Pixel driving circuit and display panel

Abstract

The invention discloses a pixel driving circuit and a display panel. The pixel driving circuit comprises a display driving circuit and a sensing driving circuit in each pixel area. The sensing driving circuit comprises a sensing unit, a first storage module and a sensing control module, the sensing unit is used for generating an induced current after receiving target light, the first storage module is used for storing the induced current, and the sensing control module is used for controlling the induced current to be stored in the first storage module; the display driving circuit comprises a data input module, a light-emitting control module and a light-emitting unit, and the data input module is connected to the first storage module and used for receiving the induction current from the storage module and inputting the induction current to the first light-emitting control module to drive the light-emitting unit to display. According to the invention, the sensing driving circuit and the display driving circuit are deeply combined, so that the function of displaying while sensing is realized.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a pixel driving circuit and a display panel. Background Art

[0002] With the advancement of display technology, light sensors are being added to or within display panels to detect non-visible light, such as X-rays, or other visible light, enabling fingerprint recognition or object detection. In particular, X-ray detection, such as in medical X-ray inspection equipment, luggage inspection, and security scanning, can be directly displayed on the display panel, greatly improving convenience.

[0003] However, the detection result of the light sensor needs to be processed by the detection processing module, sent to the system chip, and then input to the display module via the display driver chip for display, resulting in a high complexity of the system. Summary of the Invention

[0004] The purpose of this application is to provide a pixel driver circuit and display panel that deeply integrates the sensing driver circuit and the display driver circuit, allowing sensing and display to be performed step by step, achieving a sense-and-display function. The detection results of this application do not need to be processed by the detection processing module, sent to the system-level chip, and then displayed by the display driver circuit. This reduces system complexity, material costs, and power consumption.

[0005] The present application discloses a pixel driving circuit, which includes a display driving circuit and a sensing driving circuit in each pixel area; the sensing driving circuit includes a sensing unit, a first storage module and a sensing control module, the sensing unit is used to generate an induced current after receiving target light, the first storage module is used to store the induced current, and the sensing control module is used to control the storage of the induced current in the first storage module; the display driving circuit includes a data input module, a light control module and a light unit, the data input module is connected to the first storage module, and is used to receive the induced current from the storage module and input the induced current into the light control module to drive the light unit to display.

[0006] Optionally, the display driving circuit also includes a second storage module, a reset module, a threshold compensation module and a first driving transistor; the data input module is connected to the first node, the input end of the first driving transistor is connected to the first node, the control end of the driving transistor is connected to the second node, and the output end of the driving transistor is connected to the third node; one end of the second storage module is connected to the power supply voltage end, and the other end of the second storage module is connected to the second node; one end of the light-emitting unit is connected to the fourth node, and the other end of the light-emitting unit is connected to the ground voltage end; the two ends of the threshold compensation module are respectively connected to the second node and the third node; the reset module is used to reset the potential of the second node and the fourth node; the light-emitting control module is used to control the conduction between the first node and the power supply voltage end, and the conduction between the third node and the fourth node.

[0007] Optionally, the sensing control module includes a first active switch and a second active switch; the input end of the first active switch is connected to the power supply voltage end, and the output end of the first active switch is connected to the fifth node; the first storage module includes a first capacitor, one end of the first capacitor is connected to the power supply voltage end, and the other end of the first capacitor is connected to the fifth node; the input end of the second active switch is connected to the sensing unit, and the output end of the second active switch is connected to the fifth node; the data input module is connected to the fifth node.

[0008] Optionally, the light-emitting control module includes a third active switch and a fourth active switch, the input end of the third active switch is connected to the power supply voltage end, and the output end of the third active switch is connected to the first node; the input end of the fourth active switch is connected to the third node, and the output end of the fourth active switch is connected to the fourth node; the control end of the third active switch and the control end of the fourth active switch are respectively connected to the light-emitting control signal.

[0009] Optionally, the first active switch, the third active switch and the fourth active switch are respectively P-type active switches, and the second active switch is an N-type active switch; the control end of the first active switch and the control end of the second active switch are respectively connected to the light-emitting control signal; when the light-emitting control signal is a first level, the third active switch and the fourth active switch are turned on to make the light-emitting unit emit light, the second active switch is turned off, the sensing unit stops outputting the induced current to the first capacitor, and the first active switch is turned on to reset the fifth node; when the light-emitting control signal is a second level, the first active switch, the third active switch and the fourth active switch are turned off, the second active switch is turned on, and the sensing unit outputs the induced current to the first capacitor.

[0010] Optionally, the second storage module includes a second capacitor, one end of the second capacitor is connected to the power supply voltage terminal, and the other end of the second capacitor is connected to the second node; the data input module includes a fifth active switch, the input end of the fifth active switch is connected to the fifth node, and the output end of the fifth active switch is connected to the first node; the reset module includes a sixth active switch and a seventh active switch, the output end of the sixth active switch is connected to the second node, the input end of the sixth active switch is connected to the reference voltage terminal, the output end of the seventh active switch is connected to the fourth node, and the input end of the seventh active switch is connected to the reference voltage terminal; the threshold compensation module includes an eighth active switch, the input end of the eighth active switch is connected to the second node, and the output end of the eighth active switch is connected to the third node; the control end of the sixth active switch and the control end of the seventh active switch are respectively connected to the first scan control signal; the control end of the fifth active switch and the control end of the eighth active switch are respectively connected to the second scan control signal.

[0011] Optionally, when the light-emitting control signal is at the second level, the first scanning control signal and the second scanning control signal are in the first level state in sequence; the fifth active switch, the sixth active switch, the seventh active switch and the eighth active switch are respectively P-type active switches.

[0012] Optionally, the pixel driving circuit includes a detection and storage stage, a display reset stage, a data writing stage, and a light-emitting reset stage; in the detection and storage stage, the light-emitting control signal is in a second level state, and the first scan control signal and the second scan control signal are respectively in a second level state; in the display reset stage, the light-emitting control signal is in a second level state, the first scan control signal is in a first level state, and the second scan control signal is in a second level state; in the data writing stage, the light-emitting control signal is in a second level state, the first scan control signal is in a second level state, and the second scan control signal is in a first level state; in the light-emitting reset stage, the light-emitting control signal is in a first level state, the first scan control signal is in a second level state, and the second scan control signal is in a second level state.

[0013] Optionally, the sensing control module includes a first active switch; the input end of the first active switch is connected to the power supply voltage end, and the output end of the first active switch is connected to the fifth node; the first storage module includes a first capacitor, one end of the first capacitor is connected to the power supply voltage end, and the other end of the first capacitor is connected to the fifth node; the sensing unit includes a photosensitive active switch, the input end of the photosensitive active switch is connected to the preset voltage end, and the output end of the photosensitive active switch is connected to the fifth node; the data input module is connected to the fifth node.

[0014] The present application also discloses a display panel, comprising a base substrate and the above-mentioned pixel driving circuit, wherein the pixel driving circuit is arranged on the base substrate.

[0015] In the present application, the incident light is sensed by the sensing unit in the sensing drive circuit, and the light signal is converted into an induced current signal and stored in the first storage module. When the display drive circuit inputs data, the induced current signal stored in the first storage module is input into the display drive circuit as a data signal, and the display drive circuit displays according to the induced current signal. The present application deeply combines the sensing drive circuit and the display drive circuit so that sensing and display are performed step by step, thereby realizing the function of instant sensing and instant display. The present application does not require the setting of additional data signal lines, so that the induced current signal output by the sensing drive circuit directly enters the display drive circuit, thereby saving wiring space. Moreover, the detection results of the present application do not need to be processed by the detection processing module, sent to the system-level chip, and then displayed by the display drive circuit. This reduces system complexity, reduces material costs and power consumption, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without inventive work. In the drawings: Figure 1 is a schematic diagram of a pixel driving circuit according to a first embodiment of the present application; Figure 2 1 is a timing diagram of the pixel driving circuit of the first embodiment of the present application; Figure 3 is a schematic diagram of a pixel driving circuit according to a second embodiment of the present application; Figure 4 is a schematic diagram of a display panel of the present application; Figure 5Schematic diagram of a display panel with X-ray detection function of the present application.

[0017] Among them, 100, pixel driving circuit; 110, sensing driving circuit; 111, sensing unit; 111a, photosensor active switch; 112, first storage module; 113, sensing control module; 120, display driving circuit; 121, data input module; 122, light control module; 123, light unit; 124, second storage module; 125, reset module; 126, threshold compensation module; 200, display panel; 210, driving circuit board; 300, flat panel detection display; 310, scintillator layer; 320, pixel driving layer; 321, substrate; A, first Node; B, second node; D, third node; E, fourth node; F, fifth node; Q1, first driving transistor; T1, first active switch; T2, second active switch; T3, third active switch; T4, fourth active switch; T5, fifth active switch; T6, sixth active switch; T7, seventh active switch; T8, eighth active switch; C1, first capacitor; C2, second capacitor; VDD, power supply voltage terminal; VSS, ground voltage terminal; Vref, reference voltage terminal; Vref2, preset voltage terminal; S1, first scan control signal; S2, second scan control signal. DETAILED DESCRIPTION

[0018] It should be understood that the terms used herein, the specific structures and functional details disclosed are only for describing specific embodiments and are representative. However, the present application can be implemented in many alternative forms and should not be construed as being limited to the embodiments described herein.

[0019] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating relative importance or implicitly indicating the number of technical features indicated. Therefore, unless otherwise specified, features defined as "first" and "second" may explicitly or implicitly include one or more of such features; "multiple" means two or more. In addition, terms indicating orientation or positional relationships such as "upper", "lower", "left", "right", "vertical", and "horizontal" are described based on the orientation or relative positional relationships shown in the accompanying drawings. They are only simplified descriptions for the convenience of describing this application, and do not indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this application. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0020] The present application is described in detail below with reference to the accompanying drawings and optional embodiments.

[0021] Figure 1is a schematic diagram of a pixel driving circuit according to a first embodiment of the present application, Figure 2 is a timing diagram of the pixel driving circuit of the first embodiment of the present application; see Figures 1 to 2 As shown, the present application discloses a pixel driving circuit 100, a pixel driving circuit 100, which includes a display driving circuit 120 and a sensing driving circuit 110 in each pixel area; the sensing driving circuit 110 includes a sensing unit 111, a first storage module 112 and a sensing control module 113, the sensing unit 111 is used to generate an induced current after receiving target light, the first storage module 112 is used to store the induced current, and the sensing control module 113 is used to control the induced current to be stored in the first storage module 112; the display driving circuit 120 includes a data input module 121, a light control module 122 and a light unit 123, the data input module 121 is connected to the first storage module 112, and is used to receive the induced current from the storage module and input the induced current to the light control module 122 to drive the light unit 123 to display.

[0022] In the present application, the incident light is sensed by the sensing unit 111 in the sensing drive circuit 110, and the light signal is converted into an induced current signal, which is stored in the first storage module 112. When the display drive circuit 120 inputs data, the induced current signal stored in the first storage module 112 is input into the display drive circuit 120 as a data signal, and the display drive circuit 120 drives the light-emitting unit 123 to display according to the induced current signal. The present application deeply combines the sensing drive circuit 110 and the display drive circuit 120, so that sensing and display are performed step by step, realizing the function of instant sensing and instant display. The present application does not require the setting of additional data signal lines, so that the induced current signal output by the sensing drive circuit 110 directly enters the display drive circuit 120, thereby saving wiring space. Moreover, the detection results of the present application do not need to be processed by the detection processing module, sent to the system-level chip, and then displayed by the display drive circuit 120. This reduces system complexity, reduces material costs and power consumption, etc.

[0023] It is understood that for a typical display panel with a light-sensing function, the sensing driver circuit 110 needs to input the induced current into a detection processing module or a detection processing chip. After processing the induced current, the data signal corresponding to the induced current is input into the display driver circuit 120 again through the data driver chip of the display driver circuit 120, thereby realizing the sensing and display functions. However, the present application can adjust the correspondence between the induced current and the data signal so that when the induced current is different, the display driver circuit 120 can display the corresponding induced current.

[0024] Specifically, the pixel driving circuit 100 of the present application can be applied to similar image detection technologies such as flat panel detection display panels, by sensing the light emitted by the image and displaying it directly on the display panel. Specifically, it can be an X-ray flat panel detection display panel, which actively emits X-rays or uses X-rays emitted by other X-ray emitters to the detected object. The sensing unit 111 senses the X-rays or converts the X-rays into visible light and outputs an induced current. The display panel displays different images based on the induced current.

[0025] In one embodiment, the side of the sensing unit 111 that receives light (which can be called a photosensitive surface) and the side of the light-emitting unit 123 that emits light can be set to different surfaces (which can be called display surfaces), that is, the sensing surface and the display surface are the front and back of the display panel, respectively. Of course, the sensing surface and the display surface of the present application can also be set on the same side. The pixel driving circuit 100 of the present application can also be used in a display panel with a fingerprint recognition function or a face recognition function. It mainly utilizes the photosensitivity of the photosensitive unit to enable the fingerprint or face to be displayed directly through the display panel. It is a technology with a built-in sensing unit 111.

[0026] Specifically, the light-emitting unit 123 in the display driving circuit 120 is generally an organic light-emitting unit 123, and the sensing unit 111 of the present application can be a device such as a photodiode or a photosensitive thin film transistor that can convert a light signal into an electrical signal.

[0027] The sensing drive circuit 110 includes a sensing unit 111, a first storage module 112, and a sensing control module 113. In the sensing drive circuit 110, after the sensing unit 111 collects the light signal and converts it into an electrical signal, the sensing control module 113 is turned on, causing the first storage module 112 to store the electrical signal. The amount of electricity stored in the first storage module 112 is generally related to the on-time of the sensing control module 113. The amount of electricity in the first storage module 112 can be determined by controlling the on-time. By reasonably configuring the amount of electricity corresponding to different light intensities and matching this amount of electricity with the data signal used in the display drive circuit 120, display can be achieved based on the light intensity received by the sensing unit.

[0028] Specifically, the display driving circuit 120 also includes a second storage module 124, a reset module 125, a threshold compensation module 126 and a first driving transistor Q1; the data input module 121 is connected to the first node A, the input end of the first driving transistor Q1 is connected to the first node A, the control end of the driving transistor is connected to the second node B, and the output end of the driving transistor is connected to the third node D; one end of the second storage module 124 is connected to the power supply voltage terminal VDD, and the other end of the second storage module 124 is connected to the second node B; one end of the light-emitting unit 123 is connected to the fourth node E, and the other end of the light-emitting unit 123 is connected to the ground voltage terminal VSS; the two ends of the threshold compensation module 126 are respectively connected to the second node B and the third node D; the reset module 125 is used to reset the potential of the second node B and the fourth node E; the light-emitting control module 122 is used to control the conduction between the first node A and the power supply voltage terminal VDD, and the conduction between the third node D and the fourth node E.

[0029] The first node A is connected to the data input circuit and the input terminal of the first driving transistor Q1, the second node B is connected to the control terminal of the first driving transistor Q1, the third node D is connected to the output terminal of the first driving transistor Q1, and the fourth node E is connected to the anode terminal of the light emitting unit 123.

[0030] The display driver circuit 120 in this embodiment is primarily designed with functional modules such as a data input module 121, a second storage module 124, a reset module 125, and a light control module 122. After receiving the aforementioned induced current via the data input module 121, the second storage module 124 and the light control module 122 operate to cause the light-emitting unit 123 to display according to the magnitude of the induced current. For example, the greater the induced current, the higher the brightness of the light-emitting unit 123. The smaller the induced current, the lower the brightness of the light-emitting unit 123.

[0031] Of course, for a solution that uses an external compensation technology to compensate the threshold of the first driving transistor Q1 , the threshold compensation module 126 can also be removed, thereby using an external compensation circuit to achieve threshold compensation in the display driving circuit 120 .

[0032] Continue to see Figure 1As shown, the sensing control module 113 in this embodiment includes a first active switch T1 and a second active switch T2; the input end of the first active switch T1 is connected to the power supply voltage terminal VDD, and the output end of the first active switch T1 is connected to the fifth node F. The first storage module 112 includes a first capacitor C1, one end of the first capacitor C1 is connected to the power supply voltage terminal VDD, and the other end of the first capacitor C1 is connected to the fifth node F; the input end of the second active switch T2 is connected to the sensing unit 111, and the output end of the second active switch T2 is connected to the fifth node F; the data input module 121 is connected to the fifth node F.

[0033] Since one end of the first capacitor C1 is connected to the power supply voltage terminal VDD, it is always in the power supply voltage state during the different stages of sensing and display. Therefore, the voltage change of the first node A to which the other end of the first capacitor C1 is connected corresponds to the change in the amount of charge flowing into the induced current. The induced current of the sensing unit 111 is in the negative direction, that is, the positive charge flows from the fifth node F to the sensing unit 111. The induced current can be regarded as the voltage output from the fifth node F, and the voltage value of the fifth node F is set to Vse. When the light intensity is smaller, the induced current is smaller, and the corresponding Vse is larger. When Vse is larger, the brightness of the corresponding light-emitting unit 123 is higher. When the light intensity is greater, the induced current is larger, and the corresponding Vse is smaller. When Vse is smaller, the brightness of the corresponding light-emitting unit 123 is lower.

[0034] The first active switch T1 has a reset function. When the first active switch T1 is turned on, the two terminals of the first capacitor C1 are connected to the power supply voltage terminal VDD, so that the potential across the capacitor is configured as the power supply voltage potential. When the second active switch T2 is turned on, the first active switch T1 is in the off state. The voltage value of the first node A is discharged due to the conduction of the second active switch T2. The amount of discharge depends on the light intensity sensed by the photosensitive unit and the induced current. When the sensed light intensity is higher, the corresponding sensed current is greater, causing more discharge at the fifth node F of the first capacitor C1 and a corresponding decrease in Vse. Conversely, when the sensed light intensity is lower, the corresponding Vse is larger.

[0035] The sensing driving circuit 110 of the present application can be applied to a direct conversion flat panel detector or an indirect conversion flat panel detector. The basic principle is to combine a flash crystal coating or an amorphous selenium layer with a thin film transistor or an external bias electric field to enable the photosensitive unit to generate an induced current proportional to the light intensity. When the second active switch T2 is turned on, the data of the induced current is stored in the fifth node F of the first capacitor C1. Subsequently, there is a data input module 121 to read the voltage value on the fifth node F.

[0036] Specifically, the light control module 122 includes a third active switch T3 and a fourth active switch T4. The input end of the third active switch T3 is connected to the power supply voltage terminal VDD, and the output end of the third active switch T3 is connected to the first node A; the input end of the fourth active switch T4 is connected to the third node D, and the output end of the fourth active switch T4 is connected to the fourth node E; the control end of the third active switch T3 and the control end of the fourth active switch T4 are respectively connected to the light control signal.

[0037] The light-emission control signal drives the third active switch T3 and the fourth active switch T4 on and off, controlling whether the light-emitting unit 123 is connected to the power supply voltage terminal VDD and the ground voltage terminal VSS, thereby controlling whether the light-emitting unit 123 emits light. The current flowing through the light-emitting unit 123 is regulated based on the gate voltage of the first drive transistor Q1 to achieve different grayscale brightness displays. Before data is written to the light-emitting unit 123, the light-emission control signal is used to disable the light-emitting unit 123 to avoid displaying incorrect brightness.

[0038] In this embodiment, since sensing and luminescence need to be performed in time periods, that is, sensing is completed first and then display is performed. The third active switch T3 and the fourth active switch T4 mainly control whether the light-emitting unit 123 emits light. When the third active switch T3 and the fourth active switch T4 are turned off, the light-emitting unit 123 does not emit light. At this time, the photosensitive unit receives light and stores the induced current in the first capacitor C1. When the third active switch T3 and the fourth active switch T4 are turned on, the light-emitting unit 123 emits light. At this time, the photosensitive unit receives light but does not transmit the induced current to the first capacitor C1. Among them, after the third active switch T3 and the fourth active switch T4 are turned on, they also need to cooperate with the data input circuit, the reset module 125 and the threshold compensation module 126 to make the third active switch T3 and the fourth active switch T4 drive the light-emitting unit 123 to emit light.

[0039] In one embodiment, the control terminals of the first active switch T1, the second active switch T2, the third active switch T3, and the fourth active switch T4 are each connected to the light-emission control signal. The first active switch T1, the third active switch T3, and the fourth active switch T4 are each P-type active switches, and the second active switch T2 is an N-type active switch. The first driving transistor Q1 of the present application is a P-type thin-film transistor.

[0040] When the light-emitting control signal is at a first level, the third active switch T3 and the fourth active switch T4 are turned on to enable the light-emitting unit 123 to emit light, the second active switch T2 is turned off, the sensing unit 111 stops outputting the induced current to the first capacitor C1, and the first active switch T1 is turned on to reset the fifth node F. When the light-emitting control signal is at a second level, the first active switch T1, the third active switch T3, and the fourth active switch T4 are turned off, the second active switch T2 is turned on, and the sensing unit 111 outputs the induced current to the first capacitor C1.

[0041] The first level is generally a logic low signal, which is used to turn off the N-type active switch and turn on the P-type active switch. The second level is generally a logic high signal, which is used to turn on the N-type active switch and turn off the P-type active switch. The N-type active switch can use a-Si or oxide semiconductor as the active switch active layer. The P-type active switch mainly uses the LTPS process.

[0042] In this embodiment, the sensing period and the light-emitting period are adjusted by a light-emission control signal. Only one control signal is required to control the first active switch T1 and the second active switch T2 in the sensing drive circuit 110. By configuring the first active switch T1 and the second active switch T2 as different types of active switches, the reset and readout of the photosensitive unit can be achieved.

[0043] Specifically, the display driver circuit 120 of the present application can be illustrated by a 7T1C circuit, but this does not mean that the display driver circuit 120 of the present application is limited to the 7T1C circuit design. Other display driver circuits 120 that drive the light-emitting unit 123 and are suitable for circuit designs of light-emitting control signals also fall within the scope of protection of the present application.

[0044] Specifically, the second storage module 124 includes a second capacitor C2, one end of which is connected to the power supply voltage terminal VDD, and the other end of which is connected to the second node B. The data input module 121 includes a fifth active switch T5, an input end of which is connected to the fifth node F, and an output end of which is connected to the first node A. The reset module 125 includes a sixth active switch T6 and a seventh active switch T7, an output end of which is connected to the second node B, an input end of which is connected to the reference voltage terminal Vref, an output end of which is connected to the fourth node E, and an input end of which is connected to the reference voltage terminal Vref. The threshold compensation module 126 includes an eighth active switch T8, wherein the input end of the eighth active switch T8 is connected to the second node B, and the output end of the eighth active switch T8 is connected to the third node D; the control end of the sixth active switch T6 and the control end of the seventh active switch T7 are respectively connected to the first scan control signal S1; the control end of the fifth active switch T5 and the control end of the eighth active switch T8 are respectively connected to the second scan control signal S2.

[0045] Among them, the fifth active switch T5, the sixth active switch T6, the seventh active switch T7, and the eighth active switch T8 of the present application are respectively P-type active switches, which are turned on at a logic low level and turned off at a logic high level. The first scan control signal S1 and the second scan control signal S2 are row scan drive signals, and only one logic low level pulse appears within a frame time. When the first scan control signal S1 is at a logic low level, the sixth active switch T6 and the seventh active switch T7 are turned on, thereby resetting the potential of the second node B and the potential of the fourth node E, that is, controlling the gate of the first driving transistor Q1 and the anode of the light-emitting unit 123 to reset. When the second scan control signal S2 is at a logic low level, the fifth active switch T5 is turned on, allowing the induced current to be written. And the eighth active switch T8 is turned on, so that the second node B is electrically connected to the third node D, achieving threshold compensation of the first driving transistor Q1.

[0046] When the light-emitting control signal is at the second level, the first scan control signal S1 and the second scan control signal S2 are sequentially at the first level. The first scan control signal S1 and the second scan control signal S2 are typically provided by different gate drive units in the same gate drive circuit and have equal pulse widths. Furthermore, the first scan control signal S1 and the second scan control signal S2 are sequentially turned on and off, and a certain interval is set between the first scan control signal S1 and the second scan control signal S2, so that data writing time is allocated for each row of light-emitting units 123.

[0047] The power supply voltage terminal VDD outputs a power supply voltage signal, providing a positive voltage signal to the light-emitting unit 123. The power supply voltage signal generally enters the anode terminal of the light-emitting unit 123 and controls the current entering the light-emitting unit 123 through the data signal, thereby controlling the brightness of the light-emitting unit 123. The cathode terminal of the light-emitting unit 123 is generally connected to the ground voltage terminal VSS, which provides a ground voltage signal to the light-emitting unit 123. The reference voltage terminal Vref generally inputs a reference voltage signal for resetting the anode terminal of the light-emitting unit 123 and the gate terminal of the first driving transistor Q1.

[0048] Specifically, the pixel driving circuit 100 includes a detection and storage phase, a display reset phase, a data writing phase, and a light emitting reset phase.

[0049] During the detection and storage phase, the light-emission control signal is at the second level, and the first and second scanning control signals S1 and S2 are both at the second level. At this point, the second active switch T2 is turned on, and the photosensitive unit discharges, causing the Vse of the fifth node F to change, and a voltage corresponding to the light intensity is stored in the fifth node F.

[0050] In the display reset phase, the light emitting control signal is in a second level state, the first scanning control signal S1 is in a first level state, and the second scanning control signal S2 is in a second level state. At this time, the second active switch T2 still remains in the on state, so that the photosensitive unit continues to discharge, and the sum of the time of the corresponding detection storage phase and the display reset phase is the photosensitive detection duration. The photosensitive detection duration can be controlled by reasonably setting the duration of the two, especially the duration of the detection storage phase. Relatively speaking, the longer the photosensitive detection duration, the longer the corresponding detection time and the higher the detection accuracy. In the display reset phase, the first scanning control signal S1 is in a first level state, so that during the sensing process of the sensing drive circuit 110, the potential of the second node B and the potential of the fourth node E are also reset synchronously, preparing for the writing of the data signal.

[0051] During the data write phase, the light-emitting control signal is at a second level, the first scan control signal S1 is at a second level, and the second scan control signal S2 is at a first level. When the second scan control signal S2 is at the first level, the first drive transistor Q1, the fifth active switch T5, and the eighth active switch T8 are simultaneously turned on, passing Vse through the path formed by the fifth active switch T5, the first drive transistor Q1, and the eighth active switch T8, thereby writing Vse into the gate of the first drive transistor Q1 and performing threshold compensation. A certain time interval can also be reserved between the data write phase and the display reset phase to increase the detection time. When entering the data write phase, the sensing unit no longer writes.

[0052] During the light-reset phase, the light-emission control signal is at a first level, the first scan control signal S1 is at a second level, and the second scan control signal S2 is at a second level. After the light-emission control signal is at the first level, the first active switch T1 in the sensing drive circuit 110 is turned on, resetting the potential of the fifth node F. The second active switch T2 is turned off, and the sensing unit 111 no longer reads the sensed current, waiting for the next frame detection and storage phase to begin. The second scan control signal S2 is at a second level, and both the fifth active switch T5 and the eighth active switch T8 are turned off. Vse stored in the second capacitor C2 controls the gate of the first drive transistor Q1 to drive the light-emitting unit 123 to display.

[0053] Specifically, when Vse at the fifth node F is lower, the gate voltage written to the first driver transistor Q1 is lower, and the absolute value of the gate-source voltage Vgs (Vgs = Vg_Q1 - VDD) of the first driver transistor Q1 is larger. Vg_Q1 represents the gate voltage of the first driver transistor Q1. Taking the voltage of the fifth node F as Vse as an example, according to the compensation principle of the display driver circuit 120 of the present application, the gate voltage Vg_Q1 written to the first driver transistor Q1 is Vse + Vth. According to the current formula: Substituting Vgs=Vse+Vth-VDD, we get: . Where μ p is the electron mobility, C ox is the unit area capacitance of the TFT device, and W / L represents the ratio of the TFT channel width to the length. According to the formula, when Vse is smaller, the corresponding current I output by the first driving transistor Q1 is d The larger the value is, the higher the brightness of the corresponding light emitting unit 123 is, thereby realizing the sensing structure instant display function.

[0054] Figure 3 is a schematic diagram of a pixel driving circuit according to the second embodiment of the present application, see Figure 3As shown, the present application also discloses another pixel driving circuit. The main design of the pixel driving circuit 100 is the same as that of the first embodiment, and will not be repeated here. The difference is that the photosensitive unit is replaced by a second active switch T2, thereby removing the design of the photosensitive diode.

[0055] Specifically, the sensing unit 111 includes a light-sensitive active switch 111a, the input of which is connected to a preset voltage terminal Vref2, and the output of which is connected to the fifth node F; the data input module 121 is connected to the fifth node F. The preset voltage terminal Vref2 can simply emit a low-voltage reference signal, which can be adjusted according to actual conditions or serve as a compensation signal input terminal. For example, when the light-sensitive thin-film transistor is not sensitive enough to light, or when the voltage at the fifth node is not fully released, the voltage value of the low-voltage reference signal can be changed to compensate for the induced current as a data signal.

[0056] In this embodiment, sensing unit 111 utilizes a photosensitive thin-film transistor. The active layer channel formed of a-Si or oxide semiconductor within the photosensitive thin-film transistor is sensitive to light. Light intensity sensing is achieved by utilizing the different leakage currents of the photosensitive thin-film transistor under different light intensities. As light intensity increases, the current of the photosensitive active switch 111a increases, causing the voltage Vse to decrease. Consequently, higher light brightness corresponds to higher brightness of the corresponding light-emitting unit 123.

[0057] Figure 4 is a schematic diagram of the display panel of this application, see Figure 4 As shown, the present application also discloses a display panel, and the display panel 200 includes a base substrate and a pixel driving circuit 100 in any one of the above embodiments, and the pixel driving circuit 100 is arranged on the base substrate. Of course, the display panel also includes a packaging layer, a color filter layer and other film layers arranged on the base substrate. The pixel driving circuit 100 drives the light-emitting unit 123 to work, and the light-emitting unit 123 emits light from the packaging layer and the color filter layer for display. At the same time, the pixel driving circuit 100 is also externally connected to a driving circuit board 210, and the driving circuit board 210 is provided with chips such as a timing controller and a sensing controller to drive the pixel driving circuit 100 to sense the target light and display the picture. It can be understood that the sensing unit 111 of the display panel can be used for light control or light detection such as fingerprint recognition and air touch.

[0058] Figure 5 This is a schematic diagram of a display panel with an X-ray detection function of the present application, see Figure 5As shown, the present application also discloses a display panel with an X-ray detection function, which can also be called a flat panel detection display. The flat panel detection display 300 includes a scintillator layer 310 and a pixel driving layer 320. The scintillator layer is used to convert X-rays into visible light. The pixel driving layer 320 includes a base substrate 321 and a plurality of pixel driving circuits 100 such as any of the above embodiments disposed on the base substrate 321. The pixel driving layer 320 includes a plurality of pixel areas arranged in an array, each of which is provided with a pixel driving circuit 100; and each of the pixel areas is provided with a light-emitting unit 123 and a sensing unit 111, and the light-emitting unit 123 is provided on the same layer as the sensing unit 111. The flat panel detection display combines a flat panel detector with a display so that image information detected by the flat panel detector is directly displayed on the display.

[0059] It should be noted that the inventive concept of this application can form a large number of embodiments, but the length of the application document is limited and it is impossible to list them one by one. Therefore, under the premise of no conflict, the various embodiments or technical features described above can be arbitrarily combined to form new embodiments. After the various embodiments or technical features are combined, the original technical effects will be enhanced.

[0060] The above content is a further detailed description of the present application in conjunction with specific optional implementation methods, and the specific implementation of the present application cannot be considered to be limited to these descriptions. For ordinary technicians in the technical field to which the present application belongs, they can make several simple deductions or substitutions without departing from the concept of the present application, which should be considered to fall within the scope of protection of the present application.

Claims

1. A pixel driving circuit, characterized in that: Each pixel area includes a display driving circuit and a sensing driving circuit; The sensing driving circuit includes a sensing unit, a first storage module, and a sensing control module. The sensing unit is used to generate a sensing current after receiving target light. The first storage module is used to store the sensing current. The sensing control module is used to control the storage of the sensing current in the first storage module. The display driving circuit includes a data input module, a light-emitting control module and a light-emitting unit. The data input module is connected to the first storage module, and is used to receive the induced current from the storage module and input the induced current to the light-emitting control module to drive the light-emitting unit to display.

2. The pixel driving circuit according to claim 1, wherein: The display driving circuit further includes a second storage module, a reset module, a threshold compensation module and a first driving transistor; The data input module is connected to a first node, the input terminal of the first driving transistor is connected to the first node, the control terminal of the driving transistor is connected to a second node, and the output terminal of the driving transistor is connected to a third node; One end of the second storage module is connected to the power supply voltage terminal, and the other end of the second storage module is connected to the second node; One end of the light emitting unit is connected to the fourth node, and the other end of the light emitting unit is connected to the ground voltage terminal; Two ends of the threshold compensation module are connected to the second node and the third node respectively; The reset module is used to reset the potentials of the second node and the fourth node; The light emitting control module is used to control the conduction between the first node and the power supply voltage terminal, and the conduction between the third node and the fourth node.

3. The pixel driving circuit according to claim 2, wherein: The sensing control module includes a first active switch and a second active switch; the input end of the first active switch is connected to the power supply voltage end, and the output end of the first active switch is connected to the fifth node; The first storage module includes a first capacitor, one end of the first capacitor is connected to the power supply voltage terminal, and the other end of the first capacitor is connected to the fifth node; An input terminal of the second active switch is connected to the sensing unit, and an output terminal of the second active switch is connected to the fifth node; The data input module is connected to the fifth node.

4. The pixel driving circuit according to claim 3, wherein: The light emitting control module includes a third active switch and a fourth active switch, the input end of the third active switch is connected to the power supply voltage end, and the output end of the third active switch is connected to the first node; An input terminal of the fourth active switch is connected to the third node, and an output terminal of the fourth active switch is connected to the fourth node; The control end of the third active switch and the control end of the fourth active switch are respectively connected to the light emitting control signal.

5. The pixel driving circuit according to claim 4, wherein: The first active switch, the third active switch and the fourth active switch are respectively P-type active switches, and the second active switch is an N-type active switch; The control end of the first active switch and the control end of the second active switch are respectively connected to the light emitting control signal; When the light-emitting control signal is at the first level, the third active switch and the fourth active switch are turned on to make the light-emitting unit emit light, the second active switch is turned off, the sensing unit stops outputting the sensed current to the first capacitor, and the first active switch is turned on to reset the fifth node; When the light emitting control signal is at the second level, the first active switch, the third active switch, and the fourth active switch are turned off, the second active switch is turned on, and the sensing unit outputs the induced current to the first capacitor.

6. The pixel driving circuit according to claim 5, wherein: The second storage module includes a second capacitor, one end of the second capacitor is connected to the power supply voltage terminal, and the other end of the second capacitor is connected to the second node; The data input module includes a fifth active switch, wherein the input end of the fifth active switch is connected to the fifth node, and the output end of the fifth active switch is connected to the first node; The reset module includes a sixth active switch and a seventh active switch, wherein the output end of the sixth active switch is connected to the second node, the input end of the sixth active switch is connected to the reference voltage end, the output end of the seventh active switch is connected to the fourth node, and the input end of the seventh active switch is connected to the reference voltage end; The threshold compensation module includes an eighth active switch, wherein the input end of the eighth active switch is connected to the second node, and the output end of the eighth active switch is connected to the third node; The control end of the sixth active switch and the control end of the seventh active switch are respectively connected to the first scan control signal; The control end of the fifth active switch and the control end of the eighth active switch are respectively connected to the second scan control signal.

7. The pixel driving circuit according to claim 6, wherein: When the light emitting control signal is at the second level, the first scanning control signal and the second scanning control signal are sequentially at the first level state; The fifth active switch, the sixth active switch, the seventh active switch, and the eighth active switch are P-type active switches respectively.

8. The pixel driving circuit according to claim 6, wherein: The pixel driving circuit includes a detection and storage stage, a display reset stage, a data writing stage, and a light emitting reset stage; In the detection and storage phase, the light emitting control signal is in a second level state, and the first scanning control signal and the second scanning control signal are respectively in a second level state; In the display reset phase, the light emitting control signal is in a second level state, the first scanning control signal is in a first level state, and the second scanning control signal is in a second level state; In the data writing phase, the light emitting control signal is in a second level state, the first scanning control signal is in a second level state, and the second scanning control signal is in a first level state; In the light-emitting reset phase, the light-emitting control signal is in a first level state, the first scanning control signal is in a second level state, and the second scanning control signal is in a second level state.

9. The pixel driving circuit according to claim 2, wherein: The sensing control module includes a first active switch; an input terminal of the first active switch is connected to the power supply voltage terminal, and an output terminal of the first active switch is connected to a fifth node; The first storage module includes a first capacitor, one end of the first capacitor is connected to the power supply voltage terminal, and the other end of the first capacitor is connected to the fifth node; The sensing unit includes a light-sensitive active switch, wherein the input end of the light-sensitive active switch is connected to the preset voltage end, and the output end of the light-sensitive active switch is connected to the fifth node; The data input module is connected to the fifth node.

10. A display panel, characterized in that: The invention comprises a base substrate and a pixel driving circuit according to any one of claims 1 to 9, wherein the pixel driving circuit is arranged on the base substrate.

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