Photodetector and display device

Patent metadata

Field	Value
Publication number	US-10877351-B2
Application number	US-202016774827-A
Country	US
Kind code	B2
Filing date	Jan 28, 2020
Priority date	Mar 14, 2017
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

According to one embodiment, a photodetector includes a sensor unit including at least one photosensor, a liquid crystal element including a first substrate includes a plurality of first control electrodes, a second substrate including a second control electrode, and a liquid crystal layer held between the first substrate and the second substrate, a liquid crystal controller which controls a voltage to be applied to the liquid crystal layer for forming a first lens that is opposed to the photosensor in the liquid crystal layer, and a sensor controller which controls the sensor.

First claim

What is claimed is:

1. A photodetector comprising:
a sensor unit comprising at least one photosensor;
a liquid crystal element comprising a first substrate comprising a plurality of first control electrodes, a second substrate comprising a second control electrode, and a liquid crystal layer held between the first substrate and the second substrate;
a liquid crystal controller which controls a voltage to be applied to the liquid crystal layer for forming a first lens that is opposed to the photosensor in the liquid crystal layer;
a sensor controller which controls the sensor unit; and
a memory unit which stores a first voltage for forming the first lens of a first shape in the liquid crystal layer, and a second voltage for forming the first lens of a second shape different from the first shape in the liquid crystal layer, wherein
the sensor controller measures an output from the photosensor when the first voltage is applied to the liquid crystal layer, measures an output from the photosensor when the second voltage is applied to the liquid crystal layer, compares the outputs measured at the respective timings, and determines an incident direction of light according to a shape of the first lens at a timing when a maximum output is obtained.

2. The photodetector of claim 1 , wherein each of the first control electrodes is a strip electrode.

3. The photodetector of claim 1 , wherein the first shape is symmetrical with respect to a normal of the liquid crystal element, and the second shape is unsymmetrical with respect to the normal of the liquid crystal element.

4. The photodetector of claim 1 , wherein a thickness of the liquid crystal layer is 10 to 100 μm.

5. The photodetector of claim 1 , wherein the first substrate further comprises a first insulating substrate, a first insulating film, and a first alignment film,
the photosensor is arranged between the first insulating substrate and the first insulating film,
the first control electrodes are located on the first insulating film and are covered with the first alignment film,
the first control electrodes are located closer to the liquid crystal layer than the photosensor, and
a space between two first control electrodes overlaps the photosensor.

6. The photodetector of claim 5 , wherein the second substrate further comprises a second insulating substrate and a second alignment film, and
the second control electrode is arranged between the second insulating substrate and the second alignment film.

7. The photodetector of claim 6 , wherein the second substrate further comprises a light-shielding body,
the light-shielding body is arranged between the second insulating substrate and the second alignment film, and includes an opening,
the opening is formed at a position opposed to the photosensor, and
the second control electrode is arranged between the second insulating substrate and the second alignment film in the opening.

Assignees

• Japan Display Inc

Inventors

• Nakanishi Takayuki
• Yata Tatsuya
• Koito Takeo

Classifications

• G02F1/29 Primary

  for the control of the position or the direction of light beams, i.e. deflection · CPC title

• G02F1/13318

  Circuits comprising a photodetector · CPC title

• G02F1/13312

  Circuits comprising photodetectors for purposes other than feedback · CPC title

• G02F1/133345

  Insulating layers (G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence) · CPC title

• G02F2201/16

  series; tandem · CPC title