# US 2020/0401780 A1 · Fingerprint sensor and display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2020/0401780 A1
- Document ID: US20200401780A1
- Status: Published application
- Kind: A1
- Application number: 16/772,463
- Filed: 2018-11-26
- Published: 2020-12-24
- Earliest claimed: 2017-12-28
- Assignees: CONNECTEC JAPAN Corporation; Fujikin Incorporated
- Applicants: CONNECTEC JAPAN Corporation; Fujikin Incorporated
- Inventors: Hiroshi KOMATSU; Akane SUZUKI; Jun KIMURA; Kensuke KOJIMA
- Web page: https://patentgrep.com/patent/US20200401780A1

## CPC

- G06V 40/1318: {using electro-optical elements or layers, e.g. electroluminescent sensing}
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING

## Abstract

A fingerprint sensor for a display device capable of suppressing loss of light due to diffraction of light and a display device with this fingerprint sensor are provided. A fingerprint sensor for a display device having a plurality of photosensors arranged in a matrix, each of the photosensors has a semiconductor film for converting incident light into an electric signal, and a bottom gate electrode as a light shielding film arranged on a lower layer side of the semiconductor film for blocking incident light from the lower layer side to the semiconductor film, wherein the bottom gate electrode has four corner portions in an outer contour shape in a top view, and each of the corner portions is rounded.

## Claims

### Claim 1

A fingerprint sensor for a display device, having a plurality of photosensors arranged in a matrix,
each of the photosensors comprising:
a semiconductor film for converting incident light into an electrical signal; and
a light shielding film disposed on a lower layer side than the semiconductor film and for blocking incidence of light to the semiconductor film from the lower layer side,
wherein an outer contour shape in a top view of the light shielding film is rounded to suppress diffraction of light from the lower layer side.

### Claim 2

A fingerprint sensor for a display device, having a plurality of photosensors arranged in a matrix,
each of the photosensors comprising:
a semiconductor film for converting incident light into an electrical signal, and
a light shielding film disposed on a lower layer side than the semiconductor film and for blocking incidence of light to the semiconductor film from the lower layer side,
wherein the light shielding film has four corner portions in outer contour shape in a top view,
each of the four corner portions has a radius of curvature that exceeds a radius of curvature that may occur at corner portions of the light shielding film due to a forming process including a photolithography process.

### Claim 3 (depends on 2)

The fingerprint sensor according to claim 2, wherein a radius of curvature of each of the corner portions is 2 μm or more.

### Claim 4 (depends on 1)

The fingerprint sensor according to claim 1, wherein the outer contour shape in a top view of the semiconductor film is rounded to correspond to the light shielding film.

### Claim 5

A fingerprint sensor for a display device, having a plurality of photosensors arranged in a matrix,
each of the photosensors comprising:
a semiconductor film for converting incident light into an electrical signal; and
a light shielding film disposed on a lower layer side than the semiconductor film, and for blocking incidence of light from the lower layer side to the semiconductor film,
wherein an outer contour shape of the light-shielding film in a top view is substantially entirely formed by curves.

### Claim 6 (depends on 5)

The fingerprint sensor of claim 5, wherein the outer contour shape in a top view of the semiconductor film is substantially entirely formed by curves to correspond to the outer contour shape of the light shielding film.

### Claim 7 (depends on 5)

The fingerprint sensor according to claim 5, wherein the light shielding film has a substantially circular outer contour shape in a top view.

### Claim 8 (depends on 7)

The fingerprint sensor according to claim 7, wherein the outer contour shape of the semiconductor film in a top view is substantially concentric with the light shielding film.

### Claim 9

(canceled)