WO2008001896A1

WO2008001896A1 - Display and field-of-view angle control device used for the same

Info

Publication number: WO2008001896A1
Application number: PCT/JP2007/063137
Authority: WO
Inventors: Chikanori Tsukamura; Katsuhiko Morishita; Takehiko Sakai; Tsuyoshi Okazaki; Yoshiharu Kataoka; Dai Chiba
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2006-06-30
Filing date: 2007-06-29
Publication date: 2008-01-03

Abstract

A display can be applied to various use environments and applications by switching the display state between a wide field-of-view and a narrow field-of-view. The display includes a field-of-view angle control liquid crystal panel (2) on a rear surface or a front surface of the display device. The field-of-view angle control liquid crystal panel (2) includes: a liquid crystal cell (21) having liquid crystal molecules (21c) homogeneously oriented between a pair of light transmitting substrates (21a, 21b); and a drive circuit for applying voltage to a liquid crystal layer of the liquid crystal cell (21). The liquid crystal cell (21) is arranged between two polarizing plates (13, 22) arranged so that polarization transmission axes (X13, X22) substantially orthogonally intersect each other. The drive circuit switches the display state between the wide field-of-view angle and the narrow field-of-view angle by changing the orientation state of the liquid crystal molecules (21c) of the liquid crystal layer of the field-of-view angle control liquid crystal panel (2).

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 with respect to wide viewing angles because the liquid crystal itself has a viewing angle dependency. However, depending on the usage environment, it may be more convenient for the viewing angle to be narrow 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 is narrow because it is not desirable to display the information displayed by other people 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, homogenous 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 Nos. 10-268251 and 2005-316470). In Japanese Patent Laid-Open No. 10-268251, the liquid crystal mode of the viewing angle control liquid crystal panel is a twisted nematic system. Japanese Patent Application Laid-Open No. 2005-3 16470 discloses a configuration in which a viewing angle control liquid crystal panel is provided between two polarizing plates having parallel transmission axes.

Disclosure of the invention

Problems to be solved by the invention

[0005] In 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 not sufficient. . For example, FIG. 5A of Japanese Patent No. 3322197 shows an equal 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 of the human power next to it is also fully recognized. In general, even if the contrast ratio decreases 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 Application Laid-Open No. 10-268251 provide a technique for switching between a wide viewing angle and a narrow viewing angle by reducing the contrast in the wide viewing angle direction. Adopted force This method has the problem that there is a possibility that an image of another person's power that cannot be sufficiently shielded in the wide viewing angle direction may be seen at a narrow viewing angle.

[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 a display device driven according to an image to be displayed, and at least one of a back surface and a front surface of the display device, and the display Display comprising a viewing angle control device for controlling the viewing angle of the device The viewing angle control device includes a liquid crystal cell having a liquid crystal layer in which liquid crystal molecules are homogeneously aligned between a pair of translucent substrates, and a drive circuit for applying a voltage to the liquid crystal layer, In the display, the liquid crystal cell is disposed between two polarizing plates disposed so that polarization transmission axes are substantially orthogonal to each other, and the driving circuit includes an alignment state of liquid crystal molecules in a liquid crystal layer of the viewing angle control device. By changing the display state between a first state that provides the first viewing angle range and a 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 between the second state to be provided.

[0010] According to the above configuration, the two polarizing plates whose polarization transmission axes are substantially orthogonal are arranged so as to sandwich the viewing angle control device. Note that the viewing angle control device and the two polarizing plates are not necessarily 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 of the viewing angle control device is changed by utilizing the birefringence of the liquid crystal. Then, the polarizing plate arranged on the viewer side of the viewing angle control device acts as an analyzer, and the light emitted from the viewing angle control device to the viewer side can be transmitted or shielded depending on the viewing angle. it can. That is, the display state is 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). Note that “wide viewing angle” and “narrow viewing angle” mean a relatively wide viewing angle and a relatively narrow viewing angle, not a specific absolute angle range. Further, in the above configuration, by using a liquid crystal cell in which liquid crystal molecules are homogenously aligned, it is possible to realize a narrow viewing angle state in which display can be visually recognized only in a limited viewing angle. Thus, the viewing angle can be controlled by switching between light transmission and shielding rather than reducing the display contrast on the wide viewing angle side as in the conventional viewing angle control technique. As a result, it is possible to provide a display adaptable to various usage environments and applications.

[0011] In the display according to the present invention, the liquid crystal layer of the viewing angle control device includes a positive nematic liquid crystal, and the driving circuit applies a predetermined voltage to the liquid crystal layer. It is preferable to provide a viewing angle range of.

[0012] In the display according to the present invention, each of the two polarizing plates transmits each polarized light. It is preferable that the axes are arranged so as to intersect within a range of 80 ° to 100 °.

[0013] In the display according to the present invention, the display device is a display device that emits linearly polarized light, and one of the two polarizing plates is provided in the display device. A polarizing plate is preferred. For example, the display device may be a transmissive liquid crystal display device and may further include 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. Alternatively, the display device is preferably a reflective liquid crystal display device or a transflective liquid crystal display device. Alternatively, the display device is a self-luminous display device, and one of the two polarizing plates has a configuration provided between the self-luminous display device and the viewing angle control device. May be. Further, the backlight is preferably a directional backlight having directivity in the normal direction.

[0014] In the display according to the present invention, the polarization transmission axis of the polarizing plate is in the range of 40 ° to 50 ° with the alignment axis of the liquid crystal molecules viewed from the normal direction of the viewing angle control device. Preferred to be arranged to cross at.

[0015] In the display according to the present invention, it is preferable that a retardation film is provided in at least one place between the viewing angle control device and the two polarizing plates. In this case, the component of the wavelength λ of the incident light to the viewing angle control device is transmitted through the viewing angle control device and the retardation film in the first state when the first viewing angle range is reached. Is given a retardation of 3 λ Ζ2 λ Ζ8, and when passing through the viewing angle control device and the retardation film in the second state, the second viewing angle range is λ Ζ2 It is preferable to be given a retardation of λ Ζ 8 and to be given a retardation of λ λ Ζ 8 outside the second viewing angle range! /.

[0016] In the display according to the present invention, the retardation of the liquid crystal layer of the viewing angle control device is preferably 700 nm to 800 nm.

[0017] In the display according to the present invention, the thickness of the liquid crystal layer of the viewing angle control device is 5.

It is preferable that it is 0 μm or more! /.

[0018] In order to achieve the above object, a first viewing angle control device according to the present invention includes: A viewing angle control device that is arranged according to an image to be displayed and is disposed on at least one of a back surface and a front surface of a display device that emits linearly polarized light and is used to control a viewing angle of the display device. A liquid crystal cell having a liquid crystal layer in which liquid crystal molecules are homogeneously aligned between the optical substrates; a drive circuit for applying a voltage to the liquid crystal layer; and a side opposite to a surface on which the linearly polarized light from the display device is incident in the liquid crystal cell And a polarizing plate having a polarization transmission axis substantially orthogonal to the plane of polarization of the linearly polarized light, and the drive circuit changes the alignment state of the liquid crystal molecules in the liquid crystal layer, thereby providing a light emission range. Can be switched between a first viewing angle range and a second viewing angle range that is within the first viewing angle range and is narrower than the first viewing angle range.

[0019] In order to achieve the above object, a second viewing angle control device according to the present invention is disposed in front of a self-luminous display device driven according to an image to be displayed, and 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 in which liquid crystal molecules are homogeneously aligned between a pair of translucent substrates; and 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 orthogonal to each other, and the driving circuit includes liquid crystal molecules of the liquid crystal layer. By changing the arrangement state, the light emission range is changed between a wide viewing angle and a narrow viewing angle.

The invention's effect

[0020] As described above, according to the present invention, the display state can be adapted to various usage environments and applications by switching the display state between the wide viewing angle and the narrow viewing angle, and the viewing angle control used therefor. Device.

Brief Description of Drawings

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

FIG. 2 is a schematic diagram showing a configuration of a viewing angle control liquid crystal panel according to an embodiment of the present invention, in which (a) shows an alignment state of liquid crystal molecules at a narrow viewing angle; (B) shows the alignment state of the liquid crystal molecules at a wide viewing angle.

FIG. 3 shows a configuration of a viewing angle control liquid crystal panel according to an embodiment of the present invention. FIG. 4A is a schematic diagram, (a) shows the alignment state of liquid crystal molecules at a narrow viewing angle, and (b) shows the alignment state of liquid crystal molecules at a wide viewing angle.

[FIG. 4] FIG. 4 is a schematic view showing the definition of viewing angle with respect to a laminate of a viewing angle control liquid crystal panel and an upper polarizing plate arranged in the same direction as in FIGS. 2 (a) and 2 (b).

[FIG. 5] FIGS. 5 (a) to 5 (c) are diagrams showing the positional relationship between liquid crystal molecules and polarizing plate transmission axes according to viewing angles.

FIG. 6 is a modification of the display according to an embodiment of the present invention, and has a configuration further including a retardation film between a light-transmitting substrate and a polarizing plate of a viewing angle control liquid crystal panel. It is a schematic diagram shown.

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

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

FIG. 9 is a chart showing a luminance distribution at a wide viewing angle of a display as a comparative example with the present invention.

FIG. 10 is a chart showing a luminance distribution at a narrow viewing angle of a display as a comparative example with the present invention.

FIG. 11 is a luminance distribution diagram of a general backlight (without a lens sheet).

FIG. 12 is a luminance distribution diagram of an example of a directional backlight in which lens sheets are stacked.

FIG. 13 is a luminance distribution diagram of another example of a directional backlight in which lens sheets are stacked.

FIG. 14 is a luminance distribution diagram of still another example of a directional backlight in which lens sheets are stacked.

[Fig.15] Fig.15 is a luminance-polarity characteristic diagram showing the luminance distribution in the horizontal direction of the backlight (azimuth angle 0 = 90 ° force to 0 = 270 °) according to the presence or absence of the lens sheet. is there.

[FIG. 16] FIG. 16 is a luminance-polar angle characteristic diagram showing the luminance distribution in the vertical direction of the backlight (azimuth angle 0 = 0 ° force is also 0 = 180 ° direction) with and without the lens sheet. . [FIG. 17] FIG. 17 shows the narrow viewing angle state when only the knocklight is changed to the directional backlight having the luminance distribution shown in FIG. 14 under the same conditions as the case of measuring the luminance distribution of FIG. 3 is a chart showing a luminance distribution of a viewing angle control liquid crystal panel in the embodiment.

FIG. 18 is a cross-sectional view showing a configuration of another modification of the display according to the embodiment of the present invention.

FIG. 19 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. 20 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, in the drawings referred to below, for the convenience of explanation, among the constituent members of one embodiment of the present invention, only the main members necessary for explaining the present invention are shown in a simplified manner. Therefore, the display which is useful for the present invention may include any constituent members as 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.

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). And The display liquid crystal panel 1 in this embodiment is a transmissive type, and a backlight 3 is used as a light source. The viewing angle control liquid crystal panel 2 is provided between the knocklight 3 and the display liquid crystal panel 1. In the liquid crystal display 100, the liquid crystal in the viewing angle control liquid crystal panel 2 is switched to perform a wide viewing angle (wide viewing angle) in which the image on the display liquid crystal panel 1 can be visually recognized. The display state can be switched between a narrow viewing angle and a state (narrow viewing angle) where the image can be viewed. 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 preferably used in cases such as when viewed 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. Further, the display liquid crystal panel 1 may be a panel capable of color display or a panel dedicated to monochrome display. Furthermore, since any known backlight with no limitation on the configuration of the knocklight 3 can be used, illustration and description of the detailed structure of the backlight 3 are also 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. The liquid crystal layer of the liquid crystal cell 21 also has a nematic liquid crystal force that is homogeneously aligned.

Here, a detailed configuration and operation of the viewing angle control liquid crystal panel 2 will be described with reference to FIGS. Fig. 2 is a schematic diagram mainly showing the configuration of the viewing angle control liquid crystal panel 2. (a) shows the arrangement of liquid crystal molecules at a narrow viewing angle, and (b) shows the liquid crystal molecules at a wide viewing angle. The arrangement state of is shown.

As shown in FIGS. 2 (a) and 2 (b), the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 includes a pair of translucent substrates 21a and 21b. Transparent electrodes (not shown) are formed on the surfaces of the translucent substrates 21a and 21b using, for example, ITO (Indium Tin Oxide). Since the liquid crystal panel 1 for display needs to drive the liquid crystal in a display unit (pixel unit or segment unit), the power viewing angle control liquid crystal panel 2 having an electrode structure corresponding to the display unit is used. The electrode structure is not limited. 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, and any other electrode structure may be adopted. .

[0028] An alignment film (not shown) for aligning liquid crystal molecules is formed on the transparent electrode. The alignment film is rubbed by a known method. In FIGS. 2 (a) and (b), the rubbing directions in the translucent substrates 21a and 21b are indicated by arrows R and R, respectively.

ab. As shown in Fig. 2 (a) and (b), the rabin for the alignment film of the translucent substrate 21a Direction R is parallel and opposite to the rubbing direction R with respect to the alignment film of the transparent substrate 21b ab

It is. That is, the liquid crystal cell 21 is a so-called parallel cell having a twist angle of 0 ° (no twist). The pretilt angle by the rubbing process is preferably about 2 ° to. If the pretilt angle is less than 2 °, the problem of alignment defects due to the reverse tilt domain of the liquid crystal molecules when a voltage is applied is likely to occur. If the pretilt angle is greater than 7 °, tilt unevenness is likely to occur.

In the present embodiment, the liquid crystal injected into the liquid crystal cell 21 is a (positive type) nematic liquid crystal having positive dielectric anisotropy, and becomes homogenous alignment by the above-described alignment treatment. That is, when no voltage is applied, the liquid crystal molecules 21c of the liquid crystal cell 21 are arranged so that the molecular major axes are substantially parallel to the substrate surfaces of the translucent substrates 21a and 21b. The light transmitting substrates 21a and 21b are arranged so that their molecular long axes are substantially perpendicular to the substrate surfaces.

FIGS. 3 (a) and 3 (b) show a b of the liquid crystal cell 21 in a cross section parallel to the rubbing directions R and R.

It is a schematic diagram which shows a liquid crystal aligning state. As shown in Fig. 3 (a), the applied voltage V (e.g. 4.5

H

With a voltage of about V), the molecular long axis of the liquid crystal molecules 21c in the Balta region of the liquid crystal layer becomes substantially perpendicular to the substrate surfaces of the translucent substrates 21a and 21b. As shown in FIG. 3 (b), when no voltage is applied, the molecular long axes of the liquid crystal molecules 21c are substantially parallel to the substrate surfaces of the translucent substrates 21a and 21b. In FIGS. 3 (a) and 3 (b), the size of the liquid crystal molecules and the like are exaggerated in order to facilitate the distribution of the behavior V of the liquid crystal molecules.

Further, as shown in FIG. 2 (a), the polarizing plate 22 provided below the liquid crystal cell 21 in the viewing angle control liquid crystal panel 2 and the polarizing plate 13 of the display liquid crystal panel 1 are respectively The polarization transmission axes X and X are arranged so as to be substantially orthogonal. Angle between polarization transmission axis X and X

22 13 22 13

In the range of 80 ° to: LOO °, a sufficient effect of switching the viewing angle can be obtained. The polarization transmission axis X of the polarizing plate 13 of the display liquid crystal panel 1 is relative to the alignment film of the translucent substrate 21a.

13

40 for the rubbing direction R. It has a slope of ~ 50 ° (preferably 45 °).

a

Here, referring to FIG. 4 and FIG. 5 in addition to FIG. 2 described above, the viewing angle control liquid crystal panel 2 that works on the above configuration is used to change the viewing angle into a wide viewing angle and a narrow viewing angle. The principle of switching between and 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 widen the viewing angle. Switch between viewing angle and narrow viewing angle.

[0033] In the following description, the viewing angle of a certain viewpoint power 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. 4 shows the viewing angles of three viewpoints P to P for the laminate of viewing angle control liquid crystal panel 2 and polarizing plate 13 arranged in the same direction as Fig. 2 (a) and (b).

13

It is a thing. As shown in FIG. 4, the azimuth angle Θ is a rotation angle of a line connecting a leg of a perpendicular line dropped from a viewpoint to a plane including the surface of the polarizing plate 13 and the center 13c of the polarizing plate 13. In the example of Fig. 4, the azimuth angle Θ is on 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 Fig. 4, the azimuth angle of viewpoint P 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 between the normal of polarizing plate 13

Here, referring to FIGS. 5A to 5C, the applied voltage V to the liquid crystal cell 21 is

H

As shown in Fig. 3 (a), when the molecular long axis of the liquid crystal molecule 21c is almost perpendicular to the substrate surfaces of the translucent substrates 21a and 21b, the observation is made from the respective viewing angles P to P shown in Fig. 4. Be done

13

The display state will be described.

[0035] First, for the viewing angle (azimuth angle Θ = 0 °) from viewpoint P shown in Fig. 4, the polar angle φ

In the range of 1 1 1 to 20 ° to 60 °, as shown in FIG. 5 (a), the short axis side of the liquid crystal molecules 21c is opposed to the viewing angle direction. This allows viewpoint P

For one viewing angle, linearly polarized light that is emitted from the backlight 3, transmitted through the polarizing plate 22, and entered into the liquid crystal cell 21 is not given birefringence by the liquid crystal molecules 21c. Shielded. Therefore, the viewing angle from viewpoint P

For 1, it is possible to obtain a light-shielding state sufficient to prevent other people from seeing.

[0036] For the viewing angle from the viewpoint P shown in Fig. 4 (azimuth angle Θ = 90 °), the polar angle φ is larger.

2 2 2 In the range of approximately 30 ° to 60 °, as shown in Fig. 5 (b), the molecular long-axis force of the liquid crystal molecule 21c, the polarization transmission axis X of the polarization plate 13, and the polarization transmission axis X of the polarization plate 22, respectively. Against

13 22

It will be in a state of leaning down. As a result, for the viewing angle of viewpoint P power,

2

The linearly polarized light that is incident on the liquid crystal cell 21 after being transmitted through the polarizing plate 22 causes a slight birefringence due to the liquid crystal molecules 21c, but is blocked by the polarizing plate 13. Therefore, viewpoint P

2 For these viewing angles, a sufficient light-shielding state can be obtained to prevent other people from seeing. Ma In addition, when the position is opposite to the viewpoint P, that is, when the azimuth angle Θ force is 270 °, the viewpoint P force

2 2 A light-shielded state can be obtained by the same principle as at the time of observation.

[0037] For the viewing angle from the viewpoint P shown in FIG. 4 (azimuth angle Θ = 180 °), the polar angle φ is 0.

3 3 2

In the range of ° ≤φ <90 °, as shown in Fig. 5 (c), the molecular long axial force of the liquid crystal molecule 21c

2

Approximately 45 for each of the polarization transmission axis X of the plate 13 and the polarization transmission axis X of the polarizing plate 22

13 22

° Inclination and the long axis side of the liquid crystal molecules 21c face the viewing angle direction. As a result, for the viewing angle of the viewpoint P force, the light is emitted from the backlight 3 and transmitted through the polarizing plate 22 to be liquid.

Three

The linearly polarized light that has entered the crystal cell 21 is given birefringence by the liquid crystal molecules 21 c, the polarization direction is rotated so as to coincide with the polarization transmission axis of the polarizing plate 13, and the polarizing plate 13 is transmitted. Therefore, sufficient transmittance can be obtained for the viewing angle of the viewpoint P force.

Three

[0038] As described above, when voltage V is applied to the liquid crystal cell 21 of the liquid crystal panel 2 for viewing angle control.

H

Good display can be obtained only in a narrow viewing angle range centered on an azimuth angle of 180 °. 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, the voltage V is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2.

H

Therefore, the emitted light from the knocklight 3 can be shielded in the wide viewing angle direction. In other words, the display image of the display liquid crystal panel 1 cannot be seen from the wide viewing angle direction, and the liquid crystal display 100 can have a narrow viewing angle.

On the other hand, as shown in FIG. 2 (b), when no voltage is applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2, any of the viewpoints P to P shown in FIG. In the viewing angle

13

On the other hand, the liquid crystal display 100 can have a wide viewing angle by generating sufficient birefringence so that a good display can be obtained in all directions.

[0040] As described above, in the liquid crystal display 100 according to the present embodiment, the display state of the liquid crystal display 100 is changed by switching the application of voltage to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2 and the non-application of Z. It is possible to switch between a wide viewing angle and a narrow viewing angle.

[0041] As shown in FIG. 6, in the liquid crystal cell 21, there is a gap between the translucent substrate 21a and the polarizing plate 13.

In addition, it is preferable that the phase difference films 4a and 4b are provided between the translucent substrate 21b and the polarizing plate 22, respectively.

[0042] The retardation film 4a disposed between the translucent substrate 21a and the polarizing plate 13 is composed of negative C It is a retardation film called a plate, and the three-dimensional refractive index axes N, N and N

The relation of = N> N holds. Further, as shown in FIG. 6, N of the retardation film 4a is perpendicular to the polarization transmission axis X of the polarizing plate 13, and N is parallel to the polarization transmission axis X of the polarizing plate 13.

13 13

, N is parallel to the normal line of the polarizing plate 13. However, since N = N, the retardation film

N in 4a is parallel to the polarization transmission axis X of polarizing plate 13, and N is the polarization transmission axis X of polarizing plate 13.

13

The retardation film 4a may be arranged so as to be perpendicular to the surface.

13

[0043] The retardation film 4b disposed between the translucent substrate 21b and the polarizing plate 22 is also a retardation film called a negative C plate, and the three-dimensional refractive index axes N 1, N 2, N 3

The relation of = N> N holds. Further, as shown in FIG. 6, N of the retardation film 4b is perpendicular to the polarization transmission axis X of the polarizing plate 22, and N is parallel to the polarization transmission axis X of the polarizing plate 22.

22 22

, N is parallel to the normal line of the polarizing plate 22. However, since N = N, the retardation film

N in 4b is parallel to the polarization transmission axis X of polarizing plate 22, and N is the polarization transmission axis X of polarizing plate 22.

twenty two

The retardation film 4b may be arranged so as to be perpendicular to.

twenty two

When a narrow viewing angle is obtained by applying a voltage V to the liquid crystal cell 21, the method shown in FIG.

H

When viewed from a viewing angle other than around 180 ° (eg, near azimuth 0 °, 90 °, 270 °), the linearly polarized light emitted from knocklight 3 and transmitted through polarizing plate 22 is the liquid crystal molecule 21c. Due to the refractive index (η, n) of the liquid crystal, birefringence occurs in the liquid crystal layer of the liquid crystal cell 21 and elliptic polarization occurs. As a result, a component that passes through the polarizing plate 13 is generated, which causes light leakage. The phase difference films 4a and 4b are provided for optically compensating the elliptically polarized light. That is, retardation films that generate elliptically polarized light that cancels elliptically polarized light generated in the liquid crystal layer of the liquid crystal cell 21 at a narrow viewing angle are used as the retardation films 4a and 4b.

[0045] The viewing angle control liquid crystal panel 2 has an overall retardation of the liquid crystal cell 21 and the retardation films 4a and 4b in a viewing angle direction where light is shielded at a narrow viewing angle (when voltage V is applied).

H

It is most preferable to satisfy the condition of λλ2 in the viewing angle direction where light is not blocked at a narrow viewing angle, and 3 λ / 2 in almost all viewing angle directions at a wide viewing angle (no voltage applied). . However, the overall retardation of the liquid crystal cell 21 and the retardation films 4a and 4b is Eji λ Ζ8 in the viewing angle direction where light is shielded at a narrow viewing angle, and in the viewing angle direction where light is not shielded at a narrow viewing angle. Is λ Ζ2 people λ Ζ8, almost all at wide viewing angle If the condition of 3λΖ2ΖλΖ8 in the viewing angle direction is satisfied, the transmittance will be slightly lower than in the most preferable case, but it will function sufficiently as a liquid crystal panel for viewing angle control. In order to satisfy this condition, the refractive index anisotropy (Δη) of the liquid crystal material of the liquid crystal cell 21, the cell thickness of the liquid crystal cell 21 (the thickness of the liquid crystal layer) d, the retardation of the retardation films 4a and 4b, and The magnitude of the voltage V applied to the liquid crystal cell 21 is determined.

H

[0046] For example, when light of λ = 550ηπι is incident on the viewing angle control liquid crystal panel 2, the viewing angle in the front direction of the panel (azimuth angle Θ = around 180 °, polar angle φ = Only about 20 ° to 30 °), and other viewing angles (for example, polar angle φ = 45 ° at azimuth angles 0 = 0 °, 90 °, and 270 °) are not visible. The following configuration example is conceivable. That is, the difference in refractive index of the liquid crystal layer when the cell thickness d of the liquid crystal cell 21 is 6.7 m and a voltage of about 4.5 V is applied to the liquid crystal cell 21 as V.

H

Assuming that the directivity Δη is 0.121, the retardation of the liquid crystal cell 21 is 80.7 nm. Therefore, in this case, the retardation value is approximately 100 ηπ as the retardation films 4a and 4b! It is preferable to use a retardation film of about 200 nm, more preferably about 150 nm.

[0047] In order for the overall retardation of the liquid crystal cell 21 and the retardation films 4a and 4b to satisfy the above-mentioned conditions, the retardation force of the liquid crystal cell 21 is preferably about 700 nm to 800 nm. As described above, the optimum retardation value at a wide viewing angle of 3 λ Ζ2 is approximately 700 ηπ! This is because the brightness is high at a wide viewing angle. Further, considering the refractive index anisotropy of the nematic liquid crystal, the liquid crystal cell 21 of the present embodiment preferably has a cell thickness d (the thickness of the liquid crystal layer) of 5 m or more. This is because when the cell thickness d is smaller than 5 / z m, it is difficult to control the viewing range at a narrow viewing angle to an appropriate range.

Here, FIG. 7 and FIG. 8 show the luminance distribution of the liquid crystal display 100 when the viewing angle control liquid crystal panel 2 including the retardation films 4a and 4b as shown in FIG. 6 is used. FIG. 7 is a chart showing the luminance distribution of the liquid crystal display 100 at a wide viewing angle, and FIG. 8 is a chart showing the luminance distribution of the liquid crystal display 100 at a narrow viewing angle. FIGS. 9 and 10 are disclosed in FIGS. 5 and 7 of JP-A-2006-64882 as a comparative example. Fig. 9 is a chart showing the luminance distribution of a liquid crystal display equipped with a viewing angle control liquid crystal panel for a wide viewing angle (Fig. 9) and a narrow viewing angle (Fig. 10).

As shown in a comparison between FIG. 8 and FIG. 10, the liquid crystal display 100 according to the present embodiment has a wide light shielding range at a narrow viewing angle. Especially for the viewing angle from the left and right sides of the panel (direction angle 90 ° or 270 °) and from the top (direction angle 0 ° direction), the light can be shielded more reliably than before. It is possible to effectively prevent snooping. In addition, as shown in FIG. 7 and FIG. 9, the liquid crystal display 100 that works with the present embodiment normally has all viewing angles when the user looks at the display, even at a wide viewing angle. Sufficient brightness is ensured.

[0050] As the retardation films 4a and 4b, retardation films satisfying the relationship of N> N> N with respect to the three-dimensional refractive index axes N, N, and N may be used instead of the negative C plate. good. Such a retardation film is available, for example, as an X plate manufactured by Nitto Denko Corporation. When X plates are used as the retardation films 4a and 4b, the slow axis N of the retardation film 4a is perpendicular to the polarization transmission axis X of the polarizing plate 13, and N is the polarizing plate 13

13

N is parallel to the normal line of the polarizing plate 13. Also, the phase difference

13

The slow axis N of the film 4b is perpendicular to the polarization transmission axis X of the polarizing plate 22, and N is the polarizing plate 22

twenty two

N is parallel to the normal line of the polarizing plate 22. In addition, the LCD

twenty two

When the retardation of layer 21 is approximately 700 nm to 800 nm, it is preferable that d (N—N) = 60 nm and d (N—N) = 130 nm, where d is the thickness of the retardation films 4a and 4b. That's right.

[0051] Furthermore, the liquid crystal display 100 that is useful in the present embodiment may use a general backlight (a backlight having a substantially average luminance distribution over the entire polar angle range) as the knocklight 3, It is preferable to use a directional backlight. A directional backlight has a luminance distribution in which the luminance in the normal direction of the display, that is, in a relatively narrow angle range centered on φ = 0 ° in the polar angle, is higher than the luminance of other parts. A backlight that can be realized by laminating one or more lens sheets on a general backlight.

Here, referring to FIG. 11 to FIG. 14, with respect to the liquid crystal display 100 which is helpful in the present embodiment. The applicable backlight characteristics will be described. FIG. 11 is a luminance distribution diagram when a general backlight (without a lens sheet) is used as the knocklight 3 instead of a directional backlight. In this case, knocklight 3 has a symmetrical luminance distribution in the horizontal direction (azimuth angle Θ = 90 ° force to Θ = 270 ° direction), but vertical direction (azimuth angle 0 = 0 to 0 = 18 0 In the direction of °), the luminance peak P is assigned with an azimuth angle of Θ = 180 ° and a polar angle of φ = 45 °.

1

Have close. In addition, the brightness peak P of knocklight 3 is set so that the frontal force is also shifted in this way.

1

The reason is that the luminance peak is located on the true plane (polar angle φ = 0 °) when two lens sheets are stacked as described later. That is, when the lens sheet is not used or when only one lens sheet is laminated, the luminance peak of the knocklight 3 is different from the position shown in FIG.

FIGS. 12 to 14 show the luminance distribution of the knocklight 3 in the case of a directional backlight using a lens sheet. FIG. 12 is a brightness distribution diagram of the knocklight 3 when a lens sheet is laminated on the light exit surface of the backlight having the brightness characteristics shown in FIG. The lens sheet is not limited to force using “BEF II 90Z50 (trade name)” manufactured by Sumitomo 3EM. In this case, as shown in FIG. 12, the luminance distribution is changed by laminating one lens sheet on the light exit surface, and the luminance peak Ρ has an azimuth angle Θ = 180 °,

2

Appears around polar angle φ = 30 °. In the horizontal direction, the polar angle is about 0 ° ≤ ≤40 °, and in the vertical direction, the polar angle is about 0 ° ≤ ≤60 °.

[0054] FIG. 13 shows a configuration in which the same lens sheet as described above is laminated on the light exit surface of the backlight having the luminance characteristics shown in FIG. 6 is a luminance distribution diagram of the backlight 3. FIG. In this case, as shown in FIG. 13, the luminance peak Ρ is the azimuth angle Θ =

Three

Appears around 180 °, polar angle φ = 15 °, and the polar angle is about 0 in the horizontal direction. In the range of ≤φ≤60 ° and the vertical angle in the range of 0 ° ≤ ≤40 ° in the vertical direction, the brightness is relatively higher than other parts.

[0055] FIG. 14 shows a knock light in the case where two lens sheets identical to the above are stacked on the light exit surface of the backlight having the luminance characteristics shown in FIG. FIG. 3 is a luminance distribution diagram. In this case, as shown in FIG. Angle θ = 180 °, polar angle φ = around 5 °), and in the horizontal direction the polar angle is in the range of about 0 ° ≤ ≤40 °, and in the vertical direction the polar angle is about 0 ° ≤ ≤40 ° In the range, the luminance is relatively higher than other portions.

[0056] Fig. 15 is a luminance-polarity characteristic diagram showing the luminance distribution in the horizontal direction of the backlight 3 (azimuth angle 0 = 90 ° force to 0 = 270 °), with or without a lens sheet. It is. FIG. 16 is a luminance-polarity characteristic diagram showing the luminance distribution of the knocklight 3 in the vertical direction (azimuth angle Θ = 0 ° force is also Θ = 180 ° direction) with and without the lens sheet. In Fig. 15, the polar angle on the azimuth angle Θ = 270 ° side from the front direction (polar angle φ = 0 °) is shown with a negative sign. In Fig. 16, the front direction (polar angle φ = 0) The polar angle on the azimuth 0 = 180 ° side from °) is shown with a negative sign.

[0057] As shown in Figs. 15 and 16, when one lens sheet is laminated, the normal direction (polar angle)

The brightness at = 0 °) is about 1.8 times that without the lens sheet (the rate of increase in brightness is about 1.60). When two lens sheets are stacked, the luminance in the normal direction is about 2.8 times that without the lens sheet (the rate of increase in luminance is about 1.95). However, since the brightness increase rate varies depending on the constituent materials and design of the entire backlight system or the overall lighting effect, the above-mentioned brightness increase rate is not always optimal.

Further, Th shown in FIGS. 15 and 16 represents a luminance equivalent to 50% of the luminance in the normal direction when one lens sheet is laminated. The polar angle range (horizontal direction) in which the luminance of Th or higher can be obtained is about 66 ° for the lens sheet arrangement shown in FIG. 12, and about 96 ° for the lens sheet arrangement shown in FIG. Similarly, the polar angle range (vertical direction) at which luminance of Th or higher can be obtained is about 99 ° for the lens sheet arrangement shown in FIG. 12, and about 66 for the lens sheet arrangement shown in FIG. °. When two lens sheets are stacked, the polar angle range that provides a luminance equivalent to 50% of the luminance in the normal direction is about 58 ° in the horizontal direction and about 88 ° in the vertical direction. is there.

[0059] FIG. 8 shows the luminance distribution when a general backlight having an almost average luminance distribution over the entire polar angle range, which is not a directional backlight, is used as the backlight 3. A certain force When only the knocklight 3 is changed to the directional backlight having the luminance distribution shown in FIG. A luminance distribution as shown in FIG. 17 is obtained. That is, as the luminance peak approaches the front direction, the range of azimuth angles in which the light is shielded becomes wider. Therefore, it is possible to realize a display device that more reliably prevents a person looking at someone else from behind.

FIG. 18 shows a configuration of a liquid crystal display 200 as a modified example of the liquid crystal display 100 that is useful for the present embodiment. As can be seen from the comparison between Fig. 1 and Fig. 18, the liquid crystal display 100 and the liquid crystal display 200 have the stacking order of the display liquid crystal panel 1 and the viewing angle control liquid crystal panel 2 reversed. ing. That is, as shown in FIG. 18, the liquid crystal display 200 has a configuration in which the display liquid crystal panel 1 is laminated on the knocklight 3, and the viewing angle control liquid crystal panel 2 is further laminated thereon. In the liquid crystal display 200, the display liquid crystal panel 1 may be a transflective liquid crystal panel.

In the liquid crystal display 200, a laminated body 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. 2 Functions in the same manner as the laminate shown in (a) and (b). Accordingly, in the liquid crystal display 200 shown in FIG. 18, as with the liquid crystal display 100, the display state of the liquid crystal display 100 can be controlled by switching ON / OFF of the voltage applied to the liquid crystal cell 21 of the liquid crystal panel 2 for controlling the viewing angle. You can switch between the angle and the wide viewing angle.

[0062] 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 liquid crystal panel 2 for viewing angle control, the liquid crystal display from a limited viewing angle can be obtained.

H

A narrow viewing angle display can be realized. Further, if a voltage is not applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2, the display can be visually recognized with a wide viewing angle force.

It should be noted 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, the above description exemplifies a configuration in which the entire liquid crystal layer of the viewing angle control liquid crystal panel 2 is uniformly controlled. However, if the electrode structure of the liquid crystal cell 21 is 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.

[0064] In the above description, the viewing angle control device is disposed on the back surface or the front surface of the display device. Although an example has been described, a configuration in which viewing angle control devices are arranged on both the back surface and the front surface of the display device is also included in the technical scope of the present invention.

Further, in the above description, the force display device using the transmissive liquid crystal panel as a specific example of 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, Self-luminous display devices such as a fluorescent display tube, a field emission display, and a surface-conduction electron-emitter display can also be used.

FIG. 19 shows 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. 19 has a configuration in which a viewing angle control liquid crystal panel 2 is arranged on the front surface (observer side) of a 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, the 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, in the liquid crystal display 300 shown in FIG. 19, similarly to the liquid crystal display 100, the display state of the liquid crystal display 300 is sandwiched by switching the applied voltage to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2. It can be switched between viewing angle and wide viewing angle.

FIG. 20 shows a configuration example in the case where a self-luminous display device such as an EL element is used as the display device. The display 400 shown in FIG. 20 has a configuration in which the viewing angle control liquid crystal panel 2 is disposed 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 Display 400, the viewing angle control liquid crystal panel 2 (liquid crystal cell 21 and polarizing plates 22, 23) The liquid crystal display 100 functions in the same manner as the laminate shown in FIGS. 2 (a) and 2 (b). Accordingly, in the display 400 shown in FIG. 20, as with the liquid crystal display 100, the display state of the display 400 can be changed by switching ON / OFF of the voltage applied to the liquid crystal cell 21 of the viewing angle control liquid crystal panel 2. And a wide viewing angle.

[0068] Even if there is a! /! Deviation in the above embodiment, 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 to that effect is displayed. You may make it display on the screen of a display apparatus.

[0069] 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.

[0070] In addition, when the display force is a part of the data input device, or when the data type being input or the data type to be input is confidential, in connection with the data input device. It is also possible to adjust the display state 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 a cover that can be removed from the display device. When such a removable module is attached to the display device, it can be electrically connected to the display device to obtain appropriate power and control signals.

[0072] In any of the above 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.

[0073] It should be noted that the display and the viewing angle control device that are useful in the present invention have a wide variety of uses. 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.

[0074] Although the viewing angle control device according to the present invention may be implemented in a state of being incorporated in a display, the viewing angle control device may be manufactured and distributed as a display component alone. There is also.

Industrial application fields

The present invention can be industrially used 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 in which liquid crystal molecules are homogenously aligned between a pair of translucent substrates, and a drive circuit for applying a voltage to the liquid crystal layer. In the display, the polarization transmission axes are arranged so as to be substantially orthogonal.

Placed between two polarizing plates,

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 layer of the viewing angle control device includes a positive nematic liquid crystal,

The display according to claim 1, wherein the drive circuit provides the second viewing angle range by applying a predetermined voltage to the liquid crystal layer.

[3] The display according to claim 1 or 2, wherein the two polarizing plates are arranged so that their polarization transmission axes intersect each other in a range of 80 ° to: LOO °.

[4] 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 3.

5. The display according to claim 4, wherein the display device is a transmissive liquid crystal display device and further includes a backlight.

6. The display according to claim 5, wherein the viewing angle control device is disposed between the backlight and the transmissive liquid crystal display device.

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

5. The display according to 5.

8. The backlight is a directional backlight having directivity in the normal direction.

~ 7 !, The display according to any one item.

[9] The display according to claim 4, wherein the display device is a reflective liquid crystal display device or a transflective liquid crystal display device.

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

4. The display according to claim 1, wherein one of the two polarizing plates is provided between the self-luminous display device and the viewing angle control device. 5.

[11] 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 °. 1-10

V, display according to one item.

[12] The display according to any one of [1] to [L1], wherein a phase difference film is provided at least at one position between the viewing angle control device and the two polarizing plates.

[13] The component of the wavelength λ of the incident light to the viewing angle control device is

When passing through the viewing angle control device and the retardation film in the first state, the first viewing angle range is given a retardation of 3λΖ2 ± λΖ8,

When passing through the viewing angle control device and the retardation film in the second state, the second viewing angle range is given a retardation of λ Ζ2 people λ Ζ8, other than the second viewing angle range. 13. A display as claimed in claim 12, wherein the display is given a retardation of λ 8.

[14] The liquid crystal layer retardation of the viewing angle control device is 700ηπ! The display according to any one of claims 1 to 13, which is ˜800 nm.

15. The display according to any one of claims 1 to 14, wherein a thickness of a liquid crystal layer of the viewing angle control device is 5.0 m or more.

[16] 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 senore having a liquid crystal layer in which liquid crystal molecules are homogeneously aligned between a pair of translucent substrates;

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

In the liquid crystal cell, the liquid crystal cell is provided on the opposite side of the surface on which the linearly polarized light from the display device is incident. And a polarizing plate having a polarization transmission axis substantially orthogonal to the plane of polarization of the linearly polarized light, and the drive circuit changes the alignment state of the liquid crystal molecules of the liquid crystal layer, thereby A viewing angle control device characterized in that it can be switched between a first viewing angle range and a second viewing angle range within the first viewing angle range and narrower than the first viewing angle range. Place.

A viewing angle control device that is disposed in front of a self-luminous display device that is driven in accordance with an image to be displayed and is used to control the viewing angle of the self-luminous display device. A liquid crystal senore having a liquid crystal layer in which liquid crystal molecules are homogeneously aligned between 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 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.