Driving circuit of display panel and display device

Abstract

This invention proposes a driving circuit and display device for a display panel. The driving circuit of the display panel includes a gate driving circuit and an impedance adjustment circuit. The impedance adjustment circuit adjusts its own impedance to a target impedance according to the current ambient temperature. The target impedance is different at different temperatures. The target impedance and the equivalent impedance of the gate driving circuit form the total impedance. The total impedance is equal at different ambient temperatures. Correspondingly, the on-current and off-current output by the gate driving circuit remain the same, that is, they have the same driving capability, which ensures the driving effect and display effect of the display panel and achieves display consistency. Furthermore, the impedance adjustment circuit adaptively adjusts its own impedance according to the ambient temperature, which improves the compensation timeliness.

Description

Technical Field

[0001] This invention belongs to the field of display panel technology, and particularly relates to a driving circuit and display device for a display panel. Background Technology

[0002] With the current development of display technology, there is a pursuit of clearer and higher quality product display performance. In addition, the requirements for environmental verification of display devices are also constantly increasing.

[0003] The display panel is driven by a corresponding display panel driving circuit. The display panel driving circuit may include a corresponding source driving circuit and a gate driving circuit. The gate driving circuit provides a horizontal scanning signal to the display panel, and the source driving circuit provides a data signal of a corresponding size to the display panel. The display panel displays the corresponding image information under the drive of the data signal and the horizontal scanning signal.

[0004] The gate drive circuit is composed of amorphous silicon thin-film transistors. The mobility of amorphous silicon thin-film transistors varies greatly with temperature. At high temperatures, the electron mobility is high and the current is large, while at low temperatures, the electron mobility is low and the current is small. In the gate drive circuit, this means that the on-current and off-current are smaller at low temperatures, and the overall equivalent impedance of the gate drive circuit is larger than at room temperature. At high temperatures, the on-current and off-current are larger, and the overall equivalent impedance of the gate drive circuit is smaller than at room temperature. This results in different driving capabilities of the gate drive circuit, which in turn causes abnormalities in the display panel.

[0005] To address this issue, a conventional drive compensation method involves setting up a compensation circuit that detects the temperature and provides a compensation current at the output of the gate drive circuit to achieve current compensation and thus ensure consistent drive capability.

[0006] However, the method of detecting ambient temperature and compensating for current has a compensation lag. It requires detection before compensation, and the compensation effect is not good. Especially when the power is turned on, the gate drive circuit has already output the corresponding row scan signal, but the compensation circuit has not yet performed compensation, resulting in abnormal display when the power is turned on. Summary of the Invention

[0007] The purpose of this invention is to provide a driving circuit for a display panel, which aims to solve the problem of poor compensation effect in traditional compensation circuits.

[0008] A first aspect of this invention provides a driving circuit for a display panel, comprising:

[0009] A gate driving circuit is connected to multiple scan lines of the display panel. The gate driving circuit is used to output a row scan signal to the display panel according to the gate driving signal.

[0010] An impedance adjustment circuit is connected to the gate drive circuit and conducts the gate drive signal. The impedance adjustment circuit is used to adjust its own impedance to a target impedance according to the ambient temperature, so that the total impedance of the target impedance and the equivalent impedance of the gate drive circuit is equal at different ambient temperatures.

[0011] Optionally, the impedance adjustment circuit is connected in series at the input terminal of the gate drive circuit, and the impedance adjustment circuit is used to receive and transmit the gate drive signal to the gate drive circuit.

[0012] The impedance adjustment circuit is used to adjust its own impedance in a positive correlation with the ambient temperature.

[0013] Optionally, the impedance adjustment circuit includes:

[0014] An impedance output circuit is connected in series with the input terminal of the gate drive circuit. The impedance output circuit is used to switch the output impedance to different impedances corresponding to the positive change of ambient temperature according to the impedance switching signal.

[0015] Temperature sensing circuit, used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature;

[0016] The comparison circuit is connected to the impedance output circuit and the temperature sensing circuit respectively. The comparison circuit is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

[0017] Optionally, the impedance output circuit includes multiple impedance units connected in series, each impedance unit including a switching switch and a resistor connected in parallel, the switching switch being connected to the comparison circuit respectively.

[0018] Optionally, the impedance adjustment circuit is connected in parallel to the input and output terminals of the gate drive circuit;

[0019] The impedance adjustment circuit is used to adjust its own impedance in a positive correlation with the ambient temperature.

[0020] Optionally, the impedance adjustment circuit includes:

[0021] An impedance output circuit is connected in parallel to the input and output terminals of the gate drive circuit. The impedance output circuit is used to switch the output impedance to different impedances corresponding to the positive correlation change of the ambient temperature according to the impedance switching signal.

[0022] Temperature sensing circuit, used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature;

[0023] The comparison circuit is connected to the impedance output circuit and the temperature sensing circuit respectively. The comparison circuit is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

[0024] Optionally, the impedance output circuit includes multiple impedance units connected in parallel, each impedance unit including a switching switch and a resistor connected in series, the switching switch being connected to the comparison circuit respectively.

[0025] Optionally, the comparison circuit includes multiple comparators. The inverting input terminal of the comparator is used to input the temperature sensing signal, and the non-inverting input terminal of the comparator is used to input a reference voltage. The output terminals of the multiple comparators are connected to the control terminals of the multiple switching switches one by one, and each comparator corresponds to a different reference voltage.

[0026] Optionally, the temperature sensing circuit includes a thermistor and a voltage divider resistor;

[0027] The first end of the thermistor is connected to the positive voltage terminal, and the second end of the thermistor and the first end of the voltage divider resistor are connected to form the output terminal of the temperature sensing circuit. The second end of the voltage divider resistor is grounded.

[0028] A second aspect of the present invention provides a display device, including a display panel and a driving circuit for the display panel as described above, wherein the driving circuit for the display panel is connected to the display panel.

[0029] The beneficial effects of the present invention embodiments compared with the prior art are as follows: The driving circuit of the above-mentioned display panel includes a gate driving circuit and an impedance adjustment circuit. The impedance adjustment circuit adjusts its own impedance to the target impedance according to the current ambient temperature. The target impedance is different at different temperatures. The target impedance and the equivalent impedance of the gate driving circuit form the total impedance. The total impedance is equal at different ambient temperatures. Correspondingly, the on-current and off-current output by the gate driving circuit remain the same, that is, it has the same driving capability, which ensures the driving effect and display effect of the display panel, realizes display consistency, and the impedance adjustment circuit adaptively adjusts its own impedance according to the ambient temperature, which improves the compensation timeliness. Attached Figure Description

[0030] Figure 1 The diagram shows the driving circuit and the structure of the display panel provided in Embodiments 1 and 2 of the present invention.

[0031] Figure 2 The diagram shows the driving circuit and the structure of the display panel provided in Embodiments 1 and 3 of the present invention.

[0032] Figure 3This is a schematic diagram of the driving circuit for the display panel provided in Embodiment 2 of the present invention;

[0033] Figure 4 This is a circuit diagram of the driving circuit for the display panel provided in Embodiment 2 of the present invention;

[0034] Figure 5 This is a schematic diagram of the driving circuit for the display panel provided in Embodiment 3 of the present invention;

[0035] Figure 6 This is a circuit diagram of the driving circuit for the display panel provided in Embodiment 3 of the present invention;

[0036] Figure 7 This is a schematic diagram of the structure of the display device provided in Embodiment 4 of the present invention.

[0037] The figures in the diagram are labeled as follows:

[0038] 100. Display panel; 200. Driving circuit for display panel; 110. Display area; 120. Non-display area; 210. Gate driving circuit; 220. Impedance adjustment circuit; 230. Driver chip; 221. Impedance output circuit; 222. Temperature sensing circuit; 223. Comparison circuit;

[0039] NTC, thermistor; R1, voltage divider resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; Rx1, first sub-resistor; Rx2, second sub-resistor; K1, first switching switch; K2, second switching switch; VCC, positive voltage terminal. Detailed Implementation

[0040] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0041] 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 invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0042] Example 1

[0043] A first aspect of the present invention provides a driving circuit 200 for a display panel.

[0044] like Figure 1 or Figure 2 As shown, in this embodiment, the driving circuit 200 of the display panel includes:

[0045] The gate driving circuit 210 is connected to multiple scan lines of the display panel 100. The gate driving circuit 210 is used to output a row scan signal to the display panel 100 according to the gate driving signal.

[0046] Impedance adjustment circuit 220 is connected to gate drive circuit 210 and conducts gate drive signal. Impedance adjustment circuit 220 is used to adjust its own impedance to target impedance according to ambient temperature so that the total impedance of target impedance and equivalent impedance of gate drive circuit 210 is equal at different ambient temperatures.

[0047] In this embodiment, the display panel 100 includes a display area 110 and a non-display area 120. The display area 110 is provided with multiple rows of scan lines, multiple columns of data lines, and pixel units arranged in an array. Each pixel unit is connected to a data line and a scan line. The driving circuit 200 of the display panel is located in the non-display area 120. The data lines and scan lines of the display area 110 extend to the non-display area 120 and are connected to the driving circuit 200 of the display panel. The driving circuit 200 of the display panel provides corresponding data signals and row scan signals. The pixel units display corresponding image information according to the received data signals and row scan signals.

[0048] The driving circuit 200 of the display panel includes a gate driving circuit 210 and an impedance adjustment circuit 220. The driving circuit 200 of the display panel also includes a driving chip 230. The driving chip 230 provides a gate driving signal to the gate driving circuit 210. The driving chip 230 is also connected to multiple columns of data lines and provides data signals. The gate driving circuit 210 is connected to multiple rows of scan lines. The gate driving circuit 210 outputs a row scan signal line by line in each frame according to the received gate driving signal and drives the pixel units to turn on line by line, thereby realizing the line-by-line driving display.

[0049] The electron mobility of the thin-film transistor inside the gate driving circuit 210 changes with temperature. The impedance adjustment circuit 220 can be connected in series or in parallel with the gate driving circuit 210. The impedance adjustment circuit 220 adaptively adjusts its own impedance under different ambient temperatures to match the changes in the equivalent impedance of the gate driving circuit 210. For example, at high temperatures, the electron mobility of the thin-film transistor is high, and the current passing through it is large. The equivalent impedance of the gate driving circuit 210 is the first equivalent impedance, and correspondingly, the impedance of the impedance adjustment circuit 220 is the first impedance. At room temperature, the electron mobility of the thin-film transistor is normal, and the equivalent impedance of the gate driving circuit 210 is the second equivalent impedance, and the impedance of the impedance adjustment circuit 220 is the second impedance. At low temperatures, the electron mobility of the thin-film transistor is low, and the equivalent impedance of the gate driving circuit 210 is the third equivalent impedance, and the impedance of the impedance adjustment circuit 220 is the third impedance. The third equivalent impedance is greater than the second equivalent impedance, and the second equivalent impedance is greater than the first equivalent impedance. According to the connection method between the impedance adjustment circuit 220 and the gate driving circuit 210, the first impedance, the second impedance, and the third impedance can increase or decrease sequentially. At the same time, the total impedance of the first impedance and the first equivalent impedance is equal to the second impedance and the second equivalent impedance, and the total impedance of the third impedance and the third equivalent impedance is equal to the second equivalent impedance. Therefore, the total impedance between the driver chip 230 and the output terminal of the gate driving circuit 210 remains constant at different temperatures. Under the condition that the gate driving signal remains unchanged and the total impedance remains constant, the on-current and off-current of the gate driving circuit 210 remain constant. That is, the gate driving circuit 210 has the same driving current at different ambient temperatures. The current of the horizontal scanning signal received by the display panel 100 is stable, thereby ensuring the consistency of the display effect and avoiding abnormal screen display.

[0050] Meanwhile, the impedance adjustment circuit 220 adaptively adjusts its own impedance in real time when the ambient temperature changes, thereby adaptively adjusting the driving capability of the gate drive circuit 210 during power-on and display, instead of using the compensation circuit to detect and then compensate, thus improving the timeliness of temperature compensation.

[0051] The gate drive circuit 210 can be composed of multiple shift registers cascaded in sequence. The shift registers are composed of multiple thin-film transistors and capacitors, such as shift registers with 4T1C architecture or 7T1C architecture, and the specific structure is not limited.

[0052] The impedance adjustment circuit 220 can adopt a corresponding thermistor NTC, impedance switching circuit, or other structure, and the specific structure is not limited.

[0053] The beneficial effects of the present invention embodiment compared with the prior art are as follows: The driving circuit 200 of the above-mentioned display panel includes a gate driving circuit 210 and an impedance adjustment circuit 220. The impedance adjustment circuit 220 adjusts its own impedance to the target impedance according to the current ambient temperature. The target impedance is different at different temperatures. The target impedance and the equivalent impedance of the gate driving circuit 210 form the total impedance. The total impedance is equal at different ambient temperatures. Correspondingly, the on-current and off-current output by the gate driving circuit 210 remain the same, that is, they have the same driving capability, which ensures the driving effect and display effect of the display panel 100, realizes display consistency, and the impedance adjustment circuit 220 adaptively adjusts its own impedance according to the ambient temperature, which improves the compensation timeliness.

[0054] Example 2

[0055] In an alternative embodiment, such as Figure 1 As shown, the impedance adjustment circuit 220 is connected in series with the input terminal of the gate drive circuit 210. The impedance adjustment circuit 220 is used to receive and transmit the gate drive signal to the gate drive circuit 210.

[0056] Impedance adjustment circuit 220 is used to adjust its own impedance in a positive correlation with ambient temperature.

[0057] In this embodiment, the impedance adjustment circuit 220 is connected in series between the gate driving circuit 210 and the driving chip 230, and transmits the gate driving signal to the gate driving circuit 210. As the ambient temperature increases, the equivalent impedance of the gate driving circuit 210 gradually decreases, while the impedance of the impedance adjustment circuit 220 gradually increases. Therefore, the total impedance of the impedance adjustment circuit 220 and the equivalent impedance of the gate driving circuit 210 is the sum of the two impedances, and the total impedance can remain equal. Under the condition that the gate driving signal remains unchanged and the total impedance remains constant, the on-current and off-current of the gate driving circuit 210 remain constant. That is, the gate driving circuit 210 has the same driving current under different ambient temperatures, and the current of the horizontal scanning signal received by the display panel 100 is stable, thereby ensuring the consistency of the display effect and avoiding abnormal screen display.

[0058] The impedance adjustment circuit 220 can employ structures such as a temperature sensing circuit 222 and an adjustable resistor, for example... Figure 3 As shown, in an optional embodiment, the impedance adjustment circuit 220 includes:

[0059] Impedance output circuit 221 is connected in series with the input terminal of gate drive circuit 210. Impedance output circuit 221 is used to switch the output impedance to different impedances corresponding to the positive change of ambient temperature according to the impedance switching signal.

[0060] Temperature sensing circuit 222 is used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature;

[0061] The comparator circuit 223 is connected to the impedance output circuit 221 and the temperature sensing circuit 222 respectively. The comparator circuit 223 is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

[0062] In this embodiment, the temperature sensing circuit 222 outputs a temperature sensing signal of a corresponding magnitude based on the positive correlation with the ambient temperature. The higher the ambient temperature, the larger the temperature sensing signal. The temperature sensing signal is a voltage signal.

[0063] The comparator circuit 223 has multiple different reference voltages, each representing a different temperature threshold. When the temperature sensing signal reaches a different reference voltage, the comparator circuit 223 outputs impedance switching signals of different magnitudes or numbers. The impedance output circuit 221 switches the output impedance of different magnitudes to the driver chip 230 and the gate driver circuit 210 according to the received impedance switching signals of different magnitudes or numbers.

[0064] For example, at high temperatures, the temperature sensing signal is large and exceeds each reference voltage. The comparator circuit 223 outputs a multi-channel impedance switching signal or a larger impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 switches the output to a larger impedance between the driver chip 230 and the gate driver circuit 210 according to the multi-channel impedance switching signal or the larger impedance switching signal. At this time, the equivalent impedance of the gate driver circuit 210 is small, and the total impedance of the gate driver circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0065] At room temperature, the temperature sensing signal is less than that at high temperature, exceeding a certain reference voltage. The comparator circuit 223 outputs a partial impedance switching signal or a smaller impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 generates a smaller impedance between the driver chip 230 and the gate driver circuit 210 based on the partial impedance switching signal or the smaller impedance switching signal. At this time, the equivalent impedance of the gate driver circuit 210 increases at higher temperatures, and the total impedance of the gate driver circuit 210 and the impedance output circuit 221 is maintained at a preset impedance.

[0066] At low temperatures, the temperature sensing signal is less than that at room temperature and less than each reference voltage. The comparator circuit 223 outputs a smaller impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 generates a smaller impedance between the driver chip 230 and the gate driver circuit 210 based on the smaller impedance switching signal. At this time, the equivalent impedance of the gate driver circuit 210 is larger than that at room temperature, and the total impedance of the gate driver circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0067] As the ambient temperature changes, the equivalent impedance of the gate driving circuit 210 changes negatively with the ambient temperature, while the impedance of the impedance output circuit 221 changes positively with the temperature. The impedance adjustment circuit 220 and the gate driving circuit 210 change positively and negatively respectively, and finally the total impedance of the two is maintained at the preset impedance, so that the current at the output of the gate driving circuit 210 is maintained at the preset current, thereby making the display effect of the display panel 100 consistent and improving the display effect.

[0068] Among them, the impedance output circuit 221 can be a series resistor branch, a switch branch, etc., the comparison circuit 223 can be composed of multiple comparators, and the temperature sensing circuit 222 can be a thermistor NTC, a voltage source, etc.

[0069] In an alternative embodiment, such as Figure 4 As shown, the impedance output circuit 221 includes multiple impedance units connected in series. Each impedance unit includes a switch and a resistor connected in parallel. The switch is connected to the comparator circuit 223.

[0070] Temperature sensing circuit 222 includes a thermistor NTC and a voltage divider resistor R1;

[0071] The first terminal of the thermistor NTC is connected to the positive voltage terminal VCC. The second terminal of the thermistor NTC and the first terminal of the voltage divider resistor R1 are connected to form the output terminal of the temperature sensing circuit 222. The second terminal of the voltage divider resistor R1 is grounded.

[0072] The comparator circuit 223 includes multiple comparators. The inverting input terminal of the comparator is used to input the temperature sensing signal, and the non-inverting input terminal of the comparator is used to input the reference voltage. The output terminals of the multiple comparators are connected to the control terminals of multiple switching switches, and each comparator corresponds to a different reference voltage.

[0073] In this embodiment, taking the comparison circuit 223 including a first comparator U1 and a second comparator U2, and the impedance output circuit 221 including two series-connected impedance units as an example, the first impedance unit includes a first switching switch K1 and a first sub-resistor Rx1 connected in parallel, and the second impedance unit includes a second switching switch K2 and a second sub-resistor Rx2 connected in parallel.

[0074] The reference voltage includes a first reference voltage and a second reference voltage. The first reference voltage is generated by voltage division of the second resistor R2 and the third resistor R3, and the second reference voltage is generated by voltage division of the fourth resistor R4 and the fifth resistor R5. The first reference voltage represents the high temperature threshold, and the second reference voltage represents the low temperature threshold. The first reference voltage is greater than the second reference voltage. The first reference voltage is output to the non-inverting input of the first comparator U1, and the second reference voltage is output to the non-inverting input of the second comparator U2.

[0075] The thermistor NTC is a negative temperature coefficient thermistor. The higher the temperature, the lower the resistance of the thermistor NTC. The temperature sensing signal generated by the voltage division of the thermistor NTC and the voltage divider resistor R1 is larger, that is, the temperature sensing signal changes positively with the ambient temperature.

[0076] When the temperature is high, the temperature sensing signal is greater than the first reference voltage and the second reference voltage. The first comparator U1 and the second comparator U2 output a low level, and the first switch K1 and the second switch K2 are turned off. At this time, the first sub-resistor Rx1 and the second sub-resistor Rx2 are connected in series between the driver chip 230 and the gate drive circuit 210. At this time, the equivalent impedance of the gate drive circuit 210 is small, and the total impedance of the gate drive circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0077] At room temperature, the temperature sensing signal is less than the first reference voltage and greater than the second reference voltage. The first comparator U1 outputs a high level, the second comparator U2 outputs a low level, the first switching switch K1 is turned on, and the second switching switch K2 is turned off. At this time, the first sub-resistor Rx1 is short-circuited, and the second sub-resistor Rx2 is connected in series between the driver chip 230 and the gate driving circuit 210. At this time, the equivalent impedance of the gate driving circuit 210 increases at higher temperatures, and the total impedance of the gate driving circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0078] When the temperature is low, the temperature sensing signal is less than the first reference voltage and the second reference voltage. The first comparator U1 and the second comparator U2 output a high level. At this time, the first switching switch K1 and the second switching switch K2 are turned on and the first sub-resistor Rx1 and the second sub-resistor Rx2 are short-circuited. At this time, the impedance of the impedance output circuit 221 is zero. At this time, the equivalent impedance of the gate drive circuit 210 is larger than that at room temperature. The total impedance of the gate drive circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0079] In order to maintain the total impedance at high temperature, normal temperature and low temperature at the preset impedance, the resistance value of the second sub-resistor Rx2 is equal to the difference between the third equivalent impedance and the second equivalent impedance of the gate drive circuit 210, and the resistance value of the first sub-resistor Rx1 is equal to the difference between the second equivalent impedance and the first equivalent impedance of the gate drive circuit 210.

[0080] Example 3

[0081] In another alternative embodiment, the impedance adjustment circuit 220 is connected in parallel to the input and output terminals of the gate drive circuit 210;

[0082] Impedance adjustment circuit 220 is used to adjust its own impedance in a positive correlation with ambient temperature.

[0083] In this embodiment, the impedance adjustment circuit 220 is connected in parallel between the gate driving circuit 210 and the driving chip 230. It receives the gate driving signal output by the driving chip 230 simultaneously with the gate driving circuit 210. As the ambient temperature increases, the equivalent impedance of the gate driving circuit 210 gradually decreases, while the impedance of the impedance adjustment circuit 220 gradually increases. The sum of the impedances of the parallel gate driving circuit 210 and the impedance adjustment circuit 220 can remain equal. Under the condition that the gate driving signal remains unchanged and the total impedance is constant, the on-current and off-current of the gate driving circuit 210 remain constant. That is, the gate driving circuit 210 has the same driving current under different ambient temperatures. The current of the horizontal scanning signal received by the display panel 100 is stable, thereby ensuring the consistency of the display effect and avoiding abnormal screen display.

[0084] The impedance adjustment circuit 220 can employ structures such as a temperature sensing circuit 222 and an adjustable resistor, for example... Figure 3 As shown, in an optional embodiment, as Figure 5 As shown, the impedance adjustment circuit 220 includes:

[0085] Impedance output circuit 221 is connected in parallel to the input and output terminals of gate drive circuit 210. Impedance output circuit 221 is used to switch the output impedance to different impedances corresponding to the positive change of ambient temperature according to the impedance switching signal.

[0086] Temperature sensing circuit 222 is used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature;

[0087] The comparator circuit 223 is connected to the impedance output circuit 221 and the temperature sensing circuit 222 respectively. The comparator circuit 223 is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

[0088] In this embodiment, the temperature sensing circuit 222 outputs a temperature sensing signal of a corresponding magnitude based on the positive correlation with the ambient temperature. The higher the ambient temperature, the larger the temperature sensing signal. The temperature sensing signal is a voltage signal.

[0089] The comparator circuit 223 has multiple different reference voltages, each representing a different temperature threshold. When the temperature sensing signal reaches a different reference voltage, the comparator circuit 223 outputs impedance switching signals of different magnitudes or numbers. The impedance output circuit 221 switches the output impedance of different magnitudes according to the received impedance switching signals of different magnitudes or numbers, and forms a total impedance with the parallel gate drive circuit 210.

[0090] For example, at high temperatures, the temperature sensing signal is large and exceeds each reference voltage. The comparator circuit 223 outputs a multi-channel impedance switching signal or a larger impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 switches to output a larger impedance according to the multi-channel impedance switching signal or the larger impedance switching signal, and forms a total impedance with the parallel gate drive circuit 210. At this time, the equivalent impedance of the gate drive circuit 210 is small, and the total impedance of the gate drive circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0091] At room temperature, the temperature sensing signal is less than that at high temperature. Exceeding a certain reference voltage, the comparator circuit 223 outputs a partial impedance switching signal or a smaller impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 generates a smaller impedance based on the partial impedance switching signal or the smaller impedance switching signal, and forms a total impedance with the parallel gate drive circuit 210. At this time, the equivalent impedance of the gate drive circuit 210 increases at higher temperatures, and the total impedance of the gate drive circuit 210 and the impedance output circuit 221 is maintained at a preset impedance.

[0092] At low temperatures, the temperature sensing signal is less than that at room temperature and less than each reference voltage. The comparator circuit 223 outputs a smaller impedance switching signal to the impedance output circuit 221. The impedance output circuit 221 generates a smaller impedance based on the smaller impedance switching signal and forms a total impedance with the parallel gate drive circuit 210. At this time, the equivalent impedance of the gate drive circuit 210 is larger than that at room temperature, and the total impedance of the gate drive circuit 210 and the impedance output circuit 221 is maintained at the preset impedance.

[0093] As the ambient temperature changes, the equivalent impedance of the gate driving circuit 210 changes negatively with the ambient temperature, while the impedance of the impedance output circuit 221 changes positively with the temperature. The impedance adjustment circuit 220 and the gate driving circuit 210 change positively and negatively respectively, and finally the total impedance of the two is maintained at the preset impedance, so that the current at the output of the gate driving circuit 210 is maintained at the preset current, thereby making the display effect of the display panel 100 consistent and improving the display effect.

[0094] Among them, the impedance output circuit 221 can be a series resistor branch, a switch branch, etc., the comparison circuit 223 can be composed of multiple comparators, and the temperature sensing circuit 222 can be a thermistor NTC, a voltage source, etc.

[0095] In an alternative embodiment, such as Figure 6 As shown, the impedance output circuit 221 includes multiple impedance units connected in parallel. Each impedance unit includes a series switching switch and a resistor. The switching switch is connected to the comparator circuit 223.

[0096] The comparator circuit 223 includes multiple comparators. The non-inverting input of the comparator is used to input the temperature sensing signal, and the inverting input of the comparator is used to input the reference voltage. The outputs of the multiple comparators are connected to the control terminals of multiple switching switches, and each comparator corresponds to a different reference voltage.

[0097] Temperature sensing circuit 222 includes a thermistor NTC and a voltage divider resistor R1;

[0098] The first terminal of the thermistor NTC is connected to the positive voltage terminal VCC. The second terminal of the thermistor NTC and the first terminal of the voltage divider resistor R1 are connected to form the output terminal of the temperature sensing circuit 222. The second terminal of the voltage divider resistor R1 is grounded.

[0099] In this embodiment, taking the comparison circuit 223 including a first comparator U1 and a second comparator U2, and the impedance output circuit 221 including two impedance units connected in series as an example, the first impedance unit includes a first switching switch K1 and a first sub-resistor Rx1 connected in series, and the second impedance unit includes a second switching switch K2 and a second sub-resistor Rx2 connected in series.

[0100] The reference voltage includes a first reference voltage and a second reference voltage. The first reference voltage is generated by voltage division of the second resistor R2 and the third resistor R3, and the second reference voltage is generated by voltage division of the fourth resistor R4 and the fifth resistor R5. The first reference voltage represents the high temperature threshold, and the second reference voltage represents the low temperature threshold. The first reference voltage is greater than the second reference voltage. The first reference voltage is output to the non-inverting input of the first comparator U1, and the second reference voltage is output to the non-inverting input of the second comparator U2.

[0101] The thermistor NTC is a negative temperature coefficient thermistor. The higher the temperature, the lower the resistance of the thermistor NTC. The temperature sensing signal generated by the voltage division of the thermistor NTC and the voltage divider resistor R1 is larger, that is, the temperature sensing signal changes positively with the ambient temperature.

[0102] When the temperature is high, the temperature sensing signal is greater than the first reference voltage and the second reference voltage. The first comparator U1 and the second comparator U2 output a low level, and the first switch K1 and the second switch K2 are turned off. At this time, the impedance of the impedance output circuit 221 is infinite, the equivalent impedance of the gate drive circuit 210 is small, and the total impedance of the parallel gate drive circuit 210 and the impedance output circuit 221 is maintained at the preset impedance, which is also equal to the impedance of the gate drive circuit 210. Assume that the equivalent impedance of the gate drive circuit 210 at the current high temperature is R01.

[0103] At room temperature, the temperature sensing signal is less than the first reference voltage and greater than the second reference voltage. The first comparator U1 outputs a high level, and the second comparator U2 outputs a low level. The first switch K1 is turned on, and the second switch K2 is turned off. At this time, the first sub-resistor Rx1 is connected in parallel with the gate drive circuit 210, and the second sub-resistor Rx2 is not connected in the parallel circuit. At this time, the equivalent impedance of the gate drive circuit 210 increases at higher temperatures. The total impedance of the gate drive circuit 210 and the impedance output circuit 221 remains at a preset impedance, which is equal to the total impedance of the gate drive circuit 210 in parallel with the first sub-resistor Rx1. Assuming the equivalent impedance of the gate drive circuit 210 at room temperature is R02, the total impedance is equal to:

[0104] ;

[0105] Rs represents the total impedance, and Rx1 represents the impedance of the first sub-resistor Rx1.

[0106] When the temperature is low, the temperature sensing signal is less than the first reference voltage and the second reference voltage. The first comparator U1 and the second comparator U2 output a high level. At this time, the first switch K1 and the second switch K2 are turned on. The first sub-resistor Rx1 and the second sub-resistor Rx2 are simultaneously connected in parallel with the gate drive circuit 210. The resistance values ​​of the first sub-resistor Rx1 and the second sub-resistor Rx2 after parallel connection decrease. At this time, the equivalent impedance of the gate drive circuit 210 is larger than at room temperature. The total impedance of the gate drive circuit 210 and the impedance output circuit 221 remains at a preset impedance, which is equal to the total impedance after parallel connection of the first sub-resistor Rx1, the second sub-resistor Rx2, and the equivalent impedance of the gate drive circuit 210. Assuming the equivalent impedance of the gate drive circuit 210 at the current low temperature is R03, the total impedance is equal to:

[0107] ;

[0108] Rx2 represents the impedance of the second sub-resistor.

[0109] In order to maintain the total impedance at high temperature, room temperature, and low temperature at a preset impedance, the total impedance at the three temperatures must be equal. Therefore, the resistance value of the first sub-resistor Rx1 can be calculated using the above formula as follows:

[0110] ;

[0111] The resistance value of the second sub-resistor Rx2 is equal to:

[0112] .

[0113] Example 4

[0114] A second aspect of the present invention provides a display device, such as... Figure 7 As shown, the display device includes a display panel 100 and a driving circuit 200 for the display panel. The specific structure of the driving circuit 200 for the display panel is as described in the above embodiments. Since this display device adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be described in detail here. The driving circuit 200 for the display panel is connected to the display panel 100.

[0115] In this embodiment, the display panel 100 includes a display area 110 and a non-display area 120. The display area 110 is provided with multiple rows of scan lines, multiple columns of data lines, and pixel units arranged in an array. Each pixel unit is connected to a data line and a scan line. The driving circuit 200 of the display panel is located in the non-display area 120. The data lines and scan lines of the display area 110 extend to the non-display area 120 and are connected to the driving circuit 200 of the display panel. The driving circuit 200 of the display panel provides corresponding data signals and row scan signals. The pixel units display corresponding image information according to the received data signals and row scan signals.

[0116] The driving circuit 200 of the display panel includes a gate driving circuit 210 and an impedance adjustment circuit 220. The driving circuit 200 of the display panel also includes a driving chip 230. The driving chip 230 provides a gate driving signal to the gate driving circuit 210. The driving chip 230 is also connected to multiple columns of data lines and provides data signals. The gate driving circuit 210 is connected to multiple rows of scan lines. The gate driving circuit 210 outputs a row scan signal line by line in each frame according to the received gate driving signal and drives the pixel units to turn on line by line, thereby realizing the line-by-line driving display.

[0117] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention 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 the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A drive circuit of a display panel, characterized by, include: A gate driving circuit is connected to multiple scan lines of the display panel. The gate driving circuit is used to output a row scan signal to the display panel according to the gate driving signal. An impedance adjustment circuit is connected to the gate drive circuit and conducts the gate drive signal. The impedance adjustment circuit is used to adjust its own impedance to a target impedance according to the ambient temperature, so that the total impedance of the target impedance and the equivalent impedance of the gate drive circuit is equal at different ambient temperatures.

2. The driving circuit of a display panel according to claim 1, wherein The impedance adjustment circuit is connected in series at the input terminal of the gate drive circuit, and the impedance adjustment circuit is used to receive and transmit the gate drive signal to the gate drive circuit. The impedance adjustment circuit is used to adjust its own impedance in a positive correlation with the ambient temperature.

3. The driving circuit of a display panel according to claim 2, wherein The impedance adjustment circuit includes: An impedance output circuit is connected in series with the input terminal of the gate drive circuit. The impedance output circuit is used to switch the output impedance to different impedances corresponding to the positive change of ambient temperature according to the impedance switching signal. Temperature sensing circuit, used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature; The comparison circuit is connected to the impedance output circuit and the temperature sensing circuit respectively. The comparison circuit is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

4. The driving circuit of a display panel according to claim 3, wherein The impedance output circuit includes multiple impedance units connected in series. Each impedance unit includes a switch and a resistor connected in parallel. The switch is connected to the comparison circuit.

5. The driving circuit of a display panel according to claim 1, wherein The impedance adjustment circuit is connected in parallel to the input and output terminals of the gate drive circuit. The impedance adjustment circuit is used to adjust its own impedance in a positive correlation with the ambient temperature.

6. The driving circuit of a display panel according to claim 5, wherein The impedance adjustment circuit includes: An impedance output circuit is connected in parallel to the input and output terminals of the gate drive circuit. The impedance output circuit is used to switch the output impedance to different impedances corresponding to the positive correlation change of the ambient temperature according to the impedance switching signal. Temperature sensing circuit, used to generate a temperature sensing signal of corresponding magnitude according to the current ambient temperature; The comparison circuit is connected to the impedance output circuit and the temperature sensing circuit respectively. The comparison circuit is used to compare the temperature sensing signal with different reference voltages and output different impedance switching signals.

7. The driving circuit for the display panel as described in claim 6, characterized in that, The impedance output circuit includes multiple impedance units connected in parallel. Each impedance unit includes a series switching switch and a resistor. The switching switch is connected to the comparison circuit.

8. The driving circuit for the display panel as described in claim 4 or 7, characterized in that, The comparison circuit includes multiple comparators. The inverting input terminal of the comparator is used to input the temperature sensing signal, and the non-inverting input terminal of the comparator is used to input the reference voltage. The output terminals of the multiple comparators are connected to the control terminals of the multiple switching switches one by one, and the reference voltage corresponding to each comparator is different.

9. The driving circuit for the display panel as described in claim 3 or 6, characterized in that, The temperature sensing circuit includes a thermistor and a voltage divider resistor; The first end of the thermistor is connected to the positive voltage terminal, and the second end of the thermistor and the first end of the voltage divider resistor are connected to form the output terminal of the temperature sensing circuit. The second end of the voltage divider resistor is grounded.

10. A display device, characterized in that, It includes a display panel and a driving circuit for the display panel as described in any one of claims 1 to 9, wherein the driving circuit for the display panel is connected to the display panel.

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