Gating circuit and display panel

Abstract

The application discloses a gate-on circuit and a display panel. In the gate-on circuit: a power supply line is connected with a power supply end, and the power supply end provides a power supply voltage for the power supply line; one end of a voltage reduction switch module is connected with the power supply line, and the other end is used for connecting a voltage reduction circuit; one end of a voltage increase switch module is connected with the power supply line, and the other end is used for connecting a voltage increase circuit; one end of a contrast output module is connected with the power supply line, and the other end is used for connecting an output circuit; the contrast output module is used for receiving a lower limit voltage and an upper limit voltage, when the power supply voltage is between the lower limit voltage and the upper limit voltage, the contrast output module is turned on, and the voltage reduction switch module and the voltage increase switch module are both turned off; when the power supply voltage is less than the lower limit voltage, the voltage increase switch module is turned on, and the voltage reduction switch module and the contrast output module are both turned off; when the power supply voltage is greater than the upper limit voltage, the voltage reduction switch module is turned on, and the voltage increase switch module and the contrast output module are both turned off. The technical scheme of the application can effectively reduce the influence of the external environment temperature on the resistance of metal wiring.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of display, and particularly relates to a gate-on circuit and a display panel. BACKGROUND

[0002] The switching voltage required by the display screen is generally converted by the internal circuit of the control chip and then input to the panel. However, since the data line connected to the panel is usually a metal trace, the resistivity of the metal trace will change when the resistance of the metal trace is affected by the external temperature. When the resistance of the metal trace is greatly affected by the external temperature, the switching voltage reaching the panel will be directly affected, thereby causing abnormal display of the display screen, and even causing the display screen to fail to start normally. SUMMARY

[0003] The application aims to provide a gate-on circuit which can effectively reduce the influence of the external environmental temperature on the resistance of the metal trace, ensure the accuracy of the switching voltage reaching the panel, and reduce abnormal display of the display screen and the situation that the display screen fails to start normally.

[0004] Other characteristics and advantages of the application will become apparent from the following detailed description, or will be learned by practice of the application.

[0005] According to an aspect of an embodiment of the application, the application provides a gate-on circuit, which comprises:

[0006] a power supply line connected to a power supply end, wherein the power supply end provides a power supply voltage to the power supply line;

[0007] a step-down switch module, one end of the step-down switch module being connected to the power supply line, and the other end of the step-down switch module being used for connecting a step-down circuit;

[0008] a step-up switch module, one end of the step-up switch module being connected to the power supply line, and the other end of the step-up switch module being used for connecting a step-up circuit;

[0009] a comparison output module, one end of the comparison output module being connected to the power supply line, and the other end of the comparison output module being used for connecting an output circuit;

[0010] The comparison output module is used for receiving a lower limit voltage and an upper limit voltage, the upper limit voltage being greater than the lower limit voltage, the power supply voltage being between the lower limit voltage and the upper limit voltage, the comparison output module being turned on, and the step-down switch module and the step-up switch module being both disconnected;

[0011] The power supply voltage is less than the lower limit voltage, the step-up switch module is turned on, and the step-down switch module and the comparison output module are both disconnected;

[0012] When the supply voltage is greater than the upper limit voltage, the step-down switch module is turned on, and the step-up switch module and the comparison output module are both turned off.

[0013] In one aspect, the step-down switch module includes a first voltage-stabilizing diode and a first transistor, the emitter of the first transistor is connected to the power supply line, the emitter of the first transistor is connected to the step-down circuit, the anode of the first voltage-stabilizing diode is connected to the base of the first transistor, the cathode of the first voltage-stabilizing diode is connected to the first ground wire, one end of the first ground wire is connected to the power supply line, and the other end of the first ground wire is grounded.

[0014] In one aspect, the step-down switch module further includes a first current-limiting resistor and a first voltage-dividing resistor, and the first current-limiting resistor and the first voltage-dividing resistor are arranged on the first ground line;

[0015] The cathode of the first voltage-limiting diode is connected to the first node of the first ground line, one end of the first current-limiting resistor is connected to the first node, and the other end of the first current-limiting resistor is grounded;

[0016] One end of the first voltage-dividing resistor is connected to the first node, and the other end of the first voltage-dividing resistor is connected to the power supply line.

[0017] In one aspect, the lower limit voltage is a threshold voltage of the first Zener diode.

[0018] In one aspect, the boost switch module includes a first gating submodule and a second gating submodule;

[0019] The threshold voltage of the first gating submodule is the upper limit voltage, and the second gating submodule has a turn-on voltage, which is less than the lower limit voltage;

[0020] One end of the first gating submodule is connected to the power supply line, and the other end of the first gating submodule is grounded;

[0021] One end of the second gating submodule is connected to the power supply line, the other end of the second gating submodule is connected to the boost circuit, and the second gating submodule is connected to the first gating submodule;

[0022] When the supply voltage is greater than the turn-on voltage and less than the lower limit voltage, the second gating submodule is turned on, and the step-down switch module and the comparison output module are both turned off.

[0023] In one aspect, the first gating submodule includes: a second voltage stabilizing diode and a second triode, and the second gating submodule includes a third voltage stabilizing diode and a response switch;

[0024] an anode of the second voltage stabilizing diode is connected to the second triode collector, a cathode of the second voltage stabilizing diode is connected to the power supply line, and a base of the second triode is connected to a line between the cathode of the second voltage stabilizing diode and the power supply line;

[0025] an input of the response switch is connected to the power supply line, an output of the response switch is connected to the voltage boosting circuit, an anode of the third voltage stabilizing diode is connected to the second triode collector, a cathode of the third voltage stabilizing diode is connected to the power supply line, and a control terminal of the response switch is connected to the anode of the third voltage stabilizing diode.

[0026] In one aspect, the first gating sub-module includes a second current-limiting resistor, a third current-limiting resistor, and a second voltage-dividing resistor, and the second gating sub-module includes a fourth current-limiting resistor.

[0027] one end of the second current-limiting resistor is connected to the cathode of the second voltage stabilizing diode, and the other end of the second current-limiting resistor is connected to the power supply line;

[0028] one end of the second voltage-dividing resistor is connected to the base of the second triode, and the other end of the second voltage-dividing resistor is connected to a line between the second current-limiting resistor and the second voltage stabilizing diode;

[0029] one end of the third current-limiting resistor is connected to the second triode collector, and the other end of the third current-limiting resistor is grounded;

[0030] one end of the fourth current-limiting resistor is connected to the anode of the third voltage stabilizing diode and the control terminal of the response switch, and the other end of the fourth current-limiting resistor is grounded.

[0031] In one aspect, the upper limit voltage is a threshold voltage of the second voltage stabilizing diode.

[0032] In one aspect, the contrast output module includes a first operational amplifier and a second operational amplifier, the first operational amplifier has a first same-direction input terminal and a first reverse-direction input terminal, and the second operational amplifier has a second same-direction input terminal and a second reverse-direction input terminal;

[0033] the first same-direction input terminal of the first operational amplifier is configured to receive the lower limit voltage, the second reverse-direction input terminal of the second operational amplifier is configured to receive the upper limit voltage, and the first reverse-direction input terminal of the first operational amplifier and the second same-direction input terminal of the second operational amplifier are both connected to the power supply line;

[0034] The contrast output module further comprises a third triode, the output end of the first operational amplifier and the output end of the second operational amplifier are connected to the base of the third triode, the collector of the third triode is connected to the power supply line, and the emitter of the third triode is grounded, and the output circuit is connected to the collector of the third triode.

[0035] In addition, in order to solve the above problems, the application further provides a display panel, which comprises a control chip and a gate-on-off circuit as described above, the control chip is connected to the power supply end of the gate-on-off circuit, and the control chip provides the power supply voltage to the power supply line.

[0036] In the application, when the power supply voltage provided by the power supply line is between the upper limit voltage and the lower limit voltage, it indicates that the power supply voltage is less affected by the ambient temperature, at this time, the contrast output module is started to conduct, and the power supply voltage is directly output through the output circuit of the contrast output module. When the power supply voltage is less than the lower limit voltage, it indicates that the ambient temperature affects the voltage of the power supply line, resulting in a decrease in the power supply voltage, at this time, the boost switch module is started to conduct, and the power supply voltage is output to the boost circuit through the boost switch module, and the boost circuit can increase the size of the power supply voltage to reduce the case that the power supply voltage is reduced by temperature. When the power supply voltage is greater than the upper limit voltage, it also indicates that the ambient temperature affects the voltage of the power supply line, resulting in an excessively high power supply voltage, at this time, the buck switch module is started to conduct, and the power supply voltage is output to the buck circuit through the buck switch module, and the buck circuit can reduce the size of the power supply voltage. Therefore, by starting one of the buck switch module, the boost switch module and the contrast output module to conduct, the influence of the external ambient temperature on the resistance of the metal trace can be reduced, the accuracy of the in-plane switching voltage can be ensured, and the abnormal display of the picture and the failure of the display screen to normally start can be reduced.

[0037] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0038] The drawings incorporated into the specification and constituting a part of the specification show embodiments consistent with the application and, together with the specification, serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained from these drawings without creative labor for those skilled in the art.

[0039] Figure 1 The circuit schematic diagram of an embodiment of the gate-on-off circuit of the application is schematically shown.

[0040] Figure 2The circuit schematic diagram of the step-down switch module in the gating circuit of the application is shown schematically.

[0041] Figure 3 The circuit signal direction schematic diagram of the step-up switch module conduction in the gating circuit of the application is shown schematically.

[0042] Figure 4 The circuit signal direction schematic diagram of the contrast output module in the gating circuit of the application is shown schematically.

[0043] Figure 5 The circuit signal direction schematic diagram of the step-down switch module conduction in the gating circuit of the application is shown schematically.

[0044] Figure 6 The schematic diagram of the control chip connecting the gating circuit in an embodiment of the display panel of the application is shown schematically.

[0045] The reference signs are explained as follows:

[0046] VIN, power supply line; 110, step-down switch module; 120, contrast output module; 130, step-up switch module; 140, control chip; D1, first voltage stabilizing diode; D2, second voltage stabilizing diode; D3, third voltage stabilizing diode; Q1, first triode; Q2, second triode; Q3, third triode; T, response switch; R1, first current limiting resistor; R2, second current limiting resistor; R3, third current limiting resistor; R4, fourth current limiting resistor; r1, first voltage dividing resistor; r2, second voltage dividing resistor; Vout1, step-down circuit; Vout2, step-up circuit; Vout3, output circuit; V1, lower limit voltage; V2, upper limit voltage; V3, conduction voltage; U1, first operational amplifier; U2, second operational amplifier; 131, first gating sub-module; 132, second gating sub-module. DETAILED DESCRIPTION

[0047] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations may, however, be implemented in many different forms and should not be construed as limited to the examples set forth herein; rather, these implementations are provided so that this disclosure will be thorough and complete, and will fully convey the scope of example implementations to those skilled in the art.

[0048] Embodiment one

[0049] Reference is made to Figure 1 As shown in the drawings, a gating circuit includes a power supply line VIN, a step-down switch module 110, a step-up switch module 130 and a contrast output module 120.

[0050] The power supply line VIN is connected to the power supply end, and the power supply end provides a power supply voltage to the power supply line VIN. The power supply line VIN is generally a metal line or a line whose resistivity is more likely to change when the temperature changes.

[0051] One end of the buck switch module 110 is connected to the power supply line VIN, and the other end of the buck switch module 110 is used to connect to the buck circuit Vout1; the buck voltage is used to reduce the size of the power supply voltage. When the buck switch module 110 is started and turned on, the power supply voltage will flow to the buck circuit Vout1 through the buck switch module 110.

[0052] One end of the boost switch module 130 is connected to the power supply line VIN, and the other end of the boost switch module 130 is used to connect to the boost circuit Vout2; when the boost switch module 130 is started and turned on, the supply voltage will flow to the boost circuit Vout2 through the boost switch module 130, and the boost circuit Vout2 will increase the size of the supply voltage.

[0053] One end of the contrast output module 120 is connected to the power supply line VIN, and the other end of the contrast output module 120 is used to connect to the output circuit Vout3; when the contrast output module 120 is started and turned on, the power supply voltage is output normally and transmitted to the in-plane components of the display panel through the output circuit Vout3.

[0054] Specifically, the comparison output module 120 is configured to receive a lower limit voltage V1 and an upper limit voltage V2, where the upper limit voltage V2 is greater than the lower limit voltage V1. Generally, if the supply voltage exceeds the upper limit voltage V2, it indicates that the supply voltage is too high and requires voltage reduction. If the supply voltage is lower than the lower limit voltage V1, it indicates that the supply voltage is too low and requires voltage increase. If the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, it indicates that the supply voltage is within normal limits and the temperature has limited impact on the power supply line VIN. In this case, the supply voltage can be directly output.

[0055] For example, when the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the comparison output module 120 is turned on, and the buck switch module 110 and the boost switch module 130 are both turned off. It is understandable that when the supply voltage is within a normal fluctuation range, only the comparison output module 120 is turned on, while the buck switch module 110 and the boost switch module 130 are turned off, thereby reducing the impact on the normal output supply voltage of the power supply line VIN.

[0056] When the supply voltage is less than the lower limit voltage V1, the boost switch module 130 is turned on, and the buck switch module 110 and the comparison output module 120 are both disconnected. It can also be understood that when the supply voltage is less than the lower limit voltage V1, it means that the supply voltage is too low. At this time, only the boost switch module 130 is turned on, while the buck switch module 110 and the comparison output module 120 are both disconnected, thereby reducing the impact on the boost process.

[0057] When the supply voltage is greater than the upper voltage limit V2, the step-down switch module 110 is turned on, while the boost switch module 130 and the comparison output module 120 are both turned off. When the supply voltage is greater than the upper voltage limit V2, indicating that the supply voltage is too high, the step-down switch module 110 is turned on to step down the voltage. The boost switch module 130 and the comparison output module 120 are both turned off to minimize the impact on the step-down process.

[0058] In this embodiment, an upper voltage limit V2 and a lower voltage limit V1 are provided. When the supply voltage provided by the power supply line VIN is between the upper voltage limit V2 and the lower voltage limit V1, the supply voltage is less affected by the ambient temperature. In this case, the comparison output module 120 is activated and the supply voltage is directly output through the output circuit Vout3 of the comparison output module 120. When the supply voltage is less than the lower voltage limit V1, it indicates that the ambient temperature has affected the voltage level of the power supply line VIN, causing the supply voltage to decrease. In this case, the boost switch module 130 is activated and the supply voltage is output to the boost circuit Vout2 through the boost switch module 130. The boost circuit Vout2 can increase the supply voltage level, reducing the temperature drop in the supply voltage. When the supply voltage is greater than the upper voltage limit V2, it also indicates that the ambient temperature has affected the voltage level of the power supply line VIN, causing the supply voltage to be too high. In this case, the buck switch module 110 is activated and the supply voltage is output to the buck circuit Vout1 through the buck switch module 110. The buck circuit Vout1 can reduce the supply voltage level. It can be seen that by starting and turning on one of the buck switch module 110, the boost switch module 130 and the comparison output module 120, the influence of the external ambient temperature on the resistance of the metal traces can be reduced, the accuracy of the switching voltage within the surface can be ensured, and the situation where the screen display is abnormal and the display screen cannot be turned on normally can be reduced.

[0059] In one embodiment of the present application, for the buck switch module 110, the buck switch module 110 includes a first voltage-stabilizing diode D1 and a first transistor Q1, the emitter of the first transistor Q1 is connected to the power supply line VIN, the collector of the first transistor Q1 is connected to the buck circuit Vout1, the anode of the first voltage-stabilizing diode D1 is connected to the base of the first transistor Q1, the cathode of the first voltage-stabilizing diode D1 is connected to the first ground line, one end of the first ground line is connected to the power supply line VIN, and the other end of the first ground line is grounded.

[0060] When the supply voltage is lower than the lower limit voltage V1, the first voltage regulator diode D1 is not conducting, the base of the first transistor Q1 does not receive the voltage signal, and the first transistor Q1 is turned off. The buck switch module 110 is in the off state, and the buck circuit Vout1 cannot intervene in operation.

[0061] It should be noted that in the embodiment, the first triode Q1 can be a PNP type triode, and the voltage difference between the base and the emitter of the first triode Q1 is greater than the initial conduction voltage V3 of the emission junction, so that the first triode Q1 can be turned on.

[0062] When the supply voltage is greater than the lower limit voltage V1 and less than the upper limit voltage V2, the first voltage stabilizing diode D1 is turned on, but the voltage difference between the base and the emitter of the first triode Q1 is less than the conduction condition of the first triode Q1, and the first triode Q1 is still in the off state, so that the voltage reduction circuit Vout1 cannot intervene in the work.

[0063] When the supply voltage is greater than the upper limit voltage V2, the first voltage stabilizing diode D1 is turned on, and the voltage difference between the base and the emitter of the first triode Q1 meets the conduction condition of the first triode Q1, and the first triode Q1 is turned on. The supply line VIN is connected to the voltage reduction circuit Vout1 through the voltage reduction switch module 110, and the supply voltage is reduced through the voltage reduction circuit Vout1, and then the reduced supply voltage is provided to the in-plane components of the display panel.

[0064] In an embodiment of the present application, the voltage reduction switch module 110 further includes a first current limiting resistor R1 and a first voltage dividing resistor r1, and the first current limiting resistor R1 and the first voltage dividing resistor r1 are arranged on the first ground line; the negative electrode of the first voltage stabilizing diode D1 is connected to a first node of the first ground line, one end of the first current limiting resistor R1 is connected to the first node, and the other end of the first current limiting resistor R1 is grounded; one end of the first voltage dividing resistor r1 is connected to the first node, and the other end of the first voltage dividing resistor r1 is connected to the supply line VIN.

[0065] The first current limiting resistor R1 can reduce the current size on the first ground line, and can also protect the first voltage stabilizing diode D1. The first voltage dividing resistor can share the voltage size applied to the negative electrode of the first voltage stabilizing diode D1, and ensure that the voltage applied to the first voltage stabilizing diode D1 meets the design requirements.

[0066] In an embodiment of the present application, the lower limit voltage V1 is the threshold voltage of the first voltage stabilizing diode D1. When the supply voltage is lower than the lower limit voltage V1, i.e. the supply voltage is lower than the threshold voltage of the first voltage stabilizing diode D1, the first voltage stabilizing diode D1 is in the off state, and when the supply voltage is greater than the threshold voltage of the first voltage stabilizing diode D1, the first voltage stabilizing diode D1 is turned on. It should be noted that when the first voltage stabilizing diode D1 is turned on, it is a reverse breakdown conduction, i.e. the negative electrode voltage of the first voltage stabilizing diode D1 is greater than the threshold voltage, and the positive electrode voltage signal is stabilized and then loaded to the base of the first triode Q1.

[0067] Reference Figure 2As shown in the embodiment of the present application, the voltage boosting switch module 130 comprises a first gating sub-module 131 and a second gating sub-module 132; the threshold voltage of the first gating sub-module 131 is the upper limit voltage V2, and the second gating sub-module 132 has a conduction voltage V3, which is less than the lower limit voltage V1; one end of the first gating sub-module 131 is connected to the power supply line VIN, and the other end of the first gating sub-module 131 is grounded; one end of the second gating sub-module 132 is connected to the power supply line VIN, and the other end of the second gating sub-module 132 is connected to the voltage boosting circuit Vout2, and the second gating sub-module 132 is connected to the first gating sub-module 131.

[0068] When the power supply voltage is greater than the conduction voltage V3 and less than the lower limit voltage V1, it means that the power supply voltage is too low, the second gating sub-module 132 is turned on, and the voltage reducing switch module 110 and the contrast output module 120 are both disconnected. By turning on the second gating sub-module 132, the power supply line VIN can be connected to the voltage boosting circuit Vout2, and the size of the power supply voltage is increased by the voltage boosting circuit Vout2.

[0069] When the power supply voltage is less than the lower limit voltage V1, it is also less than the upper limit voltage V2, that is, the power supply voltage is less than the threshold voltage of the first gating sub-module 131, the first gating sub-module 131 is disconnected, and does not intervene in the work.

[0070] In the embodiment of the present application, the first gating sub-module 131 comprises a second zener diode D2 and a second triode Q2, and the second gating sub-module 132 comprises a third zener diode D3 and a response switch T.

[0071] The emitter of the second triode Q2 is connected to the power supply line VIN, the collector of the second triode Q2 is grounded, the anode of the second zener diode D2 is connected to the collector of the second triode Q2, the cathode of the second zener diode D2 is connected to the power supply line VIN, and the base of the second triode Q2 is connected to the line between the cathode of the second zener diode D2 and the power supply line VIN; the input end of the response switch T is connected to the power supply line VIN, the output end of the response switch T is connected to the voltage boosting circuit Vout2, the anode of the third zener diode D3 is connected to the collector of the second triode Q2, the cathode of the third zener diode D3 is connected to the power supply line VIN, and the control end of the response switch T is connected to the anode of the third zener diode D3. The conduction voltage V3 of the second gating sub-module 132 is the threshold voltage of the third zener diode D3.

[0072] The specific working process of the voltage boosting switch module 130 is as follows:

[0073] When the supply voltage is less than the lower limit voltage V1 and greater than the turn-on voltage V3, the second voltage stabilizing diode D2 is turned off and does not conduct. In this way, the potential difference between the emitter and the base of the second triode Q2 does not satisfy the turn-on condition of the second triode Q2, and the second triode Q2 is turned off. The third voltage stabilizing diode D3 is turned on, and the supply voltage on the supply line VIN forms a clamping voltage through the third voltage stabilizing diode D3, which is defined as V, and the supply voltage on the supply line VIN is V0, and the voltage after the voltage division through the third voltage stabilizing diode D3 is V0-V. At this time, the voltage at the control end of the response switch T is less than the voltage on the supply line VIN and satisfies the turn-on condition of the response switch T, and the response switch T is turned on to connect the supply line VIN to the boost circuit Vout2. The response switch T can be a P-type MOS tube.

[0074] When the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the second voltage stabilizing diode D2 is still turned off and does not conduct. The potential difference between the emitter and the base of the second triode Q2 satisfies the turn-on condition of the second triode Q2, and the second triode Q2 is turned on. The potential at the control end of the response switch T is equal to the potential at the input end, and the response switch T is also turned off to cut off the communication between the boost switch module 130 and the boost circuit Vout2.

[0075] When the supply voltage is greater than the upper limit voltage V2, the second voltage stabilizing diode D2 is turned on, and the potential difference between the emitter and the base of the second triode Q2 satisfies the turn-on condition of the second triode Q2, and the second triode Q2 is turned on. As a result, the potential at the control end of the response switch T is equal to the potential at the input end, and the response switch T is still turned off to cut off the communication between the boost switch module 130 and the boost circuit Vout2.

[0076] In an embodiment of the present application, the first gating sub-module 131 includes a second current limiting resistor R2, a third current limiting resistor R3, and a second voltage dividing resistor r2, and the second gating sub-module 132 includes a fourth current limiting resistor R4. One end of the second current limiting resistor R2 is connected to the negative electrode of the second voltage stabilizing diode D2, and the other end of the second current limiting resistor R2 is connected to the supply line VIN. One end of the second voltage dividing resistor r2 is connected to the base of the second triode Q2, and the other end of the second voltage dividing resistor r2 is connected to the circuit between the second current limiting resistor R2 and the second voltage stabilizing diode D2. One end of the third current limiting resistor R3 is connected to the collector of the second triode Q2, and the other end of the third current limiting resistor R3 is grounded. One end of the fourth current limiting resistor R4 is connected to the positive electrode of the third voltage stabilizing diode D3 and the control end of the response switch T, and the other end of the fourth current limiting resistor R4 is grounded.

[0077] The second current-limiting resistor R2, the third current-limiting resistor R3 and the fourth current-limiting resistor R4 are used to reduce the current on the line, so as to avoid the current being too large to break the voltage stabilizing diode or the triode. The second current-limiting resistor R2 is used to protect the second voltage stabilizing diode D2, and the third current-limiting resistor R3 is used to protect the second triode Q2. The fourth current-limiting resistor R4 is used to protect the third voltage stabilizing diode D3. The second voltage dividing resistor r2 is used to protect the second triode Q2, and also used to share the voltage on the base of the second triode Q2, so as to ensure that the voltage on the base of the second triode Q2 meets the design requirements.

[0078] In an embodiment of the present application, the upper limit voltage V2 is the threshold voltage of the second voltage stabilizing diode D2. The second voltage stabilizing diode D2 is turned on only when the supply voltage is greater than the upper limit voltage V2, i.e. greater than the threshold voltage of the second voltage stabilizing diode D2. The second voltage stabilizing diode D2 is turned off when the supply voltage is less than the upper limit voltage V2, i.e. less than the threshold voltage of the second voltage stabilizing diode D2.

[0079] In an embodiment of the present application, the comparison output module 120 includes a first operational amplifier U1 and a second operational amplifier U2, the first operational amplifier U1 has a first same direction input end and a first reverse input end, and the second operational amplifier U2 has a second same direction input end and a second reverse input end; the first same direction input end of the first operational amplifier U1 is used to receive the lower limit voltage V1, the second reverse input end of the second operational amplifier U2 is used to receive the upper limit voltage V2, and the first reverse input end of the first operational amplifier U1 and the second same direction input end of the second operational amplifier U2 are both connected to the supply line VIN; the lower limit voltage V1 can be transmitted to the first operational amplifier U1 through a data line, and the upper limit voltage V2 can also be transmitted to the second operational amplifier U2 through another data line. The first operational amplifier U1 can receive the lower limit voltage V1 and the supply voltage, and compare the data sizes of the two. The second operational amplifier U2 can receive the upper limit voltage V2 and the supply voltage, and compare the data sizes of the two.

[0080] The comparison output module 120 further includes a third triode Q3, the output end of the first operational amplifier U1 and the output end of the second operational amplifier U2 are both connected to the base of the third triode Q3, the collector of the third triode Q3 is connected to the supply line VIN, the emitter of the third triode Q3 is grounded, and the output circuit Vout3 is connected to the collector of the third triode Q3.

[0081] For the working process of the comparison output module 120:

[0082] When the supply voltage is less than the lower limit voltage V1, the supply voltage of the power supply line VIN enters the first inverting input terminal of the first operational amplifier U1, and the supply voltage also enters the second non-inverting input terminal of the second operational amplifier U2. The output terminal of the second operational amplifier U2 is silent, the output terminal of the first operational amplifier U1 outputs a high level, the third transistor Q3 is turned on, and the third transistor Q3 is connected to ground. The voltage of the output circuit Vout3 is pulled down to the ground voltage, and the output circuit Vout3 has no output.

[0083] When the supply voltage is greater than the upper limit voltage V2, the output end of the first operational amplifier U1 has no output, the output end of the second operational amplifier U2 outputs a high level, the third transistor Q3 is turned on and grounded, the voltage of the output circuit Vout3 is pulled down to the ground voltage, and the output circuit Vout3 has no output.

[0084] When the supply voltage is between the lower limit voltage V1 and the upper limit voltage V2, the supply voltage at the first inverting input of the first operational amplifier U1 is greater than the lower limit voltage V1 of the first non-inverting input, resulting in no output from the first operational amplifier U1. The upper limit voltage V2 at the second inverting input of the second operational amplifier U2 is greater than the supply voltage at the second non-inverting input, resulting in no output from the second operational amplifier U2. Therefore, the base voltage of the third transistor Q3 is zero, and the third transistor Q3 is disconnected. The supply voltage is then directly transmitted to the output circuit Vout3.

[0085] To further illustrate the working process of each stage, the present application further describes it according to the different power supply voltages. The first zener diode D1, the second zener diode D2, and the third zener diode D3 all have reverse conduction characteristics. The first transistor Q1 and the second transistor Q2 can be PNP type, and the third transistor Q3 can be NPN type.

[0086] When the supply voltage of the power supply line VIN is lower than the conduction voltage V3, that is, lower than the threshold voltage of the third voltage stabilizing diode D3, it indicates that the supply voltage is too low and does not meet the requirements. The buck switch module 110, the boost switch module 130 and the comparison output module 120 are all in the off state.

[0087] See Figure 3 As shown, when the supply voltage is greater than or equal to the conduction voltage V3 and less than the lower limit voltage V1, the third Zener diode D3 conducts in reverse. In response to the control terminal of the response switch T receiving the control voltage passing through the third Zener diode D3, the response switch T turns on, and the power supply line VIN connects to the boost circuit Vout2. Simultaneously, the first Zener diode D1 and the second Zener diode D2 are both off, and the first Zener diode Q1 and the second Zener diode Q2 are off. The third transistor Q3 is on, and the output circuit Vout3 is grounded. Therefore, only the boost circuit Vout2 is functioning.

[0088] Referring to Figure 4 As shown in the figure, when the supply voltage is greater than or equal to the lower limit voltage V1, the supply voltage and less than or equal to the upper limit voltage V2, the first operational amplifier U1 and the second operational amplifier U2 have no output, the third transistor Q3 is off, the comparison output module 120 works, and the supply voltage is directly transmitted through the output circuit Vout3. At the same time, the first zener diode D1 is reverse conducting, but the first transistor Q1 does not meet the conducting condition, the first transistor Q1 is off, and the voltage reduction switch module 110 is in the off state, disconnecting the connection with the voltage reduction circuit Vout1. The supply voltage is lower than the threshold voltage of the second zener diode D2, and the second zener diode D2 is off. The voltage at the base end of the second transistor Q2 is less than the voltage at the emitter, and the voltage difference makes the second transistor Q2 meet the conducting condition, but after the second transistor Q2 is turned on, the control end and the input end of the response switch T are at the same potential, the control end of the response switch T does not meet the opening condition, and the response switch T is off, so the voltage increase switch module 130 is also in the off state.

[0089] Referring to Figure 5 As shown in the figure, when the supply voltage is greater than the upper limit voltage V2, the first zener diode D1 is conducting, and the voltage difference between the base and the emitter of the first transistor Q1 meets the conducting condition of the first transistor Q1, the emitter voltage of the first transistor Q1 is greater than the base voltage, the voltage difference meets the conducting condition, the first transistor Q1 is conducting, and the supply line VIN is connected to the voltage reduction circuit Vout1 through the voltage reduction switch module 110 to reduce the supply voltage. In the voltage increase switch module 130, the second zener diode D2 is conducting, the potential difference between the collector and the base of the second transistor Q2 meets the conducting condition of the second transistor Q2, and the second transistor Q2 is also conducting. Thus, the potential of the control end and the input end of the response switch T is equal, the response switch T is still in the off state, that is, the voltage increase switch module 130 is disconnected from the voltage increase circuit Vout2. At the same time, in the comparison output module 120, the third transistor Q3 is conducting, the voltage of the output circuit Vout3 is pulled down to the ground voltage, the output circuit Vout3 has no output, or it can be understood that the output circuit Vout3 provides zero voltage.

[0090] Since the threshold voltage of different zener diodes varies, in order to ensure that the first zener diode D1, the second zener diode D2 and the third zener diode D3 can be conducting, the voltage difference between the emitter and the base needs to be greater than the difference between the upper limit voltage and the lower limit voltage.

[0091] Embodiment Two

[0092] Referring to Figure 6As shown, the present application also provides a display panel, the display panel comprising the control chip 140 and the gate-on circuit as above, the control chip 140 being connected to the power supply end of the gate-on circuit, and the control chip 140 providing the power supply voltage to the power supply line VIN. The gate-on circuit generally supplies power to the thin film transistor switch of the display panel, ensures that the thin film transistor switch can be accurately turned on or off, reduces the accidental start condition of the thin film transistor switch, thereby reducing the abnormality of the display picture and reducing the picture flicker.

[0093] The above display panel can also be applied to mobile vehicles, such as vehicles, ships or aircraft. Especially for vehicles and ships, the peripheral temperature environment of the loaded display panel will change, and sometimes it may also face extreme temperature environment. Such changes in ambient temperature will affect the resistivity of the data line in the display panel, and through the gate-on circuit in the present embodiment, one of the step-down switch module 110, the step-up switch module 130 and the contrast output module 120 can be selected according to the temperature, and the switch voltage can be output according to the ambient temperature, reducing the influence of temperature changes on the resistivity of the data line. In addition, the above display panel can also be applied to some scenes where the ambient temperature changes greatly.

[0094] Other specific embodiments and advantages of the display panel are described with reference to the above gate-on circuit scheme, and will not be repeated here.

[0095] Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. It is intended that the application cover any and all variations of the application that come within the scope of the general concept of the application and that the claims be interpreted not to be limited to the specific examples described above. It is intended that the application cover any and all variations of the application that come within the scope of the general concept of the application and that the claims be interpreted not to be limited to the specific examples described above.

[0096] It should be understood that the application is not limited to the precise construction that has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made by those skilled in the art without departing from the scope of the application. The scope of the application should only be limited by the appended claims.

Claims

1. A gating circuit, characterized in that: The gating circuit comprises: a power supply line, the power supply line being connected to a power supply terminal, the power supply terminal providing a power supply voltage to the power supply line; a step-down switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to the step-down circuit; the step-down switch module includes a first voltage-regulating diode, a first transistor, a first current-limiting resistor, and a first voltage-dividing resistor; the emitter of the first transistor is connected to the power supply line, the collector of the first transistor is connected to the step-down circuit, the anode of the first voltage-regulating diode is connected to the base of the first transistor, the cathode of the first voltage-regulating diode is connected to a first grounding wire, one end of the first grounding wire is connected to the power supply line, and the other end of the first grounding wire is grounded; the first current-limiting resistor and the first voltage-dividing resistor are arranged on the first grounding wire; the cathode of the first voltage-regulating diode is connected to a first node of the first grounding wire, one end of the first current-limiting resistor is connected to the first node, and the other end of the first current-limiting resistor is grounded; one end of the first voltage-dividing resistor is connected to the first node, and the other end of the first voltage-dividing resistor is connected to the power supply line; a boost switch module, one end of which is connected to the power supply line, and the other end of which is used to connect to a boost circuit; a comparison output module, one end of which is connected to the power supply line, and the other end of which is used to connect to an output circuit; The comparison output module is used to receive a lower limit voltage and an upper limit voltage, wherein the lower limit voltage is the threshold voltage of the first voltage stabilizing diode, and the upper limit voltage is greater than the lower limit voltage. When the supply voltage is between the lower limit voltage and the upper limit voltage, the comparison output module is turned on, and the buck switch module and the boost switch module are both turned off; The supply voltage is lower than the lower limit voltage, the boost switch module is turned on, and the buck switch module and the comparison output module are both turned off; When the supply voltage is greater than the upper limit voltage, the step-down switch module is turned on, and the step-up switch module and the comparison output module are both turned off.

2. The gating circuit according to claim 1, wherein: The boost switch module includes a first gating submodule and a second gating submodule; The threshold voltage of the first gating submodule is the upper limit voltage, and the second gating submodule has a turn-on voltage, which is less than the lower limit voltage; One end of the first gating submodule is connected to the power supply line, and the other end of the first gating submodule is grounded; One end of the second gating submodule is connected to the power supply line, the other end of the second gating submodule is connected to the boost circuit, and the second gating submodule is connected to the first gating submodule; When the supply voltage is greater than the turn-on voltage and less than the lower limit voltage, the second gating submodule is turned on, and the step-down switch module and the comparison output module are both turned off.

3. The gating circuit according to claim 2, wherein: The first gating submodule includes: a second voltage stabilizing diode and a second triode, and the second gating submodule includes a third voltage stabilizing diode and a response switch; The emitter of the second transistor is connected to the power supply line, the collector of the second transistor is grounded, the anode of the second Zener diode is connected to the collector of the second transistor, the cathode of the second Zener diode is connected to the power supply line, and the base of the second transistor is connected to the line between the cathode of the second Zener diode and the power supply line; The input end of the response switch is connected to the power supply line, the output end of the response switch is connected to the boost circuit, the anode of the third voltage regulator diode is connected to the collector of the second transistor, the cathode of the third voltage regulator diode is connected to the power supply line, and the control end of the response switch is connected to the anode of the third voltage regulator diode.

4. The gating circuit according to claim 3, wherein: The first gating submodule includes a second current limiting resistor, a third current limiting resistor and a second voltage dividing resistor, and the second gating submodule includes a fourth current limiting resistor; One end of the second current limiting resistor is connected to the cathode of the second voltage stabilizing diode, and the other end of the second current limiting resistor is connected to the power supply line; One end of the second voltage-dividing resistor is connected to the base of the second transistor, and the other end of the second voltage-dividing resistor is connected to the line between the second current-limiting resistor and the second voltage-stabilizing diode; One end of the third current limiting resistor is connected to the collector of the second transistor, and the other end of the third current limiting resistor is grounded; One end of the fourth current limiting resistor is connected to the anode of the third voltage stabilizing diode and the control end of the response switch, and the other end of the fourth current limiting resistor is grounded.

5. The gating circuit according to claim 3, wherein: The upper limit voltage is a threshold voltage of the second zener diode.

6. The gating circuit according to any one of claims 1 to 5, characterized in that: The comparison output module includes a first operational amplifier and a second operational amplifier, the first operational amplifier having a first non-inverting input terminal and a first inverting input terminal, and the second operational amplifier having a second non-inverting input terminal and a second inverting input terminal; The first non-inverting input terminal of the first operational amplifier is used to receive the lower limit voltage, the second inverting input terminal of the second operational amplifier is used to receive the upper limit voltage, and the first inverting input terminal of the first operational amplifier and the second non-inverting input terminal of the second operational amplifier are both connected to the power supply line; The comparison output module also includes a third transistor, the output end of the first operational amplifier and the output end of the second operational amplifier are both connected to the base of the third transistor, the collector of the third transistor is connected to the power supply line, the emitter of the third transistor is grounded, and the output circuit is connected to the collector of the third transistor.

7. A display panel, characterized in that: The display panel includes a control chip and the gating circuit according to any one of claims 1 to 6, the control chip is connected to a power supply terminal of the gating circuit, and the control chip provides the power supply voltage to the power supply line.

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