Optical display system, control method and display device

Patent metadata

Field	Value
Publication number	US-12235449-B2
Application number	US-202117627087-A
Country	US
Kind code	B2
Filing date	Mar 18, 2021
Priority date	Apr 30, 2020
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

An optical display system, a control method, and a display device, relates to the field of display technology. The optical display system comprises a display screen a first light splitting unit disposed at a display side of the display screen; a first imaging unit comprising a light splitting film disposed at a light-incident surface of the first imaging unit; a second light splitting unit disposed at a light emission side of the first imaging unit; a phase modulation unit disposed at least in a light path from the first imaging unit to the second light splitting unit; wherein, the first-type polarized light transmitted from the first light splitting unit is transmitted from a light emission side of the second light splitting unit, after being turned back multiple times between the first imaging unit and the second light splitting unit.

First claim

The invention claimed is:

1. An optical display system, wherein the system comprises:
a display screen;
a first light splitting unit, disposed at a display side of the display screen, wherein the first light splitting unit is configured to transmit a first-type polarized light and block a second-type polarized light, and light emitted from the display screen is converted into the first-type polarized light after passing through the first light splitting unit;
a first imaging unit, disposed at a light emission side of the first light splitting unit, wherein the first imaging unit comprises a light splitting film disposed at a light-incident surface of the first imaging unit, and the light splitting film is configured to transmit light and reflect light;
a second light splitting unit, disposed at a light emission side of the first imaging unit, wherein the second light splitting unit is configured to transmit the first-type polarized light and reflect the second-type polarized light; and
a phase modulation unit, disposed at least in a light path from the first imaging unit to the second light splitting unit, wherein the phase modulation unit is configured to modulate a phase of light;
wherein, the first-type polarized light transmitted from the first light splitting unit travels between the first imaging unit and the second light splitting unit as follows: reaching the second light splitting unit after passing through the first imaging unit and the phase modulation unit in sequence; being reflected back to the phase modulation unit by the second light splitting unit, and transmitted, after being modulated by the phase modulation unit, to the light splitting film of the first imaging unit; being reflected to the phase modulation unit by the light splitting film, and transmitting, after being modulated by the phase modulation unit, from the light emission side of the second light splitting unit.

2. The optical display system according to claim 1 , wherein the phase modulation unit comprises a first quarter-wave plate and a second quarter-wave plate;
the first quarter-wave plate is disposed in a light path from the first light splitting unit to the first imaging unit; the second quarter-wave plate is disposed in the light path from the first imaging unit to the second light splitting unit.

3. The optical display system according to claim 2 , wherein the optical display system further comprises a second imaging unit disposed at the light emission side of the second light splitting unit.

4. The optical display system according to claim 3 , wherein the first imaging unit further comprises a first lens, the light splitting film is disposed at a light-incident surface of the first lens; and
the second imaging unit comprises a second lens.

5. The optical display system according to claim 4 , wherein the first lens is a glass lens, and the second lens is a plastic lens.

6. The optical display system according to claim 4 , wherein the second imaging unit further comprises a metal wire-grid film disposed at a light-incident surface of the second lens; and
the metal wire-grid film is configured to be capable to transmit the first-type polarized light and capable to absorb the second-type polarized light.

7. The optical display system according to claim 1 , wherein the phase modulation unit is disposed in the light path from the first imaging unit to the second light splitting unit; and
the phase modulation unit is further configured to modulate the phase of light at different angles in different display periods.

8. The optical display system according to claim 7 , wherein the phase modulation unit comprises a liquid crystal phase modulator or a removable half-wave plate.

9. The optical display system according to claim 1 , wherein the first light splitting unit comprises a first polaroid or a second polaroid;
the first polaroid is configured to transmit the first-type polarized light and reflect the second-type polarized light; and
the second polaroid is configured to be capable to transmit the first-type polarized light and capable to absorb the second-type polarized light.

10. The optical display system according to claim 1 , wherein the first imaging unit further comprises a first lens, and the light splitting film is disposed at a light-incident surface of the first lens.

11. The optical display system according to claim 1 , wherein the second light splitting unit comprises a third polaroid, and the third polaroid is configured to transmit the first-type polarized light and reflect the second-type polarized light.

12. The optical display system according to claim 1 , wherein the first-type polarized light is P-type polarized light, the second-type polarized light is S-type polarized light;
or,
the first-type polarized light is the S-type polarized light, the second-type polarized light is the P-type polarized light.

13. A display device, wherein, the display device comprises the optical display system according to claim 1 .

14. The display device according to claim 13 , wherein the display device is a virtual reality display device or an augmented reality display device.

15. The display device according to claim 13 , wherein the display device comprises a folded optical system.

16. A method for controlling the optical display system according to claim 7 , wherein the method comprises:
at a first time period, inputting a first focal plane image signal to the display screen;
controlling the display screen to display a first focal plane image; wherein the light emitted from the display screen forms an enlarged image corresponding to a first focal length after passing through the first light splitting unit and the first imaging unit in sequence;
controlling, at the first time period, the phase modulation unit to have a zero-degree phase modulation value of the light transmitted by the first imaging unit; wherein light modulated by the phase modulation unit is emitted by the second light splitting unit;
at a second time period, inputting a second focal plane image signal to the display screen; and
controlling the display screen to display a second focal plane image; wherein the light emitted from the display screen is converted into the first-type polarized light after passing through the first light splitting unit; the first-type polarized light transmitted from the first light splitting unit travels between the first imaging unit and the second light splitting unit as follows: reaching the second light splitting unit after passing through the first imaging unit and the phase modulation unit in sequence; being reflected back to the phase modulation unit by the second light splitting unit, and transmitted, after being modulated by the phase modulation unit, to the light splitting film of the first imaging unit; being reflected to the phase modulation unit by the light splitting film, and transmitting, after being modulated by the phase modulation unit, from the light emission side of the second light splitting unit, and forms an enlarged image corresponding to a second focal length.

17. The method for controlling the optical display system according to claim 16 , wherein the phase modulation unit comprises a removable half-wave plate that does not modulate phase of light in the first time period;
the step of controlling, at the first time period, the phase modulation unit to have a zero-degree phase modulation value of the light transmitted by the first imaging unit comprises:
at the first time period, removing the half-wave plate from the light path from the first imaging

Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Wang Chenru
• Dong Ruijun
• Li Ke
• Wu Yulong
• Chen Lili
• Zhang Hao
• Qu Feng

Classifications

• G02F1/13731

  based on a field-induced phase transition (G02F1/13781 takes precedence) · CPC title

• G02B27/283

  used for beam splitting or combining · CPC title

• G02B5/3058

  comprising electrically conductive elements, e.g. wire grids, conductive particles · CPC title

• G02B30/25

  using polarisation techniques · CPC title

• G02B2027/0134

  of stereoscopic type · CPC title