Pixel circuit and a driving method thereof, a display device

Patent metadata

Field	Value
Publication number	US-9978312-B2
Application number	US-201515122631-A
Country	US
Kind code	B2
Filing date	Jul 15, 2015
Priority date	Apr 28, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

The present invention provides a pixel circuit and a driving method thereof, a display device. The pixel circuit comprises a display driving module, a compensation module, a light emitting module and a fingerprint identification module. The compensation module is connected with the display driving module, a first signal terminal, a second signal terminal, a third signal terminal, a first voltage terminal, a data signal terminal and a common voltage terminal respectively. The display driving module is further connected with the light emitting module. The light emitting module is further connected with an enable signal terminal, the first voltage terminal and a second voltage terminal. The fingerprint identification module is connected with a fourth signal terminal, a fifth signal terminal and a readout signal line respectively.

First claim

The invention claimed is:

1. A method for driving a pixel circuit, the pixel circuit comprising a display driving sub-circuit, a compensation sub-circuit, a light emitting sub-circuit and a fingerprint identification sub-circuit;
the compensation sub-circuit, connected with the display driving sub-circuit, a first signal terminal, a second signal terminal, a third signal terminal, a first voltage terminal, a data signal terminal and a common voltage terminal respectively, for compensating the display driving sub-circuit for a threshold voltage through signals inputted by the first voltage terminal and the data signal terminal under the control of the first signal terminal, the second signal terminal, and the third signal terminal;
the display driving sub-circuit, further connected with the light emitting sub-circuit, for driving the light emitting sub-circuit to emit light after the display driving sub-circuit obtains the compensation for the threshold voltage;
the light emitting sub-circuit, further connected with an enable signal terminal, the first voltage terminal and the second voltage terminal, for emitting light through driving of the display driving sub-circuit under the control of the enable signal terminal, the first voltage terminal and the second voltage terminal;
the fingerprint identification sub-circuit, connected with a fourth signal terminal, a fifth signal terminal and a readout signal line respectively, for collecting fingerprint information under the control of the fourth signal terminal and the fifth signal terminal, and transmitting the collected fingerprint information to the readout signal line;
wherein the third signal terminal and the fifth signal terminal are connected with a third scanning signal line, the second signal terminal and the fourth signal terminal are connected with a second scanning signal line, and the first signal terminal is connected with a first scanning signal line; or,
the second signal terminal and the fifth signal terminal are connected with the second scanning signal line, the first signal terminal and the fourth signal terminal are connected with the first scanning signal line, and the third signal terminal is connected with the third scanning signal line,
the method comprising:
when a first signal terminal inputs a signal, resetting the display driving sub-circuit to remove a residual voltage;
when a second signal terminal inputs a signal, charging the compensation sub-circuit through a signal inputted by a common voltage terminal;
when a fourth signal terminal inputs a signal, resetting the fingerprint identification sub-circuit and collecting fingerprint information;
when a third signal terminal inputs a signal, keeping the compensation sub-circuit in a turn-on state, and compensating the display driving sub-circuit for a threshold voltage based on signals inputted by the first voltage terminal and the data signal terminal;
when a fifth signal terminal inputs a signal, transmitting the collected fingerprint information to a readout signal line by the fingerprint identification sub-circuit;
when an enable signal terminal inputs a signal, turning on the light emitting sub-circuit, and driving the light emitting sub-circuit to emit light by the display driving sub-circuit.

2. The method for driving a pixel circuit according to claim 1 , wherein when the third signal terminal and the fifth signal terminal are connected with the third scanning signal line, the second signal terminal and the fourth signal terminal are connected with the second scanning signal line, the method comprising:
at a first phase, the first scanning signal line inputs a signal to the first signal terminal to turn on the fifth transistor, a voltage of the first voltage terminal resets the gate of the driving transistor through the fifth transistor;
at a second phase, the second scanning signal line inputs a signal to the second signal terminal to turn on the fourth transistor, the sixth transistor and the seventh transistor, an input signal of the common voltage terminal charges the first capacitor; the first transistor, the second transistor, the third transistor, and the fifth transistor are cut off;
the second scanning signal line inputs a signal to the fourth signal terminal to turn on the eighth transistor, the second capacitor is discharged through the eighth transistor;
in the touch control process, a coupling capacitance is formed between a valley line of a fingerprint and the detection electrode, to enable the ninth transistor to be in a cut-off state; or, in the touch control process, a coupling capacitance is formed between a ridge line of a fingerprint and the detection electrode, to enable the ninth transistor to be in a turn-on state;
at a third phase, the third scanning signal line inputs a signal to the third signal terminal to turn on the third transistor, a signal inputted by the data voltage terminal is outputted to one terminal of the first capacitor, a voltage of the other terminal of the first capacitor jumps due to a bootstrap function of the first capacitor, so as to enable a gate voltage of the driving transistor to jump;
the third scanning signal line inputs a signal to the fifth signal terminal to turn on the tenth transistor, when the ninth transistor is in the cut-off state, an initial current signal of the second terminal of the ninth transistor is transmitted to the readout signal line through the tenth transistor; when the ninth transistor is in the turn-on state, the ninth transistor amplifies a signal inputted by the common voltage terminal, and transmits it to the readout signal line through the tenth transistor;
at a fourth phase, the enable signal terminal inputs a signal to turn on the first transistor and the second transistor, a current that flows through the first transistor, the driving transistor and the second transistor drives the light emitting device to emit light.

3. The method for driving a pixel circuit according to claim 1 , wherein when the second signal terminal and the fifth signal terminal are connected with the second scanning signal line, the first signal terminal and the fourth signal terminal are connected with the first scanning signal line, the method comprising:
at a first phase, the first scanning signal line inputs a signal to the first signal terminal to turn on the fifth transistor, a voltage of the first voltage terminal resets the gate of the driving transistor through the fifth transistor;
the first scanning signal line inputs a signal to the fourth signal terminal to turn on the eighth transistor, the second capacitor is reset through the eighth transistor;
at a second phase, the second scanning signal line inputs a signal to the second signal terminal to turn on the fourth transistor, the sixth transistor and the seventh transistor, an input signal of the first voltage terminal charges the first capacitor; the first transistor, the second transistor, the third transistor and the fifth transistor are cut off;
in the touch control process, a coupling capacitance is formed between a valley line of a fingerprint and the detection electrode, to enable the ninth transistor to be in a cut-off state; or, in the touch control process, a coupling capacitance is formed between a ridge line of a fingerprint and the detection electrode, to enable the ninth transistor to be in a turn-on state;
the second scanning signal line inputs a signal to the fifth signal terminal to turn on the tenth transistor, when the ninth transistor is in the cut-off state, an initial current signal of the second terminal of the ninth transistor is transmitted to the readout signal line through the tenth transistor; when the ninth transistor is in the turn-on state, the ninth transistor amplifies a signal inputted by the common voltage terminal, and transmits it to the readout signal line

Assignees

• Boe Technology Group Co Ltd
• Beijing Boe Optoelectronics Tech Co Ltd

Inventors

• Yang Shengji
• Dong Xue
• Wang Haisheng
• Liu Yingming
• Zhao Weijie
• Ding Xiaoliang

Classifications

• G06F3/04184 Primary

  Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally · CPC title

• G06F3/04166

  Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184) · 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

• G06K9/00013

  Physics · mapped topic

• G06F3/0416

  Control or interface arrangements specially adapted for digitisers · CPC title