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US 12,217,693 B2Granted
Pixel driving circuit and display panel
AssigneeTcl China Star Optoelectronics Technology Co., Ltd.
InventorXiaolong Chen
Life of this patent
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Abstract
A pixel driving circuit and a display panel are provided by the present application. An electrical potential of a control terminal of a driving module can be kept stable through a detection module by connecting the detection module with a control terminal of the driving module when detecting a threshold voltage of the driving module. In this way, an obtained threshold voltage of the driving module is accurate, to make the threshold voltage of the driving module can be accurately compensated, and a display uniformity and a stability of the display panel are improved.
Claims15
A pixel driving circuit, comprising:
- a driving module, a data writing module, an initialization module, a first capacitor, a detection module and a compensation module;
- wherein a control terminal of the driving module is connected to a first node, and wherein an input terminal of the driving module is connected to a constant voltage terminal of high electrical potential, and wherein an output terminal is connected to a second node, the driving module comprises a first thin film transistor;
- wherein a control terminal of the data writing module is connected to a first scan signal line, and wherein an input terminal of the data writing module is connected to a data signal line, and wherein an output terminal of the data writing module is connected to the first node;
- wherein a control terminal of the initialization module is connected to a second scan signal line, and wherein an input terminal of the initialization module is connected to a reset signal line, and wherein an output terminal of the initialization module is connected to the second node;
- wherein a first terminal of the first capacitor is connected to the first node, and wherein a second terminal of the first capacitor is connected to the second node;
- and
- wherein the detection module comprises an operational amplifier, a first switch, a second switch, and a second capacitor, the detection module is connected to the first node and is configured to control an electrical potential of the first node to obtain a threshold voltage of the driving module, wherein a first input terminal of the operational amplifier is connected to the first node through the first switch, and wherein a second input terminal of the operational amplifier is connected to a reference signal line, wherein the first switch is coupled between the first node and the first input terminal of the operational amplifier;
- and wherein the second switch and the second capacitor are coupled between the first input terminal of the operational amplifier and an output terminal of the operational amplifier;
- wherein the compensation module comprises an analog-to-digital converter, a control device, a digital-to-analog converter, and a third switch, an input terminal of the analog-to-digital converter is connected to the output terminal of the operational amplifier, the analog-to-digital converter is connected to the digital-to-analog converter through the control device, the control device is configured to superimpose a compensation voltage to a data signal from the data signal line, an output terminal of the digital-to-analog converter is connected to an input terminal of the data writing module through the third switch,
- wherein the third switch is configured to be turned on when the first switch and the second switch are turned off, such that an electrical potential difference between the first node and the second node is a sum of an electrical potential of the data signal and the threshold voltage, and the first thin film transistor is turned on,
- wherein the third switch is configured to be turned on when the first switch and the second switch are turned off, such that a current flowing through the first thin film transistor is not a function of the threshold voltage and is a function of only the data signal.
8 more elements
A display panel, further comprising an organic light emitting diode and a pixel driving circuit, the pixel driving circuit comprising:
- a driving module, a data writing module, an initialization module, a first capacitor, a detection module and a compensation module;
- wherein a control terminal of the driving module is connected to a first node, and wherein an input terminal of the driving module is connected to a constant voltage terminal of high electrical potential, and wherein an output terminal is connected to a second node, the driving module comprises a first thin film transistor;
- wherein a control terminal of the data writing module is connected to a first scan signal line, and wherein an input terminal of the data writing module is connected to a data signal line, and wherein an output terminal of the data writing module is connected to the first node;
- wherein a control terminal of the initialization module is connected to a second scan signal line, and wherein an input terminal of the initialization module is connected to a reset signal line, and wherein an output terminal of the initialization module is connected to the second node;
- wherein a first terminal of the first capacitor is connected to the first node, and wherein a second terminal of the first capacitor is connected to the second node;
- and
- wherein the detection module comprises an operational amplifier, a first switch, a second switch, and a second capacitor, the detection module is connected to the first node and is configured to control an electrical potential of the first node to obtain a threshold voltage of the driving module, wherein a first input terminal of the operational amplifier is connected to the first node through the first switch, and wherein a second input terminal of the operational amplifier is connected to a reference signal line, wherein the first switch is coupled between the first node and the first input terminal of the operational amplifier;
- and wherein the second switch and the second capacitor are coupled between the first input terminal of the operational amplifier and an output terminal of the operational amplifier;
- wherein the compensation module comprises an analog-to-digital converter, a control device, a digital-to-analog converter, and a third switch, an input terminal of the analog-to-digital converter is connected to the output terminal of the operational amplifier, the analog-to-digital converter is connected to the digital-to-analog converter through the control device, the control device is configured to superimpose a compensation voltage to a data signal from the data signal line, an output terminal of the digital-to-analog converter is connected to an input terminal of the data writing module through the third switch,
- wherein the third switch is configured to be turned on when the first switch and the second switch are turned off, such that an electrical potential difference between the first node and the second node is a sum of an electrical potential of the data signal and the threshold voltage, and the first thin film transistor is turned on,
- wherein the third switch is configured to be turned on when the first switch and the second switch are turned off, such that a current flowing through the first thin film transistor is not a function of the threshold voltage and is a function of only the data signal;
- wherein the organic light emitting diode is coupled between the output terminal of the driving module of the pixel driving circuit and the constant voltage terminal of low electrical potential, to make the pixel driving circuit configured to drive the organic light emitting diode to emit light.
9 more elements
Dependencies are inferred from the claim text.