US-12620356-B2 - Display device

US12620356B2US 12620356 B2US12620356 B2US 12620356B2US-12620356-B2

Abstract

A display device including: scan lines including first and second scan lines; pixels connected to the scan lines; photo sensors connected to some of the scan lines, the photo sensors including a first photo sensor connected to the first scan line and a readout line, and a second photo sensor connected to the second scan line and the readout line; a scan driver to provide scan signals to the scan lines; and a readout circuit to receive, through the readout line, detection signals which are outputted from the photo sensors in response to the scan signals, wherein, while the scan signals are provided to the first and second scan lines, the readout circuit samples a detection signal of one of the first photo sensor and the second photo sensor without sampling a detection signal of the other one of the first photo sensor and the second photo sensor.

Inventors

Il Nam Kim
Seung Hyun Moon
Dong Wook Yang
Hyun Dae Lee
Kang Bin Jo
Go Eun CHA
Hee Chul Hwang

Assignees

SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20240930
Priority Date: 20220509

Claims (20)

1 . A display device, comprising: a plurality of pixels; a plurality of photo sensors; a scan driver configured to provide scan signals to the plurality of photo sensors and the plurality of pixels through scan lines; and a readout circuit configured to receive detection signals which are outputted from the plurality of photo sensors in response to the scan signals through readout lines, wherein the readout circuit receives the detection signals from all of the plurality of photo sensors during a plurality of frame periods, and in each frame period of the plurality of frame periods, the plurality of pixels receive data signals and some of the plurality of photo sensors output the detection signals.
2 . The display device according to claim 1 , wherein each of the plurality of photo sensors includes a sensor circuit and a light receiving element.
3 . The display device according to claim 2 , wherein the sensor circuit and the light receiving element of each of the plurality of photo sensors are arranged in a first direction.
4 . The display device according to claim 3 , wherein the sensor circuit includes a sensor transistor providing a detection signal to a readout line to which the sensor circuit is connected when turned on by a first scan signal among the scan signals.
5 . The display device according to claim 4 , wherein in each of the plurality of frame periods, the readout circuit receives detection signals from as many photo sensors as a number obtained by dividing a number of all the plurality of photo sensors in the display device by a number of the plurality of frame periods.
6 . The display device according to claim 5 , wherein the readout circuit receives a detection signal from a first photo sensor during a first frame period, and receives a detection signal from a second photo sensor during a second frame period, wherein the plurality of photo sensors comprise the first photo sensor connected to a first scan line and the readout line, and the second photo sensor connected to a second scan line and the readout line, and wherein the first scan line and the second scan line are adjacent to each other.
7 . The display device according to claim 6 , wherein the readout circuit comprises: an integrating circuit configured to integrate a signal flowing through the readout lines; a first sampling circuit configured to sample an output of the integrating circuit and generate a first sampling signal; a second sampling circuit configured to sample the output of the integrating circuit and generate a second sampling signal; and an analog-digital converter configured to output a digital value corresponding to a difference between the first sampling signal and the second sampling signal.
8 . The display device according to claim 7 , wherein, during a first period in which a scan signal is applied to the first scan line, the integrating circuit and the readout line are reset, wherein, in a second period, the first sampling circuit generates the first sampling signal, and wherein, in the third period, a scan signal is applied to the second scan line and the second sampling circuit generates the second sampling signal.
9 . The display device according to claim 8 , wherein the third period is greater than the second period, and the first period is greater than the third period.
10 . The display device according to claim 9 , wherein the second sampling circuit generates the second sampling signal in response to a sampling control signal, and a pulse width of the sampling control signal is greater than a pulse width of the scan signal applied to the first scan line.
11 . The display device according to claim 10 , wherein the integrating circuit and the readout lines remain reset while scan signals are applied to at least two scan lines among the scan lines.
12 . The display device according to claim 1 , wherein the readout circuit samples the detection signals during the plurality of frame periods, and wherein with respect to a vertical synchronization signal defining a start of each of the frame periods, a time point at which the sampling is first performed is changed in each of the frame periods.
13 . The display device according to claim 1 , wherein the readout circuit samples the detection signals during the plurality of frame periods, and wherein with respect to a vertical synchronization signal defining a start of each of the frame periods, a time point at which the sampling is performed is identical in the frame periods, and a time point at which a first scan signal among the scan signals is applied is changed in each of the frame periods.
14 . The display device according to claim 1 , wherein the readout circuit receives the detection signals for less than all of the plurality of photo sensors during any one of the plurality of frame periods.
15 . The display device according to claim 1 , wherein each of the plurality of frame periods corresponds to a time in which only some of the plurality of photo sensors transmit a detection signal to the readout circuit.
16 . The display device according to claim 1 , wherein scan driver provides the scan signals only once to the plurality of photo sensors during each of the plurality of frame periods.
17 . The display device according to claim 1 , wherein each of the plurality of frame periods is an amount of time used to render a single still image in a sequence of images displayed on the display device.
18 . The display device according to claim 1 , wherein a detection signal is output from one of the plurality of photo sensors only when a control signal for the photo sensor is active simultaneous to the photo sensor being selected by one of the scan signals.
19 . The display device according to claim 18 , wherein a timing of the control signal varies between ones of the plurality of frame periods.
20 . An electronic device comprising: a processor configured to provide image data and a control signal; and a display device configured to display images based on the image data and the control signal, wherein the display device comprises: a plurality of pixels; a plurality of photo sensors; a scan driver configured to provide scan signals to the plurality of photo sensors and the plurality of pixels through scan lines; and a readout circuit configured to receive detection signals which are outputted from the plurality of photo sensors in response to the scan signals through readout lines, wherein the readout circuit receives the detection signals from all of the plurality of photo sensors during each of a plurality of frame periods, and in each frame period of the plurality of frame periods, the plurality of pixels receive data signals and some of the plurality of photo sensors output the detection signals.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application is a continuation of U.S. patent application Ser. No. 18/135,791 filed on Apr. 18, 2023 (now U.S. Pat. No. 12,106,601 issued Oct. 1, 2024), which claims priority under 35 U.S.C. § 119 to Korean patent application number 10-2022-0056715 filed on May 9, 2022, the disclosures of which are incorporated by reference herein in their entireties. TECHNICAL FIELD Various embodiments of the present disclosure relate to a display device. DESCRIPTION OF RELATED ART As information-oriented societies develop, applications for display devices continue to increase. For example, display devices have been applied to various electronic devices such as smartphones, digital cameras, notebook computers, navigation devices, and smart televisions. Biometric sensors for sensing fingerprints or the like have been integrated into a display panel of a display device. Research is being conducted on how to better incorporate these sensors into a display device. SUMMARY To reduce the production cost and prevent degradation in resolution, scan lines for scanning pixels and sensors in a display panel may be shared. However, due to an increase in surface area of the display panel and a high-frequency operation of the display device, the time it takes to scan each of the scan lines may be reduced, and the time (e.g., an individual readout time) it takes to read out a sensing signal from each of the sensors may be reduced. As a consequence, a sensing sensitivity of the sensors may be reduced. Various embodiments of the present disclosure are directed to a display device in which pixels and sensors may share scan lines, and to a display device in which a sufficient readout time can be secured. A display device in accordance with an embodiment of the present disclosure may include: scan lines including a first scan line and a second scan line which are adjacent to each other; pixels connected to the scan lines; photo sensors connected to at least some of the scan lines, the photo sensors including a first photo sensor connected to the first scan line and a readout line, and a second photo sensor connected to the second scan line and the readout line; a scan driver configured to provide scan signals to the scan lines; and a readout circuit configured to receive, through the readout line, detection signals which are outputted from the photo sensors in response to the scan signals, wherein, while the scan signals are provided to the first and second scan lines, the readout circuit samples a detection signal of one of the first photo sensor and the second photo sensor without sampling a detection signal of the other one of the first photo sensor and the second photo sensor. The readout circuit may receive the detection signals during a plurality of frame periods, and the readout circuit may receive a detection signal from the first photo sensor during a first frame period, and receives a detection signal from the second photo sensor during a second frame period. The scan lines may further include a third scan line and a fourth scan line, the photo sensors may further include a third photo sensor connected to the third scan line, and a fourth photo sensor connected to the fourth scan line, and the readout circuit may sample a detection signal of only one of the first, second, third, and fourth photo sensors while the scan signals are provided to the first, second, third, and fourth scan lines. The readout circuit may sample a detection signal of the first photo sensor during a first frame period, sample a detection signal of the second photo sensor during a second frame period, sample a detection signal of the third photo sensor during a third frame period, and sample a detection signal of the fourth photo sensor during a fourth frame period. The readout circuit may include: an integrating circuit configured to integrate a signal flowing through the readout line; a first sampling circuit configured to sample an output of the integrating circuit and generate a first sampling signal; a second sampling circuit configured to sample the output of the integrating circuit and generate a second sampling signal; and an analog-digital converter configured to output a digital value corresponding to a difference between the first sampling signal and the second sampling signal. During a first period in which a scan signal is applied to the first scan line, the integrating circuit and the readout line may be reset, in a second period between the first period and a third period in which a scan signal is applied to the second scan line, the first sampling circuit may generate the first sampling signal, and in the third period, the second sampling circuit may generate the second sampling signal. The third period may be greater than the second period, and the first period may be greater than the third period. The second sampling circuit may generate the second sampling signal in response to a sampling con