Power supply circuit and display device

Abstract

A power supply circuit and a display device, which belong to the technical field of display, and through a positive charge pump circuit, a power supply voltage is connected and converted to output a gate-on voltage; a detection circuit detects the ambient temperature according to the gate-on voltage to output a sampling voltage; a control circuit controls the positive charge pump circuit to convert the power supply voltage according to the sampling voltage; wherein the gate-on voltage is negatively related to the ambient temperature; since the detection circuit detects the ambient temperature according to the gate-on voltage, the gate-on voltage decreases with the increase of the ambient temperature, so the sampling voltage simultaneously detects the gate-on voltage and the ambient temperature, and feeds back the detection result to the gate-on voltage, so that the gate-on voltage changes with the change of the temperature, without setting a higher constant gate-on voltage, realizing the normal opening of the liquid crystal panel in a low temperature environment, and reducing the power consumption.

Description

Technical Field

[0001] This application belongs to the field of display technology, and in particular relates to a power supply circuit and a display device. Background Technology

[0002] Due to the inherent properties of liquid crystal molecules, liquid crystals in LCD panels are difficult to flip at low temperatures, requiring a higher gate turn-on voltage for the liquid crystals to flip normally.

[0003] The existing technology can only generate a constant gate-on voltage through a boost circuit and apply it to the panel. However, this is only a constant voltage value. The panel works normally at room temperature, but in low-temperature environments, due to the characteristics of liquid crystal molecules, it becomes difficult to reverse, resulting in abnormal startup screens. A method of using a higher gate-on voltage is usually employed to achieve the same result. While this method increases the gate-on voltage, allowing the panel to operate normally in low-temperature environments, it also increases overall power consumption; neither can be achieved simultaneously.

[0004] Therefore, the relevant power supply circuit cannot reduce power consumption while turning on the LCD panel normally in a low-temperature environment. Summary of the Invention

[0005] The purpose of this application is to provide a power supply circuit and a display device, which aims to solve the problem that the power supply circuit cannot turn on the LCD panel normally in low temperature environment while reducing power consumption.

[0006] This application provides a power supply circuit, including:

[0007] A positive charge pump circuit is configured to receive a power supply voltage and convert the power supply voltage to output a gate turn-on voltage;

[0008] A detection circuit, connected to the positive charge pump, is configured to detect the ambient temperature based on the gate turn-on voltage and output a sampling voltage.

[0009] A control circuit, connected to the detection circuit and the positive charge pump circuit, is configured to control the positive charge pump circuit to convert the supply voltage according to the sampling voltage;

[0010] The gate turn-on voltage is negatively correlated with the ambient temperature.

[0011] In one embodiment, it further includes:

[0012] A negative charge pump circuit, connected to the control circuit, is configured to receive a reference voltage and convert the reference voltage to output a gate turn-off voltage;

[0013] The control circuit is also configured to control the negative charge pump circuit to convert the reference voltage according to the sampled voltage;

[0014] The gate turn-off voltage is positively correlated with the ambient temperature.

[0015] In one embodiment, the negative charge pump circuit includes a seventh diode, an eighth diode, and a sixth capacitor;

[0016] The first terminal of the sixth capacitor serves as the second drive signal input terminal or the fourth drive signal input terminal of the negative charge pump circuit, and is connected to the control circuit to receive the second drive signal or the fourth drive signal.

[0017] The second terminal of the sixth capacitor is connected to the negative terminal of the seventh diode and the positive terminal of the eighth diode. The negative terminal of the eighth diode serves as the reference voltage input terminal of the negative charge pump circuit, so as to connect to the reference voltage.

[0018] The positive terminal of the seventh diode serves as the gate turn-off voltage output terminal of the negative charge pump circuit to output the gate turn-off voltage.

[0019] In one embodiment, the sampling voltage is positively correlated with the ambient temperature, the sampling voltage is a negative feedback of the gate turn-on voltage, and the sampling voltage is a positive feedback of the gate turn-off voltage.

[0020] In one embodiment, the control circuit includes a first bias power supply chip;

[0021] The positive charge pump circuit drive output terminal of the first bias power supply chip is connected to the positive charge pump circuit as the first drive signal output terminal of the control circuit to output the first drive signal.

[0022] The negative charge pump circuit drive output terminal of the first bias power supply chip is connected to the negative charge pump circuit as the second drive signal output terminal of the control circuit to output the second drive signal.

[0023] The negative charge pump circuit voltage feedback control terminal and the positive charge pump circuit voltage feedback control terminal of the first bias power chip are jointly used as the sampling voltage input terminal of the control circuit and connected to the detection circuit to receive the sampling voltage.

[0024] In one embodiment, the sampling voltage is negatively correlated with the ambient temperature, the sampling voltage is a positive feedback of the gate turn-on voltage, and the sampling voltage is a negative feedback of the gate turn-off voltage.

[0025] In one embodiment, the control circuit includes a second bias power supply chip;

[0026] The negative charge pump circuit drive output terminal of the second bias power supply chip serves as the third drive signal output terminal of the control circuit and is connected to the positive charge pump circuit to output the third drive signal.

[0027] The positive charge pump circuit drive output terminal of the second bias power supply chip is used as the fourth drive signal output terminal of the control circuit and is connected to the negative charge pump circuit to output the fourth drive signal.

[0028] The negative charge pump circuit voltage feedback control terminal and the positive charge pump circuit voltage feedback control terminal of the second bias power supply chip are jointly used as the sampling voltage input terminal of the control circuit and connected to the detection circuit to receive the sampling voltage.

[0029] In one embodiment, the detection circuit includes a thermistor and a first resistor;

[0030] The first end of the thermistor serves as the gate turn-on voltage input terminal of the detection circuit and is connected to the positive charge pump circuit to receive the gate turn-on voltage.

[0031] The second end of the thermistor and the first end of the first resistor together serve as the sampling voltage output terminal of the detection circuit, and are connected to the control circuit to output the sampling voltage;

[0032] The second end of the first resistor is connected to the power supply ground.

[0033] In one embodiment, the positive charge pump circuit includes a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor;

[0034] The first terminal of the first capacitor, the first terminal of the second capacitor, and the first terminal of the third capacitor together serve as the first drive signal input terminal or the third drive signal input terminal of the positive charge pump circuit, and are connected to the control circuit to receive the first drive signal or the third drive signal.

[0035] The second terminal of the first capacitor is connected to the negative terminal of the first diode and the positive terminal of the second diode; the second terminal of the second capacitor is connected to the negative terminal of the third diode and the positive terminal of the fourth diode; and the second terminal of the third capacitor is connected to the negative terminal of the fifth diode and the positive terminal of the sixth diode.

[0036] The positive terminal of the first diode is connected to the power supply voltage. The negative terminal of the second diode is connected to the positive terminal of the third diode and the first terminal of the fourth capacitor. The negative terminal of the fourth diode is connected to the positive terminal of the fifth diode and the first terminal of the fifth capacitor. The second terminal of the fourth capacitor and the second terminal of the fifth capacitor are connected to the power supply ground. The negative terminal of the sixth diode serves as the gate turn-on voltage output terminal of the positive charge pump circuit and is connected to the detection circuit to output the gate turn-on voltage.

[0037] This invention also provides a display device, which includes a display panel and the power supply circuit described above.

[0038] The beneficial effects of the present invention compared with the prior art are as follows: Since the detection circuit detects the ambient temperature based on the gate turn-on voltage, and the gate turn-on voltage is negatively correlated with the ambient temperature, the sampling voltage simultaneously detects both the gate turn-on voltage and the ambient temperature, and feeds the detection result back to the gate turn-on voltage. This enables the gate turn-on voltage to change with temperature, eliminating the need to set a high constant gate turn-on voltage. This allows the LCD panel to be turned on normally in a low-temperature environment while reducing power consumption. Attached Figure Description

[0039] To more clearly illustrate the technical inventions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a power supply circuit provided in an embodiment of this application;

[0041] Figure 2 This is a schematic diagram of another structure of the power supply circuit provided in one embodiment of this application;

[0042] Figure 3 This is a schematic diagram of another structure of the power supply circuit provided in one embodiment of this application;

[0043] Figure 4 This is a schematic diagram of another structure of the power supply circuit provided in one embodiment of this application;

[0044] Figure 5 A partial example circuit schematic diagram of a power supply circuit provided in an embodiment of this application;

[0045] Figure 6 Another example circuit schematic diagram of a power supply circuit provided in an embodiment of this application;

[0046] Figure 7 This is a schematic diagram illustrating the change of gate turn-on voltage with ambient temperature according to an embodiment of this application.

[0047] Figure 8 This is a schematic diagram illustrating the change of gate turn-off voltage with ambient temperature according to an embodiment of this application. Detailed Implementation

[0048] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0049] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0050] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0052] Figure 1 A schematic diagram of the power supply circuit provided in a preferred embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0053] The power supply circuit described above includes a positive charge pump circuit 11, a detection circuit 12, and a control circuit 13.

[0054] The positive charge pump circuit 11 is configured to receive a power supply voltage and convert the power supply voltage to output a gate turn-on voltage; specifically, it can output a gate turn-on voltage to the display panel.

[0055] The detection circuit 12 is connected to the positive charge pump and is configured to detect the ambient temperature based on the gate turn-on voltage and output a sampling voltage.

[0056] The control circuit 13 is connected to the detection circuit 12 and the positive charge pump circuit 11, and is configured to control the positive charge pump circuit 11 to convert the supply voltage according to the sampling voltage;

[0057] Among them, the gate turn-on voltage is negatively correlated with the ambient temperature.

[0058] The positive charge pump circuit 11 converts the supply voltage to output a gate turn-on voltage to the detection circuit 12; the detection circuit 12 detects the ambient temperature based on the gate turn-on voltage and outputs a sampling voltage to the control circuit 13; the control circuit 13 outputs a first drive signal or a third drive signal to the positive charge pump circuit 11 based on the sampling voltage; the positive charge pump circuit 11 then converts the supply voltage based on the first drive signal or the third drive voltage to output the first drive voltage and the third drive voltage after feedback adjustment; thereby establishing a feedback adjustment path for the gate turn-on voltage and a temperature adjustment path.

[0059] like Figure 2 As shown, the power supply circuit also includes a negative charge pump circuit 14.

[0060] The negative charge pump circuit 14 is connected to the control circuit 13 and is configured to receive a reference voltage and convert the reference voltage to output a gate turn-off voltage. Specifically, the gate turn-off voltage can be output to the display panel.

[0061] The control circuit 13 is also configured to control the negative charge pump circuit 14 to convert the reference voltage according to the sampled voltage.

[0062] Among them, the gate turn-off voltage is positively correlated with the ambient temperature.

[0063] The negative charge pump circuit 14 converts the reference voltage to output the gate turn-off voltage; the control circuit 13 outputs a second drive signal or a fourth drive signal according to the sampled voltage; the positive charge pump circuit 11 then converts the reference voltage according to the second drive signal or the fourth drive signal to output the second drive signal or the fourth drive signal after feedback adjustment; thereby establishing the feedback adjustment path of the gate turn-off voltage and the temperature adjustment path.

[0064] As an example and not a limitation, the sampling voltage is positively correlated with the ambient temperature, the sampling voltage is a negative feedback of the gate turn-on voltage, and the sampling voltage is a positive feedback of the gate turn-off voltage.

[0065] In specific implementation, the positive charge pump circuit 11 converts the supply voltage to output a gate turn-on voltage to the detection circuit 12; the detection circuit 12 detects the ambient temperature based on the gate turn-on voltage and outputs a sampling voltage to the control circuit 13; the control circuit 13 outputs a first drive signal based on the sampling voltage; the positive charge pump circuit 11 then converts the supply voltage based on the first drive signal to output a first drive voltage after feedback adjustment; the duty cycle and / or the level of the first drive signal decrease as the sampling voltage increases; the gate turn-on voltage decreases as the duty cycle and / or the level of the first drive signal decreases; thereby establishing a feedback adjustment path for the gate turn-on voltage and a temperature adjustment path.

[0066] The negative charge pump circuit 14 converts the reference voltage to output a gate turn-off voltage; the control circuit 13 outputs a second drive signal based on the sampled voltage; the positive charge pump circuit 11 then converts the reference voltage based on the second drive signal to output a second drive signal after feedback adjustment; the duty cycle and / or the level of the second drive signal increase with the increase of the sampled voltage; the gate turn-off voltage increases with the increase of the duty cycle and / or the level of the second drive signal; thereby establishing a feedback adjustment path for the gate turn-off voltage and a temperature adjustment path.

[0067] As an example and not a limitation, the sampling voltage is negatively correlated with the ambient temperature, the sampling voltage is a positive feedback of the gate turn-on voltage, and the sampling voltage is a negative feedback of the gate turn-off voltage.

[0068] In specific implementation, the positive charge pump circuit 11 converts the supply voltage to output the gate turn-on voltage; the control circuit 13 outputs a third drive signal according to the sampled voltage; the positive charge pump circuit 11 then converts the supply voltage according to the third drive signal to output the third drive voltage after feedback adjustment; the duty cycle and / or the level of the third drive signal increase with the increase of the sampled voltage; the gate turn-on voltage increases with the increase of the duty cycle and / or the level of the third drive signal; thereby establishing a temperature regulation path for the gate turn-on voltage.

[0069] The negative charge pump circuit 14 converts the reference voltage to output the gate turn-off voltage; the control circuit 13 outputs a fourth drive signal according to the sampled voltage; the positive charge pump circuit 11 then converts the reference voltage according to the fourth drive signal to output the fourth drive signal after feedback adjustment; the duty cycle and / or the level of the fourth drive signal decrease as the sampled voltage increases; the gate turn-off voltage decreases as the duty cycle and / or the level of the second drive signal decreases; thereby establishing a temperature regulation path for the gate turn-off voltage.

[0070] like Figure 3As shown, the power supply circuit also includes a first clamping circuit 15.

[0071] The first clamping circuit 15 is connected to the control circuit 13, the positive charge pump circuit 11 and the detection circuit 12, and is configured to clamp the gate turn-on voltage.

[0072] By clamping the gate turn-on voltage, damage to the LCD screen is prevented due to excessive gate turn-on voltage, thus improving the reliability and stability of the system.

[0073] like Figure 4 As shown, the power supply circuit also includes a second clamping circuit 16.

[0074] The second clamping circuit 16 is connected to the negative charge pump circuit 14 and is configured to clamp the gate turn-off voltage.

[0075] By clamping the gate turn-off voltage, damage to the LCD screen is prevented due to excessive gate turn-off voltage, thus improving the reliability and stability of the system.

[0076] Figure 5 This invention illustrates a partial example circuit structure of a power supply circuit provided in an embodiment of the present invention. Figure 6 The following is a partial example circuit structure of the power supply circuit provided in an embodiment of the present invention. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0077] like Figure 5 As shown, the control circuit 13 includes a first bias power supply chip U1.

[0078] The positive charge pump circuit 11 of the first bias power supply chip U1 has a drive output terminal DRVP, which serves as the first drive signal output terminal of the control circuit 13 and is connected to the positive charge pump circuit 11 to output a first drive signal. The negative charge pump circuit 14 of the first bias power supply chip U1 has a drive output terminal DRVN, which serves as the second drive signal output terminal of the control circuit 13 and is connected to the negative charge pump circuit 14 to output a second drive signal. The voltage feedback control terminal FBN of the negative charge pump circuit 14 and the voltage feedback control terminal FBP of the positive charge pump circuit 11 of the first bias power supply chip U1 together serve as the sampling voltage input terminal of the control circuit 13 and are connected to the detection circuit 12 to receive the sampling voltage. Specifically, the voltage feedback control terminal FBN of the negative charge pump circuit 14 and the voltage feedback control terminal FBP of the positive charge pump circuit 11 of the first bias power supply chip U1 are connected to a first node, which serves as the sampling voltage input terminal of the control circuit 13 and is connected to the detection circuit 12 to receive the sampling voltage.

[0079] Using a bias power supply chip as the control circuit 13 results in a simple circuit with low cost.

[0080] like Figure 6 As shown, the control circuit 13 includes a second bias power supply chip U2.

[0081] The negative charge pump circuit 14 of the second bias power chip U2 has a drive output terminal DRVN, which serves as the third drive signal output terminal of the control circuit 13 and is connected to the positive charge pump circuit 11 to output the third drive signal. The positive charge pump circuit 11 of the second bias power chip U2 has a drive output terminal DRVP, which serves as the fourth drive signal output terminal of the control circuit 13 and is connected to the negative charge pump circuit 14 to output the fourth drive signal. The voltage feedback control terminal FBN of the negative charge pump circuit 14 of the second bias power chip U2 and the voltage feedback control terminal FBP of the positive charge pump circuit 11 of the second bias power chip U2 together serve as the sampling voltage input terminal of the control circuit 13 and are connected to the detection circuit 12 to receive the sampling voltage. Specifically, the voltage feedback control terminal FBN of the negative charge pump circuit 14 of the second bias power chip U2 and the voltage feedback control terminal FBP of the positive charge pump circuit 11 of the second bias power chip U2 are connected to the second node, which serves as the sampling voltage input terminal of the control circuit 13 and is connected to the detection circuit 12 to receive the sampling voltage.

[0082] Using a bias power supply chip as the control circuit 13 results in a simple circuit with low cost.

[0083] like Figure 5 and Figure 6 As shown, the detection circuit 12 includes a thermistor RT and a first resistor R1.

[0084] The first end of the thermistor RT serves as the gate turn-on voltage input terminal of the detection circuit 12 and is connected to the positive charge pump circuit 11 to receive the gate turn-on voltage; the second end of the thermistor RT and the first end of the first resistor R1 together serve as the sampling voltage output terminal of the detection circuit 12 and are connected to the control circuit 13 to output the sampling voltage; the second end of the first resistor R1 is connected to the power supply ground.

[0085] It should be noted that, in Figure 3 In this context, the thermistor RT has a negative temperature coefficient; Figure 4 In this context, the thermistor RT has a positive temperature coefficient.

[0086] The detection circuit 12 is simple and reliable.

[0087] like Figure 5 and Figure 6 As shown, the positive charge pump circuit 11 includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, a sixth diode D6, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, and a fifth capacitor C5.

[0088] The first terminals of the first capacitor C1, the second capacitor C2, and the third capacitor C3 together serve as either the first or third drive signal input terminal of the positive charge pump circuit 11, connected to the control circuit 13 to receive the first or third drive signal. The second terminal of the first capacitor C1 is connected to the cathode of the first diode D1 and the anode of the second diode D2. The second terminal of the second capacitor C2 is connected to the cathode of the third diode D3 and the anode of the fourth diode D4. The second terminal of the third capacitor C3 is connected to the cathode of the fifth diode D4 and the cathode of the second diode D5. The negative terminal of diode D5 is connected to the positive terminal of the sixth diode D6; the positive terminal of the first diode D1 is connected to the power supply voltage; the negative terminal of the second diode D2 is connected to the positive terminal of the third diode D3 and the first terminal of the fourth capacitor C4; the negative terminal of the fourth diode D4 is connected to the positive terminal of the fifth diode D5 and the first terminal of the fifth capacitor C5; the second terminals of the fourth capacitor C4 and the second terminals of the fifth capacitor C5 are connected to the power supply ground; the negative terminal of the sixth diode D6 serves as the gate turn-on voltage output terminal of the positive charge pump circuit 11 and is connected to the detection circuit 12 to output the gate turn-on voltage.

[0089] The positive charge pump circuit 11 described above achieves a three-stage voltage boost, enhancing the voltage boost capability.

[0090] like Figure 5 and Figure 6 As shown, the negative charge pump circuit 14 includes a seventh diode D7, an eighth diode D8, and a sixth capacitor C6.

[0091] The first terminal of the sixth capacitor C6 serves as the second or fourth drive signal input terminal of the negative charge pump circuit 14, and is connected to the control circuit 13 to receive the second or fourth drive signal. The second terminal of the sixth capacitor C6 is connected to the negative terminal of the seventh diode D7 and the positive terminal of the eighth diode D8. The negative terminal of the eighth diode D8 serves as the reference voltage input terminal of the negative charge pump circuit 14 to receive the reference voltage. The positive terminal of the seventh diode D7 serves as the gate turn-off voltage output terminal of the negative charge pump circuit 14 to output the gate turn-off voltage.

[0092] It should be noted that the reference voltage can be the power supply ground, which simplifies the circuit.

[0093] The following is based on the working principle. Figure 5 Further explanation is provided below:

[0094] A positive charge pump circuit 11, comprising diodes D1 to D6 and capacitors C1 to C5, converts the supply voltage VBB to output a gate turn-on voltage. A negative charge pump circuit 14, comprising diodes D7, D8, and C6, converts a reference voltage to output a gate turn-off voltage. A negative temperature coefficient thermistor RT and resistor R1 detect the gate turn-on voltage and output a sampling voltage; therefore, the sampling voltage increases with increasing temperature. The first bias power supply chip U1 outputs a first drive signal from the positive charge pump circuit 11 drive output terminal DRVP based on the sampling voltage, and outputs a second drive signal from the negative charge pump circuit 14 drive output terminal DRVN based on the sampling voltage. The duty cycle and / or level of the first drive signal decrease as the sampling voltage increases; the duty cycle and / or level of the second drive signal increase as the sampling voltage increases. The positive charge pump circuit 11 converts the supply voltage according to the first drive signal to output a feedback-regulated gate turn-on voltage; wherein, the feedback-regulated gate turn-on voltage decreases as the duty cycle and / or level of the first drive signal decreases. The positive charge pump circuit 11 converts the reference voltage according to the second drive signal to output a feedback-regulated gate turn-off voltage; wherein, the feedback-regulated gate turn-off voltage increases as the duty cycle and / or level of the second drive signal increases. This achieves a situation where the gate turn-on voltage decreases with increasing temperature, and the gate turn-off voltage increases with increasing temperature.

[0095] In practical applications, a second resistor R2 can be connected in parallel to the thermistor RT, and then the first resistor R1 can be connected in series. This allows for different temperature compensation curves to be achieved by changing the resistance values ​​of the first resistor R1 and the second resistor R2, thus expanding the application range. The following is an application example: a 47KΩ negative temperature coefficient thermistor RT is selected, with a 10KΩ first resistor R1 and a 90KΩ second resistor R2, both with a resistance accuracy of 1%. The target temperature range is 10℃ to 20℃. As the temperature decreases, the gate turn-on voltage VGH begins to rise, reaching a maximum of 35V at -20℃. The negative feedback system is set such that for every 1V increase in the gate turn-on voltage VGH, the gate turn-off voltage VGL decreases by 0.8V. The actual temperature compensation curve is basically consistent with the theoretical curve. A schematic diagram of the gate turn-on voltage changing with ambient temperature is shown below. Figure 7 As shown in the diagram, the gate turn-off voltage varies with ambient temperature. Figure 8 As shown.

[0096] The following is based on the working principle. Figure 6 Further explanation is provided below:

[0097] A positive charge pump circuit 11, comprising diodes D1 to D6 and capacitors C1 to C5, converts the supply voltage VBB to output a gate turn-on voltage. A negative charge pump circuit 14, comprising diodes D7, D8, and C6, converts a reference voltage to output a gate turn-off voltage. A thermistor RT with a positive temperature coefficient and resistor R1 detect the gate turn-on voltage and output a sampling voltage; therefore, the sampling voltage decreases as the temperature increases. The second bias power supply chip U2 outputs a third drive signal from the negative charge pump circuit 14's drive output terminal DRVN based on the sampling voltage, and outputs a fourth drive signal from the positive charge pump circuit 11's drive output terminal DRVP based on the sampling voltage. The duty cycle and / or level of the third drive signal increase with increasing sampling voltage; the duty cycle and / or level of the fourth drive signal decrease with increasing sampling voltage. The positive charge pump circuit 11 converts the supply voltage according to the third drive signal to output a feedback-regulated gate turn-on voltage; wherein, the feedback-regulated gate turn-on voltage increases with the increase of the duty cycle and / or the level of the third drive signal. The negative charge pump circuit 14 converts the reference voltage according to the fourth drive signal to output a feedback-regulated gate turn-off voltage; wherein, the feedback-regulated gate turn-off voltage decreases with the decrease of the duty cycle and / or the level of the fourth drive signal. This achieves a situation where the gate turn-on voltage decreases with increasing temperature, and the gate turn-off voltage increases with increasing temperature.

[0098] This invention also provides a display device, which includes the power supply circuit described above.

[0099] In practice, display devices may include LCD screens, laptops, and LCD TVs.

[0100] This invention utilizes a positive charge pump circuit to connect to the power supply voltage and convert it to output a gate turn-on voltage. A detection circuit monitors the ambient temperature based on the gate turn-on voltage and outputs a sampling voltage. A control circuit controls the positive charge pump circuit to convert the power supply voltage based on the sampling voltage. The gate turn-on voltage decreases as the ambient temperature increases. Since the detection circuit monitors the ambient temperature based on the gate turn-on voltage, and the gate turn-on voltage is negatively correlated with the ambient temperature, the sampling voltage simultaneously detects both the gate turn-on voltage and the ambient temperature, feeding the detection result back to the gate turn-on voltage. This allows the gate turn-on voltage to change with temperature, eliminating the need for a high, constant gate turn-on voltage. This enables normal operation of the LCD panel in low-temperature environments while reducing power consumption. This application achieves normal operation of the LCD panel in low-temperature environments without the need for a temperature compensation chip, reducing hardware costs.

[0101] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A power supply circuit, characterized in that, include: A positive charge pump circuit is configured to receive a power supply voltage and convert the power supply voltage to output a gate turn-on voltage; A detection circuit, connected to the positive charge pump, is configured to detect the ambient temperature based on the gate turn-on voltage and output a sampling voltage. A control circuit, connected to the detection circuit and the positive charge pump circuit, is configured to control the positive charge pump circuit to convert the supply voltage according to the sampling voltage; The gate turn-on voltage is negatively correlated with the ambient temperature. A negative charge pump circuit, connected to the control circuit, is configured to receive a reference voltage and convert the reference voltage to output a gate turn-off voltage; The control circuit is also configured to control the negative charge pump circuit to convert the reference voltage according to the sampled voltage; The gate turn-off voltage is positively correlated with the ambient temperature.

2. The power supply circuit as described in claim 1, characterized in that, The negative charge pump circuit includes a seventh diode, an eighth diode, and a sixth capacitor; The first terminal of the sixth capacitor serves as the second drive signal input terminal or the fourth drive signal input terminal of the negative charge pump circuit, and is connected to the control circuit to receive the second drive signal or the fourth drive signal. The second terminal of the sixth capacitor is connected to the negative terminal of the seventh diode and the positive terminal of the eighth diode. The negative terminal of the eighth diode serves as the reference voltage input terminal of the negative charge pump circuit, so as to connect to the reference voltage. The positive terminal of the seventh diode serves as the gate turn-off voltage output terminal of the negative charge pump circuit to output the gate turn-off voltage.

3. The power supply circuit as described in claim 1, characterized in that, The sampling voltage is positively correlated with the ambient temperature, the sampling voltage is a negative feedback of the gate turn-on voltage, and the sampling voltage is a positive feedback of the gate turn-off voltage.

4. The power supply circuit as described in claim 3, characterized in that, The control circuit includes a first bias power supply chip; The positive charge pump circuit drive output terminal of the first bias power supply chip is connected to the positive charge pump circuit as the first drive signal output terminal of the control circuit to output the first drive signal. The negative charge pump circuit drive output terminal of the first bias power supply chip is connected to the negative charge pump circuit as the second drive signal output terminal of the control circuit to output the second drive signal. The negative charge pump circuit voltage feedback control terminal and the positive charge pump circuit voltage feedback control terminal of the first bias power chip are jointly used as the sampling voltage input terminal of the control circuit and connected to the detection circuit to receive the sampling voltage.

5. The power supply circuit as described in claim 1, characterized in that, The sampling voltage is negatively correlated with the ambient temperature, the sampling voltage is a positive feedback of the gate turn-on voltage, and the sampling voltage is a negative feedback of the gate turn-off voltage.

6. The power supply circuit as described in claim 5, characterized in that, The control circuit includes a second bias power supply chip; The negative charge pump circuit drive output terminal of the second bias power supply chip serves as the third drive signal output terminal of the control circuit and is connected to the positive charge pump circuit to output the third drive signal. The positive charge pump circuit drive output terminal of the second bias power supply chip is used as the fourth drive signal output terminal of the control circuit and is connected to the negative charge pump circuit to output the fourth drive signal. The negative charge pump circuit voltage feedback control terminal and the positive charge pump circuit voltage feedback control terminal of the second bias power supply chip are jointly used as the sampling voltage input terminal of the control circuit and connected to the detection circuit to receive the sampling voltage.

7. The power supply circuit as described in any one of claims 1 to 6, characterized in that, The detection circuit includes a thermistor and a first resistor; The first end of the thermistor serves as the gate turn-on voltage input terminal of the detection circuit and is connected to the positive charge pump circuit to receive the gate turn-on voltage. The second end of the thermistor and the first end of the first resistor together serve as the sampling voltage output terminal of the detection circuit, and are connected to the control circuit to output the sampling voltage; The second end of the first resistor is connected to the power supply ground.

8. The power supply circuit according to any one of claims 1 to 6, characterized in that, The positive charge pump circuit includes a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, and a fifth capacitor; The first terminal of the first capacitor, the first terminal of the second capacitor, and the first terminal of the third capacitor together serve as the first drive signal input terminal or the third drive signal input terminal of the positive charge pump circuit, and are connected to the control circuit to receive the first drive signal or the third drive signal. The second terminal of the first capacitor is connected to the negative terminal of the first diode and the positive terminal of the second diode; the second terminal of the second capacitor is connected to the negative terminal of the third diode and the positive terminal of the fourth diode; and the second terminal of the third capacitor is connected to the negative terminal of the fifth diode and the positive terminal of the sixth diode. The positive terminal of the first diode is connected to the power supply voltage. The negative terminal of the second diode is connected to the positive terminal of the third diode and the first terminal of the fourth capacitor. The negative terminal of the fourth diode is connected to the positive terminal of the fifth diode and the first terminal of the fifth capacitor. The second terminal of the fourth capacitor and the second terminal of the fifth capacitor are connected to the power supply ground. The negative terminal of the sixth diode serves as the gate turn-on voltage output terminal of the positive charge pump circuit and is connected to the detection circuit to output the gate turn-on voltage.

9. A display device, characterized in that, The display device includes a display panel and a power supply circuit as described in any one of claims 1 to 8.

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