Display panel and display device

Patent metadata

Field	Value
Publication number	US-11270093-B2
Application number	US-202016790314-A
Country	US
Kind code	B2
Filing date	Feb 13, 2020
Priority date	Nov 29, 2019
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The present disclosure provides a display panel and a display device. The display panel includes a plurality of fingerprint recognition circuits. At least one of the plurality of fingerprint recognition circuits includes a light sense signal obtaining unit and a subtracted. The light sense signal obtaining unit is configured to obtain a first light sense voltage value and a second light sense voltage value, the first light sense voltage value is related to a first power voltage value, the second light sense voltage value is related to a second power voltage value, and the first power voltage value is greater than the second power voltage value. The subtracted is configured to subtract the second light sense voltage value from the first light sense voltage value to obtain a light sense data value.

First claim

What is claimed is:

1. A display panel, comprising a plurality of fingerprint recognition circuits, wherein at least one of the plurality of fingerprint recognition circuits comprises a light sense signal obtaining unit and a subtracter,
wherein the light sense signal obtaining unit is configured to obtain a first light sense voltage value and a second light sense voltage value, the first light sense voltage value is related to a first power voltage value, the second light sense voltage value is related to a second power voltage value, and the first power voltage value is greater than the second power voltage value, and
wherein the subtracted is configured to subtract the second light sense voltage value from the first light sense voltage value to obtain a light sense data value.

2. The display panel according to claim 1 , wherein the light sense signal obtaining unit comprises: a first light sense module and a second light sense module;
wherein the first light sense module comprises: a power terminal electrically connected to a first power voltage terminal configured to provide the first power voltage value, and a light sense output terminal electrically connected to a first light sense output terminal configured to output the first light sense voltage value; and
wherein the second light sense module comprises: a power terminal electrically connected to a second power voltage terminal configured to provide the second power voltage value, and a light sense output terminal electrically connected to a second light sense output terminal configured to output the second light sense voltage value.

3. The display panel according to claim 2 , wherein each of the first light sense module and the second light sense module comprises:
a first transistor comprising a first terminal electrically connected to a reset voltage terminal, a second terminal electrically connected to a light sense change node, and a control terminal electrically connected to a reset terminal;
a second transistor comprising a first terminal electrically connected to the power terminal, a control terminal electrically connected to the light sense change node, and a second terminal;
a third transistor comprising a first terminal electrically connected to the second terminal of the second transistor, a second terminal electrically connected to the light sense output terminal, and a control terminal electrically connected to a reading control terminal;
a photodiode comprising a first terminal electrically connected to the light sense change node, and a second terminal electrically connected to a reference voltage terminal; and
a capacitor comprising a first terminal electrically connected to the light sense change node, and a second terminal electrically connected to the reference voltage terminal.

4. The display panel according to claim 1 , wherein
the light sense signal obtaining unit comprises a light sense module,
wherein the light sense module operates in a plurality of fingerprint recognition cycles, and each of the plurality of fingerprint recognition cycles comprises a first phase and a second phase,
wherein, during the first phase, a power terminal of the light sense module provides the first power voltage value, and a light sense output terminal of the light sense module outputs the first light sense voltage value; and
wherein, during the second phase, the power terminal of the light sense module provides the second power voltage value, and the light sense output terminal of the light sense module outputs the second light sense voltage value.

5. The display panel according to claim 4 , wherein the light sense module comprises:
a first transistor comprising a first terminal electrically connected to a reset voltage terminal, a second terminal electrically connected to a light sense change node, and a control terminal electrically connected to a reset terminal;
a second transistor comprising a first terminal electrically connected to the power terminal, a control terminal electrically connected to the light sense change node, and a second terminal;
a third transistor comprising a first terminal electrically connected to the second terminal of the second transistor, a second terminal electrically connected to the light sense output terminal, and a control terminal electrically connected to a reading control terminal;
a photodiode comprising a first terminal electrically connected to the light sense change node and a second terminal electrically connected to a reference voltage terminal; and
a capacitor comprising a first terminal electrically connected to the light sense change node and a second terminal electrically connected to the reference voltage terminal.

6. The display panel according to claim 5 , wherein the light sense module further comprises a gating module electrically connected to a first power voltage terminal, a second power voltage terminal, and the power terminal;
wherein the first power voltage terminal is configured to provide the first power voltage value, and the second power voltage terminal is configured to provide the second power voltage value;
wherein, during the first phase, the gating module allows the first power voltage terminal to be electrically connected to the power terminal; and
wherein, during the second phase, the gating module allows the second power voltage terminal to be electrically connected to the power terminal.

7. The display panel according to claim 6 , wherein the gating module comprises:
a fourth transistor comprising a first terminal electrically connected to the first power voltage terminal, and a second terminal electrically connected to the power terminal; and
a fifth transistor comprising a first terminal electrically connected to the second power voltage terminal, and a second terminal electrically connected to the power terminal,
wherein, during the first phase, the fourth transistor is turned on, the fifth transistor is turned off, and the first power voltage value provided by the first power voltage terminal is transmitted to the power terminal through the fourth transistor, and
wherein, during the second phase, the fifth transistor is turned on, the fourth transistor is turned off, and the second power voltage value provided by the second power voltage terminal is transmitted to the power terminal through the fifth transistor.

8. The display panel according to claim 1 , wherein the first power voltage value is V 1 and the second power voltage value is V 2 , where V 1 >0 and V 2 >0.

9. The display panel according to claim 8 , wherein V 1 >2*V 2 .

10. The display panel according to claim 1 , wherein the first power voltage value is V 1 and the second power voltage value is V 2 , where V 1 >0 and V 2 <0.

11. The display panel according to claim 10 , wherein V 1 =−V 2 .

12. The display panel according to claim 3 , the display panel further comprising a plurality of pixels,
wherein the photodiode of the first light sense module is a first photodiode, and the photodiode in the second light sense module is a second photodiode, and
wherein the first photodiode and the second photodiode in a same fingerprint recognition circuit are located in an area defined by a same pixel of the plurality of pixels.

13. The display panel according to claim 12 , wherein each of the plurality of pixels comprises a plurality of sub-pixels; and
wherein the first photodiode and the second photodiode in the same fingerprint recognition circuit are located in an area defined by a same sub-pixel of the plurality of sub-pixels of one of the plurality of pixels.

14. The display panel according to claim 12 , where

Assignees

• Xiamen Tianma Micro Electronics Co Ltd

Inventors

• Lai Meng
• Lu Lifeng
• Zhuang Zhilong
• Huang Jiancai
• Xu Yumin
• Yang Xianyan

Classifications

• G06V40/1318 Primary

  using electro-optical elements or layers, e.g. electroluminescent sensing · CPC title

• H10F39/811

  Interconnections · CPC title

• H10F39/198

  Contact-type image sensors [CIS] · CPC title

• H10F39/803

  Pixels having integrated switching, control, storage or amplification elements · CPC title

• H10F39/80 Primary

  Constructional details of image sensors · CPC title