Pixel driving circuit, display device and display screen bright spot repairing method

Abstract

The present disclosure provides a pixel driving circuit, a display device and a display screen bright spot repair method, belonging to the technical field of display, which can solve the problem that the existing display screen is prone to bright spot defects. The pixel driving circuit comprises: an initialization sub-circuit configured to initialize the voltage of a first node by using a first initialization signal in response to a reset signal; a data writing sub-circuit configured to write a data signal to the first node in response to a scanning signal; a light emitting control sub-circuit configured to provide a driving voltage to a first electrode of a light emitting device in response to a light emitting control signal; and a voltage compensation sub-circuit configured to compensate the voltage of the first node by using a compensation voltage in response to a switching signal.

Description

Technical Field

[0001] This disclosure belongs to the field of display technology, specifically relating to a pixel driving circuit, a display device, and a method for repairing bright spots in a display screen. Background Technology

[0002] Organic light-emitting diodes (OLEDs) are light-emitting devices that use organic solid-state semiconductors as light-emitting materials. Due to their advantages such as simple fabrication process, low cost, low power consumption, high brightness, and wide operating temperature range, they have broad application prospects.

[0003] Currently, the incidence of bright spot defects in OLED display products is 30%. The usual method to repair bright spot defects is to disconnect the pixel driving circuit at the bright spot, causing the light-emitting device at that location to stop emitting light and preventing the defect from occurring. However, while this eliminates the bright spot defect, it increases dark spots in the displayed image, which no longer meets users' display requirements. Summary of the Invention

[0004] This disclosure aims to at least solve one of the technical problems existing in the prior art, and provides a pixel driving circuit, a display device, and a method for repairing bright spots in the display screen.

[0005] In a first aspect, embodiments of this disclosure provide a pixel driving circuit, the pixel driving circuit comprising: an initialization sub-circuit, a driving transistor, a first storage capacitor, a data writing sub-circuit, a light emission control sub-circuit, and a voltage compensation sub-circuit;

[0006] The initialization sub-circuit is configured to initialize the voltage of the first node using a first initialization signal in response to a reset signal, and is also configured to initialize the voltage of the first electrode of the light-emitting device using a second initialization signal in response to a reset signal; the first node is the connection point between the initialization sub-circuit, the control electrode of the driving transistor, and the first storage capacitor.

[0007] The first storage capacitor is configured to store the voltage of the first node;

[0008] The data writing sub-circuit is configured to write a data signal to the first node in response to a scan signal, and is also configured to write the threshold voltage of the driving transistor to the first node.

[0009] The light emission control sub-circuit is configured to provide a driving voltage to the first electrode of the light emission device in response to a light emission control signal;

[0010] The voltage compensation sub-circuit is configured to compensate the voltage of the first node using a compensation voltage in response to a switching signal.

[0011] Optionally, the initialization sub-circuit includes: a first transistor; the control electrode of the first transistor is connected to a reset signal terminal, the first electrode is connected to a first initialization signal terminal, and the second electrode is connected to a first node;

[0012] The initialization sub-circuit further includes: a seventh transistor, wherein the control electrode of the seventh transistor is connected to the reset signal terminal, the first electrode is connected to the second initialization signal terminal, and the second electrode is connected to the first electrode of the light-emitting device.

[0013] Optionally, the data writing sub-circuit includes: a fourth transistor;

[0014] The control electrode of the fourth transistor is connected to the scan signal terminal, the first electrode is connected to the data signal terminal, and the second electrode is connected to the first electrode of the driving transistor.

[0015] The data writing sub-circuit further includes: a second transistor; the control electrode of the second transistor is connected to the scan signal terminal, the first electrode is connected to the second electrode of the driving transistor, and the second electrode is connected to the first node.

[0016] Optionally, the light-emitting control sub-circuit includes: a fifth transistor and / or a sixth transistor;

[0017] The control electrode of the fifth transistor is connected to the light-emitting control signal terminal, the first electrode is connected to the first power supply voltage terminal, and the second electrode is connected to the first electrode of the driving transistor.

[0018] The control electrode of the sixth transistor is connected to the light-emitting control signal terminal, the first electrode is connected to the second electrode of the driving transistor, and the second electrode is connected to the first electrode of the light-emitting device.

[0019] Optionally, the voltage compensation sub-circuit includes: a second storage capacitor and an eighth transistor;

[0020] One end of the second storage capacitor is connected to the switch signal terminal, and the other end is connected to the control electrode of the eighth transistor;

[0021] The control electrode of the eighth transistor is connected to the other end of the second storage capacitor, the first electrode is connected to the compensation voltage terminal, and the second electrode is connected to the first node.

[0022] The control electrode and the first electrode of the eighth transistor are electrically connected by a jumper wire.

[0023] Secondly, embodiments of this disclosure provide a display device, the display device including the pixel driving circuit as described above.

[0024] Optionally, the display device further includes: a plurality of first shift registers, a plurality of second shift registers, and a plurality of third shift registers;

[0025] The output of each of the first shift registers is connected to the scan signal terminal of the pixel driving circuit of the corresponding row;

[0026] The output of each of the second shift registers is connected to the light emission control signal terminal of the pixel driving circuit in the corresponding row;

[0027] The output of each of the third shift registers is connected to the switch signal terminal in the pixel driving circuit of the corresponding row.

[0028] Thirdly, embodiments of this disclosure provide a method for repairing bright spots in a display screen, employing the pixel driving circuit provided above. The method for repairing bright spots in a display screen includes:

[0029] According to the preset timing sequence, the pixel driving circuits of each row are scanned to display the preset display screen;

[0030] If a bright spot appears in the preset display screen, in response to the switch signal, the voltage of the first node in the pixel driving circuit at the bright spot is compensated using a compensation voltage.

[0031] Optionally, the step of compensating the voltage of the first node in the pixel driving circuit at the bright spot using a compensation voltage in response to a switching signal includes:

[0032] Cut off the shorting wire between the control electrode and the first electrode of the eighth transistor in the pixel driving circuit at the bright spot;

[0033] The switching signal at the corresponding row's switching signal terminal is converted from a non-operating level to an operating level, causing the eighth transistor to turn on, so as to input the compensation voltage to the first node.

[0034] Optionally, a laser can be used to cut off the shorting wire between the control electrode and the first electrode of the eighth transistor in the pixel driving circuit at the bright spot. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of an exemplary pixel driving circuit.

[0036] Figure 2 for Figure 1 The timing diagram of the pixel driving circuit is shown.

[0037] Figure 3 This is a schematic diagram of a pixel driving circuit provided in an embodiment of the present disclosure.

[0038] Figure 4 for Figure 3 The timing diagram of the pixel driving circuit is shown.

[0039] Figure 5 This is a flowchart illustrating a method for repairing bright spots in a display screen, as provided in an embodiment of this disclosure. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an,” “a,” or “the,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “including,” “comprising,” or “containing,” and similar terms mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. The terms “connected,” “linked,” or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0042] The transistors used in the embodiments of this disclosure can all be thin-film transistors, field-effect transistors, or other devices with the same characteristics. In this embodiment, the coupling method of the drain and source of each transistor can be interchanged; therefore, the drain and source of each transistor in this disclosure embodiment are actually indistinguishable. Here, one of the two terminals of the transistor, excluding the control terminal (i.e., the gate), is called the drain, and the other is called the source. The thin-film transistors used in the embodiments of this disclosure can be N-type transistors or P-type transistors. In the embodiments of this disclosure, when an N-type thin-film transistor is used, its first terminal can be the source, and its second terminal can be the drain. In the following embodiments, the description uses an N-type thin-film transistor as an example.

[0043] In this embodiment, a working level signal refers to a signal that, when input to the control electrode of a transistor, can control the transistor to conduct, while a non-working level signal refers to a signal that, when input to the control electrode of a transistor, can control the transistor to turn off. For N-type transistors, a high-level signal is a working level signal, and a low-level signal is a non-working level signal; for P-type transistors, the opposite is true.

[0044] Figure 1 This is a schematic diagram of an exemplary pixel driving circuit, such as... Figure 1 As shown, the pixel driving circuit includes: an initialization sub-circuit 101, a driving transistor T3, a first storage capacitor C1, a data writing sub-circuit 102, and a light emission control sub-circuit 103.

[0045] The initialization sub-circuit 101 includes: a first transistor T1; the gate of the first transistor T1 is connected to the reset signal terminal Reset, the source is connected to the first initialization signal terminal Vint1, and the drain is connected to the first node N1; the first node N1 is the connection point between the initialization sub-circuit 101, the gate of the driving transistor T3, the first storage capacitor C1, and the data writing sub-circuit 102. The initialization sub-circuit 101 also includes: a seventh transistor T7; the gate of the seventh transistor T7 is connected to the reset signal terminal Reset, the source is connected to the second initialization signal terminal Vint2, and the drain is connected to the first electrode (anode) of the light-emitting device D1.

[0046] The data writing sub-circuit 102 includes: a fourth transistor T4; the gate of the fourth transistor T4 is connected to the scan signal terminal Gate, the source is connected to the data signal terminal Data, and the drain is connected to the source of the driving transistor T3. The data writing sub-circuit 102 also includes: a second transistor T2; the gate of the second transistor T2 is connected to the scan signal terminal Gate, the source is connected to the drain of the driving transistor T3, and the drain is connected to the first node N1.

[0047] The light-emitting control sub-circuit 103 includes: a fifth transistor T5 and / or a sixth transistor T6; the gate of the fifth transistor T5 is connected to the light-emitting control signal terminal EM, the source is connected to the first power supply voltage terminal VDD, and the drain is connected to the source of the driving transistor T3; the gate of the sixth transistor T6 is connected to the light-emitting control signal terminal EM, the source is connected to the drain of the driving transistor T3, and the drain is connected to the first electrode (anode) of the light-emitting device D1.

[0048] One end of the first storage capacitor C1 is connected to the first node N1, and the other end is connected to the first power supply voltage terminal VDD. The first electrode (anode) of the light-emitting device D1 is connected to the drain of the sixth transistor T6 and the drain of the seventh transistor T7, and the second electrode (cathode) is connected to the second power supply voltage terminal VSS. The first power supply voltage terminal VDD is a high-level voltage terminal, and the second power supply voltage terminal VSS is a low-level voltage terminal.

[0049] Figure 2 for Figure 1 The timing diagram of the pixel driving circuit shown below will be combined with... Figure 2 The timing diagram shown is for Figure 1 The operation of the pixel driving circuit shown will be described in further detail.

[0050] In the first stage, a low-level signal is input to the Reset signal terminal, and the first transistor T1 and the seventh transistor T7 are turned on. The first initialization signal is input to the first node N1 through the first transistor T1, and the second initialization signal is input to the anode of the light-emitting device D1 through the seventh transistor T7, so as to initialize the voltage of the first node N1 and the voltage of the anode of the light-emitting device D1, and prevent the voltage input of the previous frame of display from affecting the current display.

[0051] In the second stage, a low-level signal is input to the scan signal terminal (Gate), turning on the second transistor T2 and the fourth transistor T4. The gate and drain of the driving transistor T3 are shorted by the second transistor T2, allowing the threshold voltage of the driving transistor T3 to be read and input to the first node N1 along with the data signal, thus realizing the input of the data signal and threshold voltage compensation. The first storage capacitor C1 can store the voltage of the first node N1.

[0052] In the third stage, a low-level signal is input to the light-emitting control signal terminal EM, and the fifth transistor T5 and the sixth transistor T6 are turned on. The first power supply voltage terminal VDD and the second power supply voltage terminal VSS form a current loop through the light-emitting device D1, which can provide driving current for the light-emitting device D1, so that the light-emitting device D1 emits light. The brightness of the light-emitting device D1 can be adjusted by controlling the gray level voltage of the data signal to adjust the turn-on degree of the driving transistor T3.

[0053] However, the first transistor T1 and the second transistor T2 in the pixel driving circuit are prone to leakage during use. This causes the first node N1 to leak through the first transistor T1 to the first initialization signal terminal Vint1, or through the second transistor T2 to the second power supply voltage terminal VSS. As a result, the voltage of the first node N1 becomes negatively biased, and the driving transistor T3 is in a partially turned-on state, causing poor pixel quality.

[0054] To at least solve one of the aforementioned technical problems, this disclosure provides a pixel driving circuit, a display device, and a method for repairing bright spots in a display screen. The following will describe in further detail the pixel driving circuit, display device, and method for repairing bright spots in a display screen provided by this disclosure in conjunction with the accompanying drawings and specific embodiments.

[0055] In a first aspect, embodiments of this disclosure provide a pixel driving circuit. Figure 3 This is a schematic diagram of a pixel driving circuit provided in an embodiment of the present disclosure, such as... Figure 3 As shown, the pixel driving circuit includes: an initialization sub-circuit 101, a driving transistor T3, a first storage capacitor C1, a data writing sub-circuit 102, a light emission control sub-circuit 103, and a voltage compensation sub-circuit 104.

[0056] The initialization sub-circuit 101 is configured to initialize the voltage of the first node N1 using a first initialization signal in response to a reset signal. The initialization sub-circuit 101 is also configured to initialize the voltage of the first electrode of the light-emitting device D1 using a second initialization signal in response to a reset signal. The first node N1 is the connection point between the initialization sub-circuit 101, the gate of the driving transistor T3, and the first storage capacitor C1. Alternatively, the first node N1 can also be the connection point between the initialization sub-circuit 101, the gate of the driving transistor T3, the first storage capacitor C1, and the data writing sub-circuit 102. The first storage capacitor C1 is configured to store the voltage of the first node N1. The data writing sub-circuit 102 is configured to write a data signal to the first node N1 in response to a scan signal. Alternatively, the data writing sub-circuit 102 can also be configured to write the data signal and the threshold voltage of the driving transistor T3 to the first node N1 in response to a scan signal. The light emission control sub-circuit 103 is configured to provide a driving voltage to the first electrode of the light-emitting device D1 in response to a light emission control signal. The voltage compensation sub-circuit 104 is configured to compensate the voltage of the first node N1 in response to a switching signal using a compensation voltage. For example, if the data signal Vdata at point N1 is leaked to the first initialization signal terminal Vint1, there will be a negative voltage drop ΔV. This ΔV is compensated back by the voltage at the compensation voltage terminal Vrw through the voltage compensation sub-circuit 104.

[0057] In the pixel driving circuit provided in this embodiment, when the display screen is displayed normally, the voltage compensation sub-circuit 104 is in a non-operating state. The initialization sub-circuit 101, driving transistor T3, first storage capacitor C1, data writing sub-circuit 102, and light emission control sub-circuit 103 operate normally to achieve normal display function. At this time, it can be considered that the voltage compensation sub-circuit 104 responds to the switching signal, and the compensation voltage input to the first node is 0. When a bright spot appears in the display screen, under the control of the switching signal, the voltage compensation sub-circuit 104 is in an operating state, and can input the compensation voltage to the first node N1 to compensate the voltage of the first node N1, so that the voltage of the first node N1 reaches the preset voltage, avoiding voltage leakage at the first node N1, thereby repairing the bright spot in the display screen. Simultaneously, the display brightness at this point is the same as the surrounding display brightness, preventing dark spots and improving the display effect to meet user needs. Specifically, the initialization sub-circuit 101 includes: a first transistor T1, the gate of which is connected to the reset signal terminal Reset, the source of which is connected to the first initialization signal terminal Vint1, and the drain of which is connected to the first node N1. The initialization sub-circuit 101 may also include: a seventh transistor T7; the gate of the first transistor T1 is connected to the reset signal terminal Reset, the source of which is connected to the first initialization signal terminal Vint1, and the drain of which is connected to the first node N1; the first node N1 is the connection point between the initialization sub-circuit 101, the gate of the driving transistor T3, the first storage capacitor C1, and the data writing sub-circuit 102. The gate of the seventh transistor T7 is connected to the reset signal terminal Reset, the source of which is connected to the second initialization signal terminal Vint2, and the drain of which is connected to the first electrode (anode) of the light-emitting device D1.

[0058] The data writing sub-circuit 102 includes a fourth transistor T4, whose gate is connected to the scan signal terminal Gate, its source is connected to the data signal terminal Data, and its drain is connected to the source of the driving transistor T3. Of course, the fourth transistor T4 can also be configured in other ways. For example, the data writing sub-circuit 102 includes a fourth transistor T4, whose gate is connected to the scan signal terminal Gate, its source is connected to the data signal terminal Data, and its drain is connected to the gate of the driving transistor T3.

[0059] Optionally, the data writing sub-circuit 102 may further include a second transistor T2. For example, the data writing sub-circuit 102 includes a second transistor T2 and a fourth transistor T4; the gate of the second transistor T2 is connected to the scan signal terminal Gate, the source is connected to the drain of the driving transistor T3, and the drain is connected to the first node N1; the gate of the fourth transistor T4 is connected to the scan signal terminal Gate, the source is connected to the data signal terminal Data, and the drain is connected to the source of the driving transistor T3.

[0060] The light-emitting control sub-circuit 103 includes: a fifth transistor T5 and / or a sixth transistor T6; the gate of the fifth transistor T5 is connected to the light-emitting control signal terminal EM, the source is connected to the first power supply voltage terminal VDD, and the drain is connected to the source of the driving transistor T3; the gate of the sixth transistor T6 is connected to the light-emitting control signal terminal EM, the source is connected to the drain of the driving transistor T3, and the drain is connected to the first electrode (anode) of the light-emitting device D1.

[0061] The voltage compensation sub-circuit 104 includes: a second storage capacitor C2 and an eighth transistor T8; one end of the second storage capacitor C2 is connected to the switch signal terminal SW, and the other end is connected to the gate of the eighth transistor T8; the gate of the eighth transistor T8 is connected to the other end of the second storage capacitor C2, the source is connected to the compensation voltage terminal Vrw, and the drain is connected to the first node N1; the gate and source of the eighth transistor T8 are electrically connected by a jumper wire.

[0062] Optionally, the voltage at the compensation voltage terminal Vrw is greater than the voltage at the first initialization signal terminal Vint1; for example, the voltage at the compensation voltage terminal Vrw is a positive voltage. The voltage value at the compensation voltage terminal Vrw can be a fixed voltage between VGMP (black state voltage, usually a high voltage) and the first power supply voltage terminal VDD to better compensate the first node. For example, the voltage at the compensation voltage terminal Vrw can be 6.8–7.3V. Of course, the voltage at the compensation voltage terminal Vrw can also be dynamically adjusted according to the Vth offset of T2 or T1.

[0063] One end of the first storage capacitor C1 is connected to the first node N1, and the other end is connected to the first power supply voltage terminal VDD. The first electrode (anode) of the light-emitting device D1 is connected to the drain of the sixth transistor T6 and the drain of the seventh transistor T7, and the second electrode (cathode) is connected to the second power supply voltage terminal VSS.

[0064] Optionally, one end of the first storage capacitor C1 is connected to the first node N1, and the other end is connected to a reference voltage Vref.

[0065] Figure 4 for Figure 3 The timing diagram of the pixel driving circuit shown below will be combined with... Figure 4 The timing diagram shown is for Figure 3 The operation of the pixel driving circuit shown will be described in further detail.

[0066] In the first stage, a low-level signal is input to the Reset signal terminal, and the first transistor T1 and the seventh transistor T7 are turned on. The first initialization signal is input to the first node N1 through the first transistor T1, and the second initialization signal is input to the anode of the light-emitting device D1 through the seventh transistor T7, so as to initialize the voltage of the first node N1 and the voltage of the anode of the light-emitting device D1, and prevent the voltage input of the previous frame of display from affecting the current display.

[0067] In the second stage, a low-level signal is input to the scan signal terminal (Gate), turning on the second transistor T2 and the fourth transistor T4. The gate and drain of the driving transistor T3 are shorted by the second transistor T2, allowing the threshold voltage of the driving transistor T3 to be read and input to the first node N1 along with the data signal, thus realizing the input of the data signal and threshold voltage compensation. The first storage capacitor C1 can store the voltage of the first node N1.

[0068] In the third stage, a low-level signal is input to the light-emitting control signal terminal EM, and the fifth transistor T5 and the sixth transistor T6 are turned on. The first power supply voltage terminal VDD and the second power supply voltage terminal VSS form a current loop through the light-emitting device D1, which can provide driving current for the light-emitting device D1, so that the light-emitting device D1 emits light. The brightness of the light-emitting device D1 can be adjusted by controlling the gray level voltage of the data signal to adjust the turn-on degree of the driving transistor T3.

[0069] In the third stage, when the display is functioning normally, the gate and source of the eighth transistor T8 are shorted, the switching signal and compensation voltage are both high, and the eighth transistor T8 is in the off state. The other transistors and capacitors operate normally to achieve normal display functionality. When a bright spot appears on the display, the shorting connection between the gate and source of the eighth transistor T8 can be broken, and the switching signal can be switched on to turn on the eighth transistor T8, for example, by changing the switching signal from high to low. At this time, under the bootstrap effect of the second storage capacitor C2, the gate voltage of the eighth transistor T8 can be pulled low, causing the eighth transistor T8 to conduct. The compensation voltage can be input to the first node N1 through the eighth transistor T8 to compensate for the voltage of the first node N1, ensuring that the voltage of the first node N1 reaches the preset voltage, preventing voltage leakage at the first node N1, and thus repairing the bright spot problem in the display.

[0070] Secondly, embodiments of this disclosure provide a display device, which includes a pixel driving circuit as provided in any of the above embodiments, and further includes: a plurality of first shift registers, a plurality of second shift registers, and a plurality of third shift registers; the output terminal of each first shift register is connected to the scan signal terminal of the pixel driving circuit of the corresponding row; the output terminal of each second shift register is connected to the light emission control signal terminal of the pixel driving circuit of the corresponding row; and the output terminal of each third shift register is connected to the switch signal terminal of the pixel driving circuit of the corresponding row.

[0071] Optionally, embodiments of this disclosure provide a display device including a pixel driving circuit as provided in any of the above embodiments, and further including: a plurality of fourth shift registers, the output terminal of each fourth shift register being connected to a reset signal terminal in the pixel driving circuit of the corresponding row. The plurality of fourth shift registers can provide a reset signal to the reset signal terminal in the display device. A plurality of first shift registers can provide a scan signal to the scan line in the display device, a plurality of second shift registers can provide a light emission control signal to the light emission control signal terminal in the display device, and a plurality of third shift registers can provide a switching signal to the switching signal terminal in the display device.

[0072] Optionally, the operating time of the switch signal SW (i.e., the turn-on time of the eighth transistor T8) at least partially overlaps with the operating time of the light emission control signal EM. For example, in the third stage, both the switch signal SW and the light emission control signal EM are low-level signals. Thus, the operation of the switch signal SW can facilitate the repair of dead pixels during the display stage. Optionally, the timing of the second shift register is the same as that of the third shift register; or, the light emission control signal terminal is connected to the same shift register as the switch signal terminal in the pixel driving circuit. This simplifies or reduces the number of shift registers.

[0073] Optionally, the operating time of the switch signal SW (i.e., the turn-on time of the eighth transistor) at least partially overlaps with the data input time (i.e., the operating time of the scan signal Gate). For example, in the second stage, both the switch signal SW and the scan signal Gate are low-level signals. This facilitates the compensation voltage during the data writing stage, which can be input to the first node N1 through the eighth transistor T8 to compensate for the voltage of the first node N1, ensuring that the voltage of the first node N1 reaches the preset voltage, avoiding voltage leakage in the first node N1, and better achieving threshold compensation of the driving transistor.

[0074] Optionally, the compensation voltage Vrw can be a variable voltage. For example, it can be 0 when the voltage compensation sub-circuit 104 is not working (e.g., when the eighth transistor T8 is off); and it can be Vrw when the voltage compensation sub-circuit 104 is working (e.g., when the eighth transistor T8 is on), which helps to save power consumption.

[0075] In the display device provided in this embodiment, when the display screen is displayed normally, the voltage compensation sub-circuit 104 is in a non-operating state, while the initialization sub-circuit 101, driving transistor T3, first storage capacitor C1, data writing sub-circuit 102, and light emission control sub-circuit 103 operate normally to achieve normal display function. When a bright spot appears in the display screen, under the control of the switch signal, the voltage compensation sub-circuit 104 is in an operating state, and can input the compensation voltage to the first node N1 to compensate the voltage of the first node N1, so that the voltage of the first node N1 reaches the preset voltage, avoiding voltage leakage of the first node N1, thereby repairing the bright spot in the display screen. At the same time, the display brightness at this point is the same as the surrounding display brightness, and no dark spot defects are generated, thereby improving the display effect and meeting the user's needs.

[0076] Thirdly, embodiments of this disclosure provide a method for repairing bright spots in a display screen, which can employ the pixel driving circuit provided in any of the above embodiments. Figure 5 This is a flowchart illustrating a method for repairing bright spots in a display screen according to an embodiment of the present disclosure. Figure 5 As shown, the bright spot repair method for the display screen includes the following steps S501 to S502.

[0077] S501 scans the pixel driving circuit of each row according to the preset timing sequence to display the preset display screen.

[0078] S502 If a bright spot appears in the preset display screen, in response to the switch signal, the voltage of the first node in the pixel driving circuit at the bright spot is compensated using a compensation voltage.

[0079] When the display screen is functioning normally, the voltage compensation sub-circuit 104 in the pixel driving circuit is in a non-operating state. The initialization sub-circuit 101, driving transistor T3, first storage capacitor C1, data writing sub-circuit 102, and light emission control sub-circuit 103 operate normally to achieve normal display functionality. When a bright spot appears on the display screen, the voltage compensation sub-circuit 104 activates under the control of a switching signal. It inputs a compensation voltage to the first node N1 to compensate for the voltage of the first node N1, ensuring that the voltage of the first node N1 reaches a preset voltage. This prevents voltage leakage at the first node N1 and thus repairs the bright spot problem.

[0080] Specifically, S502, in response to the switching signal, compensates the voltage of the first node in the pixel driving circuit at the bright spot using a compensation voltage, including:

[0081] The shorting wire between the gate and source of the eighth transistor T8 in the pixel driving circuit at the bright spot is cut off; the switching signal of the corresponding row's switching signal terminal SW is changed from the non-working level to the working level, so that the eighth transistor T8 is turned on to input the compensation voltage to the first node.

[0082] When the display is functioning normally, the gate and source of the eighth transistor T8 are shorted, the switching signal and compensation voltage are both high, and the eighth transistor T8 is in the off state. The other transistors and capacitors operate normally to achieve normal display functionality. When a bright spot appears on the display, the shorting wire between the gate and source of the eighth transistor T8 can be broken using a laser. Simultaneously, the switching signal changes from high to low. At this time, under the bootstrap effect of the second storage capacitor C2, the gate voltage of the eighth transistor T8 can be pulled low, causing the eighth transistor T8 to conduct. The compensation voltage can be input to the first node N1 through the eighth transistor T8 to compensate for the voltage of the first node N1, ensuring that the voltage of the first node N1 reaches the preset voltage, preventing voltage leakage at the first node N1, and thus repairing the bright spot problem.

[0083] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A pixel driving circuit, characterized by comprising: The pixel driving circuit comprises an initialization sub-circuit, a driving transistor, a first storage capacitor, a data writing sub-circuit, a light-emitting control sub-circuit and a voltage compensation sub-circuit. The initialization sub-circuit is configured to initialize the voltage of a first node by using a first initialization signal in response to a reset signal, and is also configured to initialize the voltage of a first electrode of a light-emitting device by using a second initialization signal in response to the reset signal; the first node is a connection point among the initialization sub-circuit, the control electrode of the driving transistor and the first storage capacitor. The first storage capacitor is configured to store the voltage of the first node. The data writing sub-circuit is configured to write a data signal into the first node in response to a scanning signal, and is also configured to write the threshold voltage of the driving transistor into the first node. The light-emitting control sub-circuit is configured to provide a driving voltage to the first electrode of the light-emitting device in response to a light-emitting control signal. The voltage compensation sub-circuit is configured to compensate the voltage of the first node by using a compensation voltage in response to a switching signal. The voltage compensation sub-circuit comprises a second storage capacitor and an eighth transistor. One end of the second storage capacitor is connected to a switching signal end, and the other end is connected to the control electrode of the eighth transistor. The control electrode of the eighth transistor is connected to the other end of the second storage capacitor, the first electrode is connected to a compensation voltage end, and the second electrode is connected to the first node. The control electrode and the first electrode of the eighth transistor are electrically connected through a shorting wire.

2. The pixel driving circuit according to claim 1, characterized in that, The initialization sub-circuit comprises a first transistor; the control electrode of the first transistor is connected to a reset signal end, the first electrode is connected to a first initialization signal end, and the second electrode is connected to the first node. The initialization sub-circuit further comprises a seventh transistor; the control electrode of the seventh transistor is connected to the reset signal end, the first electrode is connected to a second initialization signal end, and the second electrode is connected to the first electrode of the light-emitting device.

3. The pixel driving circuit of claim 1, wherein, The data writing sub-circuit comprises a fourth transistor. The control electrode of the fourth transistor is connected to a scanning signal end, the first electrode is connected to a data signal end, and the second electrode is connected to the first electrode of the driving transistor. The data writing sub-circuit further comprises a second transistor; the control electrode of the second transistor is connected to the scanning signal end, the first electrode is connected to the second electrode of the driving transistor, and the second electrode is connected to the first node.

4. The pixel driving circuit of claim 1, wherein, The light-emitting control sub-circuit comprises a fifth transistor and / or a sixth transistor. The control electrode of the fifth transistor is connected to a light-emitting control signal end, the first electrode is connected to a first power voltage end, and the second electrode is connected to the first electrode of the driving transistor. The control electrode of the sixth transistor is connected to the light-emitting control signal end, the first electrode is connected to the second electrode of the driving transistor, and the second electrode is connected to the first electrode of the light-emitting device.

5. A display device, characterized by comprising: The display device comprises the pixel driving circuit according to any one of claims 1 to 4.

6. The display device according to claim 5, wherein The display device further comprises a plurality of first shift registers, a plurality of second shift registers and a plurality of third shift registers. The output end of each first shift register is connected to the scanning signal end of the pixel driving circuit of a corresponding row. An output terminal of each of the second shift registers is connected to a light-emitting control signal terminal of the pixel driving circuit of the corresponding row; An output terminal of each of the third shift registers is connected to a switch signal terminal in the pixel driving circuit of the corresponding row.

7. A method for repairing a bright spot of a display picture, using the pixel driving circuit according to any one of claims 1 to 4, characterized in that, The bright spot repairing method of the display picture comprises: According to a preset timing, scanning each row of pixel driving circuit to display a preset display picture; If a bright spot appears in the preset display picture, then in response to a switch signal, compensating the voltage of a first node in the pixel driving circuit at the bright spot with a compensation voltage.

8. The method of repairing bright spots in a display picture according to claim 7, wherein, The response to the switch signal and the compensation of the voltage of the first node in the pixel driving circuit at the bright spot with the compensation voltage comprises: Cutting off a short-circuit wire between the control electrode and the first electrode of the eighth transistor in the pixel driving circuit at the bright spot; Converting the switch signal of the switch signal terminal of the corresponding row from a non-working level to a working level, so that the eighth transistor is turned on to input the compensation voltage to the first node.

9. The method of repairing bright spots in a display picture according to claim 8, wherein, Cutting off the short-circuit wire between the control electrode and the first electrode of the eighth transistor in the pixel driving circuit at the bright spot with a laser.

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