Sensing circuit, display device including sensing circuit, and method of driving sensing circuit

Patent metadata

Field	Value
Publication number	US-12260818-B2
Application number	US-202318195684-A
Country	US
Kind code	B2
Filing date	May 10, 2023
Priority date	Jul 27, 2022
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A sensing circuit includes a first line selection switch which connects a first sensing line to a sensing channel in a first sub-sensing period, a first noise selection switch which connects the first sensing line to a reference channel in a second sub-sensing period, a second line selection switch which connects a second sensing line to the sensing channel in the second sub-sensing period, and a second noise selection switch which connects the second sensing line to the reference channel in the first sub-sensing period. The sensing channel samples a first sensing voltage and noise of the first sensing line and the reference channel samples noise of the second sensing line in a first sampling period, and the sensing channel samples a second sensing voltage and noise of the second sensing line and the reference channel samples noise of the first sensing line in a second sampling period.

First claim

What is claimed is:

1. A sensing circuit of a display device, comprising:
a first line selection switch which connects a first sensing line to a sensing channel in a first sub-sensing period in a first sensing period;
a first noise selection switch which connects the first sensing line to a reference channel in a second sub-sensing period in a second sensing period;
a second line selection switch which connects a second sensing line to the sensing channel in the second sub-sensing period; and
a second noise selection switch which connects the second sensing line to the reference channel in the first sub-sensing period,
wherein, in a first sampling period in the first sub-sensing period, the sensing channel samples a first sensing voltage and a noise of the first sensing line, and the reference channel samples a noise of the second sensing line,
wherein, in a second sampling period in the second sub-sensing period, the sensing channel samples a second sensing voltage and a noise of the second sensing line, and the reference channel samples a noise of the first sensing line, and
wherein the first sensing line and the second sensing line are connected to different pixels, each including a first switching transistor connected to a data line and a second switching transistor connected to a corresponding one of the first sensing line and the second sensing line.

2. The sensing circuit of claim 1 , wherein the first sensing line and the second sensing line are connected to a first pixel and a second pixel, respectively,
wherein the first switching transistor of each of the first and second pixels is turned-on in response to a scan signal and the second switching transistor of each of the first and second pixels is turned-on in response to a sensing signal,
wherein, in the first sampling period, each of the first and second switching transistors included in the first pixel is turned-on, the first switching transistor included in the second pixel is turned-off, and the second switching transistor included in the second pixel is turned-on, and
wherein, in the second sampling period, the first switching transistor included in the first pixel is turned-off, the second switching transistor included in the first pixel is turned-on, and each of the first and second switching transistors included in the second pixel is turned-on.

3. The sensing circuit of claim 1 , further comprising:
a sensing line initialization circuit which simultaneously initializes the first sensing line and the second sensing line in the first sub-sensing period and the second sub-sensing period.

4. The sensing circuit of claim 3 , wherein the sensing line initialization circuit includes:
a first sensing line initialization switch which applies an initialization voltage to the first sensing line in response to a sensing line initialization signal; and
a second sensing line initialization switch which applies the initialization voltage to the second sensing line in response to the sensing line initialization signal.

5. The sensing circuit of claim 4 , wherein the sensing channel includes:
a sampling capacitor including a first electrode and a second electrode;
a first sampling switch which connects the first and second line selection switches to the first electrode of the sampling capacitor in response to a sampling signal; and
a first reference switch which applies a reference voltage to the second electrode of the sampling capacitor in response to a reference signal.

6. The sensing circuit of claim 5 , wherein the reference channel includes:
a reference capacitor including a first electrode and a second electrode;
an initialization switch which provides the initialization voltage to a first node in response to an initialization signal;
a second sampling switch which connects the first node to the first electrode of the reference capacitor and applies the initialization voltage to the first electrode of the reference capacitor in response to the sampling signal; and
a second reference switch which applies the reference voltage to the second electrode of the reference capacitor in response to the reference signal.

7. The sensing circuit of claim 6 , further comprising:
a channel connection switch which connects the sensing channel to the reference channel,
wherein the channel connection switch connects the first electrode of the sampling capacitor to the first electrode of the reference capacitor in response to a channel connection signal.

8. The sensing circuit of claim 7 , further comprising:
an analog-to-digital converter; and
a switch matrix which connects the sensing channel and the reference channel to the analog-to-digital converter.

9. The sensing circuit of claim 8 , wherein the first sensing period includes:
the first sub-sensing period in which a sensing operation on a first pixel connected to the first sensing line is performed by the sensing channel and a sensing operation on a second pixel connected to the second sensing line is performed by the reference channel; and
a first data output period in which first sensing data corresponding to the first sensing voltage is output, and
wherein the second sensing period includes:
the second sub-sensing period in which a sensing operation on the second pixel connected to the second sensing line is performed by the sensing channel and a sensing operation on the first pixel connected to the first sensing line is performed by the reference channel; and
a second data output period in which second sensing data corresponding to the second sensing voltage is output.

10. The sensing circuit of claim 9 , wherein the first sub-sensing period includes:
a first sensing line initialization period in which the first sensing line and the second sensing line are simultaneously initialized;
a first capacitor initialization period in which the sampling capacitor and the reference capacitor are initialized;
the first sampling period in which a first sensing voltage and a noise of the first sensing line and a noise of the second sensing line are sampled; and
a first analog-to-digital conversion period in which the first sensing voltage of the first sensing line is converted to the first sensing data by offsetting the noise of the first sensing line and the noise of the second sensing line, and
wherein the second sub-sensing period includes:
a second sensing line initialization period in which the first sensing line and the second sensing line are simultaneously initialized;
a second capacitor initialization period in which the sampling capacitor and the reference capacitor are initialized;
the second sampling period in which a second sensing voltage and a noise of the second sensing line and a noise of the first sensing line are sampled; and
a second analog-to-digital conversion period in which the second sensing voltage of the second sensing line is converted to the second sensing data by offsetting the noise of the second sensing line and the noise of the first sensing line.

11. The sensing circuit of claim 10 , wherein the sensing line initialization signal has an activation level in the first and second sensing line initialization periods, and
wherein the sensing line initialization circuit applies the initialization voltage to the first sensing line and the second sensing line in response to the sensing line initialization signal having the activation level.

12. The sensing circuit of claim 10 , wherein each of the sampling signal, the reference signal, the initialization signal, and the channel connection signal has an activation level in the first and second capacitor initialization periods,
wherein the initialization sw

Assignees

• Samsung Display Co Ltd

Inventors

• Jung Hayong
• Lee Wook
• Kim Sung Hwan
• Shin Jaehoon

Classifications

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title

• G09G2330/12

  Test circuits or failure detection circuits included in a display system, as permanent part thereof · CPC title

• G09G2320/029

  by monitoring one or more pixels in the display panel, e.g. by monitoring a fixed reference pixel · CPC title

• G09G2300/0842

  forming a memory circuit, e.g. a dynamic memory with one capacitor · CPC title