Driving circuit of display panel and display device

Abstract

The application discloses a display panel driving circuit and a display device. The driving circuit comprises a plurality of control circuits and a plurality of output ports. The control circuit comprises a digital-to-analog conversion circuit, a selection circuit and a voltage follower circuit. The digital-to-analog conversion circuit is used for converting a digital data signal into an analog data signal and outputting the analog data signal to the selection circuit. The selection circuit is used for outputting the analog data signal to the voltage follower circuit. The selection circuit outputs the analog data signal to a first input end or a second input end according to the polarity of the digital data signal. When the analog data signal is output to the first input end, the output port outputs a positive polarity analog data signal. When the analog data signal is output to the second input end, the output port outputs a negative polarity analog data signal. The application uses the positive phase or the inverse phase processing of the voltage follower circuit to output analog data signals with different polarities. The circuit design is simple, occupies less space and has lower cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a driving circuit of display panel and display device. BACKGROUND

[0002] Liquid crystal display panel (referred to as LCD display panel) has the advantages of high resolution, accurate color restoration, simple structure, high stability, etc. The traditional LCD display panel controls the passing amount of polarized light by the deflection of liquid crystal molecules to realize different gray scale display. However, in the LCD display panel, the liquid crystal molecules are driven to rotate by applying voltage on both sides of the liquid crystal layer. If a single direction electric field is applied on the liquid crystal molecules for a long time, the liquid crystal molecules will be polarized. After the polarization of the liquid crystal molecules, the response characteristics of the liquid crystal will change, such as slow response speed, uneven display, etc. Moreover, the continuous single direction electric field may cause irreversible damage to the liquid crystal molecules, shortening the service life of the liquid crystal display. Therefore, polarity inversion is needed to avoid the polarization of the liquid crystal molecules.

[0003] However, in the driving circuit of the display panel, two groups of digital-to-analog conversion circuits are usually needed to output data signals of positive polarity and negative polarity respectively, but the two groups of digital-to-analog conversion circuits occupy a large design resource, resulting in an increase in cost. SUMMARY

[0004] The purpose of the present application is to provide a driving circuit of display panel and display device, which outputs analog data signals with different polarities by using positive or negative processing of voltage follower circuit, and has the advantages of simpler circuit design, smaller occupied space and lower cost.

[0005] The present application discloses a driving circuit of display panel, the display panel comprising a plurality of data lines, the driving circuit comprising a plurality of control circuits and a plurality of output ports, each control circuit being connected to an output port, and each output port being connected to a data line; the control circuit comprising a digital-to-analog conversion circuit, a selection circuit and a voltage follower circuit, the digital-to-analog conversion circuit being used to convert digital data signals into analog data signals and output the analog data signals to the selection circuit; the selection circuit being used to output the analog data signals to the voltage follower circuit; the voltage follower circuit being provided with a first input end and a second input end, and the output end of the voltage follower circuit being connected to an output port; wherein the selection circuit outputs the analog data signals to the first input end or the second input end according to the polarity of the digital data signals; when the analog data signals are output to the first input end, the output port outputs analog data signals of positive polarity, and when the analog data signals are output to the second input end, the output port outputs analog data signals of negative polarity.

[0006] Optionally, only one of the digital-to-analog conversion circuits is arranged in each of the control circuits, and the digital-to-analog conversion circuit is used to convert a digital data signal of positive polarity or negative polarity into an analog data signal of positive polarity and output the analog data signal to the selection circuit.

[0007] Optionally, the selection circuit comprises a first active switch and a second active switch, a control end of the first active switch is connected to a first polarity adjustment signal, and a control end of the second active switch is connected to a second polarity adjustment signal; an input end of the first active switch and an input end of the second active switch are respectively connected to an output end of the digital-to-analog conversion circuit; the voltage follower circuit comprises an operational amplifier, the operational amplifier comprises a non-inverting input end and an inverting input end, the first input end is the non-inverting input end, and the second input end is the inverting input end; an output end of the first active switch is connected to the non-inverting input end, an output end of the second active switch is connected to the inverting input end, and an output end of the operational amplifier is connected to the output port; when the digital data signal is of positive polarity, the first polarity adjustment signal is a working level, and the first active switch is in a conductive state; when the digital data signal is of negative polarity, the second polarity adjustment signal is a working level, and the second active switch is in a conductive state.

[0008] Optionally, the selection circuit further comprises a third active switch, a control end of the third active switch is connected to the second polarity adjustment signal, an input end of the third active switch is connected to a ground signal end, and an output end of the third active switch is connected to the non-inverting input end, so as to connect the non-inverting input end to the ground signal end when the second polarity adjustment signal is a working level; the voltage follower circuit further comprises a first resistor and a second resistor, one end of the first resistor is connected to the inverting input end, and the other end of the first resistor is connected to the output end of the operational amplifier; one end of the second resistor is connected to the output end of the digital-to-analog conversion circuit, and the other end of the second resistor is connected to the inverting input end.

[0009] Optionally, a resistance value of the first resistor is greater than or equal to a resistance value of the second resistor.

[0010] Optionally, the driving circuit further comprises a resistance feedback module, the resistance feedback module receives an analog data signal output by the digital-to-analog conversion circuit and an analog data signal output by the voltage follower circuit, and controls a resistance value of the inverting input end according to a potential size of the analog data signal output by the digital-to-analog conversion circuit and the analog data signal output by the voltage follower circuit.

[0011] Optionally, when the potential of the analog data signal output by the digital-to-analog conversion circuit is greater than the potential of the analog data signal output by the voltage follower circuit, the resistance feedback module controls the resistance value of the inverting input end to decrease; when the potential of the analog data signal output by the digital-to-analog conversion circuit is less than the potential of the analog data signal output by the voltage follower circuit, the resistance feedback module controls the resistance value of the inverting input end to increase.

[0012] Optionally, the resistance feedback module comprises a first driving transistor, a third resistance, a fourth resistance and a comparator, the comparator comprises a third input end and a fourth input end, the output end of the digital-to-analog conversion circuit is connected to the third input end through the third resistance, and the output end of the voltage follower circuit is connected to the third input end through the fourth resistance; the fourth input end is connected to a ground signal end, and the output end of the comparator is connected to the control end of the first driving transistor; the input end of the first driving transistor is connected to the output end of the digital-to-analog conversion circuit, and the output end of the first driving transistor is connected to one end of the second resistance; when the potential of the analog data signal output by the digital-to-analog conversion circuit is greater than the absolute value of the potential of the analog data signal output by the voltage follower circuit, the potential of the voltage output by the comparator to the first driving transistor decreases, and the resistance value of the first driving transistor decreases; when the potential of the analog data signal output by the digital-to-analog conversion circuit is less than the absolute value of the potential of the analog data signal output by the voltage follower circuit, the potential of the voltage output by the comparator to the first driving transistor increases, and the resistance value of the first driving transistor increases.

[0013] Optionally, the resistance value of the first resistance is equal to the sum of the resistance value of the second resistance, the resistance value of the second active switch and the resistance value of the first driving transistor.

[0014] The application further discloses a display device comprising a display panel and the display panel driving circuit.

[0015] The application selects the first input end or the second input end of the voltage follower circuit to input the analog data signal according to the polarity of the digital data signal. When the required polarity is positive, the analog data signal is input from the first input end, so that the analog data signal with positive polarity is output; when the required polarity is negative, the analog data signal is input from the second input end, so that the analog data signal with negative polarity is output. The application outputs analog data signals with different polarities through positive or negative phase processing of the voltage follower circuit. Compared with the scheme of arranging two groups of digital-to-analog conversion circuits, the circuit design is simpler, the occupied space is smaller, the cost is lower and the like. BRIEF DESCRIPTION OF DRAWINGS

[0016] The accompanying drawings, which are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is to be understood that the drawings are solely for purposes of illustration and that they are not limiting of the application.

[0017] Figure 1 is a schematic diagram of a driving circuit of a display panel of the present application;

[0018] Figure 2 is an output schematic diagram of an analog data signal of the present application;

[0019] Figure 3 is a schematic diagram of another driving circuit of a display panel of the present application;

[0020] Figure 4 is a schematic diagram of a display device of the present application.

[0021] wherein 100, driving circuit; 110, control circuit; 120, digital-to-analog conversion circuit; 130, selection circuit; 140, voltage follower circuit; 141, operational amplifier; 150, resistance feedback module; 151, comparator; Vint+, positive input terminal; Vint-, negative input terminal; Vint3, third input terminal; Vint4, fourth input terminal; T1, first active switch; T2, second active switch; T3, third active switch; Q1, first drive transistor; Ref1, first resistor; Ref2, second resistor; R3, third resistor; R4, fourth resistor; output, output port; Polarity_P, first polarity adjustment signal; Polarity_N, second polarity adjustment signal; 200, display device; 210, display panel. DETAILED DESCRIPTION

[0022] It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting. It is to be understood that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting.

[0023] In the description of the present application, the terms "first", "second" are only used for the purpose of description, and cannot be understood as indicating relative importance, or implying the number of the indicated technical features. Therefore, unless otherwise specified, the features defined with "first", "second" can explicitly or implicitly include one or more of the features; the meaning of "multiple" is two or more. In addition, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "vertical", "horizontal" and the like are described based on the orientation or relative position relationship shown in the drawings, and are only for the convenience of the simplified description of the present application, and cannot be understood as indicating that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments.

[0025] Figure 1 is a schematic diagram of a driving circuit of a display panel of the present application, referring to Figure 1 As shown in the figure, the present application discloses a driving circuit 100 of a display panel, the display panel comprising a plurality of data lines, the driving circuit 100 comprising a plurality of control circuits 110 and a plurality of output ports output, each of the control circuits 110 being connected to one of the output ports output, and each of the output ports output being connected to one of the data lines; the control circuit 110 comprising a digital-to-analog conversion circuit 120, a selection circuit 130 and a voltage follower circuit 140, the digital-to-analog conversion circuit 120 being used to convert a digital data signal into an analog data signal and output the analog data signal to the selection circuit 130; the selection circuit 130 being used to output the analog data signal to the voltage follower circuit 140; the voltage follower circuit 140 being provided with a first input end and a second input end, and an output end of the voltage follower circuit 140 being connected to one of the output ports output; wherein the selection circuit 130 outputs the analog data signal to the first input end or the second input end according to the polarity of the digital data signal; when the analog data signal is output to the first input end, the output port output outputs an analog data signal of positive polarity, and when the analog data signal is output to the second input end, the output port output outputs an analog data signal of negative polarity.

[0026] The application selects the input of the analog data signal from the first input terminal or the second input terminal of the voltage follower circuit 140 according to the polarity of the digital data signal through the selection circuit 130. When the required polarity is positive, the analog data signal is output from the first input terminal, so that the positive polarity analog data signal is output. When the required polarity is negative, the analog data signal is output from the second input terminal, so that the negative polarity analog data signal is output. The application outputs analog data signals with different polarities through positive or negative phase processing of the voltage follower circuit 140, which has the advantages of simpler circuit design, smaller occupied space, lower cost and the like compared with the scheme of arranging two groups of digital-to-analog conversion circuits 120.

[0027] Specifically, the digital-to-analog conversion circuit 120 can also be referred to as a DAC circuit, which is usually designed in a resistance division type, and the number of resistors and the number of active switches have an exponential relationship with the data precision. For example, a 2-bit DAC circuit needs 3 resistors and 8 active switches when designed in a resistance division type. For example, a 4-bit DAC circuit needs 15 resistors and 64 active switches when designed in a resistance division type. A commonly used 8-bit DAC circuit needs 255 resistors and 2048 active switches when designed in a resistance division type. When the analog data signal with the polarity reversed needs to be output, two groups of DAC circuits are needed for one output port output to output the analog data signal with positive polarity or negative polarity. When two groups of DAC circuits are needed for one output port output, especially for 8-bit or 10-bit data, more resistors and active switches are needed, resulting in larger occupied space and higher cost.

[0028] In the embodiment, only one group of DAC circuits, i.e., one group of digital-to-analog conversion circuits 120, is needed, and each digital-to-analog conversion circuit 120 is connected to one output port output through the selection circuit 130 and the voltage follower circuit 140, thereby forming an output channel.

[0029] Specifically, only one digital-to-analog conversion circuit is arranged in each control circuit 110, which is used to convert the digital data signal with positive polarity or negative polarity into the analog data signal with positive polarity and output to the selection circuit 130. The digital-to-analog conversion circuit 120 is a positive digital-to-analog conversion circuit 120. Of course, in another embodiment, the digital-to-analog conversion circuit 120 can also be a negative digital-to-analog conversion circuit 120, i.e., the digital data signal with positive polarity or negative polarity is converted into the analog data signal with negative polarity and output to the selection circuit 130.

[0030] The driving circuit 100 in the embodiment is generally a data driving circuit 100, which is generally designed in a data driving chip, connected to a display panel by an external connection, and each output port output is connected to a data line to provide corresponding analog data signals for the data line. In the embodiment, only one set of digital-to-analog conversion circuit is used to transmit positive and negative analog data signals to the data line through the output port output, so as to realize polarity inversion of liquid crystal.

[0031] Specifically, the selection circuit 130 includes a first active switch T1 and a second active switch T2, a control end of the first active switch T1 is connected to a first polarity adjustment signal Polarity_P, and a control end of the second active switch T2 is connected to a second polarity adjustment signal Polarity_N; an input end of the first active switch T1 and an input end of the second active switch T2 are respectively connected to output ends of the digital-to-analog conversion circuit 120; the voltage follower circuit 140 includes an operational amplifier 141, the operational amplifier 141 includes a non-inverting input end Vint+ and an inverting input end Vint-, the first input end is the non-inverting input end Vint+, and the second input end is the inverting input end Vint-; an output end of the first active switch T1 is connected to the non-inverting input end Vint+, an output end of the second active switch T2 is connected to the inverting input end Vint-, and an output end of the operational amplifier 141 is connected to the output port output; when the digital data signal is positive, the first polarity adjustment signal Polarity_P is a working level, and the first active switch T1 is in a conductive state; when the digital data signal is negative, the second polarity adjustment signal Polarity_N is a working level, and the second active switch T2 is in a conductive state.

[0032] In the embodiment, by setting the first active switch T1 and the second active switch T2, the first polarity adjustment signal Polarity_P or the second polarity adjustment signal Polarity_N is generated according to the polarity of the digital data signal, the first active switch T1 is controlled to be conductive or non-conductive by the first polarity adjustment signal Polarity_P, and the second active switch T2 is controlled to be conductive or non-conductive by the second polarity adjustment signal Polarity_N. Through the action of the first active switch T1 and the second active switch T2, the analog data signal output by the digital-to-analog conversion circuit 120 is input to the operational amplifier 141 through the non-inverting input end or the inverting input end, and the operational amplifier 141 performs non-inverting or inverting output. The selection circuit 130 used in the application enables the analog data signal output by the digital-to-analog conversion circuit 120 to be selectively input from the non-inverting input end or the inverting input end of the operational amplifier 141, so as to output analog data signals with positive polarity or negative polarity.

[0033] Figure 2 is an output schematic diagram of the analog data signal of the present application, referring to Figure 2 , wherein the first polarity adjustment signal Polarity_P and the second polarity adjustment signal Polarity_N are a pair of differential signals, that is, when the first polarity adjustment signal Polarity_P is at a logic high level, the second polarity adjustment signal Polarity_N is at a logic low level; when the first polarity adjustment signal Polarity_P is at a logic low level, the second polarity adjustment signal Polarity_N is at a logic high level. The above-mentioned working level is the level that makes the active switch in the on state. For example, the active switch is an N-type active switch, which is in the on state at a logic high level and in the off state at a logic low level, and the corresponding working level is a logic high level. In the present embodiment, all active switches can be N-type active switches, which remain in the on state at a logic high level. Vin represents the analog data signal input to the operational amplifier 141, and Voutput is the analog data signal output by the operational amplifier 141. Among them, when the first polarity adjustment signal Polarity_P is at a logic high level and the second polarity adjustment signal Polarity_N is at a logic low level, Vin and Voutput are both positive polarity. When the first polarity adjustment signal Polarity_P is at a logic low level and the second polarity adjustment signal Polarity_N is at a logic high level, Vin is positive polarity and Voutput is negative polarity, and the absolute values of the two are equal.

[0034] It can be understood that the digital-to-analog conversion circuit 120 in the exemplary technology will generally also be provided with an operational amplifier 141 at the output end to enhance the strength of the analog data signal output by the digital-to-analog conversion circuit 120. In the present embodiment, by utilizing the inverting output function of the operational amplifier 141, the input channel of the analog data signal output from the digital-to-analog conversion circuit 120 is switched by the selection circuit 130, and when a negative polarity analog data signal is needed, it is input from the inverting input end, and when a positive polarity analog data signal is needed, it is input from the non-inverting input end.

[0035] Specifically, the selection circuit 130 further comprises a third active switch T3, the control end of the third active switch T3 is connected to the second polarity adjustment signal Polarity_N, the input end of the third active switch T3 is connected to the ground signal end, and the output end of the third active switch T3 is connected to the non-inverting input end, for connecting the non-inverting input end to the ground signal end when the second polarity adjustment signal Polarity_N is at the working level. Among them, the third active switch T3 mainly functions to ground the non-inverting input end when the analog data signal is input from the inverting input end, thereby realizing inverting output.

[0036] Specifically, in order to make the gain of the operational amplifier 141 at the positive output and the gain of the operational amplifier 141 at the negative output the same, the first resistor Ref1 and the second resistor Ref2 can be set. The voltage follower circuit 140 further comprises a first resistor Ref1 and a second resistor Ref2, one end of the first resistor Ref1 is connected to the inverting input terminal, the other end of the first resistor Ref1 is connected to the output terminal of the operational amplifier 141; one end of the second resistor Ref2 is connected to the output terminal of the digital-to-analog conversion circuit 120, the other end of the second resistor Ref2 is connected to the inverting input terminal.

[0037] Taking the first active switch T1, the second active switch T2 and the third active switch T3 as N-type active switches, the working level as a logic high level, the resistance value of the first resistor Ref1 as Ref1, and the resistance value of the second resistor Ref2 as Ref2 as an example: when outputting a digital data signal of negative polarity, the first polarity adjustment signal Polarity_P is a logic low level, the second polarity adjustment signal Polarity_N is a logic high level, the corresponding first active switch T1 is in a cut-off state, and the second active switch T2 and the third active switch T3 are respectively in a conductive state. At this time, the operational amplifier 141 is in an inverting output, and the corresponding amplification gain A = -Ref1 / Ref2. When the resistance value of the first resistor Ref1 is equal to the resistance value of the second resistor Ref2, the corresponding amplification gain is 1, at this time, the output of the operational amplifier 141 is equal to the output of the digital-to-analog conversion circuit 120, but the polarity is negative. When outputting a digital data signal of positive polarity, the first polarity adjustment signal Polarity_P is a logic high level, the second polarity adjustment signal Polarity_N is a logic low level, the corresponding first active switch T1 is in a conductive state, and the second active switch T2 and the third active switch T3 are respectively in a cut-off state. At this time, the operational amplifier 141 is in a non-inverting output, and the corresponding amplification gain A = 1 + Ref1 / Rg, Rg is generally a ground resistor, in this application, the Rg can be equivalent to infinity, so that the amplification gain is about 1, so that the output of the operational amplifier 141 is equal to the output of the digital-to-analog conversion circuit 120, and the polarity is positive.

[0038] According to the gain formula, without considering other impedances, in the case of making the resistance value of the first resistor Ref1 equal to the resistance value of the second resistor Ref2, the absolute value of the potential of the analog data signal of positive polarity or negative polarity output by the operational amplifier 141 is equal to the potential of the analog data signal output by the digital-to-analog conversion circuit 120. However, in practice, the inverting input terminal also has the resistance of the second active switch T2, in order to make the non-inverting gain equal to the inverting gain, the resistance value of the first resistor Ref1 can be greater than or equal to the resistance value of the second resistor Ref2.

[0039] Figure 3 is another schematic diagram of a driving circuit of a display panel of the present application, referring to Figure 3 As shown in FIG. 1, the driving circuit of the display panel of the present application comprises a voltage follower circuit 140, a digital-to-analog conversion circuit 120, a resistor feedback module 150, and a resistor input module 160. The voltage follower circuit 140 is connected to the digital-to-analog conversion circuit 120, and the resistor feedback module 150 is connected to the voltage follower circuit 140 and the digital-to-analog conversion circuit 120. The resistor input module 160 is connected to the resistor feedback module 150.

[0040] In the embodiment, the resistor feedback module 150 compares the absolute value of the potential of the analog data signal output by the digital-to-analog conversion circuit 120 with the absolute value of the potential of the analog data signal output by the voltage follower circuit 140. When the two absolute values are not equal, it proves that the gain is not equal to 1, and the resistance value of the inverting input terminal needs to be adjusted so that the gain is equal to 1.

[0041] Specifically, when the potential of the analog data signal output by the digital-to-analog conversion circuit 120 is greater than the potential of the analog data signal output by the voltage follower circuit 140, the resistor feedback module 150 controls the resistance value of the inverting input terminal to decrease; when the potential of the analog data signal output by the digital-to-analog conversion circuit 120 is less than the potential of the analog data signal output by the voltage follower circuit 140, the resistor feedback module 150 controls the resistance value of the inverting input terminal to increase.

[0042] In the embodiment, the resistance of the first resistor Ref1 and the resistance of the second resistor Ref2 and the second active switch T2 on the inverting input terminal affect the output of the corresponding gain. By setting the resistance feedback module 150, when the potential of the analog data signal output by the operational amplifier 141 is large, the gain is reduced to 1, and when the potential of the analog data signal output by the operational amplifier 141 is small, the gain is increased to 1. It can be understood that the resistance feedback module 150 is mainly used in the inverting output process. Since the gain of the non-inverting output is only related to the impedance of the first resistor Ref1, the resistance change of the inverting input terminal will not affect the output of the positive polarity analog data signal. In the inverting output process, the gain A is related to the resistance of the second resistor Ref2 and the second active switch T2 on the inverting input terminal, and thus the resistance on the inverting input terminal can be adjusted to adjust the gain. For example, a slide rheostat or an equivalent slide rheostat is set to adjust the resistance on the inverting input terminal.

[0043] Specifically, the embodiment provides a resistance feedback module 150 formed by a first drive transistor Q1 and a comparator 151. The resistance feedback module 150 includes the first drive transistor Q1, a third resistor R3, a fourth resistor R4, and the comparator 151. The comparator 151 includes a third input terminal Vint3 and a fourth input terminal Vint4. The output terminal of the digital-to-analog conversion circuit 120 is connected to the third input terminal Vint3 through the third resistor R3. The output terminal of the voltage follower circuit 140 is connected to the third input terminal Vint3 through the fourth resistor R4. The fourth input terminal Vint4 is connected to a ground signal terminal. The output terminal of the comparator 151 is connected to the control terminal of the first drive transistor Q1. The input terminal of the first drive transistor Q1 is connected to the output terminal of the digital-to-analog conversion circuit 120. The output terminal of the first drive transistor Q1 is connected to one end of the second resistor Ref2. The first drive transistor Q1 is arranged between the second resistor Ref2 and the output terminal of the digital-to-analog conversion circuit 120.

[0044] In this embodiment, the first drive transistor Q1 is regarded as an equivalent sliding rheostat, and the voltage change output by the comparator 151 changes the gate voltage of the first drive transistor Q1, so that the resistance of the first drive transistor Q1 changes. By connecting the output end of the digital-to-analog conversion circuit 120 to the third input end Vint3 through the third resistor R3, and connecting the output end of the voltage follower circuit 140 to the third input end Vint3 through the fourth resistor R4, since the analog data signal output by the digital-to-analog conversion circuit 120 has a positive polarity and the analog data signal output by the voltage follower circuit 140 has a negative polarity, the third resistor R3 and the fourth resistor R4 have an effect. When the absolute value of the potential of the analog data signal output by the voltage follower circuit 140 is large, the potential input to the third input end Vint3 is less than 0; when the absolute value of the potential of the analog data signal output by the voltage follower circuit 140 is small, the potential input to the third input end Vint3 is greater than 0.

[0045] At this time, the potential of the inverting input end (the potential of point A in the figure): .

[0046] The potential of the third input end Vint3 (the potential of point B in the figure): .

[0047] Wherein, Vin represents the analog data signal output by the digital-to-analog conversion circuit 120, which is generally a fixed value and is not affected by the load. Vin can also be understood as the voltage of the analog data signal output by the digital-to-analog conversion circuit 120 input to the inverting input end of the operational amplifier 141, and Voutput represents the absolute value of the voltage of the analog data signal output by the operational amplifier 141. Ref1 is the resistance value of the first resistor Ref1, Ref2 is the resistance value of the second resistor Ref2, Rq1 is the resistance value of the first drive transistor Q1, which is affected by the gate voltage of the first drive transistor Q1 and can be adjusted and changed, Rt2 is the resistance value of the second active switch T2, R3 is the resistance value of the third resistor R3, and R4 is the resistance value of the fourth resistor R4. Among them, the resistance value of the third resistor R3 is equal to the resistance value of the fourth resistor R4.

[0048] When the analog data signal output by the voltage follower circuit 140 is negative, when the potential of the analog data signal output by the digital-to-analog conversion circuit 120 is greater than the absolute value of the potential of the analog data signal output by the voltage follower circuit 140, due to the change in resistance of the inverting input end, V 反When the voltage of the analog data signal output by the digital-to-analog conversion circuit 120 is greater than the absolute value of the voltage of the analog data signal output by the voltage follower circuit 140, the comparator 151 amplifies the error in a positive direction, so that the voltage of the output to the first drive transistor Q1 increases, the resistance value of the first drive transistor Q1 increases, so that the voltage of V3 increases, and Voutput is equal to Vin.

[0049] Specifically, in order to ensure that the gain of the inverting output also tends to 1, the resistance value of the first resistor Ref1 can be defined as equal to the sum of the resistance value of the second resistor Ref2, the resistance value of the second active switch T2, and the resistance value of the first drive transistor Q1. By making the two equal, the inverting gain is equal to the non-inverting gain, and the inverting gain is prevented from being too high, which affects the voltage of the negative analog data signal.

[0050] Figure 4 is a schematic diagram of a display device of the present application, as shown in Figure 4 The display device 200 comprises a display panel 210 and the driving circuit 100 of the display panel in any of the above embodiments, wherein the driving circuit 100 is used to drive the display panel 210 to display.

[0051] It should be noted that the inventive concept of the present application can form a very large number of embodiments, but the length of the application file is limited and cannot list them one by one, so the above-described embodiments or technical features can be combined to form new embodiments without conflict. The combination of each embodiment or technical feature will enhance the original technical effect.

[0052] The above is a further detailed description of the present application in combination with specific optional embodiments, and the specific implementation of the present application cannot be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or replacements can be made, which should be regarded as falling within the protection scope of the present application.

Claims

1. A drive circuit of a display panel, characterized by, The display panel comprises a plurality of data lines, the driving circuit comprises a plurality of control circuits and a plurality of output ports, each control circuit is connected to an output port, and each output port is connected to a data line respectively; the control circuit comprises: a digital-to-analog conversion circuit for converting digital data signals into analog data signals and outputting the analog data signals to a selection circuit; the selection circuit for outputting the analog data signals to a voltage follower circuit; and the voltage follower circuit provided with a first input end and a second input end, and the output end of the voltage follower circuit is connected to an output port; wherein the selection circuit outputs the analog data signals to the first input end or the second input end according to the polarity of the digital data signals; when the analog data signals are output to the first input end, the output port outputs analog data signals of positive polarity, and when the analog data signals are output to the second input end, the output port outputs analog data signals of negative polarity.

2. The driving circuit of the display panel according to claim 1, wherein only one digital-to-analog conversion circuit is provided in each control circuit, the digital-to-analog conversion circuit is used for converting digital data signals of positive polarity or negative polarity into analog data signals of positive polarity and outputting the analog data signals to the selection circuit.

3. The driving circuit of the display panel according to claim 1, wherein the selection circuit comprises a first active switch and a second active switch, the control end of the first active switch is connected to a first polarity adjustment signal, and the control end of the second active switch is connected to a second polarity adjustment signal; the input end of the first active switch and the input end of the second active switch are respectively connected to the output end of the digital-to-analog conversion circuit; the voltage follower circuit comprises an operational amplifier, the operational amplifier comprises a non-inverting input end and an inverting input end, the first input end is the non-inverting input end, and the second input end is the inverting input end; the output end of the first active switch is connected to the non-inverting input end, the output end of the second active switch is connected to the inverting input end, and the output end of the operational amplifier is connected to the output port; when the digital data signals are of positive polarity, the first polarity adjustment signal is a working level, and the first active switch is in an on state; when the digital data signals are of negative polarity, the second polarity adjustment signal is a working level, and the second active switch is in an on state.

4. The driving circuit of the display panel according to claim 3, wherein the selection circuit further comprises a third active switch, the control end of the third active switch is connected to the second polarity adjustment signal, the input end of the third active switch is connected to a ground signal end, and the output end of the third active switch is connected to the non-inverting input end, so as to connect the non-inverting input end to the ground signal end when the second polarity adjustment signal is a working level; the voltage follower circuit further comprises a first resistor and a second resistor, one end of the first resistor is connected to the inverting input end, and the other end of the first resistor is connected to the output end of the operational amplifier; one end of the second resistor is connected to the output end of the digital-to-analog conversion circuit, and the other end of the second resistor is connected to the inverting input end.

5. The driving circuit of the display panel according to claim 4, wherein The resistance value of the first resistor is greater than or equal to the resistance value of the second resistor.

6. The driving circuit of a display panel according to claim 4, wherein The driving circuit further comprises a resistance feedback module, which receives an analog data signal output by the digital-to-analog conversion circuit and an analog data signal output by the voltage follower circuit, and controls the resistance value of the inverting input end according to the potential of the analog data signal output by the digital-to-analog conversion circuit and the potential of the analog data signal output by the voltage follower circuit.

7. The driving circuit of the display panel according to claim 6, wherein When the potential of the analog data signal output by the digital-to-analog conversion circuit is greater than the potential of the analog data signal output by the voltage follower circuit, the resistance feedback module controls the resistance value of the inverting input end to decrease. When the potential of the analog data signal output by the digital-to-analog conversion circuit is less than the potential of the analog data signal output by the voltage follower circuit, the resistance feedback module controls the resistance value of the inverting input end to increase.

8. The driving circuit of the display panel according to claim 7, wherein, The resistance feedback module comprises a first driving transistor, a third resistor, a fourth resistor and a comparator, the comparator comprises a third input end and a fourth input end, the output end of the digital-to-analog conversion circuit is connected to the third input end through the third resistor, and the output end of the voltage follower circuit is connected to the third input end through the fourth resistor. The fourth input end is connected to a ground signal end, and the output end of the comparator is connected to the control end of the first driving transistor. The input end of the first driving transistor is connected to the output end of the digital-to-analog conversion circuit, and the output end of the first driving transistor is connected to one end of the second resistor. When the potential of the analog data signal output by the digital-to-analog conversion circuit is greater than the absolute value of the potential of the analog data signal output by the voltage follower circuit, the potential of the voltage output by the comparator to the first driving transistor decreases, and the resistance value of the first driving transistor decreases. When the potential of the analog data signal output by the digital-to-analog conversion circuit is less than the absolute value of the potential of the analog data signal output by the voltage follower circuit, the potential of the voltage output by the comparator to the first driving transistor increases, and the resistance value of the first driving transistor increases.

9. The driving circuit of the display panel according to claim 8, wherein, The resistance value of the first resistor is equal to the sum of the resistance value of the second resistor, the resistance value of the second active switch and the resistance value of the first driving transistor.

10. A display device, characterized by comprising: The driving circuit of the display panel and the display panel of any one of claims 1-9, wherein the driving circuit is used for driving the display panel to display.

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