Holographic display device and display method thereof

Patent metadata

Field	Value
Publication number	US-12259685-B2
Application number	US-202218291280-A
Country	US
Kind code	B2
Filing date	Jul 27, 2022
Priority date	Aug 12, 2021
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A holographic display device and a display method thereof. The holographic display device comprises a backlight module and two liquid crystal modules. The backlight module is used for providing coherent light; the two liquid crystal modules are located on the light exit side of the backlight module, and the two liquid crystal modules are stacked; one of the two liquid crystal modules is used for performing amplitude modulation on incident light, and the other one is used for performing phase modulation on incident light. In this way, the complex amplitude of exit light is adjusted, and the quality of a reconstructed image is improved.

First claim

What is claimed is:

1. A holographic display device, comprising:
a backlight module, configured to provide coherent light;
a first liquid crystal module, located at a light-emitting side of the backlight module; and
a second liquid crystal module located at a side of the first liquid crystal module facing away from the backlight module;
wherein the first liquid crystal module is configured for performing amplitude modulation on incident light, and the second liquid crystal module is configured for performing phase modulation on the incident light;
the first liquid crystal module and the second liquid crystal module comprise:
a first substrate;
a second substrate, disposed opposite to the first substrate;
a third substrate, located at a side of the second substrate facing away from the first substrate;
a first liquid crystal layer, located between the first substrate and the second substrate;
a second liquid crystal layer, located between the second substrate and the third substrate;
a first polarization layer, located at a side of the first liquid crystal module facing away from the second liquid crystal module;
a second polarization layer, located at a side of the second liquid crystal module facing away from the first liquid crystal module;
a first orientation layer and a second orientation layer located at two sides of the first liquid crystal layer, respectively; and
a third orientation layer and a fourth orientation layer located at two sides of the second liquid crystal layer, respectively;
wherein a polarization direction of the first polarization layer is perpendicular to a polarization direction of the second polarization layer;
an orientation of first orientation layer is perpendicular to an orientation of the second orientation layer, and an orientation of the third orientation layer is parallel to an orientation of the fourth orientation layer;
the orientation of the first orientation layer is parallel to the polarization direction of the first polarization layer; and
the orientation of the fourth orientation layer is parallel to the polarization direction of the second polarization layer.

2. The holographic display device according to claim 1 , wherein a thickness of the second substrate is less than 200 μm.

3. The holographic display device according to claim 1 , wherein the first liquid crystal module further comprises a plurality of first sub-pixel units, and the second liquid crystal module further comprises a plurality of second sub-pixel units;
wherein one first sub-pixel unit corresponds to at least one second sub-pixel unit.

4. The holographic display device according to claim 3 , wherein second sub-pixel units corresponding to the first sub-pixel unit are distributed in central symmetry with respect to a central point of the first sub-pixel unit.

5. The holographic display device according to claim 4 , wherein an orthographic projection of the central point of an opening region of the first sub-pixel unit on the backlight module coincides with an orthographic projection, on the backlight module, of a central point of an opening region of a second sub-pixel unit located in a center among corresponding second sub-pixel units.

6. The holographic display device according to claim 3 , wherein a size of the opening region of the first sub-pixel unit is greater than a size of the opening region of the second sub-pixel unit; and
wherein the size of the opening region of the first sub-pixel unit is greater than or equal to 3 μm, and the size of the opening region of the second sub-pixel unit is greater than or equal to 3 μm.

7. The holographic display device according to claim 3 , wherein the first liquid crystal module and the second liquid crystal module further comprise:
a light shielding layer, located at a side of the third substrate facing the second liquid crystal layer and comprising a plurality of openings exposing opening regions of the second sub-pixel units; and
a plurality of light-shield support pillars, located between the second substrate and the third substrate and arranged along edges of the opening regions of the second sub-pixel units according to a pattern of the light shielding layer.

8. The holographic display device according to claim 7 , wherein an orthographic projection of the light shielding layer on the second substrate completely covers an orthographic projection of each light-shield support pillar on the second substrate.

9. The holographic display device according to claim 7 , wherein a shape of each opening of the light shielding layer is a square, a rhombus, a circle, or a regular hexagon.

10. The holographic display device according to claim 1 , wherein edges of same sides of the first substrate, the second substrate and the third substrate are provided with a positioning hole, and orthographic projections of positioning holes of the first substrate, the second substrate and the third substrate on the backlight module overlap one another.

11. The holographic display device according to claim 1 , wherein emergent light of the backlight module is laser light; and
wherein the backlight module at least provides laser light of two colors and is configured to emit laser light of different colors in time division.

12. The holographic display device according to claim 1 , further comprising:
a processor, connected with the backlight module, the first liquid crystal module, and the second liquid crystal module and configured to control the backlight module to emit the coherent light in a set timing according to holographic image data and provide a driving signal to the first liquid crystal module and the second liquid crystal module, to drive the first liquid crystal module and the second liquid crystal module according to the driving signal to modulate the incident light to achieve holographic display.

13. A display method of a holographic display device, comprising:
receiving holographic data of an image to be displayed during holographic display;
providing coherent light by a backlight module; and
performing amplitude modulation and phase modulation on incident light by two liquid crystal modules respectively according to the holographic data to display a corresponding reconstructed image;
wherein the two liquid crystal modules comprise a first substrate and a second substrate disposed opposite to each other, and a third substrate located at a side of the second substrate facing away from the first substrate; edges of same sides of the first substrate, the second substrate and the third substrate are provided with a positioning hole; and the substrates comprised in the two liquid crystal modules are aligned by:
disposing a receiver at a side of the first substrate facing away from the second substrate, and disposing an emitter at a side of the third substrate facing away from the second substrate;
controlling the emitter to emit laser light to the receiver through positioning holes of the first substrate, the second substrate and the third substrate; and
completing an alignment operation for the substrates of the two liquid crystal modules in a case that a difference between an intensity of the laser light received by the receiver and an intensity of the laser light emitted by the emitter is less than a preset threshold.

14. The display method according to claim 13 , wherein the holographic display device comprises a processor connected with the backlight module and the two liquid crystal modules;
the processor is configured to receive the holographic data of the image to be displayed and generate, according to the holographic data, a driving signal used fo

Assignees

• Boe Technology Group Co Ltd

Inventors

• Wang Qian
• Xue Gaolei
• Li Zhongxiao
• Liang Pengxia

Classifications

• G09G2320/0209

  Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display · CPC title

• G09G3/3607

  for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels (display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127) · CPC title

• G09G3/3413

  Details of control of colour illumination sources · CPC title

• G09G3/003

  to produce spatial visual effects · CPC title

• G03H2225/34

  Amplitude and phase coupled modulation · CPC title