TWI851123B - Anti-peeping display device - Google Patents

Abstract

An anti-peeping display device including a display panel and a view-angle control module, which are stacked, is provided. The view-angle control module includes a first polarization layer, a first liquid crystal layer, a second polarization layer, a second liquid crystal layer and a third polarization layer, which are sequentially stacked. The phase retardations of the first liquid crystal layer and the second liquid crystal layer are within 700 nm to 1200 nm.

Description

Anti-sight display device

The present invention relates to a display device, in particular to a display device with anti-peeping function.

Generally speaking, in order to allow multiple viewers to watch together, display devices usually have a wide viewing angle display effect. However, in some situations or occasions, it is necessary to limit the visual direction. For example, the demand for anti-peeping screens for cars has gradually increased in recent years, mainly because it is expected that while the co-pilot passenger enjoys the audio-visual facilities, the driver's viewing angle (i.e., driver anti-peeping) is shielded to avoid affecting driving safety. In other words, an asymmetric viewing angle is required. In addition, when there is no concern about driving safety, it is hoped that the driver and the co-pilot passenger can watch the screen at the same time. However, the existing anti-peeping switching technologies on the market are all symmetrical viewing angles, and it is impossible to limit the brightness of certain specific viewing angles.

The present invention provides an anti-peeping display device with good anti-peeping capability.

According to an embodiment of the present invention, a peep-proof display device is provided, including a display panel and a viewing angle control module. The viewing angle control module includes a first polarizing layer, a first liquid crystal layer, a second polarizing layer, a second liquid crystal layer and a third polarizing layer stacked in sequence, wherein the phase delay of the first liquid crystal layer and the second liquid crystal layer falls within the range of 700nm to 1200nm. The viewing angle control module has a first side close to the first polarizing layer and a second side close to the third polarizing layer, and the display panel is configured on the first side of the viewing angle control module or on the second side of the viewing angle control module.

Based on the above, the anti-peeping display device provided by the embodiment of the present invention uses a dual TN liquid crystal structure to provide good anti-peeping capabilities. And the phase delay of the dual TN liquid crystal layer falls within the range of 700nm to 1200nm, so that the brightness and chromaticity at the normal viewing angle will not differ significantly between the anti-peeping mode and the sharing mode.

In order to make the above features and advantages of the present invention more clearly understood, the following is a detailed description of the embodiments with the accompanying drawings.

Referring to FIG. 1 , an anti-peeping display device according to an embodiment of the present invention is shown. The anti-peeping display device 100 includes a display panel 101, a viewing angle control module 102, and a quarter wave plate 103. The viewing angle control module 102 includes a first polarizing layer P1, a first liquid crystal layer LC1, a second polarizing layer P2, a second liquid crystal layer LC2, and a third polarizing layer P3 stacked in sequence, wherein the liquid crystal molecules in the first liquid crystal layer LC1 and the second liquid crystal layer LC2 are twisted nematic liquid crystals (TN liquid crystals).

It should be noted that the anti-penetration display device 100 is placed on the X-Y plane, wherein the +X direction has an azimuth angle of 0 degrees, the +Y direction has an azimuth angle of 90 degrees, the -X direction has an azimuth angle of 180 degrees, and the -Y direction has an azimuth angle of 270 degrees. The +Z direction has a viewing angle of 0 degrees, i.e., the normal viewing angle direction.

It should be particularly noted that each embodiment of the present invention utilizes the grayscale viewing angle asymmetry of the TN liquid crystal in the viewing angle control module when driven to achieve an asymmetric viewing angle display mode (hereinafter referred to as the anti-peeping mode). Moreover, when the TN liquid crystal is not driven, the display mode is restored to a viewing angle symmetric sharing mode.

In some embodiments of the present invention, the phase delay of the first liquid crystal layer LC1 and the second liquid crystal layer LC2 are both within the range of 700nm to 1200nm to maintain the brightness at the normal viewing angle and avoid excessive brightness attenuation when switching to the anti-peeping mode. Specifically, please refer to Figure 3 and Table 1 to understand the effect of the phase delay of the TN liquid crystal layer of the viewing angle control module 102 on the brightness and chromaticity of the transmitted light, wherein Figure 3 is a curve diagram showing the relationship between the phase delay of the liquid crystal layer and the transmittance of different color lights. In the comparison example shown in Table 1, the phase delay of the TN liquid crystal layer is 477nm, corresponding to the first-order transmittance maximum value of the green light band 550nm. In the first embodiment of the present invention shown in Table 1, the phase delay of the TN liquid crystal layer is 872nm, corresponding to the second-order maximum transmittance of 450nm in the blue light band. In the second embodiment of the present invention shown in Table 1, the phase delay of the TN liquid crystal layer is 1066nm, corresponding to the second-order maximum transmittance of 550nm in the green light band. Table 1 lists the above-mentioned comparison examples and the front-viewing chromaticity values (x value, y value) and brightness values (Y value) in the sharing mode and the anti-peeping mode in the first and second embodiments of the present invention.

As shown in Table 1, the display device in the comparative example has a front-viewing angle brightness of 127.3 nit in the anti-peeping mode, which is significantly lower than the front-viewing angle brightness of 241.2 nit in the sharing mode. In contrast, the front-viewing angle brightness of the first embodiment of the present invention in the anti-peeping mode is 204.6 nit, which is only slightly lower than the front-viewing angle brightness of 217.2 nit in the sharing mode. The front-viewing angle brightness of the second embodiment of the present invention in the anti-peeping mode is 200.4 nit, which is only slightly lower than the front-viewing angle brightness of 241.0 nit in the sharing mode.

In addition, as shown in Table 1, the chromaticity difference of the comparison example in the sharing mode and the anti-peeping mode is △(x,y)=(0.064,0.086). In contrast, the chromaticity difference of the first embodiment of the present invention in the sharing mode and the anti-peeping mode is △(x,y)=(0.007,0.010), and the chromaticity difference of the second embodiment of the present invention in the sharing mode and the anti-peeping mode is △(x,y)=(0.018,0.018). That is to say, compared with the comparison example, in the first embodiment and the second embodiment of the present invention, the chromaticity difference of the normal viewing angle in the sharing mode and the anti-peeping mode is smaller, and the display device has better chromaticity performance.

Therefore, according to some embodiments of the present invention, the phase delay of the first liquid crystal layer LC1 and the second liquid crystal layer LC2 are both configured within the range of 872nm±100nm. According to some embodiments of the present invention, the phase delay of the first liquid crystal layer LC1 and the second liquid crystal layer LC2 are both configured within the range of 1066nm±100nm, so that the brightness and chromaticity performance at the front viewing angle are good, and the TN liquid crystal layer with the above phase delay also meets the requirement that the brightness at a side viewing angle of 45 degrees is less than 1% of the brightness at the front viewing angle.

Please refer to Figure 1 again. The viewing angle control module 102 has a first side S1 close to the first polarizing layer P1 and a second side S2 close to the third polarizing layer P3. In this embodiment, the display panel 101 is disposed on the first side S1 of the viewing angle control module 102, that is, the display panel 101 is disposed below the viewing angle control module 102, and the quarter wave plate 103 is sandwiched between the display panel 101 and the viewing angle control module 102.

The first polarizing layer P1 has a first transmission direction T1, the first liquid crystal layer LC1 has a first alignment direction D1 and a second alignment direction D2, the second polarizing layer P2 has a second transmission direction T2, the second liquid crystal layer LC2 has a third alignment direction D3 and a fourth alignment direction D4, and the third polarizing layer P3 has a third transmission direction T3. In this embodiment, the second transmission direction T2 is perpendicular to the first transmission direction T1 and the third transmission direction T3. The direction limitation of the first alignment direction D1, the second alignment direction D2, the third alignment direction D3 and the fourth alignment direction D4 can be achieved by configuring multiple alignment layers (not shown). The first alignment direction D1 and the second alignment direction D2 can achieve a good rotation effect for the liquid crystal molecules of the first liquid crystal layer LC1. Similarly, the third alignment direction D3 and the fourth alignment direction D4 can achieve a good rotation effect for the liquid crystal molecules of the second liquid crystal layer LC2.

In the embodiment shown in FIG. 1 , the display panel 101 is a self-luminous display panel, such as an organic light-emitting diode display panel or a micro-luminescent diode display panel, and the quarter-wave plate 103 is disposed between the self-luminous display panel 101 and the viewing angle control module 102, wherein the slow axis of the quarter-wave plate 103 is parallel to the Y direction (i.e., has an azimuth angle of 90 degrees) and is 45 degrees from the first transmission direction T1. Accordingly, when ambient light passes through the viewing angle control module 102, the linear polarized light passing through the first polarizing layer P1 downward will be formed into left-handed light/right-handed light after passing through the quarter-wave plate 103. This left-handed light/right-handed light will be formed into right-handed light/left-handed light after being reflected by the metal structure in the self-luminous display panel 101, and will be formed into linear polarized light perpendicular to the first penetration direction T1 after passing through the quarter-wave plate 103 upward, and thus will be shielded by the first polarizing layer P1. In other words, by configuring the quarter-wave plate 103 sandwiched between the self-luminous display panel 101 and the viewing angle control module 102, the reflection of ambient light can be effectively avoided.

The liquid crystal molecules in the first liquid crystal layer LC1 and the second liquid crystal layer LC2 of this embodiment are TN liquid crystals. The anti-peeping display device 100 uses the grayscale viewing angle asymmetry of the TN liquid crystal when driven to achieve an anti-peeping mode with an asymmetric viewing angle. When the TN liquid crystal is not driven, the display mode of the anti-peeping display device 100 is restored to a sharing mode with a symmetric viewing angle.

Furthermore, since the emitted light of the self-luminous display panel 101 itself has no obvious polarization state, compared with the situation where the upper polarizer of the liquid crystal display panel will restrict the viewing angle direction, the first penetration direction T1 in this embodiment is configured to have an azimuth angle of 45 degrees. Accordingly, the anti-peeping efficiency of the left viewing angle (i.e., 180-degree azimuth angle) can be greatly improved. However, the present invention is not limited to the above-mentioned left and right anti-peeping. Specifically, since the emitted light of the self-luminous display panel 101 itself has no obvious polarization state, the anti-peeping viewing angle is not limited to the above-mentioned left and right viewing angles, but the direction of the first penetration direction T1 can be changed according to needs, so that it has any azimuth angle, and the anti-peeping viewing angle can be freely changed.

In the embodiment shown in FIG. 1 , the first alignment direction D1 of the first liquid crystal layer LC1 is parallel to the third alignment direction D3 of the second liquid crystal layer LC2, and the second alignment direction D2 of the first liquid crystal layer LC1 is parallel to the fourth alignment direction D4 of the second liquid crystal layer LC2. The second transmission direction T2 is parallel to the second alignment direction D2 of the first liquid crystal layer LC1 and perpendicular to the third alignment direction D3 of the second liquid crystal layer LC2. The first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in E-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in O-mode.

In order to fully illustrate the various embodiments of the present invention, other embodiments of the present invention will be described below. It must be noted that the following embodiments use the component numbers and some contents of the previous embodiments, where the same numbers are used to represent the same or similar components, and the description of the same technical content is omitted. For the description of the omitted parts, please refer to the previous embodiments, and the following embodiments will not be repeated.

Next, please refer to FIG. 2, which shows an anti-peeping display device according to an embodiment of the present invention. The anti-peeping display device 200 includes a display panel 101, a viewing angle control module 102 and a quarter wave plate 103. The viewing angle control module 102 includes a first polarizing layer P1, a first liquid crystal layer LC1, a second polarizing layer P2, a second liquid crystal layer LC2 and a third polarizing layer P3 stacked in sequence. The display panel 101 is disposed on the first side S1 of the viewing angle control module 102, but the present invention is not limited thereto. In some embodiments, the display panel 101 is disposed on the second side S2 of the viewing angle control module 102.

The anti-penetration display device 200 of this embodiment is different from the anti-penetration display device 100 in that the slow axis of the quarter wave plate 103 is parallel to the X direction (having an azimuth angle of 0 degrees), and the first transmission direction T1 is configured to have an azimuth angle of 135 degrees. Therefore, the quarter wave plate 103 and the first transmission direction T1 are sandwiched by 135 degrees. Accordingly, when ambient light passes through the viewing angle control module 102 of the anti-penetration display device 200, the linearly polarized light passing through the first polarizing layer P1 downward will be transformed into left-handed light/right-handed light after penetrating the quarter-wave plate 103. This left-handed light/right-handed light will be reflected by the metal structure in the self-luminous display panel 101 and transformed into right-handed light/left-handed light. After penetrating the quarter-wave plate 103 upward, it will be transformed into linearly polarized light perpendicular to the first penetration direction T1, and thus will be shielded by the first polarizing layer P1, thereby avoiding the reflection of ambient light.

Since the first penetration direction T1 has an azimuth angle of 135 degrees, the anti-peeping efficiency of the left viewing angle (i.e., 180-degree azimuth angle) can be greatly improved. The anti-peeping viewing angle of the anti-peeping display device 200 is not limited to the above-mentioned left and right anti-peeping. Specifically, since the emitted light of the self-luminous display panel 101 itself has no obvious polarization state, the anti-peeping viewing angle is not limited to the above-mentioned left and right viewing angles, but the direction of the first penetration direction T1 can be changed according to needs, so that it has any azimuth angle, and the anti-peeping viewing angle can be freely changed.

In the embodiment shown in FIG. 2 , the second transmission direction T2 is perpendicular to the second alignment direction D2 of the first liquid crystal layer LC1 and parallel to the third alignment direction D3 of the second liquid crystal layer LC2. The second transmission direction T2 is perpendicular to the first transmission direction T1 and the third transmission direction T3. The first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in O-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in E-mode.

Referring to FIG. 4, a schematic diagram of a viewing angle control module according to an embodiment of the present invention is shown. The viewing angle control module 402 includes a first polarizing layer P1, a first liquid crystal layer LC1, a second polarizing layer P2, a second liquid crystal layer LC2, and a third polarizing layer P3 stacked in sequence, wherein the liquid crystal molecules in the first liquid crystal layer LC1 and the second liquid crystal layer LC2 are twisted nematic liquid crystals (TN liquid crystals), the third alignment direction D3 of the second liquid crystal layer LC2 is parallel to the second transmission direction T2, the fourth alignment direction D4 of the second liquid crystal layer LC2 is parallel to the third transmission direction T3, and the second alignment direction D2 of the first liquid crystal layer LC1 is not parallel to the second transmission direction T2.

The viewing angle control module 402 of FIG. 4 is the same as the viewing angle control module 102 in FIG. 1 and FIG. 2 in that the angle between the first alignment direction D1 of the first liquid crystal layer LC1 and the second alignment direction D2 of the first liquid crystal layer LC1 is 90 degrees, and the first transmission direction T1 is perpendicular to the second transmission direction T2. The viewing angle control module 402 of FIG. 4 is different from the viewing angle control module 102 in FIG. 1 and FIG. 2 in that the angle between the third alignment direction D3 of the second liquid crystal layer LC2 and the fourth alignment direction D4 of the second liquid crystal layer LC2 has an angle θ, and the angle θ is greater than or equal to 45 degrees and less than 90 degrees. In some preferred embodiments, the angle θ falls within the range of 45 degrees to 65 degrees.

Refer to Table 2:

In the comparison example of Table 2, the anti-peeping performance of the structure having a single liquid crystal layer and two polarizing layers sandwiching the single liquid crystal layer was tested. In the third to sixth embodiments of the present invention, the anti-peeping performance of the structure of the viewing angle control module 402 as shown in FIG. 4 was tested, wherein the angle θ was 90 degrees, 65 degrees, 60 degrees, and 45 degrees, respectively. According to Table 2, when the angle θ is 65 degrees, the overall anti-peeping ability is the best. When the angle θ is 60 degrees, the color deviation of the anti-peeping mode relative to the sharing mode is the smallest. When the angle θ is 60 degrees, the large-angle anti-peeping performance is the best.

Referring to FIG. 5 and FIG. 6, part (A) of FIG. 5 shows a schematic diagram of an anti-peeping display device 300 according to an embodiment of the present invention, part (B) of FIG. 5 shows a schematic diagram of an anti-peeping display device 400 according to an embodiment of the present invention, part (A) of FIG. 6 shows a schematic diagram of an anti-peeping display device 500 according to an embodiment of the present invention, and part (B) of FIG. 6 shows a schematic diagram of an anti-peeping display device 600 according to an embodiment of the present invention.

The anti-penetration display devices 300 and 400 include a display panel 201, a viewing angle control module 102, and a fourth polarizing layer P4, wherein the display panel 201 is a liquid crystal display panel and is disposed on the first side S1 of the viewing angle control module 102, that is, the display panel 201 is disposed below the viewing angle control module 102.

For the anti-penetration display devices 300 and 400, the second penetration direction T2 is perpendicular to the first penetration direction T1 and the third penetration direction T3, the first alignment direction D1 of the first liquid crystal layer LC1 is perpendicular to the third alignment direction D3 of the second liquid crystal layer LC2, the second alignment direction D2 of the first liquid crystal layer LC1 is perpendicular to the fourth alignment direction D4 of the second liquid crystal layer LC2, and the third alignment direction D3 of the second liquid crystal layer LC2 is perpendicular to the fourth alignment direction D4 of the second liquid crystal layer LC2.

In the anti-penetration display device 300, the first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in O-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in O-mode.

In the anti-penetration display device 400, the first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in E-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in E-mode.

The anti-penetration display devices 500 and 600 include a display panel 201, a viewing angle control module 102, and a fourth polarizing layer P4, wherein the display panel 201 is a liquid crystal display panel and is disposed on the second side S2 of the viewing angle control module 102, that is, the display panel 201 is disposed above the viewing angle control module 102.

For the anti-penetration display devices 500 and 600, the second penetration direction T2 is perpendicular to the first penetration direction T1 and the third penetration direction T3, the first alignment direction D1 of the first liquid crystal layer LC1 is perpendicular to the third alignment direction D3 of the second liquid crystal layer LC2, the second alignment direction D2 of the first liquid crystal layer LC1 is perpendicular to the fourth alignment direction D4 of the second liquid crystal layer LC2, and the third alignment direction D3 of the second liquid crystal layer LC2 is perpendicular to the fourth alignment direction D4 of the second liquid crystal layer LC2.

In the anti-penetration display device 500, the first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in E-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in E-mode.

In the anti-penetration display device 600, the first polarizing layer P1 and the second polarizing layer P2 are attached to the first liquid crystal layer LC1 in O-mode, and the second polarizing layer P2 and the third polarizing layer P3 are attached to the second liquid crystal layer LC2 in O-mode.

Refer to Table 3, which illustrates the ratio of the brightness at the oblique viewing angle to the brightness at the normal viewing angle when the above-mentioned anti-peeping display devices 300, 400, 500 and 600 are used for right-side anti-peeping (i.e., 180-degree azimuth anti-peeping).

As shown in Table 3, the anti-peeping display device 400 has better optical performance than the anti-peeping display device 300, and its relative brightness is smaller at a side viewing angle of 45 degrees. The anti-peeping display device 600 has better anti-peeping performance than the anti-peeping display device 500, and its relative brightness is smaller at a side viewing angle of 45 degrees.

In summary, the anti-peeping display device provided by the embodiment of the present invention utilizes a dual TN liquid crystal structure to provide good anti-peeping capability. And the phase delay of the dual TN liquid crystal layer falls within the range of 700nm to 1200nm, so that the brightness and chromaticity at the normal viewing angle will not differ significantly between the anti-peeping mode and the sharing mode.

100, 200, 300, 400, 500, 600: Anti-sight display device

101, 201: Display panel

102, 402: View control module

103: Quarter wave plate

D1: First alignment direction

D2: Second alignment direction

D3: The third orientation direction

D4: Fourth orientation direction

LC1: First liquid crystal layer

LC2: Second liquid crystal layer

P1: First polarizing layer

P2: Second polarizing layer

P3: The third polarizing layer

P4: Fourth polarizing layer

S1: First side

S2: Second side

T1: First penetration direction

T2: Second penetration direction

T3: The third penetration direction

X, Y, Z: direction

FIG1 is a schematic diagram of an anti-snooping display device according to an embodiment of the present invention.

FIG2 is a schematic diagram of an anti-obstruction display device according to an embodiment of the present invention.

Figure 3 shows the relationship between the phase delay of the liquid crystal layer and the light transmittance.

FIG4 is a schematic diagram of a viewing angle control module according to an embodiment of the present invention.

FIG5 is a schematic diagram of an anti-obstruction display device according to an embodiment of the present invention.

FIG6 is a schematic diagram of an anti-obstruction display device according to an embodiment of the present invention.

100: Anti-penetration display device 101: Display panel 102: Viewing angle control module 103: Quarter wave plate D1: First alignment direction D2: Second alignment direction D3: Third alignment direction D4: Fourth alignment direction LC1: First liquid crystal layer LC2: Second liquid crystal layer P1: First polarizing layer P2: Second polarizing layer P3: Third polarizing layer S1: First side S2: Second side T1: First penetration direction T2: Second penetration direction T3: Third penetration direction X, Y, Z: Directions

Claims (18)

A peep-proof display device comprises: a display panel; and a viewing angle control module, comprising a first polarizing layer, a first liquid crystal layer, a second polarizing layer, a second liquid crystal layer and a third polarizing layer stacked in sequence, wherein the phase delay of the first liquid crystal layer and the second liquid crystal layer falls within a range of 700nm to 1200nm, wherein the viewing angle control module has a first side close to the first polarizing layer and a second side close to the third polarizing layer, and the display panel is arranged on the viewing angle control module. The first side of the viewing angle control module or the second side of the viewing angle control module is configured, wherein the first polarizing layer has a first transmission direction, the first liquid crystal layer has a first alignment direction and a second alignment direction, the second polarizing layer has a second transmission direction, the second liquid crystal layer has a third alignment direction and a fourth alignment direction, the third polarizing layer has a third transmission direction, and the second transmission direction is not parallel to the first transmission direction and the third transmission direction. The anti-penetration display device as described in claim 1, wherein the phase delay of the first liquid crystal layer and the second liquid crystal layer falls within the range of 872nm±100nm. The anti-penetration display device as described in claim 1, wherein the phase delay of the first liquid crystal layer and the second liquid crystal layer falls within the range of 1066nm±100nm. The anti-penetration display device as described in claim 1, wherein the angle between the third orientation direction of the second liquid crystal layer and the fourth orientation direction of the second liquid crystal layer is in the range of 45 degrees to 90 degrees. An anti-penetration display device as described in claim 4, wherein the angle of the angle is in the range of 45 degrees to 65 degrees. The anti-penetration display device as described in claim 4, wherein the third orientation direction of the second liquid crystal layer is parallel to the second transmission direction, and the fourth orientation direction of the second liquid crystal layer is parallel to the third transmission direction. The anti-penetration display device as described in claim 4, wherein the angle between the first alignment direction of the first liquid crystal layer and the second alignment direction of the first liquid crystal layer is 90 degrees. The anti-penetration display device as described in claim 4, wherein the second alignment direction of the first liquid crystal layer is not parallel to the second penetration direction. The anti-penetration display device as described in claim 4, wherein the first penetration direction is perpendicular to the second penetration direction. The anti-penetration display device as described in claim 1, wherein the second penetration direction is perpendicular to the first penetration direction and perpendicular to the third penetration direction. The anti-penetration display device as described in claim 1 further includes a quarter-wave plate, wherein the display panel is a self-luminous display panel, the display panel is arranged on the first side, and the quarter-wave plate is arranged between the self-luminous display panel and the viewing angle control module. The anti-penetration display device as described in claim 11, wherein the slow axis of the quarter-wave plate is 45 degrees away from the first penetration direction. An anti-penetration display device as described in claim 12, wherein the slow axis of the quarter-wave plate has an azimuth angle of 0 degrees or 90 degrees. The anti-penetration display device as described in claim 11, wherein the first alignment direction of the first liquid crystal layer is parallel to the third alignment direction of the second liquid crystal layer, and the second alignment direction of the first liquid crystal layer is parallel to the fourth alignment direction of the second liquid crystal layer. The anti-penetration display device as described in claim 14, wherein the second penetration direction is parallel to the second alignment direction of the first liquid crystal layer and perpendicular to the third alignment direction of the second liquid crystal layer. The anti-penetration display device as described in claim 15, wherein the second penetration direction is perpendicular to the first penetration direction and the third penetration direction. The anti-penetration display device as described in claim 14, wherein the second penetration direction is perpendicular to the second alignment direction of the first liquid crystal layer and parallel to the third alignment direction of the second liquid crystal layer. The anti-penetration display device as described in claim 17, wherein the second penetration direction is perpendicular to the first penetration direction and the third penetration direction.

Images