Shutdown control circuit of display panel and display device

Abstract

The application relates to a display panel shutdown control circuit and a display device. The shutdown control circuit comprises a first detection circuit and a second detection circuit. The first detection circuit is connected with a source electrode driving circuit, and the second detection circuit is connected with a scanning driving circuit. The first detection circuit outputs a first signal when a first voltage reaches a first threshold voltage. The first voltage decays to zero potential when the display panel is shut down. The first signal is used to reduce the voltage output by the source electrode driving circuit to a first target voltage. The second detection circuit outputs a second signal when a second voltage reaches a second threshold voltage. The second voltage decays to zero potential when the display panel executes a shutdown operation. The second signal is used to increase the voltage output by the scanning driving circuit to a second target voltage. The second target voltage is used to turn on a thin film transistor of the display panel. The application can effectively solve the shutdown residual image problem.

Description

Technical Field

[0001] This utility model relates to the field of display technology, and in particular to a power-off control circuit and display device for a display panel. Background Technology

[0002] Currently, to address the issue of screen-off ghosting in thin film transistor liquid crystal displays (TFT LCDs), the timing controller embedded in the display driver chip (TED) is designed with an integrated circuit (IC) analog power supply low voltage detection (LVD) function.

[0003] The LVD function is triggered when the analog voltage for electrode (AVEE) reaches the power-down trigger threshold. The LVD function includes pulling the source output low to ground (GND) and pulling the gate driver in array (GIA) signal high to the gate high voltage (VGH) to open the residual charge in the TFT neutral plane and resolve the power-off ghosting problem.

[0004] However, when the pattern of the displayed image is heavily loaded, or when the impedance of the wire on array (WOA) increases under high temperature testing during reliability assurance (RA), the AVEE voltage may fluctuate, potentially causing the AVEE voltage to reach the power-down trigger threshold, thereby triggering the LVD function erroneously and resulting in abnormal image display. Utility Model Content

[0005] This invention provides a power-off control circuit and display device for a display panel to solve the power-off ghosting problem of thin film transistor liquid crystal display (TFT LCD).

[0006] In a first aspect, this utility model provides a power-off control circuit for a display panel, comprising: a first detection circuit and a second detection circuit, wherein the first detection circuit is connected to a source driving circuit of the display panel, and the second detection circuit is connected to a scan driving circuit of the display panel; the first detection circuit is used to detect a first voltage and output a first signal when the first voltage reaches a first threshold voltage, wherein when the display panel performs a power-off operation, the first voltage decays to zero potential, and the first signal is used to reduce the voltage output by the source driving circuit to a first target voltage, wherein the value of the first target voltage is less than or equal to the value of a common voltage; the second detection circuit is used to detect a second voltage and output a second signal when the second voltage reaches a second threshold voltage, wherein when the display panel performs a power-off operation, the second voltage decays to zero potential, and the second signal is used to increase the voltage output by the scan driving circuit to a second target voltage, wherein the second target voltage is used to turn on the thin-film transistors of the display panel.

[0007] In conjunction with the first aspect, in one possible implementation, the power-off control circuit further includes: a level conversion circuit, the input terminal of which is connected to the output terminal of the second detection circuit, and the output terminal of which is connected to the scan drive circuit; the level conversion circuit is used to receive the second signal and output the second target voltage to the scan drive circuit based on the second signal.

[0008] In conjunction with the first aspect, in one possible implementation, the power-off control circuit further includes: a third detection circuit and a control unit; the input terminal of the third detection circuit is connected to the output terminal of the level conversion circuit, the output terminal of the third detection circuit is connected to the first input terminal of the control unit, the second input terminal of the control unit is connected to the output terminal of the first detection circuit, the first output terminal of the control unit is connected to the scan drive circuit, and the second output terminal of the control unit is connected to the source drive circuit; the third detection circuit is used to detect the voltage signal output by the level conversion circuit, and when the voltage of the voltage signal is greater than or equal to the second target voltage, output a third signal to the control unit; the control unit is used to, upon receiving the first signal and the third signal, control the voltage output by the source drive circuit to decrease to the first target voltage, and control the voltage output by the scan drive circuit to increase to the second target voltage.

[0009] In conjunction with the first aspect, in one possible implementation, the control unit includes a half-adder circuit.

[0010] In conjunction with the first aspect, in one possible implementation, the first voltage includes: the negative drive circuit voltage of the display panel; and the first signal indicates that the low-voltage detection function of the display panel is triggered.

[0011] In conjunction with the first aspect, in one possible implementation, the second voltage includes: the power supply voltage of the display panel; and the second signal indicates that the full-on function of the display panel is triggered.

[0012] In conjunction with the first aspect, in one possible implementation, the first detection circuit includes: a first voltage comparator; the first voltage comparator is configured to input the first voltage through a first input terminal, input the first threshold voltage through a second input terminal, and output the first signal to the source drive circuit through an output terminal when the first voltage reaches the first threshold voltage.

[0013] In conjunction with the first aspect, in one possible implementation, the second detection circuit includes: a second voltage comparator; the second voltage comparator is configured to input the second voltage through a first input terminal, input the second threshold voltage through a second input terminal, and output the second signal to the scan drive circuit through an output terminal when the second voltage reaches the second threshold voltage.

[0014] In conjunction with the first aspect, in one possible implementation, the third detection circuit includes: a third voltage comparator; the third voltage comparator is configured to input the voltage signal through a first input terminal, input the second target voltage through a second input terminal, and output a third signal to the control unit through an output terminal when the voltage signal is greater than or equal to the second target voltage.

[0015] In conjunction with the first aspect, in one possible implementation, the first target voltage includes: ground voltage, or common voltage.

[0016] In conjunction with the first aspect, in one possible implementation, the second target voltage includes: a gate high voltage, or the backlight module voltage of the display panel.

[0017] Secondly, the present invention provides a display device, which includes a power-off control circuit as described in the first aspect or any possible implementation thereof.

[0018] This invention provides a power-off control circuit and display device for a display panel. The technical solution provided by this invention determines whether the display panel has performed a power-off operation by detecting multiple voltages (such as a first voltage and a second voltage) related to the power-off operation. After confirming the power-off operation, a residual charge release operation is triggered in the display panel to solve the problem of power-off ghosting. The residual charge release operation in the display panel includes: reducing the voltage output by the source drive circuit to a first target voltage, and turning on the thin-film transistors of the display panel. By detecting multiple voltages, this invention improves the accuracy of power-off operation judgment, thereby reducing the probability of erroneous triggering of the power-off ghosting elimination operation due to incorrect power-off operation judgment, resulting in abnormal screen display, improving user experience, and reducing the maintenance cost of the display panel. Attached Figure Description

[0019] Figures 1 to 4 A schematic structural diagram of the power-off control circuit for the display panel provided by this utility model; Figure 5 This is a schematic diagram illustrating a triggering condition provided by the present invention. Detailed Implementation

[0020] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] A pixel unit in a thin-film transistor liquid crystal display (TFT-LCD) includes a TFT and a capacitor unit, which includes a pixel capacitor and a storage capacitor. The gate of the TFT receives the scan voltage, which turns the TFT on or off. When the TFT is on, the data voltage is transmitted through the source of the TFT to the pixel electrode to control the deflection of the liquid crystal molecules to display the image. At this time, the storage capacitor stores charge. When the TFT is off, the charge stored in the storage capacitor maintains the voltage across the liquid crystal molecules, preventing image flickering after the TFT is turned off. However, if the charge in the storage capacitor cannot be released quickly enough when the LCD is turned off, or if the release rate of the charge in the storage capacitor is less than the LCD's shutdown speed, the liquid crystal molecules will continue to be deflected due to residual charge, leaving a ghost image on the screen.

[0022] To address the issue of image retention when an LCD is powered off, the timing controller embedded in the display driver chip incorporates an integrated circuit (IC) low-voltage detection (LVD) function to simulate a low-voltage power supply. This allows for the rapid release of charge from the storage capacitor when the LCD is powered off. The LVD function is triggered when the analog voltage for the electrode (AVEE) reaches the power-down trigger threshold. The LVD function involves: pulling the source output low to ground (GND) to make the source potential of the TFT GND; and controlling the gate driver in array (GIA) signal high to the gate high voltage (VGH) to turn on the TFT, allowing the charge stored in the storage capacitor to flow to GND through the conducting TFT. As can be seen, the LVD function provides a rapid release channel for the charge in the storage capacitor, thus avoiding residual images after power-off. It should be noted that the AVEE voltage gradually decreases when the LCD is powered off. Therefore, the AVEE power-down trigger threshold can be set as the condition for triggering the LVD function. For example, when the LCD is displaying a normal image, the AVEE voltage is -4.4 volts (V). When the LCD is powered off, the AVEE voltage will gradually decay to GND, reaching -4V during the decay process, thus triggering the LVD function. -4V can be understood as the power-down trigger threshold.

[0023] However, as a sensitive analog drive voltage, the stability of the AVEE voltage is directly affected by load current fluctuations. For example, when the display pattern load is large, or when the impedance of the wire-on-array (WOA) increases under high-temperature reliability assurance (RA) tests, the AVEE voltage may fluctuate, potentially reaching the power-down trigger threshold. This could lead to a false triggering of the LVD function, causing the power-off ghosting elimination operation (such as adjusting the source output and GIA output) to be performed without the display panel being powered off, resulting in abnormal display.

[0024] It should be noted that the display pattern in a TFT-LCD can be various thin-film patterns, such as gate line patterns and pixel electrode patterns. Different patterns will produce different load effects on the circuit. For example, some complex image patterns or high-resolution display content will have higher current requirements on the driving circuit, and the corresponding pattern will have a larger load, which may cause fluctuations in the AVEE voltage. WOA is a technology that fabricates wires on the array substrate to connect the driving chip and other components and transmit signals when the liquid crystal display panel is displayed. Under the high temperature test of RA, the impedance of WOA may increase, which will affect the current and voltage distribution in the circuit and cause AVEE voltage fluctuations.

[0025] In view of this, the present invention provides a power-off control circuit and display device for a display panel. The technical solution provided by the present invention combines multiple detection methods to determine whether the display panel has performed a power-off operation. Only after confirming the power-off operation is performed is the release of residual charge in the display panel triggered, thereby solving the problem of power-off ghosting. The technical solution provided by the present invention can improve the accuracy of power-off operation judgment, thereby reducing the probability of erroneous triggering of power-off ghosting elimination operations due to incorrect power-off operation judgment, leading to abnormal screen display, improving user experience, and reducing the maintenance cost of the display panel.

[0026] The following is combined with Figures 1 to 5 The technical solution provided by this utility model will be described below.

[0027] Figure 1 A schematic structural diagram of a power-off control circuit for a display panel provided by this utility model. Figure 1 The power-off control circuit 100 shown includes: a first detection circuit 110 and a second detection circuit 120.

[0028] like Figure 1 As shown, the first detection circuit 110 is connected to the source drive circuit of the display panel, and the second detection circuit 120 is connected to the scan drive circuit of the display panel.

[0029] The first detection circuit 110 is used to detect a first voltage and output a first signal when the first voltage reaches a first threshold voltage. When the display panel performs a power-off operation, the first voltage decays to zero potential. Zero potential can also be called a zero potential reference point, such as GND. It should be understood that when the display panel performs a power-off operation, the first voltage first decays to the first threshold voltage, and then decays to zero potential. Therefore, by determining whether the first voltage reaches the first threshold voltage, it can be determined whether the first voltage is in a decaying state, and thus whether the display panel has performed a power-off operation. The first threshold voltage can be set according to actual needs, and this invention does not limit it.

[0030] The first signal output by the first detection circuit 110 is used to reduce the voltage output by the source drive circuit to a first target voltage. The value of the first target voltage can be less than or equal to the value of the common voltage (Vcom). Optionally, the first target voltage can be: ground voltage or common voltage.

[0031] In one possible implementation, the first voltage can be the AVEE voltage. The first voltage reaching a first threshold voltage can be understood as the AVEE voltage reaching the first threshold voltage during its return to GND when the display panel is powered off. In this implementation, the first signal can be used to indicate the triggering of the LVD function of the display panel. Compared with the LVD function in the prior art, the LVD function in this invention is only used to reduce the source output to a first target voltage.

[0032] Optionally, the first signal and the first target voltage can be set in advance in the source drive circuit. After receiving the first signal, the source drive circuit outputs the first target voltage in response to the first signal.

[0033] The second detection circuit 120 is used to detect the second voltage and output a second signal when the second voltage reaches a second threshold voltage. When the display panel performs a power-off operation, the second voltage decays to zero potential. Similar to the first voltage, when the display panel performs a power-off operation, the second voltage first decays to the second threshold voltage, and then decays to zero potential. By determining whether the second voltage reaches the second threshold voltage, it can be determined whether the second voltage is in a decaying state, and thus whether the display panel has performed a power-off operation. The second threshold voltage can be set according to actual needs, and this utility model does not limit it.

[0034] The second signal output by the second detection circuit 120 is used to raise the voltage output by the scan drive circuit to a second target voltage, which is used to turn on the TFT of the display panel. It should be understood that the value of the second target voltage is greater than or equal to the gate high voltage (VGH). Optionally, the second target voltage can be VGH, or the backlight module voltage of the display panel.

[0035] In one possible implementation, the second voltage can be the power supply voltage (Vin) of the display panel. The second voltage reaching a second threshold voltage can be understood as Vin reaching the second threshold voltage during its return to GND when the display panel is powered off. In this implementation, the second signal can be used to indicate the triggering of the display panel's output all-on (XON) function. It should be understood that the triggering condition for the XON function is that Vin reaches the second threshold voltage. The XON function includes raising the output of the scan drive circuit to a second target voltage to turn on the TFT.

[0036] Optionally, the second signal and the second target voltage can be preset in the scan drive circuit. After receiving the second signal, the scan drive circuit outputs the second target voltage in response to the second signal, thereby turning on the TFT.

[0037] In this invention, both the first voltage and the second voltage are related to the power-off operation of the display panel. Therefore, by detecting the first and second voltages, it can be determined whether the display panel has performed a power-off operation. After confirming that a power-off operation has been performed, the residual charge in the display panel is released to solve the problem of power-off ghosting. The release process includes: pulling down the output voltage of the source drive circuit to a first target potential, and raising the voltage output of the scan drive circuit to a second target potential to turn on the TFT, thereby achieving rapid release of residual charge in the display panel. The release process can also be referred to as the power-off ghosting elimination operation.

[0038] This invention improves the accuracy of determining whether a power-off operation has been performed by detecting dual voltages. This reduces the probability of erroneous triggering of the power-off ghosting elimination operation due to incorrect power-off operation judgment, thereby improving the user experience and reducing the maintenance cost of the display panel.

[0039] In one possible implementation, the number of detection circuits or detection voltages can be greater than two, without any specific limitation.

[0040] In one possible implementation, the power-off control circuit 100 may further include a level conversion circuit 130, which may be located between the second detection circuit 120 and the scan drive circuit, such as... Figure 2 As shown. See also Figure 2 The input terminal of the level conversion circuit 130 is connected to the output terminal of the second detection circuit 120, and the output terminal of the level conversion circuit 130 is connected to the scanning drive circuit.

[0041] The level conversion circuit 130 is used to receive a second signal from the second detection circuit 120, and based on the second signal, output a second target voltage to the scan drive circuit to increase the voltage output by the scan drive circuit, thereby turning on the TFT. It should be understood that... Figure 2 The second signal output by the second detection circuit 120 is high level.

[0042] In this implementation, a level-shifting circuit is introduced to isolate the detection circuit and the driving circuit, thereby effectively suppressing noise and improving the anti-interference capability of the shutdown control circuit. Furthermore, in this implementation, the trigger condition for the XON function is that Vin reaches the second threshold voltage. The XON function includes: raising the output of the scan driving circuit to the second target voltage through the level-shifting circuit to turn on the TFT.

[0043] In one possible implementation, the shutdown control circuit 100 may further include a third detection circuit 140 and a control unit 150, such as... Figure 3 As shown.

[0044] See Figure 3 The input terminal of the third detection circuit 140 is connected to the output terminal of the level conversion circuit 130. The output terminal of the third detection circuit 140 is connected to the first input terminal of the control unit 150. The second input terminal of the control unit 150 is connected to the output terminal of the first detection circuit 110. The first output terminal of the control unit 150 is connected to the scan drive circuit. The second output terminal of the control unit 150 is connected to the source drive circuit.

[0045] The third detection circuit 140 is used to detect the voltage signal output by the level conversion circuit 130, and to output a third signal to the control unit 150 when the voltage signal is greater than or equal to the second target voltage. Optionally, the voltage signal output by the level conversion circuit 130 may include the gate low voltage (VGL) and VGH.

[0046] The control unit 150 is used to control the voltage output of the source drive circuit to decrease to a first target voltage and control the voltage output of the scan drive circuit to increase to a second target voltage when receiving the first signal and the third signal, so as to eliminate the shutdown afterimage.

[0047] In this implementation, a third detection circuit is introduced to detect the voltage signal output by the level conversion circuit. When the voltage signal is greater than or equal to the second target voltage, a third signal is output to the control unit to indicate that the XON function is triggered when the display panel performs a power-off operation.

[0048] In this implementation, the control unit performs the power-off ghosting elimination operation when the first voltage reaches the first threshold voltage and the voltage signal output by the level conversion circuit reaches the second target voltage simultaneously, or when the control unit performs the LVD function and the XON function simultaneously. This improves the accuracy of the power-off operation judgment, thereby reducing the probability of screen display abnormalities caused by the erroneous triggering of the power-off ghosting elimination operation due to incorrect power-off operation judgment, improving the user experience, and reducing the maintenance cost of the display panel.

[0049] Figure 4 A schematic structural diagram of another power-off control circuit for a display panel provided by this utility model. Figure 4 The shutdown control circuit shown is an example of the first detection circuit, the second detection circuit, the third detection circuit, and the control unit.

[0050] like Figure 4As shown, the first detection circuit 110 may include a first voltage comparator C1. The first voltage comparator C1 is used to input a first voltage through a first input terminal, input a first threshold voltage through a second input terminal, and output a first signal through its output terminal when the first voltage reaches the first threshold voltage. It should be noted that when the shutdown control circuit 100 includes a control unit 150, the first voltage comparator C1 can output a first signal to the control unit 150 through its output terminal when the first voltage reaches the first threshold voltage. When the shutdown control circuit 100 does not include a control unit 150, the first voltage comparator C1 can output a first signal to the source drive circuit through its output terminal when the first voltage reaches the first threshold voltage. The specific configuration can be adjusted according to actual needs and is not specifically limited here.

[0051] Taking the AVEE voltage as an example, the first voltage comparator C1 is used to input the AVEE voltage through the first input terminal, input the first threshold voltage through the second input terminal, and output a first signal through the output terminal when the AVEE voltage reaches the first threshold voltage. The first signal indicates that the LVD function is triggered. Figure 4 The first threshold voltage is provided by resistor R and a current source. It should be understood that AVEE is a negative voltage, and the decay process of AVEE can be understood as AVEE gradually increasing to 0 volts (V), as... Figure 5 As shown. The first threshold voltage is as follows. Figure 5 The LVD detection voltage in the middle.

[0052] This invention can determine whether the LVD function is triggered by the output of the first voltage comparator C1. Figure 4 As shown, if the AVEE voltage is greater than the first threshold voltage, the first voltage comparator C1 outputs a high level, indicating that the LVD function is triggered; if the AVEE voltage is less than the first threshold voltage, the first voltage comparator C1 outputs a low level, indicating that the LVD function is not triggered.

[0053] like Figure 4As shown, the second detection circuit 120 may include a second voltage comparator C2. The second voltage comparator C2 is used to input a second voltage through a first input terminal, input a second threshold voltage (Vr2 in the figure) through a second input terminal, and output a second signal through its output terminal when the second voltage reaches the second threshold voltage. It should be noted that when the power-off control circuit 100 includes a level conversion circuit 130, a third detection circuit 140, and a control unit 150, the second voltage comparator C2 can output a second signal to the level conversion circuit 130 through its output terminal when the second voltage reaches the second threshold voltage. When the power-off control circuit 100 does not include the level conversion circuit 130, the third detection circuit 140, and the control unit 150, the second voltage comparator C2 can output a second signal to the scan drive circuit through its output terminal when the second voltage reaches the second threshold voltage. The specific configuration can be determined according to actual needs and is not specifically limited here.

[0054] Taking Vin as an example, the second voltage comparator C2 is used to input the Vin voltage through the first input terminal, output a second threshold voltage through the second input terminal, and output a second signal through the output terminal when Vin reaches the second threshold voltage. The second signal indicates that the XON function is triggered. It should be understood that Vin is a positive voltage, and the decay process of Vin can be understood as Vin gradually decreasing to 0V. Figure 5 As shown. The second threshold voltage is as follows. Figure 5 2.0 V in the middle.

[0055] This invention can determine whether the XON function is triggered by the output of the second voltage comparator C2. For example... Figure 4 As shown, if Vin is greater than the second threshold voltage, the second voltage comparator C2 outputs a high level, indicating that the XON function is not triggered; if Vin is less than the second threshold voltage, the second voltage comparator C2 outputs a low level, indicating that the XON function is triggered.

[0056] like Figure 4 As shown, the third detection circuit 140 may include a third voltage comparator C3. The third voltage comparator C3 is used to input the voltage signal output by the level conversion circuit 130 through the first input terminal, input the second target voltage through the second input terminal, and output a third signal to the control unit through the output terminal when the voltage signal is greater than or equal to the second target voltage.

[0057] This invention can determine whether the XON function is triggered by judging whether the voltage signal output by the level conversion circuit is greater than the second target voltage based on the output result of the third voltage comparator C3. Figure 4As shown, if the voltage signal output by the level conversion circuit (V3 in the figure) is greater than the second target voltage (Vr3 in the figure), then the third voltage comparator C3 outputs a high level, indicating that the XON function is triggered; if the voltage signal output by the level conversion circuit is less than the second target voltage, then the third voltage comparator C3 outputs a low level, indicating that the XON function is not triggered. The second target voltage is as follows: Figure 5 VGH in the text. It should be understood that... Figure 4 The first voltage comparator C1, the second voltage comparator C2, and the third voltage comparator C3 in the figure are merely examples and are not intended to limit the technical solution of this utility model.

[0058] like Figure 4 As shown, the control unit 150 may include a half-adder circuit.

[0059] The two input terminals of the half-adder circuit are used for inputs A and B, respectively, and the two output terminals are used for outputs S and C, respectively. The table below shows the truth table and functional state description of the half-adder circuit.

[0060]

[0061] It should be noted that A can be understood as the first signal output by the first voltage comparator C1; A = 1 indicates that the LVD function is triggered, and A = 0 indicates that the LVD function is not triggered. B can be understood as the signal output by the third voltage comparator C3; B = 1 indicates that the XON function is triggered and the voltage signal output by the level conversion circuit rises to VGH; B = 0 indicates that the XON function is not triggered and / or the voltage signal output by the level conversion circuit is less than VGH. S can be understood as the signal output by the half-adder circuit to the source drive circuit, and C can be understood as the signal output by the half-adder circuit to the scan drive circuit.

[0062] like Figure 4 As shown, when the control unit 150 outputs a signal "1" to the source drive circuit and a signal "0" to the scan drive circuit, a residual charge release operation is performed in the display panel, such as the power-off discharge operation in the table. That is, the source drive circuit can output a first target voltage in response to the signal "1", and the gate drive circuit can output a second target voltage in response to the signal "0" to turn on the TFT, thereby releasing the residual charge in the display panel.

[0063] In this invention, by introducing digital circuits such as voltage comparators and half-adder circuits, the robustness of the shutdown control circuit can be improved, thereby effectively solving the problem of screen ghosting on the display panel during shutdown.

[0064] This utility model also provides a display device, which includes the power-off control circuit in the foregoing embodiments.

[0065] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0066] In the description of this utility model, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0067] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, the technical features involved in the different embodiments of this utility model described above can be combined with each other as long as they do not conflict with each other.

[0068] It should be emphasized that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model shall still fall within the scope of the technical solution of the present utility model.

Claims

1. A display panel power-off control circuit, characterized by comprising: include: A first detection circuit and a second detection circuit, wherein the first detection circuit is connected to the source driving circuit of the display panel and the second detection circuit is connected to the scan driving circuit of the display panel. The first detection circuit is used to detect a first voltage and output a first signal when the first voltage reaches a first threshold voltage. When the display panel performs a power-off operation, the first voltage will decay to zero potential. The first signal is used to reduce the voltage output by the source drive circuit to a first target voltage. The value of the first target voltage is less than or equal to the value of the common voltage. The second detection circuit is used to detect the second voltage and output a second signal when the second voltage reaches a second threshold voltage. When the display panel performs a power-off operation, the second voltage will decay to zero potential. The second signal is used to raise the voltage output by the scan drive circuit to a second target voltage. The second target voltage is used to turn on the thin-film transistors of the display panel.

2. The power-off control circuit according to claim 1, characterized by Also includes: A level conversion circuit, wherein the input terminal of the level conversion circuit is connected to the output terminal of the second detection circuit, and the output terminal of the level conversion circuit is connected to the scan drive circuit; The level conversion circuit is used to receive the second signal and output the second target voltage to the scan drive circuit based on the second signal.

3. The shutdown control circuit according to claim 2, characterized in that, Also includes: A third detection circuit and a control unit, wherein the input terminal of the third detection circuit is connected to the output terminal of the level conversion circuit, the output terminal of the third detection circuit is connected to the first input terminal of the control unit, the second input terminal of the control unit is connected to the output terminal of the first detection circuit, the first output terminal of the control unit is connected to the scan driving circuit, and the second output terminal of the control unit is connected to the source driving circuit; The third detection circuit is used to detect the voltage signal output by the level conversion circuit, and to output a third signal to the control unit when the voltage of the voltage signal is greater than or equal to the second target voltage. The control unit is configured to, upon receiving the first signal and the third signal, control the voltage output by the source drive circuit to decrease to the first target voltage, and control the voltage output by the scan drive circuit to increase to the second target voltage.

4. The power-off control circuit of claim 3, wherein The control unit includes a half-adder circuit.

5. The shutdown control circuit of any one of claims 1 to 4, wherein, The first voltage includes: the voltage of the negative drive circuit of the display panel; The first signal indicates that the low-voltage detection function of the display panel is triggered.

6. The shutdown control circuit according to any one of claims 1 to 4, characterized in that, The second voltage includes: the power supply voltage of the display panel; The second signal indicates that the full-on function of the display panel is triggered.

7. The shutdown control circuit according to claim 1, characterized in that, The first detection circuit includes: a first voltage comparator; The first voltage comparator is configured to receive the first voltage through a first input terminal, receive the first threshold voltage through a second input terminal, and output the first signal to the source drive circuit through an output terminal when the first voltage reaches the first threshold voltage.

8. The power-off control circuit of claim 1, wherein, The second detection circuit includes: a second voltage comparator; The second voltage comparator is used to input the second voltage through the first input terminal, input the second threshold voltage through the second input terminal, and output the second signal to the scan drive circuit through the output terminal when the second voltage reaches the second threshold voltage.

9. The power-off control circuit of claim 4, wherein, The third detection circuit includes: a third voltage comparator; The third voltage comparator is used to input the voltage signal through the first input terminal, input the second target voltage through the second input terminal, and output a third signal to the control unit through the output terminal when the voltage signal is greater than or equal to the second target voltage.

10. A display device, characterized in that, Includes a shutdown control circuit as described in any one of claims 1 to 9.

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