Short-circuit protection circuit of light-emitting device, pixel circuit and display substrate

Abstract

The embodiment of the invention provides a light-emitting device short-circuit protection circuit, a pixel circuit and a display substrate, a first short-circuit protection module is used for controlling disconnection between a cathode of a first light-emitting device and an anode of a second light-emitting device when the first light-emitting device is in a short-circuit state; the first voltage control module is used for controlling the potential of the anode of the second light-emitting device at a preset voltage value when the first light-emitting device is in a short-circuit state and a first switch sub-module of the first voltage control module is in a conducting state; the second short-circuit protection module is used for controlling the disconnection between the cathode of the second light-emitting device and the cathode of the power supply when the second light-emitting device is in the short-circuit state; and the second voltage control module is used for controlling the potential of the anode of the second light-emitting device at a preset voltage value when the second light-emitting device is in a short-circuit state and a second switch sub-module of the second voltage control module is in a conducting state.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a light-emitting device short-circuit protection circuit, a pixel circuit, and a display substrate. Background Art

[0002] Amidst the ongoing innovation in display technology, Mini LED displays (Mini Light Emitting Diodes, which use light-emitting diodes (LEDs) with a die size of approximately 100 microns as a backlight) have emerged as a hot development in the display industry due to their superior performance. Mini LED displays utilize smaller LEDs to achieve higher brightness, contrast, and a wider color gamut, providing users with a stunning visual experience. Demand is growing in high-end esports, film and television production, professional design, and other fields.

[0003] However, like many emerging technologies, MiniLED displays still face numerous challenges in their development. For example, current MiniLED displays on the market generally lack a comprehensive protection circuit design, resulting in low reliability. Specifically, in daily use, ESD (electrostatic discharge) or LED defects can cause the LED to short-circuit. At this time, due to the impact of overvoltage and overcurrent, the light path may be completely damaged, or the entire display screen may not work properly, thereby affecting the reliability of the MiniLED display. Therefore, how to implement short-circuit protection for MiniLED displays has become an urgent problem to be solved. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a light emitting device short circuit protection circuit, a pixel circuit, and a display substrate to improve the reliability of the display. The specific technical solutions are as follows:

[0005] In a first aspect, an embodiment of the present application provides a short-circuit protection circuit for a light-emitting device, the circuit comprising:

[0006] A first light-emitting device, a second light-emitting device, a first short-circuit protection module, a second short-circuit protection module, a first voltage control module, and a second voltage control module; the first light-emitting device and the second light-emitting device are connected in series between the positive electrode and the negative electrode of the power supply;

[0007] The first short-circuit protection module is configured to control the disconnection between the cathode of the first light-emitting device and the anode of the second light-emitting device when the first light-emitting device is in a short-circuit state;

[0008] The first voltage control module is configured to, when the first light-emitting device is not in a short-circuited state, have its own first switch submodule in an off state, and to work together with the first light-emitting device to control the potential of the anode of the second light-emitting device to a preset voltage value; and, when the first light-emitting device is in a short-circuited state, have its own first switch submodule in an on state, and to control the potential of the anode of the second light-emitting device to a preset voltage value; wherein the preset voltage value is the supply voltage required for the second light-emitting device to operate normally;

[0009] The second short-circuit protection module is configured to control the disconnection between the cathode of the second light-emitting device and the negative electrode of the power supply when the second light-emitting device is in a short-circuit state;

[0010] The second voltage control module is used to control the potential of the anode of the second light emitting device to a preset voltage value by turning on the second switch submodule thereof when the second light emitting device is in a short-circuit state.

[0011] In a possible implementation, the first voltage control module includes a first switch submodule and a voltage divider submodule;

[0012] The input end of the voltage divider module is connected to the anode of the first light-emitting device, the first output end of the voltage divider module is connected to the anode of the second light-emitting device, and the second output end of the voltage divider module is connected to the input end of the first switch submodule; the control end of the first switch submodule is connected to the cathode of the first light-emitting device, and the output end of the first switch submodule is connected to the negative electrode of the power supply;

[0013] The first switch submodule is configured to be in an off state when the first light emitting device is not in a short-circuit state, and to be in an on state when the first light emitting device is in a short-circuit state;

[0014] The voltage divider submodule is used to control the potential of the anode of the second light-emitting device at a preset voltage value by working together with the first light-emitting device when the first switch submodule is in the off state; and to control the potential of the anode of the second light-emitting device at a preset voltage value by working together with the first light-emitting device when the first switch submodule is in the on state.

[0015] In a possible implementation, the second voltage control module includes a voltage stabilizing submodule and a second switch submodule;

[0016] The control end of the second switch submodule is connected to the cathode of the second light-emitting device, the input end of the second switch submodule is connected to the anode of the second light-emitting device, the output end of the second switch submodule is connected to the first end of the voltage stabilizing submodule; and the second end of the voltage stabilizing submodule is connected to the negative electrode of the power supply;

[0017] The second switch submodule is configured to be in a conducting state when the second light emitting device is in a short-circuit state, and to be in a shut-off state when the second light emitting device is in a non-short-circuit state;

[0018] The voltage stabilizing submodule is configured to clamp the potential of the anode of the second light emitting device to a preset voltage value when the second switch submodule is in the on state.

[0019] In a possible implementation, the first short-circuit protection module includes a first switching tube;

[0020] The control electrode of the first switching tube is connected to the anode of the first light-emitting device, the first electrode of the first switching tube is connected to the cathode of the first light-emitting device, and the second electrode of the first switching tube is connected to the anode of the second light-emitting device;

[0021] The first switch tube is configured to be in a turned-off state when the first light-emitting device is in a short-circuit state, and to be in a turned-on state when the first light-emitting device is in a non-short-circuit state.

[0022] In a possible implementation manner, the second short-circuit protection module includes a second switching tube;

[0023] The control electrode of the second switch tube is connected to the anode of the second light emitting device, the first electrode of the second switch tube is connected to the cathode of the second light emitting device, and the second electrode of the second switch tube is connected to the negative electrode of the power supply;

[0024] The second switch tube is configured to be in a turned-off state when the second light emitting device is in a short-circuit state, and to be in a turned-on state when the second light emitting device is in a non-short-circuit state.

[0025] In a possible implementation, the voltage divider submodule includes a first resistor, a second resistor, and a third resistor; the first switch submodule includes a third switch tube;

[0026] The first electrode of the first resistor is connected to the anode of the first light-emitting device, and the second electrode of the first resistor is connected to the first electrode of the second resistor and the first electrode of the third resistor respectively; the second electrode of the second resistor is connected to the anode of the second light-emitting device; the second electrode of the third resistor is connected to the first electrode of the third switching tube; the control electrode of the third switching tube is connected to the cathode of the first light-emitting device, and the second electrode of the third switching tube is connected to the negative electrode of the power supply.

[0027] In a possible implementation, the second switch submodule includes a fourth switch tube, and the voltage stabilizing submodule includes a voltage stabilizing diode;

[0028] The control electrode of the fourth switching tube is connected to the cathode of the second light-emitting device, the first electrode of the fourth switching tube is connected to the anode of the second light-emitting device, the second electrode of the fourth switching tube is connected to the cathode of the voltage-stabilizing diode; and the anode of the voltage-stabilizing diode is connected to the negative electrode of the power supply.

[0029] In a second aspect, an embodiment of the present application provides a pixel circuit, which includes the light-emitting device short-circuit protection circuit described in any one of the first aspects above.

[0030] In a third aspect, an embodiment of the present application provides a display substrate, which includes a plurality of pixel circuits described in the second aspect.

[0031] In a fourth aspect, an embodiment of the present application provides a display device, comprising the display substrate described in the third aspect.

[0032] Beneficial effects of the embodiments of the present application:

[0033] The embodiment of the present application provides a light-emitting device short-circuit protection circuit, a pixel circuit, and a display substrate. The light-emitting device short-circuit protection circuit includes: a first light-emitting device, a second light-emitting device, a first short-circuit protection module, a second short-circuit protection module, a first voltage control module, and a second voltage control module; the first light-emitting device and the second light-emitting device are connected in series between the positive electrode and the negative electrode of the power supply; the first short-circuit protection module is used to control the disconnection between the cathode of the first light-emitting device and the anode of the second light-emitting device when the first light-emitting device is in a short-circuit state; the first voltage control module is used to control the first switch submodule of the first light-emitting device to be in a turned-off state when the first light-emitting device is in a non-short-circuit state, and the first switch submodule of the first light-emitting device is in a turned-off state, and the first switch submodule of the first light-emitting device is in a turned-off state. They work together to control the potential of the anode of the second light-emitting device to a preset voltage value; when the first light-emitting device is in a short-circuit state, its own first switch sub-module is in a conducting state, and its own function is to control the potential of the anode of the second light-emitting device to a preset voltage value; wherein the preset voltage value is the power supply voltage required for the second light-emitting device to work normally; the second short-circuit protection module is used to control the connection between the cathode of the second light-emitting device and the negative pole of the power supply to be disconnected when the second light-emitting device is in a short-circuit state; the second voltage control module is used to control the potential of the anode of the second light-emitting device to be in a preset voltage value when the second light-emitting device is in a short-circuit state. By setting a first short-circuit protection module and a first voltage control module, when the first light-emitting device is short-circuited, the first short-circuit protection module controls the disconnection between the cathode of the first light-emitting device and the anode of the second light-emitting device, and the first voltage control module supplies power to the second light-emitting device so that the second light-emitting device can operate normally. By setting a second short-circuit protection module and a second voltage control module, when the second light-emitting device is short-circuited, the second short-circuit protection module controls the disconnection between the cathode of the second light-emitting device and the negative pole of the power supply, and the second voltage control module controls the potential of the anode of the second light-emitting device to a preset voltage value so that the voltage drop of the first light-emitting device is the voltage drop required for its normal operation. In the event of a short circuit in the light-emitting device, the risks of overcurrent and overvoltage in the circuit are reduced, thereby improving the reliability of the display.

[0034] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0036] Figure 1A schematic diagram of a first structural example of a short-circuit protection circuit for a light-emitting device provided in an embodiment of the present application;

[0037] Figure 2 A second structural diagram of a short-circuit protection circuit for a light-emitting device provided in an embodiment of the present application;

[0038] Figure 3 A third structural diagram of the short-circuit protection circuit for a light-emitting device provided in an embodiment of the present application;

[0039] Figure 4 A fourth structural diagram of the short-circuit protection circuit for a light-emitting device provided in an embodiment of the present application;

[0040] Figure 5a A schematic diagram of a first structure of a pixel circuit provided in an embodiment of the present application;

[0041] Figure 5b A second structural diagram of a pixel circuit provided in an embodiment of the present application;

[0042] Figure 6 A schematic structural diagram of a display substrate provided in an embodiment of the present application;

[0043] Figure 7 A schematic structural diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field based on this application are within the scope of protection of this application.

[0045] Amidst the ongoing innovation in display technology, Mini LED displays (Mini Light Emitting Diodes, which use light-emitting diodes (LEDs) with a die size of approximately 100 microns as a backlight) have emerged as a hot development in the display industry due to their superior performance. Mini LED displays utilize smaller LEDs to achieve higher brightness, contrast, and a wider color gamut, providing users with a stunning visual experience. Demand is growing in high-end esports, film and television production, professional design, and other fields.

[0046] However, like many emerging technologies, MiniLED displays still face numerous challenges in their development. For example, current MiniLED displays on the market generally lack a comprehensive protection circuit design, resulting in low reliability. Specifically, in daily use, ESD (electrostatic discharge) or LED defects can cause the LED to short-circuit. At this time, due to the impact of overvoltage and overcurrent, the light path may be completely damaged, or the entire display screen may not work properly, thereby affecting the reliability of the MiniLED display. Therefore, how to implement short-circuit protection for MiniLED displays has become an urgent problem to be solved.

[0047] In order to improve at least one of the above problems, embodiments of the present application provide a light-emitting device short-circuit protection circuit, a pixel circuit, and a display substrate.

[0048] First, the professional terms that may be used in the embodiments of this application are explained:

[0049] A short circuit occurs when current flows through a circuit without passing through a normal load. For example, if the live and neutral wires of an electrical wire come into direct contact, or if a component in the circuit is damaged, the current has a path with minimal resistance.

[0050] Short-circuit protection: At the moment a short circuit occurs or in a very short time, it detects the abnormal current increase and takes measures to cut off the circuit to prevent excessive current from damaging circuit equipment (such as power supplies, wires, electronic components, etc.).

[0051] Overcurrent: The current in the circuit is determined by factors such as the load and power supply. When the current exceeds the maximum value allowed for normal operation of the equipment, it is overcurrent. It may be due to a short circuit or a sudden increase in load.

[0052] Overcurrent protection: When the current exceeds the set value, the abnormal current increase is detected and the circuit will be cut off or the current will be adjusted in time to prevent electrical equipment from heating and being damaged due to excessive current passing through for a long time, thereby ensuring the normal operation of the circuit.

[0053] Overvoltage: This refers to the voltage in a circuit exceeding the upper limit of the voltage that the device can withstand for normal operation. Excessive voltage can cause damage to electronic equipment, such as capacitor breakdown and damage to semiconductor devices.

[0054] Overvoltage protection: It monitors the voltage in the circuit. When the voltage exceeds the set safety threshold, it reduces the voltage or cuts off the circuit in various ways to protect the equipment from the harm of overvoltage.

[0055] Overheating and overheating protection: Overheating refers to the temperature of components or equipment in the circuit rising beyond the normal operating range due to long-term operation, overload, poor heat dissipation, etc. Excessive temperature will affect the performance and life of electronic components, and may even cause safety accidents such as fire. Overheating protection is to prevent this from happening.

[0056] Next, the light emitting device short circuit protection circuit 1 provided in the embodiment of the present application is described in detail. Figure 1 , is a schematic diagram of a first structure of a light emitting device short-circuit protection circuit 1 provided in an embodiment of the present application, wherein the circuit 1 comprises:

[0057] A first light-emitting device D1, a second light-emitting device D2, a first short-circuit protection module 13, a second short-circuit protection module 14, a first voltage control module 15, and a second voltage control module 16; the first light-emitting device D1 and the second light-emitting device D2 are connected in series between the positive power supply VLED_INPUT and the negative power supply VLED_OUTPUT; the anode of the first light-emitting device D1 is connected to the positive power supply VLED_INPUT;

[0058] The control end of the first short-circuit protection module 13 is connected to the anode of the first light-emitting device D1, the input end of the first short-circuit protection module 13 is connected to the cathode of the first light-emitting device D1, and the output end of the first short-circuit protection module 13 is connected to the anode of the second light-emitting device D2; the control end of the second short-circuit protection module 14 is connected to the anode of the second light-emitting device D2, the input end of the second short-circuit protection module 14 is connected to the cathode of the second light-emitting device D2, and the output end of the second short-circuit protection module 14 is connected to the negative electrode of the power supply VLED_OUTPUT; the control end of the first voltage control module 15 is connected to the first light-emitting device D1. The cathode of the optical device D1 is connected, the input end of the first voltage control module 15 is connected to the anode of the first light-emitting device D1, the first output end of the first voltage control module 15 is connected to the anode of the second light-emitting device D2, and the second output end of the first voltage control module 15 is connected to the negative pole of the power supply VLED_OUTPUT; the control end of the second voltage control module 16 is connected to the cathode of the second light-emitting device D2, the input end of the second voltage control module 16 is connected to the anode of the second light-emitting device D2, and the output end of the second voltage control module 16 is connected to the negative pole of the power supply VLED_OUTPUT.

[0059] The first short-circuit protection module 13 is configured to control the disconnection between the cathode of the first light-emitting device D1 and the anode of the second light-emitting device D2 when the first light-emitting device D1 is in a short-circuit state;

[0060] The first voltage control module 15 is configured to, when the first light-emitting device D1 is in a non-short-circuited state (normal working state), have its first switch submodule 151 in an off state, and to work together with the first light-emitting device D1 to control the potential of the anode of the second light-emitting device D2 to a preset voltage value; and when the first light-emitting device D1 is in a short-circuited state, have its first switch submodule 151 in an on state, and to control the potential of the anode of the second light-emitting device D2 to a preset voltage value; wherein the preset voltage value is the supply voltage required for the normal working of the second light-emitting device D2;

[0061] The second short-circuit protection module 14 is configured to control the disconnection between the cathode of the second light-emitting device D2 and the negative electrode of the power supply VLED_OUTPUT when the second light-emitting device D2 is in a short-circuit state;

[0062] The second voltage control module 16 is used to control the potential of the anode of the second light emitting device D2 to a preset voltage value by turning on the second switch submodule 161 when the second light emitting device D2 is in a short-circuit state.

[0063] The first light emitting device D1 and the second light emitting device D2 may be light emitting diodes (LEDs), or other types of light emitting devices.

[0064] When the first light emitting device D1 is in normal working state, the first short circuit protection module 13 controls the conduction between the cathode of the first light emitting device D1 and the anode of the second light emitting device D2. At this time, the first switch submodule 151 of the first voltage control module 15 is in the off state.

[0065] When the first light-emitting device D1 is in a short-circuit state, the first short-circuit protection module 13 controls the disconnection between the cathode of the first light-emitting device D1 and the anode of the second light-emitting device D2 to prevent the first light-emitting device D1 from continuing to overcurrent and overheat, causing damage to the second light-emitting device D2 and other devices in the circuit, or even causing a fire, resulting in greater losses. At this time, the first switch submodule 151 of the first voltage control module 15 is in an on state, and the first voltage control module 15 controls the potential of the anode of the second light-emitting device D2 to a preset voltage value, and supplies power to the second light-emitting device D2, so that the second light-emitting device D2 can work normally and prevent the second light-emitting device D2 from burning due to overvoltage.

[0066] When the second light-emitting device D2 is in normal working state, the second short-circuit protection module 14 controls the conduction between the cathode of the second light-emitting device D2 and the negative electrode of the power supply VLED_OUTPUT. At this time, the second switch submodule 161 of the second voltage control module 16 is in the off state, and the second voltage control module 16 does not work.

[0067] When the second light-emitting device D2 is in a short-circuit state, the second short-circuit protection module 14 controls the disconnection between the cathode of the second light-emitting device D2 and the negative electrode of the power supply VLED_OUTPUT to prevent the second light-emitting device D2 from continuing to overcurrent and overheat, causing damage to the first light-emitting device D1 and other devices in the circuit, or even causing fire, resulting in greater losses. At this time, the second switch submodule 161 of the second voltage control module 16 is in a conducting state, and the second voltage control module 16 is in a working state, controlling the potential of the anode of the second light-emitting device D2 to a preset voltage value, so that the voltage drop of the first light-emitting device D1 is the voltage drop required for its normal operation, thereby preventing the first light-emitting device D1 from burning due to overvoltage.

[0068] When both the first light-emitting device D1 and the second light-emitting device D2 are in a short-circuit state, the first short-circuit protection module 13 controls the cathode of the first light-emitting device D1 and the anode of the second light-emitting device D2 to be disconnected, and the second short-circuit protection module 14 controls the cathode of the second light-emitting device D2 and the negative electrode of the power supply VLED_OUTPUT to be disconnected.

[0069] In the embodiment of the present application, by providing a first short-circuit protection module 13 and a first voltage control module 15, when the first light-emitting device D1 is short-circuited, the first short-circuit protection module 13 controls the disconnection between the cathode of the first light-emitting device D1 and the anode of the second light-emitting device D2 to prevent the first light-emitting device D1 from continuously overcurrent and overheating, causing damage to the second light-emitting device D2 and other devices in the circuit, and even causing fire, resulting in greater losses. At this time, the first voltage control module 15 supplies power to the second light-emitting device D2 to enable the second light-emitting device D2 to operate normally, preventing the second light-emitting device D2 from burning due to overvoltage; by providing a second short-circuit protection module 14 and a second voltage control module 16, in the second light-emitting device D1 When the optical device D2 is short-circuited, the second short-circuit protection module 14 controls the disconnection between the cathode of the second light-emitting device D2 and the negative electrode of the power supply VLED_OUTPUT to prevent the second light-emitting device D2 from continuing to overcurrent and overheat, causing damage to the first light-emitting device D1 and other devices in the circuit, or even causing a fire, resulting in greater losses. At this time, the second voltage control module 16 controls the potential of the anode of the second light-emitting device D2 to a preset voltage value, so that the voltage drop of the first light-emitting device D1 is the voltage drop required for its normal operation, preventing the first light-emitting device D1 from burning due to overvoltage. In the event of a short circuit in the light-emitting device, the risks of overcurrent, overheating, and overvoltage in the circuit are reduced, thereby improving the stability and reliability of the display.

[0070] In one possible implementation, see Figure 2 , the first voltage control module 15 includes a first switch submodule 151 and a voltage dividing submodule 152;

[0071] The input end of the voltage divider module 152 is connected to the anode of the first light-emitting device D1, the first output end of the voltage divider module 152 is connected to the anode of the second light-emitting device D2, and the second output end of the voltage divider module 152 is connected to the input end of the first switch submodule 151; the control end of the first switch submodule 151 is connected to the cathode of the first light-emitting device D1, and the output end of the first switch submodule 151 is connected to the negative electrode of the power supply VLED_OUTPUT;

[0072] The first switch submodule 151 is configured to be in an off state when the first light emitting device D1 is not in a short-circuit state, and to be in an on state when the first light emitting device D1 is in a short-circuit state;

[0073] The voltage divider submodule 152 is used to control the potential of the anode of the second light-emitting device D2 at a preset voltage value by working together with the first light-emitting device D1 when the first switch submodule 151 is in the off state; and to control the potential of the anode of the second light-emitting device D2 at a preset voltage value when the first switch submodule 151 is in the on state.

[0074] The voltage dividing submodule 152 may include only a voltage dividing resistor for voltage dividing, or may include a voltage dividing resistor for voltage dividing and a current limiting resistor for current limiting, and the specific selection may be made according to the actual situation of the circuit.

[0075] In the embodiment of the present application, when the first light-emitting device D1 is in a normal working state, the first switch submodule 151 is in an off state, and the voltage divider submodule 152 works together with the first light-emitting device D1 to control the potential of the anode of the second light-emitting device D2 to a preset voltage value; when the first light-emitting device D1 is in a short-circuit state, the first switch submodule 151 is in an on state, and the voltage divider submodule 152 controls the potential of the anode of the second light-emitting device D2 to a preset voltage value, and supplies power to the second light-emitting device D2, so that the second light-emitting device D2 can work normally, prevent the second light-emitting device D2 from burning due to overvoltage, and improve the stability and reliability of the display.

[0076] In one possible implementation, see Figure 3 , the second voltage control module 16 includes a voltage stabilizing submodule 162 and a second switch submodule 161;

[0077] The control end of the second switch submodule 161 is connected to the cathode of the second light-emitting device D2, the input end of the second switch submodule 161 is connected to the anode of the second light-emitting device D2, the output end of the second switch submodule 161 is connected to the first end of the voltage stabilizing submodule 162; and the second end of the voltage stabilizing submodule 162 is connected to the negative electrode of the power supply VLED_OUTPUT;

[0078] The second switch submodule 161 is configured to be turned on when the second light emitting device D2 is in a short-circuit state, and turned off when the second light emitting device D2 is not in a short-circuit state;

[0079] The voltage stabilizing submodule 162 is configured to clamp the potential of the anode of the second light emitting device D2 to a preset voltage value when the second switch submodule 161 is in the on state.

[0080] The voltage stabilizing submodule 162 may include a voltage stabilizing diode. When the reverse voltage of the voltage stabilizing diode reaches a critical breakdown voltage, the voltage stabilizing diode enters a reverse breakdown state. At this time, the voltage across the voltage stabilizing diode remains substantially constant, thereby achieving a voltage stabilizing function.

[0081] In the embodiment of the present application, when the second light-emitting device D2 is in a short-circuit state, the second switch submodule 161 is in an on state, and the voltage stabilizing submodule 162 clamps the potential of the anode of the second light-emitting device D2 to a preset voltage value, so that the voltage drop of the first light-emitting device D1 is the voltage drop required for its normal operation, thereby preventing the first light-emitting device D1 from burning due to overvoltage, thereby improving the stability and reliability of the display.

[0082] In one possible implementation, see Figure 4 , the first short-circuit protection module 13 includes a first switch tube Q1;

[0083] The control electrode of the first switch tube Q1 is connected to the anode of the first light emitting device D1, the first electrode of the first switch tube Q1 is connected to the cathode of the first light emitting device D1, and the second electrode of the first switch tube Q1 is connected to the anode of the second light emitting device D2;

[0084] The first switch tube Q1 is configured to be in a turned-off state when the first light emitting device D1 is in a short-circuit state, and to be in a turned-on state when the first light emitting device D1 is in a non-short-circuit state.

[0085] When the first light-emitting device D1 is in a short-circuit state, the first switch tube Q1 is in a turned-off state, so that the cathode of the first light-emitting device D1 is disconnected from the anode of the second light-emitting device D2, thereby preventing the first light-emitting device D1 from continuously overcurrent and overheating, causing damage to the second light-emitting device D2 and other devices in the circuit, and even causing fire, resulting in greater losses.

[0086] The first switch tube Q1 can be an N-type MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor), an NPN transistor, or an N-type TFT (Thin Film Transistor), which is not specifically limited in this application.

[0087] In one possible implementation, see Figure 4 , the second short-circuit protection module 14 includes a second switch tube Q2;

[0088] The control electrode of the second switch tube Q2 is connected to the anode of the second light emitting device D2, the first electrode of the second switch tube Q2 is connected to the cathode of the second light emitting device D2, and the second electrode of the second switch tube Q2 is connected to the negative electrode of the power supply VLED_OUTPUT;

[0089] The second switch tube Q2 is configured to be in a turned-off state when the second light emitting device D2 is in a short-circuit state, and to be in a turned-on state when the second light emitting device D2 is in a non-short-circuit state.

[0090] When the second light-emitting device D2 is in a short-circuit state, the second switch tube Q2 is in a turned-off state, so that the cathode of the second light-emitting device D2 is disconnected from the negative electrode of the power supply VLED_OUTPUT, thereby preventing the second light-emitting device D2 from continuously overcurrent and overheating, causing damage to the first light-emitting device D1 and other devices in the circuit, and even causing fire, resulting in greater losses.

[0091] The second switch tube Q2 can be an N-type MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor), an NPN transistor, or an N-type TFT (Thin Film Transistor), which is not specifically limited in this application.

[0092] In one possible implementation, see Figure 4 The voltage divider module 152 includes a first resistor R1, a second resistor R2, and a third resistor R3; the first switch module 151 includes a third switch tube Q3;

[0093] A first electrode of the first resistor R1 is connected to the anode of the first light-emitting device D1, and a second electrode of the first resistor R1 is connected to the first electrode of the second resistor R2 and the first electrode of the third resistor R3 respectively; a second electrode of the second resistor R2 is connected to the anode of the second light-emitting device D2; a second electrode of the third resistor R3 is connected to the first electrode of the third switch tube Q3; a control electrode of the third switch tube Q3 is connected to the cathode of the first light-emitting device D1, and a second electrode of the third switch tube Q3 is connected to the negative electrode of the power supply VLED_OUTPUT.

[0094] When the first light emitting device D1 is in a short-circuit state, the third switch tube Q3 is in a turned-on state. When the first light emitting device D1 is in a normal working state, the third switch tube Q3 is in a turned-off state.

[0095] The first resistor R1 and the third resistor R3 are voltage-dividing resistors, which are used to divide the voltage of the positive electrode VLED_INPUT of the power supply when the first light-emitting device D1 is in a short-circuit state; the second resistor R2 is a current-limiting resistor, which is used to limit the current in the conduction path of the second light-emitting device D2 when the first light-emitting device D1 is in a short-circuit state.

[0096] It should be noted that the resistance of the first resistor R1 and the second resistor R2 is greater than the internal resistance of the first light emitting device D1.

[0097] In one possible implementation, see Figure 4 , the second switch submodule 161 includes a fourth switch tube Q4, and the voltage stabilizing submodule 162 includes a voltage stabilizing diode D3;

[0098] The control electrode of the fourth switch tube Q4 is connected to the cathode of the second light-emitting device D2, the first electrode of the fourth switch tube Q4 is connected to the anode of the second light-emitting device D2, the second electrode of the fourth switch tube Q4 is connected to the cathode of the Zener diode D3; the anode of the Zener diode D3 is connected to the negative electrode of the power supply VLED_OUTPUT.

[0099] When the second light emitting device D2 is in a short-circuit state, the fourth switch tube Q4 is in a turned-on state. When the second light emitting device D2 is in a normal working state, the fourth switch tube Q4 is in a turned-off state.

[0100] Zener diode D3 is used to clamp the potential of the anode of second light-emitting device D2 to a preset voltage value when fourth switch Q4 is in the on state. When the reverse voltage of Zener diode D3 reaches the critical breakdown voltage, Zener diode D3 enters a reverse breakdown state. At this time, the voltage across Zener diode D3 remains essentially constant, achieving voltage stabilization.

[0101] For any switching tube in the short-circuit protection circuit of the light-emitting device of the present application, when the switching tube is an N-type MOS tube / TFT tube, the control electrode of the switching tube is the gate, the first electrode of the switching tube is the source / drain, and the second electrode of the switching tube is the drain / source corresponding to the first electrode; when the switching tube is an NPN transistor, the control electrode of the switching tube is the base, the first electrode of the switching tube is the emitter / collector, and the second electrode of the switching tube is the collector / emitter corresponding to the first electrode.

[0102] It is understandable that Figure 4 In the figure, each switch tube is illustrated as an N-type MOS tube.

[0103] In order to understand the solution of this application more clearly, Figure 4The following explanation is based on the example that the supply voltage of the positive power supply VLED_INPUT is 12V and the voltage of the negative power supply VLED_OUTPUT is 0V:

[0104] When the first light-emitting device D1 is in a normal working state, the gate voltage of the first switch tube Q1 (connected to the anode of the first light-emitting device D1) is 12V, the source voltage of the first switch tube Q1 (connected to the cathode of the first light-emitting device D1) is 6V, the gate-source voltage VGS of the first switch tube Q1 is 6V, and the threshold voltage Vth of the first switch tube Q1 is 2V. At this time, the turn-on condition of the first switch tube Q1 is met, and the first switch tube Q1 is in the on state.

[0105] When the first light-emitting device D1 is in a short-circuit state, the gate voltage of the first switch tube Q1 is 12V, the source voltage of the first switch tube Q1 is 12V, the gate-source voltage VGS of the first switch tube Q1 is 0V, and the threshold voltage Vth of the MOS tube is 2V. At this time, the turn-on condition of the first switch tube Q1 is not met, the first switch tube Q1 is in a turn-off state, and the cathode of the first light-emitting device D1 is disconnected from the anode of the second light-emitting device D2, preventing the first light-emitting device D1 from continuously overcurrent and overheating, causing damage to the second light-emitting device D2 and other devices in the circuit, or even causing fire, resulting in significant losses.

[0106] When the second light-emitting device D2 is in normal working state, the gate voltage of the second switch tube Q2 (connected to the anode of the second light-emitting device D2) is 6V, the source voltage of the second switch tube Q2 (connected to the cathode of the second light-emitting device D2) is 0V, the gate-source voltage VGS of the second switch tube Q2 is 6V, and the threshold voltage Vth of the second switch tube Q2 is 2V. At this time, the turn-on condition of the second switch tube Q2 is met, and the second switch tube Q2 is in the on state.

[0107] When the second light-emitting device D2 is in a short-circuit state, the gate voltage of the second switch tube Q2 is 6V, the source voltage of the second switch tube Q2 is 6V, the gate-source voltage VGS of the second switch tube Q2 is 0V, and the threshold voltage Vth of the second switch tube Q2 is 2V. At this time, the turn-on condition of the second switch tube Q2 is not met, the second switch tube Q2 is in a turn-off state, and the cathode of the second light-emitting device D2 is disconnected from the negative electrode of the power supply VLED_OUTPUT, preventing the second light-emitting device D2 from continuously overcurrent and overheating, causing damage to the first light-emitting device D1 and other devices in the circuit, or even causing fire, resulting in significant losses.

[0108] When the first light-emitting device D1 is in a normal working state, the gate voltage of the third switch tube Q3 (connected to the cathode of the first light-emitting device D1) is 6V, the source voltage of the third switch tube Q3 (connected to the negative electrode of the power supply VLED_OUTPUT) is 0V, the gate-source voltage VGS of the third switch tube Q3 is 6V, and the threshold voltage Vth of the third switch tube Q3 is 7V. At this time, the turn-on condition of the third switch tube Q3 is not met, and the third switch tube Q3 is in the off state.

[0109] When the first light-emitting device D1 is in a short-circuit state, the gate voltage of the third switch Q3 is 12V, the source voltage of the third switch Q3 is 0V, the gate-source voltage VGS of the third switch Q3 is 12V, and the threshold voltage Vth of the third switch Q3 is 7V. At this time, the conduction condition of the third switch Q3 is met and the third switch Q3 is in the on-state. The first resistor R1 and the third resistor R3 participate in voltage division, and the second resistor R2 is used to limit the current, reducing the supply voltage at the positive power supply VLED_INPUT from 12V to 6V, supplying power to the second light-emitting device D2, thereby ensuring normal operation of the second light-emitting device D2 and preventing the second light-emitting device D2 from burning due to overvoltage. When the first light-emitting device D1 is in a short-circuit state, the first switch Q1 is in the off state, and the third switch Q3 is in the on state. The first resistor R1 and the second resistor R2 provide a conduction path for the second light-emitting device D2.

[0110] When the second light-emitting device D2 is in a normal working state, the gate voltage of the fourth switch tube Q4 (connected to the cathode of the second light-emitting device D2) is 0V, the source voltage of the fourth switch tube Q4 (connected to the anode of the second light-emitting device D2) is 6V, the gate-source voltage VGS of the fourth switch tube Q4 is -6V, and the threshold voltage Vth of the fourth switch tube Q4 is 0V. At this time, the turn-on condition of the fourth switch tube Q4 is not met, and the fourth switch tube Q4 is in the off state.

[0111] When the second light-emitting device D2 is short-circuited, the gate voltage of the fourth switch Q4 is 6V, the source voltage of the fourth switch Q4 is 6V, the gate-source voltage VGS of the fourth switch Q4 is 0V, and the threshold voltage Vth of the fourth switch Q4 is 0V. At this point, the conduction condition for the fourth switch Q4 is met, the fourth switch Q4 is in the on-state, and the Zener diode D3 enters a reverse breakdown state (with a critical breakdown voltage less than 6V), clamping the potential of the anode of the second light-emitting device D2 to 6V. This ensures that the voltage drop across the first light-emitting device D1 is the voltage drop required for normal operation, and the first light-emitting device D1 operates normally. When the second light-emitting device D2 is short-circuited, the second switch Q2 is in the off-state, and the fourth switch Q4 is in the on-state. The fourth switch Q4 and the Zener diode D3 provide a conduction path for the first light-emitting device D1.

[0112] The embodiment of the present application further provides a pixel circuit 2, see Figure 5a , the pixel circuit 2 includes the light-emitting device short-circuit protection circuit 1 described in any one of the above embodiments.

[0113] In order to understand the solution of this application more clearly, Figure 5b The pixel circuit structure shown in FIG is used as an example to illustrate. Figure 5b The pixel circuit shown includes: a data writing transistor T1, a driving transistor T2, a compensation transistor T3, a reset transistor T4, a light-emitting control transistor T5, a storage capacitor Cst, a first light-emitting device D1, a second light-emitting device D2, VLED_INPUT is the positive power supply, VLED_OUTPUT is the negative power supply, EM is the light-emitting control signal, Gate(n) is the gate scanning signal line of the current pixel row, Gate(n-1) is the gate scanning signal line of the previous pixel row, Vinit is the reset signal, Reset is the reset control signal, and Data is the data signal line.

[0114] The present application also provides a display substrate 3, see Figure 6 The display substrate 3 includes a plurality of pixel circuits 2 described in the above embodiments.

[0115] The present application also provides a display device 4, see Figure 7 , the display device 4 includes the display substrate 3 described in the above embodiment.

[0116] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0117] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0118] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A short-circuit protection circuit for a light-emitting device, characterized in that: The circuit comprises: A first light-emitting device, a second light-emitting device, a first short-circuit protection module, a second short-circuit protection module, a first voltage control module, and a second voltage control module; the first light-emitting device and the second light-emitting device are connected in series between the positive electrode and the negative electrode of the power supply; The first short-circuit protection module is configured to control the disconnection between the cathode of the first light-emitting device and the anode of the second light-emitting device when the first light-emitting device is in a short-circuit state; The first voltage control module is configured to, when the first light-emitting device is not in a short-circuited state, have its own first switch submodule in an off state, and to work together with the first light-emitting device to control the potential of the anode of the second light-emitting device to a preset voltage value; and, when the first light-emitting device is in a short-circuited state, have its own first switch submodule in an on state, and to control the potential of the anode of the second light-emitting device to a preset voltage value; wherein the preset voltage value is the supply voltage required for the second light-emitting device to operate normally; The second short-circuit protection module is used to control the connection between the cathode of the second light-emitting device and the negative electrode of the power supply to be disconnected when the second light-emitting device is in a short-circuit state; The second voltage control module is used to control the potential of the anode of the second light emitting device to a preset voltage value by turning on the second switch submodule thereof when the second light emitting device is in a short-circuit state.

2. The circuit according to claim 1, wherein: The first voltage control module includes a first switch submodule and a voltage divider submodule; The input end of the voltage divider module is connected to the anode of the first light-emitting device, the first output end of the voltage divider module is connected to the anode of the second light-emitting device, and the second output end of the voltage divider module is connected to the input end of the first switch submodule; the control end of the first switch submodule is connected to the cathode of the first light-emitting device, and the output end of the first switch submodule is connected to the negative electrode of the power supply; The first switch submodule is configured to be in an off state when the first light emitting device is not in a short-circuit state, and to be in an on state when the first light emitting device is in a short-circuit state; The voltage divider submodule is configured to, when the first switch submodule is in the off state, work together with the first light-emitting device to control the potential of the anode of the second light-emitting device to a preset voltage value; When the first switch submodule is in the on state, the potential of the anode of the second light emitting device is controlled to be at a preset voltage value by itself.

3. The circuit according to claim 1, wherein: The second voltage control module includes a voltage stabilizing submodule and a second switch submodule; The control end of the second switch submodule is connected to the cathode of the second light-emitting device, the input end of the second switch submodule is connected to the anode of the second light-emitting device, the output end of the second switch submodule is connected to the first end of the voltage stabilizing submodule; and the second end of the voltage stabilizing submodule is connected to the negative electrode of the power supply; The second switch submodule is configured to be in a conducting state when the second light emitting device is in a short-circuit state, and to be in a shut-off state when the second light emitting device is in a non-short-circuit state; The voltage stabilizing submodule is configured to clamp the potential of the anode of the second light emitting device to a preset voltage value when the second switch submodule is in the on state.

4. The circuit according to claim 1, wherein: The first short-circuit protection module includes a first switching tube; The control electrode of the first switching tube is connected to the anode of the first light-emitting device, the first electrode of the first switching tube is connected to the cathode of the first light-emitting device, and the second electrode of the first switching tube is connected to the anode of the second light-emitting device; The first switch tube is configured to be in a turned-off state when the first light-emitting device is in a short-circuit state, and to be in a turned-on state when the first light-emitting device is in a non-short-circuit state.

5. The circuit according to claim 1, wherein: The second short-circuit protection module includes a second switch tube; The control electrode of the second switch tube is connected to the anode of the second light emitting device, the first electrode of the second switch tube is connected to the cathode of the second light emitting device, and the second electrode of the second switch tube is connected to the negative electrode of the power supply; The second switch tube is configured to be in a turned-off state when the second light emitting device is in a short-circuit state, and to be in a turned-on state when the second light emitting device is in a non-short-circuit state.

6. The circuit according to claim 2, characterized in that The voltage divider submodule includes a first resistor, a second resistor, and a third resistor; the first switch submodule includes a third switch tube; The first electrode of the first resistor is connected to the anode of the first light-emitting device, and the second electrode of the first resistor is connected to the first electrode of the second resistor and the first electrode of the third resistor respectively; the second electrode of the second resistor is connected to the anode of the second light-emitting device; the second electrode of the third resistor is connected to the first electrode of the third switching tube; the control electrode of the third switching tube is connected to the cathode of the first light-emitting device, and the second electrode of the third switching tube is connected to the negative electrode of the power supply.

7. The circuit according to claim 3, characterized in that The second switch submodule includes a fourth switch tube, and the voltage stabilizing submodule includes a voltage stabilizing diode; The control electrode of the fourth switching tube is connected to the cathode of the second light-emitting device, the first electrode of the fourth switching tube is connected to the anode of the second light-emitting device, the second electrode of the fourth switching tube is connected to the cathode of the voltage-stabilizing diode; and the anode of the voltage-stabilizing diode is connected to the negative electrode of the power supply.

8. A pixel circuit, characterized in that: The pixel circuit includes the light emitting device short-circuit protection circuit according to any one of claims 1 to 7.

9. A display substrate, characterized in that: The display substrate includes a plurality of pixel circuits according to claim 8 .

10. A display device, characterized in that: The display device includes the display substrate according to claim 9.

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