# US 12,216,866 B2 · Fingerprint sensor and display device including the same

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- Number: US 12,216,866 B2
- Document ID: US12216866B2
- Status: Granted
- Kind: B2
- Application number: 18/301,974
- Filed: 2023-04-17
- Published: 2023-08-10
- Granted: 2025-02-04
- Earliest claimed: 2017-11-17
- Assignees: Samsung Display Co., Ltd.
- Applicants: Samsung Display Co., Ltd.
- Inventors: Ji Sun Kim; Mu Kyung Jeon
- Web page: https://patentgrep.com/patent/US12216866B2

## CPC

- G06F 3/044: by capacitive means
- G06F 3/0416: {Control or interface arrangements specially adapted for digitisers}
- G06V 10/147: Details of sensors, e.g. sensor lenses (fingerprint or palmprint sensors G06V40/13; vascular sensors G06V40/145; eye sensors G06V40/19)
- G06V 40/1306: {non-optical, e.g. ultrasonic or capacitive sensing}
- G06F 2203/04112: Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING

## Abstract

A fingerprint sensor includes a sensor pixel arranged in a sensing area, including a pixel electrode coupled to a first node; a first transistor coupled between the first node and a first or second power line, the first transistor including a first gate electrode coupled to a first scan line and a second gate electrode opposite to the first gate electrode; a first capacitor coupled between the first node and a second scan line; a second transistor coupled between a readout line and the first power line, the second transistor including a first gate electrode coupled to the first node and a second gate electrode opposite to the first gate electrode; and a third transistor coupled between the second transistor and the first power line, the third transistor including a first gate electrode coupled to the second scan line and a second gate electrode opposite to the first gate electrode.

## Claims

### Claim 1

A fingerprint sensor comprising:
at least one sensor pixel arranged in a sensing area,
wherein the sensor pixel includes:
a pixel electrode coupled to a first node;
a first transistor including a source electrode and a drain electrode, the first transistor being coupled between the first node and a first power line, the first transistor including a first gate electrode coupled to a first scan line and a second gate electrode opposite to the first gate electrode, the second gate electrode being coupled to the first power line;
a first capacitor coupled between the first node and a second scan line, and comprising a first electrode and a second electrode, the second electrode comprising a portion of the pixel electrode;
a second transistor coupled between a readout line and a second power line, the second transistor including a first gate electrode coupled to the first node and a second gate electrode opposite to the first gate electrode; and
a third transistor coupled between the second transistor and the second power line, the third transistor including a first gate electrode coupled to the second scan line and a second gate electrode opposite to the first gate electrode,
wherein the source electrode of the first transistor is electrically connected to the second gate electrode of the first transistor and the first power line,
wherein the drain electrode of the first transistor is electrically connected to the pixel electrode and the second electrode of the first capacitor,
wherein the first transistor is electrically coupled between the first power line and the pixel electrode along a first current path, and the second transistor is electrically coupled between the readout line and the second power line along a second current path separate from the first current path, and
wherein the drain electrode of the first transistor is electrically coupled between the pixel electrode and the source electrode of the first transistor.

### Claim 2 (depends on 1)

The fingerprint sensor of claim 1, wherein the portion of the pixel electrode overlaps with, and entirely surrounds a periphery of, the first electrode of the first capacitor in a plan view.

### Claim 3 (depends on 1)

The fingerprint sensor of claim 1, wherein the first electrode of the first capacitor is electrically connected to the first gate electrode of the third transistor and the second scan line via at least one contact hole.

### Claim 4 (depends on 1)

The fingerprint sensor of claim 1, wherein the second electrode of the first capacitor overlaps the first electrode of the first capacitor in a plan view.

### Claim 5 (depends on 1)

The fingerprint sensor of claim 1, wherein the second gate electrode of the second transistor is coupled to the first gate electrode of the second transistor.

### Claim 6 (depends on 1)

The fingerprint sensor of claim 1, wherein the second gate electrode of the second transistor is coupled to a control line.

### Claim 7 (depends on 1)

The fingerprint sensor of claim 1, wherein the source electrode of the first transistor is directly connected to the second gate electrode of the first transistor and the first power line.

### Claim 8

A fingerprint sensor comprising:
at least one sensor pixel arranged in a sensing area,
wherein the sensor pixel includes:
a pixel electrode coupled to a first node;
a first transistor including a source electrode and a drain electrode, the first transistor being coupled between the first node and a first power line, the first transistor including a first gate electrode coupled to a first scan line and a second gate electrode opposite to the first gate electrode, the second gate electrode being coupled to the first power line;
a first capacitor coupled between the first node and a second scan line, and comprising a first electrode and a second electrode, the second electrode comprising a portion of the pixel electrode;
a second transistor coupled between a readout line and a second power line, the second transistor including a first gate electrode coupled to the first node and a second gate electrode opposite to the first gate electrode; and
a third transistor coupled between the second transistor and the second power line, the third transistor including a first gate electrode coupled to the second scan line and a second gate electrode opposite to the first gate electrode,
wherein the source electrode of the first transistor is directly connected to the second gate electrode of the first transistor and the first power line,
wherein the drain electrode of the first transistor is directly connected to the pixel electrode and is electrically connected to the second electrode of the first capacitor.

### Claim 9

A display device comprising:
a display panel including display pixels arranged in a display area; and
a fingerprint sensor including scan lines, readout lines, at least one power line, and sensor pixels, which are arranged in a sensing area,
wherein at least one of the sensor pixels includes:
a pixel electrode coupled to a first node;
a first transistor including a source electrode and a drain electrode, the first transistor being coupled between the first node and a first power line, the first transistor including a first gate electrode coupled to a first scan line and a second gate electrode opposite to the first gate electrode, the second gate electrode being coupled to the first power line;
a first capacitor coupled between the first node and a second scan line;
a second transistor coupled between a readout line and a second power line, the second transistor including a first gate electrode coupled to the first node and a second gate electrode opposite to the first gate electrode; and
a third transistor coupled between the second transistor and the second power line, the third transistor including a first gate electrode coupled to the second scan line and a second gate electrode opposite to the first gate electrode,
wherein the source electrode of the first transistor is electrically connected to the second gate electrode of the first transistor and the first power line,
wherein the drain electrode of the first transistor is electrically connected to the pixel electrode and a second electrode of the first capacitor,
wherein the first transistor is electrically coupled between the first power line and the pixel electrode along a first current path, and the second transistor is electrically coupled between the readout line and the second power line along a second current path separate from the first current path, and
wherein the drain electrode of the first transistor is electrically coupled between the pixel electrode and the source electrode of the first transistor.