Current detection device

Patent metadata

Field	Value
Publication number	US-12236883-B2
Application number	US-202118566530-A
Country	US
Kind code	B2
Filing date	Jun 25, 2021
Priority date	Jun 25, 2021
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A current detection device for detecting a current on the sense line, and compensating for a grayscale of a pixel in accordance with a difference in the detected currents, so as to provide the pixels with uniform brightness. An integration operation is performed on a sense line through an integration sub-circuitry to obtain an output voltage, and the current on the sense line is determined in accordance with the output voltage.

First claim

What is claimed is:

1. A current detection device, comprising a plurality of detection circuitries each coupled to a sense line in a display panel, wherein the detection circuitries comprise a current detection circuitry configured to detect a current on the sense line coupled to the current detection circuitry;
wherein the current detection circuitry comprises an integration sub-circuitry, a reference voltage write-in circuitry and a resetting circuitry;
one end of the reference voltage write-in circuitry is coupled to at least one sense line, another end of the reference voltage write-in circuitry is coupled to a reference voltage end, and the reference voltage write-in circuitry is configured to write a reference voltage into the at least one sense line; and
one end of the resetting circuitry is coupled to the at least one sense line, another end of the resetting circuitry is coupled to an initial voltage end and the integration sub-circuitry. and the resetting circuitry is configured to write an initial voltage into the at least one sense line;
wherein the reference voltage write-in circuitry comprises a reference level control switch, one end of the reference level control switch is coupled to the at least one sense line, and another end of the reference level control switch is coupled to the reference voltage end;
wherein the resetting circuitry comprises a follower amplifier and a resetting control switch;
one end of the follower amplifier is coupled to the resetting control switch, another end of the follower amplifier is coupled to the initial voltage end, and the follower amplifier is configured to reset a voltage on the sense line to the initial voltage when the resetting control switch is in an on state; and
one end of the resetting control switch is coupled to at least one sense line, and another end of the resetting control switch is coupled to the follower amplifier;
wherein the reference voltage end writes a reference voltage into a source electrode of a driving transistor through the reference level control switch, the sense line and a sensing control switch in a pixel circuitry.

2. The current detection device according to claim 1 , wherein the integration sub-circuitry is configured to perform an integration operation on the current on the sense line to obtain an integrated voltage signal, and sample the integrated voltage signal for multiple times to obtain an output voltage difference between different sampling points.

3. The current detection device according to claim 2 , wherein the integration sub-circuitry comprises an integrator, at least two voltage collection circuitries, a voltage difference determination circuitry and a digital-to-analogue conversion circuitry, wherein the integrator is configured to perform an integration operation on the current on the sense line to obtain an integrated voltage signal varying over time;
each voltage collection circuitry is configured to sample the integrated voltage signal and output a sampled voltage to the voltage difference determination circuitry, and the voltage collection circuitries sample the integrated voltage signal in sequence;
the voltage difference determination circuitry is configured to determine the output voltage difference in accordance with voltages collected by the voltage collection circuitries, and transmit the output voltage difference to the digital-to-analogue conversion circuitry; and
the digital-to-analogue conversion circuitry is configured to obtain the output voltage difference, convert the output voltage difference from an analogue signal to a digital signal, and output the digital signal to a controller, so that the controller determines the current on the sense line in accordance with the output voltage difference.

4. The current detection device according to claim 3 , wherein the voltage collection circuitry comprises a collection switch and a maintenance capacitor, one end of the collection switch is coupled to an output end of the integrator, another end of the collection switch is coupled to a first end of the maintenance capacitor and an input end of the voltage difference determination circuitry, the first end of the maintenance capacitor is coupled to the collection switch, and a second end of the maintenance capacitor is coupled to a ground end.

5. The current detection device according to claim 3 , wherein the voltage difference determination circuitry comprises a plurality of subtractors, each subtractor is coupled to two voltage collection circuitries, two input ends of each subtractor are coupled to the two voltage collection circuitries respectively, and an output end of the subtractor is coupled to the digital-to-analogue conversion circuitry.

6. The current detection device according to claim 5 , wherein the voltage difference determination circuitry further comprises a plurality of followers with a high input impedance, an input end of each subtractor is coupled to two followers, one end of the follower is coupled to the subtractor, and another end of the follower is coupled to the voltage collection circuitry;
wherein the voltage difference determination circuitry further comprises a first resistor module and a second resistor module;
one end of the first resistor module is coupled to a positive input end of the subtractor, and another end of the first resistor module is coupled to an output end of one follower; and
one end of the second resistor module is coupled to a negative input end of the subtractor, and another end of the second resistor module is coupled to an output end of the other follower;
wherein the first resistor module comprises a first resistor and a second resistor, one end of the first resistor is coupled to the output end of the follower, another end of the first resistor is coupled to the second resistor and the positive input end of the subtractor, and another end of the second resistor is coupled to a ground end; and
the second resistor module comprises a third resistor and a fourth resistor, one end of the third resistor is coupled to the output end of the follower, another end of the third resistor is coupled to the fourth resistor and the negative input end of the subtractor, and another end of the fourth resistor is coupled to the output end of the subtractor.

7. The current detection device according to claim 1 , wherein one end of the sense line is coupled to the current detection circuitry, and another end of the sense line is coupled to the sensing control switch in the pixel circuitry.

8. The current detection device according to claim 1 , wherein the current detection circuitry comprises an integration sub-circuitry, the integration sub-circuitry comprises an integrator, a digital-to-analogue conversion circuitry, a multiplexer and a plurality of voltage collection circuitries, and the plurality of voltage collection circuitries comprises at least two groups of voltage collection circuitries;
the integrator is configured to perform an integration operation on the current on the sense line to obtain an integrated voltage signal varying over time;
one group of voltage collection circuitries in the at least two groups of voltage collection circuitries are configured to sample the integrated voltage signal on the sense line for multiple times to obtain and store a plurality of sampling points, and the remaining groups of voltage collection circuitries in the at least two groups of voltage collection circuitries are configured to sample an integrated voltage signal on the other sense line for multiple times to obtain and store a plurality of sampling points when current detection is performed on the other sense line; and
the digital-to-analogue conversion circuitry is configured to perform analogue-to -digital

Assignees

• Boe Technology Group Co Ltd

Inventors

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

Classifications

• G09G2320/043

  Preventing or counteracting the effects of ageing · CPC title

• G09G2320/0233

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

• G09G2310/0297

  Special arrangements with multiplexing or demultiplexing of display data in the drivers for data electrodes, in a pre-processing circuitry delivering display data to said drivers or in the matrix panel, e.g. multiplexing plural data signals to one D/A converter or demultiplexing the D/A converter output to multiple columns · CPC title

• G09G2310/027

  Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters · CPC title

• G09G3/3233

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