KR102002820B1 - Beam deflection panel and display using the same - Google Patents

Abstract

The present invention provides a display device comprising: a display panel for displaying an image; And an optical deflection panel located on a display surface of the display panel and adjusting a tilt angle distribution of the liquid crystal to change a refractive index gradient.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical deflection panel,

The present invention relates to an optical deflection panel, and a display device using the same.

As the information society develops, the demand for the display field is increasing in various forms. In particular, research has been conducted on a display device capable of displaying a 3D image by deflecting light emitted from a display panel using an optical deflection panel that changes the traveling direction of light.

A liquid crystal based optical deflection panel in which electrodes are formed on two substrates and liquid crystal is arranged between two substrates is used as the optical deflection panel. In the liquid crystal based optical deflection panel, when the voltage is not applied, the optical deflection function is turned off, Thereby functioning as an isotropic plate. In such a case, the image emitted from the display panel passes through the optical deflection panel and is transmitted to the viewer.

On the other hand, according to the applied voltage, the liquid crystal director is arranged perpendicular to the electric field direction when the dielectric anisotropy is positive and to the electric field direction when the dielectric anisotropy is negative, so that the distribution of the liquid crystal director depends on the voltage distribution applied to the electrode And as a result, an index gradient due to the refractive index anisotropy of the liquid crystal is caused.

When such a refractive index gradient is used, the optical deflection panel is operated to have an optical deflection function like a lenticular lens, so that a 3D image of a non-eyeglass type can be realized.

As described above, when the liquid crystal based optical deflection panel is used, the optical deflection function can be switched on / off through the liquid crystal array conversion, so that a 2D image or a 3D image can be displayed.

However, conventionally, a refractive index gradient of the liquid crystal is realized so that the optical deflection panel has only a lens function. That is, a refractive index gradient of the liquid crystal is formed so that the incident light can be condensed at a specific position by optically implementing the lens structure.

Thus, optically, the optical deflection panel at deflection driving acts as a device for converting the plane wave incident light into the curved wave output light.

As described above, the conventional optical deflecting panel is deformed into a curved surface wave, and there is a limitation in its use as a device for advancing in a different direction without deforming the wavefront of the incident light.

Therefore, the conventional optical deflection panel has a problem that it can not be used for purposes other than the use for 3D display.

It is an object of the present invention to provide a method that can be used for various purposes by allowing the optical deflection panel to have a function of not changing the wavefront of the incident light.

According to an aspect of the present invention, there is provided a display device comprising: a display panel for displaying an image; And an optical deflection panel located on a display surface of the display panel and adjusting a tilt angle distribution of the liquid crystal to change a refractive index gradient.

Here, the optical deflection panel includes first and second substrates facing each other; A plurality of first and second electrodes respectively formed on inner surfaces of the first and second substrates and corresponding to each other; And a liquid crystal layer between the first and second electrodes, wherein a voltage is applied to the first and second electrodes to adjust a tilt angle distribution of the liquid crystal.

If the tilt angle of the liquid crystal is distributed by the nonlinear function according to the position, the plane wave incident light can be outputted in a state in which the traveling direction is changed while minimizing the deformation of the wavefront shape.

When the tilt angle of the liquid crystal is distributed by a linear function according to the position, the plane wave incident light is transformed into a curved surface wave and the traveling direction can be changed and output.

The nonlinear function is a function proportional to the square of (n / 2) according to the position, and n may be a natural number excluding 2.

In another aspect, the present invention provides an optical deflection panel for a display device, the optical deflection panel being positioned on a display surface of a display panel and adjusting a tilt angle distribution of a liquid crystal to change a refractive index gradient.

Here, first and second substrates facing each other; A plurality of first and second electrodes respectively formed on inner surfaces of the first and second substrates and corresponding to each other; And a liquid crystal layer between the first and second electrodes, wherein a voltage is applied to the first and second electrodes to adjust a tilt angle distribution of the liquid crystal.

If the tilt angle of the liquid crystal is distributed by the nonlinear function according to the position, the plane wave incident light can be outputted in a state in which the traveling direction is changed while minimizing the deformation of the wavefront shape.

When the tilt angle of the liquid crystal is distributed by a linear function according to the position, the plane wave incident light is transformed into a curved surface wave and the traveling direction can be changed and output.

The nonlinear function is a function proportional to the square of (n / 2) according to the position, and n may be a natural number excluding 2.

In the present invention, in the deflection driving of the liquid crystal based optical deflection panel, the tilt angle of the liquid crystal is distributed so as to be proportional to the nonlinear function, so that the plane wavefront of the incident light can be maximally maintained and emitted in the liquid crystal layer. Then, the tilt angle of the liquid crystal can be distributed so as to be proportional to the linear function, and in such a case, the plane wavefront can be transformed into a spherical wavefront and emitted.

When such characteristics are utilized, various types of optical deflection functions can be realized as compared with the conventional one. In addition, various image display functions can be realized through utilization of various optical deflection functions.

1 is a cross-sectional view schematically showing an optical deflection panel and a display device including the same according to an embodiment of the present invention.
2 is a perspective view schematically showing an optical deflection panel according to an embodiment of the present invention.
3 is a diagram illustrating a case where no voltage is applied to an optical deflection panel according to an embodiment of the present invention;
4 is a schematic view showing a liquid crystal director distribution and a light propagation direction according to an embodiment of the present invention.
FIG. 5 illustrates a tilt angle and a refractive index when a tilt angle according to a position follows a linear function according to an embodiment of the present invention; FIG.
FIG. 6 illustrates refractive index and phase when the tilt angle according to the position follows a linear function according to an embodiment of the present invention; FIG.
7 illustrates refractive indices and wavefronts when a tilt angle along a location follows a linear function according to an embodiment of the present invention;
FIGS. 8 and 9 are diagrams illustrating a simulation result of a change in wavefront in a case where a tilt angle according to a position follows a linear function according to an embodiment of the present invention; FIG.
10 is a view showing a tilt angle distribution in a case where a tilt angle of a liquid crystal according to an embodiment is proportional to a linear function and a nonlinear function, respectively, according to an embodiment of the present invention.
11 is a view showing a wavefront shape according to the tilt angle distribution of FIG. 10;
Figure 12 illustrates the expected light output when the tilt angle follows a linear function according to an embodiment of the present invention.
13 is a diagram illustrating the expected light output when the tilt angle follows a non-linear function according to an embodiment of the present invention;
FIG. 14 is a diagram illustrating a simulation result of a change of a wavefront in a case where a tilt angle according to a position follows a nonlinear function according to an embodiment of the present invention; FIG.
15 to 22 are views schematically illustrating examples of performing various image display functions using an optical deflection panel according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an optical deflection panel and a display device including the same according to an embodiment of the present invention. FIG. 2 is a perspective view schematically showing an optical deflection panel according to an embodiment of the present invention.

1 and 2, a display device 100 according to an embodiment of the present invention includes a display panel 200 and an optical deflection panel 300.

The display panel 200 is configured to generate an image, and various types of flat panel display panels can be used. For example, a liquid crystal display panel, a field emission display panel, a plasma display panel, an inorganic electroluminescent panel, and an organic light emitting diode panel, An electroluminescent display panel, an electrophoresis display panel, and the like, may be used.

For example, when the liquid crystal display panel is used as the display panel 200, the display panel 200 includes two opposing substrates, for example, the lower array substrate 210 and the upper opposing substrate 220, And a liquid crystal layer 250 positioned between the two substrates 210 and 220. On the other hand, when the liquid crystal display panel is used as the display panel 200, a backlight unit is formed on the back side of the display panel 200, and light can be supplied to the display panel 200.

The optical deflection panel 300 is disposed on the display surface of the display panel 200 and functions to deflect the image generated in the display panel 200 in various forms according to the display method.

A liquid crystal based optical deflection panel using liquid crystal is used as the optical deflection panel 300, and the deflection function is turned on / off depending on whether a voltage is applied or not.

For example, when no voltage is applied to the optical deflection panel 300, the liquid crystal is arranged in an initial state to act as an optically isotropic plate. On the other hand, when voltage is applied to the optical deflection panel 300, the arrangement of the liquid crystal changes according to the applied voltage. In particular, the director distribution of the liquid crystal is adjusted so as to have a refractive index gradient according to a desired display system. As described above, by changing the refractive index gradient, a desired display method can be implemented in the deflection mode driving.

The optical deflecting panel 300 having such a function is composed of two substrates facing each other, that is, first and second substrates 310 and 320, first and second substrates 310 and 320 formed on the inner surfaces of the first and second substrates 310 and 320, A liquid crystal layer 350 positioned between the first and second substrates 310 and 320,

It is preferable that the first electrodes 311 formed on the first substrate 310 include a plurality of first electrodes 311. The plurality of first electrodes 311 may be spaced apart from each other by a predetermined distance and extend in one direction and extend parallel to each other along the y direction, for example. The first electrode 311 may be made of a transparent conductive material such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), or indium-tin-zinc-oxide (ITZO).

The second electrodes 321 formed on the second substrate 320 are preferably formed to correspond to the first electrodes 311. The plurality of second electrodes 321 may be spaced apart from each other by a predetermined distance and extend in parallel to each other along the y direction. The second electrode 321 may be made of a transparent conductive material such as indium-tin-oxide (ITO), indium-zinc-oxide (IZO), or indium-tin-zinc-oxide (ITZO).

Here, in the deflection mode driving, one of the first and second electrodes 311 and 321 can function as a common electrode to which a constant voltage is applied. In this regard, for example, a common voltage may be applied to the plurality of second electrodes 321, and a driving voltage may be applied to the plurality of first electrodes 311 to control the director of the liquid crystal.

In the above description, the first and second electrodes 311 and 321 are composed of a plurality of electrodes. However, unlike the first and second electrodes 311 and 321, May be integrally formed over the entire surface of the corresponding substrate. In the embodiment of the present invention, for convenience of explanation, a case where a plurality of first and second electrodes 311 and 321 are arranged to face each other in correspondence with each other will be described as an example.

The liquid crystal constituted in the liquid crystal layer 350 can be obtained, for example, in such a manner that the liquid crystal has an initial alignment state in which the director of the liquid crystal is parallel to the substrate surface, and the ideal refractive index, which is the refractive index in the major axis direction, is larger than the normal refractive index . ≪ / RTI >

At this time, although not shown, an orientation film may be formed on the first and second electrodes 311 and 321, respectively, for initial alignment of the liquid crystal.

3, when no voltage is applied to the first and second electrodes 311 and 321 over the entire optical deflection panel 300, the first and second electrodes 311 and 321 are turned on, No electric field is generated. Thus, the liquid crystal 351 is in an initial alignment state, for example, the director is arranged so as to be parallel to the substrate surface, and the tilt angle, that is, the pretilt angle formed by the director of the liquid crystal 351, The angle is 0 degrees.

When no electric field is generated in the liquid crystal layer 350 due to no voltage applied to the first and second electrodes 311 and 321, the optical deflection panel 300 functions as an optically isotropic plate. Thus, the image generated in the display panel 200 can be transmitted to the viewer through the optical deflection panel 300 without substantial change in direction and wavefront.

When a voltage is applied to the first and second electrodes 311 and 321, an electric field is generated between the first and second electrodes 311 and 321. In the case of a liquid crystal having a positive dielectric anisotropy, The direction of the arrow 351 is rotated. On the other hand, in the case of a liquid crystal having a negative negative refractive index anisotropy, the director of the liquid crystal 351 rotates in a direction perpendicular to the electric field direction. Here, the rotation angle or tilt angle of the director is determined according to the magnitude of the generated electric field. For example, as the magnitude of the electric field increases, the tilt angle increases.

In the embodiment of the present invention, the tilt angle distribution of the liquid crystal 351 is adjusted according to the position to change the gradient of the refractive index, thereby realizing various types of deflection functions.

Particularly, in the embodiment of the present invention, it is also proposed that the tilt angle according to the position is configured according to a non-linear function so that the shape of the wave front of the incident light is not deformed.

Hereinafter, the adjustment of the tilt angle distribution of the liquid crystal according to the position during deflection driving will be described in more detail with reference to the drawings.

FIG. 4 is a view schematically showing a liquid crystal director distribution and a light traveling direction according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a case where a tilt angle according to a position follows a linear function according to an embodiment of the present invention FIG. 6 is a view showing the refractive index and the phase when the tilt angle according to the position follows a linear function according to the embodiment of the present invention, and FIG. 7 is a view showing the refractive index and the phase in the embodiment of the present invention In which a tilt angle according to a position follows a linear function. In Fig. 4, the dotted line indicates the wavefront of the light in the liquid crystal layer.

Referring to FIG. 4, the tilt angle of the liquid crystal 351 along the + x direction, for example, as an arrangement direction perpendicular to the extending direction of the first and second electrodes 311 and 321 with respect to the set region, The optical deflection panel 300 is driven to increase. That is, by applying a voltage so that the voltage difference between the first and second electrodes 311 and 321 increases along the + x direction, the tilt angle of the liquid crystal 351 increases.

Here, the illustrated region is a unit region in which a refractive index gradient is generated during deflection driving, and the size and / or position of the region can be adjusted according to the image display form or the like. This can be achieved by adjusting the voltages applied to the first and second electrodes 311 and 321. [

At this time, when the tilt angle according to the position is driven so as to be linearly proportional, the refractive index gradient depending on the position shows a gentle tendency as shown in FIG. In such a case, as shown in Figs. 6 and 7, a phase and a wavefront change depending on the position occur. Referring to FIG. 7, incident light having a planar wavefront at the time of incidence (0 nanosec) of the liquid crystal layer 350 of the optical deflection panel 300, after passing through the liquid crystal layer (0.05 nanosec), has a left- Is delayed.

As described above, when the tilt angle is linearly proportional to the position, it can be confirmed that the wavefront is deformed into a curved shape along the light traveling direction.

In this regard, FIGS. 8 and 9 can be referred to. FIGS. 8 and 9 illustrate a result of simulation of a wavefront change in cases where a tilt angle according to a position follows a linear function according to an embodiment of the present invention Respectively.

8 shows a case in which the tilt angle of the liquid crystal varies linearly from 0 to 90 degrees along the + x axis. In FIGS. 8a to 8d, the dimensions of the refractive index gradient unit areas are 5, 10, Mu m, and 20 mu m, respectively. 9 shows a case where the tilt angle of the liquid crystal along the + x axis changes linearly in the range of 90 degrees -> 0 degrees -> 90 degrees. The simulation result in the case where the length of the refractive index gradient unit area is 8 μm is shown in Respectively. 8 and 9, a liquid crystal having an extraordinary refractive index of 1.8 and a normal refractive index of 1.5 and a substrate having a refractive index of 1.5 are used.

As a result, it can be seen that the incident light of the plane wave passes through the liquid crystal layer 350 and is transformed into a curved surface wave and emitted. It can be confirmed that the light traveling direction changes due to the difference in refractive index between the second substrate 320 and the air layer when the light is emitted from the optical deflection panel 300 to the outside air layer. Here, the light exit angle at the time of simulation (that is, the exit angle based on the substrate normal) has a lower value than the light exit angle according to Snell's law.

Further, it can be seen that as the length of the refractive index gradient unit area is smaller, the change in the light propagation direction, i.e., the degree of deflection, increases, and the curvature radius of the curved surface decreases. As described above, it is possible to control the deflection characteristics of the curved surface wave to be emitted through the adjustment of the refractive index gradient unit area.

Of course, in the above-mentioned simulation, the tilt angle changes from 0 degree to 90 degrees, for example. However, by controlling the applied voltage, it is possible to control the tilt angle change in various other forms, .

As described above, when the optical deflection panel 300 is driven such that the tilt angle of the liquid crystal director is linearly proportional to the position, the plane wave incident light is transformed into a curved surface wave and emitted.

Therefore, the above-described driving, that is, the wavefront shape deformation driving can be applied to a case where incident light is collected at a specific point, for example, 3D image display.

On the other hand, in the embodiment of the present invention, the optical deflection panel 300 can be driven so as to change the direction of the wavefront without deforming the wavefront shape. In this regard, the description will be made with reference to Figs.

10 is a view showing a tilt angle distribution in a case where a tilt angle of a liquid crystal according to an embodiment of the present invention is proportional to a linear function and a nonlinear function, and FIG. 11 is a diagram showing a tilt angle distribution Fig.

FIG. 12 is a graph showing the expected light output when the tilt angle follows a linear function according to an embodiment of the present invention. FIG. 13 is a graph showing the predicted light output when the tilt angle follows a nonlinear function according to an embodiment of the present invention. Fig.

FIG. 14 shows a simulation result of a change of a wavefront in a case where a tilt angle according to a position follows a nonlinear function according to an embodiment of the present invention.

14 corresponds to the above-described FIG. 8, in which the tilt angle of the liquid crystal varies along the + x axis in proportion to the nonlinear function from 0 to 90, where 14a to 14d denote the lengths of the refractive index gradient unit regions 10 mu m, 15 mu m, and 20 mu m in the dimensions of 5 mu m, 10 mu m, 15 mu m, and 20 mu m, respectively. In Fig. 14, a liquid crystal having an extraordinary refractive index of 1.8 and a normal refractive index of 1.5 and a substrate having a refractive index of 1.5 are used.

10 and 11, it can be seen that, when the tilt angle of the liquid crystal is distributed along a nonlinear function, the wavefront has a substantially planar shape. Here, the nonlinear function is a function to make the wavefront of light passing through the liquid crystal layer 350 substantially planar, and such a nonlinear function is determined according to the optical characteristics of the liquid crystal.

As such a nonlinear function, for example, a function proportional to the square of (n / 2) (n is a natural number excluding 2) may be used depending on the position. As an example,? = 90 * (px / d) ^{(n / 2)} + a, 0? F (x)? Here, d is the length in the x direction of the refractive index gradient unit area, px is the position value of the refractive index gradient unit area, n is a natural number excluding 2,? Is the tilt angle of the liquid crystal 351 at the px position, a corresponds to the offset value (i.e., the tilt angle of the liquid crystal at px = 0).

As such, when the tilt angle distribution is made to follow the nonlinear function, the wave front in the liquid crystal layer 350 of the optical deflection panel 300 can have a planar shape. Therefore, as shown in Figs. 13 and 14, the plane wave incident light can be emitted while maintaining the characteristics as a plane wave.

On the other hand, when the tilt angle distribution follows a linear function, as shown in Fig. 12, the plane wave incident light is transformed into a curved surface wave and emitted.

Referring to FIG. 14, it can be seen that the smaller the length of the refractive index gradient unit region is, the larger the change in the light traveling direction, that is, the degree of deflection becomes larger. Thus, by controlling the refractive index gradient unit area, it is possible to control the deflection characteristic of the plane wave to be emitted.

As described above, the drive that does not deform the wavefront shape of the incident light, that is, the wavefront shape undistorted drive can be applied to a case of emitting incident light in a specific direction, such as a dual view image display.

As described above, according to the embodiment of the present invention, in the deflection driving of the liquid crystal-based optical deflection panel, by distributing the tilt angle of the liquid crystal so as to be proportional to the nonlinear function, the plane wavefront of the incident light is maintained in the liquid crystal layer, . Then, the tilt angle of the liquid crystal can be distributed so as to be proportional to the linear function, and in such a case, the plane wavefront can be transformed into a spherical wavefront and emitted.

When such characteristics are utilized, various types of optical deflection functions can be realized as compared with the conventional one. In addition, various image display functions can be realized through utilization of various optical deflection functions.

15 to 22 are views schematically showing examples of performing various image display functions using the optical deflection panel according to the embodiment of the present invention.

FIG. 15 shows a case of displaying an image in a specific direction, which can be implemented by adjusting the tilt angle of the liquid crystal according to the non-linear function as described above.

FIG. 16 shows a dual-view display function, which can be implemented by adjusting the tilt angle of the liquid crystal according to the non-linear function as described above. Here, the refractive-index gradient unit areas having mutually opposite tilt angle distributions are alternately arranged, so that a dual view can be realized. In the dual view implementation, a time division method or a space division method can be applied to the display panel 200, and the distribution of the liquid crystal is adjusted to match the method.

FIG. 17 shows a 3D display function, which can be realized by adjusting the tilt angle of the liquid crystal according to the linear function as described above to generate a lens structure.

FIG. 18 shows a multi-view display function in which the dual view of FIG. 16 is expanded. Also, like the dual view, the time division method or the space division method can be applied.

FIG. 19 shows a security mode display function in which an image is recognized at a certain angle and distance. In such a case, if the display device 100 is provided with an eye-tracking function, the image can be recognized only to the eyes of the user. Such a security mode display function can be realized by driving the optical deflection panel 300 by setting a wide refractive index gradient unit area.

FIG. 20 shows a multi-depth 3D display function for outputting a time-divided 3D image at a different depth. Here, the optical deflection panel 300 can be driven so that an image is output at a corresponding depth in synchronization with the time-divisional images.

FIG. 21 shows a function of outputting a time-divided 2D or 3D image at another specified angle. In this case, when the original image is a 2D image, virtual 3D output is possible, and when the original image is a 3D image, real 3D output is possible. Here, the optical deflection panel 300 can be driven so that images are output at different angles in synchronization with the time-divisional images.

FIG. 22 shows a function of displaying a vision-corrected image so that a viewer can view the image in a case where a screen is viewed through correction means such as eyeglasses for reasons such as myopia. In this case, the original image can be changed to a corrected image suitable for the visual acuity of the viewer through the adjustment of the refractive index gradient of the optical deflection panel 300.

The embodiment of the present invention described above is an example of the present invention, and variations are possible within the spirit of the present invention. Accordingly, the invention includes modifications of the invention within the scope of the appended claims and equivalents thereof.

100: display device 200: display panel
210: array substrate 220: opposing substrate
250: liquid crystal layer 300: optical deflection panel
310: first substrate 311: first electrode
320: second substrate 321: second electrode
350: liquid crystal layer

Claims (12)

A display panel for displaying an image;
An optical deflection panel disposed on the display surface of the display panel and adjusting a tilt angle distribution of the liquid crystal by unit area to change a refractive index gradient,
/ RTI >
The optical deflection panel changes the refractive index gradient for each unit region to change the traveling direction of the plane wave incident light,
The tilt angle of the liquid crystal is distributed so as to gradually increase in one direction parallel to the display surface of the display panel
Display device.
The method according to claim 1,
The optical deflection panel includes:
First and second substrates facing each other;
A plurality of first and second electrodes respectively formed on inner surfaces of the first and second substrates and corresponding to each other;
And a liquid crystal layer between the first and second electrodes,
A voltage is applied to the first and second electrodes to adjust a tilt angle distribution of the liquid crystal
Display device.
The method according to claim 1,
When the tilt angle of the liquid crystal is distributed by a nonlinear function according to the position, the direction of the incident light of the plane wave is changed without changing the wavefront shape,
Display device.
The method according to claim 1,
When the tilt angle of the liquid crystal is distributed by a linear function according to the position, the plane wave incident light is transformed into a curved surface wave,
Display device.
The method of claim 3,
The nonlinear function is a function proportional to the square of (n / 2) according to the position, and n is a natural number excluding 2
Display device.
In an optical deflection panel for a display device,
Changing the gradient of the refractive index by adjusting the tilt angle distribution of the liquid crystal in each unit region, changing the gradient of the refractive index for each unit region to change the traveling direction of the plane wave incident light, Wherein the tilt angle is distributed so that the tilt angle gradually increases in accordance with the position in one direction parallel to the display surface of the display panel.
The method according to claim 6,
First and second substrates facing each other;
A plurality of first and second electrodes respectively formed on inner surfaces of the first and second substrates and corresponding to each other;
And a liquid crystal layer between the first and second electrodes,
A voltage is applied to the first and second electrodes to adjust a tilt angle distribution of the liquid crystal
Optical deflection panel.
The method according to claim 6,
When the tilt angle of the liquid crystal is distributed by a nonlinear function according to the position, the direction of the incident light of the plane wave is changed without changing the wavefront shape,
Optical deflection panel.
The method according to claim 6,
When the tilt angle of the liquid crystal is distributed by a linear function according to the position, the plane wave incident light is transformed into a curved surface wave,
Optical deflection panel.
9. The method of claim 8,
The nonlinear function is a function proportional to the square of (n / 2) according to the position, and n is a natural number excluding 2
Optical deflection panel. 6. The method of claim 5,
The nonlinear function is represented by? = 90 * (px / d) ^{(n / 2)} + a,
d is the length of the refractive index gradient unit area, px is the position value of the refractive index gradient unit area,? is the tilt angle of the liquid crystal at the px position, and a is the tilt angle of the liquid crystal at px =
Display device.
11. The method of claim 10,
The nonlinear function is represented by? = 90 * (px / d) ^{(n / 2)} + a,
d is the length of the refractive index gradient unit area, px is the position value of the refractive index gradient unit area,? is the tilt angle of the liquid crystal at the px position, and a is the tilt angle of the liquid crystal at px =
Optical deflection panel.

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