Pixel display driving circuit and display panel

Abstract

The invention belongs to the technical field of display, and provides a pixel driving circuit and a display panel, data voltage is accessed through a compensation circuit, the data voltage is compared with at least one reference voltage, a target voltage interval where the data voltage is located is judged according to a comparison result, and compensation direct current is output according to the target voltage interval; the pixel driving circuit responds to access of a selection signal and outputs a driving current according to the data voltage and the compensation direct current so as to lighten a light-emitting element; wherein the current of the compensation direct current is in negative correlation with a value in the target voltage interval; therefore, the driving capability of the line scanning driving circuit is enhanced, the possibility of influence of parasitic parameters RC on signals is reduced, and the accuracy of data voltage transmission is improved.

Description

Technical Field

[0001] The present application belongs to the field of display technology, and in particular, relates to a pixel display driving circuit and a display panel. Background Art

[0002] With the continuous advancement of technology, Organic Light-Emitting Diode (OLED) has gradually become a display technology that has attracted much attention. Currently, more and more display products use OLED as the display screen. Compared with the traditional liquid crystal display (LCD) display technology, OLED is self-luminous and does not require an additional backlight module, so the energy consumption is very low. In addition, OLED has many advantages such as high brightness, high contrast, wide viewing angle, fast response speed, simple manufacturing process, etc. They have been widely used in various display panels and have broad application prospects.

[0003] At present, OLED is driven by thin film field effect transistor (TFT). The RC delay caused by the parasitic parameters of the TFT device in the circuit causes the output pulse rising edge and falling edge to become longer, which will have a serious impact on the driving ability of the output pulse, thereby affecting the accuracy of OLED light emission. If the impact of RC delay is to be reduced, it is necessary to fundamentally solve it from the TFT process technology and materials, and develop high-conductivity interconnect materials for TFT metal gate and source and drain electrodes to reduce parasitic resistance; or reduce the overlapping area between the source, drain and gate in the TFT from the process, and reduce the parasitic capacitance of the TFT itself; in addition, it can also be optimized from the TFT layout design level to reduce the contact resistance in the contact hole between metals or the parasitic capacitance between different metal layers, so as to reduce the signal delay caused by parasitic RC. However, the improvement of these TFT process technology and materials is very complicated.

[0004] Therefore, it is urgent to provide a pixel display driving circuit to enhance the driving capability of the row scanning driving circuit, thereby reducing the influence of the parasitic parameter RC on the signal and improving the accuracy of data voltage transmission. Summary of the invention

[0005] The purpose of the present application is to provide a pixel display driving circuit and a display panel, aiming to enhance the driving capability of the row scanning driving circuit, thereby solving the problem of the influence of parasitic parameters RC on the signal and improving the accuracy of data voltage transmission.

[0006] An embodiment of the present application provides a pixel display driving circuit, comprising:

[0007] A compensation circuit is configured to receive a data voltage, compare the data voltage with at least one reference voltage, determine a target voltage interval of the data voltage according to the comparison result, and output a compensation DC current according to the target voltage interval;

[0008] A pixel driving circuit connected to the compensation circuit and configured to output a driving current to the light-emitting element according to the data voltage and the compensation direct current in response to access of a selection signal, so as to light up the light-emitting element;

[0009] The current of the compensation direct current is negatively correlated with the value in the target voltage range.

[0010] In one embodiment, the compensation circuit includes n comparators, n-1 P-type switch tubes, n N-type switch tubes, n-1 switch elements and n compensation modules;

[0011] The positive input terminal of the first comparator and the first terminals of the n-1 P-type switch tubes are used as the data voltage input terminal of the compensation circuit to connect the data voltage; the negative input terminal of the i-th comparator is used as the i-th reference voltage input terminal of the compensation circuit to connect the i-th reference voltage;

[0012] The output end of the i+1th comparator is connected to the control end of the i+1th P-type switch tube, the control end of the i+1th N-type switch tube and the control end of the i-th switch element; the output end of the first comparator is connected to the control end of the 1st P-type switch tube and the control end of the 1st N-type switch tube;

[0013] The first ends of the n N-type switch tubes also serve as the data voltage input end of the compensation circuit to access the data voltage;

[0014] The second ends of the n N-type switch tubes are commonly connected to the input end of the first compensation module;

[0015] The i-th switch element is connected between the i-th compensation module and the i+1-th compensation module;

[0016] The compensation module amplifies the current of the connected data voltage to output the data voltage after the current is amplified;

[0017] Wherein, i is a positive integer less than n, and n is a positive integer.

[0018] In one embodiment, the compensation module includes an even number of cascaded inverters; the first inverter to the last inverter are connected in sequence;

[0019] Wherein, the input terminal of the first inverter is used as the data voltage input terminal of the compensation module to access the data voltage;

[0020] The output end of the last inverter is used as the data voltage output end after current amplification of the compensation module to output the data voltage after current amplification.

[0021] In one embodiment, the first reference voltage to the nth reference voltage decrease in sequence.

[0022] In one embodiment, n is positively correlated with a transmission distance, where the transmission distance is a distance between a data voltage output terminal and the pixel driving circuit.

[0023] In one embodiment, the pixel display driving circuit further includes:

[0024] an amplifying circuit, connected to the pixel driving circuit and the compensation circuit, and configured to amplify the data voltage to output the amplified data voltage;

[0025] The compensation circuit is specifically configured to compare the amplified data voltage with at least one reference voltage, determine the target voltage interval of the data voltage according to the comparison result, and output the compensation direct current according to the target voltage interval.

[0026] In one embodiment, the pixel driving circuit comprises:

[0027] A first switch circuit is connected to the compensation circuit and configured to transmit the data voltage in response to access of the selection signal;

[0028] an energy storage circuit connected to the first switch circuit and the compensation circuit, and configured to be charged according to the data voltage, the compensation DC power and the power supply DC power to output an energy storage voltage;

[0029] The second switch circuit is connected to the first switch circuit, the energy storage circuit and the compensation circuit, and is configured to transmit the supply DC power according to the energy storage voltage to output the driving current.

[0030] In one embodiment, the first switch circuit includes a first field effect transistor, the second switch circuit includes a second field effect transistor, and the energy storage circuit includes a first capacitor.

[0031] In one embodiment, the pixel display driving circuit includes a plurality of groups of pixel driving components, and each pixel driving component includes one compensation circuit and a plurality of pixel driving circuits.

[0032] An embodiment of the present invention further provides a display panel, which includes the above-mentioned pixel display driving circuit and a light-emitting element.

[0033] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: since the compensation circuit is connected to the data voltage, the data voltage is compared with at least one reference voltage, and the target voltage interval of the data voltage is determined according to the comparison result, and the compensation direct current is output according to the target voltage interval; the pixel driving circuit responds to the connection of the selection signal, and outputs the driving current according to the data voltage and the compensation direct current to light up the light-emitting element; the superimposed data voltage and the compensation direct current are applied to the pixel driving circuit to output the driving current, thereby enhancing the driving capability of the row scanning driving circuit, thereby reducing the possibility of the parasitic parameter RC affecting the signal; and the current of the compensation direct current is negatively correlated with the value in the target voltage interval, thereby accelerating the charging and discharging of the RC circuit, while improving the accuracy of the current compensation of the pixel display driving circuit, improving the stability of the OLED light emitting brightness, and improving the accuracy of data voltage transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical invention in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of a structure of a pixel display driving circuit provided in an embodiment of the present application;

[0036] Figure 2 A schematic diagram of a first structure of a compensation circuit in a pixel display driving circuit provided in an embodiment of the present application;

[0037] Figure 3 Another structural schematic diagram of a pixel display driving circuit provided in an embodiment of the present application;

[0038] Figure 4 Another structural schematic diagram of a pixel display driving circuit provided in an embodiment of the present application;

[0039] Figure 5 Another structural schematic diagram of a pixel display driving circuit provided in an embodiment of the present application;

[0040] Figure 6 A second structural schematic diagram of a compensation circuit in a pixel display driving circuit provided in an embodiment of the present application;

[0041] Figure 7 A schematic diagram of a structure of a pixel driving circuit in a pixel display driving circuit provided in an embodiment of the present application;

[0042] Figure 8A partial exemplary circuit schematic diagram of a pixel display driving circuit provided in an embodiment of the present application;

[0043] Fig. 9 A partial exemplary circuit schematic diagram of a compensation module in a pixel display driving circuit provided in an embodiment of the present application;

[0044] Fig.10 A partial exemplary circuit schematic diagram of a pixel driving circuit in a pixel display driving circuit provided in an embodiment of the present application;

[0045] Fig.11 A waveform diagram of a selection signal provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0047] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0048] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0049] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0050] Figure 1 The structure diagram of the pixel display driving circuit provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0051] The pixel display driving circuit includes a compensation circuit 11 and a pixel driving circuit 12 .

[0052] The compensation circuit 11 is configured to receive the data voltage Dm, compare the data voltage Dm with at least one reference voltage Vrefi, determine the target voltage interval of the data voltage Dm according to the comparison result, and output the compensation DC according to the target voltage interval.

[0053] The pixel driving circuit 12 is connected to the compensation circuit 11 and is configured to output a driving current to the light-emitting element according to the data voltage Dm and the compensation direct current in response to the access of the selection signal Sn, so as to light up the light-emitting element.

[0054] The current of the compensation DC power is negatively correlated with the value in the target voltage range.

[0055] It should be noted that the selection signal Sn and the data voltage Dm can be provided by a digital circuit.

[0056] As an example but not a limitation, at least one reference voltage Vrefi includes a first reference voltage Vref1 to an nth reference voltage Vrefn which decrease in sequence, an interval greater than or equal to the first reference voltage Vref1 as the first voltage interval, an interval less than the first reference voltage Vref1 and greater than or equal to the second reference voltage Vref2 as the second voltage interval, an interval less than the second reference voltage Vref2 and greater than or equal to the third reference voltage Vref3 as the third voltage interval, and so on, an interval less than the n-1th reference voltage Vrefn-1 and greater than or equal to the nth reference voltage Vrefn as the n+1th voltage interval; the target voltage interval is one of the first voltage interval to the n+1th voltage interval. When the data voltage Dm is in the first voltage interval, the compensation DC is the minimum; when the data voltage Dm is in the N+1th voltage interval, the compensation DC is the maximum; that is, as the value in the voltage interval increases, the current of the compensation DC decreases; n is a positive integer, and i is a positive integer less than or equal to n.

[0057] By making the current of the compensation DC negatively correlated with the value in the target voltage range, the data voltage Dm is negatively correlated with the current of the compensation DC. On the rising edge, as the data voltage Dm increases, the compensation DC decreases; on the falling edge, the data voltage Dm decreases and the compensation DC increases. While accelerating the charging and discharging of the RC circuit, the accuracy of the current compensation of the pixel display driving circuit is improved, and the stability of the OLED light brightness is improved.

[0058] like Figure 2 As shown, the compensation circuit 11 includes n comparators Ui, n−1 P-type switch tubes Pi, n N-type switch tubes Ni, n−1 switch elements Ki and n compensation modules 111 .

[0059] The positive input terminal of the first comparator U1 and the first terminals of the n-1 P-type switch tubes Pi serve together as the data voltage input terminal of the compensation circuit 11 to connect the data voltage Dm; the negative input terminal of the i-th comparator Ui serves as the i-th reference voltage Vrefi input terminal of the compensation circuit 11 to connect the i-th reference voltage Vrefi.

[0060] The output end of the i+1th comparator Ui+1 is connected to the control end of the i+1th P-type switch tube Pi+1, the control end of the i+1th N-type switch tube Ni+1 and the control end of the i-th switch element Ki; the output end of the 1st comparator U1 is connected to the control end of the 1st P-type switch tube P1 and the control end of the 1st N-type switch tube N1.

[0061] The first terminals of the n N-type switch tubes Ni also serve as the data voltage input terminal of the compensation circuit 11 to access the data voltage Dm.

[0062] The second ends of the n N-type switch tubes Ni are commonly connected to the input end of the first compensation module 111 .

[0063] The i-th switching element Ki is connected between the i-th compensation module 111 and the (i+1)-th compensation module 111 .

[0064] The compensation module 111 amplifies the current of the input data voltage Dm to output the data voltage Dm after current amplification.

[0065] Wherein, i is a positive integer less than n, and n is a positive integer.

[0066] For example, when the data voltage Dm is greater than or equal to the first reference voltage Vref1, the first comparator U1 outputs a high-level signal to turn on the first N-type switch tube N1 and turn off the first P-type switch tube P1; the first compensation module 111 operates according to the data voltage Dm transmitted by the first N-type switch tube N1, and outputs the data voltage Dm2 after current amplification; the second comparator U2 to the nth comparator Un output a low-level signal, the second N-type switch tube N2 to the nth N-type switch tube Nn are turned off, the first switch element K1 to the n-1th switch element Kn-1 are turned off, and the second compensation module 111 to the nth compensation module 111 stop working, so the data voltage Dm is only amplified by the first current of the first compensation module 111 to output the compensated direct current to the pixel driving circuit 12.

[0067] When the data voltage Dm is greater than or equal to the second reference voltage Vref2 and less than the first reference voltage Vref1, the first comparator U1 outputs a low-level signal to turn off the first N-type switch tube N1 and turn on the first P-type switch tube P1; the second comparator U2 outputs a high-level signal to turn on the second N-type switch tube N2 and the first switch element K1 and turn off the second P-type switch tube P2; the first compensation module 111 and the second compensation module 111 are based on the data voltage Dm transmitted by the second N-type switch tube N2. The third comparator U3 to the nth comparator Un output a low level signal, the third N-type switch tube N3 to the nth N-type switch tube Nn are turned off, the second switch element K2 to the n-1th switch element Kn-1 are turned off, and the third compensation module 111 to the n-th compensation module 111 stop working, so the data voltage Dm is only amplified by the two-stage current of the first compensation module 111 and the second compensation module 111 to output the compensated direct current to the pixel driving circuit 12.

[0068] By analogy, when the data voltage Dm is greater than or equal to the third reference voltage Vref3 and less than the second reference voltage Vref2, the data voltage Dm is amplified by three levels of current through the first compensation module 111, the second compensation module 111 and the third compensation module 111 to output a compensated direct current to the pixel driving circuit 12; until the data voltage Dm is less than or equal to the n-1th reference voltage Vrefn-1 and greater than the nth reference voltage Vrefn, the data voltage Dm is amplified by n levels of current through n compensation modules 111 to output a compensated direct current to the pixel driving circuit 12.

[0069] The data voltage Dm is compared by n comparators Ui to determine the target voltage interval of the data voltage Dm, and the corresponding number of compensation modules 111 are turned on according to the target voltage interval to amplify the current of the data voltage Dm by the corresponding number of levels to output compensated direct current, thereby achieving a negative correlation between the current of the compensated direct current and the value in the target voltage interval.

[0070] As an example but not a limitation, the compensation module 111 includes an even number of cascaded inverters; the first inverter to the last inverter are connected in sequence.

[0071] The input end of the first inverter is used as the data voltage input end of the compensation module to receive the data voltage; the output end of the last inverter is used as the current-amplified data voltage output end of the compensation module to output the current-amplified data voltage.

[0072] The compensation module 111 is realized by an even number of cascaded inverters, and the circuit structure is simple and the cost is low.

[0073] It should be emphasized that the first reference voltage Vref1 to the nth reference voltage Vrefn decrease in sequence.

[0074] Since the first reference voltage Vref1 to the nth reference voltage Vrefn decrease in sequence, the smaller the data voltage Dm is, the more compensation circuits 11 are turned on, the more levels of current amplification of the data voltage Dm are, the larger the compensation DC current is, and the accuracy of current compensation of the pixel driving circuit is improved.

[0075] It is worth emphasizing that the pixel display driving circuit may include multiple groups of pixel driving components, each group of pixel driving components includes a compensation circuit and multiple pixel driving circuits. By sharing a part of the compensation circuit, the circuit can be simplified and the pixel aperture ratio can be improved, thereby reducing costs. For example, a row of pixel circuits share a compensation circuit. Figure 3 As shown, there are n rows of pixel circuits (light emitting elements 90), each row of pixel circuits includes m pixel circuits, n compensation circuits 11 correspond to n rows of pixel circuits one by one, each compensation circuit 11 is connected to m pixel driving circuits 12; corresponding to each row of pixel circuits, m pixel driving circuits 12 are connected to m pixel circuits one by one. It can be understood that the pixel display driving circuit 12 also includes a microprocessor 100.

[0076] The microprocessor 100 is configured to access the data voltages of each row of pixel circuits, and when the data voltages of more than half of the pixel circuits in each row of pixel circuits are less than a threshold value, output an enable signal and a target data voltage corresponding to each row of pixel circuits, wherein the target data voltage is an average value of the data voltages of the pixel circuits in each row of pixel circuits or a median of the data voltages of the pixel circuits in each row of pixel circuits; the compensation circuit 11 is specifically configured to access the target data voltage, compare the target data voltage with at least one reference voltage Vrefi according to the enable signal, determine the target voltage interval in which the target data voltage is located according to the comparison result, and output a compensated direct current according to the target voltage interval; thereby, each pixel driving circuit 12 outputs a driving current to each light-emitting element according to the data voltage Dm and the compensated direct current in response to the access of the selection signal, so as to light up each light-emitting element.

[0077] It should be noted that n is positively correlated with the transmission distance, which is the distance between the output terminal of the data voltage Dm and the pixel driving circuit 12 .

[0078] In a specific implementation, the greater the distance between the output terminal of the data voltage Dm and the pixel driving circuit 12, the greater the attenuation degree of the data voltage Dm, and the smaller the attenuated data voltage Dm, so more compensation modules 111 are required for compensation to amplify the current of the data voltage Dm by more levels.

[0079] As an example but not a limitation, starting from the chip on film (COF), the data voltage of the near-end pixel circuit has almost no attenuation, and no compensation circuit is required; the farthest end needs to set the maximum level (n) of compensation circuit, such as 3-level compensation; from near to far, the compensation circuit increases in sequence. In one embodiment, the display panel can be divided into zones according to the distance from the COF, and different zones use different compensation circuit designs. Figure 4 As shown, the pixel circuits on the display panel are divided into regions 1, 2 to k from near to far from the COF; the level of the compensation circuit corresponding to each region is positively correlated with the distance of each region from the COF; for example, region 1 can be set to no compensation, region 2 can be set to level 1 compensation, region 3 can be set to level 2 compensation, and region 4 can be set to level 3 compensation.

[0080] It is possible to set n to be positively correlated with the transmission distance, and to set each pixel driving component to include a compensation circuit and a plurality of pixel driving circuits, thereby further improving the aperture ratio, simplifying the circuit, and reducing the cost.

[0081] like Figure 5 As shown, the pixel driving circuit further includes an amplifier circuit 13 .

[0082] The amplifier circuit 13 is connected to the pixel driving circuit 12 and the compensation circuit 11 , and is configured to amplify the data voltage Dm to output the amplified data voltage Dm.

[0083] The compensation circuit 11 is specifically configured to compare the amplified data voltage Dm with at least one reference voltage Vrefi, determine the target voltage interval of the data voltage Dm according to the comparison result, and output the compensation DC according to the target voltage interval.

[0084] By amplifying the data voltage Dm and comparing the amplified data voltage Dm with at least one reference voltage Vrefi, each voltage interval is enlarged, which is beneficial to circuit parameter design and device selection and facilitates circuit design.

[0085] In such Figure 5 In the pixel display driving circuit shown in FIG. 1 , the compensation circuit 11 can be as follows: Figure 6 As shown, it includes n comparators Ui, n-1 P-type switch tubes Pi, n N-type switch tubes Ni, n-1 switch elements Ki and n compensation modules 111.

[0086] The positive input terminal of the first comparator U1 and the first terminals of the n-1 P-type switch tubes Pi serve together as the amplified data voltage input terminal of the compensation circuit 11 to connect the amplified data voltage Dm2; the inverting input terminal of the i-th comparator Ui serves as the i-th reference voltage input terminal of the compensation circuit 11 to connect the i-th reference voltage Vrefi.

[0087] The output end of the i+1th comparator Ui+1 is connected to the control end of the i+1th P-type switch tube Pi+1, the control end of the i+1th N-type switch tube Ni+1 and the control end of the i-th switch element Ki; the output end of the 1st comparator U1 is connected to the control end of the 1st P-type switch tube P1 and the control end of the 1st N-type switch tube N1.

[0088] The first ends of the n N-type switch tubes Ni serve together as the data voltage input end of the compensation circuit 11 to access the data voltage Dm.

[0089] The second ends of the n N-type switch tubes Ni are commonly connected to the input end of the first compensation module 111 .

[0090] The i-th switching element Ki is connected between the i-th compensation module 111 and the (i+1)-th compensation module 111 .

[0091] The compensation module 111 amplifies the current of the input data voltage Dm to output the data voltage Dm after current amplification.

[0092] Wherein, i is a positive integer less than n, and n is a positive integer.

[0093] It is worth noting that Figure 4 The compensation circuit 11 shown is similar to Figure 3 The difference of the compensation circuit 11 shown is that the positive phase input terminal of the first comparator Ui and the first terminals of n-1 P-type switch tubes Pi serve as the amplified data voltage Dm input terminal of the compensation circuit 11 to access the amplified data voltage Dm.

[0094] Therefore Figure 6 The n comparators Ui shown compare the amplified data voltage Dm, determine the target voltage range where the amplified data voltage Dm is located, and turn on the corresponding number of compensation modules 111 according to the target voltage range to amplify the current of the data voltage Dm by a corresponding number of levels to output compensated direct current, thereby achieving a negative correlation between the current of the compensated direct current and the value in the target voltage range.

[0095] like Figure 7 As shown, the pixel driving circuit 12 includes a first switch circuit 121 , a storage circuit 122 and a second switch circuit 123 .

[0096] The first switch circuit 121 is connected to the compensation circuit 11 and is configured to transmit the data voltage Dm in response to the access of the selection signal Sn.

[0097] The energy storage circuit 122 is connected to the first switch circuit 121 and the compensation circuit 11, and is configured to be charged according to the data voltage Dm, the compensation DC power and the power supply DC power to output an energy storage voltage.

[0098] The second switch circuit 123 is connected to the first switch circuit 121, the energy storage circuit 122 and the compensation circuit 11, and is configured to transmit the power supply DC according to the energy storage voltage to output the driving current.

[0099] It should be noted that the first switch circuit 121, the energy storage circuit 122 and the second switch circuit 123 are connected to the first node A. The compensation circuit is specifically configured to connect the data voltage in response to the voltage of the first node A being less than or equal to a preset value, compare the data voltage with at least one reference voltage, determine the target voltage interval of the data voltage according to the comparison result, and output the compensation DC according to the target voltage interval.

[0100] The pixel selection function and the pixel driving function are realized by the first switch circuit 121 , the energy storage circuit 122 and the second switch circuit 123 .

[0101] Figure 8 FIG. 1 shows a partial exemplary circuit structure of a pixel driving circuit in a pixel display driving circuit provided by an embodiment of the present invention. Fig. 9 FIG. 1 shows a partial exemplary circuit structure of a compensation module in a pixel display driving circuit provided by an embodiment of the present invention. Fig.10 A partial exemplary circuit structure of an amplifier circuit in a pixel display driving circuit provided by an embodiment of the present invention is shown. For the sake of convenience, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0102] like Figure 8 As shown, the first switch circuit 121 includes a first field effect transistor M1; the gate of the first field effect transistor M1 serves as a selection signal input terminal of the first switch circuit 121 to access the selection signal Sn; the drain of the first field effect transistor M1 serves as a data voltage input terminal of the first switch circuit 121 to access the data voltage Dm; the source of the first field effect transistor M1 serves as a data voltage output terminal of the first switch circuit 121 to output the data voltage Dm.

[0103] The second switch circuit 123 includes a second field effect transistor M2; the gate of the second field effect transistor M2 and the source of the second field effect transistor M2 serve as energy storage voltage input terminals of the second switch circuit 123, and are connected to the energy storage circuit 122 to access the energy storage voltage; the source of the second field effect transistor M2 also serves as a power supply DC input terminal of the second switch circuit 123 to access the power supply DC; the drain of the second field effect transistor M2 serves as a driving current output terminal of the second switch circuit 123, and is connected to the light-emitting element to output a driving current.

[0104] The energy storage circuit 122 includes a first capacitor C1. The first end of the first capacitor C1 serves as a power supply DC input end of the energy storage circuit 122 to access the power supply DC; the first end of the first capacitor C1 serves as a data voltage input end of the energy storage circuit 122 and a compensation DC input end of the energy storage circuit 122, connected to the first switch circuit 121 and the second switch circuit 123 to access the data voltage Dm and the compensation DC; the first end of the first capacitor C1 and the second end of the first capacitor C1 serve together as a storage voltage output end of the energy storage circuit 122, connected to the second switch circuit 123 to output the storage voltage.

[0105] like Fig. 9 As shown, the compensation module 111 includes a first inverter IVT1 and a second inverter IVT2; the input end of the first inverter IVT1 serves as a data voltage input end of the compensation module 111 to access the data voltage Dm; the output end of the first inverter IVT1 is connected to the input end of the second inverter IVT2; the output end of the second inverter IVT2 serves as a current-amplified data voltage output end of the compensation module 111 to access the current-amplified data voltage Dm; the power supply end of the first inverter IVT1 and the power supply end of the second inverter IVT2 are commonly connected to the first power supply VAA; the ground end of the first inverter IVT1 and the ground end of the second inverter IVT2 are commonly connected to the power ground.

[0106] like Fig.10 As shown, the amplifier circuit 13 includes an operational amplifier X1, a third field effect transistor M3, a first resistor R1, a second resistor R2 and a third resistor R3; the gate of the third field effect transistor M3 serves as a selection signal input terminal of the amplifier circuit 13, and is connected to the pixel driving circuit 12 to access the selection signal Sn; the drain of the third field effect transistor M3 serves as a data voltage input terminal of the amplifier circuit 13, and is connected to the pixel driving circuit 12 to access the data voltage Dm; the source of the third field effect transistor M3 is connected to the first end of the third resistor R3, the second end of the third resistor R3 is connected to the non-inverting input terminal of the operational amplifier X1, the inverting input terminal of the operational amplifier X1 is connected to the first end of the first resistor R1 and the first end of the second resistor R2, the second end of the first resistor R1 and the output terminal of the operational amplifier X1 serve together as the amplified data voltage output terminal of the amplifier circuit 13, and are connected to the compensation circuit 11 to output the amplified data voltage Dm2; the second end of the second resistor R2 is connected to the power ground.

[0107] The following is a combination of working principles Figures 8 to 10 As shown for further explanation:

[0108] It should be noted that in the relevant pixel driving circuit 12, the selection signal Sn controls the switch of the first field effect transistor M1, so that the first field effect transistor M1 transmits the data voltage Dm to the first node A to charge the first capacitor C1. The energy storage voltage across the first capacitor C1 controls the degree of conduction of the second field effect transistor M2, thereby controlling the magnitude of the output drive current of the second field effect transistor and controlling the brightness of the light-emitting element OLED. Since the parasitic resistance and parasitic capacitance will delay the scanning selection pulse (selection signal Sn) generated by the row scanning driving circuit, such as Fig.11 As shown, the accuracy of the data voltage Dm is affected, and the brightness of the light-emitting element is further affected.

[0109] In the present application, the selection signal Sn controls the switch of the first field effect transistor M1, so that the first field effect transistor M1 transmits the data voltage Dm to the first node A. Fig.10 As shown, the selection signal Sn controls the third field effect transistor M3 to be turned on, and the data voltage Dm is amplified by the operational amplifier X1 and output to the Figure 6 The non-inverting input terminals of the n comparators Ui shown, Figure 4 The n comparators Ui shown compare the amplified data voltage Dm, determine the target voltage range where the amplified data voltage Dm is located, and according to the target voltage range, turn on the corresponding number of compensation modules 111, amplify the current of the data voltage Dm by the corresponding number of levels, and output the compensated direct current, so that the current of the compensated direct current is negatively correlated with the value in the target voltage range; the data voltage Dm and the compensated direct current are superimposed to charge the first capacitor C1, and the energy storage voltage at both ends of the first capacitor C1 controls the degree of conduction of the second field effect tube M2, thereby controlling the magnitude of the output drive current of the second field effect tube and controlling the brightness of the light-emitting element OLED.

[0110] An embodiment of the present invention further provides a display panel, which includes the above-mentioned pixel display driving circuit and a light-emitting element.

[0111] In the embodiment of the present invention, a data voltage is connected through a compensation circuit, the data voltage is compared with at least one reference voltage, and a target voltage interval of the data voltage is determined according to the comparison result, and a compensated direct current is output according to the target voltage interval; the pixel driving circuit responds to the connection of a selection signal, and outputs a driving current according to the data voltage and the compensated direct current to light up the light-emitting element; the superimposed data voltage and the compensated direct current are applied to the pixel driving circuit to output the driving current, thereby enhancing the driving capability of the row scanning driving circuit, thereby reducing the possibility of the parasitic parameter RC affecting the signal; and the current of the compensated direct current is negatively correlated with the value in the target voltage interval, thereby accelerating the charging and discharging of the RC circuit, improving the accuracy of the current compensation of the pixel driving circuit, improving the stability of the OLED light emitting brightness, and improving the accuracy of data voltage transmission.

[0112] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0113] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A pixel display driving circuit, characterized in that: include: A compensation circuit is configured to receive a data voltage, compare the data voltage with at least one reference voltage, determine a target voltage interval of the data voltage according to the comparison result, and output a compensation DC current according to the target voltage interval; A pixel driving circuit connected to the compensation circuit and configured to output a driving current to the light-emitting element according to the data voltage and the compensation direct current in response to access of a selection signal, so as to light up the light-emitting element; The current of the compensation direct current is negatively correlated with the value in the target voltage range.

2. The pixel display driving circuit according to claim 1, characterized in that: The compensation circuit includes n comparators, n-1 P-type switch tubes, n N-type switch tubes, n-1 switch elements and n compensation modules; The non-inverting input terminal of the first comparator and the first terminals of n-1 P-type switch tubes are used together as the data voltage input terminal of the compensation circuit to access the data voltage; The inverting input terminal of the i-th comparator serves as the i-th reference voltage input terminal of the compensation circuit to access the i-th reference voltage; The output end of the i+1th comparator is connected to the control end of the i+1th P-type switch tube, the control end of the i+1th N-type switch tube and the control end of the i-th switch element; the output end of the first comparator is connected to the control end of the 1st P-type switch tube and the control end of the 1st N-type switch tube; The first ends of the n N-type switch tubes also serve as the data voltage input end of the compensation circuit to access the data voltage; The second ends of the n N-type switch tubes are commonly connected to the input end of the first compensation module; The i-th switch element is connected between the i-th compensation module and the i+1-th compensation module; The compensation module amplifies the current of the connected data voltage to output the data voltage after the current is amplified; Wherein, i is a positive integer less than n, and n is a positive integer.

3. The pixel display driving circuit according to claim 2, characterized in that: The compensation module comprises an even number of cascaded inverters; the first inverter to the last inverter are connected in sequence; Wherein, the input terminal of the first inverter is used as the data voltage input terminal of the compensation module to access the data voltage; The output end of the last inverter is used as the data voltage output end after current amplification of the compensation module to output the data voltage after current amplification.

4. The pixel display driving circuit according to claim 2, characterized in that: The first reference voltage to the nth reference voltage decrease in sequence.

5. The pixel display driving circuit according to claim 2, characterized in that: n is positively correlated with the transmission distance, and the transmission distance is the distance between the data voltage output terminal and the pixel driving circuit.

6. The pixel display driving circuit according to claim 1, characterized in that: The pixel driving circuit further includes: an amplifying circuit, connected to the pixel driving circuit and the compensation circuit, and configured to amplify the data voltage to output the amplified data voltage; The compensation circuit is specifically configured to compare the amplified data voltage with at least one reference voltage, determine the target voltage interval of the data voltage according to the comparison result, and output the compensation direct current according to the target voltage interval.

7. The pixel display driving circuit according to claim 1, characterized in that: The pixel driving circuit comprises: A first switch circuit is connected to the compensation circuit and configured to transmit the data voltage in response to access of the selection signal; an energy storage circuit connected to the first switch circuit and the compensation circuit, and configured to be charged according to the data voltage, the compensation DC power and the power supply DC power to output an energy storage voltage; The second switch circuit is connected to the first switch circuit, the energy storage circuit and the compensation circuit, and is configured to transmit the supply DC power according to the energy storage voltage to output the driving current.

8. The pixel display driving circuit according to claim 7, characterized in that: The first switch circuit includes a first field effect transistor, the second switch circuit includes a second field effect transistor, and the energy storage circuit includes a first capacitor.

9. The pixel display driving circuit according to any one of claims 1 to 8, characterized in that: The pixel driving circuit includes a plurality of groups of pixel driving components, and each pixel driving component includes one compensation circuit and a plurality of pixel driving circuits.

10. A display panel, characterized in that: The display panel comprises a pixel display driving circuit and a light-emitting element as claimed in any one of claims 1 to 9.

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