WO2020066293A1

WO2020066293A1 - Display device

Info

Publication number: WO2020066293A1
Application number: PCT/JP2019/030352
Authority: WO
Inventors: 幸次朗池田; 正章加邉
Original assignee: 株式会社ジャパンディスプレイ
Priority date: 2018-09-28
Filing date: 2019-08-01
Publication date: 2020-04-02
Also published as: JP2020052363A

Abstract

Provided is a display device that suppresses brightness reduction. This display device (1) comprises: an image display panel (30) having a plurality of pixels; a light source unit disposed on the same side of the image display panel (30) as the back surface (30s) of the image display panel (30); a light adjustment panel (80) that is disposed between the image display panel (30) and light source unit, has a lower alignment film (89) on the light source unit side thereof, a plurality of first electrodes arranged in a matrix, an upper alignment film (74) disposed further to the image display panel (30) side than the lower alignment film (89) so as to oppose the lower alignment film (89), second electrodes, and a liquid crystal layer, and is capable of transmitting light emitted by the light source unit to the back surface (30s) side of the image display panel (30) while changing the transmittance in the liquid crystal layer through the application of voltages between the first electrodes and second electrodes; and a lower polarizing plate (52) disposed between the light adjustment panel (80) and light source unit. The transmission axis of the lower polarizing plate (52) follows a direction that is not parallel with or orthogonal to the initial alignment direction of the lower alignment film (89).

Description

Display device

<< The present invention relates to a display device.

Some liquid crystal display devices irradiate an image display panel having a liquid crystal layer with light from a backlight, and display an image using light transmitted through the liquid crystal layer. Such a liquid crystal display device is required to have an improved contrast ratio. For example, Patent Document 1 describes that a contrast ratio is improved by overlapping two liquid crystal panels.

Japanese Patent No. 4878032

However, when two liquid crystal panels are superimposed, light from the backlight passes through the two liquid crystal panels, so that the amount of transmitted light is reduced and luminance may be reduced.

The present invention has been made in view of the above problems, and has as its object to provide a display device that suppresses a decrease in luminance.

A display device according to one embodiment of the present invention includes an image display panel having a plurality of pixels, a light source unit provided on a back side of the image display panel, and a light source unit provided between the image display panel and the light source unit. A lower alignment film on the light source unit side, a plurality of first electrodes arranged in a matrix, an upper alignment film provided on the image display panel side of the lower alignment film and opposed to the lower alignment film, a second electrode, And a liquid crystal layer, the light emitted from the light source unit is applied to the image by changing a transmittance in the liquid crystal layer by a voltage applied between the first electrode and the second electrode. A light control panel configured to be able to transmit on the back side of the display panel, and a lower polarizing plate provided between the light control panel and the light source unit, and the transmission axis of the lower polarizing plate is Not parallel and not perpendicular to the initial alignment direction of the lower alignment film It is along the direction.

FIG. 1 is a diagram illustrating a main configuration example of a display device according to the first embodiment. FIG. 2 is a block diagram illustrating a functional configuration example of the signal processing unit. FIG. 3 is a diagram illustrating a stacked configuration of the display device according to the first embodiment. FIG. 4 is a diagram illustrating an example of a pixel array of the image display panel. FIG. 5 is a cross-sectional view illustrating an example of a schematic cross-sectional structure of the image display panel. FIG. 6 is a diagram illustrating an example of a relationship between a display area and a display divided area. FIG. 7 is a diagram illustrating an example of a main configuration of the light source unit. FIG. 8 is a diagram illustrating an example of a main configuration of the light control unit. FIG. 9 is a cross-sectional view illustrating an example of a schematic cross-sectional structure of the light control panel. FIG. 10 is a flowchart illustrating an example of the flow of processing of the signal processing unit. FIG. 11 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to the first embodiment. FIG. 12 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the first embodiment. FIG. 13 is a graph illustrating an example of the luminance of the display device according to the first embodiment. FIG. 14 is a graph illustrating an example of the contrast of the display device according to the first embodiment. FIG. 15 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to a first modification. FIG. 16 is a diagram showing the relationship between the transmission axis direction and the initial alignment direction in the first modification. FIG. 17 is a graph illustrating an example of the luminance of the display device according to the first modification. FIG. 18 is a graph illustrating an example of the contrast of the display device according to the first modification. FIG. 19 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to the second embodiment. FIG. 20 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the second embodiment. FIG. 21 is a graph illustrating an example of the luminance of the display device according to the second embodiment. FIG. 22 is a graph illustrating an example of the contrast of the display device according to the second embodiment. FIG. 23 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to a second modification. FIG. 24 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the second modification. FIG. 25 is a graph illustrating an example of the luminance of the display device according to the second modification. FIG. 26 is a graph illustrating an example of the contrast of the display device according to the second modification. FIG. 27 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to the third embodiment. FIG. 28 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the third embodiment. FIG. 29 is a graph illustrating an example of the luminance of the display device according to the third embodiment. FIG. 30 is a graph illustrating an example of the contrast of the display device according to the third embodiment. FIG. 31 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to a third modification. FIG. 32 is a diagram showing the relationship between the transmission axis direction and the initial alignment direction in the third modification. FIG. 33 is a graph illustrating an example of the luminance of the display device according to the third modification. FIG. 34 is a graph illustrating an example of the contrast of the display device according to the third modification.

各 Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention, which are naturally included in the scope of the present invention. In addition, in order to make the description clearer, the width, thickness, shape, and the like of each part may be schematically illustrated as compared with actual embodiments, but this is merely an example, and the interpretation of the present invention is not limited thereto. It is not limited. In the specification and the drawings, components similar to those described in regard to a drawing thereinabove are marked with like reference numerals, and a detailed description is omitted as appropriate.

(1st Embodiment)
(Main configuration of display device)
FIG. 1 is a diagram illustrating a main configuration example of a display device according to the first embodiment. As shown in FIG. 1, the display device 1 according to the first embodiment includes a signal processing unit 10, a display unit 20, a light source unit 50, and a light control unit 70. The signal processing unit 10 performs various outputs based on an input signal IP input from the external control device 2. The input signal IP is a signal that functions as data for causing the display device 1 to display and output an image, and is, for example, an RGB image signal. The signal processing unit 10 outputs the output image signal OP generated based on the input signal IP to the display unit 20. Further, the signal processing unit 10 outputs the local dimming signal DI generated based on the input signal IP to the dimming unit 70. Further, when the input signal IP is input, the signal processing unit 10 outputs a light source drive signal BL for operating the light source unit 50 to the light source unit 50.

FIG. 2 is a block diagram showing a functional configuration example of the signal processing unit. The signal processing unit 10 is an integrated circuit such as an FPGA (Field-Programmable Gate Array). The signal processing unit 10 includes, for example, an image analysis unit 11, a light control unit 12, a light control buffer 13, a correction unit 14, an image buffer 15, a synchronization unit 16, and a light source control unit 17. The signal processing unit 10 performs various processes corresponding to these functions mounted on the integrated circuit based on the input signal IP.

The display unit 20 includes the image display panel 30 and the image display panel driving unit 40. The image display panel 30 is a panel having a plurality of pixels 48, and more specifically, has a display area OA in which the plurality of pixels 48 are provided. The plurality of pixels 48 are arranged, for example, in a matrix. The image display panel 30 of the first embodiment is a liquid crystal image display panel. The image display panel driving section 40 as a first signal output section has a signal output circuit 41 and a scanning circuit 42. The signal output circuit 41 drives a plurality of pixels 48 according to the output image signal OP. The scanning circuit 42 outputs a drive signal for scanning a plurality of pixels 48 arranged in a matrix in units of a predetermined row (for example, one row). The pixel 48 is driven such that a grayscale value corresponding to the output image signal OP is output at the timing when the drive signal is output.

The light source unit 50 is a light source device that emits light toward the display area OA of the image display panel 30. The light control unit 70 controls the amount of light emitted from the light source unit 50 and output through the display area OA. The light control unit 70 includes a light control panel 80 and a circuit unit 90. The light control panel 80 is disposed at a position overlapping the display area OA when the display area OA is viewed in a plan view, that is, when the display device is viewed from a Z direction described later, and is provided so as to change the light transmittance. The light control area DA is provided. The circuit unit 90 controls the light transmittance of the light control area DA.

FIG. 3 is a diagram showing a layered configuration of the display device according to the first embodiment. As shown in FIG. 3, in the display device 1 according to the first embodiment, the light source unit 50, the light control panel 80, and the image display panel 30 are superimposed in this order along the Z direction that is the superimposition direction, that is, It is laminated. Specifically, the light control panel 80 is stacked on the irradiation surface 50 s, which is the front surface (upper surface) of the light source unit 50 and the surface on which light is emitted. The image display panel 30 is stacked on the opposite side of the light source unit 50 with the light control panel 80 interposed therebetween. In other words, the light source unit 50 is provided on the back surface 30 s side opposite to the front surface 30 t of the image display panel 30, and the light control panel 80 is located between the light source unit 50 and the image display panel 30 in the Z direction. Is provided. The light emitted from the irradiation surface 50 s of the light source unit 50 in the Z direction enters the light control area DA of the light control panel 80. The light control panel 80 transmits the light incident on the light control area DA to the rear surface 30s side of the image display panel 30 so that the light transmittance, that is, the light amount can be changed. The light transmitted from the light control panel 80 enters the back surface 30s of the image display panel 30, passes through the inside of the image display panel 30, and is emitted from the front surface 30t opposite to the back surface 30s. Thus, the image display panel 30 displays and outputs an image on the front surface 30t side. As described above, the light source unit 50 functions as a backlight that illuminates the display area OA of the image display panel 30 from the back. Hereinafter, two directions orthogonal to the Z direction are defined as an X direction and a Y direction. The X direction and the Y direction are orthogonal. The plurality of pixels 48 are arranged in a matrix along the X direction and the Y direction. In the Z direction, the position of the upper polarizing plate 58 with respect to the light source unit 50 is defined as an upper side (front side), and the position of the light source unit 50 with respect to the upper polarizing plate 58 is defined as a lower side (rear side).

The image display panel 30 has an array substrate 30a and a counter substrate 30b located on the front surface 30t side (upper side) of the array substrate 30a and facing the array substrate 30a in the Z direction. As will be described later, a liquid crystal layer LC1 is disposed between the array substrate 30a and the counter substrate 30b (see FIG. 5). The light control panel 80 includes a first substrate 80a, and a second substrate 80b located on the image display panel 30 side with respect to the first substrate 80a and facing the first substrate 80a. As described later, a liquid crystal layer LC2 is arranged between the first substrate 80a and the second substrate 80b (see FIG. 9).

More specifically, as shown in FIG. 3, the display device 1 according to the first embodiment includes a light source unit 50, a lower polarizing plate 52, a dimming panel 80, a middle polarizing plate 54, an adhesive layer 56, an image display panel 30, The upper polarizing plate 58 is laminated (superposed) in this order in the Z direction. That is, the lower polarizing plate 52 is provided between the light source unit 50 and the light control panel 80, the middle polarizing plate 54 is provided between the light control panel 80 and the image display panel 30, and the upper polarizing plate 58 is provided. , Is provided on the front surface 30 t side of the image display panel 30, that is, above the image display panel 30. The lower polarizer 52, the middle polarizer 54, and the upper polarizer 58 transmit light of a component that oscillates in a predetermined direction of incident light and block light of a component that oscillates in a direction other than that direction. It is a polarizing plate.

The adhesive layer 56 is provided between the light control panel 80 and the image display panel 30, and bonds the light control panel 80 and the image display panel 30. The adhesive layer 56 is formed of a transparent member that can transmit light, and in the present embodiment, is an optical elastic resin, that is, SVR (Super View Resin). The adhesive layer 56 is provided between the middle polarizing plate 54 and the image display panel 30 in the first embodiment, but may be provided between the light control panel 80 and the image display panel 30. For example, it may be provided between the light control panel 80 and the middle polarizer 54. Further, a diffusion plate for diffusing light may be provided between the light control panel 80 and the image display panel 30, more specifically, between the middle polarizer 54 and the image display panel 30. By providing the diffusion plate, moire can be reduced.

(Image display panel)
Next, the configuration of the image display panel 30 will be described. FIG. 4 is a diagram illustrating an example of a pixel array of the image display panel. As illustrated in FIG. 4, the pixel 48 has, for example, a first sub-pixel 49R, a second sub-pixel 49G, a third sub-pixel 49B, and a fourth sub-pixel 49W. The first sub-pixel 49R displays a first primary color (for example, red). The second sub-pixel 49G displays a second primary color (for example, green). The third sub-pixel 49B displays a third primary color (for example, blue). The fourth sub-pixel 49W displays a fourth color (specifically, white). As described above, the pixels 48 arranged in a matrix on the image display panel 30 include the first sub-pixel 49R for displaying the first color, the second sub-pixel 49G for displaying the second color, and the third color. It includes a third sub-pixel 49B for displaying and a fourth sub-pixel 49W for displaying a fourth color. The first color, the second color, the third color, and the fourth color are not limited to the first primary color, the second primary color, the third primary color, and white, but may be different colors such as complementary colors. Further, the pixel 48 may not include the fourth sub-pixel 49W, but may include only three sub-pixels of the first sub-pixel 49R, the second sub-pixel 49G, and the third sub-pixel 49B. When the fourth sub-pixel 49W displaying the fourth color is irradiated with the same light source lighting amount, the first sub-pixel 49R displaying the first color, the second sub-pixel 49G displaying the second color, It is preferable that the third sub-pixel 49B that displays the third color be brighter. In the following description, when it is not necessary to distinguish the first sub-pixel 49R, the second sub-pixel 49G, the third sub-pixel 49B, and the fourth sub-pixel 49W, they are referred to as sub-pixels 49.

The display device 1 is more specifically a transmission type color liquid crystal display device. As illustrated in FIG. 4, the image display panel 30 is a color liquid crystal display panel, in which a first color filter that allows the first primary color to pass is disposed between the first sub-pixel 49R and the image observer, and a second color filter is provided. A second color filter that passes the second primary color is disposed between the sub-pixel 49G and the image observer, and a third color filter that transmits the third primary color is disposed between the third sub-pixel 49B and the image observer. Have been. In the image display panel 30, no color filter is arranged between the fourth sub-pixel 49W and the image observer. In this case, a large step occurs in the fourth sub-pixel 49W. Therefore, the fourth sub-pixel 49W may be provided with a transparent resin layer instead of the color filter. Thereby, it is possible to suppress the occurrence of a large step in the fourth sub-pixel 49W.

The signal output circuit 41 is electrically connected to the image display panel 30 by a signal line DTL. The image display panel driving unit 40 selects a sub-pixel 49 in the image display panel 30 by the scanning circuit 42 and controls a switching element (for example, a thin film transistor (TFT)) for controlling the operation (light transmittance) of the sub-pixel 49. Film (Transistor)) is turned on (ON) and off (OFF). The scanning circuit 42 is electrically connected to the image display panel 30 by a scanning line SCL. In the first embodiment, the scanning line SCL extends along the X direction and the signal line DTL extends along the Y direction. However, this is an example of the extending direction of the scanning line SCL and the signal line DTL, and is not limited thereto. However, it can be changed as appropriate.

FIG. 5 is a sectional view showing an example of a schematic sectional structure of the image display panel. As shown in FIG. 5, in the image display panel 30, the array substrate 30a and the counter substrate 30b are stacked in this order along the Z direction, and a plurality of the substrates are arranged between the array substrate 30a and the counter substrate 30b. A liquid crystal layer LC1 including the liquid crystal element LC is provided. The array substrate 30a has a substrate 21, insulating

films

22a, 22b, 22c, 22d, a switching element 24, a counter electrode 26, a pixel electrode 28, and a lower alignment film 29. The counter substrate 30b has a substrate 31 and an upper alignment film 32. The switching element 24 has a channel 24a, a source 24b, a gate 24c, and a drain 24d. Hereinafter, the laminated structure of the image display panel 30 will be described.

In the array substrate 30a, a substrate 21, an insulating film 22a, an insulating film 22b, an insulating film 22c, a counter electrode 26, an insulating film 22d, a pixel electrode 28, and a lower alignment film 29 are stacked (superimposed) in this order in the Z direction. Have been. The substrate 21 is a substrate such as a glass substrate or a film substrate. On the substrate 21, a channel 24a (island) of the switching element 24 is provided. The insulating film 22a is provided on the substrate 21 and in contact with the channel 24a. The gate 24c of the switching element 24 is provided on the insulating film 22a at a position overlapping with the channel 24a. The insulating film 22b is provided on the insulating film 22a and in contact with the gate 24c. The source 24b and the drain 24d of the switching element 24 are provided on the insulating film 22b at positions overlapping the channel 24a. Part of the source 24b and the drain 24d penetrate the insulating

films

22b and 22a and are connected to the channel 24a. The insulating film 22c is provided on the insulating film 22b and in contact with the source 24b and the drain 24d. Note that the gate 24c is disposed on the side opposite to the substrate with respect to the channel 24a, and the configuration of a so-called top gate has been described as an example, but the present invention is not limited to this. For example, the gate 24c may have a configuration of a bottom gate disposed between the channel 24a and the substrate via an insulating film. The counter electrode 26 is an electrode arranged to face the pixel electrode 28, and in the present embodiment, is a common electrode provided in the display area OA of the image display panel 30. The counter electrode 26 may be configured by a plurality of block-shaped electrodes extending in the X direction or the Y direction in the display area OA. The insulating film 22d is provided on the counter electrode 26. The pixel electrodes 28 that constitute the sub-pixels 49 are provided on the insulating film 22d, and a plurality of pixel electrodes 28 are provided in a matrix in the display area OA. Each pixel electrode 28 has a shape provided with a plurality of groove-shaped openings extending in the Y direction. In other words, a plurality of band-shaped electrodes forming comb teeth extending in the Y direction. Is provided. The insulating

films

22a, 22b, 22c, and 22d are made of, for example, an insulating member such as a silicon nitride film (SiNx). The counter electrode 26 and the pixel electrode 28 are transparent electrodes made of, for example, indium tin oxide (ITO). Further, in the present embodiment, the opposing electrode 26 is disposed between the pixel electrode 28 and the substrate 21, but is not limited to this. For example, the pixel electrode 28 may be disposed between the counter electrode 26 and the substrate 21, or the counter electrode 26 and the pixel electrode 28 may be disposed in the same layer.

The lower alignment film 29 is provided on the front surface side of the array substrate 30a, in other words, provided on the pixel electrode 28 and the insulating film 22d. That is, the lower alignment film 29 becomes the surface of the array substrate 30a on the liquid crystal layer LC1 side. In a state where no electric field (voltage) is applied between the counter electrode 26 and the pixel electrode 28, the liquid crystal element LC in the liquid crystal layer LC1 is aligned according to the initial alignment direction given to the lower alignment film 29. That is, the initial alignment direction is a direction in which the lower alignment film 29 aligns the liquid crystal element LC when no electric field (voltage) is applied between the counter electrode 26 and the pixel electrode 28. For example, by rubbing the lower alignment film 29 on the surface on the liquid crystal layer LC1 side, a plurality of grooves are formed on the surface on the liquid crystal layer LC1 side in one direction, that is, along the rubbing direction. Since the liquid crystal element LC near the lower alignment film 29 is aligned along the rubbing direction, the rubbing direction can be said to be the initial alignment direction. The lower alignment film 29 may be, for example, a rubbed film of a polyimide (PI) -based alignment film material. However, the lower alignment film 29 may be configured to be able to align the liquid crystal element LC in the initial alignment direction by a process other than rubbing. For example, the lower alignment film 29 may be a photo alignment film. Since the lower alignment film 29 is an alignment film provided on the array substrate 30a, the initial alignment direction of the lower alignment film 29 is the same as that of the array substrate 30a, that is, the back side (the side opposite to the front side) of the image display panel 30. ) Is the initial orientation direction of the substrate.

(4) In the counter substrate 30b, the upper alignment film 32 and the substrate 31 are stacked (superposed) in the Z direction in this direction. The upper alignment film 32 is the surface of the counter substrate 30b on the liquid crystal layer LC1 side. When no voltage is applied between the counter electrode 26 and the pixel electrode 28, the liquid crystal element LC in the liquid crystal layer LC1 is aligned according to the initial alignment direction given to the upper alignment film 32. The initial alignment direction of the upper alignment film 32 is parallel to the initial alignment direction of the lower alignment film 29, and more specifically, is preferably the same direction as the initial alignment direction of the lower alignment film 29. Will be described later. Like the lower alignment film 29, the upper alignment film 32 may be capable of aligning the liquid crystal element LC in the initial alignment direction by a rubbing process, or may be capable of aligning the liquid crystal element LC in the initial alignment direction by another process such as optical alignment. Orientation may be possible. The upper alignment film 32 faces the lower alignment film 29 and can be said to be an alignment film provided on the front surface 30t side (upper side) of the image display panel 30 with respect to the lower alignment film 29. Further, since the upper alignment film 32 is an alignment film provided on the counter substrate 30 b side, the initial alignment direction of the upper alignment film 32 is the counter substrate 30 b, that is, the upper (front) side of the image display panel 30. Is the initial alignment direction. The substrate 31 is a substrate such as a glass substrate or a film substrate, and forms the uppermost surface of the counter substrate 30b.

(4) The alignment direction of the liquid crystal element LC changes according to the applied electric field (voltage). The liquid crystal layer LC1 modulates light passing through the inside of the liquid crystal layer LC1 according to the state of the electric field. The direction of the liquid crystal element LC changes due to an electric field (here, a horizontal electric field) applied between the pixel electrode 28 and the counter electrode 26, and the amount of light transmitted through the liquid crystal layer LC1 changes. In other words, the liquid crystal element LC is aligned based on the initial alignment direction defined in the lower alignment film 29 and the upper alignment film 32 when no electric field is applied between the pixel electrode 28 and the counter electrode 26. . Then, when an electric field is applied between the pixel electrode 28 and the counter electrode 26, the liquid crystal element LC is oriented in an alignment direction according to the strength of the applied electric field. Note that each of the plurality of sub-pixels 49 has the pixel electrode 28. The plurality of switching elements 24 for individually controlling the operations (light transmittance) of the plurality of sub-pixels 49 are electrically connected to the pixel electrodes 28, respectively.

As described above, the image display panel 30 according to the present embodiment is a horizontal electric field type liquid crystal display panel, and more specifically, an FFS (Fringe Field Switching) type liquid crystal display panel. However, the image display panel 30 is not limited to the FFS type, and may be any type of liquid crystal display panel. For example, the image display panel 30 may be a horizontal electric field type IPS (In Plane Switching) type liquid crystal display panel or a vertical electric field type liquid crystal display panel. For example, the image display panel 30 may be a vertical electric field type VA (Vertical Alignment) liquid crystal display panel or a vertical electric field type TN (Twisted Nematic) liquid crystal display panel. In the case of a vertical electric field type liquid crystal display panel, the counter electrode 26 is disposed on the counter substrate 30b.

FIG. 6 is a diagram showing an example of the relationship between the display area and the display divided area. The display area OA of the image display panel 30 has a plurality of display divided areas PA. The display area OA is an area obtained by combining all of the plurality of display divided areas PA. The display area OA shown in FIG. 6 is a total corresponding to a combination of the coordinates x1, x2,..., X9 set along the X direction and the coordinates y1, y2, y3, y4 set along the Y direction. It has a display divided area PA individually provided at a position corresponding to each of the 36 coordinates. Note that the number of display divided areas PA included in the display area OA is not limited to 36, and it is sufficient that two or more display divided areas PA are included. In addition, the display area OA has the display divided area PA divided along both the XY directions, but is not limited thereto, and the display divided area divided only along one of the X direction and the Y direction. It may have PA. The number and arrangement of the display divided areas PA included in the display area OA correspond to the number and arrangement of the first electrodes 81 included in the light control panel 80 described later. One or more pixels 48 are arranged in each of the display divided areas PA.

(Light source)
Next, the configuration of the light source unit 50 will be described. FIG. 7 is a diagram illustrating an example of a main configuration of the light source unit. The light source unit 50 has a side light positioned on the side of the display area OA when the display area OA is viewed in a plan view. In the example shown in FIG. 7, a plurality of light sources 51 are arranged along the X direction at both ends in the Y direction with respect to the light guide plate LA provided at a position corresponding to the display area OA in the XY plan view. ing. Note that the light source 51 may be arranged only on one end side in the Y direction with respect to the light guide plate LA. The light source 51 is, for example, a light emitting diode (LED: Light Emitting Diode) that emits white light, but is not limited to this and can be changed as appropriate. Light from the light source 51 is guided to the light guide plate LA to illuminate the entire display area OA from the back surface 30s side. In FIG. 7, the number of the light sources 51 arranged in a line along the X direction at each of one end side and the other end side in the Y direction is 9, and a total of 18 light sources 51 are arranged. It is an example of the number and the arrangement, and is not limited to this, and can be appropriately changed. For example, the light source unit 50 may be a so-called direct backlight having a light source such as an LED provided immediately below the display area OA when viewed in a plan view.

FIG. 7 schematically shows a plurality of light source areas GA corresponding to the coordinates of each of the plurality of display divided areas PA in order to show the correspondence between the light guide plate LA and the display area OA. When the light source 51 is turned on, light is guided by the light guide plate LA, so that each of the plurality of light source areas GA emits substantially the same amount of light from the back side of the display division area PA corresponding to each position. That is, the light source unit 50 of the first embodiment emits light with a predetermined output without controlling the light amount corresponding to the light amount required in each of the plurality of display divided areas PA. The light control unit 70 has a function related to control of the light amount corresponding to the light amount required in each of the plurality of display divided areas PA.

(Light control section)
Next, the dimming unit will be described. FIG. 8 is a diagram illustrating an example of a main configuration of the light control unit. As shown in FIG. 8, the light control panel 80 has a plurality of first electrodes 81 provided in the light control area DA. The first electrodes 81 are arranged in a matrix in the X direction and the Y direction. The light control panel 80 shown in FIG. 8 corresponds to a combination of the coordinates of x1, x2,..., X9 set along the X direction and the coordinates of y1, y2, y3, y4 set along the Y direction. The first electrode 81 is provided individually at a position corresponding to each of the coordinates of the total 36. Each of the plurality of first electrodes 81 is connected to the circuit section 90 via the wiring 86. The circuit unit 90 as the second signal output unit individually controls the potential of the first electrode 81 in accordance with the local dimming signal DI, and thereby controls each of the plurality of regions LD where the first electrode 81 is individually provided. Light transmittance is individually controlled. As described above, the light control area DA is divided into a plurality of areas LD in which the transmittance of light can be individually controlled. Here, since the number and the arrangement of the display division areas PA correspond to the number and the arrangement of the first electrodes 81, the positions of the plurality of display division areas PA correspond to the respective positions of the plurality of areas LD. It corresponds to the position. Note that, similarly to the display division area PA, the number of the areas LD included in the light control area DA is not limited to 36, and it is sufficient that at least two areas LD are included. Further, the dimming area DA includes the area LD arranged along both the X direction and the Y direction, but is not limited thereto, and the area LD arranged only along one of the X direction and the Y direction. May be provided. The light control area DA is provided so as to cover the entire display area OA in a plan view, and the transmittance of light that is guided by the light guide plate LA and illuminates the entire display area OA from the back side is adjusted in each of the plurality of areas LD. They are individually controllable.

FIG. 9 is a cross-sectional view illustrating an example of a schematic cross-sectional structure of the light control panel according to the first embodiment. As shown in FIG. 9, the light control panel 80 is a TN type liquid crystal panel, and has a first substrate 80a and a second substrate 80b. The first substrate 80a has a first electrode 81, a substrate 84, insulating

films

85a, 85b, 85c, switching elements 88, and a lower alignment film 89. The second substrate 80b has a substrate 72, a second electrode 82, and an upper alignment film 74. The switching element 88 has a channel 88a, a source 88b, a gate 88c, and a drain 88d. Hereinafter, the laminated structure of the light control panel 80 will be described.

The first substrate 80a has a substrate 84, an insulating film 85a, an insulating film 85b, an insulating film 85c, a first electrode 81, and a lower alignment film 89 stacked (superposed) in this order in the Z direction. The substrate 84 is a substrate such as a glass substrate or a film substrate. On the substrate 84, a channel 88a (island) is provided. The insulating film 85a is provided on the substrate 84 and in contact with the channel 88a. A gate 88c is provided on the insulating film 85a at a position overlapping with the channel 88a. The insulating film 85b is provided on the insulating film 85a and in contact with the gate 88c. A source 88b and a drain 88d are provided on the insulating film 85b at positions overlapping the channel 88a. Part of the source 88b and the drain 88d penetrate the insulating

films

85b and 85a and are connected to the channel 88a. The insulating film 85c is provided on the insulating film 85b and in contact with the source 88b and the drain 88d. Note that the gate 24c is disposed on the side opposite to the substrate with respect to the channel 24a, and the configuration of a so-called top gate has been described as an example, but the present invention is not limited to this. For example, the gate 24c may have a configuration of a bottom gate disposed between the channel 24a and the substrate via an insulating film. The first electrode 81 is provided on the insulating film 85c, and is provided for each region LD. The first electrode 81 is connected to the drain 88d. The first electrode 81 has, for example, a rectangular shape. The insulating

films

85a, 85b, 85c are made of, for example, an insulating member such as a silicon nitride film (SiNx). Further, the first electrode 81 and the second electrode 82 are, for example, transparent electrodes made of indium tin oxide (ITO) or the like.

The lower alignment film 89 is provided on the uppermost side of the first substrate 80a, in other words, provided on the first electrode 81 and the insulating film 85c. That is, the lower alignment film 89 becomes the surface of the first substrate 80a on the liquid crystal layer LC2 side. When no electric field (voltage) is applied between the second electrode 82 and the first electrode 81, the liquid crystal element LC in the liquid crystal layer LC2 is aligned according to the initial alignment direction given to the lower alignment film 89. I do. For example, by rubbing the lower alignment film 89 on the surface on the liquid crystal layer LC2 side, a plurality of grooves are formed on the surface on the liquid crystal layer LC2 side in one direction, that is, along the rubbing direction. Since the liquid crystal element LC near the lower alignment film 89 is aligned along the rubbing direction, the rubbing direction can be said to be the initial alignment direction. The lower alignment film 89 may be, for example, a rubbed film of a polyimide (PI) -based alignment film material. However, the lower alignment film 89 may be configured to be able to align the liquid crystal element LC in the initial alignment direction by a process other than rubbing such as optical alignment. For example, the lower alignment film 89 may be a photo alignment film. Since the lower alignment film 89 is an alignment film provided on the first substrate 80a side, the initial alignment direction of the lower alignment film 89 is lower than the second substrate 80b, that is, the lower side (upper side and lower side) of the light control panel 80. This is the initial orientation direction of the substrate on the opposite side).

The second substrate 80b has the upper alignment film 74, the second electrode 82, and the substrate 72 stacked (superposed) in the Z direction in this direction. The upper alignment film 74 is the surface of the second substrate 80b on the liquid crystal layer LC2 side. When no voltage is applied between the second electrode 82 and the first electrode 81, the liquid crystal element LC in the liquid crystal layer LC2 is aligned according to the initial alignment direction given to the upper alignment film 74. The initial alignment direction of the upper alignment film 74 is preferably orthogonal to the initial alignment direction of the lower alignment film 89, but the details of the initial alignment direction will be described later. Like the lower alignment film 89, the upper alignment film 74 may be capable of aligning the liquid crystal element LC in the initial alignment direction by a rubbing process, or may be capable of aligning the liquid crystal element LC in the initial alignment direction by another process such as optical alignment. Orientation may be possible. The upper alignment film 74 is an alignment film that is provided on the image display panel 30 side (upper side) of the lower alignment film 89 so as to face the lower alignment film 89. Further, since the upper alignment film 74 is an alignment film provided on the second substrate 80b side, the initial alignment direction of the upper alignment film 74 is on the second substrate 80b, that is, on the upper side (front side) of the light control panel 80. Is the initial orientation direction of the substrate.

The second electrode 82 is an electrode disposed to face the first electrode 81, and is a common electrode provided in the light control area DA of the light control panel 80 in the present embodiment. Note that the second electrode 82 may be configured with a plurality of block-shaped electrodes extending in the X direction or the Y direction in the light control area DA. The substrate 72a is a substrate such as a glass substrate or a film substrate, and forms the uppermost surface of the second substrate 80b.

The light control panel 80 stacked in this manner transmits light irradiated from the light source unit 50 by the voltage applied between the first electrode 81 and the second electrode 82 within the liquid crystal layer LC2 so as to reduce the transmittance. The light is transmitted to the rear surface 30 s of the image display panel 30 while being changed. The alignment direction of the liquid crystal element LC changes according to an applied electric field (voltage). The liquid crystal layer LC2 modulates light passing through the inside of the liquid crystal layer LC2 according to the state of the electric field. The direction of the liquid crystal element LC changes due to an electric field (here, a horizontal electric field) applied between the second electrode 82 and the first electrode 81, and the amount of light transmitted through the liquid crystal layer LC2 changes. In other words, when no electric field is applied between the second electrode 82 and the first electrode 81, the liquid crystal element LC is aligned based on the initial alignment direction defined in the lower alignment film 89 and the upper alignment film 74. ing. Then, when an electric field is applied between the second electrode 82 and the first electrode 81, the liquid crystal element LC is oriented in an alignment direction according to the strength of the applied electric field.

{Circle around (4)} A predetermined output potential provided by the circuit section 90 is applied to the source 88b. The drain 88d is electrically connected to the first electrode 81 via the wiring 86. The switching element 88 switches whether or not the drain current flows through the first electrode 81 according to the presence or absence of a signal to the gate 88c.

As described above, the light control panel 80 according to the present embodiment is a vertical electric field type liquid crystal panel, and more specifically, a TN type liquid crystal panel.

Next, a method of determining the transmittance of each of the plurality of regions LD will be described with reference to FIG. The image analysis unit 11 performs an analysis process for specifying the gradation value of the pixel 48 driven at the highest gradation among the plurality of pixels 48 included in the display divided area PA. The image analysis unit 11 individually performs an analysis process on each of the plurality of display divided areas PA. The dimming control unit 12 controls the plurality of display divided areas PA such that the light amount corresponding to the gradation value of the pixel 48 driven at the highest gradation in each of the plurality of display divided areas PA is applied to each of the plurality of display divided areas PA. The transmittance of each of the regions LD is determined.

For example, when each of the R, G, and B signals constituting the input signal IP is an 8-bit signal, the highest gradation value is (R, G, B) = (255, 255, 255), and the lowest gradation value is The key value is (R, G, B) = (0, 0, 0). In the first embodiment, when the gradation values of all the pixels 48 in the display divided area PA are (R, G, B) = (0, 0, 0), the light amount required for the display divided area PA is the minimum. The light amount becomes (0), and the transmittance of the area LD at the position corresponding to the display divided area PA becomes the lowest transmittance (0). Further, there is at least one pixel 48 in which the tone value of the pixel 48 exceeds (R, G, B) = (0, 0, 0), and the tone value of the pixel 48 driven at the highest tone is When (R, G, B) = (63, 63, 63) or less, the light amount required for the display divided area PA is the second smallest light amount (63), and the light amount required for the position corresponding to the display divided area PA is The transmittance of the region LD is the second lowest transmittance (0.25). Further, when the gradation value of the pixel 48 is (R, G, B) = (64, 0, 0), (R, G, B) = (0, 64, 0) or (R, G, B) = ( There is one or more pixels 48 exceeding (0, 0, 64), and the gradation value of the pixel 48 driven at the highest gradation is (R, G, B) = (127, 127, 127) or less. In this case, the amount of light required for the display divided area PA is the second largest light quantity (127), and the transmittance of the area LD corresponding to the display divided area PA is the second highest transmittance (0.5). Become. Further, when the gradation value of the pixel 48 is (R, G, B) = (128, 0, 0), (R, G, B) = (0, 128, 0) or (R, G, B) = ( When there is one or more pixels 48 exceeding (0, 0, 128), the amount of light required for the display divided area PA is the maximum light quantity (255), and the transmittance of the area LD at a position corresponding to the display divided area PA Has the highest transmittance (1). The relationship between the light quantity required for the display divided area PA and the transmittance of the area LD is merely an example and is not limited to this. The specific relationship between the gradation value, the light quantity, and the transmittance is appropriately determined. Can be changed.

The image analysis unit 11 outputs information indicating the result of the analysis process to the light control unit 12 and the correction unit 14. The dimming control unit 12 reflects, on the first signal DATA, information indicating the transmittance of each of the plurality of areas LD corresponding to the amount of light required for each of the plurality of display divided areas PA indicated by the analysis processing result. The dimming signal DI is generated and output to the dimming buffer 13 and the correction unit 14.

Next, a process regarding the output image signal OP performed according to the transmittance of the plurality of regions LD will be described with reference to FIG. The correction unit 14 performs a correction process of correcting the tone value of each of the plurality of pixels 48 included in each of the plurality of display divided areas PA according to the transmittance of each of the plurality of areas LD. The correction process is a process in which the lowest transmittance is set to 0 and the highest transmittance is set to 1, and the reciprocal of the transmittance is multiplied by the gradation value.

For example, when the gradation value of the pixel 48 driven at the highest gradation is (R, G, B) = (127, 127, 127), the transmittance of the region LD at the position corresponding to the display divided region PA Is controlled so as to have the second highest transmittance, and the light amount applied to the display divided area PA becomes the second largest light amount (127). Here, the gradation value of (R, G, B) = (127, 127, 127) is a light amount on the assumption that the light amount applied to the display divided area PA is the maximum light amount (255). is there. For this reason, when the gradation value of (R, G, B) = (127, 127, 127) is directly reflected on the output image signal OP without performing the correction, the amount of light irradiated on the display divided area PA is the maximum. When the light amount is smaller than the light amount (second light amount (127)), the display output corresponding to the gradation value of (R, G, B) = (127, 127, 127) cannot be performed. Therefore, in such a case, in the first embodiment, (R, G, B) = (127, 127, 127) according to the light amount (the second largest light amount (127)) irradiated to the display divided area PA. By correcting the gradation value of, the same output as the output corresponding to the gradation value of (R, G, B) = (127, 127, 127) in the case of the maximum light amount (255) is performed. To be able to Specifically, the transmittance of the region LD when the second largest amount of light (127) is emitted is the second highest transmittance (0.5). The reciprocal of this transmittance is 2. The correction unit 14 updates this gradation value with a value obtained by multiplying the gradation value of (R, G, B) = (127, 127, 127) by the reciprocal (2) of the transmittance. In this case, the corrected gradation value is (R, G, B) = (254, 254, 254). When the gradation value takes another value, and even when the transmittance takes another value, the correction section 14 performs a correction process by the same mechanism to update the gradation value of the pixel 48.

The correction unit 14 updates the gradation value of the pixel 48 included in each of the plurality of display divided areas PA according to the transmittance of each of the plurality of areas LD. Note that the correction unit 14 may omit the correction process for the display divided area PA corresponding to the area LD having the maximum transmittance (1). Thus, the correction unit 14 corrects the signal output to the image display panel 30 according to the transmittance, and reflects the signal on the output image signal.

In the first embodiment, since the pixel 48 has the fourth sub-pixel 49W, the correction unit 14 performs a conversion process of allocating a tone value assignable to the fourth sub-pixel 49W to the fourth sub-pixel 49W. And reflects it on the output image signal OP. For example, the correction unit 14 converts the gradation value of (R, G, B) = (254, 254, 254) after the correction processing into (R, G, B, W) = (0, 0, 0, 254). ). The correction unit 14 performs a correction process and a conversion process to generate an output image signal OP, and outputs the output image signal OP to the image buffer 15.

The image buffer 15 and the dimming buffer 13 are configured to function as a storage area configured by, for example, a RAM (Random Access Memory). The synchronizer 16 is configured to output the image frame of the input signal IP that is the source of the output image signal OP stored in the image buffer 15 and the input signal IP that is the source of the local dimming signal DI stored in the dimming buffer 13. The image buffer 15 and the dimming buffer 13 are output at the same timing by matching the image frame. This makes it possible to match the frame image displayed in the display area OA with the amount of light applied to the image display panel 30 when the frame image is displayed and output.

(4) The light source control unit 17 outputs the light source driving signal BL to the light source unit 50 so as to operate the light source unit 50 during a period in which the local dimming signal DI is output in response to the input of the input signal IP. The light source unit 50 turns on the plurality of light sources 51 according to the light source drive signal BL.

FIG. 10 is a flowchart illustrating an example of the flow of processing of the signal processing unit. The image analysis unit 11 performs an analysis process and specifies the pixel 48 having the maximum gradation for each of the plurality of display divided areas PA (Step S1). The dimming control unit 12 maps each of the plurality of areas LD included in the dimming area DA to the maximum gray level of each display division area PA according to the maximum gray level of each display division area PA specified in step S1. (Step S2). Specifically, the dimming control unit 12 generates, for example, a local dimming signal DI for setting each of the plurality of areas LD to have a transmittance corresponding to the maximum gradation for each display division area PA, and And the correction unit 14. The correction unit 14 acquires the transmittance distribution of the light control area DA indicated by the transmittance of each of the plurality of areas LD output from the light control controller 12 (step S3). The correction unit 14 corrects the gradation value of each pixel 48 according to the transmittance of each of the plurality of regions LD (Step S4).

(Transmission axis direction and initial orientation direction)
The display device 1 has the configuration described above, and the light control panel 80 is superimposed on the image display panel 30. By providing the dimming panel 80 and controlling the transmittance of each region LD in this manner, it is possible to adjust the amount of light applied to the image display panel 30 and improve the contrast. However, when the light control panel 80 is superimposed on the image display panel 30, the light from the light source unit 50 passes through both the light control panel 80 and the image display panel 30. It may decrease. On the other hand, the display device 1 according to the present embodiment suppresses a decrease in luminance by devising the transmission axis direction of the lower polarizing plate 52, the initial alignment direction of the light control panel 80, and the like. Hereinafter, the transmission axis direction and the initial alignment direction will be described.

FIG. 11 is a schematic diagram illustrating the transmission axis direction and the initial alignment direction according to the first embodiment. FIG. 11 shows the transmission axis direction or the initial alignment direction of each of the lower polarizing plate 52, the light control panel 80, the middle polarizing plate 54, the image display panel 30, and the upper polarizing plate 58 arranged along the Z direction. I have. Here, the transmission axis direction is a direction along the transmission axis of the polarizing plate. The transmission axis is an angle at which light that can be transmitted by the polarizing plate vibrates (polarization angle), and can be said to be a polarization axis. For example, when the transmission axis direction of the polarizing plate is the X direction, the polarizing plate transmits light that vibrates in the X direction and does not transmit light that vibrates in a direction other than the X direction among the incident light. As described above, the initial alignment direction is a direction set so that the liquid crystal element LC is aligned when no voltage (electric field) is applied to the liquid crystal panel.

Hereinafter, the transmission axis direction of the lower polarizing plate 52 is referred to as a transmission axis direction D1. The initial alignment direction of the first substrate 80a of the light control panel 80, that is, the initial alignment direction of the lower alignment film 89 is defined as the initial alignment direction D2, and the initial alignment direction of the second substrate 80b of the light control panel 80, that is, the upper alignment direction. The initial alignment direction of the film 74 is defined as an initial alignment direction D3. The transmission axis direction of the middle polarizing plate 54 is defined as a transmission axis direction D4. The initial alignment direction of the array substrate 30a of the image display panel 30, that is, the initial alignment direction of the lower alignment film 29 is defined as an initial alignment direction D5, and the initial alignment direction of the counter substrate 30b of the image display panel 30, that is, the upper alignment film 32 Is referred to as an initial alignment direction D6. The transmission axis direction of the upper polarizing plate 58 is defined as a transmission axis direction D7. Further, a reference axis along a predetermined direction is set as a reference axis AX1, and an axis orthogonal to the reference axis AX1 is set as a reference orthogonal axis AX2. Here, the reference axis AX1 may be an axis along any direction as long as it is an axis along the XY plane. In the present embodiment, the reference axis AX1 is an axis along the X direction. That is, it can be said that the reference axis AX1 is a direction along one of the outer sides of the rectangular image display panel 30 or the light control panel 80, for example. The reference orthogonal axis AX2 is an axis along the XY plane, and is an axis orthogonal to the reference axis AX1. Therefore, in the present embodiment, the reference orthogonal axis AX2 is an axis along the Y direction.

Before describing the transmission axis direction and the initial alignment direction, the twist direction of the liquid crystal element LC of the light control panel 80 will be described. The liquid crystal element LC in the liquid crystal layer LC2 is aligned in a state where no voltage is applied to the first electrode 81 and the second electrode 82 due to the initial alignment direction D2 of the lower alignment film 89 and the initial alignment direction D3 of the upper alignment film 74. The direction (initial alignment direction) is set. Specifically, the liquid crystal element LC in the liquid crystal layer LC2 is oriented so as to be gradually twisted about the Z direction as the center axis as going upward (toward the image display panel 30 from the lower polarizing plate 52). . Furthermore, among the plurality of liquid crystal elements LC in the liquid crystal layer LC2, the liquid crystal element LC located near the lower alignment film 89 is aligned along the initial alignment direction D2 of the lower alignment film 89. The plurality of liquid crystal elements LC in the liquid crystal layer LC2 gradually move from the initial alignment direction D2 of the lower alignment film 89 to the initial alignment direction D3 of the upper alignment film 74 toward the upper alignment film 74, that is, in the Z direction. The alignment direction changes, and the liquid crystal element LC located near the upper alignment film 74 is aligned along the initial alignment direction D3 of the upper alignment film 74. That is, the plurality of liquid crystal elements LC in the liquid crystal layer LC2 are arranged in the initial alignment direction D3 as the upper alignment film 74 is arranged, and in the Z direction as the lower alignment film 89 is arranged in the initial alignment direction D2. Are arranged around the center axis. This direction in which the liquid crystal element LC is twisted is referred to as the twisting direction. In the first embodiment, the initial alignment direction D2 of the lower alignment film 89 and the upper alignment film 74 are adjusted so that the twist direction of the liquid crystal element LC of the light control panel 80 is the clockwise direction T1 on the XY plane. The initial alignment direction D3 is set. As shown in FIG. 11, for example, the initial alignment direction D2 of the lower alignment film 89 is set so as to be directed to the X direction side, and the initial alignment direction D3 of the upper alignment film 74 is set so as to be directed to the Y direction side. Thus, the twist direction of the liquid crystal element LC of the light control panel 80 is the clockwise direction T1 on the XY plane. Note that the clockwise direction T1 is a clockwise direction with an axis orthogonal to the XY plane as a center axis.

As shown in FIG. 11, in the lower polarizing plate 52, in the XY plane (when viewed from the Z direction), the transmission axis direction D1 is the twist direction of the liquid crystal element LC of the light control panel 80 with respect to the reference axis AX1. The transmission axis is set so as to incline in the same direction as. As described above, in the first embodiment, the twisting direction of the liquid crystal element LC of the light control panel 80 is the clockwise direction T1. Therefore, in the first embodiment, the transmission axis direction D1 of the lower polarizing plate 52 is inclined in the clockwise direction T1 with respect to the reference axis AX1. Furthermore, in the present embodiment, the medium polarizing plate 54 is set such that the transmission axis direction D4 is not inclined with respect to the reference orthogonal axis AX2 but is along (parallel to) the reference orthogonal axis AX2. I have. Therefore, the transmission axis direction D1 of the lower polarizing plate 52 is inclined in the same direction as the twist direction of the liquid crystal element LC (here, clockwise direction T1) with respect to an axis orthogonal to the transmission axis direction D4 of the middle polarizing plate 54. It can be said that. The transmission axis direction D1 of the lower polarizing plate 52 is inclined with respect to the reference axis AX1, but is decomposed into a vector component in a direction along the reference axis AX1 and a vector component in a direction along the reference orthogonal axis AX2. In this case, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2. That is, in the transmission axis direction D1, the inclination angle with respect to the reference axis AX1 is smaller than 45 degrees. However, a preferable numerical range of the tilt angle will be described later.

The lower alignment film 89 of the first substrate 80a of the light control panel 80 has an initial alignment direction D2 in the XY plane (as viewed from the Z direction) whose liquid crystal element of the light control panel 80 is positioned with respect to the reference axis AX1. The lower polarizing plate 52 is inclined in a direction opposite to the twisting direction of the LC, in other words, in a direction opposite to the direction in which the transmission axis direction D1 of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the first embodiment, the initial alignment direction D2 of the lower alignment film 89 is inclined in the counterclockwise direction T2 on the XY plane with respect to the reference axis AX1. The counterclockwise direction T2 is a counterclockwise direction about an axis orthogonal to the XY plane as a center axis, and is a direction opposite to the clockwise direction T1. The initial alignment direction D2 of the lower alignment film 89 is inclined with respect to the reference axis AX1, but is decomposed into a vector component in a direction along the reference axis AX1 and a vector component in a direction along the reference orthogonal axis AX2. In this case, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2. That is, the inclination angle of the initial alignment direction D2 with respect to the reference axis AX1 is smaller than 45 degrees. However, a preferable numerical range of the tilt angle will be described later.

Thus, the transmission axis direction D1 of the lower polarizing plate 52 is inclined in the clockwise direction T1 with respect to the reference axis AX1, and the initial alignment direction D2 of the lower alignment film 89 is inclined in the counterclockwise direction T2 with respect to the reference axis AX1. Therefore, it can be said that the transmission axis direction D1 of the lower polarizing plate 52 is not parallel and not orthogonal to the transmission axis direction of the light control panel 80, that is, the initial alignment direction D2 of the lower alignment film 89. In addition, the transmission axis direction D1 of the lower polarizing plate 52 is not required to be parallel and perpendicular to the transmission axis direction of the light control panel 80, that is, the initial alignment direction D2 of the lower alignment film 89. It may be parallel or perpendicular to the axis AX1. Similarly, the initial alignment direction D2 of the lower alignment film 89 is not required to be parallel and not orthogonal to the transmission axis direction D1 of the lower polarizing plate 52. For example, the initial alignment direction D2 is parallel or orthogonal to the reference axis AX1. Is also good. However, as shown in the first embodiment, the transmission axis direction D1 of the lower polarizing plate 52 is inclined with respect to the reference axis AX1 in the same direction as the twisting direction of the liquid crystal element LC (here, clockwise direction T1). Preferably, the initial alignment direction D2 of the lower alignment film 89 is inclined with respect to the reference axis AX1 in a direction opposite to the direction of inclination of the transmission axis direction D1 of the lower polarizing plate 52 (here, a counterclockwise direction T2). Is preferred.

Further, the upper alignment film 74 of the second substrate 80b of the light control panel 80 has a structure in which the initial alignment direction D3 is equal to the reference orthogonal axis AX2 in the XY plane (when viewed from the Z direction). The element LC is tilted in the twisting direction, in other words, in the same direction as the direction in which the transmission axis direction D1 of the lower polarizing plate 52 is tilted with respect to the reference axis AX1. Therefore, in the first embodiment, the initial alignment direction D3 of the upper alignment film 74 is inclined in the clockwise direction T1 with respect to the reference orthogonal axis AX2. Although the initial alignment direction D3 of the upper alignment film 74 is inclined with respect to the reference orthogonal axis AX2, it is decomposed into a vector component in a direction along the reference axis AX1 and a vector component in a direction along the reference orthogonal axis AX2. In this case, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1. That is, the inclination angle of the initial alignment direction D2 with respect to the reference orthogonal axis AX2 is smaller than 45 degrees. However, a preferable numerical range of the tilt angle will be described later. However, the transmission axis direction D1 of the lower polarizing plate 52 does not necessarily need to be inclined with respect to the reference orthogonal axis AX2, and may be along the reference orthogonal axis AX2, for example.

As described above, in the middle polarizing plate 54, in the XY plane (as viewed from the Z direction), the transmission axis direction D4 is not inclined with respect to the reference orthogonal axis AX2, and is along the reference orthogonal axis AX2 (parallel to the reference orthogonal axis AX2). Is set).

In the lower alignment film 29 of the array substrate 30a of the image display panel 30, the initial alignment direction D5 is not inclined with respect to the reference orthogonal axis AX2 in the XY plane (as viewed from the Z direction), and (Parallel). That is, the initial alignment direction D5 of the lower alignment film 29 is along the transmission axis direction D4 of the middle polarizing plate 54.

In the upper alignment film 32 of the counter substrate 30b of the image display panel 30, the initial alignment direction D6 is along the initial alignment direction D5 of the lower alignment film 29 in the XY plane (as viewed from the Z direction). Parallel). That is, the initial alignment direction D6 of the upper alignment film 32 is along the reference orthogonal axis AX2, and more specifically, is along the transmission axis direction D4 of the middle polarizer 54.

In addition, the upper polarizing plate 58 is configured such that the transmission axis direction D7 is not inclined with respect to the reference axis AX1 and is along (referenced to) the reference axis AX1 in the XY plane (as viewed from the Z direction). Is set. That is, the transmission axis direction D7 of the upper polarizing plate 58 is orthogonal to the transmission axis direction D4 of the middle polarizing plate 54, the initial alignment direction D5 of the lower alignment film 29, and the initial alignment direction D6 of the upper alignment film 32. .

Next, the angles of the transmission axis direction and the initial alignment direction will be described. The angles of the transmission axis direction and the initial alignment direction described below indicate angles in the XY plane, that is, angles as viewed from the Z direction. The angle of inclination of the transmission axis direction D1 of the lower polarizing plate 52 with respect to the reference axis AX1 is preferably, for example, not less than 0 degrees and not more than 5 degrees. Further, the magnitude of the angle at which the initial alignment direction D2 of the lower alignment film 89 is inclined with respect to the reference axis AX1 is preferably, for example, 0 degrees or more and 5 degrees or less. Further, the magnitude of the angle at which the initial alignment direction D3 of the upper alignment film 74 is inclined with respect to the reference orthogonal axis AX2 is preferably, for example, not less than 0 degrees and not more than 5 degrees. More specifically, the angle of the transmission axis direction D1 of the lower polarizing plate 52 with respect to the reference axis AX1, the angle of the initial alignment direction D2 of the lower alignment film 89 with respect to the reference axis AX1, and the upper alignment film It is preferable that the initial orientation direction D3 of 74 is equal to the angle of inclination with respect to the reference orthogonal axis AX2, but they may be different from each other.

FIG. 12 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the first embodiment. Angle theta ₁ of Figure 12 is the angle between the initial orientation direction D2 of the transmission axis direction D1 and the lower alignment film 89 of the lower polarizing plate 52. That is, the initial alignment direction D2 of the lower alignment film 89 is counterclockwise T2 with respect to the transmission axis direction D1 of the lower polarizer 52, that is, in the direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80. It is inclined by an angle θ _1. Angle theta ₁ is preferably less than 10 degrees than 0 degrees. The angle theta ₂ in FIG. 12, an angle formed between the initial orientation direction D3 of the transmission axis direction D1 and the upper alignment film 74 of the lower polarizing plate 52. Angle theta ₂ is preferably less 95 degrees 85 degrees. Since the angle theta ₂ including the case is 90 degrees, the initial alignment direction D3 of the transmission axis direction D1 and the upper alignment film 74 of the lower polarizing plate 52 may be perpendicular. The angle theta ₃ in FIG. 12 is an angle formed between the transmission axis direction D4 of the transmission axis direction D1 and intermediate polarizing plate 54 of the lower polarizing plate 52. Angle theta ₃ is preferably not more than 95 degrees 90 degrees. Since the angle theta ₃ including the case is 90 degrees, the transmission axis direction D4 of the transmission axis direction D1 and intermediate polarizing plate 54 of the lower polarizer 52 may be perpendicular. In the first embodiment, the transmission axis direction D4 of the intermediate polarizing plate 54, because it is along the reference orthogonal axis AX2, the angle theta ₃ includes a transmission axis direction D1 and the reference quadrature axis AX2 of the lower polarizer 52 It can be said that it is the angle made.

The angle theta ₄ in FIG. 12, an angle formed between the initial orientation direction D3 of the initial alignment direction D2 and the upper alignment film 74 of the lower alignment film 89. Angle theta ₄ is preferably 80 degrees or less than 90 degrees. Since the angle theta ₂ including the case is 90 degrees, the initial alignment direction D3 of the initial alignment direction D2 and the upper alignment film 74 of the lower alignment film 89 may be orthogonal. Angle theta ₅ in FIG. 12 is an angle formed between the transmission axis direction D4 of the initial alignment direction D2 with intermediate polarizing plate 54 of the lower alignment layer 89. Angle theta ₅ is preferably less 95 degrees 85 degrees. Since the angle theta ₅ including the case is 90 degrees, the transmission axis direction D4 of the intermediate polarizing plate 54 and the initial alignment direction D2 of the lower alignment layer 89 may be orthogonal. In the first embodiment, since the transmission axis direction D4 of the middle polarizing plate 54 is along the reference orthogonal axis AX2, the angle θ ₅ is equal to the initial alignment direction D2 of the lower alignment film 89 and the reference orthogonal axis AX2. It can be said that it is the angle made.

The angle θ _{6 in} FIG. 12 is an angle between the initial alignment direction D3 of the upper alignment film 74 and the transmission axis direction D4 of the middle polarizing plate 54. The angle θ ₆ is preferably equal to or greater than 0 degrees and equal to or less than 5 degrees. Since the case where the angle θ ₆ is 0 degrees is included, the initial alignment direction D3 of the upper alignment film 74 and the transmission axis direction D4 of the middle polarizing plate 54 may be parallel. In the first embodiment, the transmission axis direction D4 of the intermediate polarizing plate 54, because it is along the reference orthogonal axis AX2, the angle theta ₅ is formed between the initial alignment direction D3 and the reference quadrature axis AX2 of the upper alignment film 74 It can be said that it is an angle.

FIG. 13 is a graph illustrating an example of the luminance of the display device according to the first embodiment. The horizontal axis in FIG. 13 is the viewing angle, and the vertical axis is the luminance of the image. The viewing angle refers to the angle of the viewpoint with respect to the screen of the display device. That is, when the viewing angle is 0 degrees, the viewpoint is in front of the screen of the display device, and as the viewing angle increases or decreases from 0 degrees, the viewpoint shifts from the front of the screen of the display device. A line segment L1Z1 in FIG. 13 indicates the luminance at each viewing angle of the display device according to the first comparative example. The display device according to the first comparative example has the layered structure shown in FIG. 3 of the first embodiment, but the transmission axis and the initial alignment direction are parallel or orthogonal to each other. That is, in the display device according to the first comparative example, the transmission axis direction of the lower polarizing plate is perpendicular to the initial alignment direction of the lower alignment film of the light control panel, and the initial alignment direction of the lower alignment film of the light control panel is: The initial alignment direction of the upper alignment film of the light control panel is orthogonal to the initial alignment direction of the upper alignment film of the light control panel, and the transmission axis direction of the middle polarizer is parallel to the transmission axis direction of the middle polarizer. The initial alignment direction of the lower alignment film and the upper alignment film of the image display panel is parallel, and the initial alignment direction of the lower alignment film and the upper alignment film of the image display panel is orthogonal to the transmission axis direction of the upper polarizing plate. . Further, the twist direction of the liquid crystal element of the light control panel of the first comparative example is the same clockwise direction T1 as in the first embodiment. Further, a line segment L1 in FIG. 13 indicates the luminance for each viewing angle of the display device 1 according to the first embodiment.

As shown by the line segment L1 in FIG. 13, the luminance of the display device 1 according to the first embodiment is higher than the luminance of the display device of the first comparative example indicated by the line segment L1Z1. That is, the brightness is increased by inclining the transmission axis and the initial alignment direction. More specifically, in the display device 1 according to the first embodiment, at least the transmission axis direction D1 of the lower polarizing plate 52 and the initial alignment direction D2 of the lower alignment film 89 of the light control panel 80 are not parallel and are not orthogonal. Is set as follows. Therefore, the light transmitted through the lower polarizing plate 52 is prevented from being completely blocked by the lower alignment film 89 of the light control panel 80. Therefore, according to the display device 1 according to the first embodiment, the amount of light transmitted through the light control panel 80 can be increased, and a decrease in luminance can be suppressed.

FIG. 14 is a graph showing an example of the contrast of the display device according to the first embodiment. The horizontal axis in FIG. 14 is the viewing angle, and the vertical axis is the image contrast. A line segment L2Z1 in FIG. 14 is a contrast for each viewing angle of the display device according to the first comparative example, and a line segment L2 is a contrast for each viewing angle of the display device 1 according to the first embodiment. As shown in FIGS. 13 and 14, the display device 1 according to the first embodiment can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

As described above, the display device 1 according to the first embodiment includes the image display panel 30 having the plurality of pixels 48, the light source unit 50, the light control panel 80, and the lower polarizing plate 52. The light source unit 50 is provided on the back surface 30 s side of the image display panel 30. The light control panel 80 is provided between the image display panel 30 and the light source unit 50, and includes a lower alignment film 89 on the light source unit 50 side, a plurality of first electrodes 81 arranged in a matrix, and a lower alignment film 89. , An upper alignment film 74 provided on the image display panel 30 side of the lower alignment film 89 and the second electrode 82, and a liquid crystal layer LC2. Then, the light control panel 80 changes the transmittance of the light emitted from the light source unit 50 in the liquid crystal layer LC2 while changing the transmittance of the light, based on the voltage applied between the first electrode 81 and the second electrode 82. The display panel 30 is configured to be able to transmit light to the back surface 30 s side. The lower polarizing plate 52 is provided between the light control panel 80 and the light source unit 50. The transmission axis direction D1 of the lower polarizing plate 52 is not parallel to the initial alignment direction D2 of the lower alignment film 89, and is along a direction that is not orthogonal. This display device 1 improves the viewing angle characteristics by providing the light control panel 80 so as to be superimposed on the image display panel 30, and adjusts the transmission axis direction D1 of the lower polarizing plate 52 and the initial alignment direction of the light control panel 80. By not being parallel and not orthogonal, the amount of light transmitted through the light control panel 80 can be increased, and a decrease in luminance can be suppressed.

The transmission axis direction D1 of the lower polarizing plate 52 is one of clockwise and counterclockwise with respect to the reference axis AX1 along the predetermined direction (the clockwise direction T1 in the first embodiment). The initial orientation direction D2 of the lower orientation film 89 is inclined to the other of the clockwise direction and the counterclockwise direction (the counterclockwise direction T2 side in the first embodiment) with respect to the reference axis. In this display device 1, by inclining the transmission axis direction D <b> 1 of the lower polarizing plate 52 and the initial alignment direction D <b> 2 of the lower alignment film 89 in the opposite directions, it is possible to appropriately suppress a decrease in luminance.

The initial alignment direction D3 of the upper alignment film 74 is one of clockwise and counterclockwise with respect to a reference orthogonal axis AX2 orthogonal to the reference axis AX1 (the clockwise direction T1 in the first embodiment). Leaning on. In this way, the display device 1 can appropriately suppress the decrease in luminance by tilting the initial alignment direction D3 of the upper alignment film 74 in the same direction as the transmission axis direction D1 of the lower polarizing plate 52.

The initial alignment direction D2 of the lower alignment film 89 and the initial alignment direction D3 of the upper alignment film 74 are determined by the state in which no voltage is applied to the first electrode 81 and the second electrode 82 of the liquid crystal element LC in the liquid crystal layer LC2. Then, as it goes from the lower polarizing plate 52 side to the image display panel 30 side (as it goes upward), it is twisted in one of clockwise and counterclockwise directions (clockwise direction T1 side in the first embodiment). Is set. As described above, the display device 1 tilts the transmission axis direction D1 of the lower polarizing plate 52 in the same direction as the twisting direction of the liquid crystal element LC, and initializes the lower alignment film 89 in the direction opposite to the twisting direction of the liquid crystal element LC. By inclining the direction D2, a decrease in luminance can be suitably suppressed.

The display device 1 includes a middle polarizing plate 54 provided between the light control panel 80 and the image display panel 30, and an upper polarizing plate 58 provided on the front surface 30 t opposite to the back surface 30 s of the image display panel 30. And In this display device 1, the lower polarizing plate 52, the light control panel 80, the middle polarizing plate 54, the image display panel 30, and the upper polarizing plate 58 are arranged in this order, so that the viewing angle characteristics are improved and the luminance is reduced. Can be suppressed.

The transmission axis direction D4 of the middle polarizing plate 54 is along the reference orthogonal axis AX2 orthogonal to the reference axis AX1. By setting the transmission axis direction D4 of the middle polarizing plate 54 in this manner, the display device 1 can appropriately maintain image quality such as color balance.

(4) The initial alignment directions D5 and D6 of the image display panel 30 are along the reference orthogonal axis AX2, and the transmission axis direction D7 of the upper polarizing plate 58 is along the reference axis AX1. By setting the initial alignment directions D5 and D6 of the image display panel 30 and the transmission axis direction D7 of the upper polarizing plate 58 in this manner, the image quality such as color balance can be appropriately maintained.

(First Modification)
Next, a first modified example which is a modified example of the first embodiment will be described. The display device 1A according to the first modified example is different from the first embodiment in the twist direction of the liquid crystal element LC. In the first modified example, description of portions having the same configuration as the first embodiment will be omitted.

FIG. 15 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to a first modification. As shown in FIG. 15, in the first modification, the initial alignment of the lower alignment film 89 is performed so that the twisting direction of the liquid crystal element LC of the light control panel 80 is the counterclockwise direction T2 on the XY plane. The direction D2 and the initial alignment direction D3 of the upper alignment film 74 are set. That is, the twisting direction of the liquid crystal element LC in the first modification is opposite to that in the first embodiment. As shown in FIG. 15, for example, the initial alignment direction D2A of the lower alignment film 89 is set so as to face the X direction, and the initial alignment direction D3A of the upper alignment film 74 is set so as to face the direction opposite to the Y direction. Accordingly, the twisting direction of the liquid crystal element LC of the light control panel 80 becomes the counterclockwise direction T2 on the XY plane. In other words, the initial alignment direction D2A of the lower alignment film 89 is set to be in the same direction as the initial alignment direction D2 of the lower alignment film 89 of the first embodiment, and the initial alignment direction D3A of the upper alignment film 74 is The first alignment direction is set to be opposite to the initial alignment direction D3 of the upper alignment film 74 of the first embodiment.

As shown in FIG. 15, the transmission axis direction D1A of the lower polarizing plate 52 in the first modified example is, with respect to the reference axis AX1, in the XY plane (as viewed from the Z direction), the liquid crystal element LC of the light control panel 80. Are tilted in the same direction as the torsional direction, that is, in the counterclockwise direction T2. In other words, the transmission axis direction D1A of the lower polarizing plate 52 is the same as the twist direction of the liquid crystal element LC (here, the anti-twist direction) with respect to the axis orthogonal to the transmission axis direction D4A of the middle polarizing plate 54 of the first modification. It can also be said that it is inclined in the clockwise direction T2). The transmission axis direction D1A of the lower polarizing plate 52 is similar to the transmission axis direction D1 of the first embodiment in that the vector component in the direction along the reference axis AX1 is smaller than the vector component in the direction along the reference orthogonal axis AX2. Is also higher.

In addition, the initial alignment direction D2A of the lower alignment film 89 of the light control panel 80 according to the first modified example is different from the reference axis AX1 in the XY plane (as viewed from the Z direction). It is inclined in the direction opposite to the twisting direction of the LC (the direction opposite to the inclination of the transmission axis direction D1 of the lower polarizing plate 52), that is, in the clockwise direction T1. Note that, also in the initial alignment direction D2A of the lower alignment film 89, similarly to the initial alignment direction D2 of the first embodiment, the vector component in the direction along the reference axis AX1 is smaller than the vector component in the direction along the reference orthogonal axis AX2. Is also higher.

Further, the initial alignment direction D3A of the upper alignment film 74 of the light control panel 80 according to the first modified example is different from the reference orthogonal axis AX2 in the XY plane (as viewed from the Z direction). The element LC is inclined in the same direction as the twisting direction (the same direction as the inclination of the transmission axis direction D1 of the lower polarizing plate 52), that is, in the counterclockwise direction T2. The initial alignment direction D3A of the upper alignment film 74 is similar to the initial alignment direction D3 of the first embodiment in that the vector component in the direction along the reference orthogonal axis AX2 is smaller than the vector component in the direction along the reference axis AX1. Is also higher.

透過 The transmission axis direction D4A of the middle polarizing plate 54 according to the first modification is the same as the transmission axis direction D4 of the middle polarizing plate 54 according to the first embodiment. The initial alignment direction D5A of the lower alignment film 29 and the initial alignment direction D6A of the upper alignment film 32 according to the first modification are the initial alignment direction D5 and the initial alignment direction according to the first embodiment, respectively. It is the same direction as the direction D6. The transmission axis direction D7A of the upper polarizing plate 58 according to the first modification is the same as the transmission axis direction D7 of the upper polarizing plate 58 according to the first embodiment.

FIG. 16 is a diagram showing the relationship between the transmission axis direction and the initial alignment direction in the first modification. The angle θ _{1A in} FIG. 16 is an angle between the transmission axis direction D1A of the lower polarizing plate 52 and the initial alignment direction D2A of the lower alignment film 89. That is, the initial alignment direction D2A of the lower alignment film 89 is angled with respect to the transmission axis direction D1A of the lower polarizing plate 52 in the clockwise direction T1, that is, in the direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80. It is inclined by θ _1A . The angle θ _1A is preferably greater than 0 degrees and 10 degrees or less. The angle θ _2A is the angle between the transmission axis direction D1A of the lower polarizing plate 52 and the initial alignment direction D3A of the upper alignment film 74. It is preferable that the angle θ _2A is not less than 85 degrees and not more than 95 degrees. The angle θ _3A is an angle between the transmission axis direction D1A of the lower polarizing plate 52 and the transmission axis direction D4A of the middle polarizing plate 54. It is preferable that the angle θ _3A is not less than 90 degrees and not more than 95 degrees.

The angle θ _{4A in} FIG. 16 is the angle between the initial alignment direction D2A of the lower alignment film 89 and the initial alignment direction D3A of the upper alignment film 74. The angle θ _4A is preferably 80 degrees or more and 90 degrees or less. The angle θ _5A is an angle formed between the initial alignment direction D2A of the lower alignment film 89 and the transmission axis direction D4A of the middle polarizing plate 54. It is preferable that the angle _θ5A is not less than 85 degrees and not more than 95 degrees. The angle θ _6A is an angle formed between the initial alignment direction D3A of the upper alignment film 74 and the transmission axis direction D4A of the middle polarizing plate 54. The angle θ _6A is preferably equal to or greater than 0 degree and equal to or less than 5 degrees.

As described above, in the first modified example, the twisting direction of the liquid crystal element LC of the light control panel 80 is opposite to that of the first embodiment, so that the direction of the transmission axis direction D1A of the lower polarizing plate 52 is inclined. The direction in which the initial alignment direction D2A of the lower alignment film 89 tilts and the direction in which the initial alignment direction D3A of the upper alignment film 74 tilts are also opposite to those in the first embodiment. The display device 1A according to the first modified example has the transmission axis direction D1A of the lower polarizing plate 52 and the initial alignment direction D2A of the lower alignment film 89 of the light control panel 80, like the display device 1 according to the first embodiment. By not being parallel and not orthogonal, it is possible to suppress a decrease in luminance.

FIG. 17 is a graph illustrating an example of the luminance of the display device according to the first modification. A line segment L1Z2 in FIG. 17 indicates the luminance at each viewing angle of the display device according to the second comparative example. In the display device according to the second comparative example, the twisting direction of the liquid crystal element of the light control panel is the counterclockwise direction T2 opposite to the first comparative example, but the other configurations are the same as those of the first comparative example. Is the same. A line segment L1A in FIG. 17 indicates the luminance for each viewing angle of the display device 1A according to the first modification. As shown in FIG. 17, the brightness of the display device 1A according to the first modified example is higher than the brightness of the display device of the second comparative example.

FIG. 18 is a graph showing an example of the contrast of the display device according to the first modification. The line segment L2Z2 in FIG. 18 is the contrast for each viewing angle of the display device according to the second comparative example, and the line segment L2A is the contrast for each viewing angle of the display device 1A according to the first modification. As shown in FIG. 18, the display device 1A according to the first modification can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

(2nd Embodiment)
Next, a second embodiment will be described. The display device 1B according to the second embodiment is also inclined in the transmission axis direction of the middle polarizer 54, the initial alignment direction of the image display panel 30, and the initial alignment direction of the upper polarizer 58, in the first embodiment. And different. In the second embodiment, description of portions having the same configuration as the first embodiment will be omitted.

FIG. 19 is a schematic diagram illustrating the transmission axis direction and the initial alignment direction according to the second embodiment. As shown in FIG. 19, in the second embodiment, the initial alignment direction of the lower alignment film 89 is set such that the twist direction of the liquid crystal element LC of the light control panel 80 is the clockwise direction T1 on the XY plane. D2 and the initial alignment direction D3 of the upper alignment film 74 are set. That is, the twist direction of the liquid crystal element LC in the second embodiment is the same as that in the first embodiment.

透過 The transmission axis direction D1B of the lower polarizing plate 52 in the second embodiment is the same as the transmission axis direction D1 in the first embodiment. The initial alignment direction D2B of the lower alignment film 89 of the light control panel 80 according to the second embodiment is the same as the initial alignment direction D2 in the first embodiment. The initial alignment direction D3B of the upper alignment film 74 of the light control panel 80 according to the second embodiment is the same as the initial alignment direction D3 in the first embodiment.

On the other hand, in the middle polarizing plate 54 in the second embodiment, in the XY plane (as viewed from the Z direction), the transmission axis direction D4B has a twist of the liquid crystal element LC of the light control panel 80 with respect to the reference orthogonal axis AX2. The transmission axis direction D1B of the lower polarizing plate 52 is inclined in the opposite direction to the reference axis AX1. Therefore, in the second embodiment, the transmission axis direction D4B of the middle polarizer 54 is inclined in the counterclockwise direction T2 with respect to the reference orthogonal axis AX2. Although the transmission axis direction D4B of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2, the vector component in the direction along the reference orthogonal axis AX2 is larger than the vector component in the direction along the reference axis AX1. Is getting higher. That is, in the transmission axis direction D4B, the inclination angle with respect to the reference orthogonal axis AX2 is smaller than 45 degrees. However, a preferable numerical range of the tilt angle will be described later.

Further, the lower alignment film 29 of the image display panel 30 in the second embodiment has an initial alignment direction D5B in the XY plane (as viewed from the Z direction) of the light control panel 80 with respect to the reference orthogonal axis AX2. The transmission axis direction D1B of the lower polarizing plate 52 is inclined in a direction opposite to the direction in which the liquid crystal element LC is twisted, in other words, in a direction opposite to the direction in which the transmission axis direction D1B of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the second embodiment, the initial alignment direction D5B of the lower alignment film 29 is inclined in the counterclockwise direction T2 with respect to the reference orthogonal axis AX2. Although the initial alignment direction D5B of the lower alignment film 29 is inclined with respect to the reference orthogonal axis AX2, the vector component in the direction along the reference orthogonal axis AX2 is larger than the vector component in the direction along the reference axis AX1. Is getting higher. That is, in the transmission axis direction D4B, the inclination angle with respect to the reference orthogonal axis AX2 is smaller than 45 degrees. In the upper alignment film 32 of the image display panel 30 in the second embodiment, the initial alignment direction D6B is along the initial alignment direction D5B of the lower alignment film 29.

Further, in the upper polarizing plate 58 in the second embodiment, in the XY plane (as viewed from the Z direction), the transmission axis direction D7B has a twist of the liquid crystal element LC of the light control panel 80 with respect to the reference axis AX1. The transmission axis direction D1B of the lower polarizer 52 is inclined in the same direction as the reference axis AX1. Therefore, in the second embodiment, the transmission axis direction D7B of the upper polarizing plate 58 is inclined in the clockwise direction T1 with respect to the reference axis AX1. Although the transmission axis direction D7B of the upper polarizing plate 58 is inclined with respect to the reference axis AX1, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2. Has become. That is, in the transmission axis direction D4B, the inclination angle with respect to the reference axis AX1 is smaller than 45 degrees.

Next, the angles of the transmission axis direction and the initial alignment direction will be described. It is preferable that the magnitude of the angle at which the transmission axis direction D4B of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2 is, for example, 0 degrees or more and 5 degrees or less. Further, the magnitude of the angle at which the initial alignment directions D5B and D6B of the image display panel 30 are inclined with respect to the reference orthogonal axis AX2 is preferably, for example, 0 degrees or more and 5 degrees or less. Further, it is preferable that the magnitude of the angle at which the transmission axis direction D7B of the upper polarizing plate 58 is inclined with respect to the reference axis AX1 is, for example, 0 degrees or more and 5 degrees or less. More specifically, the magnitude of the angle at which the transmission axis direction D4B of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2, and the magnitude of the angle at which the initial orientation directions D5B and D6B of the image display panel 30 are inclined with respect to the reference orthogonal axis AX2. The angle of inclination of the transmission axis direction D7B of the upper polarizing plate 58 with respect to the reference axis AX1 is preferably equal, but may be different from each other. Furthermore, in addition, although the transmission axis directions D1B, D4B, and D7B and the initial alignment directions D2B, D3B, D5B, and D6B are preferably equal in inclination angle, they may be different from each other.

FIG. 20 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the second embodiment. The angle θ _{1B in} FIG. 20 is an angle between the transmission axis direction D1B of the lower polarizing plate 52 and the initial alignment direction D2B of the lower alignment film 89. That is, the initial alignment direction D2B of the lower alignment film 89 is in a counterclockwise direction T2 with respect to the transmission axis direction D1B of the lower polarizing plate 52, that is, in a direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80. It is inclined by the angle θ _1B . The angle θ _1B is preferably greater than 0 degrees and equal to or less than 10 degrees. The angle θ _2B is an angle between the transmission axis direction D1B of the lower polarizing plate 52 and the initial alignment direction D3B of the upper alignment film 74. It is preferable that the angle θ _2B is not less than 85 degrees and not more than 95 degrees. The angle θ _3B is an angle formed between the transmission axis direction D1B of the lower polarizing plate 52 and the transmission axis direction D4B of the middle polarizing plate 54. The angle θ _3B is preferably 90 degrees or more and 100 degrees or less. The angle θ _7B is an angle between the transmission axis direction D1B of the lower polarizing plate 52 and the initial alignment directions D5B and D6B of the image display panel 30. The angle θ _7B is preferably 90 degrees or more and 100 degrees or less. The angle θ _8B is an angle between the transmission axis direction D1B of the lower polarizing plate 52 and the transmission axis direction D7B of the upper polarizing plate 58. The angle θ _8B is preferably equal to or greater than 0 degrees and equal to or less than 5 degrees.

The angle θ _{4A in} FIG. 20 is the angle between the initial alignment direction D2B of the lower alignment film 89 and the initial alignment direction D3B of the upper alignment film 74. Angle θ _4B is preferably 80 degrees or more and 90 degrees or less. The angle θ _5B is an angle formed between the initial alignment direction D2B of the lower alignment film 89 and the transmission axis direction D4B of the middle polarizing plate 54. The angle _θ5B is preferably 85 degrees or more and 100 degrees or less. The angle θ _9B is an angle between the initial alignment direction D2B of the lower alignment film 89 and the initial alignment directions D5B and D6B of the image display panel 30. It is preferable that the angle θ _9B is not less than 85 degrees and not more than 100 degrees. The angle θ _10B is an angle between the initial alignment direction D2B of the lower alignment film 89 and the transmission axis direction D7B of the upper polarizing plate 58. The angle θ _10B is preferably equal to or greater than 0 degree and equal to or less than 10 degrees.

The angle θ _{6B in} FIG. 20 is an angle between the initial alignment direction D3B of the upper alignment film 74 and the transmission axis direction D4B of the middle polarizer 54. Angle θ _6B is preferably equal to or greater than 0 degrees and equal to or less than 10 degrees. The angle θ _11B is an angle between the initial alignment direction D3B of the upper alignment film 74 and the initial alignment directions D5B and D6B of the image display panel 30. The angle θ _11B is preferably equal to or greater than 0 degrees and equal to or less than 10 degrees. The angle θ _12B is an angle formed between the initial alignment direction D3B of the upper alignment film 74 and the transmission axis direction D7B of the upper polarizing plate 58. It is preferable that the angle θ _12B is not less than 85 degrees and not more than 95 degrees.

The angle θ _{13B in} FIG. 20 is the angle between the transmission axis direction D4B of the middle polarizer 54 and the initial alignment directions D5B and D6B of the image display panel 30. The angle θ _13B is preferably equal to or greater than 0 degree and equal to or less than 5 degrees. The angle θ _14B is an angle formed between the transmission axis direction D4B of the middle polarizing plate 54 and the transmission axis direction D7B of the upper polarizing plate 58. The angle θ _14B is preferably 90 degrees or more and 100 degrees or less.

The angle θ _{15B in} FIG. 20 is an angle formed between the initial alignment directions D5B and D6B of the image display panel 30 and the transmission axis direction D7B of the upper polarizing plate 58. The angle θ _15B is preferably equal to or greater than 90 degrees and equal to or less than 100 degrees.

As described above, the display device 1B according to the second embodiment includes the transmission axis direction D1B of the lower polarizing plate 52 and the initial alignment direction D2B of the lower alignment film 89 of the light control panel 80, as in the first embodiment. Are not parallel and not orthogonal to each other, it is possible to suppress a decrease in luminance.

Furthermore, in the second embodiment, the transmission axis direction D4B of the middle polarizing plate 54 is on the other side (here, counterclockwise direction T2) of the clockwise direction and the counterclockwise direction with respect to the reference orthogonal axis AX2. Leaning. In this manner, the display device 1B can appropriately suppress the decrease in luminance by tilting the transmission axis direction D4B of the middle polarizing plate 54 in the direction opposite to the transmission axis direction D1 of the lower polarizing plate 52.

The initial orientation directions D5B and D6B of the image display panel 30 are inclined to the other side (here, the counterclockwise direction T2) of the clockwise direction and the counterclockwise direction with respect to the reference orthogonal axis AX2. The transmission axis direction D7B of the plate 58 is inclined with respect to the reference axis AX1 in one of clockwise and counterclockwise directions (here, clockwise direction T1). As described above, the display device 1B can appropriately suppress the decrease in luminance by tilting the initial alignment directions D5B and D6B of the image display panel 30 and the transmission axis direction D7B of the upper polarizing plate 58.

FIG. 21 is a graph illustrating an example of the luminance of the display device according to the second embodiment. A line segment L1Z1 in FIG. 21 indicates the luminance at each viewing angle of the display device according to the first comparative example. The line segment L1B indicates the luminance for each viewing angle of the display device 1B according to the second embodiment. As shown in FIG. 21, the brightness of the display device 1B according to the second embodiment is higher than the brightness of the display device of the first comparative example.

FIG. 22 is a graph showing an example of the contrast of the display device according to the second embodiment. A line segment L2Z1 in FIG. 22 is a contrast for each viewing angle of the display device according to the first comparative example, and a line segment L2B is a contrast for each viewing angle of the display device 1B according to the second embodiment. As shown in FIG. 22, the display device 1B according to the second embodiment can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

(Second Modification)
Next, a second modification which is a modification of the second embodiment will be described. The display device 1C according to the second modification is different from the second embodiment in the twist direction of the liquid crystal element LC. In the second modified example, description of portions having the same configuration as the second embodiment will be omitted.

FIG. 23 is a schematic diagram illustrating the transmission axis direction and the initial alignment direction according to the second modification. As shown in FIG. 23, in the second modification, the initial alignment of the lower alignment film 89 is performed so that the twisting direction of the liquid crystal element LC of the light control panel 80 is the counterclockwise direction T2 on the XY plane. The direction D2C and the initial alignment direction D3C of the upper alignment film 74 are set.

As shown in FIG. 23, the transmission axis direction D1C of the lower polarizing plate 52 in the second modification is the same as the transmission axis direction D1A (see FIG. 15) in the first modification. The initial alignment direction D2C of the lower alignment film 89 of the light control panel 80 according to the second modification is the same as the initial alignment direction D2A (see FIG. 15) in the first modification. The initial alignment direction D3C of the upper alignment film 74 of the light control panel 80 according to the second modification is the same as the initial alignment direction D3A (see FIG. 15) in the first modification. That is, in the second modification, the twisting direction of the liquid crystal element LC of the light control panel 80 is opposite to that of the second embodiment, so that the tilt direction of the transmission axis direction D1C of the lower polarizing plate 52 and the lower alignment film The direction of inclination of the initial alignment direction D2C of 89 and the direction of inclination of the initial alignment direction D3C of the upper alignment film 74 are also opposite to those in the second embodiment.

Further, the transmission axis direction D4C of the middle polarizing plate 54 in the second modification is the twist direction of the liquid crystal element LC of the light control panel 80 with respect to the reference orthogonal axis AX2 on the XY plane (as viewed from the Z direction). In other words, in other words, in the same direction as the direction in which the transmission axis direction D1C of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the second modification, the transmission axis direction D4C of the middle polarizing plate 54 is inclined in the counterclockwise direction T2 with respect to the reference orthogonal axis AX2. That is, the transmission axis direction D4C of the middle polarizing plate 54 is inclined in the counterclockwise direction T2 as in the second embodiment, but the twisting direction of the liquid crystal element LC of the light control panel 80 and the transmission axis direction of the lower polarizing plate 52 are different. The direction of inclination of the direction D1C relative to the direction of inclination is opposite to that of the second embodiment. In the transmission axis direction D4C of the middle polarizing plate 54, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1.

Further, the initial alignment direction D5C of the lower alignment film 29 of the image display panel 30 in the second modified example is such that the liquid crystal of the light control panel 80 is aligned with respect to the reference orthogonal axis AX2 on the XY plane (as viewed from the Z direction). The element LC is tilted in the same direction as the twisting direction, in other words, in the same direction as the direction in which the transmission axis direction D1C of the lower polarizing plate 52 is tilted with respect to the reference axis AX1. Therefore, in the second modification, the initial alignment direction D5C of the lower alignment film 29 is inclined in the counterclockwise direction T2 with respect to the reference orthogonal axis AX2. That is, although the initial alignment direction D5C of the lower alignment film 29 is inclined in the counterclockwise direction T2 as in the second embodiment, the twisting direction of the liquid crystal element LC of the light control panel 80 and the transmission axis of the lower polarizing plate 52 are different. The direction of inclination of the direction D1C relative to the direction of inclination is opposite to that of the second embodiment. In the initial alignment direction D5C of the lower alignment film 29, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1. In addition, the initial alignment direction D6C of the upper alignment film 32 of the image display panel 30 in the second modification is along the initial alignment direction D5C of the lower alignment film 29.

Further, the transmission axis direction D7C of the upper polarizing plate 58 in the second modified example is the twist direction of the liquid crystal element LC of the light control panel 80 with respect to the reference axis AX1 on the XY plane (as viewed from the Z direction). In other words, in other words, in the direction opposite to the direction in which the transmission axis direction D1C of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the second modification, the transmission axis direction D7C of the upper polarizing plate 58 is inclined in the clockwise direction T1 with respect to the reference axis AX1. That is, the transmission axis direction D7C of the upper polarizing plate 58 is inclined in the clockwise direction T1 as in the second embodiment, but the twist direction of the liquid crystal element LC of the light control panel 80 and the transmission axis direction of the lower polarizing plate 52. The inclination direction relative to the inclination direction of D1C is opposite to that of the second embodiment. In the transmission axis direction D7C of the upper polarizing plate 58, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2.

Next, the angles of the transmission axis direction and the initial alignment direction will be described. The magnitude of the angle at which the transmission axis direction D4C of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2, the magnitude of the angle at which the initial alignment directions D5C and D6C of the image display panel 30 are inclined with respect to the reference orthogonal axis AX2, and The magnitude of the angle at which the transmission axis direction D7C of 58 is inclined with respect to the reference axis AX1 is the same as in the second embodiment.

FIG. 24 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the second modification. Angle theta _1C of FIG. 24, an angle formed between the initial orientation direction D2C the transmission axis direction D1C and the lower alignment film 89 of the lower polarizing plate 52. That is, the initial alignment direction D2C of the lower alignment film 89 is angled with respect to the transmission axis direction D1C of the lower polarizing plate 52 in the clockwise direction T1, that is, in the direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80. It is inclined by θ _1C . The angle θ _1C is preferably greater than 0 degree and equal to or less than 10 degrees. The angle θ _2C is an angle between the transmission axis direction D1C of the lower polarizing plate 52 and the initial alignment direction D3C of the upper alignment film 74. It is preferable that the angle θ _2C is not less than 85 degrees and not more than 95 degrees. The angle θ _3C is an angle formed between the transmission axis direction D1C of the lower polarizing plate 52 and the transmission axis direction D4C of the middle polarizing plate 54. The angle θ _3C is preferably 85 degrees or more and 95 degrees or less. The angle θ _7C is an angle between the transmission axis direction D1C of the lower polarizing plate 52 and the initial alignment directions D5C and D6C of the image display panel 30. Angle θ _7C is preferably not less than 85 degrees and not more than 95 degrees. The angle θ _8C is the angle between the transmission axis direction D1C of the lower polarizing plate 52 and the transmission axis direction D7C of the upper polarizing plate 58. The angle θ _7C is preferably equal to or greater than 0 degree and equal to or less than 10 degrees.

The angle θ _{4C in} FIG. 24 is the angle between the initial alignment direction D2C of the lower alignment film 89 and the initial alignment direction D3C of the upper alignment film 74. The angle θ _4C is preferably 90 degrees or more and 100 degrees or less. The angle θ _5C is an angle formed between the initial alignment direction D2C of the lower alignment film 89 and the transmission axis direction D4C of the middle polarizing plate 54. Angle θ _5C is preferably 90 degrees or more and 100 degrees or less. The angle θ _9C is an angle between the initial alignment direction D2C of the lower alignment film 89 and the initial alignment directions D5C and D6C of the image display panel 30. The angle θ _9C is preferably 90 degrees or more and 100 degrees or less. The angle θ _10C is an angle between the initial alignment direction D2C of the lower alignment film 89 and the transmission axis direction D7C of the upper polarizing plate 58. The angle θ _10C is preferably equal to or greater than 0 degree and equal to or less than 5 degrees.

The angle θ _{6C in} FIG. 24 is the angle between the initial alignment direction D3C of the upper alignment film 74 and the transmission axis direction D4C of the middle polarizer 54. The angle θ _6C is preferably equal to or greater than 0 degrees and equal to or less than 5 degrees. The angle θ _11C is an angle between the initial alignment direction D3C of the upper alignment film 74 and the initial alignment directions D5C and D6C of the image display panel 30. The angle θ _11C is preferably equal to or greater than 0 degree and equal to or less than 5 degrees. The angle θ _12C is an angle between the initial alignment direction D3C of the upper alignment film 74 and the transmission axis direction D7C of the upper polarizing plate 58. The angle θ _12C is preferably 90 degrees or more and 100 degrees or less.

The angle θ _{13C in} FIG. 24 is an angle between the transmission axis direction D4C of the middle polarizing plate 54 and the initial alignment directions D5C and D6C of the image display panel 30. The angle θ _13C is preferably equal to or greater than 0 degree and equal to or less than 5 degrees. The angle θ _14C is an angle between the transmission axis direction D4C of the middle polarizing plate 54 and the transmission axis direction D7C of the upper polarizing plate 58. The angle θ _14C is preferably 90 degrees or more and 100 degrees or less.

The angle theta _15C of FIG. 24 is an angle formed between the transmission axis direction D7C initial alignment direction D5C, D6C the upper polarizing plate 58 of the image display panel 30. The angle θ _15C is preferably 90 degrees or more and 100 degrees or less.

The display device 1C according to the second modification is similar to the display device 1B according to the second embodiment in that the transmission axis direction D1C of the lower polarizing plate 52 and the initial alignment direction D2C of the lower alignment film 89 of the light control panel 80 are different. By not being parallel and not orthogonal, it is possible to suppress a decrease in luminance.

FIG. 25 is a graph showing an example of the luminance of the display device according to the second modification. A line segment L1Z2 in FIG. 25 indicates the luminance for each viewing angle of the display device according to the second comparative example. The line segment L1C indicates the luminance for each viewing angle of the display device 1C according to the second modification. As shown in FIG. 25, the luminance of the display device 1C according to the second modification is higher than the luminance of the display device of the second comparative example.

FIG. 26 is a graph showing an example of the contrast of the display device according to the second modification. The line segment L2Z2 in FIG. 26 is the contrast for each viewing angle of the display device according to the second comparative example, and the line segment L2C is the contrast for each viewing angle of the display device 1C according to the second modification. As shown in FIG. 26, the display device 1C according to the second modification can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

(Third embodiment)
Next, a third embodiment will be described. The display device 1C according to the third embodiment differs from the second embodiment in the transmission axis direction of the middle polarizer 54, the initial orientation direction of the image display panel 30, and the initial orientation direction of the upper polarizer 58. . In the third embodiment, description of portions having the same configuration as the second embodiment will be omitted.

FIG. 27 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to the third embodiment. As shown in FIG. 27, in the third embodiment, the initial alignment direction of the lower alignment film 89 is set such that the twisting direction of the liquid crystal element LC of the light control panel 80 is the clockwise direction T1 on the XY plane. D2 and the initial alignment direction D3 of the upper alignment film 74 are set. That is, the twist direction of the liquid crystal element LC in the third embodiment is the same as that in the second embodiment.

透過 The transmission axis direction D1D of the lower polarizing plate 52 in the third embodiment is the same as the transmission axis direction D1B in the second embodiment. The initial alignment direction D2D of the lower alignment film 89 of the light control panel 80 according to the third embodiment is the same as the initial alignment direction D2B in the second embodiment. The initial alignment direction D3D of the upper alignment film 74 of the light control panel 80 according to the third embodiment is the same as the initial alignment direction D3B in the second embodiment.

On the other hand, in the middle polarizing plate 54 in the third embodiment, the transmission axis direction D4D of the liquid crystal element LC of the light control panel 80 is twisted with respect to the reference orthogonal axis AX2 on the XY plane (as viewed from the Z direction). The transmission axis direction D1D of the lower polarizer 52 is inclined in the same direction as the reference axis AX1. Therefore, in the third embodiment, the transmission axis direction D4D of the middle polarizing plate 54 is inclined in the clockwise direction T1 with respect to the reference orthogonal axis AX2. In the transmission axis direction D4D of the middle polarizing plate 54, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1. That is, in the transmission axis direction D4D, the inclination angle with respect to the reference orthogonal axis AX2 is smaller than 45 degrees.

In the third embodiment, the lower alignment film 29 of the image display panel 30 has an initial alignment direction D5D of the light control panel 80 with respect to the reference orthogonal axis AX2 in the XY plane (as viewed from the Z direction). The liquid crystal element LC is tilted in the same direction as the twisting direction, in other words, in the same direction as the transmission axis direction D1D of the lower polarizing plate 52 is tilted with respect to the reference axis AX1. Therefore, in the third embodiment, the initial alignment direction D5D of the lower alignment film 29 is inclined in the clockwise direction T1 with respect to the reference orthogonal axis AX2. In the initial alignment direction D5D of the lower alignment film 29, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1. That is, in the transmission axis direction D4B, the inclination angle with respect to the reference orthogonal axis AX2 is smaller than 45 degrees. In the upper alignment film 32 of the image display panel 30 in the third embodiment, the initial alignment direction D6D is along the initial alignment direction D5D of the lower alignment film 29.

In the third embodiment, the upper polarizing plate 58 is configured such that, in the XY plane (as viewed from the Z direction), the transmission axis direction D7D is twisted with respect to the reference axis AX1 of the liquid crystal element LC of the light control panel 80. In other words, the transmission axis direction D1D of the lower polarizing plate 52 is inclined in the opposite direction to the reference axis AX1. Therefore, in the third embodiment, the transmission axis direction D7D of the upper polarizing plate 58 is inclined in the counterclockwise direction T2 with respect to the reference axis AX1. In the transmission axis direction D7D of the upper polarizing plate 58, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2. That is, in the transmission axis direction D4B, the inclination angle with respect to the reference axis AX1 is smaller than 45 degrees.

Next, the angles of the transmission axis direction and the initial alignment direction will be described. The magnitude of the angle at which the transmission axis direction D4D of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2, the magnitude of the angle at which the initial orientation directions D5D and D6D of the image display panel 30 are inclined with respect to the reference orthogonal axis AX2, and The magnitude of the angle at which the transmission axis direction D7D of 58 is inclined with respect to the reference axis AX1 is the same as in the second embodiment.

FIG. 28 is a diagram illustrating the relationship between the transmission axis direction and the initial alignment direction in the third embodiment. The angle θ _{1D in} FIG. 28 is an angle between the transmission axis direction D1D of the lower polarizing plate 52 and the initial alignment direction D2D of the lower alignment film 89. That is, the initial alignment direction D2D of the lower alignment film 89 is counterclockwise T2 with respect to the transmission axis direction D1D of the lower polarizer 52, that is, in the direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80, It is inclined by the angle θ _1D . The angle θ _1D is preferably greater than 0 degrees and 10 degrees or less. The angle θ _2D is the angle between the transmission axis direction D1D of the lower polarizing plate 52 and the initial alignment direction D3D of the upper alignment film 74. It is preferable that the angle θ _2D is not less than 85 degrees and not more than 95 degrees. The angle θ _3D is an angle between the transmission axis direction D1D of the lower polarizing plate 52 and the transmission axis direction D4D of the middle polarizing plate 54. It is preferable that the angle θ _3D is not less than 85 degrees and not more than 95 degrees. The angle θ _7D is an angle between the transmission axis direction D1D of the lower polarizing plate 52 and the initial alignment directions D5D and D6D of the image display panel 30. It is preferable that the angle θ _7D is not less than 85 degrees and not more than 95 degrees. The angle θ _8D is the angle between the transmission axis direction D1D of the lower polarizing plate 52 and the transmission axis direction D7D of the upper polarizing plate 58. The angle θ _8D is preferably equal to or greater than 0 degrees and equal to or less than 10 degrees.

The angle θ _{4D in} FIG. 28 is an angle formed between the initial alignment direction D2D of the lower alignment film 89 and the initial alignment direction D3D of the upper alignment film 74. The angle θ _4D is preferably 80 degrees or more and 90 degrees or less. The angle θ _5D is an angle formed between the initial alignment direction D2D of the lower alignment film 89 and the transmission axis direction D4D of the middle polarizing plate 54. It is preferable that the angle _θ5D is not less than 80 degrees and not more than 90 degrees. The angle θ _9D is an angle between the initial alignment direction D2D of the lower alignment film 89 and the initial alignment directions D5D and D6D of the image display panel 30. It is preferable that the angle θ _9D is not less than 80 degrees and not more than 90 degrees. The angle θ _10D is an angle between the initial alignment direction D2D of the lower alignment film 89 and the transmission axis direction D7D of the upper polarizing plate 58. The angle θ _10D is preferably equal to or greater than 0 degree and equal to or less than 5 degrees.

The angle θ _{6D in} FIG. 28 is the angle between the initial alignment direction D3D of the upper alignment film 74 and the transmission axis direction D4D of the middle polarizer 54. The angle θ _6D is preferably equal to or greater than 0 degree and equal to or less than 5 degrees. The angle θ _11D is an angle between the initial alignment direction D3D of the upper alignment film 74 and the initial alignment directions D5D and D6D of the image display panel 30. It is preferable that the angle θ _11D is not less than 0 degrees and not more than 5 degrees. The angle θ _12D is an angle formed between the initial alignment direction D3D of the upper alignment film 74 and the transmission axis direction D7D of the upper polarizing plate 58. The angle θ _12D is preferably 80 degrees or more and 90 degrees or less.

The angle θ _{13D in} FIG. 28 is an angle between the transmission axis direction D4D of the middle polarizing plate 54 and the initial alignment directions D5D and D6D of the image display panel 30. It is preferable that the angle θ _13D is not less than 0 degrees and not more than 5 degrees. The angle θ _14D is an angle between the transmission axis direction D4D of the middle polarizing plate 54 and the transmission axis direction D7D of the upper polarizing plate 58. The angle θ _14D is preferably 80 degrees or more and 90 degrees or less.

The angle θ _{15D in} FIG. 28 is an angle formed between the initial alignment directions D5D and D6D of the image display panel 30 and the transmission axis direction D7D of the upper polarizing plate 58. The angle θ _15D is preferably 80 degrees or more and 90 degrees or less.

As described above, the display device 1D according to the third embodiment includes the transmission axis direction D1D of the lower polarizing plate 52 and the initial alignment direction D2D of the lower alignment film 89 of the light control panel 80, as in the second embodiment. Are not parallel and not orthogonal to each other, it is possible to suppress a decrease in luminance.

Furthermore, in the third embodiment, the transmission axis direction D4D of the middle polarizer 54 is inclined in one of clockwise and counterclockwise directions (here, clockwise direction T1) with respect to the reference orthogonal axis AX2. ing. In this way, the display device 1D can appropriately suppress the decrease in luminance by tilting the transmission axis direction D4B of the middle polarizing plate 54 in the same direction as the transmission axis direction D1 of the lower polarizing plate 52.

The initial alignment directions D5D and D6D of the image display panel 30 are inclined in one of clockwise and counterclockwise directions (here, clockwise direction T1) with respect to the reference orthogonal axis AX2. The transmission axis direction D7D of 58 is inclined to the other side (here, counterclockwise direction T2) of the clockwise direction and the counterclockwise direction with respect to the reference axis AX1. As described above, the display device 1D can appropriately suppress the decrease in luminance by tilting the initial alignment directions D5D and D6D of the image display panel 30 and the transmission axis direction D7D of the upper polarizing plate 58.

FIG. 29 is a graph showing an example of the luminance of the display device according to the third embodiment. A line segment L1Z1 in FIG. 29 indicates the luminance at each viewing angle of the display device according to the first comparative example. The line segment L1D indicates the luminance for each viewing angle of the display device 1D according to the third embodiment. As shown in FIG. 29, the brightness of the display device 1D according to the third embodiment is higher than the brightness of the display device of the first comparative example.

FIG. 30 is a graph showing an example of the contrast of the display device according to the third embodiment. A line segment L2Z1 in FIG. 30 is a contrast for each viewing angle of the display device according to the first comparative example, and a line segment L2D is a contrast for each viewing angle of the display device 1C according to the third embodiment. As shown in FIGS. 29 and 30, the display device 1C according to the third embodiment can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

(Third Modification)
Next, a third modification which is a modification of the third embodiment will be described. The display device 1E according to the third modification differs from the third embodiment in the twist direction of the liquid crystal element LC. In the third modified example, description of portions having the same configuration as the third embodiment will be omitted.

FIG. 31 is a schematic diagram illustrating a transmission axis direction and an initial alignment direction according to a third modification. As shown in FIG. 31, in the third modification, the initial alignment of the lower alignment film 89 is performed so that the twisting direction of the liquid crystal element LC of the light control panel 80 is the counterclockwise direction T2 on the XY plane. The direction D2E and the initial alignment direction D3E of the upper alignment film 74 are set.

As shown in FIG. 31, the transmission axis direction D1E of the lower polarizing plate 52 in the third modification is the same as the transmission axis direction D1C (see FIG. 23) in the second modification. The initial alignment direction D2E of the lower alignment film 89 of the light control panel 80 according to the third modification is the same as the initial alignment direction D2C (see FIG. 23) in the second modification. The initial alignment direction D3E of the upper alignment film 74 of the light control panel 80 according to the third modification is the same as the initial alignment direction D3C (see FIG. 23) in the second modification. That is, in the third modified example, the twisting direction of the liquid crystal element LC of the light control panel 80 is opposite to that of the third embodiment, so that the tilt direction of the transmission axis direction D1E of the lower polarizing plate 52 and the lower alignment film The inclination direction of the initial alignment direction D2E of 89 and the inclination direction of the initial alignment direction D3E of the upper alignment film 74 are also opposite to those in the third embodiment.

Further, the transmission axis direction D4E of the middle polarizing plate 54 in the third modification is a twist direction of the liquid crystal element LC of the light control panel 80 with respect to the reference orthogonal axis AX2 on the XY plane (as viewed from the Z direction). , In other words, in the direction opposite to the direction in which the transmission axis direction D1E of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the third modified example, the transmission axis direction D4E of the middle polarizing plate 54 is inclined in the clockwise direction T1 with respect to the reference orthogonal axis AX2. That is, the transmission axis direction D4E of the middle polarizer 54 is inclined in the clockwise direction T1 as in the third embodiment, but the twist direction of the liquid crystal element LC of the light control panel 80 and the transmission axis direction of the lower polarizer 52. The direction of inclination relative to the direction of inclination of D1E is opposite to that of the third embodiment. In the transmission axis direction D4E of the middle polarizing plate 54, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1.

In the third modification, the initial alignment direction D5E of the lower alignment film 29 of the image display panel 30 is equal to the liquid crystal of the light control panel 80 with respect to the reference orthogonal axis AX2 on the XY plane (as viewed from the Z direction). The element LC is tilted in a direction opposite to the twisting direction, in other words, in a direction opposite to the direction in which the transmission axis direction D1E of the lower polarizing plate 52 is tilted with respect to the reference axis AX1. Therefore, in the third modification, the initial alignment direction D5E of the lower alignment film 29 is inclined in the clockwise direction T1 with respect to the reference orthogonal axis AX2. That is, the initial alignment direction D5E of the lower alignment film 29 is inclined in the clockwise direction T1 as in the third embodiment, but the twisting direction of the liquid crystal element LC of the light control panel 80 and the transmission axis direction of the lower polarizing plate 52. The direction of inclination relative to the direction of inclination of D1E is opposite to that of the third embodiment. In the initial alignment direction D5E of the lower alignment film 29, the vector component in the direction along the reference orthogonal axis AX2 is higher than the vector component in the direction along the reference axis AX1. Further, the initial alignment direction D6E of the upper alignment film 32 of the image display panel 30 in the third modification is along the initial alignment direction D5E of the lower alignment film 29.

Further, the transmission axis direction D7E of the upper polarizing plate 58 in the third embodiment is the twist direction of the liquid crystal element LC of the light control panel 80 with respect to the reference axis AX1 on the XY plane (as viewed from the Z direction). In other words, in other words, in the same direction as the direction in which the transmission axis direction D1C of the lower polarizing plate 52 is inclined with respect to the reference axis AX1. Therefore, in the third modification, the transmission axis direction D7E of the upper polarizing plate 58 is inclined in the counterclockwise direction T2 with respect to the reference axis AX1. In other words, the transmission axis direction D7E of the upper polarizing plate 58 is inclined in the counterclockwise direction T2 as in the third embodiment, but the twisting direction of the liquid crystal element LC of the light control panel 80 and the transmission axis direction of the lower polarizing plate 52. The direction of inclination of the direction D1E relative to the direction of inclination is opposite to that of the third embodiment. In the transmission axis direction D7E of the upper polarizing plate 58, the vector component in the direction along the reference axis AX1 is higher than the vector component in the direction along the reference orthogonal axis AX2.

Next, the angles of the transmission axis direction and the initial alignment direction will be described. The angle at which the transmission axis direction D4E of the middle polarizing plate 54 is inclined with respect to the reference orthogonal axis AX2, the angle at which the initial alignment directions D5E and D6E of the image display panel 30 are inclined with respect to the reference orthogonal axis AX2, The magnitude of the angle at which the transmission axis direction D7E of 58 inclines with respect to the reference axis AX1 is the same as in the third embodiment.

FIG. 32 is a diagram showing the relationship between the transmission axis direction and the initial alignment direction in the third modification. The angle θ _{1E in} FIG. 24 is the angle between the transmission axis direction D1E of the lower polarizing plate 52 and the initial alignment direction D2E of the lower alignment film 89. That is, the initial alignment direction D2E of the lower alignment film 89 is angled with respect to the transmission axis direction D1E of the lower polarizing plate 52 in the clockwise direction T1, that is, in the direction opposite to the twisting direction of the liquid crystal element LC of the light control panel 80. It is inclined by θ _1E . It is preferable that the angle θ _1E is larger than 0 degree and equal to or smaller than 10 degrees. The angle θ _2E is an angle between the transmission axis direction D1E of the lower polarizing plate 52 and the initial alignment direction D3E of the upper alignment film 74. It is preferable that the angle θ _2E is not less than 85 degrees and not more than 95 degrees. The angle θ _3E is an angle between the transmission axis direction D1E of the lower polarizing plate 52 and the transmission axis direction D4E of the middle polarizing plate 54. The angle θ _3E is preferably 80 degrees or more and 90 degrees or less. The angle θ _7E is an angle between the transmission axis direction D1E of the lower polarizing plate 52 and the initial alignment directions D5E and D6E of the image display panel 30. Angle θ _7E is preferably 80 degrees or more and 90 degrees or less. The angle θ _8E is an angle between the transmission axis direction D1E of the lower polarizing plate 52 and the transmission axis direction D7E of the upper polarizing plate 58. The angle θ _8E is preferably equal to or greater than 0 degrees and equal to or less than 5 degrees.

The angle θ _{4E in} FIG. 32 is an angle formed between the initial alignment direction D2E of the lower alignment film 89 and the initial alignment direction D3E of the upper alignment film 74. The angle θ _4E is preferably 90 degrees or more and 100 degrees or less. The angle θ _5E is an angle formed between the initial alignment direction D2E of the lower alignment film 89 and the transmission axis direction D4E of the middle polarizing plate 54. Angle θ _5E is preferably not less than 85 degrees and not more than 95 degrees. The angle θ _9E is an angle between the initial alignment direction D2E of the lower alignment film 89 and the initial alignment directions D5E and D6E of the image display panel 30. It is preferable that the angle θ _9E is not less than 85 degrees and not more than 95 degrees. The angle θ _10E is an angle between the initial alignment direction D2E of the lower alignment film 89 and the transmission axis direction D7E of the upper polarizing plate 58. The angle θ _10E is preferably equal to or greater than 0 degree and equal to or less than 10 degrees.

The angle θ _{6E in} FIG. 32 is an angle between the initial alignment direction D3E of the upper alignment film 74 and the transmission axis direction D4E of the middle polarizer 54. The angle θ _6E is preferably equal to or greater than 0 degrees and equal to or less than 10 degrees. The angle θ _11E is an angle between the initial alignment direction D3E of the upper alignment film 74 and the initial alignment directions D5E and D6E of the image display panel 30. It is preferable that the angle _θ11E is not less than 0 degree and not more than 10 degrees. The angle θ _12E is an angle formed between the initial alignment direction D3E of the upper alignment film 74 and the transmission axis direction D7E of the upper polarizing plate 58. The angle θ _12E is preferably equal to or greater than 85 degrees and equal to or less than 95 degrees.

The angle θ _{13E in} FIG. 32 is an angle between the transmission axis direction D4E of the middle polarizing plate 54 and the initial alignment directions D5E and D6E of the image display panel 30. The angle θ _13E is preferably equal to or more than 0 degree and equal to or less than 5 degrees. The angle θ _14E is an angle formed between the transmission axis direction D4E of the middle polarizing plate 54 and the transmission axis direction D7E of the upper polarizing plate 58. The angle θ _14E is preferably 80 degrees or more and 90 degrees or less.

The angle theta _15E of FIG. 32 is an angle formed between the transmission axis direction D7E initial alignment direction D5E, D6E the upper polarizing plate 58 of the image display panel 30. The angle θ _15E is preferably 80 degrees or more and 90 degrees or less.

The display device 1E according to the third modification is similar to the display device 1D according to the third embodiment in that the transmission axis direction D1E of the lower polarizing plate 52 and the initial alignment direction D2E of the lower alignment film 89 of the light control panel 80 are different. By not being parallel and not orthogonal, it is possible to suppress a decrease in luminance.

FIG. 33 is a graph showing an example of the luminance of the display device according to the third modification. A line segment L1Z2 in FIG. 33 indicates the luminance at each viewing angle of the display device according to the second comparative example. The line segment L1E indicates the luminance for each viewing angle of the display device 1E according to the third modification. As shown in FIG. 33, the luminance of the display device 1E according to the third modification is higher than the luminance of the display device of the second comparative example.

FIG. 34 is a graph illustrating an example of the contrast of the display device according to the third modification. The line segment L2Z2 in FIG. 34 is the contrast for each viewing angle of the display device according to the second comparative example, and the line segment L2E is the contrast for each viewing angle of the display device 1E according to the third modification. As shown in FIGS. 33 and 34, the display device 1E according to the third modification can increase the luminance while maintaining the contrast by tilting the transmission axis and the initial alignment direction.

In addition, it is understood that other operational effects brought about by the aspects described in the present embodiment are clear from the description of the present specification, or those that can be appropriately conceived by those skilled in the art are naturally brought about by the present invention. .

Reference Signs List 1 display device 10 signal processing unit 20

display unit

29, 89 lower alignment film 30

image display panel

32, 74 upper alignment film 50 light source unit 52 lower polarizing plate 54 middle polarizing plate 56 adhesive layer 58 upper polarizing plate 70 light control unit 80 light control Light panel 81 First electrode 82 Second electrode D1, D4, D7 Transmission axis direction D2, D3, D5, D6 Initial alignment direction LC1, LC2 Liquid crystal layer

Claims

An image display panel having a plurality of pixels,
A light source unit provided on the back side of the image display panel,
The lower alignment film provided between the image display panel and the light source unit, the lower alignment film on the light source unit side, the plurality of first electrodes arranged in a matrix, and the lower alignment film are opposed to the lower alignment film. An upper alignment film, a second electrode, and a liquid crystal layer provided on the image display panel side; and light emitted from the light source unit by a voltage applied between the first electrode and the second electrode. In the liquid crystal layer, a light control panel configured to be able to transmit to the back side of the image display panel while changing transmittance,
A lower polarizing plate provided between the dimming panel and the light source unit,
The transmission axis of the lower polarizing plate is not parallel to the initial alignment direction of the lower alignment film, and is along a direction that is not orthogonal.
Display device.
The transmission axis of the lower polarizing plate is inclined to one of clockwise and counterclockwise with respect to a reference axis along a predetermined direction, and the initial alignment direction of the lower alignment film is the reference axis. The display device according to claim 1, wherein the display device is inclined to the other side of clockwise and counterclockwise with respect to.
The display device according to claim 2, wherein the initial alignment direction of the upper alignment film is inclined toward the one of clockwise and counterclockwise with respect to a reference orthogonal axis orthogonal to the reference axis.
The initial alignment direction of the lower alignment film and the initial alignment direction of the upper alignment film are different from each other when the liquid crystal element in the liquid crystal layer does not apply a voltage to the first electrode and the second electrode. 4. The display device according to claim 2, wherein the display device is configured to be twisted in one of the clockwise direction and the counterclockwise direction from the plate side toward the image display panel side. 5.
A middle polarizing plate provided between the light control panel and the image display panel,
An upper polarizing plate provided on the front side opposite to the back side of the image display panel;
The display device according to any one of claims 2 to 4, further comprising:
The display device according to claim 5, wherein the transmission axis of the middle polarizer is along a reference orthogonal axis orthogonal to the reference axis.
6. The display device according to claim 5, wherein an initial orientation direction of the image display panel is along a reference orthogonal axis orthogonal to the reference axis, and a transmission axis of the upper polarizing plate is along the reference axis.
6. The display device according to claim 5, wherein the transmission axis of the middle polarizer is inclined to the other side of clockwise and counterclockwise with respect to a reference orthogonal axis orthogonal to the reference axis. 7.
The initial orientation direction of the image display panel is inclined to the other side of clockwise and counterclockwise with respect to a reference orthogonal axis orthogonal to the reference axis, and the transmission axis of the upper polarizing plate is The display device according to claim 5, wherein the display device is inclined to the one of the clockwise direction and the counterclockwise direction with respect to a reference axis.
6. The display device according to claim 5, wherein the transmission axis of the middle polarizer is inclined to the one of clockwise and counterclockwise with respect to a reference orthogonal axis orthogonal to the reference axis. 7.
The initial orientation direction of the image display panel is inclined to the one side of clockwise and counterclockwise with respect to a reference orthogonal axis orthogonal to the reference axis, and the transmission axis of the upper polarizing plate is The display device according to claim 5, wherein the display device is inclined to the other side of the clockwise direction and the counterclockwise direction with respect to a reference axis.