A display driving circuit, a display driving method, and a display device.

Abstract

This application discloses a display driving circuit, a display driving method, and a display device, comprising: a grayscale voltage generation circuit; a temperature detection circuit, which outputs a first temperature control signal when the temperature of the display driving chip reaches or exceeds a temperature threshold, wherein the temperature threshold is lower than the junction temperature of the display driving chip; and a grayscale adjustment circuit, which is electrically connected to the temperature detection circuit and receives the first temperature control signal, and is also electrically connected to the grayscale voltage generation circuit and receives the grayscale voltage. When the grayscale adjustment circuit receives the first temperature control signal, it limits the grayscale voltage to a range within the first grayscale voltage threshold. This application, through the temperature detection module and the grayscale control module, can reduce the grayscale voltage when the display driving chip temperature is too high, thereby reducing the temperature of the display driving chip and preventing it from burning out.

Description

Technical Field

[0001] This application relates to the field of displays, and in particular to a display driving circuit and a display device. Background Technology

[0002] In the TV display industry, monitors are evolving towards higher resolutions and refresh rates. With these increases, the data processing capacity of the driver IC on the display increases exponentially, and the heat generated by the driver IC has always been a major challenge for the industry. Currently, the common solution is to add thermal pads to the driver IC. However, if operating in a high-temperature environment and displaying heavy images, the junction temperature inside the driver IC can easily exceed its specifications, causing it to burn out, and in severe cases, even catch fire, resulting in significant losses.

[0003] Therefore, a device is needed that can automatically control the temperature of the display driver chip so that when the operating temperature of the display driver chip exceeds the junction temperature, it can automatically reduce the temperature by lowering the grayscale, thereby preventing the display driver chip from burning out. Summary of the Invention

[0004] The main technical problem this application addresses is the high temperature of the display driver chip.

[0005] To address the aforementioned problems, the first technical solution adopted in this application is to provide a display driving circuit, comprising: a grayscale voltage generation circuit, which generates grayscale voltage to drive a display panel, the grayscale voltage generation circuit being integrated into a display driving chip; a temperature detection circuit, which is connected to the grayscale voltage generation circuit and detects the temperature of the display driving chip; when the temperature detection circuit detects that the temperature of the display driving chip reaches or exceeds a temperature threshold, the temperature detection circuit outputs a first temperature control signal, the temperature threshold being lower than the junction temperature of the display driving chip; and a grayscale adjustment circuit, which is electrically connected to the temperature detection circuit and receives the first temperature control signal, and is also electrically connected to the grayscale voltage generation circuit and receives the grayscale voltage; when the grayscale adjustment circuit receives the first temperature control signal, the grayscale adjustment circuit limits the grayscale voltage to a range within a first grayscale voltage threshold.

[0006] The temperature detection circuit includes: a voltage divider resistor with a fixed resistance value, the input terminal of which is connected to the grayscale voltage generation circuit to provide a constant voltage power supply to the voltage divider resistor; a thermistor connected in series with the voltage divider resistor and positioned close to the display driver chip to detect the temperature of the display driver chip, the thermistor's resistance decreasing as the temperature increases, and the other end of the thermistor grounded; and a first comparator including: a first input terminal connected to the voltage divider node between the voltage divider resistor and the thermistor, and receiving the voltage at the voltage divider node; a second input terminal receiving a first preset voltage; a first comparison unit comparing the voltage at the voltage divider node with the first preset voltage; and a first output terminal comparing the voltage at the voltage divider node with the first preset voltage. If the voltage at the voltage divider node is greater than the first preset voltage, the first output terminal outputs a first temperature control signal; if the voltage at the voltage divider node is less than the first preset voltage, the first output terminal outputs a second temperature control signal.

[0007] The grayscale adjustment circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, and a second comparator. Each transistor has a control terminal, a first terminal, and a second terminal. The control terminal of the first transistor is connected to the first output terminal and receives the first temperature control signal output from the first output terminal. The first transistor conducts after receiving the first temperature control signal. The first terminal of the first transistor is connected to the grayscale voltage generation circuit and receives the grayscale voltage. The second terminal of the first transistor outputs the grayscale voltage input from the first terminal of the first transistor. The second comparator includes a third input terminal, which is connected to the grayscale voltage generation circuit. The second terminal of the first transistor is connected to and receives the grayscale voltage output from the second terminal of the first crystal unit. A fourth input terminal receives the first grayscale threshold voltage. A second comparison unit compares the grayscale voltage input from the third input terminal with the first grayscale threshold voltage input from the fourth input terminal. A second output terminal outputs a first level if the grayscale voltage is greater than the first grayscale threshold voltage, and a second level if the grayscale voltage is less than the first grayscale threshold voltage. The control terminal of the second transistor is connected to the second output terminal and receives either the first level or the second level output from the second output terminal. The first terminal of the second transistor receives the first grayscale threshold voltage; the second transistor conducts when it receives the first level and disconnects when it receives the second level. If the second transistor conducts, the second terminal of the second transistor outputs the first grayscale threshold voltage input to the first terminal of the second transistor. The control terminal of the third transistor is connected in parallel with the control terminal of the second transistor and connected to the second output terminal to receive the first level or the second level input to the second output terminal. The first terminal of the third transistor is connected to the grayscale voltage generation circuit and receives the grayscale voltage. The third transistor disconnects when it receives the first level and conducts when it receives the second level. The second terminal of the third transistor is connected in parallel with the second terminal of the second transistor. If the switching unit of the third transistor is turned on, the second terminal of the third transistor outputs the grayscale voltage. The control terminal of the fourth transistor is connected in parallel with the control terminal of the first transistor and receives the second temperature control signal. The first terminal of the fourth transistor is connected to the grayscale voltage generation circuit and receives the grayscale voltage. When the fourth transistor receives the second temperature control signal, the fourth transistor unit conducts. The second terminal of the fourth transistor outputs the grayscale voltage after the switching unit of the fourth transistor is turned on.

[0008] Wherein, the first transistor is an NMOS transistor, the second transistor is an NMOS transistor, the third transistor is a PMOS transistor, and the fourth transistor is a PMOS transistor.

[0009] The temperature detection circuit further includes: a third comparator, comprising: a fifth input terminal connected to the voltage divider node to receive the voltage of the voltage divider node; a sixth input terminal receiving a second preset voltage, which is less than the first preset voltage; a third comparison unit comparing the voltage of the voltage divider node with the second preset voltage; a third output terminal outputting a high level if the voltage of the voltage divider node is less than the second preset voltage, and a low level if the voltage of the voltage divider node is greater than the second preset voltage; and a fifth transistor, which also has a control terminal, a first terminal, and a second terminal, the control terminal of which is connected to the third output terminal. The first terminal of the fifth transistor is connected to the voltage divider node, and the second terminal of the fifth transistor is connected to the first input terminal of the first comparator. The fifth transistor is a PMOS transistor. The third output terminal is also connected to the grayscale voltage generation circuit. When the grayscale voltage generation circuit receives a high level output from the third output terminal, the grayscale voltage generation circuit is turned off. When the control terminal of the fifth transistor receives a low level output from the third output terminal, the fifth transistor turns on and outputs the voltage of the voltage divider node through the second terminal of the fifth transistor. The first input terminal of the first comparator receives the voltage of the voltage divider node, and the first comparison unit compares the voltage of the voltage divider node with the first preset voltage.

[0010] To address the aforementioned problems, the second technical solution adopted in this application is to provide a display driving method for a display driving circuit. The display driving circuit includes: a grayscale voltage generation circuit, a temperature detection circuit, and a grayscale adjustment circuit. The grayscale voltage generation circuit generates grayscale voltage to drive a display panel. The grayscale voltage generation circuit is integrated into a display driving chip. The temperature detection circuit is connected to the grayscale voltage generation circuit, and the grayscale adjustment circuit is connected to the grayscale voltage generation circuit and receives the grayscale voltage. The display driving method includes: the temperature detection circuit acquiring the temperature of the display driving chip; in response to the temperature of the display driving chip reaching or exceeding a first temperature threshold, the temperature detection circuit outputting a first temperature control signal to the grayscale adjustment circuit; and in response to the first temperature control signal, the grayscale adjustment circuit limiting the grayscale voltage output to within the first grayscale threshold voltage range.

[0011] The temperature detection circuit includes a voltage divider resistor and a thermistor, wherein the thermistor is connected in series with the voltage divider resistor, and a first comparator is connected to the voltage divider node between the voltage divider resistor and the thermistor. The step of the temperature detection circuit outputting a first temperature control signal to the grayscale adjustment circuit in response to the display driver chip's temperature exceeding a first temperature threshold further includes: the first comparator acquiring the voltage at the voltage divider node and determining the magnitude of the voltage at the voltage divider node compared to a first preset voltage; in response to the voltage at the voltage divider node being greater than the first preset voltage, the first comparator outputting the first temperature control signal to the grayscale adjustment circuit; and in response to the voltage at the voltage divider node being less than the first preset voltage, the first comparator outputting a second temperature control signal to the grayscale adjustment circuit.

[0012] The grayscale adjustment circuit includes a first transistor, a second comparator, a third transistor, and a fourth transistor. The first transistor is connected to the first comparator, the second comparator is connected to the first transistor, and the second transistor and the third transistor are connected in parallel and then connected to the second comparator. The step of controlling the grayscale voltage to not exceed a first grayscale voltage threshold in response to the first temperature control signal further includes: in response to the first temperature control signal, the first transistor turns on and outputs the grayscale voltage to the second comparator; the second comparator determines the magnitude of the first grayscale threshold voltage and the absolute value of the grayscale voltage; in response to the grayscale voltage being greater than the first grayscale voltage threshold, the second transistor turns on and outputs the first grayscale threshold voltage, and the third transistor turns off; in response to the grayscale voltage being less than the first grayscale voltage threshold, the second transistor turns off, and the third transistor turns on and outputs the grayscale voltage. The step of the first comparator outputting the second temperature control signal to the grayscale adjustment circuit in response to the voltage at the voltage divider node being less than the first preset voltage further includes: in response to the second temperature control signal, the fourth transistor turns on and outputs the grayscale voltage.

[0013] The circuit includes a third comparator and a fifth transistor, both connected to the voltage divider node, and the fifth transistor connected to the first comparator. The step of the temperature detection circuit acquiring the temperature of the display driver chip further includes: in response to the voltage at the voltage divider node being less than the second preset voltage, the third comparator outputs a high level to the grayscale voltage generation circuit, and the grayscale voltage generation circuit is turned off; in response to the voltage at the voltage divider node being greater than the second preset voltage, the third comparator outputs a low level to the fifth transistor, and the fifth transistor outputs the voltage of the voltage divider node to the first comparator.

[0014] To solve the above problems, the third technical solution adopted in this application is to provide a display device, including: a display driving circuit, wherein the display driving circuit is the display driving circuit in the first technical solution of this application.

[0015] The beneficial effects of this application are: unlike the prior art, by using a temperature detection circuit and a grayscale adjustment circuit, the grayscale voltage output by the display driver chip can be reduced when the operating temperature of the display driver chip is too high, thereby reducing the operating temperature of the display driver chip and preventing the display driver chip from burning out. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the first embodiment of the display driving circuit of this application;

[0017] Figure 2 This is a schematic diagram of the structure of the second embodiment of the display driving circuit of this application;

[0018] Figure 3 This is a schematic diagram of the structure of the third embodiment of the display driving circuit of this application;

[0019] Figure 4 This is a flowchart illustrating the first embodiment of the display driving method of this application;

[0020] Figure 5 This is a flowchart illustrating the second embodiment of the display driving method of this application.

[0021] Marker explanation:

[0022] Display driving circuit 10, grayscale voltage generation circuit 11, temperature detection circuit 12, grayscale adjustment circuit 13;

[0023] Constant voltage power supply VAA1, voltage divider resistor R11, voltage divider resistor R12, voltage divider node R121, temperature voltage U T First comparator A11, first comparison unit A111, first input terminal A112, second input terminal A113, first output terminal A114, first temperature control signal T1, first transistor Q11, first transistor control terminal Q112, first terminal of first transistor Q113, second terminal of first transistor Q114, grayscale voltage U1, second comparator A12, second comparison unit A121, third input terminal A122, fourth input terminal A123, fourth output terminal A124, first grayscale threshold voltage G1, second transistor Q12, second transistor control terminal Q122, first terminal of second transistor Q123, second terminal of second transistor Q124, third transistor Q13, third transistor control terminal Q132, first terminal of third transistor Q133, second terminal of third transistor Q134, grayscale voltage output terminal I31;

[0024] Display driving circuit 20, gray level voltage generation circuit 21, temperature detection circuit 22, gray level adjustment circuit 23;

[0025] Constant voltage power supply VAA2, voltage divider resistors R21 and R22, voltage divider node R221, first comparator A21, first comparator unit A211, first input terminal A212, second input terminal A213, first output terminal A214, first temperature control signal T2, first transistor Q21, control terminal Q212 of the first transistor, first terminal Q213 of the first transistor, second terminal Q214 of the first transistor, grayscale voltage U2, second comparator A22, second comparator unit A221, third input terminal A222. Fourth input terminal A223, second output terminal A224, second transistor Q22, control terminal of second transistor Q222, first terminal of second transistor Q223, second terminal of second transistor Q224, third transistor Q23, control terminal of third transistor Q232, first terminal of third transistor Q233, second terminal of third transistor Q234, fourth transistor Q24, control terminal of fourth transistor Q243, first terminal of fourth transistor Q242, second terminal of fourth transistor Q244, grayscale voltage output terminal 231;

[0026] Display driving circuit 30, grayscale voltage generation circuit 31, temperature detection circuit 32, grayscale adjustment circuit 33;

[0027] Constant voltage power supply VAA3, voltage divider resistor R31, voltage divider resistor R32, voltage divider node R321, first comparator A31, first comparator unit A311, first input terminal A312, second input terminal A313, first output terminal A314, first temperature control signal T3, first transistor Q31, control terminal of the first transistor Q312, first terminal of the first transistor Q313, second terminal of the first transistor Q314, grayscale voltage U3, second comparator A32, second comparator unit A321, third input terminal A322, fourth input terminal A323, second output terminal A324, third comparator A33, third comparator unit A331, fifth input terminal A332, ... The transistor has six input terminals: A333, A334, Q32 (second transistor), Q322 (second transistor control terminal), Q323 (second transistor first terminal), Q324 (second transistor second terminal), Q33 (third transistor), Q332 (third transistor control terminal), Q333 (third transistor first terminal), Q334 (third transistor second terminal), Q343 (fourth transistor), Q343 (fourth transistor control terminal), Q342 (fourth transistor first terminal), Q344 (fourth transistor second terminal), Q355 (fifth transistor control terminal), Q353 (fifth transistor first terminal), Q354 (fifth transistor second terminal), and a grayscale voltage output terminal 331. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0029] The design concept of this application is to set a temperature detection circuit and a grayscale adjustment circuit inside the display driver chip. The temperature detection circuit monitors the temperature of the display driver chip, and when the temperature reaches the junction temperature, the grayscale adjustment circuit limits the grayscale voltage within the range of the first grayscale voltage threshold, thereby reducing the operating temperature of the display driver chip and preventing the display driver chip from overheating.

[0030] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the display driving circuit of this application.

[0031] In this embodiment, the display driving circuit 10 includes: a grayscale voltage generation circuit 11, a temperature detection circuit 12, and a grayscale adjustment circuit 13. The display driving circuit 10 is applied to a display driving chip and integrated within the display driving chip, which generates a grayscale voltage U1 to drive the display panel. The grayscale voltage generation circuit 11 is the circuit in the display driving chip that generates and outputs the grayscale voltage U1.

[0032] In this embodiment, the temperature detection circuit 12 includes: a voltage divider resistor R11, a thermistor R12, and a first comparator A11. The input terminal of the voltage divider resistor R11 is connected to the grayscale voltage generation circuit 12, which provides a constant voltage power supply VAA1 to the voltage divider resistor R11 to enable its normal operation. The resistance value of the voltage divider resistor R11 is a fixed value X1. The thermistor R12 is positioned close to the display driver chip to detect the temperature of the display driver chip. The thermistor R12 is connected in series with the voltage divider resistor R11, and its resistance value X2 decreases as the temperature increases. The output terminal of the thermistor R12 is grounded. It can be understood that as the grayscale voltage U1 increases, the temperature of the display driver chip increases accordingly, and the resistance value of the thermistor R12 decreases accordingly, and the voltage at the voltage divider node 121 also decreases accordingly. That is, the higher the gray level, the higher the internal temperature of the display driver chip, the smaller the resistance of the thermistor R12 in the temperature detection circuit 12, and the smaller the voltage at the voltage divider node 121 between the voltage divider resistor R11 and the thermistor R12.

[0033] In this embodiment, the first comparator A11 has a first input terminal A112, a second input terminal A113, a first comparison unit A11, and a first output terminal A114. The first input terminal A112 is connected to the voltage divider node 121 to detect the temperature voltage U at the voltage divider node. T Voltage divider node 121 is positioned between voltage divider resistor R11 and thermistor R12. The second input terminal A113 receives a first preset voltage, specifically, the value of which is VAA1 / (X1+X2)*X2, where VAA1 is the voltage of the constant voltage power supply, X2 is the resistance of thermistor R12, and X1 is the resistance of voltage divider resistor R11. The first comparison unit A11 compares the voltages input to the first input terminal A112 and the second input terminal A113, that is, it compares the first preset voltage with the temperature voltage U. T The magnitude of the voltage U when the temperature is high T When the absolute value of the voltage is greater than the first preset voltage, the first comparison unit A11 outputs the first temperature control signal T1 through the first output terminal A114.

[0034] In this embodiment, the grayscale adjustment circuit 13 includes: a first transistor Q11, a second comparator A12, a second transistor Q12, and a third transistor Q13.

[0035] In this embodiment, the first transistor Q11 includes: a control terminal Q112, a first terminal Q113, and a second terminal Q114. The control terminal Q112 is connected to the first output terminal A114 and receives the first temperature control signal T1 output by the first output terminal A114. After receiving the first temperature control signal T1, the first transistor Q11 is connected to the circuit. The first terminal Q113 is connected to the grayscale voltage generation circuit 11 and receives the grayscale voltage U1 output by the grayscale voltage generation circuit 11. After the first transistor Q11 is turned on, the second terminal Q114 outputs the grayscale voltage U1.

[0036] In this embodiment, the second comparator A12 includes: a third input terminal A122, a fourth input terminal A123, a second comparison unit A121, and a fourth output terminal A124. The third input terminal A122 is connected to the second terminal Q114 of the first transistor and receives the grayscale voltage U1 output by Q114. The fourth input terminal A123 receives a first grayscale voltage threshold signal G1. The second comparison unit A121 compares the grayscale voltage U1 with the first grayscale voltage threshold signal G1. If the grayscale voltage U1 is larger, a high level is output through the fourth output terminal A124; if the first grayscale voltage threshold signal G1 is larger, a low level is output through the fourth output terminal A124.

[0037] In this embodiment, the second transistor Q12 and the third transistor Q13 are connected in parallel to the fourth output terminal A124. The second transistor Q12 includes: a control terminal Q122, a first terminal Q123, and a second terminal Q124. The third transistor Q13 includes: a control terminal Q132, a first terminal Q133, and a second terminal Q134.

[0038] Specifically, the second output terminal A124 is connected to the control terminals Q122 and Q132 of the second transistor, respectively, meaning that the control terminals Q122 and Q132 of the second and third transistors are connected in parallel. The first terminal Q123 of the second transistor receives the first grayscale voltage threshold signal G1, and the first terminal Q133 of the third transistor is connected to the grayscale voltage generation circuit 11 and receives its output grayscale voltage U1. The control terminals Q122 and Q133 of the second and third transistors are connected in parallel, and the second terminals Q124 and Q134 of the second and third transistors are connected in parallel and connected to the grayscale voltage output terminal 131. When the second output terminal A124 outputs a high level, the second transistor Q12 is turned on, the third transistor Q13 is turned off, and the first grayscale voltage threshold signal G1 is output through the second terminal Q124 of the second transistor and further through the grayscale voltage output terminal 131, serving as the final grayscale voltage output by the display driving circuit 10. When the second output terminal A124 outputs a low level, the second transistor Q12 is turned off, the third transistor Q13 is turned on, and the fifth output terminal Q133 outputs the gray level voltage U1 through the gray level voltage output terminal 131, and uses the gray level voltage U1 as the final gray level voltage output by the display driver circuit 10.

[0039] This embodiment integrates a temperature detection circuit 12 and a grayscale adjustment circuit 13 into the display driver circuit 10. When the display driver chip temperature is detected to be too high, the grayscale voltage output by the display driver circuit 10 is automatically limited to the first grayscale voltage threshold range, which can effectively prevent the operating temperature of the display driver chip from being too high and prevent it from burning out.

[0040] Please see Figure 2 , Figure 2 This is a schematic diagram of the structure of the second embodiment of the display driving circuit of this application.

[0041] In this embodiment, the display driving circuit 20 includes: a grayscale voltage generation circuit 21, a temperature detection circuit 22, and a grayscale adjustment circuit 23.

[0042] In this embodiment, the temperature detection circuit 22 includes: a voltage divider resistor R21, a thermistor R22, and a first comparator A21. The grayscale adjustment circuit 23 includes: a first transistor Q21, a second comparator A22, a second transistor Q22, a third transistor Q23, and a fourth transistor Q24. The grayscale voltage generation circuit 21 provides a constant voltage power supply VAA2 to the temperature detection circuit 22. A voltage divider node 221 is provided between the voltage divider resistor R21 and the thermistor R22. The first comparator A21 includes: a first input terminal 212, a second input terminal A213, a first comparison unit A211, and a first output terminal A214. The first transistor Q21 includes: a control terminal Q212, a first terminal Q213, and a second terminal Q214. The second comparator A221 includes: a third input terminal A222, a fourth input terminal A223, a second output terminal A224, and a second comparison unit A221. The second transistor Q22 includes: a control terminal Q222, a first terminal Q223, and a second terminal Q224. The third transistor Q23 includes: a control terminal Q232, a first terminal Q234, and a second terminal Q233. A grayscale voltage output terminal 231 is also included. The connections and signal transmission relationships between the above components and ports are the same as in the first embodiment of this application, and will not be repeated here.

[0043] Unlike the first embodiment, the grayscale adjustment circuit 23 of this application further includes a fourth transistor Q24, which includes a control terminal Q243, a first terminal Q242, and a second terminal Q244. The control terminal Q243 is connected to the first input terminal A214 of the first comparator A21 to receive the first temperature control signal T2. It is understood that the fourth transistor Q24 is connected in parallel with the first transistor Q21.

[0044] In this embodiment, the first temperature control signal T2 is high when the thermistor R22 detects that the temperature of the display driver chip exceeds the first temperature threshold; and low when the thermistor R22 detects that the temperature of the display driver chip does not exceed the first temperature threshold. When the first temperature control signal T2 is high, the first transistor Q21 is turned on and the fourth transistor Q24 is turned off; when the first temperature control signal T2 is low, the first transistor Q21 is turned off and the fourth transistor Q24 is turned on. The first terminal Q242 of the fourth transistor receives a grayscale voltage U2. The second terminal Q244 of the fourth transistor is connected to the grayscale voltage output terminal 231. When the fourth transistor Q24 is turned on, the second terminal Q244 outputs the grayscale voltage U2 to the grayscale voltage output terminal 231. At this time, the grayscale voltage U2 output by the display driver circuit 20 is the grayscale voltage U2 generated by the grayscale voltage generation circuit 21.

[0045] In this embodiment, the first transistor Q21 is an NMOS transistor, the second transistor Q22 is an NMOS transistor, the third transistor Q23 is a PMOS transistor, and the fourth transistor Q24 is a PMOS transistor.

[0046] In this embodiment, by adding a fourth transistor Q24, the gray level voltage U2 generated by the gray level voltage generation circuit 21 can be output to the gray level voltage output terminal 231 when the temperature has not reached the first temperature threshold.

[0047] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of the third embodiment of the display driving circuit of this application.

[0048] In this embodiment, the grayscale adjustment circuit 33 is the same as that in the second embodiment of the display driving circuit of this application, and will not be described again here. The difference is the temperature detection circuit 32.

[0049] The temperature detection circuit 32 will be described in detail below. The temperature detection circuit 32 includes: a voltage divider resistor R31, a thermistor R32, a third comparator A33, a fifth transistor Q35, and a first comparator A311. A voltage divider node 321 is located between the thermistor R32 and the voltage divider resistor R31. The fifth input terminal A332 of the third comparator A33 is connected to the voltage divider node 321 and receives the voltage at the voltage divider node 321. The sixth input terminal A333 of the third comparator A33 receives a second preset voltage, which can be the voltage corresponding to when the display driver chip reaches the junction temperature. The third output terminal A334 of the third comparator A33 is connected to the grayscale voltage generation circuit 31 and also to the control terminal Q352 of the fifth transistor Q35. The first terminal Q353 of the fifth transistor Q35 is connected to the voltage divider node 321 and receives the voltage from the voltage divider node 321. The second terminal Q354 of the fifth transistor Q35 is connected to the first input terminal A312 of the first comparator A31, and the second input terminal A313 of the first comparator A31 is input with a first preset voltage.

[0050] In this embodiment, the first preset voltage is less than the second preset voltage. The comparison unit A311 of the third comparator A33 compares the second preset voltage with the voltage of the voltage divider node 321. If the second preset voltage is greater than the voltage of the voltage divider node 321, the third output terminal A334 outputs a high level; if the second preset voltage is less than the voltage of the voltage divider node 321, the third output terminal A334 outputs a low level. When the grayscale voltage generation circuit 31 receives the high level output from the third output terminal A334, the grayscale voltage generation circuit 31 shuts down and stops outputting the grayscale voltage U3, further shutting down the display driver circuit 30 and the display driver chip to prevent the display driver chip from burning out. When the control terminal Q352 of the fifth transistor Q35 receives a low level output from the third output terminal A334, the fifth transistor Q35 turns on the circuit and outputs the voltage at the voltage divider node 321 received by the first terminal of the fifth transistor Q35 to the first input terminal A312 of the first comparator A31 through the second terminal Q354 of the fifth transistor Q35. The first input terminal A312 of the first comparator A31 receives the voltage at the voltage divider node 321, and the first comparison unit A311 compares it with a first preset voltage. When the first preset voltage is greater than the voltage at the voltage divider node 321, the first output terminal A314 outputs a second temperature control signal. When the first preset voltage is less than the voltage at the voltage divider node 321, the first output terminal A314 outputs a first temperature control signal.

[0051] This embodiment adds a third comparator A33 and a fifth transistor Q35 to the temperature detection circuit 32, which can directly disconnect the display driver chip when the temperature of the display driver chip reaches the junction temperature, preventing the risk of the display driver chip burning out if the grayscale voltage U3 is limited in time to reduce the temperature of the display driver chip.

[0052] Please see Figure 4 , Figure 4 This is a flowchart illustrating the first embodiment of the display driving method of this application.

[0053] The display driving method of this embodiment is applied to the display driving circuit in the first embodiment of the display driving circuit of this application; by detecting the temperature of the display driving chip, the grayscale voltage output by the display driving chip is automatically adjusted according to the temperature.

[0054] S110: Temperature detection circuit acquires the temperature of the display driver chip;

[0055] In this embodiment, the temperature detection circuit acquires the temperature of the display driver chip. The display driver chip has a display driver circuit and a grayscale voltage generation circuit, which generates grayscale voltage to drive the display panel.

[0056] In this embodiment, the temperature of the display driver chip is obtained to provide a basis for determining whether to perform grayscale voltage adjustment in the future.

[0057] S120: In response to the display driver chip's temperature exceeding the first temperature threshold, the temperature detection circuit outputs a first temperature control signal to the grayscale adjustment circuit.

[0058] In this embodiment, when the temperature detection circuit detects that the temperature of the display driver chip exceeds a first temperature threshold, the temperature detection circuit outputs a first temperature control signal to the grayscale adjustment circuit. The first temperature threshold is lower than the junction temperature of the display driver chip during operation to prevent the display driver chip from burning out. The first temperature control signal is a high-level signal.

[0059] S130: In response to the first temperature control signal, the grayscale adjustment circuit limits the grayscale voltage to the first grayscale threshold range.

[0060] In this embodiment, when the grayscale adjustment circuit receives the first temperature control signal, the grayscale adjustment circuit will limit the grayscale voltage to the range of the first grayscale voltage threshold. That is, when the output grayscale voltage is less than the first grayscale voltage threshold, it will output normally, and when it is greater than the grayscale voltage threshold, the absolute value of the grayscale voltage will be the first grayscale voltage threshold.

[0061] This embodiment automatically limits the grayscale voltage output by the display driver circuit to within the first grayscale voltage threshold range when the temperature of the display driver chip is detected as too high by the temperature detection circuit. This can effectively prevent the operating temperature of the display driver chip from becoming too high and prevent it from burning out.

[0062] Please see Figure 5 , Figure 5 This is a flowchart illustrating the second embodiment of the display driving method of this application.

[0063] The display driving method in this embodiment is applied to the display driving circuit in the second embodiment of the display driving circuit of this application.

[0064] S210: Temperature detection circuit acquires the temperature of the display driver chip;

[0065] In this embodiment, step S210 is the same as step S110 in the first embodiment of the display driving method of this application, and will not be described again here.

[0066] S220: In response to the temperature of the display driver chip reaching or exceeding a first temperature threshold, the first comparator acquires the voltage at the voltage divider node and determines the magnitude of the voltage at the voltage divider node compared with the first preset voltage.

[0067] In this embodiment, when the operating temperature of the display driver chip reaches or exceeds a first temperature threshold, the first comparator acquires the voltage at the voltage divider node. The first temperature threshold is less than the junction temperature of the display driver chip, and the voltage divider node is the node between the voltage divider resistor and the thermistor in the temperature detection circuit. At this time, the voltage at the voltage divider node is compared to a first preset voltage, where the first preset voltage is the voltage at the voltage divider node when the temperature reaches the junction temperature. It can be understood that the higher the temperature of the display driver chip, the lower the voltage of the thermistor, and consequently, the lower the voltage at the voltage divider node.

[0068] S230: In response to the voltage at the voltage divider node being greater than the first preset voltage, the first comparator outputs a first temperature control signal to the grayscale adjustment circuit;

[0069] In this embodiment, step S230 is executed after step S220 determines that the voltage at the voltage divider node is less than the first preset voltage. Since the voltage at the voltage divider node is negatively correlated with the temperature of the display driver chip, when the voltage at the voltage divider node is less than the first preset voltage, it means that the temperature of the display driver chip has reached the first temperature threshold. At this time, the first comparator outputs a first temperature control signal to the grayscale adjustment circuit, wherein the first temperature control signal is a high-level signal.

[0070] S231: In response to the voltage at the voltage divider node being less than the first preset voltage, the first comparator outputs a second temperature control signal to the fourth transistor, the fourth transistor turns on, and outputs a grayscale voltage.

[0071] In this embodiment, step S231 is executed after step S220 determines that the voltage at the voltage divider node is greater than the first preset voltage. When the voltage at the voltage divider node is greater than the first preset voltage, it means that the temperature of the display driver chip is lower than the junction temperature. At this time, the first comparator outputs a second temperature control signal to the fourth transistor, which is connected in parallel with the first transistor. The second temperature control signal is a low-level signal. At this time, the first transistor is turned off, the fourth transistor is turned on, the fourth transistor has a grayscale voltage input, and outputs a grayscale voltage when it is turned on. That is, the grayscale voltage generated by the grayscale voltage generation circuit is not limited and is directly output.

[0072] S240: In response to the first temperature control signal, the first transistor turns on and outputs a grayscale voltage to the second comparator. The second comparator determines the magnitude of the first grayscale threshold voltage and the absolute value of the grayscale voltage.

[0073] In this embodiment, step S240 is executed after step S230. After receiving the first temperature control signal, the first transistor outputs a grayscale voltage to the second comparator. The second comparator also receives a first grayscale threshold voltage and compares the two to determine the magnitude of the first grayscale voltage threshold and the absolute value of the grayscale voltage.

[0074] S250: In response to the grayscale voltage being greater than the first grayscale voltage threshold, the second transistor turns on and outputs the first grayscale voltage threshold, and the third transistor turns off.

[0075] In this embodiment, step S250 is executed after step S240 determines that the grayscale voltage is greater than the first grayscale voltage threshold. When the absolute value of the grayscale voltage is greater than the first grayscale voltage threshold, it means that the grayscale voltage is too high and the output of the grayscale voltage needs to be limited. In this case, the second transistor is turned on, the third transistor is turned off, and the second transistor outputs a grayscale voltage with an absolute value equivalent to the first grayscale voltage threshold.

[0076] This step effectively limits the output value of the grayscale voltage to the range of the first grayscale voltage threshold.

[0077] S251: In response to the grayscale voltage being less than the first grayscale voltage threshold, the second transistor is turned off, the third transistor is turned on and outputs the grayscale voltage;

[0078] In this embodiment, step S251 is executed after step S240 determines that the grayscale voltage is less than the first grayscale voltage threshold. When the absolute value of the grayscale voltage is less than the first grayscale voltage threshold, it means that the current absolute value of the grayscale voltage is low, and there is no need to limit its output. The second transistor is turned off, the third transistor is turned on, and the grayscale voltage is directly output.

[0079] This embodiment obtains the temperature of the display driver chip and automatically limits the grayscale voltage output by the display driver circuit within the first grayscale voltage threshold range when the temperature is too high. This can effectively prevent the operating temperature of the display driver chip from becoming too high and prevent it from burning out.

[0080] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A display drive circuit, characterized by comprising: The display driving circuit includes: A grayscale voltage generation circuit is used to generate grayscale voltage to drive the display panel. The grayscale voltage generation circuit is integrated into a display driver chip. A temperature detection circuit is connected to the grayscale voltage generation circuit and detects the temperature of the display driver chip. When the temperature detection circuit detects that the temperature of the display driver chip reaches or exceeds a temperature threshold, the temperature detection circuit outputs a first temperature control signal. The temperature threshold is lower than the junction temperature of the display driver chip. A grayscale adjustment circuit is electrically connected to the temperature detection circuit and receives the first temperature control signal. The grayscale adjustment circuit is also electrically connected to the grayscale voltage generation circuit and receives the grayscale voltage. When the grayscale adjustment circuit receives the first temperature control signal, the grayscale adjustment circuit limits the grayscale voltage to a first grayscale threshold voltage range and outputs it. The temperature detection circuit includes: A voltage divider resistor with a fixed resistance value is connected to the grayscale voltage generating circuit to provide a constant voltage power supply to the voltage divider resistor. A thermistor is connected in series with the voltage divider resistor and is positioned close to the display driver chip to detect the temperature of the display driver chip. Its resistance decreases as the temperature increases, and the other end of the thermistor is grounded. A first comparator, comprising: The first input terminal is connected to the voltage divider node between the voltage divider resistor and the thermistor, and receives the voltage at the voltage divider node; The second input terminal is supplied with a first preset voltage. The first comparison unit compares the voltage of the voltage divider node with the first preset voltage. At the first output terminal, the first comparison unit compares the voltage of the voltage divider node with the first preset voltage. If the voltage of the voltage divider node is greater than the first preset voltage, the first output terminal outputs the first temperature control signal. If the voltage of the voltage divider node is less than the first preset voltage, the first output terminal outputs the second temperature control signal. The grayscale adjustment circuit includes: a first transistor, a second transistor, a third transistor, a fourth transistor, and a second comparator. Each transistor has a control terminal, a first terminal, and a second terminal. The control terminal of the first transistor is connected to the first output terminal and receives the first temperature control signal output by the first output terminal. The first transistor turns on the circuit after receiving the first temperature control signal. The first terminal of the first transistor is connected to the grayscale voltage generating circuit and receives the grayscale voltage; the second terminal of the first transistor outputs the grayscale voltage input to the first terminal of the first transistor. The second comparator includes: The third input terminal is connected to the second terminal of the first transistor and receives the grayscale voltage output from the second terminal of the first transistor. The fourth input terminal is supplied with the first grayscale threshold voltage; The second comparison unit compares the grayscale voltage input at the third input terminal with the first grayscale threshold voltage input at the fourth input terminal. The second output terminal outputs a first level if the grayscale voltage is greater than the first grayscale threshold voltage, and outputs a second level if the grayscale voltage is less than the first grayscale threshold voltage. The control terminal of the second transistor is connected to the second output terminal and receives the first level or the second level output by the second output terminal. The first terminal of the second transistor is input with the first gray level threshold voltage. When the second transistor receives the first level, the circuit is turned on; when it receives the second level, the circuit is turned off. If the second transistor is turned on, the second terminal of the second transistor outputs the first grayscale threshold voltage input to the first terminal of the second transistor. The control terminal of the third transistor is connected in parallel with the control terminal of the second transistor and is also connected to the second output terminal to receive the first level or the second level input from the second output terminal. The first terminal of the third transistor is connected to the gray level voltage generating circuit and receives the gray level voltage. When the third transistor receives the first level, the circuit is disconnected; when it receives the second level, the circuit is turned on. The second terminal of the third transistor is connected in parallel with the second terminal of the second transistor. If the switching unit of the third transistor is turned on, the second terminal of the third transistor outputs the gray level voltage. The control terminal of the fourth transistor is connected in parallel with the control terminal of the first transistor and receives the second temperature control signal. The first terminal of the fourth transistor is connected to the gray level voltage generating circuit and receives the gray level voltage. When the fourth transistor receives the second temperature control signal, the switching unit of the fourth transistor is turned on. The second terminal of the fourth transistor outputs the grayscale voltage after the switching unit of the fourth transistor is turned on.

2. The display driving circuit according to claim 1, wherein The first transistor is an NMOS transistor, the second transistor is an NMOS transistor, the third transistor is a PMOS transistor, and the fourth transistor is a PMOS transistor.

3. The display driving circuit according to claim 1, characterized in that, The temperature detection circuit also includes: A third comparator, the third comparator comprising: The fifth input terminal is connected to the voltage divider node to receive the voltage of the voltage divider node; The sixth input terminal is supplied with a second preset voltage, which is less than the first preset voltage. The third comparison unit compares the voltage of the voltage divider node with the second preset voltage. The third output terminal outputs a high level if the voltage of the voltage divider node is less than the second preset voltage, and a low level if the voltage of the voltage divider node is greater than the second preset voltage. The fifth transistor also has a control terminal, a first terminal, and a second terminal. The control terminal of the fifth transistor is connected to the third output terminal. The first terminal of the fifth transistor is connected to the voltage divider node. The second terminal of the fifth transistor is connected to the first input terminal of the first comparator. The fifth transistor is a PMOS transistor. The third output terminal is also connected to the grayscale voltage generation circuit. When the grayscale voltage generation circuit receives a high level output from the third output terminal, the grayscale voltage generation circuit is turned off. When the control terminal of the fifth transistor receives a low level output from the third output terminal, the fifth transistor turns on the circuit and outputs the voltage of the voltage divider node through the second terminal of the fifth transistor; The first input terminal of the first comparator receives the voltage of the voltage divider node, and the first comparison unit compares the voltage of the voltage divider node with the first preset voltage.

4. A display driving method applied to a display driving circuit, characterized in that, The display driving circuit includes: a grayscale voltage generation circuit, a temperature detection circuit, and a grayscale adjustment circuit. The grayscale voltage generation circuit generates grayscale voltage to drive the display panel. The grayscale voltage generation circuit is integrated into a display driving chip. The temperature detection circuit is connected to the grayscale voltage generation circuit. The grayscale adjustment circuit is connected to the grayscale voltage generation circuit and receives the grayscale voltage. The temperature detection circuit includes: a voltage divider resistor and a thermistor. The thermistor is connected in series with the voltage divider resistor. A first comparator is connected to the voltage divider node between the voltage divider resistor and the thermistor. The grayscale adjustment circuit includes: a first transistor, a second comparator, a second transistor, a third transistor, and a fourth transistor. The first transistor is connected to the first comparator. The second comparator is connected to the first transistor. The second transistor and the third transistor are connected in parallel and then connected to the second comparator. The display driving method includes: The temperature detection circuit acquires the temperature of the display driver chip; The first comparator acquires the voltage at the voltage divider node and determines the magnitude of the voltage at the voltage divider node compared to a first preset voltage; In response to the voltage at the voltage divider node being greater than a first preset voltage, the first comparator outputs a first temperature control signal to the grayscale adjustment circuit. In response to the voltage at the voltage divider node being less than the first preset voltage, the first comparator outputs a second temperature control signal to the grayscale adjustment circuit. The first comparator acquires the voltage at the voltage divider node and determines the magnitude of the voltage at the voltage divider node compared to a first preset voltage; In response to the voltage at the voltage divider node being greater than the first preset voltage, the first comparator outputs the first temperature control signal to the grayscale adjustment circuit. In response to the voltage at the voltage divider node being less than the first preset voltage, the first comparator outputs a second temperature control signal to the grayscale adjustment circuit.

5. The display driving method according to claim 4, characterized in that, The grayscale adjustment circuit also includes: A third comparator and a fifth transistor, both the fifth transistor and the third comparator being connected to the voltage divider node, and the fifth transistor being connected to the first comparator; The step of the temperature detection circuit acquiring the temperature of the display driver chip further includes: In response to the voltage at the voltage divider node being less than the second preset voltage, the third comparator outputs a high level to the grayscale voltage generation circuit, and the grayscale voltage generation circuit is turned off. In response to the voltage at the voltage divider node being greater than the second preset voltage, the third comparator outputs a low level to the fifth transistor, and the fifth transistor outputs the voltage at the voltage divider node to the first comparator.

6. A display device, characterized in that, It includes a display driving circuit, wherein the display driving circuit is the display driving circuit according to any one of claims 1-3.

Images