Control method and control device for current detection apparatus

Patent metadata

Field	Value
Publication number	US-12548482-B2
Application number	US-202118573754-A
Country	US
Kind code	B2
Filing date	Jun 25, 2021
Priority date	Jun 25, 2021
Publication date	Feb 10, 2026
Grant date	Feb 10, 2026

Abstract

A control method and a control device for a current detection apparatus are provided, which are used to improve the accuracy of current detected by the current detection apparatus. A sensing control switch is controlled to be in an on state at a first time point before an integration operation is performed on the detection line; a current detection circuit is controlled to start the integration operation on a current of a detection line at the integration start time point to obtain an integrated voltage signal corresponding to the detection line; multiple samplings are performed on the integrated voltage signal, and an output voltage difference between different sampling points is determined; and the current of the detection line is determined based on the output voltage difference.

First claim

What is claimed is:

1 . A control method for a current detection apparatus, wherein the apparatus comprises: a plurality of detection circuits, wherein each of the detection circuits is coupled to a detection line in a display panel; the detection line is coupled to a sensing control switch in a pixel circuit, and the method comprises:
controlling the sensing control switch to be in an on state at a first time point before each of the detection circuits performs an integration operation on the detection line; a duration between the first time point and an integration start time point at which each of the detection circuits starts the integration operation being a first duration; controlling each of the detection circuits to start the integration operation on a current of the detection line at the integration start time point to obtain an integrated voltage signal corresponding to the detection line; performing multiple samplings on the integrated voltage signal, and determining an output voltage difference between different sampling points; and determining the current of the detection line based on the output voltage difference; wherein an integration sub-circuit comprises a voltage acquisition circuit and a voltage difference determination circuit, and the performing multiple samplings on the integrated voltage signal, and determining an output voltage difference between different sampling points, comprises:
controlling the voltage acquisition circuit to acquire a first integrated voltage of the integrated voltage signal at a first integrated time point;
controlling the voltage acquisition circuit to acquire a second integrated voltage of the integrated voltage signal at a second integrated time point; and
controlling the voltage difference determination circuit to determine a difference between the first integrated voltage and the second integrated voltage as the output voltage difference.

2 . The method according to claim 1 , wherein a duration between a time point when the integrated voltage signal is sampled for the first time and the integration start time point is a second duration, and the second duration is greater than or equal to a duration for establishing balance, wherein the duration for establishing balance is a duration required for the sensing control switch and each of the detection circuits to establish stable balance with the detection line.

3 . The method according to claim 1 , wherein the integration sub-circuit is comprised in each of the detection circuits, the integration sub-circuit is configured to perform the integration operation, and before the controlling each of the detection circuits to start the integration operation on a current of the detection line at the integration start time point, the method further comprises:
performing a reset operation on the detection line and the integration sub-circuit.

4 . The method according to claim 3 , wherein before the performing a reset operation on the detection line and the integration sub-circuit, the method further comprises:
writing a grayscale voltage to a gate electrode of a drive transistor of the pixel circuit; and writing a reference voltage to a source electrode of the drive transistor and the detection line.

5 . The method according to claim 3 , wherein an integrator is provided in the integration sub-circuit, a second end of the integrator is coupled to the detection line, a first end of the integrator is coupled to an initial voltage end, and the first end of the integrator is coupled to the detection line via a reset circuit, the reset circuit comprises a reset control switch and a follower amplifier, one end of the follower amplifier is coupled to the first end of the integrator, and the other end is coupled to the reset control switch; and
the performing a reset operation on the detection line, comprises: turning on the reset control switch to reset a potential of the detection line and a potential of a source electrode of a drive transistor in the pixel circuit to initial voltages.

6 . The method according to claim 3 , wherein the integration sub-circuit is provided with an integrator, and the integrator comprises a low noise operational amplifier, an integrating capacitor and an integrating control switch which are arranged in parallel, wherein one end of the integrating capacitor and the integrating control switch is coupled to a second end of the low noise operational amplifier, and the other end is coupled to a third end of the low noise operational amplifier, and a first end of the low noise operational amplifier is coupled to an initial voltage end; and
the performing a reset operation on the integration sub-circuit, comprises: turning on the integrating control switch to clear charges in the integrating capacitor.

7 . The method according to claim 3 , wherein if each of the detection circuits is coupled to a plurality of detection lines, grayscale voltages are written to pixel circuits respectively corresponding to the plurality of detection lines at a same time; and
after completing the writing of the grayscale voltages, simultaneously performing the reset operation on the plurality of detection lines.

8 . The method according to claim 7 , wherein each detection line is coupled to a multiplexing control switch; one end of the multiplexing control switch is coupled to the detection line, and the other end is coupled to the detection circuit corresponding to the detection line; and
after the determining the current of the detection line based on the output voltage difference, the method further comprises: setting the multiplexing control switch to which the detection line is coupled to an off state, and turning on the multiplexing control switch of a next detection line to detect a current of the next detection line through the detection circuit.

9 . The method according to claim 1 , wherein the performing multiple samplings on the integrated voltage signal, and determining an output voltage difference between different sampling points, comprises:
forming a sampling point pair from two adjacent sampling points, and determining a voltage difference between the two sampling points in each sampling point pair; and determining an average of the voltage differences of different sampling point pairs as the output voltage difference.

10 . The method according to claim 1 , wherein after the determining the current of the detection line based on the output voltage difference, the method further comprises:
if the current of the detection line is less than a preset value, then acquiring a compensation current of the detection line; and performing a correction operation on the current of the detection line based on the compensation current.

11 . The method according to claim 10 , wherein the acquiring a compensation current of the detection line, comprises:
writing a drive voltage to a drive transistor in the pixel circuit; wherein a voltage difference between a gate electrode and a source electrode of the drive transistor of the drive voltage needs to be less than a threshold voltage of the drive transistor; and detecting a current of the detection line by the detection circuit corresponding to the detection line as the compensation current.

12 . The method according to claim 2 , wherein the first duration is a duration of a capacitance balance phase required for a parasitic load capacitor to establish a stable balance with the pixel circuit and the sensing control switch;
the parasitic load capacitor is a capacitor created between the detection line and crossing lines of different layers.

13 . The method according to

Assignees

• Boe Technology Group Co Ltd

Inventors

• Yin Xinshe
• Yang Hualing
• Han Xinbin
• Shang Guangliang
• Zhu Jianchao

Classifications

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G09G2300/0842

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

• G09G2300/0819

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

• G09G3/3233

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G01R19/2509 Primary

  Details concerning sampling, digitizing or waveform capturing · CPC title