WO2022196075A1

WO2022196075A1 - Liquid crystal display device

Info

Publication number: WO2022196075A1
Application number: PCT/JP2022/001487
Authority: WO
Inventors: 佳明神山
Original assignee: ソニーグループ株式会社
Priority date: 2021-03-18
Filing date: 2022-01-18
Publication date: 2022-09-22

Abstract

The present disclosure relates to a liquid crystal display device that makes it possible to suppress a decrease in image quality of a display image. The present invention comprises: an effective inner electrode provided in an effective inner region which is a pixel region corresponding to a display image of a liquid crystal panel; an effective outer electrode provided in an effective outer region which is a pixel region not corresponding to the display image, on the periphery of the effective inner region of the liquid crystal panel; and a light-shielding member that is provided so as to cover the effective outer electrode and has an offset with respect to the effective inner electrode in a first direction parallel to the effective outer electrode. The present disclosure can be applied to a liquid crystal display device, an electronic device, a display system, etc., for example.

Description

liquid crystal display

The present disclosure relates to a liquid crystal display device, and more particularly to a liquid crystal display device capable of suppressing reduction in image quality of a displayed image.

Conventionally, in phase modulation elements used for holography, etc., image quality has been improved by optimizing ringing noise caused by sharp wavefront changes at phase distribution edges through iterative calculations (see, for example, Non-Patent Document 1). In addition, a structure has been devised that avoids the influence of disclination by making the pixel voltage at the boundary between the inside of the effective area and outside the effective area the same and shielding the boundary from light (see, for example, Patent Document 1). ).

JP 2012-123303 A

However, in the case of the method described in Non-Patent Document 1, a phase distribution called a blazed pattern is added in order to separate noise light such as unnecessary light, zero-order light, and high-order light from the structure and signal light. Therefore, it was necessary to extract the signal light in such a way that the spatial frequency was greatly restricted. Therefore, there is a possibility that the viewing zone and resolution are reduced by limiting the spatial frequency, and the image quality of the displayed image is reduced.

In the case of the method described in Patent Document 1, it is desirable to provide a light shielding member for shielding the boundary portion outside the panel in order to suppress quality deterioration of the liquid crystal material. It was difficult to precisely place the light shielding edge at the boundary. Therefore, it is difficult to accurately control the wavefront in the non-effective region, and there is a possibility that the image quality of the displayed image is reduced.

The present disclosure has been made in view of such circumstances, and is intended to suppress deterioration in image quality of display images.

A liquid crystal display device according to one aspect of the present technology provides an effective inner electrode provided in an effective inner region that is a pixel region corresponding to a display image of a liquid crystal panel, and the display image around the effective inner region of the liquid crystal panel. an out-effective electrode provided in an out-effective region which is a non-corresponding pixel region, and an out-effective electrode provided to cover the out-effective electrode and having an offset with respect to the in-effective electrode in a first direction parallel to the out-effective electrode and a light shielding member.

In the liquid crystal display device according to one aspect of the present technology, the effective inner electrodes provided in the effective inner region, which is the pixel region corresponding to the display image of the liquid crystal panel, correspond to the display image around the effective inner region of the liquid crystal panel. a non-effective electrode provided in the non-effective region, which is a pixel region that does not cover the effective region, and a light shielding member provided so as to cover the non-effective electrode and having an offset with respect to the in-effective electrode in a first direction parallel to the non-effective electrode. is provided.

It is a figure which shows the structural example of a phase modulation element. FIG. 10 is a diagram illustrating an example of a display image; FIG. It is a figure explaining the example of the separation method of signal light and noise light. FIG. 4 is a diagram showing an example of ringing noise; It is a figure which shows the structural example of a phase modulation element. It is a figure explaining the example of wavefront propagation distance. 1 is a block diagram showing a main configuration example of a liquid crystal display device; FIG. 10 is a flowchart for explaining an example of the flow of display processing; 10 is a flowchart for explaining an example of the flow of phase distribution derivation processing; FIG. 10 is a flowchart continued from FIG. 9 for explaining an example of the flow of phase distribution derivation processing; FIG. 10 is a flowchart for explaining an example of the flow of phase distribution derivation processing; FIG. 12 is a flowchart continued from FIG. 11 for explaining an example of the flow of phase distribution derivation processing; FIG. It is a figure explaining the example of a disclination. It is a figure explaining the example of a disclination. FIG. 10 is a diagram illustrating an example of voltage setting in an out-of-effective area; FIG. 5 is a diagram illustrating an example of outside-of-effective area noise; It is a figure explaining the example of the removal method of noise light. FIG. 10 is a diagram illustrating an example of voltage setting in an out-of-effective area; FIG. 10 is a block diagram showing an example of phase modulation amount setting for the non-effective area; It is a block diagram which shows the main structural examples of a computer.

Hereinafter, a form for carrying out the present disclosure (hereinafter referred to as an embodiment) will be described. The description will be given in the following order.
1. Separation of noise light in phase modulation element2. First embodiment (phase modulation element)
3. Second Embodiment (Display Data Generation)
4. Third Embodiment (Voltage Setting in Effective Area)
5. Fourth Embodiment (Voltage Setting in Effective Area)
6. Supplementary note

<1. Separation of Noise Light in Phase Modulator>
<Documents, etc. that support technical content and technical terms>
The scope disclosed in the present technology is not limited to the contents described in the embodiments, but also the contents described in the following non-patent documents that are publicly known at the time of filing and the following non-patent documents that are referred to The contents of other documents that have been published are also included.

Non-Patent Document 1: (above)
Patent Document 1: (mentioned above)

In other words, the content described in the above non-patent document and the content of other documents referenced in the above non-patent document are also the basis for determining the support requirements.

<Example of noise light separation method in phase modulation element>
FIG. 1 shows a configuration example of a conventional phase modulating element used for holography or the like. A phase modulation element 10 shown in A of FIG. 1 is a reflective phase modulation element using liquid crystal, and A of FIG. 1 shows a cross section thereof. As shown in FIG. 1A, the phase modulation element 10 includes a backplane 12 on which pixel electrodes and driving circuits exist, a counter electrode substrate 11 having a counter electrode, and a counter electrode substrate 11 held between them. and a liquid crystal layer. This panel is placed on a panel holder 13 . Further, a light shielding portion 14 is provided on the upper side in the drawing of the end portion of this panel. The light shielding portion 14 is installed at the end portion of the panel holder 13 . The light shielding portion 14 is formed so as to cover the peripheral portion of the panel on the counter electrode substrate 11 side. That is, the panel is covered with the panel holder 13 and the light shielding portion 14 except for the central portion on the counter electrode substrate 11 side. In other words, the light shielding portion 14 is formed as a part of the panel holder 13, and the portion corresponding to the central portion of the panel on the counter electrode substrate 11 side (the upper side in the drawing) is open, and the light is emitted from this opening. can be incident on the panel. A space (gap) is formed between the light shielding portion 14 and the panel due to the height of the end portion of the panel holder 13 (the length in the vertical direction in the drawing). That is, the light shielding portion 14 and the panel (the counter electrode substrate 11 thereof) are not in contact with each other.

An enlarged view of the dotted line frame P in A of FIG. 1 is shown in B of FIG. A panel (the counter electrode substrate 11 and the backplane 12) is formed with a plurality of pixels (for example, a pixel array), and each pixel has a controllable electrode and a driving circuit.

As shown in FIG. 1B, the panel has an effective inner area 21 and an effective outer area 22 . The effective inner area is a pixel area corresponding to a display image, and is an area in which the voltage of each pixel can be switched sequentially. The effective outer area is a pixel area around the effective inner area that does not correspond to a display image, and is an area to which a certain voltage or pattern is applied.

FIG. 1C is a view of the pixel area of the panel of the phase modulation element 10 viewed from the upper side of FIG. 1A. As shown in FIG. 1C, the pixel area 20 of the panel of the phase modulation element 10 has an effective inner area 21 and an effective outer area 22 . The effective outer area 22 is formed around the effective inner area 21 . That is, the effective inner region 21 is formed in the central portion (inside the effective outer region 22) within the pixel region 20, and the effective outer region 22 is formed in the peripheral portion (outer than the effective inner region 21) within the pixel region 20. formed in

When performing display by phase modulation using this phase modulation element 10, a desired phase distribution is presented in the effective inner region 21 of the phase modulation element 10, and coherent light such as laser light is irradiated thereon. At that time, if the light is irradiated to the effective area 22, diffracted light is generated from structures such as the electrode (also referred to as an external electrode) and the light shielding portion 14 existing there. There is a risk of being affected by the wavefront from the non-effective area 22 . As a result, for example, as shown in FIG. 2, there is a possibility that the image quality of the display image is reduced. FIG. 2 shows a state in which wavy bright and dark noise 31 is generated in the peripheral portion of the display image 30 .

In order to suppress such noise 31, for example, in Non-Patent Document 1, after giving a phase distribution called a blazed pattern, by greatly limiting the spatial frequency, unnecessary light from the structure, 0 A method has been proposed for separating noise light such as next-order light and higher-order light from signal light. However, in the case of this method, it is necessary to insert a filter that limits the spatial frequency band in order to separate the signal light and the noise light. There was a risk that the image quality of the image would be reduced.

Also, when the illumination range is limited so that coherent light is emitted only to the effective inner region, the phase distribution that contributes to image generation is reduced, resulting in a reduction in the quality of the displayed image or a reduction in the size of the displayed image. There was a risk of it happening.

Further, in the method described in Patent Document 1, in which the pixel voltage at the boundary between the effective area and the outside of the effective area of the pixel area is made the same and then the boundary portion is shielded from light, accurate alignment of the light shielding portion is required. Therefore, it is necessary to form a light-shielding portion inside the panel by forming a film. Therefore, there is a risk that the temperature inside the panel will rise due to light absorption in the light shielding portion, and the quality of the liquid crystal material will be reduced. For this reason, it is desirable that the light shielding part is located outside the panel. Control could become difficult. Therefore, the noise 31 described above increases, and there is a possibility that the image quality of the displayed image is reduced.

Also, for example, when performing propagation that separates signal light and noise light, there is a risk that the spatial frequency band will be narrowed by a filter using a 4f optical system when extracting the signal light, resulting in a narrower viewing zone. there were. For example, without a filter, the gray portion was the viewing area (that is, the range in which the reproduced image can be seen) for the phase modulation element shown in FIG. 3A, but with the filter, the phase modulation element There was a possibility that the viewing zone for the 3D would be narrower than that for the case of A in FIG.

Therefore, the signal light and noise light are propagated without being separated, and the image quality deterioration is improved. By doing so, it is possible to extract the signal light without narrowing the band, and it is possible to achieve both high image quality and a wide viewing range.

<2. First Embodiment>
<Phase modulation element>
For example, in the phase modulation element 10 of FIG. 1, when the light is irradiated onto the light shielding portion 14, the sharp change in the light intensity at the edge of the light shielding portion 14 causes the light intensity to wave, for example, as shown in FIG. Hit-like noise (hereinafter also referred to as ringing noise) occurs in the image. At this time, when the light-shielding region is x≦0, the relative intensity distribution can be expressed, for example, by the following equation (1).

... (1)
however,

Therefore, since the change in light intensity is small at a position more than √λZ away from the light shielding edge, the effect of diffracted light caused by light shielding can be reduced by placing the light shielding edge at least √λZ away from the boundary of the effective area. can be avoided. λ indicates the wavelength of irradiation light (for example, laser light) with which the phase modulation element 10 is irradiated. Also, Z indicates the propagation distance of the wavefront (distance from the surface of the phase modulation element 10 (also referred to as the element surface) to the reproduction surface where the image is reproduced). √λZ denotes the square root of λZ, ie, the square root of the product of the wavelength of the illuminating light and the propagation distance of the wavefront.

FIG. 5 is a block diagram showing a main configuration example of a phase modulation element, which is an embodiment of a liquid crystal display device to which the present technology is applied. A phase modulation element 100 shown in FIG. 5A is a reflective phase modulation element using liquid crystal, which is used for holography or the like. FIG. 5A shows a cross section of the phase modulating element 100. FIG. As shown in FIG. 5A, the phase modulation element 100 includes a backplane 112 on which pixel electrodes and driving circuits exist, a counter electrode substrate 111 having a counter electrode, and a counter electrode substrate 111 held between them. and a liquid crystal layer. This panel is placed on a panel holder 113 . Further, a light shielding portion 114 is provided on the upper side in the figure of the end portion of this panel. The light shielding portion 114 is installed at the end portion of the panel holder 113 . The light shielding portion 114 is formed so as to cover the peripheral portion of the panel on the counter electrode substrate 111 side. That is, the panel is covered with the panel holder 113 and the light shielding part 114 except for the central part on the counter electrode substrate 111 side. In other words, the light shielding portion 114 is formed as a part of the panel holder 113, and the portion corresponding to the central portion of the panel on the side of the counter electrode substrate 111 (the upper side in the drawing) is open, and the light is emitted from this opening. can be incident on the panel. In the example shown in A of FIG. 5, a space (gap) is formed between the light shielding portion 114 and the panel due to the height of the end portion of the panel holder 113 (length in the vertical direction in the drawing). there is That is, the light shielding portion 114 and the panel (the counter electrode substrate 111 thereof) are not in contact with each other. However, this is an example, and the light shielding portion 114 and the panel may be in contact with each other.

An enlarged view of the part surrounded by the dotted line frame Q in A of FIG. 5 is shown in B of FIG. A panel (the counter electrode substrate 111 and the backplane 112) is formed with a plurality of pixels (for example, a pixel array), and each pixel has a controllable electrode and a driving circuit.

As shown in FIG. 5B, the panel has an effective inner area 121 and an effective outer area 122 . The effective inner area 121 is a pixel area corresponding to a display image, and is an area in which the voltage of each pixel can be switched sequentially. The effective outer area 122 is a pixel area around the effective inner area 121 that does not correspond to a display image, and is an area to which a certain voltage or pattern is applied. The pixel electrodes in the effective inner region 121 are also called effective inner electrodes, and the pixel electrodes in the effective outer region 122 are also referred to as outer effective electrodes. The positional relationship between the effective inner area 121 and the effective outer area 122 is the same as the effective inner area 21 and the effective outer area 22 described with reference to FIG.

As shown in FIG. 5B, the light shielding portion 114 extends in the effective inner area 121 (the effective inner electrode) in the direction parallel to the panel (that is, the direction parallel to the effective outer electrodes) with a predetermined offset (double arrow 131).

For example, an offset may be provided between the end of the light shielding portion 114 and the end of the inner effective electrode (inner effective region 121) in the first direction.

By providing the offset in this manner, the effective inner region 121 can be separated from the end of the light shielding portion 114 . As shown in FIG. 4, the ringing noise generated in the vicinity of the edge of the light shielding portion 114 becomes smaller as the distance from the edge of the light shielding portion 114 increases. Therefore, as described above, by locating the end of the light shielding portion 114 farther from the effective inner region 121, the distance from the effective outer region 122 at the periphery of the effective inner region 121 as shown in FIG. can suppress the influence of the wavefront of As a result, it is possible to suppress an increase in brightness noise (noise 31 in FIG. 2) occurring in the peripheral portion of the displayed image.

The magnitude of this offset (the length of the double arrow 131) is arbitrary. For example, the magnitude of the offset may be the distance corresponding to the wavelength λ of the irradiation light with which the panel of the phase modulation element 100 is irradiated.

For example, the magnitude of the offset may be a distance equal to or greater than the square root of the product of the wavelength λ of the irradiation light irradiated to the panel of the phase modulation element 100 and the propagation distance Z of the wavefront. Wavefront propagation distance (distance from the surface (also referred to as the element surface) of the phase modulation element 100 to the reproduction surface where an image is reproduced) is shown.

As described above, the change in light intensity is small at a position more than √λZ away from the end of the light shielding portion 114. Therefore, by setting the offset to √λZ or more, the influence of diffracted light caused by light shielding can be avoided. can be done.

<3. Second Embodiment>
<Display data generation>
In addition, since the reflectance and the applied voltage of the electrodes in the exposed non-effective area are known, the light intensity distribution and the phase distribution can be known. Therefore, by adopting this configuration, the wavefront outside the effective area can be introduced into the propagation calculation, and the image quality can be improved in consideration of the influence of noise light from outside the effective area.

For example, display data, which is control information for controlling the driving of each pixel of the panel (liquid crystal panel), may be generated based on the target light intensity distribution of the reproduction surface. Then, at that time, display data may be generated in which the difference between the light intensity distribution generated on the reproduction surface by the panel reflecting the irradiation light and the target light intensity distribution is within a predetermined allowable range. Further, at that time, by performing wavefront propagation calculation using the light intensity distribution and phase distribution of the effective inner region and the effective outer region, display data whose difference is within the allowable range may be generated.

Since the change in light intensity due to the edge of the light shielding portion 114 is remarkable in a region where the wavefront propagation distance is short, the wavefront propagation calculation may be performed using Fresnel diffraction calculation, each spectrum method, or its modification. For example, as shown in FIG. 6, when the wavefront on the phase modulation element surface is u ₁ (x ₁ , y ₁ ) and the wavefront on the propagation destination is u ₂ (x ₂ , y ₂ ), Fresnel diffraction is It can be expressed as in the following formula (2). The angular spectrum method can be expressed as in Equation (3) below.

... (2)

... (3)

Here, fx, fy indicate the coordinates in frequency space. Applying the wavefront information of the effective inner region and the outer effective region of the phase modulating element to the equation (2) or (3), iterative calculation is performed. By doing so, it is possible to remove the influence of the diffracted light from the non-effective area and suppress the deterioration of the image quality at the propagation destination serving as the image reproducing surface.

The Gerchberg-Saxton method (GS method) may be applied to iterative calculations. The GS method is a method of optimizing the phase distribution by sequentially updating the phase information on the wavefront in the phase modulation element and the wavefront on the reproduction plane, which is the propagation destination, with the known light intensity distribution information as a fixed condition. is. Alternatively, a technique of calculating the gradient of the phase and performing optimization while sequentially updating the phase information on the phase modulation element using the gradient descent method or the like may be applied.

<Liquid crystal display device>
FIG. 7 is a block diagram showing a main configuration example of a liquid crystal display device to which the present technology is applied. A liquid crystal display device 300 shown in FIG. 7 is a display device using a liquid crystal applied to holography. As shown in FIG. 7 , the liquid crystal display device 300 has a display data generation section 311 and a display section 312 . The display data generation unit 311 generates display data, which is control information for controlling driving of each pixel of the liquid crystal panel of the phase modulation element. For example, the display data generator 311 generates display data based on a target light intensity distribution, which is a target value of the light intensity distribution on the image reproduction plane, which is input to the liquid crystal display device 300 . The display data generation unit 311 supplies the generated display data to the display unit 312 .

The display unit 312 displays a display image corresponding to the supplied display data on the image reproduction screen.

The display data generation unit 311 has a phase distribution derivation unit 321 . The phase distribution derivation unit 321 derives the phase distribution on the element surface so that the difference between the light intensity distribution on the image reproduction surface and the target light intensity distribution is within the allowable range. The phase distribution derivation unit 321 supplies the derived phase distribution to the display unit 312 (the phase modulation element control unit 331 thereof) as display data.

The display section 312 has a phase modulation element control section 331 , an illumination section 332 and a phase modulation element 333 . The phase modulation element control unit 331 controls each pixel (electrode of) of the phase modulation element 333 based on the display data supplied from the display data generation unit 311 (that is, the phase distribution supplied from the phase distribution derivation unit 321). to control. For example, the phase modulation element control section 331 reproduces the display data supplied from the display data generation section 311 (that is, the phase distribution supplied from the phase distribution derivation section 321) on the liquid crystal panel of the phase modulation element 333. , controls the effective inner electrode and the outer effective electrode of the phase modulation element 333 .

The illumination unit 332 irradiates the phase modulation element 333 controlled by the phase modulation element control unit 331 with reference light (for example, laser light).

The phase modulation element 333 is controlled by the phase modulation element control unit 331, reproduces the phase distribution corresponding to the display data in the pixel area, diffracts the reference light emitted from the illumination unit 332, and displays the display image on the image reproduction surface. display.

In the liquid crystal display device 300 having such a configuration, the present technology can be applied to the phase modulation element 333 . That is, the phase modulating element 100 described above may be applied as the phase modulating element 333 . That is, the phase modulating element 333 may have the configuration described in the first embodiment.

For example, the phase modulation element 333 may have a light shielding portion arranged to have a predetermined offset with respect to the effective inner area (effective inner electrode) in the direction parallel to the liquid crystal panel. Further, for example, an offset may be provided between the end portion of the light shielding portion and the end portion of the effective inner electrode (effective inner region) in that direction. Furthermore, the magnitude of the offset may be a distance corresponding to the wavelength λ of the illumination light (reference light) that is emitted from the illumination section 332 to the liquid crystal panel of the phase modulation element 333 . Further, the magnitude of the offset may be set to a distance equal to or larger than the square root of the product of the wavelength λ of the irradiation light with which the liquid crystal panel of the phase modulation element 333 is irradiated and the propagation distance Z of the wavefront.

By doing so, the phase modulation element 333 can suppress an increase in brightness noise occurring in the peripheral portion of the display image, and can suppress a decrease in the image quality of the display image.

In addition, in the liquid crystal display device 300 having such a configuration, the present technology can be applied to the display data generation unit 311 (phase distribution derivation unit 321). That is, as described above, the display data generation unit 311 determines the difference between the light intensity distribution generated on the image reproduction surface by the reflection of the reference light emitted from the illumination unit 332 by the phase modulation element 333 and the target light intensity distribution. may be generated within a predetermined allowable range. Further, at that time, by performing wavefront propagation calculation using the light intensity distribution and phase distribution of the effective inner region and the effective outer region, display data whose difference is within the allowable range may be generated.

Furthermore, at that time, the display data generation unit 311 may generate display data by performing iterative calculations. For example, the display data generation unit 311 may generate display data by performing iterative calculations by applying the GS method.

For example, the display data generation unit 311 uses the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the element surface of the liquid crystal panel to obtain the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the image reproduction surface. Derive the light intensity distribution and phase distribution of the effective inner area and the effective outer area on the element surface using the propagation calculation for deriving the phase distribution and the light intensity distribution and phase distribution of the effective inner area and the effective outer area on the image reproduction plane. By repeating the back propagation calculation, display data may be generated in which the difference between the light intensity distribution generated on the image raw surface and the target light intensity distribution is within the allowable range.

Further, for example, the display data generation unit 311 calculates the gradient of the phase, sequentially updates the phase information on the phase modulation element using the gradient descent method, etc., and applies an optimization technique to perform iterative calculation. Display data may be generated by performing

For example, the display data generation unit uses the light intensity distribution and phase distribution of the effective inner area and the effective outer area on the element surface of the liquid crystal panel to obtain the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the image reproduction surface. By repeating the propagation calculation for deriving the distribution and the calculation for deriving the gradient of the phase distribution on the element surface so that the difference between the light intensity distribution generated on the image raw surface and the target light intensity distribution becomes small, the difference is allowed. Display data that falls within the range may be generated.

<Flow of display processing>
An example of the flow of display processing executed by the liquid crystal display device 300 will be described with reference to the flowchart of FIG.

When the display process is started, the phase distribution derivation unit 321 of the liquid crystal display device 300 executes the phase distribution derivation process in step S301 to derive the phase distribution (that is, display data) of the element surface.

In step S302, the phase modulation element control section 331 controls the phase modulation element 333 to reproduce the phase distribution derived in step S301. In step S303, the illumination unit 332 irradiates the liquid crystal panel of the phase modulation element 333 on which the phase distribution is formed by the process of step S302 with reference light such as laser light.

When the process of step S303 ends, the display process ends. By executing each process in this manner, a desired display image is displayed on the image reproduction screen. Then, in step S301, by executing the phase distribution derivation process by applying the present technology described above, it is possible to suppress deterioration in the image quality of the display image as described above.

<Phase distribution derivation process flow 1>
For example, the GS method may be applied to the phase distribution derivation process executed in step S301 of FIG. An example of the flow of the phase distribution derivation process in that case will be described with reference to the flowcharts of FIGS. 9 and 10. FIG.

When the phase distribution derivation process is started, in step S321 of FIG. 9, the phase distribution derivation unit 321 sets a known light intensity distribution A1 and _an arbitrary _phase distribution Φ1 in the effective inner area of the phase modulation element surface. do. Also, in step S322, the phase distribution derivation unit 321 sets the known light intensity distribution A1 and the known _phase distribution Φ1 in the non _- effective area of the phase modulation element surface. At this time, the intensity distribution is given as a fixed value because the distribution of the light source that irradiates the phase modulation element is known, and the phase distribution is given arbitrarily because it is an optimization target. Also, the intensity distribution and phase distribution of the non-effective area are given as known and fixed conditions.

In step S323, the phase distribution deriving unit 321 calculates the propagation of the wavefront created by these, and obtains the intensity distribution and phase distribution on the reproduction plane. Since the wavefront can be represented by a complex amplitude, if the light intensity distribution is A ₁ and the phase distribution is Φ ₁ , the wavefront u ₁ is u ₁ (x ₁ , y ₁ ) = A ₁ (x ₁ , y ₁ )e It can be expressed as ^iΦ1(x1,y1) . Ultimately, the aim is to optimize the phase distribution on the phase modulation element surface and obtain a desired intensity distribution on the image reproduction surface after propagation.

In step S324, the phase distribution deriving unit 321 compares the intensity distribution on the reproduction plane with the desired intensity distribution. Then, the phase distribution derivation unit 321 determines whether the difference between the derived light intensity distribution _A2 on the reproduction surface after propagation and the target light intensity distribution B2 _on the reproduction surface is within the allowable range. do.

If it is determined that it is not within the allowable range, the process proceeds to step S325. In this case, the phase distribution derivation unit 321 performs back propagation calculation after replacing the intensity distribution with a desired intensity distribution while keeping the phase distribution after propagation. In step S325, the phase distribution derivation unit 321 replaces the light intensity distribution _A2 on the reproduction surface after propagation with the target light intensity distribution B2 _on the reproduction surface. _In step S326, the phase distribution deriving unit 321 takes over the phase distribution Φ2 on the reproduction plane after propagation. After the process of step S326 is completed, the process proceeds to FIG.

In step S331 of FIG. 10, the phase distribution derivation unit 321 performs back propagation calculation, which is the inverse process of the above-described propagation calculation.

Then, the phase distribution derivation unit 321 replaces the in-effective area and out-of-effective intensity distribution obtained by the back propagation calculation and the out-of-effective phase distribution with known conditions, and inherits the in-effective phase distribution. In step S332, the phase distribution deriving unit 321 replaces the light intensity distribution _B1 in the effective inner region of the phase modulation element surface after back propagation with the light intensity distribution A1 on the _phase modulation element surface. In step S333, the phase distribution derivation unit 321 takes over the _phase distribution Θ1 of the effective inner area of the _phase modulation element surface after back propagation to the phase distribution Φ1 of the phase modulation element surface. In step S334, the phase distribution deriving unit 321 replaces the light intensity distribution _B1 in the non-effective area of the phase modulation element surface after back propagation with the light intensity distribution A1 on the _phase modulation element surface. In step S335, the phase distribution derivation unit 321 replaces the _phase distribution Θ1 of the non-effective region of the _phase modulation element surface after back propagation with the phase distribution Φ1 of the phase modulation element surface. When the process of step S335 ends, the process returns to step S323 of FIG.

In this way, optimization is performed while repeating the propagation calculation and updating the intensity distribution and phase distribution. In other words, optimization is performed by repeatedly executing the processes of steps S323 to S326 in FIG. 9 and steps S331 to S335 in FIG.

Then, in step S324 in _FIG . 9, if it is determined that the difference between the light intensity distribution _A2 on the reproduction surface after propagation and the target light intensity distribution B2 on the reproduction surface is within the allowable range, the process is The process proceeds to step S327.

In step S327, the phase distribution derivation unit 321 outputs the phase distribution Φ1 of the effective inner area of the _phase modulation element surface to the display unit 312 as display data.

When the process of step S327 ends, the phase distribution derivation process ends.

By executing each process in this manner, the phase distribution derivation unit 321 can suppress the influence of the diffracted light from the non-effective area, and reduce the image quality of the displayed image at the propagation destination serving as the image reproduction surface. can be suppressed.

<Phase distribution derivation process flow 2>
For example, in the phase distribution derivation process executed in step S301 of FIG. 8, a method of calculating the gradient of the phase and performing optimization while sequentially updating the phase information on the phase modulation element using the gradient descent method or the like is used. may apply. An example of the flow of the phase distribution derivation process in that case will be described with reference to the flowcharts of FIGS. 11 and 12. FIG.

In this case, steps S351 to S354 of FIG. 11 are executed in the same manner as steps S321 to S324 of FIG. That is, the phase distribution deriving section 321 first sets the intensity distribution and the phase distribution of the effective inner area of the phase modulation element. At this time, the intensity distribution is given as a fixed value because the distribution of the light source that irradiates the phase modulation element is known, and the phase distribution is given arbitrarily because it is an optimization target. Then, the phase distribution deriving unit 321 performs propagation calculation on the wavefront created by these, and obtains the intensity distribution and the phase distribution on the reproduction plane. Then, the phase distribution derivation unit 321 compares the intensity distribution on the reproduction surface with the desired intensity distribution.

If it is determined in step S354 that the difference between the light intensity distribution _A2 on the reproduction surface after propagation and the target light intensity distribution B2 _on the reproduction surface is not within the allowable range, the process proceeds to step S355. In this case, the phase distribution deriving section 321 calculates the gradient of the phase distribution on the phase modulation element surface so that the difference is small. For the gradient calculation at that time, derivation by a method called Wirtinger Holography or an optimizer for machine learning can be used. In step S355, the phase distribution deriving unit 321 calculates the phase distribution on the phase modulation element surface so that the difference between the light intensity distribution _A2 on the reproduction surface after propagation and the target light intensity distribution B2 _on the reproduction surface is small. Derive the gradient of When the process of step S355 ends, the process proceeds to FIG.

After deriving the gradient, the phase distribution deriving unit 321 uses the calculated phase gradient to update the phase distribution of the effective inner region on the phase modulation element surface, and the intensity distribution of the effective inner region, which is other known information, Set the intensity distribution and phase distribution of the non-effective area. In step S361 of FIG. 12, the phase distribution deriving unit 321 _sets the known light intensity distribution A1 in the effective inner area of the phase modulation element surface. In step _S362 , the phase distribution derivation unit 321 updates the phase distribution Φ1 of the effective inner area of the phase modulation element surface using the gradient derived in step S355. In step S363, the phase distribution deriving unit 321 _sets the known light intensity distribution A1 in the non-effective region of the phase modulation element surface. In step S364, the phase distribution derivation unit 321 replaces the phase distribution Φ1 in the effective non-effective area of the phase modulation element surface with a known _phase distribution Φ1. After the process of step S364 is completed, the process returns to step S353 of FIG.

The phase distribution derivation unit 321 creates a wavefront on the phase modulation element surface, and performs optimization while repeating propagation calculation, gradient calculation, and updating of the phase distribution again. That is, the optimization is performed by repeatedly executing the processes of steps S353 to S355 in FIG. 11 and steps S361 to S364 in FIG.

Then, in step S354 of _FIG . 11, if it is determined that the difference between the light intensity distribution _A2 on the reproduction surface after propagation and the target light intensity distribution B2 on the reproduction surface is within the allowable range, the process is The process proceeds to step S356.

In step S356, the phase distribution derivation unit 321 outputs the phase distribution Φ1 of the effective inner area of the _phase modulation element surface to the display unit 312 as display data.

When the process of step S356 ends, the phase distribution derivation process ends.

<4. Third Embodiment>
<Disclination>
Disclination may occur in a phase modulation element using liquid crystal. As shown in FIG. 13, in the liquid crystal panel 400 of the liquid crystal type phase modulation element, the electric field generated by the difference between the voltage applied to the pixel electrode of the back plane and the voltage applied to the counter electrode substrate causes the liquid crystal molecules to move. The amount of phase modulation is controlled by controlling the tilt angle. However, when a voltage difference occurs between adjacent electrodes in the backplane, the electric field generated by the voltage difference becomes noise, and the liquid crystal molecules cannot be controlled at a desired angle. For example, in FIG. 13, the liquid crystal molecules cannot be controlled at a desired angle between the low voltage pixel 411 and the high voltage pixel 412 of the liquid crystal panel 400 . A portion where such control is not possible is called a disclination. At a location where such disclination occurs, there is a possibility that a desired phase modulation amount cannot be obtained as shown in FIG. 14, for example. In this way, when the set voltage values differ significantly between the inside and outside of the effective range, disclination may occur there and appear as noise on the wavefront.

<Voltage setting in the effective area>
Therefore, the voltage setting value for the outer effective region (outer effective electrode) may be set within the voltage range used in the inner effective region (inner effective electrode). For example, as shown in FIG. 15, if a voltage range in which the amount of phase modulation is from π to 3π is used in the effective inner region, the voltage of the outer effective electrode is set within the range indicated by the double arrow in the drawing. set. By doing so, it is possible to prevent a large voltage difference from being generated between the outer effective electrode and the inner effective electrode, and it is possible to reduce noise on the wavefront. Therefore, it is possible to suppress deterioration of the image quality of the display image.

For example, the voltage of the outer effective electrode may be set to the median value of the voltage range used for the inner effective electrode. By doing so, it is generally possible to further reduce the voltage difference between the outer and inner effective electrodes. Therefore, it is possible to further suppress the deterioration of the image quality of the display image.

For example, in the liquid crystal display device 300 of FIG. Control so that it is within the voltage range. By doing so, it is possible to suppress deterioration in the image quality of the display image displayed by the liquid crystal display device 300 .

<5. Fourth Embodiment>
<Separation of signal light and noise light>
By the way, let us consider extracting the signal light from the intensity distribution on the image reproducing surface. As shown in FIG. 16, in the pixel area, the light from the effective outside area 502 not only remains as noise light in the inside effective area 501, but also remains as noise light (outside effective area noise 511) in the outside effective area 502. can remain

If such noise light remains, for example, as shown in FIG. 17A, by providing a zero-order optical filter 522 in front of the phase modulation element 521, the signal light can be extracted without significantly limiting the viewing zone. can be done. The 0th-order light filter includes a method of blocking the 0th-order light on the Fourier plane after condensing with a lens, and a method of reflecting only the 0th-order light by a Bragg grating created by a volume hologram.

Also, as shown in FIG. 17B, for example, by inserting an aperture 523 in front of the phase modulating element 521, the signal light can be extracted without greatly restricting the viewing area.

However, if the position of the aperture 523 is displaced, there is a risk of affecting the viewing zone. Therefore, in order to separate signal light and noise light more accurately, the position of aperture 523 had to be set more accurately.

<Voltage setting in the effective area>
Therefore, the voltage applied to the out-of-effective electrode may be removed by the aperture 523 after a predetermined pattern is given to the voltage. For example, the voltage of the out-effective electrode may be set so that the irradiation light (reference light) applied to the out-effective region is diffracted away from the in-effective region. By doing so, the noise light in the effective outer area is propagated away from the reproduced image in the effective inner area, so that the noise light can be easily removed by the aperture 523 . Therefore, it is possible to suppress deterioration of the image quality of the display image.

In other words, even if the position of the aperture 523 deviates from the correct position, noise light can be removed. That is, the accuracy required for the position of aperture 523 is reduced. That is, it is possible to improve robustness when installing the aperture.

Also, for example, the voltage of the out-of-effective electrode may be set so that the phase of the pixels outside the out-of-effective area is delayed. For example, the voltage of the out-of-effective electrode may be set so that the phase modulation amount increases in pixels outside the in-effective region. By doing so, the noise light in the effective outer area is propagated away from the reproduced image in the effective inner area, so that the noise light can be easily removed by the aperture 523 .

For example, as shown in FIG. 18, the voltage of the non-effective electrode may be set so that the phase modulation amount increases by 0.5π for each pixel row or pixel column in the non-effective region. In other words, the phase modulation amount distribution in the non-effective region may be stepped as shown in FIG. For example, if the number of steps is a and the pixel position from the edge of the effective inner area to the panel periphery is i (0, 1, 2, ..., n), the distribution p of the steps is expressed by the following equation (4 ) can be expressed as

... (4)

For example, in the liquid crystal display device 300 shown in FIG. 7, the phase modulation element control section 331 controls the non-effective region of the phase modulation element 333 ( set the voltage of the active electrode). By doing so, it is possible to suppress deterioration in the image quality of the display image displayed by the liquid crystal display device 300 .

<6. Note>
<Computer>
The series of processes described above can be executed by hardware or by software. When executing a series of processes by software, a program that constitutes the software is installed in the computer. Here, the computer includes, for example, a computer built into dedicated hardware and a general-purpose personal computer capable of executing various functions by installing various programs.

FIG. 20 is a block diagram showing an example of the hardware configuration of a computer that executes the series of processes described above by a program.

In a computer 900 shown in FIG. 20, a CPU (Central Processing Unit) 901, a ROM (Read Only Memory) 902, and a RAM (Random Access Memory) 903 are interconnected via a bus 904.

An input/output interface 910 is also connected to the bus 904 . An input unit 911 , an output unit 912 , a storage unit 913 , a communication unit 914 and a drive 915 are connected to the input/output interface 910 .

The input unit 911 consists of, for example, a keyboard, mouse, microphone, touch panel, input terminal, and the like. The output unit 912 includes, for example, a display, a speaker, an output terminal, and the like. The storage unit 913 is composed of, for example, a hard disk, a RAM disk, a nonvolatile memory, or the like. The communication unit 914 is composed of, for example, a network interface. Drive 915 drives removable media 921 such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory.

In the computer configured as described above, the CPU 901 loads, for example, a program stored in the storage unit 913 into the RAM 903 via the input/output interface 910 and the bus 904, and executes the above-described series of programs. is processed. The RAM 903 also appropriately stores data necessary for the CPU 901 to execute various processes.

A program executed by a computer can be applied by being recorded on removable media 921 such as package media, for example. In that case, the program can be installed in the storage unit 913 via the input/output interface 910 by loading the removable medium 921 into the drive 915 .

This program can also be provided via wired or wireless transmission media such as local area networks, the Internet, and digital satellite broadcasting. In that case, the program can be received by the communication unit 914 and installed in the storage unit 913 .

In addition, this program can be installed in the ROM 902 or the storage unit 913 in advance.

<Application target of this technology>
This technology can be applied to any configuration. For example, the present technology can be applied to various electronic devices related to holography.

In addition, for example, the present technology may be a processor (e.g., video processor) as a system LSI (Large Scale Integration), etc., a module using multiple processors, etc., a unit using multiple modules, etc., or adding other functions to the unit. It can also be implemented as a part of the configuration of the device, such as an added set.

Also, for example, the present technology can also be applied to a network system configured by a plurality of devices. For example, the present technology may be implemented as cloud computing in which a plurality of devices share and jointly process via a network. For example, this technology is implemented in cloud services that provide image (moving image) services to arbitrary terminals such as computers, AV (Audio Visual) equipment, portable information processing terminals, and IoT (Internet of Things) devices. You may make it

In this specification, a system means a set of multiple components (devices, modules (parts), etc.), and it does not matter whether all the components are in the same housing. Therefore, a plurality of devices housed in separate housings and connected via a network, and a single device housing a plurality of modules in one housing, are both systems. .

<Fields and applications where this technology can be applied>
Systems, devices, processing units, etc. to which this technology is applied can be used in any field, such as transportation, medical care, crime prevention, agriculture, livestock industry, mining, beauty, factories, home appliances, weather, and nature monitoring. . Moreover, its use is arbitrary.

<Others>
Embodiments of the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present technology.

For example, a configuration described as one device (or processing unit) may be divided and configured as a plurality of devices (or processing units). Conversely, the configuration described above as a plurality of devices (or processing units) may be collectively configured as one device (or processing unit). Further, it is of course possible to add a configuration other than the above to the configuration of each device (or each processing unit). Furthermore, part of the configuration of one device (or processing unit) may be included in the configuration of another device (or other processing unit) as long as the configuration and operation of the system as a whole are substantially the same. .

Also, for example, the above-described program may be executed on any device. In that case, the device should have the necessary functions (functional blocks, etc.) and be able to obtain the necessary information.

Also, for example, each step of one flowchart may be executed by one device, or may be executed by a plurality of devices. Furthermore, when one step includes a plurality of processes, the plurality of processes may be executed by one device, or may be shared by a plurality of devices. In other words, a plurality of processes included in one step can also be executed as processes of a plurality of steps. Conversely, the processing described as multiple steps can also be collectively executed as one step.

Further, for example, a computer-executed program may be configured such that the processing of the steps described in the program is executed in chronological order according to the order described in this specification, in parallel, or when calls are executed. It may also be executed individually at necessary timings such as when it is interrupted. That is, as long as there is no contradiction, the processing of each step may be executed in an order different from the order described above. Furthermore, the processing of the steps describing this program may be executed in parallel with the processing of other programs, or may be executed in combination with the processing of other programs.

Also, for example, multiple technologies related to this technology can be implemented independently as long as there is no contradiction. Of course, it is also possible to use any number of the present techniques in combination. For example, part or all of the present technology described in any embodiment can be combined with part or all of the present technology described in other embodiments. Also, part or all of any of the techniques described above may be implemented in conjunction with other techniques not described above.

Note that the present technology can also take the following configuration.
(1) an effective inner electrode provided in an effective inner region which is a pixel region corresponding to a display image of a liquid crystal panel;
an out-effective electrode provided in an out-effective region that is a pixel region that does not correspond to the display image around the in-effective region of the liquid crystal panel;
A liquid crystal display device comprising: a light shielding member provided to cover the outer effective electrode and having an offset with respect to the inner effective electrode in a first direction parallel to the outer effective electrode.
(2) The liquid crystal display device according to (1), wherein the offset is provided between an end of the light shielding member and an end of the in-effective electrode in the first direction.
(3) further comprising an irradiation unit that outputs irradiation light to the effective inner area;
The liquid crystal display device according to (2), wherein the offset is a distance corresponding to the wavelength of the irradiation light.
(4) The liquid crystal display device according to (3), wherein the offset is a distance equal to or greater than the square root of the product of the wavelength of the irradiation light and the propagation distance of the wavefront.
(5) Described in (4), further comprising a display data generation unit that generates display data, which is control information for controlling driving of each pixel of the liquid crystal panel, based on the target light intensity distribution of the reproduction surface. liquid crystal display.
(6) The display data generation unit may control the display so that the difference between the light intensity distribution generated on the reproduction surface by the liquid crystal panel reflecting the irradiation light and the target light intensity distribution is within a predetermined allowable range. The liquid crystal display device according to (5), wherein the data for is generated.
(7) The display data generation unit calculates the wavefront propagation using the light intensity distribution and the phase distribution of the effective inner area and the outer effective area, so that the difference is within the allowable range. The liquid crystal display device according to (6), wherein the data for is generated.
(8) The display data generation unit
Using the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the element surface of the liquid crystal panel, the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the reproduction surface are derived. the propagation calculation;
Back propagation calculation for deriving the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the element surface using the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the reproducing surface. The liquid crystal display device according to (7), wherein the display data in which the difference is within the allowable range is generated by repeating and.
(9) The display data generation unit
Using the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the element surface of the liquid crystal panel, the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the reproduction surface are derived. the propagation calculation;
(7) The liquid crystal display device according to (7), wherein the display data is generated such that the difference is within the allowable range by repeating the operation of deriving the gradient of the phase distribution on the element surface so that the difference is small. .
(10) The liquid crystal display device according to any one of (7) to (9), further comprising a control section that controls the effective inner electrodes and the outer effective electrodes based on the display data.
(11) The liquid crystal display device according to (10), wherein the control section sets the voltage of the outer effective electrode within a voltage range used for the inner effective electrode.
(12) The liquid crystal display device according to (11), wherein the control section sets the voltage of the outer effective electrode to a median value of the voltage range used for the inner effective electrode.
(13) The liquid crystal display according to (12), wherein the control section sets the voltage of the non-effective electrode so that the irradiation light applied to the non-effective region is diffracted in a direction away from the internal effective region. Device.
(14) The liquid crystal display device according to (13), wherein the control section sets the voltage of the out-effective electrode such that the phase of the pixels outside the out-of-effective area is delayed.
(15) The liquid crystal display device according to (14), wherein the control unit sets the voltage of the non-effective electrode such that the phase modulation amount increases for pixels located outside the non-effective region.
(16) The liquid crystal display device according to any one of (1) to (15), wherein the liquid crystal panel is a reflective phase modulation element using liquid crystal that is applied to holography.

100 phase modulation element, 111 counter electrode substrate, 112 back plane, 113 panel holder, 114 light blocking portion, 121 effective inner region, 122 effective outer region, 300 liquid crystal display device, 311 display data generation portion, 312 display portion, 321 phase Distribution derivation unit, 331 phase modulation element control unit, 332 illumination unit, 333 phase modulation element, 400 liquid crystal panel, 411 low voltage pixels, 412 high voltage pixels, 501 effective inner area, 502 effective outer area, 511 outer effective area noise, 521 phase modulation element, 522 0th order optical filter, 523 aperture

Claims

an effective inner electrode provided in an effective inner region which is a pixel region corresponding to a display image of the liquid crystal panel;
an out-effective electrode provided in an out-effective region that is a pixel region that does not correspond to the display image around the in-effective region of the liquid crystal panel;
A liquid crystal display device comprising: a light shielding member provided to cover the outer effective electrode and having an offset with respect to the inner effective electrode in a first direction parallel to the outer effective electrode.
2. The liquid crystal display device according to claim 1, wherein the offset is provided between an end of the light shielding member and an end of the inner effective electrode in the first direction.
Further comprising an irradiation unit that outputs irradiation light to the effective inner area,
The liquid crystal display device according to claim 2, wherein the offset is a distance corresponding to the wavelength of the irradiation light.
4. The liquid crystal display device according to claim 3, wherein the offset is a distance equal to or greater than the square root of the product of the wavelength of the irradiation light and the propagation distance of the wavefront.
5. The liquid crystal display according to claim 4, further comprising a display data generation unit that generates display data, which is control information for controlling driving of each pixel of the liquid crystal panel, based on the target light intensity distribution of the reproduction surface. Device.
The display data generation unit generates the display data such that the difference between the light intensity distribution generated on the reproduction surface by the liquid crystal panel reflecting the irradiation light and the target light intensity distribution is within a predetermined allowable range. 6. The liquid crystal display device according to claim 5.
The display data generation unit calculates the display data in which the difference is within the allowable range by performing wavefront propagation calculation using the light intensity distribution and the phase distribution of the effective inner region and the effective outer region. 7. The liquid crystal display device according to claim 6.
The display data generation unit
Using the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the element surface of the liquid crystal panel, the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the reproduction surface are derived. the propagation calculation;
Back propagation calculation for deriving the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the element surface using the light intensity distribution and the phase distribution of the effective inner area and the effective outer area on the reproducing surface. 8. The liquid crystal display device according to claim 7, wherein the display data in which the difference is within the allowable range is generated by repeating and.
The display data generation unit
Using the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the element surface of the liquid crystal panel, the light intensity distribution and the phase distribution of the effective inner region and the effective outer region on the reproduction surface are derived. the propagation calculation;
8. The liquid crystal display device according to claim 7, wherein the display data in which the difference is within the allowable range is generated by repeating an operation of deriving the gradient of the phase distribution on the element surface so that the difference becomes small. .
8. The liquid crystal display device according to claim 7, further comprising a control section that controls said effective inner electrodes and said outer effective electrodes based on said display data.
11. The liquid crystal display device according to claim 10, wherein the control section sets the voltage of the outer effective electrode within a voltage range used for the inner effective electrode.
12. The liquid crystal display device according to claim 11, wherein the control section sets the voltage of the outer effective electrode to a median value of the voltage range used for the inner effective electrode.
13. The liquid crystal display device according to claim 12, wherein the control section sets the voltage of the non-effective electrode so that the irradiation light applied to the non-effective region is diffracted in a direction away from the internal effective region.
14. The liquid crystal display device according to claim 13, wherein the control section sets the voltage of the non-effective electrode such that the phase of the pixels outside the non-effective region is delayed.
15. The liquid crystal display device according to claim 14, wherein the control section sets the voltage of the non-effective electrode such that the phase modulation amount increases in pixels located outside the non-effective region.
The liquid crystal display device according to claim 1, wherein the liquid crystal panel is a reflective phase modulation element using liquid crystal that is applied to holography.