is applied to the liquid crystal cell 21 of the liquid crystal panel 2 for controlling the viewing angle, display can be performed from a wide viewing angle.

H

Visible.

Note that this embodiment merely shows specific examples of the present invention, and there is no intention to limit the technical scope of the present invention to these specific examples. For example, in the above description, an example in which a negative nematic liquid crystal is used is shown, but a positive nematic liquid crystal may be used. When using a positive nematic liquid crystal, the behavior of the liquid crystal molecules is different from that when using a negative nematic liquid crystal. When no voltage is applied, the liquid crystal molecules are parallel to the substrate (homogeneous orientation). Liquid crystal molecules stand up against the substrate. Therefore, when a wide viewing angle is used, no voltage is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2, and a predetermined voltage is applied when the viewing angle is narrow. [0068] Further, in the above description, the configuration in which the entire liquid crystal layer of the viewing angle control liquid crystal panel 2 is uniformly controlled is illustrated. However, if the electrode structure of the liquid crystal cell 21 is made different for each local region, the operation of the liquid crystal can be controlled for each local region. This makes it possible to vary the viewing angle of the display screen for each local area.

[0069] In the above description, the example in which the viewing angle control device is disposed on the back surface or the front surface of the display device has been described. However, the configuration in which the viewing angle control device is disposed on both the back surface and the front surface of the display device is also possible. It is included in the technical scope of the present invention.

In the above description, the transmissive liquid crystal panel is given as a specific example of the display device, but the display device is not limited to this. For example, a reflective or transflective liquid crystal display panel can be used as the display device. In addition to non-light emitting display devices such as liquid crystal display panels, for example, CRT (Cathode Ray Tube), plasma display, organic EL (Electro Luminescence) element, inorganic EL element, LED (Light Emitting Diode) display, A self-luminous display device such as a fluorescent display tube, a field emission display, or a surface-conduction electron display can also be used.

FIG. 21 is a configuration example in the case where a reflective liquid crystal display panel is used as the display device. A liquid crystal display 300 shown in FIG. 21 has a configuration in which the viewing angle control liquid crystal panel 2 is disposed on the front surface (observer side) of the reflective liquid crystal display panel 30. The reflective liquid crystal display panel 30 includes a reflective liquid crystal cell 31 having a reflector (not shown) on the substrate opposite to the observer, and a polarizing plate 32 disposed on the upper surface of the reflective liquid crystal cell 31. I have. Since the structure and operation of the reflective liquid crystal cell are well known, detailed description thereof is omitted here. In the liquid crystal display 300, a laminated body of the polarizing plate 32 of the reflective liquid crystal display panel 30 and the viewing angle control liquid crystal panel 2 (the liquid crystal cell 21 and the polarizing plate 22) is shown in FIG. It functions in the same manner as the laminate shown in (b). Accordingly, even in the liquid crystal display 300 shown in FIG. 21, as in the liquid crystal display 100, the voltage applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is switched to at least two steps of V and V. LCD

H L

The display state of Isplay 300 can be switched between a wide viewing angle and a narrow viewing angle.

FIG. 22 shows a case where a self-luminous display device such as an EL element is used as the display device. This is an example of the configuration. The display 400 shown in FIG. 22 has a configuration in which the viewing angle control liquid crystal panel 2 is arranged on the front surface (observer side) of the self-luminous display device 40. In this case, the viewing angle control liquid crystal panel 2 includes a pair of polarizing plates 22 and 23 on the front and back of the liquid crystal cell 21. The polarization transmission axes of the polarizing plates 22 and 23 are arranged so as to be substantially orthogonal to each other. In the display 400, the viewing angle control liquid crystal panel 2 (the liquid crystal cell 21 and the polarizing plates 22 and 23) functions in the same manner as the stacked body shown in FIGS. 4 (a) and 4 (b) with respect to the liquid crystal display 100. Therefore, in the display 400 shown in FIG. 22, as in the liquid crystal display 100, the voltage applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 is at least two of V and V.

H

By switching to the stage, the display state of the display 400 can be switched between a wide viewing angle and a narrow viewing angle.

[0073] In any of the above-described embodiments, when the display state of the display is a narrow viewing angle, a message, an image, an icon, or the like for informing the user is displayed on the screen of the display device. You may make it do.

In any of the above embodiments, the driving circuit of the viewing angle control device operates according to the content of the image displayed on the display device, and automatically switches between the narrow viewing angle and the wide viewing angle. You may make it change. For example, when the display is used to view web pages on the Internet, the software flag associated with each page is referred to according to the content of the web page, and it is preferable that the content is not seen by others. The display state may be automatically switched to a narrow viewing angle. Further, when the browser is activated in the encryption mode, the display state may be switched to a narrow viewing angle.

[0075] In addition, when the display power S is a part of the data input device, or is related to the data input device, the data type being input or the data type to be input is confidential. For example, the display state of the display can be adjusted to switch to a narrow viewing angle. For example, when the user inputs some personal identification number, the display may be automatically switched to the narrow viewing angle.

In any of the above embodiments, the viewing angle control device may be formed as a module or cover that can be removed from the display device. Such removable modules are electrically connected to the display when installed in the display. As a result, appropriate power and control signals can be obtained.

[0077] In any of the above-described embodiments, an optical sensor (ambient sensor) that measures the ambient light of the display is further provided, and when the measured value of the optical sensor falls below a predetermined threshold, the display on the display It is also preferable to make the state a narrow viewing angle.

[0078] It should be noted that the power of the present invention and the uses of the display and the viewing angle control device are diverse.

For example, it can be applied to displays such as notebook personal computers, personal digital assistants (PDAs), portable game consoles, mobile phones, etc. ATMs (automatic cash dispensers), information installed in public places Applies to displays for various devices such as terminals, ticket vending machines, and in-vehicle displays.

[0079] In addition, the viewing angle control device according to the present invention can be manufactured and distributed as a component of the display S as a component of the display S, which can be implemented in a state where the viewing angle control device is incorporated. There is also sex.

Industrial application fields

[0080] The present invention is industrially applicable as a display that can be adapted to various usage environments and applications by switching between a wide viewing angle and a narrow viewing angle, and a viewing angle control device used therefor.

Claims

The scope of the claims

[1] a display device driven according to an image to be displayed;

A display that is disposed on at least one of a rear surface and a front surface of the display device and includes a viewing angle control device that controls a viewing angle of the display device,

The viewing angle control device includes a liquid crystal cell having a liquid crystal layer between a pair of translucent substrates, and a drive circuit for applying a voltage to the liquid crystal layer,

The liquid crystal cell is located between two polarizing plates disposed in the display, and the liquid crystal cell is subjected to surface patterning treatment with a translucent electrode film on each of the pair of translucent substrates. The liquid crystal layer of the liquid crystal cell has an orientation direction controlled by a structure formed on at least one of the pair of translucent substrates,

The drive circuit changes the alignment state of the liquid crystal molecules in the liquid crystal layer of the viewing angle control device, thereby changing the display state to a first state that provides a first viewing angle range, and a first viewing angle. A display that is switchable between a second state that is within the range and provides a second viewing angle range that is narrower than the first viewing angle range.

[2] The liquid crystal cell includes a vertically aligned nematic liquid crystal layer, and the liquid crystal molecules of the liquid crystal layer have an angle substantially parallel to a polarization transmission axis of the two polarizing plates, a substantially vertical angle, or an approximately The display according to claim 1, which has a liquid crystal alignment vector direction having azimuth at an arbitrary angle between parallel and substantially vertical.

[3] The display according to claim 1, wherein the structure is a rib formed on at least one of the pair of translucent substrates.

[4] The rib is formed on both of the pair of translucent substrates, and one slope of the rib formed on one translucent substrate is one of the ribs formed on the other translucent substrate. Opposite the slope

The display according to claim 3.

[5] The display according to any one of claims 1 to 4, wherein the structure is formed of a translucent resin.

[6] The method according to any one of [5] to [5] above, wherein a region where the translucent electrode film does not exist is locally provided in at least one of the pair of translucent substrates. Disp Ray.

[7] The structure is formed only on one of the pair of translucent substrates,

7. The display according to claim 6, wherein the other of the pair of translucent substrates is provided with a region or a region where the translucent electrode film does not exist at a position facing the structure.

[8] The light-transmitting electrode film does not exist, and the region forms a character or graphic pattern.

The display according to claim 6.

[9] The display according to any one of claims 1 to 8, wherein an arrangement state of the structures is locally different in at least one of the pair of translucent substrates.

[10] The display according to any one of claims 1 to 9, wherein the two polarizing plates are arranged so that their polarization transmission axes intersect each other in a range of 80 ° to: 100 °.

[11] The display according to any one of [1] to [9], wherein the two polarizing plates are arranged so that their polarization transmission axes are substantially parallel to each other.

[12] The display device is a display device that emits linearly polarized light,

One of the two polarizing plates is a polarizing plate provided in the display device.

The display according to any one of 1 to 11.

13. The display device according to claim 1, wherein the display device is a transmissive liquid crystal display device and further includes a backlight.

The display according to any one of to 12.

14. The display according to claim 13, wherein the viewing angle control device is disposed between the backlight and the transmissive liquid crystal display device.

15. The viewing angle control device is disposed on a front surface of the transmissive liquid crystal display device.

13. The display according to 13.

[16] The display according to any one of claims 1 to 12, wherein the display device is a reflective liquid crystal display device or a transflective liquid crystal display device.

[17] The display device is a self-luminous display device,

The display according to any one of claims 1 to 11, wherein: of the two polarizing plates is provided between the self-luminous display device and the viewing angle control device.

[18] The polarizing transmission axis of the polarizing plate is arranged so as to intersect with the alignment axis of the liquid crystal molecules viewed from the normal direction of the viewing angle control device in a range of 40 ° to 50 °. 1 to: 17 The display according to any one of the above.

[19] The display according to any one of [1] to [18], wherein a retardation film is provided in at least one position between the viewing angle control device and the two polarizing plates.

[20] The drive circuit according to any one of claims 1 to 19, wherein the drive circuit switches a display state between the first state and the second state in accordance with display contents of the display device. Display

[21] Further comprising an optical sensor for measuring the intensity of ambient light,

20. The display according to claim 19, wherein the drive circuit sets the display state to the second state when the output of the optical sensor falls below a predetermined threshold value.

[22] A viewing angle control device that is arranged according to an image to be displayed and is arranged on at least one of the back surface and the front surface of the display device that emits linearly polarized light and is used to control the viewing angle of the display device. There,

A liquid crystal cell having a liquid crystal layer between a pair of translucent substrates;

A drive circuit for applying a voltage to the liquid crystal layer;

A polarizing plate provided on the opposite side of the plane of incidence of linearly polarized light from the display device in the liquid crystal cell and having a polarization transmission axis substantially orthogonal to the plane of polarization of the linearly polarized light, Each of the pair of translucent substrates includes a translucent electrode film and an alignment film that has not been subjected to surface patterning treatment, and the liquid crystal layer of the liquid crystal cell includes at least one of the pair of translucent substrates. The orientation direction is regulated by the structure formed in the

The drive circuit changes the alignment state of the liquid crystal molecules in the liquid crystal layer, so that the light emission range is within the first viewing angle range and the first viewing angle range, which is different from the first viewing angle range. A viewing angle control device capable of switching between a narrower second viewing angle range.

[23] A viewing angle control device that is disposed in front of a self-luminous display device that is driven according to an image to be displayed and is used to control the viewing angle of the self-luminous display device, A liquid crystal cell having a liquid crystal layer between translucent substrates;

A drive circuit for applying a voltage to the liquid crystal layer; A pair of polarizing plates provided on the outside of the pair of translucent substrates so that the polarization transmission axes are substantially orthogonal;

The liquid crystal cell includes a translucent electrode film and an alignment film that is not subjected to surface patterning treatment in each of the pair of translucent substrates, and the liquid crystal layer of the liquid crystal cell includes the pair of translucent substrates. The orientation direction is regulated by a structure formed on at least one of the optical substrates,