Photosensitive module, photosensitive device and display panel

• US 10,503,954 B2
• Filed: 04/14/2018
• Issued: 12/10/2019
• Est. Priority Date: 08/23/2017
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Xu, Rui, Wang, Haisheng, Liu, Yingming, Gu, Pinchao, Li, Changfeng, Cao, Xueyou, Liu, Wei
• Primary Examiner(s): Malsawma, Lex H
• Application Number:
  US15/953,431
• Publication Number:
  US 20190065812A1
• Time in Patent Office: 605 Days
• Field of Search: None
• CPC Class Codes: G02B 6/0016 Grooves, prisms, gratings, scattering particles or rough surfaces
• CPC Class Codes: G02B 6/0023 provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source
• CPC Class Codes: G02B 6/0035 provided on the surface of the light guide or in the bulk of it
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing
• CPC Class Codes: G06V 40/1324 by using geometrical optics, e.g. using prisms G06V40/1312 takes precedence
• CPC Class Codes: H01L 27/14625 Optical elements or arrangements associated with the device

Abstract

A photosensitive module includes a plurality of photosensitive cells. Each of the photosensitive cells includes a selective light director having a first surface including a light entry region and a light exit region different from the light entry region, the selective light director being configured to selectively direct a collimated portion of light incident towards the light entry region to the light exit region to exit from the selective light director; and a photoelectric converter arranged in the light exit region and having a light receiving surface facing the light exit region to receive the collimation portion of the light exiting from the selective light director.

Claims

1. A photosensitive module comprising:

a plurality of photosensitive cells each comprising;

a selective light director having a first surface, the first surface comprising a light entry region and a light exit region different from the light entry region, the selective light director being configured to selectively direct a collimated portion of light incident towards the light entry region to the light exit region to exit from the selective light director, the collimated portion of the light having an incidence angle with respect to a normal to the first surface that is less than a threshold; and

a photoelectric converter arranged in the light exit region and having a light receiving surface facing the light exit region to receive the collimated portion of the light exiting from the selective light director, the photoelectric converter being configured to generate an electrical signal based on an intensity of the received collimated portion of the light.

2. The photosensitive module of claim 1, further comprising a light source arranged on the first surface of one of the selective light directors to emit light in a direction away from the first surface.

3. The photosensitive module of claim 1, further comprising a processor configured to receive the electrical signal from at least a portion of the photosensitive cells and generate an image from the received electrical signals.

4. The photosensitive module of claim 1, wherein the selective light director comprises:

an optical waveguide plate providing the first surface;

a first holographic diffraction grating arranged in the light entry region for coupling the collimated portion of the light into the optical waveguide plate such that the collimated portion of the light propagates within the optical waveguide plate to the light exit region; and

a second holographic diffraction grating arranged in the light exit region for coupling the collimated portion of the light propagating to the light exit region out of the optical waveguide plate.

5. The photosensitive module of claim 4, wherein each of the photosensitive cells further comprises a collimator comprising at least one light transmission channel, and wherein the collimator is arranged on the first holographic diffraction grating to allow substantially only the collimated portion of the light incident towards the light entry region to pass through the at least one light transmission channel to be incident on the first holographic diffraction grating.

6. The photosensitive module of claim 5, wherein the collimator comprises a plurality of light absorbing strips parallel to and spaced apart from one other, and wherein the light absorbing strips are arranged parallel to the normal to the first surface such that a gap between each two directly adjacent ones of the light absorbing strips forms a corresponding one of the light transmission channels.

7. The photosensitive module of claim 5, wherein the collimator comprises a first light absorbing plate and a second light absorbing plate parallel to and spaced apart from each other, wherein the first light absorbing plate and the second light absorbing plate are arranged perpendicular to the normal to the first surface and are each provided with at least one opening extending in a direction parallel to the normal, and wherein the at least one opening of the first light absorbing plate and the at least one opening of the second light absorbing plate are aligned in a direction parallel to the normal to form the at least one light transmission channel.

8. The photosensitive module of claim 4, wherein at least a portion of the plurality of photosensitive cells is formed in one piece.

9. The photosensitive module of claim 4, wherein the selective light directors of the plurality of photosensitive cells are spaced apart from one another.

10. The photosensitive module of claim 1, wherein the photoelectric converter is provided, at an outer surface thereof other than the light receiving surface, with a light shielding layer.

11. The photosensitive module of claim 1, wherein each of the photosensitive cells further comprises a switch transistor arranged on a side of the photoelectric converter away from the selective light director.

12. The photosensitive module of claim 11, wherein the switch transistor comprises an active layer and a light shielding block covering the active layer to protect the active layer from the collimated portion of the light exiting from the selective light director.

13. A photosensitive device comprising the photosensitive module of claim 1.

14. A display panel comprising:

a base substrate on which a plurality of pixel units are provided;

a cover plate disposed opposite to the base substrate; and

a photosensitive module disposed between the base substrate and the cover plate, the photosensitive module comprising a plurality of photosensitive cells each comprising;

a selective light director having a first surface, the first surface comprising a light entry region and a light exit region different from the light entry region, the selective light director being configured to selectively direct a collimated portion of light incident towards the light entry region to the light exit region to exit from the selective light director, the collimated portion of the light having an incidence angle with respect to a normal to the first surface that is less than a threshold; and

a photoelectric converter arranged in the light exit region and having a light receiving surface facing the light exit region to receive the collimated portion of the light exiting from the selective light director, the photoelectric converter being configured to generate an electrical signal based on an intensity of the received collimated portion of the light,

wherein the photosensitive module is arranged such that the first surface of the selective light director faces the cover plate.

15. The display panel of claim 14, wherein the photosensitive module further comprises a light source configured to emit light in a direction away from the first surface of the selective light director.

16. The display panel of claim 15, wherein the photosensitive module is disposed within a display area of the display panel where the pixel units are provided, and wherein the light source, the pixel units and the photoelectric converters are arranged on the first surfaces of the selective light directors.

17. The display panel of claim 14, wherein the photosensitive module is disposed within a display area of the display panel where the pixel units are provided, wherein each of the pixel units is an organic light emitting diode pixel unit comprising an organic light emitting diode, and wherein first ones of the pixel units are disposed above respective ones of the photosensitive cells such that the organic light emitting diodes of the first pixel units emit light in a direction away from the first surfaces of the selective light directors.

18. The display panel of claim 17, wherein the selective light director comprises:

an optical waveguide plate providing the first surface;

a first holographic diffraction grating arranged in the light entry region for coupling the collimated portion of the light into the optical waveguide plate such that the collimated portion of the light propagates within the optical waveguide plate to the light exit region; and

a second holographic diffraction grating arranged in the light exit region for coupling the collimated portion of the light propagating to the light exit region out of the optical waveguide plate.

19. The display panel of claim 18, wherein the selective light director further comprises a collimator comprising at least one light transmission channel, and wherein the collimator is arranged on the first holographic diffraction grating to allow substantially only the collimated portion of the light incident towards the light entry region to pass through the at least one light transmission channel to be incident on the first holographic diffraction grating.

20. The display panel of claim 19, further comprising an insulating layer disposed between the first pixel units and the respective photosensitive cells, wherein the organic light emitting diode comprises a first electrode layer, an organic light emitting material layer, and a second electrode layer stacked on top of each other in a direction far away from the base substrate, and wherein the at least one light transmission channel extends from the first holographic diffraction grating to one selected from the group consisting of the second electrode layer and the insulating layer.