Voltage detection display circuit, driving method thereof, display panel and display equipment

Abstract

The invention discloses a voltage detection display circuit, a driving method of the voltage detection display circuit, a display panel and a display device, and relates to the technical field of display. An impedance measurement module in the circuit is set to provide pixel power supply voltage when a display driving module provides pixel power supply voltage through a voltage routing line radial pixel structure module from a power supply end to a power supply access point; determining the voltage routing impedance of the pixel structure module according to a preset voltage detection signal and the pixel power supply voltage, and transmitting the voltage routing impedance to the sensing routing; the display driving module is configured to obtain voltage routing impedance sent by the impedance measurement module through the sensing routing, determine compensation voltage according to normal display current of the pixel structure module and the voltage routing impedance, superpose the compensation voltage to pixel power supply voltage and then access the pixel power supply voltage to a power supply access point for normal display of the pixel structure module. The invention aims to solve the display problem of non-uniform brightness display caused by metal routing resistance so as to improve the display quality.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a voltage detection display circuit and a driving method thereof, a display panel, and a display device. Background Art

[0002] With the continuous development of display technology, OLED (Organic Light-Emitting Diode) products are widely used in many fields such as mobile phones, cars, central control, smart home, smart office, watches, bracelets, etc. Users also have higher requirements for the display quality of OLED products.

[0003] ELVDD is one of the key voltages that drives OLED pixels to emit light. It is generated by DDIC (Display Driver IC) and transmitted to each pixel position of the panel. However, during the transmission process, due to the resistance of the metal wiring, a voltage drop will occur when the current passes through, which is the IR Drop phenomenon. As the signal transmission distance increases, the voltage drop gradually accumulates, causing the ELVDD voltage received at the far end of the panel to be lower than that at the near end, which in turn causes uneven brightness and seriously affects the display quality of OLED products.

[0004] Therefore, how to improve the display quality of OLED products is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The main purpose of the present application is to provide a voltage detection display circuit and a driving method thereof, a display panel and a display device, aiming to improve the uniformity of the brightness display of OLED products.

[0006] To achieve the above-mentioned object, the present application provides a voltage detection display circuit, which includes a display driving module, an array-distributed pixel structure module, and an impedance measurement module and a sensing trace electrically connected to the pixel structure module; The power supply access point of the pixel structure module is electrically connected to the power supply end of the display driving module and the signal access end of the impedance measurement module respectively, and the signal output end of the impedance measurement module is electrically connected to the impedance detection end of the display driving module through the sensing wiring; The impedance measurement module is configured to determine the voltage routing impedance of the pixel structure module according to a preset voltage detection signal and the pixel power voltage when the display driving module radially provides the pixel power voltage to the pixel structure module through the voltage routing line from the power supply end to the power supply access point, and transmit the voltage routing impedance to the sensing routing; The display driving module is configured to obtain the voltage routing impedance sent by the impedance measurement module via the sensing routing, and determine a compensation voltage based on a normal display current of the pixel structure module and the voltage routing impedance, and superimpose the compensation voltage on the pixel power supply voltage and then connect it to the power supply access point so that the pixel structure module can display normally.

[0007] In one embodiment, the impedance measurement module includes a first thin film transistor and a voltage detection signal terminal; The gate of the first thin film transistor is electrically connected to the voltage detection signal terminal; The first channel end of the first thin film transistor constitutes a signal access end of the impedance measurement module and is electrically connected to a power supply access end of the pixel structure module; The second channel end of the first thin film transistor constitutes a signal output end of the impedance measurement module and is electrically connected to the sensing trace.

[0008] In one embodiment, the display driving module includes a detection switching unit, an impedance detection unit, a sensing unit and a timing control unit; The sensing end of the detection switching unit is electrically connected to the sensing unit, the detection end of the detection switching unit is electrically connected to the impedance detection unit, and the control end of the detection switching unit is electrically connected to the timing control unit; The signal acquisition end of the detection switching unit constitutes the impedance detection end of the display driving module and is electrically connected to the sensing wiring.

[0009] In one embodiment, the detection switching unit includes an N-type MOS tube and a P-type MOS tube; The gate of the N-type MOS tube is electrically connected to the gate of the P-type MOS tube, and the connection node where the gate of the N-type MOS tube is electrically connected to the gate of the P-type MOS tube constitutes the control end of the detection switching unit and is electrically connected to the timing control unit; The first channel end of the N-type MOS tube constitutes the sensing end of the detection switching unit and is electrically connected to the sensing unit, and the first channel end of the P-type MOS tube constitutes the detection end of the detection switching unit and is electrically connected to the impedance detection unit; The second passage end of the N-type MOS tube is electrically connected to the second passage end of the P-type MOS tube, and the connection intersection where the second passage end of the N-type MOS tube is electrically connected to the second passage end of the P-type MOS tube constitutes the signal collection end of the detection switching unit and is electrically connected to the sensing wiring.

[0010] In one embodiment, the impedance detection unit includes an impedance test component and a storage component, and the impedance test component is electrically connected to the storage component and the detection end of the detection switching unit respectively.

[0011] In one embodiment, the pixel structure module includes a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a capacitor and a light emitting diode; The gate of the second thin film transistor is electrically connected to a preset first signal terminal, the first channel terminal of the second thin film transistor is electrically connected to a data line, the second channel terminal of the second thin film transistor is electrically connected to the gate of the third thin film transistor, and the first terminal of the capacitor is arranged between the second channel terminal of the second thin film transistor and the gate of the third thin film transistor; The first channel end of the third thin film transistor is electrically connected to the power supply end, the second end of the capacitor is arranged between the first channel end of the third thin film transistor and the power supply end, the second channel end of the third thin film transistor is electrically connected to the anode of the light emitting diode, and the cathode of the light emitting diode is electrically connected to the negative power supply end; The gate of the fourth thin film transistor is electrically connected to a preset second signal terminal, the first channel terminal of the fourth thin film transistor is arranged between the second channel terminal of the third thin film transistor and the anode of the light emitting diode, and the second channel terminal of the fourth thin film transistor is electrically connected to the sensing trace.

[0012] In addition, to achieve the above-mentioned purpose, the present application also provides a driving method of a voltage detection display circuit, and the driving method of the voltage detection display circuit is applied to any of the voltage detection display circuits described above, and the driving method of the voltage detection display circuit includes: When the display driving module provides a pixel power supply voltage to the pixel structure module through a voltage routing line from a power supply end to a power supply access point, the voltage routing impedance of the pixel structure module is determined according to a preset voltage detection signal and the pixel power supply voltage by an impedance measurement module, and the voltage routing impedance is transmitted to a sensing routing by the impedance measurement module; The voltage routing impedance sent by the impedance measurement module via the sensing routing is obtained through the display driving module, and a compensation voltage is determined based on the normal display current of the pixel structure module and the voltage routing impedance. The compensation voltage is superimposed on the pixel power supply voltage and then connected to the power supply access point to allow the pixel structure module to display normally.

[0013] In one embodiment, the step of obtaining, by the display driving module, the voltage line impedance sent by the impedance measurement module via the sensing line comprises: Accessing the actual routing impedance output by the sensing routing through the display driving module, and determining the sensing routing impedance corresponding to the sensing routing and the number of paths of the voltage routing path; An impedance difference between the actual routing impedance and the sensing routing impedance is determined, and ratio data between the impedance difference and the number of paths is used as the voltage routing impedance sent by the impedance measurement module.

[0014] In addition, to achieve the above-mentioned purpose, the present application also provides a display panel, and the display panel includes any of the voltage detection and display circuits described above.

[0015] In addition, to achieve the above-mentioned purpose, the present application also provides a display device, the display device includes the above-mentioned display panel; or, The display device includes a processor, a memory, and a driver program of a voltage detection display circuit stored in the memory and executable by the processor, wherein when the driver program of the voltage detection display circuit is executed by the processor, the steps of the driving method of the voltage detection display circuit are implemented.

[0016] The present application provides a voltage detection display circuit and its driving method, display panel and display device, which significantly improve the display quality of OLED products applied to the voltage detection display circuit. Specifically, the voltage detection display circuit provided in the present application integrates a display driving module, an array-distributed pixel structure module, and an impedance measurement module and a sensing wiring electrically connected to the pixel structure module. The power supply access points of the pixel structure module are electrically connected to the power supply end of the display driving module. In the process of the display driving module providing the pixel power supply voltage through the voltage wiring path from the power supply end to the power supply access point to drive the pixel structure module to emit light, the impedance measurement module electrically connected to the power supply access point can respond to the preset voltage detection signal, and monitor the voltage drop (i.e., IRDrop phenomenon) caused by the voltage wiring path (i.e., metal wiring) in real time, so that the voltage wiring impedance (i.e., metal wiring resistance) of the pixel structure module can be quickly and accurately obtained, and the voltage wiring impedance (i.e., metal wiring resistance) of the pixel structure module can be obtained. The voltage routing impedance is transmitted to the sensing routing electrically connected to the signal output end of the impedance measurement module. At this time, the sensing routing is electrically connected to the impedance detection end of the display driving module. After the display driving module is connected to the voltage routing impedance sent by the impedance measurement module via the sensing routing, the compensation voltage can be accurately obtained according to the voltage routing impedance and the normal display current of the pixel structure module. The compensation voltage is then superimposed on the pixel power supply voltage and then connected to the power supply access point of the pixel structure module, thereby avoiding the voltage drop phenomenon caused by the metal routing resistance and preventing the cumulative effect of the voltage drop, so that the pixel power supply voltage received by each pixel structure module distributed in the array is consistent, which significantly improves the brightness uniformity of the OLED product, thereby improving the display quality of the OLED product. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0019] Figure 1 is a schematic diagram showing uneven brightness of a display panel; Figure 2 It is the distribution diagram of ELVDD in the existing technology surface; Figure 3 It is a structural block diagram of the first embodiment of the voltage detection and display circuit of the present application; Figure 4 It is a wiring diagram of ELVDD in a plane involved in an embodiment of the voltage detection and display circuit of the present application; Figure 5 is a circuit diagram of an embodiment of a voltage detection and display circuit of the present application; Figure 6 is a schematic diagram of a display driving module involved in an embodiment of a voltage detection display circuit of the present application; Figure 7 It is a simplified schematic diagram of the actual wiring impedance involved in an embodiment of the voltage detection and display circuit of the present application; Figure 8 It is a schematic diagram of voltage routing impedance calculation involved in the driving method of the voltage detection and display circuit of the present application; Fig. 9 It is a schematic diagram of the structure of the display device involved in the embodiment of the present application.

[0020] Description of Figure Numbers: 10. Display driving module; 20. Impedance measurement module; 30. Pixel structure module; Ls. Sensing wiring; T1. First thin film transistor; 101. Detection switching unit; 102. Impedance detection unit; 103. Sensing unit; 104. Timing control unit; T2. Second thin film transistor; T3. Third thin film transistor; T4. Fourth thin film transistor; C1. Capacitor; D1. Light emitting diode; Q1. N-type MOS tube; Q2. P-type MOS tube.

[0021] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), such directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0025] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0026] ELVDD is an important voltage signal for display panels, especially OLED (Organic Light-Emitting Diode) screens, i.e., pixel power supply voltage, which is usually generated by DDIC (Display Driver IC). DDIC serves as a bridge between the upper application processor (CPU) and the OLED screen, and is responsible for converting image signals into control waveforms that the screen can receive. In this process, ELVDD is one of the key voltages that drives OLED pixels to emit light, and its stability and uniformity have an important impact on the display effect.

[0027] However, in practical applications, reference Figure 1 , Figure 1This is a schematic diagram showing uneven brightness of the display panel. After ELVDD is generated from DDIC, it needs to be transmitted to each pixel position of the panel through a complex circuit layout and metal wiring. Due to the resistance of the metal wiring, a voltage drop will occur when current passes through, which is the IR Drop phenomenon. As the signal transmission distance increases, the voltage drop gradually accumulates, causing the ELVDD voltage received at the far end of the panel to be lower than that at the near end, which in turn causes Figure 1 The problem of uneven brightness is shown. Figure 2 , Figure 2 is the distribution diagram of ELVDD in the existing technology. Figure 2 It can be seen that ELVDD is routed from far to near on the frame, and then enters the power supply access point of each pixel structure module in units of rows. Due to the voltage routing impedance Rp on the voltage routing path, the ELVDD voltages at the near and far ends will be inconsistent. For example, the farthest voltage Vn = the nearest voltage V1 + I* (nRp), n is the number of rows; this will cause the near-end pixels to appear too bright due to the high voltage, and the far-end pixels to appear too dark due to insufficient voltage. Especially when displaying pure white 255 grayscale, this brightness difference may be as high as hundreds of nits (brightness units). This brightness loss will cause the display screen yield to decrease, seriously affecting the display quality.

[0028] In order to solve the display problem of uneven brightness display caused by metal wiring resistance, the present application provides a voltage detection display circuit and a driving method thereof, a display panel and a display device.

[0029] The present application embodiment provides a voltage detection and display circuit, referring to Figure 3 As shown, Figure 3 It is a structural block diagram of the first embodiment of the voltage detection display circuit of the present application. The voltage detection display circuit includes a display driver module 10, an array-distributed pixel structure module 30, and an impedance measurement module 20 and a sensing line Ls electrically connected to the pixel structure module 30. The power supply access point of the pixel structure module 30 is electrically connected to the power supply end of the display driver module 10 and the signal access end of the impedance measurement module 20, respectively. The signal output end of the impedance measurement module 20 is electrically connected to the impedance detection end of the display driver module 10 through the sensing line Ls.

[0030] In the present embodiment, an impedance measurement module 20 is provided at the power supply access point of each pixel structure module 30, and the signal access end of the impedance measurement module 20 is electrically connected to the power supply access point of the corresponding pixel structure module 30. When the display driving module 10 provides the pixel power supply voltage to each pixel structure module 30 row by row, the impedance measurement module 20 electrically connected to each pixel structure module 30 confirms the voltage routing impedance between the power supply end of the display driving module 10 and the corresponding pixel structure module 30; next, the signal output end of each impedance measurement module 20 is electrically connected to the impedance detection end of the display driving module 10 through the sensing wiring Ls. After the display driving module 10 obtains the voltage routing impedance sent by each impedance measurement module 20 uploaded via the sensing wiring Ls, the pixel power supply voltage is compensated according to the voltage routing impedance and the normal display current of the pixel structure module 30, so that the pixel power supply voltage received by each pixel structure module 30 distributed in the array is kept consistent, which significantly improves the brightness uniformity of the OLED product, thereby improving the display quality of the OLED product.

[0031] It should be noted that there are multiple pixel structure modules 30, and multiple pixel structure modules 30 in the same row can be represented by pixel structure module 30-1, pixel structure module 30-2,..., and pixel structure module 30-N, and the impedance measurement module 20 corresponding to the pixel structure module 30-1 is -1, the impedance measurement module 20 corresponding to the pixel structure module 30-2 is -2,..., and the impedance measurement module 20 corresponding to the pixel structure module 30-N is -N.

[0032] The pixel supply voltage can be Figure 3 The ELVDD shown is indicated. For example, refer to Figure 4 , Figure 4 1 is a wiring diagram of ELVDD in a plane according to an embodiment of the voltage detection and display circuit of the present application. Figure 4 The minimum control unit shown is a pixel structure module 30 and an impedance measurement module 20 that are electrically connected. Figure 4 (a) indicates that the display driving module 10 is provided with two power supply terminals, namely, two ELVDD voltage injection points; that is, current is provided to the minimum control unit through the two ELVDD voltage injection points; Figure 4 (b) indicates that only the ELVDD voltage injection point on the left provides current to the minimum control unit; Figure 4 (c) indicates that only the ELVDD voltage injection point on the right provides current to the smallest control unit; that is, there is at least one voltage routing path from the power supply end to the power supply access point. In addition, Figure 4 The ELVDD wiring shown in the plane is only a feasible implementation of the present application, and the present application does not impose any limitation on this. Figure 4It can be seen that the sensing line Ls provided in the present application is relatively simple, and is only a sensing line with conductive properties, that is, there is only one sensing line Ls electrically connected to the minimum control unit.

[0033] The impedance measurement module 20 is configured to determine the voltage routing impedance of the pixel structure module 30 according to a preset voltage detection signal and the pixel power supply voltage when the display driving module 10 radially provides the pixel power supply voltage to the pixel structure module 30 through the voltage routing line from the power supply end to the power supply access point, and transmit the voltage routing impedance to the sensing routing Ls.

[0034] In the present embodiment, when the display driving module 10 provides the pixel power supply voltage to the radial pixel structure module 30 via the voltage routing line from the power supply end to the power supply access point, the voltage routing impedance when the pixel power supply voltage is output via the voltage routing path from the power supply end to the power supply access point is determined according to the response of the impedance measurement module 20 to the preset voltage detection signal, and then the voltage routing impedance is transmitted to the display driving module 10 through the sensing routing Ls, thereby realizing the real-time and accurate monitoring of the voltage routing impedance by the display driving module 10, providing reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0035] The display driving module 10 is configured to obtain the voltage routing impedance sent by the impedance measurement module 20 via the sensing routing Ls, and determine a compensation voltage based on the normal display current of the pixel structure module 30 and the voltage routing impedance, and superimpose the compensation voltage on the pixel power supply voltage and then connect it to the power supply access point so that the pixel structure module 30 can display normally.

[0036] In this embodiment, the sensing line Ls is electrically connected to the impedance detection end of the display driving module 10. After the display driving module 10 is connected to the voltage line impedance sent by the impedance measurement module 20 via the sensing line Ls, the compensation voltage can be accurately obtained according to the voltage line impedance and the normal display current of the pixel structure module 30. The compensation voltage is then superimposed on the pixel power supply voltage and then connected to the power supply access point of the pixel structure module 30, ensuring that each pixel structure module 30 distributed in the array can obtain a voltage that just meets its normal display requirements, that is, the pixel power supply voltage received by each pixel structure module 30 distributed in the array is consistent. This significantly improves the brightness uniformity of the display panel.

[0037] In summary, the present application provides a voltage detection display circuit and its driving method, a display panel and a display device, which significantly improve the display quality of OLED products applied to the voltage detection display circuit. Specifically, the voltage detection display circuit provided in the present application integrates a display driving module 10, an array-distributed pixel structure module 30, and an impedance measurement module 20 and a sensing trace Ls corresponding to the pixel structure module 30. The power supply access points of the pixel structure module 30 are electrically connected to the power supply end of the display driving module 10. In the process of the display driving module 10 providing the pixel power supply voltage to drive the pixel structure module 30 to emit light through the voltage trace path from the power supply end to the power supply access point, the impedance measurement module 20 electrically connected to the power supply access point can respond to the preset voltage detection signal to monitor the voltage drop (i.e., IR) caused by the voltage trace path (i.e., the metal trace) in real time. Drop phenomenon), so that the voltage routing impedance (i.e., metal routing resistance) of the pixel structure module 30 can be quickly and accurately obtained, and the voltage routing impedance is transmitted to the sensing routing Ls electrically connected to the signal output end of the impedance measurement module 20. At this time, according to the electrical connection between the sensing routing Ls and the impedance detection end of the display driving module 10, after the display driving module 10 is connected to the voltage routing impedance sent by the impedance measurement module 20 via the sensing routing Ls, the compensation voltage can be accurately obtained according to the voltage routing impedance and the normal display current of the pixel structure module 30, and then the compensation voltage is superimposed on the pixel power supply voltage and then connected to the power supply access point of the pixel structure module 30, thereby avoiding the voltage drop phenomenon caused by the metal routing resistance and preventing the cumulative effect of the voltage drop, so that the pixel power supply voltage received by each pixel structure module 30 distributed in the array is consistent, which significantly improves the brightness uniformity of the OLED product, thereby improving the display quality of the OLED product.

[0038] Further, in some feasible embodiments, referring to Figure 5 , Figure 5 This is a circuit diagram of an embodiment of the voltage detection display circuit of the present application. The impedance measurement module 20 includes a first thin film transistor T1 and a voltage detection signal terminal; the gate of the first thin film transistor T1 is electrically connected to the voltage detection signal terminal; the first channel terminal of the first thin film transistor T1 constitutes the signal access terminal of the impedance measurement module 20, and is electrically connected to the power supply access terminal of the pixel structure module 30; the second channel terminal of the first thin film transistor T1 constitutes the signal output terminal of the impedance measurement module 20, and is electrically connected to the sensing trace Ls.

[0039] In the present embodiment, when the gate of the first thin film transistor T1 is connected to the preset voltage detection signal Y1, the first thin film transistor T1 is immediately switched from the off state to the on state, so that the pixel power supply voltage outputted from the voltage wiring path from the power supply end to the power supply access point can be input to the impedance detection end of the display driving module 10 through the sensing wiring Ls through the first thin film transistor T1, so that the display driving module 10 can accurately obtain the voltage wiring impedance of the pixel structure module 30, which provides reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0040] In a specific embodiment, if the preset voltage detection signal Y1 changes from a low level to a high level, the gate of the first thin film transistor T1 responds to the voltage detection signal, thereby switching the first thin film transistor T1 from a cut-off state to a conduction state.

[0041] Further, in some other feasible embodiments, referring to Figure 6 , Figure 6 1 is a schematic diagram of a display driver module 10 involved in an embodiment of a voltage detection display circuit of the present application. The display driver module 10 includes a detection switching unit 101, an impedance detection unit 102, a sensing unit 103 and a timing control unit 104; the sensing end of the detection switching unit 101 is electrically connected to the sensing unit 103, the detection end of the detection switching unit 101 is electrically connected to the impedance detection unit 102, and the control end of the detection switching unit 101 is electrically connected to the timing control unit 104; the signal acquisition end of the detection switching unit 101 constitutes the impedance detection end of the display driver module 10, and is electrically connected to the sensing trace Ls.

[0042] In this embodiment, if the timing control signal output by the timing control unit 104 switches from a high level to a low level, the detection switching unit 101 responds to the timing control signal representing the low level, connects the connection path from the impedance detection unit 102 to the sensing trace Ls, and enables the detection switching unit 101 to access the actual trace impedance output by the sensing trace Ls; next, after determining the sensing trace Ls impedance of the sensing trace Ls, based on the impedance difference between the actual trace impedance and the sensing trace Ls impedance, and the ratio data between the number of paths of the voltage trace path, the voltage trace impedance sent by the impedance measurement module 20 can be accurately calculated, thereby providing reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0043] It should be noted that the display driver module 10 can be understood as a DDIC (Display Driver IC, display driver chip).

[0044] The actual trace impedance can be Figure 7 The R_all shown in the figure indicates that the actual trace impedance is the total impedance between the voltage trace impedance ELVDD_R and the sensor trace impedance sensor_R. In addition, Figure 7 The RI_O shown can be understood as the starting point of the DDIC output ELVDD voltage (i.e., pixel power supply voltage); Figure 7 The RI_I shown can be understood as the input end of the sensing trace LsIC (i.e., the impedance detection end of the display driver module 10); Figure 7 The test point T shown is a connection node where the signal input terminal of the impedance measurement module 20 is electrically connected to the power supply access point of the pixel structure module 30 .

[0045] In a specific embodiment, the sensor line Ls impedance sensor_R set in the present application can be a preset value, which can be customized according to application requirements; the sensor line Ls impedance sensor_R can also be calculated according to a preset impedance calculation formula, wherein the preset impedance calculation formula is shown in the following formula (1).

[0046] sensor_R= ...Formula (1) in, It represents the resistivity, which is strongly related to the conductor material of the sensing trace Ls; L represents the line length, that is, the distance between the input end of the sensing trace LsIC of the DDIC and the test point T; Represents the cross-sectional area of ​​the sensing trace Ls; , L and All of them are definite values. According to the impedance calculation formula, the impedance sensor_R of the sensing line Ls of each pixel structure module 30 can be accurately calculated.

[0047] Further, in some feasible embodiments, referring to Figure 6The detection switching unit 101 includes an N-type MOS transistor Q1 and a P-type MOS transistor Q2; the gate of the N-type MOS transistor Q1 is electrically connected to the gate of the P-type MOS transistor Q2, and the connection node where the gate of the N-type MOS transistor Q1 is electrically connected to the gate of the P-type MOS transistor Q2 constitutes the control end of the detection switching unit 101 and is electrically connected to the timing control unit 104; the first channel end of the N-type MOS transistor Q1 constitutes the sensing end of the detection switching unit 101 and is electrically connected to the sensing unit 103, and the first channel end of the P-type MOS transistor Q2 constitutes the detection end of the detection switching unit 101 and is electrically connected to the impedance detection unit 102; the second channel end of the N-type MOS transistor Q1 is electrically connected to the second channel end of the P-type MOS transistor Q2, and the connection intersection where the second channel end of the N-type MOS transistor Q1 is electrically connected to the second channel end of the P-type MOS transistor Q2 constitutes the signal acquisition end of the detection switching unit 101 and is electrically connected to the sensing trace Ls.

[0048] In this embodiment, the detection switching unit 101 provided in the present application is used to switch whether the sensing line Ls is in the Vth sensing stage or the ELVDD impedance detection stage. Exemplarily, when the timing control signal output by the timing control unit 104 is at a high level, the P-type MOS tube Q2 maintains the off state, and the N-type MOS tube Q1 switches from the off state to the on state to connect the connection path from the sensing unit 103 to the sensing line Ls, that is, the sensing line Ls is in the Vth sensing stage, that is, Figure 5 The fourth thin film transistor T4 shown is switched from a cut-off state to a conducting state under the drive of a sensing signal output from a preset second signal terminal, so that the display driving module 10 electrically connected to the sensing trace Ls can detect the current flowing through the third thin film transistor T3 or the anode potential of the light emitting diode D1, thereby calculating the threshold voltage of the third thin film transistor T3.

[0049] When the timing control signal output by the timing control unit 104 switches from a high level to a low level, the detection switching unit 101 responds to the timing control signal representing the low level, enables the N-type MOS tube Q1 to switch from the on state to the off state, and synchronously switches the P-type MOS tube Q2 from the off state to the on state to connect the connection path from the impedance detection unit 102 to the sensing trace Ls, so as to enable the detection switching unit 101 to access the actual trace impedance output by the sensing trace Ls; next, after determining the sensing trace Ls impedance of the sensing trace Ls, according to the impedance difference between the actual trace impedance and the sensing trace Ls impedance, and the ratio data between the number of paths of the voltage trace path, the voltage trace impedance sent by the impedance measurement module 20 can be accurately calculated, thereby providing reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0050] Further, in some other feasible embodiments, referring to Figure 6 The impedance detection unit 102 includes an impedance test component and a storage component, and the impedance test component is electrically connected to the storage component and the detection end of the detection switching unit 101 respectively.

[0051] In this embodiment, the impedance testing component provided in the present application is an ELVDD routing impedance module, which is configured to, after determining the sensing routing Ls impedance of the sensing routing Ls, accurately calculate the voltage routing impedance sent by the impedance measurement module 20 based on the impedance difference between the actual routing impedance and the sensing routing Ls impedance and the ratio data between the number of paths of the voltage routing path, thereby providing reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0052] Exemplarily, according to the electrical connection between the impedance test component and the storage component, after the impedance test component determines the impedance value of the voltage wiring impedance, the impedance value of the voltage wiring impedance is sent to the storage component for storage. In addition, the storage component provided in the present application can be understood as a DRAM (Dynamic Random Access Memory), which is used to store the ELVDD impedance value (i.e., the impedance value of the voltage wiring impedance) of each pixel structure module 30. The expression of the ELVDD impedance value is shown in formula (2).

[0053] ELVDD_R=(R_all) / n-sensor_R……Formula (2) Wherein, ELVDD_R is the impedance value of the voltage routing impedance; R_all represents the total impedance between the voltage routing impedance ELVDD_R and the sensor routing impedance sensor_R; and n represents the number of paths of the voltage routing path.

[0054] Further, in some feasible embodiments, referring to Figure 5The pixel structure module 30 includes a second thin film transistor T2, a third thin film transistor T3, a fourth thin film transistor T4, a capacitor C1 and a light emitting diode D1; the gate of the second thin film transistor T2 is electrically connected to a preset first signal terminal, the first channel terminal of the second thin film transistor T2 is electrically connected to a data line, the second channel terminal of the second thin film transistor T2 is electrically connected to the gate of the third thin film transistor T3, and the first end of the capacitor C1 is arranged between the second channel terminal of the second thin film transistor T2 and the gate of the third thin film transistor T3; the first channel terminal of the third thin film transistor T3 is electrically connected to the power supply terminal, the second end of the capacitor C1 is arranged between the first channel terminal of the third thin film transistor T3 and the power supply terminal, the second channel terminal of the third thin film transistor T3 is electrically connected to the anode of the light emitting diode D1, and the cathode of the light emitting diode D1 is electrically connected to the negative power supply terminal; the gate of the fourth thin film transistor T4 is electrically connected to a preset second signal terminal, the first channel terminal of the fourth thin film transistor T4 is arranged between the second channel terminal of the third thin film transistor T3 and the anode of the light emitting diode D1, and the second channel terminal of the fourth thin film transistor T4 is electrically connected to the sensing trace Ls.

[0055] In this embodiment, the second thin film transistor T2 can be understood as a data control TFT, which is responsible for the charging and discharging of the capacitor C1; the third thin film transistor T3 can be understood as a drive control TFT, which is responsible for controlling the current reaching the light emitting diode D1; the fourth thin film transistor T4 can be understood as a sensing TFT, which is used to detect the current flowing through the third thin film transistor T3, or the anode potential of the light emitting diode D1, so as to calculate the threshold voltage of the third thin film transistor T3.

[0056] It should be noted that the light emitting diode D1 can be understood as an OLED device.

[0057] In a specific embodiment, the display driver module 10 calculates the compensation voltage of the pixel structure module 30; and then connects the compensation voltage to the display driver module 10 electrically connected to the Figure 5 After the data line Ld is connected, the second thin film transistor T2 is turned on under the driving of the capacitor C1 charging signal output from the preset first signal terminal, and the compensation voltage is discharged to the power supply access point of the pixel structure module 30 via the capacitor C1, thereby compensating the ELVDD voltage drop of the pixel structure module 30, so that the pixel power supply voltage received by each pixel structure module 30 distributed in the array is kept consistent. Thereby significantly improving the brightness uniformity of the display panel.

[0058] In summary, the voltage detection display circuit set in the present application is applied to the OLED display screen, and the voltage routing impedance between the ELVDD output point and each sub-pixel (i.e., the pixel structure module 30) can be confirmed through the impedance measurement module 20; next, the impedance value of the voltage routing impedance is stored through the storage component, and then converted into the required compensation voltage based on the normal display current required for the normal display of each sub-pixel and the voltage routing impedance of the sub-pixel and superimposed on the data line to compensate for the ELVDD voltage drop of each sub-pixel, so that the compensation voltage can be distributed to the points, and each sub-pixel can be compensated, so that the display brightness of each sub-pixel is kept consistent, thereby significantly improving the brightness uniformity of the OLED display screen.

[0059] Furthermore, based on the first embodiment of the voltage detection and display circuit of the present application, a second embodiment of a driving method of the voltage detection and display circuit of the present application is proposed.

[0060] The driving method of the voltage detection display circuit of the present application is applied to any of the above-mentioned display circuits. The driving method of the voltage detection display circuit of the present application is executed by a terminal device that compensates the voltage routing impedance of each pixel point of the display panel. The driving method of the voltage detection display circuit of the present application includes the following implementation steps S10 to S20.

[0061] Step S10: When the display driving module 10 provides a pixel power supply voltage to the radial pixel structure module 30 through the voltage routing line from the power supply end to the power supply access point, the impedance measurement module 20 determines the voltage routing impedance of the pixel structure module 30 according to a preset voltage detection signal and the pixel power supply voltage, and transmits the voltage routing impedance to the sensing routing Ls through the impedance measurement module 20.

[0062] In the present embodiment, when the display driving module 10 provides the pixel power supply voltage to the radial pixel structure module 30 via the voltage routing line from the power supply end to the power supply access point, the voltage routing impedance when the pixel power supply voltage is output via the voltage routing path from the power supply end to the power supply access point is determined according to the response of the impedance measurement module 20 to the preset voltage detection signal, and then the voltage routing impedance is transmitted to the display driving module 10 through the sensing routing Ls, thereby realizing the real-time and accurate monitoring of the voltage routing impedance by the display driving module 10, providing reliable data support for the subsequent compensation of the pixel power supply voltage, thereby greatly improving the brightness uniformity of the display panel.

[0063] Step S20: The voltage routing impedance sent by the impedance measurement module 20 via the sensing routing Ls is obtained through the display driving module 10, and a compensation voltage is determined according to the normal display current of the pixel structure module 30 and the voltage routing impedance. The compensation voltage is superimposed on the pixel power supply voltage and then connected to the power supply access point so that the pixel structure module 30 can display normally.

[0064] In this embodiment, the sensing line Ls is electrically connected to the impedance detection end of the display driving module 10. After the display driving module 10 is connected to the voltage line impedance sent by the impedance measurement module 20 via the sensing line Ls, the compensation voltage can be accurately obtained according to the voltage line impedance and the normal display current of the pixel structure module 30. The compensation voltage is then superimposed on the pixel power supply voltage and then connected to the power supply access point of the pixel structure module 30, ensuring that each pixel structure module 30 distributed in the array can obtain a voltage that just meets its normal display requirements, that is, the pixel power supply voltage received by each pixel structure module 30 distributed in the array is consistent. This significantly improves the brightness uniformity of the display panel.

[0065] Furthermore, in some other feasible embodiments, the above step S20: obtaining, by the display driving module 10, the voltage line impedance sent by the impedance measuring module 20 via the sensing line Ls, may also include the following implementation steps S201 to S202.

[0066] Step S201: accessing the actual routing impedance output by the sensing routing Ls through the display driving module 10, and determining the sensing routing Ls impedance corresponding to the sensing routing Ls and the number of paths of the voltage routing path.

[0067] In this embodiment, when the display driver module 10 is connected to the actual routing impedance output by the sensing routing Ls, the sensing routing Ls impedance corresponding to the sensing routing Ls and the number of paths of the voltage routing path are simultaneously determined, thereby providing accurate data support for the subsequent calculation of the impedance value of the voltage routing impedance, so that the display driver module 10 can fully understand the impedance status of the voltage routing path, providing strong support for subsequent voltage compensation and adjustment.

[0068] Step S202 : determining an impedance difference between the actual routing impedance and the sensing routing Ls impedance, and using the ratio data between the impedance difference and the number of paths as the voltage routing impedance sent by the impedance measurement module 20 .

[0069] In this embodiment, the display driving module 10 determines the impedance difference between the actual routing impedance and the sensing routing Ls impedance, which can accurately reflect the impedance change or loss on the voltage routing path; next, the impedance difference is proportionally calculated with the number of voltage routing paths to obtain a proportional data that can accurately reflect the voltage impedance characteristics in the pixel structure module 30, and this proportional data is used as the voltage routing impedance sent by the impedance measurement module 20, which provides a reliable basis for subsequent precise voltage compensation, can ensure the accuracy and effectiveness of voltage compensation, and thus significantly improve the brightness uniformity of OLED products.

[0070] In a specific embodiment, refer to Figure 8 , Figure 8 This is a schematic diagram of the voltage trace impedance calculation involved in the driving method of the voltage detection display circuit of the present application. For example, the number of paths n from DDIC_ELVDD to the test point T is generally 2. This standard is continuous independent channels + 1, that is, the current can be provided by this path alone, such as Figure 8 The number of paths n shown is 3. When testing R_all, it is necessary to disconnect the redundant paths and keep only one path, such as Figure 4 (b) Figure 4 (c) shows the voltage routing path. At this time, the preset voltage detection signal output is high level. Figure 5 The first thin film transistor T1 is in the on state; the preset second signal terminal outputs a signal X2 which is at a low level. Figure 5 The fourth thin film transistor T4 is in the off state, that is, Figure 6 The timing control signal output by the timing control unit 104 is low level, thereby controlling the sensor line Ls to enter the ELVDD impedance detection stage; at this time, DDIC tests R_all minus Sensor_R and divides it by n, which is the voltage line impedance ELVDD_R, and stores this voltage line impedance ELVDD_R in DRAM; next, when displaying normally, it is confirmed that the normal display current required by the pixel structure module 30 is , so the compensation voltage can be determined as = *ELVDD_R, that is, the normal display current required by the pixel structure module 30 is Figure 5 The pressure difference from point G to point T is shown When the voltage at point T drops -When the ELVDD voltage drops, the data line connected to the G point potential is connected to the compensation voltage boost , so that the pixel power supply voltage received by each pixel structure module 30 distributed in the array remains consistent. This significantly improves the brightness uniformity of the display panel.

[0071] In addition, the present application also provides a display panel, which includes any one of the voltage detection and display circuits described above.

[0072] In addition, the present application also provides a display device. Fig. 9 , Fig. 9 The structure diagram of the display device involved in the embodiment of the present application is shown in FIG. The display device in the embodiment of the present application may be a device for locally running the display circuit repair method.

[0073] like Fig. 9 As shown, the display device of the embodiment of the present application may include: the above-mentioned display panel; or, a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a Wi-Fi interface).

[0074] The memory 1005 is arranged on the display device body, and a program is stored in the memory 1005, and the program implements the corresponding operation when it is executed by the processor 1001. The memory 1005 is also used to store parameters for use by the display device. The memory 1005 can be a high-speed RAM memory, or a stable memory (non-volatile memory), such as a disk memory. The memory 1005 can also be a storage device independent of the aforementioned processor 1001.

[0075] Those skilled in the art will understand that Fig. 9 The display device structure shown in the figure does not constitute a limitation on the display device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0076] like Fig. 9 As shown, the memory 1005 as a storage medium may include an operating system, a network communication module, a user interface module, and a repair program for a display circuit of a display device.

[0077] exist Fig. 9 In the display device shown, the processor 1001 can be used to call a repair program for a display circuit of the display device stored in the memory 1005 and execute the steps of the display screen control method as described above.

[0078] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0079] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium such as ROM / RAM, a magnetic disk, or an optical disk as described above, and includes a number of instructions for enabling a display device (which can be a mobile phone, a computer, a server, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0081] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A voltage detection and display circuit, characterized in that: The voltage detection display circuit includes a display driving module, an array-distributed pixel structure module, and an impedance measurement module and a sensing wiring electrically connected to the pixel structure module; The power supply access point of the pixel structure module is electrically connected to the power supply end of the display driving module and the signal access end of the impedance measurement module respectively, and the signal output end of the impedance measurement module is electrically connected to the impedance detection end of the display driving module through the sensing wiring; The impedance measurement module is configured to determine the voltage routing impedance of the pixel structure module according to a preset voltage detection signal and the pixel power voltage when the display driving module radially provides the pixel power voltage to the pixel structure module through the voltage routing line from the power supply end to the power supply access point, and transmit the voltage routing impedance to the sensing routing; The display driving module is configured to obtain the voltage routing impedance sent by the impedance measurement module via the sensing routing, and determine a compensation voltage based on a normal display current of the pixel structure module and the voltage routing impedance, and superimpose the compensation voltage on the pixel power supply voltage and then connect it to the power supply access point so that the pixel structure module can display normally.

2. The voltage detection and display circuit according to claim 1, wherein: The impedance measurement module includes a first thin film transistor and a voltage detection signal terminal; The gate of the first thin film transistor is electrically connected to the voltage detection signal terminal; The first channel end of the first thin film transistor constitutes a signal access end of the impedance measurement module and is electrically connected to a power supply access end of the pixel structure module; The second channel end of the first thin film transistor constitutes a signal output end of the impedance measurement module and is electrically connected to the sensing trace.

3. The voltage detection and display circuit according to claim 1, wherein: The display driving module includes a detection switching unit, an impedance detection unit, a sensing unit and a timing control unit; The sensing end of the detection switching unit is electrically connected to the sensing unit, the detection end of the detection switching unit is electrically connected to the impedance detection unit, and the control end of the detection switching unit is electrically connected to the timing control unit; The signal acquisition end of the detection switching unit constitutes the impedance detection end of the display driving module and is electrically connected to the sensing wiring.

4. The voltage detection and display circuit as claimed in claim 3, characterized in that: The detection switching unit includes an N-type MOS tube and a P-type MOS tube; The gate of the N-type MOS tube is electrically connected to the gate of the P-type MOS tube, and the connection node where the gate of the N-type MOS tube is electrically connected to the gate of the P-type MOS tube constitutes the control end of the detection switching unit and is electrically connected to the timing control unit; The first channel end of the N-type MOS tube constitutes the sensing end of the detection switching unit and is electrically connected to the sensing unit, and the first channel end of the P-type MOS tube constitutes the detection end of the detection switching unit and is electrically connected to the impedance detection unit; The second passage end of the N-type MOS tube is electrically connected to the second passage end of the P-type MOS tube, and the connection intersection where the second passage end of the N-type MOS tube is electrically connected to the second passage end of the P-type MOS tube constitutes the signal collection end of the detection switching unit and is electrically connected to the sensing wiring.

5. The voltage detection and display circuit as claimed in claim 3, characterized in that: The impedance detection unit includes an impedance test component and a storage component, and the impedance test component is electrically connected to the storage component and the detection end of the detection switching unit respectively.

6. The voltage detection and display circuit as claimed in claim 1, characterized in that: The pixel structure module includes a second thin film transistor, a third thin film transistor, a fourth thin film transistor, a capacitor and a light emitting diode; The gate of the second thin film transistor is electrically connected to a preset first signal terminal, the first channel terminal of the second thin film transistor is electrically connected to a data line, the second channel terminal of the second thin film transistor is electrically connected to the gate of the third thin film transistor, and the first terminal of the capacitor is arranged between the second channel terminal of the second thin film transistor and the gate of the third thin film transistor; The first channel end of the third thin film transistor is electrically connected to the power supply end, the second end of the capacitor is arranged between the first channel end of the third thin film transistor and the power supply end, the second channel end of the third thin film transistor is electrically connected to the anode of the light emitting diode, and the cathode of the light emitting diode is electrically connected to the negative power supply end; The gate of the fourth thin film transistor is electrically connected to a preset second signal terminal, the first channel terminal of the fourth thin film transistor is arranged between the second channel terminal of the third thin film transistor and the anode of the light emitting diode, and the second channel terminal of the fourth thin film transistor is electrically connected to the sensing trace.

7. A driving method for a voltage detection and display circuit, characterized in that: The driving method of the voltage detection and display circuit is applied to the voltage detection and display circuit according to any one of claims 1 to 6, and the driving method of the voltage detection and display circuit comprises: When the display driving module provides a pixel power supply voltage to the pixel structure module through a voltage routing line from a power supply end to a power supply access point, the voltage routing impedance of the pixel structure module is determined according to a preset voltage detection signal and the pixel power supply voltage by an impedance measurement module, and the voltage routing impedance is transmitted to a sensing routing by the impedance measurement module; The voltage routing impedance sent by the impedance measurement module via the sensing routing is obtained through the display driving module, and a compensation voltage is determined based on the normal display current of the pixel structure module and the voltage routing impedance. The compensation voltage is superimposed on the pixel power supply voltage and then connected to the power supply access point to allow the pixel structure module to display normally.

8. The driving method of the voltage detection display circuit as claimed in claim 7, characterized in that: The step of obtaining, by the display driving module, the voltage line impedance sent by the impedance measuring module via the sensing line comprises: Accessing the actual routing impedance output by the sensing routing through the display driving module, and determining the sensing routing impedance corresponding to the sensing routing and the number of paths of the voltage routing path; An impedance difference between the actual routing impedance and the sensing routing impedance is determined, and ratio data between the impedance difference and the number of paths is used as the voltage routing impedance sent by the impedance measurement module.

9. A display panel, characterized in that: The display panel includes the voltage detection and display circuit according to any one of claims 1 to 6.

10. A display device, characterized in that: The display device comprises the display panel according to claim 9; or, The display device includes a processor, a memory, and a driver program for a voltage detection display circuit stored in the memory and executable by the processor, wherein when the driver program for the voltage detection display circuit is executed by the processor, the steps of the driving method for the voltage detection display circuit as described in any one of claims 7 to 8 are implemented.

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