CN203366705U - Pixel circuit, organic electroluminescence display panel and display device - Google Patents

Pixel circuit, organic electroluminescence display panel and display device Download PDF

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Publication number
CN203366705U
CN203366705U CN2013204650584U CN201320465058U CN203366705U CN 203366705 U CN203366705 U CN 203366705U CN 2013204650584 U CN2013204650584 U CN 2013204650584U CN 201320465058 U CN201320465058 U CN 201320465058U CN 203366705 U CN203366705 U CN 203366705U
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submodule
voltage
transistor
switching transistor
signal
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周全国
祁小敬
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BOE Technology Group Co Ltd
Chengdu BOE Optoelectronics Technology Co Ltd
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BOE Technology Group Co Ltd
Chengdu BOE Optoelectronics Technology Co Ltd
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Abstract

The utility model discloses a pixel circuit, an organic electroluminescence display panel and a display device. The pixel circuit comprises a drive submodule, a data write-in submodule, a touch control detection submodule with a light-sensitive device and a luminescence control submodule with a luminescent device. Under the control of a reset signal terminal, a scanning signal terminal and a data signal terminal, the data write-in submodule transmits a data signal to a first terminal of the drive submodule. Under the control of a touch control signal terminal, the touch control detection submodule controls the drive submodule to output a touch control detection signal, and the touch control detection signal is decreasing with the increasing of intensity of lights irradiated on the light-sensitive device so as to realize the touch control function. Under the control of a luminescence control signal terminal, the luminescence control submodule controls the drive submodule to drive the luminescent device to shine so as to realize the display function. Touch control and display functions are integrated to the pixel circuit. Thus, manufacturing costs for respectively arranging a display drive circuit and a touch control circuit can be saved.

Description

Pixel circuit, organic electroluminescent display panel and display device
Technical Field
The utility model relates to a show technical field, especially relate to a pixel circuit, organic electroluminescent display panel and display device.
Background
With the development of light, thin, high resolution, intelligent, and energy saving display devices, Touch Screen panels (Touch screens) are increasingly used. At present, an embedded touch screen (In Cell touch panel) can reduce the overall thickness of a module by embedding a touch part inside a display screen, and can greatly reduce the manufacturing cost of the touch screen, so that the touch screen is favored by large panel manufacturers. An Organic Light Emitting Diode (OLED) display panel has attracted attention because of its advantages of low power consumption, high brightness, low cost, wide viewing angle, and fast response speed.
In the existing embedded touch screen OLED display panel, generally, circuits for implementing display driving and touch driving are designed respectively, that is, one set of circuit is used for implementing a touch function, the other set of circuit is used for implementing the display driving function of the OLED, and the display driving circuit and the touch circuit are respectively arranged, so that the defects of high manufacturing cost, heavy display screen and thick display screen exist.
SUMMERY OF THE UTILITY MODEL
The embodiment of the utility model provides a pixel circuit, organic electroluminescent display panel and display device for realize the pixel circuit of integrated touch-control and display function.
An embodiment of the utility model provides a pixel circuit, include: the drive submodule, the data write-in submodule, the touch control detection submodule with a photosensitive device and the light-emitting control submodule with a light-emitting device; wherein,
the first end of the driving sub-module is respectively connected with the first end of the data writing sub-module and the first end of the touch detection sub-module, the second end of the driving sub-module is respectively connected with the second end of the data writing sub-module, the second end of the touch detection sub-module and the first reference signal end, and the third end of the driving sub-module is respectively connected with the third end of the data writing sub-module, the third end of the touch detection sub-module and the first end of the light-emitting control sub-module;
the fourth end of the data writing submodule is connected with a reset signal end, the fifth end of the data writing submodule is connected with a scanning signal end, and the sixth end of the data writing submodule is connected with a data signal end; under the control of the reset signal terminal, the scanning signal terminal and the data signal terminal, the data writing submodule transmits a data signal to the first terminal of the driving submodule;
the fourth end of the touch detection submodule is connected with a touch control signal end, and the fifth end of the touch detection submodule is connected with a touch signal reading end; under the control of the touch control signal end, the touch detection submodule controls the driving submodule to output a touch detection signal to the touch signal reading end, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device;
the second end of the light-emitting control sub-module is connected with a second reference signal end, and the third end of the light-emitting control sub-module is connected with a light-emitting control signal end; and under the control of the light-emitting control signal end, the light-emitting control submodule controls the driving submodule to drive the light-emitting device to emit light.
The embodiment of the utility model provides a pixel circuit, this pixel circuit is under the control of reset signal end, scanning signal end and data signal end, and data write-in submodule transmits data signal to the first end of drive submodule; under the control of a touch control signal end, the touch detection submodule controls the driving submodule to output a touch detection signal to the touch signal reading end, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device, so that the touch detection function is realized; under the control of the light-emitting control signal end, the light-emitting control submodule controls the driving submodule to drive the light-emitting device to emit light, and the display driving function is realized. The pixel circuit integrates touch control and display functions, so that the manufacturing cost for respectively arranging the display driving circuit and the touch control circuit can be saved, and the thickness of the display panel can be reduced.
Preferably, in order to facilitate implementation, in the pixel circuit provided in the embodiment of the present invention, the first terminal and the second terminal of the driving sub-module are signal input terminals, and the third terminal of the driving sub-module is a signal output terminal;
the first end of the data writing sub-module is a signal output end, and the second end, the third end, the fourth end, the fifth end and the sixth end of the data writing sub-module are signal input ends;
the first end of the touch detection submodule is a signal input end, and the second end of the touch detection submodule is a signal output end, or the first end of the touch detection submodule is a signal output end, and the second end of the touch detection submodule is a signal input end; the third end and the fourth end of the touch detection sub-module are signal input ends, and the fifth end of the touch detection sub-module is a signal output end;
the first end of the light-emitting control sub-module is a signal input end, and the second end of the light-emitting control sub-module is a signal output end, or the first end of the light-emitting control sub-module is a signal output end, and the second end of the light-emitting control sub-module is a signal input end; and the third end of the light-emitting control submodule is a signal input end.
Preferably, in order to facilitate implementation, in the pixel circuit provided in an embodiment of the present invention, the driving sub-module specifically includes: a drive transistor; wherein,
the grid electrode of the driving transistor is the first end of the driving submodule, the source electrode of the driving transistor is the second end of the driving submodule, and the drain electrode of the driving transistor is the third end of the driving submodule.
Preferably, in order to ensure that the driving transistor can work normally, when the driving transistor is an N-type transistor, the voltage of the first reference signal terminal is a negative voltage or a zero voltage, and the voltage of the second reference signal terminal is a positive voltage; when the driving transistor is a P-type transistor, the voltage of the first reference signal end is a positive voltage, and the voltage of the second reference signal end is a negative voltage or zero voltage.
Preferably, in order to facilitate implementation, in the pixel circuit provided in the embodiment of the present invention, the data writing sub-module specifically includes: a first switching transistor, a second switching transistor, a first capacitor and a second capacitor; wherein,
the grid electrode of the first switch transistor is connected with the reset signal end, the source electrode of the first switch transistor is connected with the third end of the driving submodule, and the drain electrode of the first switch transistor is respectively connected with the first end of the driving submodule, the first end of the first capacitor and the first end of the second capacitor;
the grid electrode of the second switch transistor is connected with the scanning signal end, the source electrode of the second switch transistor is connected with the data signal end, and the drain electrode of the second switch transistor is connected with the second end of the first capacitor;
and the second end of the second capacitor is respectively connected with the first reference signal end, the second end of the driving submodule and the second end of the touch detection submodule.
Specifically, in practical implementation, in the pixel circuit provided in an embodiment of the present invention, the first switch transistor is an N-type transistor or a P-type transistor; and/or the second switch transistor is an N-type transistor or a P-type transistor.
Preferably, in order to facilitate the implementation, in the pixel circuit provided in the embodiment of the present invention, the touch detection sub-module further includes: a third switching transistor and a fourth switching transistor; wherein,
the grid electrode of the third switching transistor is connected with the touch control signal end, and the drain electrode of the third switching transistor is connected with the first end of the photosensitive device;
the source electrode of the third switching transistor is connected with the first end of the driving submodule, and the second end of the photosensitive device is connected with the first reference signal end; or, the source of the third switching transistor is connected with the first reference signal end, and the second end of the photosensitive device is connected with the first end of the driving submodule;
the grid electrode of the fourth switching transistor is connected with the touch control signal end, the source electrode of the fourth switching transistor is connected with the third end of the driving submodule, and the drain electrode of the fourth switching transistor is connected with the touch signal reading end.
Specifically, in this embodiment, in the pixel circuit provided in the present invention, the third switching transistor and the fourth switching transistor are N-type transistors; or, the third switching transistor and the fourth switching transistor are P-type transistors.
Preferably, for convenience of implementation, in the pixel circuit provided in the embodiment of the present invention, the light-emitting control sub-module further includes: a fifth switching transistor; wherein,
the grid electrode of the fifth switching transistor is connected with the light-emitting control signal end, and the drain electrode of the fifth switching transistor is connected with the first end of the light-emitting device;
the source electrode of the fifth switching transistor is connected with the third end of the driving submodule, and the second end of the light-emitting device is connected with the second reference signal end; or, the source of the fifth switching transistor is connected to the second reference signal terminal; and the second end of the light-emitting device is connected with the third end of the driving sub-module.
In particular, in this embodiment, in the pixel circuit provided in the present invention, the fifth switching transistor is an N-type transistor or a P-type transistor.
The embodiment of the utility model provides an organic electroluminescent display panel, include the embodiment of the utility model provides a pixel circuit.
The embodiment of the utility model provides a display device, include the embodiment of the utility model provides an organic electroluminescent display panel.
Drawings
Fig. 1 is a schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 2a is a schematic diagram of a specific structure of a pixel circuit according to an embodiment of the present invention;
fig. 2b is a second schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 2c is one of circuit timing diagrams of a pixel circuit according to an embodiment of the present invention;
fig. 3a is a third schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 3b is a fourth schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 3c is a second circuit timing diagram of the pixel circuit according to the embodiment of the present invention;
fig. 4a is a fifth schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 4b is a sixth schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 4c is a third circuit timing diagram of the pixel circuit according to the embodiment of the present invention;
fig. 5a is a seventh schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 5b is an eighth schematic structural diagram of a pixel circuit according to an embodiment of the present invention;
fig. 5c is a fourth circuit timing diagram of the pixel circuit according to the embodiment of the present invention.
Detailed Description
Embodiments of a pixel circuit, an organic electroluminescent display panel, and a display device according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
An embodiment of the present invention provides a pixel circuit, as shown in fig. 1, include: a driving sub-module 1, a data writing sub-module 2, a touch sensing sub-module 3 having a photosensor, and a light emission control sub-module 4 having a light emitting device (the photosensor and the light emitting device are not shown in fig. 1); wherein,
a first end 1a of the driving submodule 1 is respectively connected with a first end 2a of the data writing submodule 2 and a first end 3a of the touch sensing submodule 3, a second end 1b of the driving submodule 1 is respectively connected with a second end 2b of the data writing submodule 2, a second end 3b of the touch sensing submodule 3 and a first reference signal terminal Ref1, and a third end 1c of the driving submodule 1 is respectively connected with a third end 2c of the data writing submodule 2, a third end 3c of the touch sensing submodule 3 and a first end 4a of the light-emitting control submodule 4;
the fourth end 2d of the Data writing sub-module 2 is connected with a Reset signal end Reset, the fifth end 2e of the Data writing sub-module 2 is connected with a scanning signal end Scan, and the sixth end 2f of the Data writing sub-module 2 is connected with a Data signal end Data; under the control of the Reset signal terminal Reset, the Scan signal terminal Scan and the Data signal terminal Data, the Data writing submodule 2 transmits a Data signal to the first terminal 1a of the driving submodule 1 by the Data writing submodule 2;
the fourth end 3d of the touch detection sub-module 3 is connected with the touch control signal end Select, and the fifth end 3e of the touch detection sub-module 3 is connected with the touch signal reading end Sensor; under the control of the touch control signal terminal Select, the touch detection submodule 3 controls the driving submodule 1 to output a touch detection signal to the touch signal reading terminal Sensor, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device;
the second end 4b of the light-emitting control sub-module 4 is connected with a second reference signal terminal Ref2, and the third end 4c of the light-emitting control sub-module 4 is connected with a light-emitting control signal terminal EM; under the control of the light-emitting control signal terminal EM, the light-emitting control sub-module 4 controls the driving sub-module 1 to drive the light-emitting device to emit light.
The embodiment of the utility model provides an above-mentioned pixel circuit, under the control of Reset signal end Reset, scanning signal end Scan and Data signal end Data, Data write in submodule 2 and transmit Data signal to drive submodule 1's first end 1 a; under the control of the touch control signal terminal Select, the touch detection submodule 3 controls the driving submodule 1 to output a touch detection signal to the touch signal reading terminal Sensor, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device, so that the touch detection function is realized; under the control of the light-emitting control signal end EM, the light-emitting control submodule 4 controls the driving submodule 1 to drive the light-emitting device to emit light, and the display driving function is achieved. The pixel circuit integrates touch control and display functions, so that the manufacturing cost for respectively arranging the display driving circuit and the touch control circuit can be saved, and the thickness of the display panel can be reduced.
Specifically, in the specific implementation, in the pixel circuit provided in the embodiment of the present invention, the first end 1a and the second end 1b of the driving sub-module 1 are signal input ends, and the third end 1c of the driving sub-module 1 is a signal output end;
the first end 2a of the data writing sub-module 2 is a signal output end, and the second end 2b, the third end 2c, the fourth end 2d, the fifth end 2e and the sixth end 2f of the data writing sub-module 2 are signal input ends;
the first end 3a of the touch detection submodule 3 is a signal input end, and the second end 3b is a signal output end, or the first end 3a of the touch detection submodule 3 is a signal output end, and the second end 3b is a signal input end; the third end 3c and the fourth end 3d of the touch detection sub-module 3 are signal input ends, and the fifth end 3e of the touch detection sub-module 3 is a signal output end;
the first end 4a of the light-emitting control sub-module 4 is a signal input end, and the second end 4b is a signal output end, or the first end 4a of the light-emitting control sub-module 4 is a signal output end, and the second end 4b is a signal input end; the third terminal 4c of the lighting control sub-module 4 is a signal input terminal.
Specifically, in the pixel circuit provided by the embodiment of the present invention, the signal of the first reference signal terminal Ref1 is generally a dc signal, that is, the first reference signal terminal Ref1 is connected to a dc signal source; the signal of the second reference signal terminal Ref2 is also a dc signal, i.e. the second reference signal terminal Ref2 is connected to a dc signal source.
In specific implementation, the driving control sub-module 1 in the pixel circuit provided in the embodiment of the present invention, as shown in fig. 1, may specifically include: a driving transistor T0; wherein,
the gate of the driving transistor T0 is the first terminal 1a of the driving submodule 1, the source of the driving transistor T0 is the second terminal 1b of the driving submodule 1, and the drain of the driving transistor T0 is the third terminal 1c of the driving submodule 1. Of course, the driving submodule 1 may also have another structure capable of implementing the driving control function thereof, and is not limited herein.
In a specific implementation, the driving transistor T0 may be an N-type transistor or a P-type transistor, and is not limited herein. In order to ensure the normal operation of the driving transistor T0, when the driving transistor T0 is an N-type transistor, the threshold voltage V is setthThe voltage of the first reference signal terminal Ref1 is a negative voltage or a zero voltage, and the voltage of the second reference signal terminal Ref2 is a positive voltage; when the driving transistor T0 is a P-type transistor, its threshold voltage VthThe voltage of the first reference signal terminal Ref1 is a positive voltage, and the voltage of the second reference signal terminal Ref2 is a negative voltage or zero voltage.
Specifically, the embodiment of the present invention provides a working of the pixel circuit divided into two stages, i.e., a touch stage and a display stage. The pixel circuit can execute the work of a touch control stage firstly and then execute the work of a display stage when in work; the display stage may be executed first, and then the touch stage may be executed, which is not limited herein.
The working principle of the pixel circuit provided by the embodiments of the present invention in the touch stage and the display stage is briefly introduced below.
In the touch stage, the operation of the pixel circuit is divided into three stages:
the first stage is as follows: an initialization phase in which the pixel circuit effects initialization of the data writing sub-module 2. At this stage, the touch detection submodule 3 and the light emission control submodule 4 are in an off state, and the Data write submodule 2 is Reset under the control of the Reset signal terminal Reset, the Scan signal terminal Scan, and the Data signal terminal Data, so that the first terminal 2a of the Data write submodule 2 inputs an initial voltage value to the gate of the driving transistor T0.
And a second stage: and a data writing stage in which the pixel circuit implements data writing to the gate of the driving transistor T0. At this stage, the touch detection submodule 3 and the light-emitting control submodule 4 are in an off state, the data writing submodule 2 is in an on state under the control of the scanning signal terminal Scan, and the data writing submodule 2 transmits a data signal to the first terminal 1a of the driving submodule 1.
And a third stage: in the touch detection stage, the data writing submodule 2 and the light emitting control submodule 4 are in a closed state, the touch detection submodule 3 is in an open state, the open touch detection submodule 3 controls the driving transistor T0 to output a touch detection signal to the touch signal reading terminal Sensor, and the touch detection signal is reduced along with the increase of the light intensity irradiated on the photosensitive device, so that the touch detection is realized.
In the display stage, the operation of the pixel circuit is also divided into three stages:
the first stage is as follows: an initialization phase in which the pixel circuit effects initialization of the data writing sub-module 2. At this stage, the touch detection submodule 3 and the light-emitting control submodule 4 are in an off state, and the data writing submodule 2 is Reset under the control of the Reset signal terminal Reset, so that the first terminal 2a of the data writing submodule 2 inputs an initial voltage value to the gate of the driving transistor T0.
And a second stage: and a data writing stage in which the pixel circuit implements data writing to the gate of the driving transistor T0. At this stage, the touch detection submodule 3 and the light-emitting control submodule 4 are in an off state, the data writing submodule 2 is in an on state under the control of the scanning signal terminal Scan, and the data writing submodule 2 transmits a data signal to the first terminal 1a of the driving submodule 1.
And a third stage: and in the light emitting driving stage, the data writing sub-module 2 and the touch detection sub-module 3 are in a closed state, the light emitting control sub-module 4 is in a conducting state, the light emitting control sub-module 4 with the light emitting device is connected with the drain electrode of the driving transistor T0, and the light emitting control sub-module 4 controls the driving transistor T0 to drive the light emitting device to emit light, so that the display function is realized.
The following is a detailed description of the specific structure and the operation principle of the data writing sub-module 2, the touch detection sub-module 3 and the light-emitting control sub-module 4 in the above pixel circuit provided by the embodiment of the present invention.
Specifically, in the pixel circuit provided in the embodiment of the present invention, the data writing sub-module 2, as shown in fig. 2a, fig. 2b, fig. 3a, fig. 3b, fig. 4a, fig. 4b, fig. 5a, and fig. 5b, may specifically include: a first switching transistor T1, a second switching transistor T2, a first capacitor Cst1, and a second capacitor Cst 2; wherein,
the gate of the first switching transistor T1 is connected to the Reset signal terminal Reset, the source of the first switching transistor T1 is connected to the third terminal 1c of the driving submodule 1, and the drain of the first switching transistor T1 is connected to the first terminal 1a of the driving submodule, the first terminal x1 of the first capacitor Cst1, and the first terminal y1 of the second capacitor Cst2, respectively;
a gate electrode of the second switching transistor T2 is connected to the Scan signal terminal Scan, a source electrode of the second switching transistor T2 is connected to the Data signal terminal Data, and a drain electrode of the second switching transistor T2 is connected to the second terminal x2 of the first capacitor Cst 1;
the second terminal y2 of the second capacitor Cst2 is respectively connected to the first reference signal terminal Ref1, the second terminal 1b of the driving sub-module 1, and the second terminal 3b of the touch detection sub-module 3.
In particular, when implemented, the first switching transistor T1 may be an N-type transistor, as shown in fig. 2a, 2b, 5a, and 5 b; the first switching transistor T1 may also be a P-type transistor, as shown in fig. 3a, 3b, 4a and 4b, but is not limited thereto. When the first switching transistor T1 is an N-type transistor, the first switching transistor T1 is in an on state when the signal of the Reset signal terminal Reset is at a high level; when the first switching transistor T1 is a P-type transistor, the first switching transistor T1 is in an on state when the signal of the Reset signal terminal Reset is at a low level.
In particular, when implemented, the second switching transistor T2 may be an N-type transistor, as shown in fig. 2a, 2b, 5a and 5 b; the second switching transistor T2 may also be a P-type transistor, as shown in fig. 3a, 3b, 4a and 4b, but is not limited thereto. When the second switching transistor T2 is an N-type transistor, the second switching transistor T2 is in an on state when the signal at the Scan signal terminal Scan is at a high level; when the second switching transistor T2 is a P-type transistor, the second switching transistor T2 is turned on when the signal at the Scan signal terminal Scan is low.
Further, in the above-mentioned pixel circuit provided in the embodiment of the present invention, in order to ensure that the driving transistor T0 can work normally, when the driving transistor T0 is an N-type transistor, the signal of the Data signal terminal Data in the Data writing stage should be a high level signal; when the driving transistor T0 is a P-type transistor, the signal of the Data signal terminal Data in the Data writing phase should be a low level signal.
Specifically, in the pixel circuit provided in the embodiment of the present invention, the touch detection sub-module 3, as shown in fig. 2a, fig. 2b, fig. 3a, fig. 3b, fig. 4a, fig. 4b, fig. 5a and fig. 5b, may further specifically include: a third switching transistor T3 and a fourth switching transistor T4; wherein,
the grid electrode of the third switching transistor T3 is connected with the touch control signal terminal Select, and the drain electrode of the third switching transistor T3 is connected with the first terminal p1 of the photosensitive device;
the source of the third switching transistor T3 is connected to the first terminal 1a of the driving submodule 1, and the second terminal p2 of the photosensitive device is connected to the first reference signal terminal Ref1, as shown in fig. 2a, 3a, 4a and 5 a; alternatively, the source of the third switching transistor T3 is connected to the first reference signal terminal Ref1, and the second terminal p2 of the photosensitive device is connected to the first terminal 1a of the driving submodule 1, as shown in fig. 2b, fig. 3b, fig. 4b and fig. 5 b;
the gate of the fourth switching transistor T4 is connected to the touch control signal terminal Select, the source of the fourth switching transistor T4 is connected to the third terminal 1c of the driving submodule 1, and the drain of the fourth switching transistor T4 is connected to the touch signal reading terminal Sensor.
Preferably, in practical implementation, as shown in fig. 2a, fig. 2b, fig. 3a, fig. 3b, fig. 4a, fig. 4b, fig. 5a and fig. 5b, the photosensitive device may be a photodiode pd (photo diode), and the used device is simple, convenient to implement and low in cost.
Specifically, in the touch detection sub-module 3, the positions of the photodiode PD and the third transistor T3 may be interchanged. In order to ensure that the photodiode PD is in a reverse bias state when operating, when the driving transistor T0 is an N-type transistor, the cathode of the photodiode PD is connected to the drain of the third switching transistor T3, and the anode of the photodiode PD is connected to the first reference signal terminal Ref1, as shown in fig. 2a and 3 a; alternatively, the photodiode PD and the third transistor T3 are interchanged, and as shown in fig. 2b and 3b, the anode of the photodiode PD is connected to the drain of the third switching transistor T3, and the cathode of the photodiode PD is connected to the gate of the driving transistor T0. When the driving transistor T0 is a P-type transistor, the anode of the photodiode PD is connected to the drain of the third switching transistor T3, and the cathode of the photodiode PD is connected to the first reference signal terminal Ref1, as shown in fig. 4a and 5 a; alternatively, the photodiode PD and the third transistor T3 are interchanged, as shown in fig. 4b and 5b, the cathode of the photodiode PD is connected to the drain of the third switching transistor T3, and the anode of the photodiode PD is connected to the gate of the driving transistor T0.
It should be noted that the photodiode PD is turned on when it is reverse biased and illuminated. The operating principle of the photodiode PD is: when the photodiode PD under the reverse bias is illuminated, that is, when the photodiode PD is not touched, the photodiode PD generates a photo-generated carrier under the action of the photoelectric effect to form a larger reverse current, and the larger the light intensity irradiated to the photodiode PD is, the larger the reverse current generated by the photodiode PD is.
In particular, when embodied, the third and fourth switching transistors T3 and T4 may be N-type transistors, as shown in fig. 2a, 2b, 5a, and 5 b; the third switching transistor T3 and the fourth switching transistor T4 may also be P-type transistors, as shown in fig. 3a, 3b, 4a and 4b, which is not limited herein.
Further, in specific implementation, when the third switching transistor T3 and the fourth switching transistor T4 are N-type transistors, when the signal of the touch control signal terminal Select is at a high level, the third switching transistor T3 and the fourth switching transistor T4 are in an on state; when the third switching transistor T3 and the fourth switching transistor T4 are P-type transistors, the third switching transistor T3 and the fourth switching transistor T4 are in an on state when the signal of the touch control signal terminal Select is at a low level.
Specifically, in the pixel circuit provided in the embodiment of the present invention, the light-emitting control sub-module 4, as shown in fig. 2a, fig. 2b, fig. 3a, fig. 3b, fig. 4a, fig. 4b, fig. 5a, and fig. 5b, may further specifically include: a fifth switching transistor T5; wherein,
a gate of the fifth switching transistor T5 is connected to the emission control signal terminal EM, and a drain of the fifth switching transistor T5 is connected to the first terminal z1 of the light emitting device; the source of the fifth switching transistor T5 is connected to the third terminal 1c of the driving submodule 1;
the second terminal z2 of the light emitting device is connected to the second reference signal terminal Ref2 as shown in fig. 2a, 3a, 4a and 5a, or the source of the fifth switching transistor T5 is connected to the second reference signal terminal Ref 2; the second terminal z2 of the light emitting device is connected to the third terminal 1c of the driver sub-module 1, as shown in fig. 2b, 3b, 4b and 5 b.
In practical implementation, the light emitting device in the pixel circuit provided by the embodiment of the present invention is generally an Organic Light Emitting Diode (OLED), and the light emitting device realizes light emitting display under the action of the on-state current of the driving transistor T0.
Further, in the foregoing lighting control sub-module 4, the positions of the OLED and the fifth switching transistor T5 may be interchanged, in order to ensure that the OLED can emit light normally, when the driving transistor T0 is an N-type transistor, the cathode of the OLED is connected to the drain of the fifth switching transistor T5, and the anode of the OLED is connected to the second reference signal terminal Ref2, as shown in fig. 2a and fig. 3 a; alternatively, the OLED and the fifth switching transistor T5 are interchanged, as shown in fig. 2b and 3b, the anode of the OLED is connected to the drain of the fifth switching transistor T5, and the cathode of the OLED is connected to the third terminal 1c of the driving sub-module 1. When the driving transistor T0 is a P-type transistor, the anode of the OLED is connected to the drain of the fifth switching transistor T5, and the cathode of the OLED is connected to the second reference signal terminal Ref2, as shown in fig. 4a and 5 a; alternatively, the OLED and the fifth switching transistor T5 are interchanged, as shown in fig. 4b and 5b, the cathode of the OLED is connected to the drain of the fifth switching transistor T5, and the anode of the OLED is connected to the third terminal 1 of the driving sub-module 1.
In particular, when implemented, the fifth switching transistor T5 may be an N-type transistor, as shown in fig. 2a, 2b, 5a and 5 b; the fifth switching transistor T5 may also be a P-type transistor, as shown in fig. 3a, 3b, 4a and 4b, but is not limited thereto. When the fifth switching transistor T5 is an N-type transistor, the fifth switching transistor T5 is in an on state when the signal output from the emission control signal terminal EM is at a high level; when the fifth switching transistor T5 is a P-type transistor, the fifth switching transistor T5 is in an on state when the signal output from the emission control signal terminal EM is at a low level.
It should be noted that, in the pixel circuit provided in the embodiments of the present invention, the driving Transistor and the switching Transistor may be a Thin Film Transistor (TFT) or a Metal Oxide semiconductor field effect Transistor (MOS), which is not limited herein. And the sources and drains of these transistors may be interchanged without specific distinction.
The following is a detailed description of the specific operating principle of the pixel circuit provided in the embodiments of the present invention through several specific examples. In the following example, when the driving transistor T0 is an N-type transistor, the voltage value Vss of the first reference signal terminal Ref1 is less than or equal to 0, and the voltage value V of the second reference signal terminal Ref2 is less than or equal to 0DD>0; when the driving transistor T0 is a P-type transistor, the voltage value V of the first reference signal terminal Ref1DD>0, and the voltage value Vss of the second reference signal terminal Ref2 is less than or equal to 0.
Example one:
as shown in fig. 2a and 2b, the driving transistor T0 is an N-type transistor, and the first transistor T1, the second switching transistor T2, the third switching transistor T3, the fourth switching transistor T4 and the fifth switching transistor T5 are also N-type transistors. FIG. 2c is the timing diagram of the circuits in FIG. 2a and FIG. 2b, wherein the voltage at the Scan signal terminal Scan is VScanThe voltage of Data signal terminal is VDataThe Reset signal terminal Reset has a voltage of VResetThe voltage of the touch control signal terminal Select is VSelectThe voltage of the light-emitting control signal end EM is VEMThe gate of the driving transistor T0 has a voltage V when touchedA1The gate of the driving transistor T0 has a voltage V when no touch occursA2
Specifically, the operating principle of the pixel circuit is as follows:
in the initialization phase of the touch phase, i.e. the first phase 1 of the touch phase, at this time, the voltage V of the Reset signal terminal Reset is setResetAt high level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from high level to low level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short high level to a low level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VSS. Meanwhile, the voltage V of the first reference signal terminal Ref1SSThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VSS+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state. At this time, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied regardless of whether the photodiode PD is touched or notA1And VA2Are all VSS+Vth
In the data writing stage of the touch stage, i.e. the second stage 2 of the touch stage, at this time, the scanning signalVoltage V at terminal ScanScanAnd voltage V of Data signal terminal DataDataAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VSS. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VSS+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VSS+VthThat is, data writing is realized at the gate of the driving transistor T0. At this stage, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied no matter whether the photodiode PD is touched or notA1And VA2Are all VData[C1/(C1+C2)]+VSS+Vth
In the touch detection stage of the touch stage, i.e. the third stage 3 of the touch stage, at this time, the voltage V of the touch control signal terminal SelectSelectAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of Scan signal terminal ScanScanVoltage V of Data signal terminal DataDataAnd voltage V of emission control signal terminal EMEMAt a low level, the third and fourth switching transistors T3 and T4 are in an on state, the first switching transistor T1, the second switching transistor T2, and the fifth switching transistor T4 are in an on stateThe off transistor T5 is in an off state.
At this time, if the photodiode PD is touched without light, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0A1Is still maintained at VData[C1/(C1+C2)]+VSS+VthTo turn on the driving transistor T0, the voltage V of the first reference signal terminal Ref1SSThe signal is inputted to the source of the driving transistor T0, and a touch detection signal is outputted through the drain of the driving transistor T0, and the touch detection signal is outputted to the touch signal reading terminal Sensor through the turned-on fourth switching transistor T4.
At this time, if the photodiode PD is illuminated, that is, if there is no touch, the photodiode PD generates photo-generated carriers under the action of the photoelectric effect, and the generated reverse current reduces the charges on the first capacitor Cst1 and the second capacitor Cst2, resulting in the gate voltage V input to the driving transistor T0A2And falls, thereby causing the touch detection signal outputted from the driving transistor T0 and outputted to the touch signal reading terminal Sensor through the fourth switching transistor T4 to become small. The magnitude of the touch detection signal is related to the light intensity irradiated to the photodiode PD, and the larger the light intensity is, the smaller the touch detection signal is.
In the initialization phase of the display phase, i.e. the first phase 1 of the display phase, the voltage V of the Reset signal terminal Reset is appliedResetAt high level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from high level to low level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short high level to a low level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first terminal y2The reference signal terminal Ref1 is connected, and the voltage at the second terminal y2 of the second capacitor Cst2 is VSS. Meanwhile, the voltage V of the first reference signal terminal Ref1SSThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VSS+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state.
In the data writing phase of the display phase, i.e. the second phase 2 of the display phase, the voltage V at the Scan signal terminal Scan is appliedScanAnd voltage V of Data signal terminal DataDataAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VSS. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VSS+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VSS+VthThat is, data writing is realized at the gate of the driving transistor T0.
In the third stage 3 of the display stage, which is the light emission driving stage of the display stage, the voltage V of the light emission control signal terminal EM is setEMAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of Scan signal terminal ScanScanVoltage V of Data signal terminal DataDataAnd voltage V of touch control signal terminal SelectSelectAt a low level, the first switching transistor T1, the second switching transistor T2, the third switching transistor T3, and the fourth switching transistor T4 are in an off state, the fifth switching transistor T5 is in an on state, and the OLED is turned on. The gate voltage of the driving transistor T0 is maintained at VData[C1/(C1+C2)]+VSS+VthAt this time, the voltage between the gate and the source of the driving transistor T0 is Vgs=Vg-Vs=VData[C1/(C1+C2)]+Vth+VSS-VSS=VData[C1/(C1+C2)]+Vth
Since the driving transistor T0 is operated in saturation, the on-state current i of the driving transistor T0 is known from the current characteristic in saturationdSatisfies the formula: i.e. id=K(Vgs-Vth)2=K{VData[C1/(C1+C2)]+Vth-Vth}2=K{VData[C1/(C1+C2)]}2Where K is a structural parameter, this number is relatively stable in the same structure and can be calculated as a constant. As can be derived from the formula, the leakage current flowing through the driving transistor T0 is only equal to the voltage V at the data signal terminalDataAnd the capacitance values of the first capacitor Cst1 and the second capacitor Cst2 are related to the threshold voltage V of the driving transistor T0thIs irrelevant. Therefore, with the on-state current idThe light emitting device is driven to emit light, the current flowing through each OLED is relatively uniform, and the threshold voltage V cannot be caused by the backboard manufacturing processthThe non-uniformity causes different currents flowing through the OLEDs, resulting in non-uniform brightness.
In summary, in the above-mentioned pixel circuit, when the photodiode PD is touched in the touch stage, the Sensor outputs the touch signal from the touch signal reading terminalThe touch sensing signal is larger than the touch sensing signal output by the Sensor of the touch signal reading end when no touch occurs, whether the touch screen has touch can be determined by analyzing the size of the touch sensing signal output by the pixel circuit, and then the position of a contact is determined, so that the touch sensing function is realized. The pixel circuit drives the threshold voltage V of the transistor T0 in the display stagethStored on the second capacitor Cst2, ensuring the driving voltage for OLED to emit light and the voltage V of the data signalDATARelated to the threshold voltage V of the driving transistor T0thIrrelevantly, the threshold voltage V is avoidedthThe influence on the OLED, namely when the same data signal is loaded to different pixel units, images with the same brightness can be obtained, and the uniformity of the image brightness of the display area of the display device is improved.
Example two:
as shown in fig. 3a and 3b, the driving transistor T0 is an N-type transistor, and the first transistor T1, the second switching transistor T2, the third switching transistor T3, the fourth switching transistor T4 and the fifth switching transistor T5 are P-type transistors. FIG. 3c is the timing diagram of the circuits in FIG. 3a and FIG. 3b, wherein the voltage at the Scan signal terminal Scan is VScanThe voltage of Data signal terminal is VDataThe Reset signal terminal Reset has a voltage of VResetThe voltage of the touch control signal terminal Select is VSelectThe voltage of the light-emitting control signal end EM is VEMThe gate of the driving transistor T0 has a voltage V when touchedA1The gate of the driving transistor T0 has a voltage V when no touch occursA2
Specifically, the operating principle of the pixel circuit is as follows:
in the initialization phase of the touch phase, i.e. the first phase 1 of the touch phase, at this time, the voltage V of the Reset signal terminal Reset is setResetAt low level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the first switching transistor T1 is in an on state, the third switching transistor T3, the fourth switching transistor T4 and the fifth switching transistor T3The transistor T5 is in the off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from low level to high level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short high level to a low level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VSS. Meanwhile, the voltage V of the first reference signal terminal Ref1SSThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VSS+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state. At this time, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied regardless of whether the photodiode PD is touched or notA1And VA2Are all VSS+Vth
In the data writing stage of the touch stage, i.e. the second stage 2 of the touch stage, at this time, the voltage V of the Scan signal terminal ScanScanAt low level, voltage V of Data signal terminal DataDataVoltage V of Reset signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VSS. Data signal V outputted from Data signal terminal DataDataWriting through the source of the second switching transistor T2The second terminal x2 of the first capacitor Cst1 connected to the drain thereof changes the voltage at the second terminal x2 of the first capacitor Cst1 to VDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VSS+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VSS+VthThat is, data writing is realized at the gate of the driving transistor T0. At this stage, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied no matter whether the photodiode PD is touched or notA1And VA2Are all VData[C1/(C1+C2)]+VSS+Vth
In the touch detection stage of the touch stage, i.e. the third stage 3 of the touch stage, at this time, the voltage V of the Data signal terminal DataDataAnd voltage V of Select at touch control signal terminalSelectAt low level, resetting voltage V of signal terminal ResetResetVoltage V of Scan signal terminal ScanScanAnd voltage V of emission control signal terminal EMEMAt a high level, the third and fourth switching transistors T3 and T4 are in an on state, and the first, second, and fifth switching transistors T1, T2 and T5 are in an off state.
At this time, if the photodiode PD is touched without light, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0A1Is still maintained at VData[C1/(C1+C2)]+VSS+VthTo turn on the driving transistor T0, the voltage V of the first reference signal terminal Ref1SSThe signal is inputted to the source of the driving transistor T0, and a touch detection signal is outputted through the drain of the driving transistor T0, and the touch detection signal is outputted to the touch signal reading terminal Sensor through the turned-on fourth switching transistor T4.
At this time, if the photodiodeWhen the PD is under light, i.e. no touch, the photodiode PD generates photo-generated carriers under the action of the photoelectric effect, and the generated reverse current reduces the charges on the first capacitor Cst1 and the second capacitor Cst2, resulting in the gate voltage V0 input to the driving transistor T0A2And falls, thereby causing the touch detection signal outputted from the driving transistor T0 and outputted to the touch signal reading terminal Sensor through the fourth switching transistor T4 to become small. The magnitude of the touch detection signal is related to the light intensity irradiated to the photodiode PD, and the larger the light intensity is, the smaller the touch detection signal is.
In the initialization phase of the display phase, i.e. the first phase 1 of the display phase, the voltage V of the Reset signal terminal Reset is appliedResetAt low level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from low level to high level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short high level to a low level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VSS. Meanwhile, the voltage V of the first reference signal terminal Ref1SSThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VSS+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state.
At the display stageThe data writing phase of the segment is the second phase 2 of the display phase, at this time, the voltage V of the Scan signal terminal ScanScanAt low level, voltage V of Data signal terminal DataDataVoltage V of Reset signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VSS. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VSS+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VSS+VthThat is, data writing is realized at the gate of the driving transistor T0.
In the third phase 3 of the display phase, which is the light-emitting driving phase of the display phase, the voltage V of the Data signal terminal DataDataAnd voltage V of emission control signal terminal EMEMAt low level, resetting voltage V of signal terminal ResetResetVoltage V of Scan signal terminal ScanScanAnd the voltage V of the touch control signal terminal SelsctSelectAt a high level, the first switching transistor T1, the second switching transistor T2, the third switching transistor T3, and the fourth switching transistor T4 are in an off state, the fifth switching transistor T5 is in an on state, and the OLED is turned on. The gate voltage of the driving transistor T0 is maintained at VData[C1/(C1+C2)]+VSS+VthAt this time, the voltage between the source and the gate of the driving transistor T0 is Vgs=Vg-Vs=VData[C1/(C1+C2)]+VSS+Vth-VSS=VData[C1/(C1+C2)]+Vth
Since the driving transistor T0 is operated in saturation, the on-state current i of the driving transistor T0 is known from the current characteristic in saturationdSatisfies the formula: i.e. id=K(Vgs-Vth)2=K{VData[C1/(C1+C2)]+Vth-Vth}2=K{VData[C1/(C1+C2)]}2Where K is a structural parameter, this number is relatively stable in the same structure and can be calculated as a constant. As can be derived from the formula, the leakage current flowing through the driving transistor T0 is only equal to the voltage V at the data signal terminalDataAnd the capacitance values of the first capacitor Cst1 and the second capacitor Cst2 are related to the threshold voltage V of the driving transistor T0thIs irrelevant. Therefore, with the on-state current idThe light emitting device is driven to emit light, the current flowing through each OLED is relatively uniform, and the threshold voltage V cannot be caused by the backboard manufacturing processthThe non-uniformity causes different currents flowing through the OLEDs, resulting in non-uniform brightness.
In summary, in the pixel circuit, in the touch stage, when the photodiode PD is touched, the touch sensing signal output by the touch signal reading terminal Sensor is greater than the touch sensing signal output by the touch signal reading terminal when the photodiode PD is not touched, and the presence or absence of touch on the touch screen can be determined by analyzing the magnitude of the touch sensing signal output by the pixel circuit, so as to determine the position of the touch point, thereby implementing the touch detection function. The pixel circuit drives the threshold voltage V of the transistor T0 in the display stagethStored on the second capacitor Cst2, ensures the driving voltage for the OLED to emit light and the voltage V of the data signalDATARelated to the threshold voltage V of the driving transistor T0thIrrelevantly, the threshold voltage V is avoidedthInfluence on the OLED, i.e. when the same data signal is applied to different pixel cells, a graph with the same brightness can be obtainedThe uniformity of the image brightness in the display area of the display device is improved.
Example three:
as shown in fig. 4a and 4b, the driving transistor T0 is a P-type transistor, and the first transistor T1, the second switching transistor T2, the third switching transistor T3, the fourth switching transistor T4 and the fifth switching transistor T5 are also P-type transistors. FIG. 4c is the timing diagram of the circuits in FIG. 4a and FIG. 4b, wherein the voltage at the Scan signal terminal Scan is VScanThe voltage of Data signal terminal is VDataThe Reset signal terminal Reset has a voltage of VResetThe voltage of the touch control signal terminal Select is VSelectThe voltage of the light-emitting control signal end EM is VEMThe gate of the driving transistor T0 has a voltage V when touchedA1The gate of the driving transistor T0 has a voltage V when no touch occursA2
Specifically, the operating principle of the pixel circuit is as follows:
in the initialization phase of the touch phase, i.e. the first phase 1 of the touch phase, at this time, the voltage V of the Reset signal terminal Reset is setResetAt low level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from low level to high level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short low level to a high level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VDD. Meanwhile, the voltage V of the first reference signal terminal Ref1DDThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the second capacitor CstThe voltage value V of the first terminal y1 of the capacitor Cst2AIs a VDD+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state. At this time, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied regardless of whether the photodiode PD is touched or notA1And VA2Are all VDD+Vth
In the data writing stage of the touch stage, i.e. the second stage 2 of the touch stage, at this time, the voltage V of the Scan signal terminal ScanScanAnd voltage V of Data signal terminal DataDataAt low level, resetting voltage V of signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VDD. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VDD+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VDD+VthThat is, data writing is realized at the gate of the driving transistor T0. At this stage, the photodiode PD is in an off state regardless of the photodiode PD presence or absence of touch, driving the gate voltage V of transistor T0A1And VA2Are all VData[C1/(C1+C2)]+VDD+Vth
In the touch detection stage of the touch stage, i.e. the third stage 3 of the touch stage, at this time, the voltage V of the touch control signal terminal SelectSelectAt low level, resetting voltage V of signal terminal ResetResetVoltage V of Scan signal terminal ScanScanVoltage V of Data signal terminal DataDataAnd voltage V of emission control signal terminal EMEMAt a high level, the third and fourth switching transistors T3 and T4 are in an on state, and the first, second, and fifth switching transistors T1, T2 and T5 are in an off state.
At this time, if the photodiode PD is touched without light, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0A1Is still maintained at VData[C1/(C1+C2)]+VDD+VthTo turn on the driving transistor T0, the voltage V of the first reference signal terminal Ref1DDThe signal is inputted to the source of the driving transistor T0, and a touch detection signal is outputted through the drain of the driving transistor T0, and the touch detection signal is outputted to the touch signal reading terminal Sensor through the turned-on fourth switching transistor T4.
At this time, if the photodiode PD is illuminated, that is, if there is no touch, the photodiode PD generates photo-generated carriers under the action of the photoelectric effect, and the generated reverse current increases the charges on the first capacitor Cst1 and the second capacitor Cst2, resulting in the gate voltage V input to the driving transistor T0A2And rises, thereby causing the touch detection signal outputted from the driving transistor T0 and outputted to the touch signal reading terminal Sensor through the fourth switching transistor T4 to become small. The magnitude of the touch detection signal is related to the light intensity irradiated to the photodiode PD, and the larger the light intensity is, the smaller the touch detection signal is.
In the initialization phase of the display phase, i.e. the first phase 1 of the display phase, the voltage of the Reset signal terminal Reset is appliedVResetAt low level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from low level to high level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short low level to a high level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VDD. Meanwhile, the voltage V of the first reference signal terminal Ref1DDThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VDD+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state.
In the data writing phase of the display phase, i.e. the second phase 2 of the display phase, the voltage V at the Scan signal terminal Scan is appliedScanAnd voltage V of Data signal terminal DataDataAt low level, resetting voltage V of signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt a high level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VDD. From the data signal terminal DData signal V output by ataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VDD+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VDD+VthThat is, data writing is realized at the gate of the driving transistor T0.
In the third stage 3 of the display stage, which is the light emission driving stage of the display stage, the voltage V of the light emission control signal terminal EM is setEMAt low level, resetting voltage V of signal terminal ResetResetVoltage V of Scan signal terminal ScanScanVoltage V of Data signal terminal DataDataAnd voltage V of touch control signal terminal SelectSelectAt a high level, the first switching transistor T1, the second switching transistor T2, the third switching transistor T3, and the fourth switching transistor T4 are in an off state, the fifth switching transistor T5 is in an on state, and the OLED is turned on. The gate voltage of the driving transistor T0 is maintained at VData[C1/(C1+C2)]+VDD+VthAt this time, the voltage between the source and the gate of the driving transistor T0 is Vgs=Vg-Vs=VData[C1/(C1+C2)]+VDD+Vth-VDD=VData[C1/(C1+C2)]+Vth
Since the driving transistor T0 is operated in saturation, the on-state current i of the driving transistor T0 is known from the current characteristic in saturationdSatisfies the formula: i.e. id=K(Vgs-Vth)2=K{VData[C1/(C1+C2)]+Vth-Vth}2=K{VData[C1/(C1+C2)]}2Wherein K is a structural parameter,this value is relatively stable in the same structure and can be calculated as a constant. As can be derived from the formula, the leakage current flowing through the driving transistor T0 is only equal to the voltage V at the data signal terminalDataAnd the capacitance values of the first capacitor Cst1 and the second capacitor Cst2 are related to the threshold voltage V of the driving transistor T0thIs irrelevant. Therefore, with the on-state current idThe light emitting device is driven to emit light, the current flowing through each OLED is relatively uniform, and the threshold voltage V cannot be caused by the backboard manufacturing processthThe non-uniformity causes different currents flowing through the OLEDs, resulting in non-uniform brightness.
In summary, in the pixel circuit, in the touch stage, when the photodiode PD is touched, the touch sensing signal output by the touch signal reading terminal Sensor is greater than the touch sensing signal output by the touch signal reading terminal Sensor when the photodiode PD is not touched, and the presence or absence of touch on the touch screen can be determined by analyzing the magnitude of the touch sensing signal output by the pixel circuit, so as to determine the position of the touch point, thereby implementing the touch detection function. The pixel circuit drives the threshold voltage V of the transistor T0 in the display stagethStored on the second capacitor Cst2, ensuring the driving voltage for OLED to emit light and the voltage V of the data signalDATARelated to the threshold voltage V of the driving transistor T0thIrrelevantly, the threshold voltage V is avoidedthThe influence on the OLED, namely when the same data signal is loaded to different pixel units, images with the same brightness can be obtained, and the uniformity of the image brightness of the display area of the display device is improved.
Example four:
as shown in fig. 5a and 5b, the driving transistor T0 is a P-type transistor, and the first transistor T1, the second switching transistor T2, the third switching transistor T3, the fourth switching transistor T4 and the fifth switching transistor T5 are N-type transistors. FIG. 5c is the timing diagram of the circuits in FIG. 5a and FIG. 5b, wherein the voltage at the Scan signal terminal Scan is VScanThe voltage of Data signal terminal is VDataThe Reset signal terminal Reset has a voltage of VResetThe voltage of the touch control signal terminal Select is VSelectLight emitting control signalVoltage at terminal EM is VEMThe gate of the driving transistor T0 has a voltage V when touchedA1The gate of the driving transistor T0 has a voltage V when no touch occursA2
Specifically, the operating principle of the pixel circuit is as follows:
in the initialization phase of the touch phase, i.e. the first phase 1 of the touch phase, at this time, the voltage V of the Reset signal terminal Reset is setResetAt high level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from high level to low level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short low level to a high level in synchronization with the voltage of the scan signal terminal. At this time, the second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VDD. Meanwhile, the voltage V of the first reference signal terminal Ref1DDThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VDD+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state. At this time, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied regardless of whether the photodiode PD is touched or notA1And VA2Are all VDD+Vth
Data writing stage in touch stage, i.e. the second stage of touch stageStage 2, at this time, the voltage V of the Scan signal terminal ScanScanAt high level, voltage V of Data signal terminal DataDataVoltage V of Reset signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VDD. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VDD+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VDD+VthThat is, data writing is realized at the gate of the driving transistor T0. At this stage, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0 is applied no matter whether the photodiode PD is touched or notA1And VA2Are all VData[C1/(C1+C2)]+VDD+Vth
In the touch detection stage of the touch stage, i.e. the third stage 3 of the touch stage, at this time, the voltage V of the Data signal terminal DataDataAnd voltage V of Select at touch control signal terminalSelectAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of Scan signal terminal ScanScanAnd voltage V of emission control signal terminal EMEMAt a low level, the third and fourth switching transistors T3 and T4 are in an on state, the first and fourth switching transistors T1 and TThe two switching transistors T2 and the fifth switching transistor T5 are in an off state.
At this time, if the photodiode PD is touched without light, the photodiode PD is in an off state, and the gate voltage V of the driving transistor T0A1Is still maintained at VData[C1/(C1+C2)]+VDD+VthTo turn on the driving transistor T0, the voltage V of the first reference signal terminal Ref1DDThe signal is inputted to the source of the driving transistor T0, and a touch detection signal is outputted through the drain of the driving transistor T0, and the touch detection signal is outputted to the touch signal reading terminal Sensor through the turned-on fourth switching transistor T4.
At this time, if the photodiode PD is illuminated, that is, if there is no touch, the photodiode PD generates photo-generated carriers under the action of the photoelectric effect, and the generated reverse current increases the charges on the first capacitor Cst1 and the second capacitor Cst2, resulting in the gate voltage V input to the driving transistor T0A2And rises, thereby causing the touch detection signal outputted from the driving transistor T0 and outputted to the touch signal reading terminal Sensor through the fourth switching transistor T4 to become small. The magnitude of the touch detection signal is related to the light intensity irradiated to the photodiode PD, and the larger the light intensity is, the smaller the touch detection signal is.
In the initialization phase of the display phase, i.e. the first phase 1 of the display phase, the voltage V of the Reset signal terminal Reset is appliedResetAt high level, voltage V of Select at touch control signal terminalSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the first switching transistor T1 is in an on state, and the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The turned-on first switching transistor T1 makes the driving transistor T0 a diode connection. Voltage V of Scan signal terminal ScanScanChange from high level to low level temporarily while the voltage V of Data signal terminal DataDataThe driving transistor T0, which is changed into the diode connection mode, is turned on from a short low level to a high level in synchronization with the voltage of the scan signal terminal. At this time, the secondThe second terminal y2 of the capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 is VDD. Meanwhile, the voltage V of the first reference signal terminal Ref1DDThe second capacitor Cst2 is charged via the driving transistor T0 and the first switching transistor T1 to the voltage value V of the first terminal y1 of the second capacitor Cst2AIs a VDD+VthThe driving transistor T0 is turned off, wherein the threshold voltage of the driving transistor T0 is VthAt this time, the voltage difference across the second capacitor Cst2 is VthStorage of the threshold voltage of the driving transistor T0 at the first terminal y1 of the second capacitor Cst2 is achieved, leaving the data writing submodule 2 in an initialized state.
In the data writing phase of the display phase, i.e. the second phase 2 of the display phase, the voltage V at the Scan signal terminal Scan is appliedScanAt high level, voltage V of Data signal terminal DataDataVoltage V of Reset signal terminal ResetResetVoltage V of touch control signal terminal SelectSelectAnd voltage V of emission control signal terminal EMEMAt the low level, the second switching transistor T2 is in an on state, and the first switching transistor T1, the third switching transistor T3, the fourth switching transistor T4, and the fifth switching transistor T5 are in an off state. The second terminal y2 of the second capacitor Cst2 is directly connected to the first reference signal terminal Ref1, and the voltage at the second terminal y2 of the second capacitor Cst2 becomes VDD. Data signal V outputted from Data signal terminal DataDataThe voltage at the second terminal x2 of the first capacitor Cst1 is changed to V by writing the second terminal x2 of the first capacitor Cst1 connected to the drain of the second switching transistor T2 through the source thereofDataAt this time, the coupling voltage of the first capacitor Cst1 and the second capacitor Cst2 at the connection thereof, i.e. the first terminal y1 of the second capacitor Cst2, is VData[C1/(C1+C2)]+VDD+VthWhere C1 and C2 are capacitance values of the first capacitor Cst1 and the second capacitor Cst2, respectively. The first terminal y1 of the second capacitor C2 is connected to the gate of the driving transistor T0, and the gate of the driving transistor T0 is also at a voltage VData[C1/(C1+C2)]+VDD+VthI.e. at the gate of the drive transistor T0And (6) writing data.
In the third phase 3 of the display phase, which is the light-emitting driving phase of the display phase, the voltage V of the Data signal terminal DataDataAnd voltage V of emission control signal terminal EMEMAt high level, resetting the voltage V of the signal terminal ResetResetVoltage V of Scan signal terminal ScanScanAnd the voltage V of the touch control signal terminal SelsctSelectAt a low level, the first switching transistor T1, the second switching transistor T2, the third switching transistor T3, and the fourth switching transistor T4 are in an off state, the fifth switching transistor T5 is in an on state, and the OLED is turned on. The gate voltage of the driving transistor T0 is maintained at VData[C1/(C1+C2)]+VDD+VthAt this time, the voltage between the source and the gate of the driving transistor T0 is Vgs=Vg-Vs=VData[C1/(C1+C2)]+VDD+Vth-VDD=VData[C1/(C1+C2)]+Vth
Since the driving transistor T0 is operated in saturation, the on-state current i of the driving transistor T0 is known from the current characteristic in saturationdSatisfies the formula: i.e. id=K(Vgs-Vth)2=K{VData[C1/(C1+C2)]+Vth-Vth}2=K{VData[C1/(C1+C2)]}2Where K is a structural parameter, this number is relatively stable in the same structure and can be calculated as a constant. As can be derived from the formula, the leakage current flowing through the driving transistor T0 is only equal to the voltage V at the data signal terminalDataAnd the capacitance values of the first capacitor Cst1 and the second capacitor Cst2 are related to the threshold voltage V of the driving transistor T0thIs irrelevant. Therefore, with the on-state current idThe light emitting device is driven to emit light, the current flowing through each OLED is relatively uniform, and the threshold voltage V cannot be caused by the backboard manufacturing processthThe non-uniformity causes different currents flowing through the OLEDs, resulting in non-uniform brightness.
In summary, in the touch stage of the pixel circuit, when the photodiode PD is touchedWhen the touch sensing signal output by the Sensor is larger than the touch sensing signal output by the Sensor when no touch occurs, the touch sensing signal output by the pixel circuit is analyzed to determine whether the touch screen has touch, so that the position of a contact point is determined, and the touch sensing function is realized. The pixel circuit drives the threshold voltage V of the transistor T0 in the display stagethStored on the second capacitor Cst2, ensures the driving voltage for the OLED to emit light and the voltage V of the data signalDATARelated to the threshold voltage V of the driving transistor T0thIrrelevantly, the threshold voltage V is avoidedthThe influence on the OLED, namely when the same data signal is loaded to different pixel units, images with the same brightness can be obtained, and the uniformity of the image brightness of the display area of the display device is improved.
Based on same utility model conceive, the embodiment of the utility model provides an organic electroluminescence display panel is still provided, include the embodiment of the utility model provides an above-mentioned pixel circuit, because the principle of this organic electroluminescence display panel solution problem is similar with aforementioned a pixel circuit, consequently this organic electroluminescence display panel's implementation can refer to pixel circuit's implementation, and repeated part is no longer repeated.
Based on same utility model conceive, the embodiment of the utility model provides a still provide a display device, include the embodiment of the utility model provides an above-mentioned organic electroluminescence display panel, this display device can be display, cell-phone, TV, notebook, all-in-one etc. be the ordinary technical personnel in this field that other indispensable components to display device should understand having, do not do the perplexing here, also should not regard as right the utility model discloses a restriction.
The embodiment of the utility model provides a pair of pixel circuit, organic electroluminescent display panel and display device, this pixel circuit includes: the drive submodule, the data write-in submodule, the touch control detection submodule with a photosensitive device and the light-emitting control submodule with a light-emitting device; under the control of a reset signal end, a scanning signal end and a data signal end, the data writing submodule transmits a data signal to the first end of the driving submodule; under the control of a touch control signal end, the touch detection submodule controls the driving submodule to output a touch detection signal to the touch signal reading end, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device, so that the touch detection function is realized; under the control of the light-emitting control signal end, the light-emitting control submodule controls the driving submodule to drive the light-emitting device to emit light, and the display driving function is realized. The pixel circuit integrates touch control and display functions, so that the manufacturing cost for respectively arranging the display driving circuit and the touch control circuit can be saved, and the thickness of the display panel can be reduced.
It will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims and their equivalents, the present invention is also intended to include such modifications and variations.

Claims (12)

1. A pixel circuit, comprising: the drive submodule, the data write-in submodule, the touch control detection submodule with a photosensitive device and the light-emitting control submodule with a light-emitting device; wherein,
the first end of the driving sub-module is respectively connected with the first end of the data writing sub-module and the first end of the touch detection sub-module, the second end of the driving sub-module is respectively connected with the second end of the data writing sub-module, the second end of the touch detection sub-module and the first reference signal end, and the third end of the driving sub-module is respectively connected with the third end of the data writing sub-module, the third end of the touch detection sub-module and the first end of the light-emitting control sub-module;
the fourth end of the data writing submodule is connected with a reset signal end, the fifth end of the data writing submodule is connected with a scanning signal end, and the sixth end of the data writing submodule is connected with a data signal end; under the control of the reset signal terminal, the scanning signal terminal and the data signal terminal, the data writing submodule transmits a data signal to the first terminal of the driving submodule;
the fourth end of the touch detection submodule is connected with a touch control signal end, and the fifth end of the touch detection submodule is connected with a touch signal reading end; under the control of the touch control signal end, the touch detection submodule controls the driving submodule to output a touch detection signal to the touch signal reading end, and the touch detection signal is reduced along with the increase of the light intensity of the photosensitive device;
the second end of the light-emitting control sub-module is connected with a second reference signal end, and the third end of the light-emitting control sub-module is connected with a light-emitting control signal end; and under the control of the light-emitting control signal end, the light-emitting control submodule controls the driving submodule to drive the light-emitting device to emit light.
2. The pixel circuit of claim 1, wherein the first and second terminals of the driver sub-module are signal input terminals and the third terminal of the driver sub-module is a signal output terminal;
the first end of the data writing sub-module is a signal output end, and the second end, the third end, the fourth end, the fifth end and the sixth end of the data writing sub-module are signal input ends;
the first end of the touch detection submodule is a signal input end, and the second end of the touch detection submodule is a signal output end, or the first end of the touch detection submodule is a signal output end, and the second end of the touch detection submodule is a signal input end; the third end and the fourth end of the touch detection sub-module are signal input ends, and the fifth end of the touch detection sub-module is a signal output end;
the first end of the light-emitting control sub-module is a signal input end, and the second end of the light-emitting control sub-module is a signal output end, or the first end of the light-emitting control sub-module is a signal output end, and the second end of the light-emitting control sub-module is a signal input end; and the third end of the light-emitting control submodule is a signal input end.
3. The pixel circuit according to claim 2, wherein the driver sub-module specifically comprises: a drive transistor; wherein,
the grid electrode of the driving transistor is the first end of the driving submodule, the source electrode of the driving transistor is the second end of the driving submodule, and the drain electrode of the driving transistor is the third end of the driving submodule.
4. The pixel circuit according to claim 3, wherein the driving transistor is an N-type transistor, the voltage of the first reference signal terminal is a negative voltage or a zero voltage, and the voltage of the second reference signal terminal is a positive voltage;
the driving transistor is a P-type transistor, the voltage of the first reference signal end is positive, and the voltage of the second reference signal end is negative voltage or zero voltage.
5. The pixel circuit according to claim 1 or 2, wherein the data writing submodule specifically comprises: a first switching transistor, a second switching transistor, a first capacitor and a second capacitor; wherein,
the grid electrode of the first switch transistor is connected with the reset signal end, the source electrode of the first switch transistor is connected with the third end of the driving submodule, and the drain electrode of the first switch transistor is respectively connected with the first end of the driving submodule, the first end of the first capacitor and the first end of the second capacitor;
the grid electrode of the second switch transistor is connected with the scanning signal end, the source electrode of the second switch transistor is connected with the data signal end, and the drain electrode of the second switch transistor is connected with the second end of the first capacitor;
and the second end of the second capacitor is respectively connected with the first reference signal end, the second end of the driving submodule and the second end of the touch detection submodule.
6. The pixel circuit according to claim 5, wherein the first switching transistor is an N-type transistor or a P-type transistor; and/or the second switch transistor is an N-type transistor or a P-type transistor.
7. The pixel circuit according to claim 1 or 2, wherein the touch detection sub-module further comprises: a third switching transistor and a fourth switching transistor; wherein,
the grid electrode of the third switching transistor is connected with the touch control signal end, and the drain electrode of the third switching transistor is connected with the first end of the photosensitive device;
the source electrode of the third switching transistor is connected with the first end of the driving submodule, and the second end of the photosensitive device is connected with the first reference signal end; or, the source of the third switching transistor is connected with the first reference signal end, and the second end of the photosensitive device is connected with the first end of the driving submodule;
the grid electrode of the fourth switching transistor is connected with the touch control signal end, the source electrode of the fourth switching transistor is connected with the third end of the driving submodule, and the drain electrode of the fourth switching transistor is connected with the touch signal reading end.
8. The pixel circuit according to claim 7, wherein the third switching transistor and the fourth switching transistor are N-type transistors; or, the third switching transistor and the fourth switching transistor are P-type transistors.
9. The pixel circuit according to claim 1 or 2, wherein the emission control sub-module further comprises: a fifth switching transistor; wherein,
the grid electrode of the fifth switching transistor is connected with the light-emitting control signal end, and the drain electrode of the fifth switching transistor is connected with the first end of the light-emitting device;
the source electrode of the fifth switching transistor is connected with the third end of the driving submodule, and the second end of the light-emitting device is connected with the second reference signal end; or, the source of the fifth switching transistor is connected to the second reference signal terminal; and the second end of the light-emitting device is connected with the third end of the driving sub-module.
10. The pixel circuit according to claim 9, wherein the fifth switching transistor is an N-type transistor or a P-type transistor.
11. An organic electroluminescent display panel comprising the pixel circuit according to any one of claims 1 to 10.
12. A display device comprising the organic electroluminescent display panel according to claim 11.
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CN103413523A (en) * 2013-07-31 2013-11-27 京东方科技集团股份有限公司 Pixel circuit, organic electroluminescence display panel and display device
WO2015172465A1 (en) * 2014-05-14 2015-11-19 京东方科技集团股份有限公司 Pixel drive circuit, drive method, array substrate and display device
WO2016000333A1 (en) * 2014-06-30 2016-01-07 京东方科技集团股份有限公司 Pixel circuit, organic electroluminescent display panel and display device
CN110444158A (en) * 2019-08-19 2019-11-12 京东方科技集团股份有限公司 Pixel-driving circuit and its driving method, display panel and display device

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103413523A (en) * 2013-07-31 2013-11-27 京东方科技集团股份有限公司 Pixel circuit, organic electroluminescence display panel and display device
WO2015014147A1 (en) * 2013-07-31 2015-02-05 京东方科技集团股份有限公司 Pixel circuit, organic electroluminescence display panel, and display apparatus
US9495908B2 (en) 2013-07-31 2016-11-15 Boe Technology Group Co., Ltd. Pixel circuit, organic electroluminescent display panel and display device
WO2015172465A1 (en) * 2014-05-14 2015-11-19 京东方科技集团股份有限公司 Pixel drive circuit, drive method, array substrate and display device
US9760199B2 (en) 2014-05-14 2017-09-12 Boe Technology Group., Ltd. Pixel driving circuit and driving method thereof, array substrate and display apparatus
WO2016000333A1 (en) * 2014-06-30 2016-01-07 京东方科技集团股份有限公司 Pixel circuit, organic electroluminescent display panel and display device
US9703414B2 (en) 2014-06-30 2017-07-11 Boe Technology Group Co., Ltd. Pixel circuit, organic electroluminescent display panel and display apparatus
CN110444158A (en) * 2019-08-19 2019-11-12 京东方科技集团股份有限公司 Pixel-driving circuit and its driving method, display panel and display device
CN110444158B (en) * 2019-08-19 2021-02-02 京东方科技集团股份有限公司 Pixel driving circuit and driving method thereof, display panel and display device
US11367395B2 (en) 2019-08-19 2022-06-21 Boe Technology Group Co., Ltd. Pixel driving circuit and driving method therefor, display panel and display apparatus

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