Voltage compensation circuit and display

Abstract

The present application relates to a voltage compensation circuit and a display, wherein the voltage compensation circuit includes: an electroluminescent device; a driving unit for driving the electroluminescent device; a light emission duration control unit, which is respectively connected to the driving unit and the electroluminescent device and is used to control the light emission time of the electroluminescent device; and a compensation unit, which is respectively connected to the driving unit and the light emission duration control unit and is used to provide a compensation voltage for the voltage compensation circuit. The voltage compensation circuit in the present application compensates for the decreased voltage value, thereby improving the brightness uniformity of the display and improving the picture quality.

Description

Technical Field

[0001] The present application relates to the technical field of electronic circuits, and in particular to a voltage compensation circuit and a display. Background Art

[0002] Electroluminescence (EL) devices, including OLED, LED, etc., have been widely used in the production of display products in recent years. Compared with traditional displays (CRT, LCD, etc.), their application shows better optical properties, lower power consumption and better product form plasticity. Due to the current-driven properties of electroluminescent devices, when used to make displays, with typical active matrix (AM) or passive matrix (PM) driving methods, the IR-drop problem will inevitably occur due to the large electrical load caused by the current passing through the circuit and EL devices. This problem causes the voltage value to drop, deviating from the supply voltage value of the original voltage source, and this problem directly causes the driving voltage drop of the EL device, which affects the current drop flowing through the EL device, and finally reduces the brightness, which is reflected in the decrease of the brightness uniformity of the panel, which greatly impacts the picture quality of the display.

[0003] Therefore, the prior art needs to be improved. Summary of the invention

[0004] The technical problem to be solved by the present application is to provide a voltage compensation circuit to compensate for the decreased voltage value, thereby improving the brightness uniformity of the display and improving the picture quality.

[0005] In a first aspect, an embodiment of the present application provides a voltage compensation circuit, the circuit comprising:

[0006] Electroluminescent devices;

[0007] A driving unit, used for driving the electroluminescent device;

[0008] A light-emitting duration control unit, connected to the driving unit and the electroluminescent device respectively, and used to control the light-emitting time of the electroluminescent device;

[0009] A compensation unit is connected to the driving unit and the light-emitting duration control unit respectively, and is used to provide a compensation voltage for the voltage compensation circuit.

[0010] Optionally, a fixed current is input to the compensation unit through an external circuit, the compensation unit receives the fixed current and outputs a compensation voltage through the driving unit, the driving unit receives the compensation voltage and outputs a stable current through the luminous duration control unit to the electro-luminescent device to drive the electro-luminescent device.

[0011] Optionally, a first reference voltage is input to the compensation unit, and the compensation unit adjusts the magnitude of the compensation voltage according to the first reference voltage.

[0012] Optionally, a second reference voltage is input to the compensation unit so that the driving unit obtains an adjustable cross-voltage and outputs a stable current to the electroluminescent device through the light-emitting duration control unit to drive the electroluminescent device.

[0013] Optionally, the compensation unit includes:

[0014] a second transistor, a third transistor, a fourth transistor, a fifth transistor and a capacitor;

[0015] The gate of the fourth transistor is connected to the first signal control terminal, the source of the fourth transistor is connected to the first reference voltage, and the drain of the fourth transistor is connected to the first end of the capacitor; the second end of the capacitor is connected to the source of the third transistor, the drain of the third transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the fixed current input terminal; the first signal control terminal is also connected to the gate of the second transistor and the gate of the third transistor respectively;

[0016] The source of the fifth transistor is connected to the second reference voltage, the drain of the fifth transistor is connected to the first end of the capacitor, and the gate of the fifth transistor is connected to the second signal control end (the gate of the fifth transistor receives the second control signal).

[0017] Optionally, the driving unit comprises:

[0018] a first transistor;

[0019] The gate of the first transistor is connected to the second end of the capacitor, the source of the first transistor is connected to the power supply end, and the drain of the first transistor is connected to the source of the first switch transistor.

[0020] Optionally, the lighting duration control unit includes:

[0021] a first switching transistor and a second switching transistor;

[0022] The source of the first switch transistor is connected to the drain of the first transistor, the drain of the first switch transistor is connected to the source of the second switch transistor, and the gate of the first switch transistor is connected to the second signal control terminal; the source of the second switch transistor is connected to the drain of the first switch transistor, the drain of the second switch transistor is connected to the anode of the electroluminescent device, and the gate of the second switch transistor is connected to the third signal control terminal; the cathode of the electroluminescent device is grounded.

[0023] Optionally, the first signal control terminal is used to provide a first control signal, and the first control signal is used to control the on and off of the second transistor, the third transistor and the fourth transistor.

[0024] Optionally, the second control terminal provides a second control signal for controlling the on and off of the fifth transistor and the first switch transistor.

[0025] Optionally, the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the first switch transistor and the second switch transistor are all P-type transistors.

[0026] Optionally, the compensation unit includes:

[0027] a second transistor, a third transistor, a fourth transistor, a fifth transistor and a capacitor;

[0028] The gate of the fourth transistor is connected to the first signal control terminal, the source of the fourth transistor is connected to the first reference voltage, and the drain of the fourth transistor is connected to the first end of the capacitor; the second end of the capacitor is connected to the source of the third transistor, the drain of the third transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the fixed current input terminal; the first signal control terminal is also connected to the gate of the second transistor and the gate of the third transistor respectively;

[0029] A source of the fifth transistor is connected to a second reference voltage, and a drain of the fifth transistor is connected to a first end of the capacitor.

[0030] Optionally, the driving unit comprises:

[0031] a first transistor;

[0032] The gate of the first transistor is connected to the second end of the capacitor, the source of the first transistor is connected to the drain of the first switch transistor, and the drain of the first transistor is grounded.

[0033] Optionally, the lighting duration control unit includes:

[0034] a first switching transistor and a second switching transistor;

[0035] The source of the first switch transistor is connected to the drain of the second switch transistor, the drain of the first switch transistor is connected to the source of the first transistor, and the gate of the first switch transistor is connected to the second signal control terminal; the drain of the second switch transistor is connected to the source of the first switch transistor, the source of the second switch transistor is connected to the cathode of the electroluminescent device, and the gate of the second switch transistor is connected to the third signal control terminal; the anode of the electroluminescent device is connected to the power supply terminal.

[0036] Optionally, the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor, the first switch transistor and the second switch transistor are all N-type transistors.

[0037] In a second aspect, an embodiment of the present application provides a display, including: the display includes the above-mentioned voltage compensation circuit.

[0038] Compared with the prior art, the embodiments of the present application have the following advantages:

[0039] According to the voltage compensation circuit provided in the embodiment of the present application, it includes an electroluminescent device; a driving unit for driving the electroluminescent device; a light-emitting duration control unit connected to the driving unit and the electroluminescent device respectively, for controlling the light-emitting time of the electroluminescent device; a compensation unit connected to the driving unit and the light-emitting duration control unit respectively, for providing a compensation voltage for the voltage compensation circuit. The voltage compensation circuit in the present application compensates for the decreased voltage value, thereby improving the brightness uniformity of the display and improving the picture quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] 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, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a schematic diagram of the structure of a voltage compensation circuit in an embodiment of the present application;

[0042] Figure 2 A schematic diagram of a voltage compensation circuit in a panel with n rows and m columns in an embodiment of the present application;

[0043] Figure 3 This is a schematic diagram of the structure of a p-type voltage compensation circuit in an embodiment of the present application;

[0044] Figure 4 A schematic diagram of a signal waveform of a p-type voltage compensation circuit in an embodiment of the present application;

[0045] Figure 5 This is a schematic diagram of the structure of the first stage voltage compensation circuit of the p-type voltage compensation circuit in an embodiment of the present application;

[0046] Figure 6 This is a schematic diagram of the first stage signal waveform of the p-type voltage compensation circuit in the embodiment of the present application;

[0047] Figure 7 This is a schematic diagram of the structure of the second stage voltage compensation circuit of the p-type voltage compensation circuit in an embodiment of the present application;

[0048] Figure 8 This is a schematic diagram of the second stage signal waveform of the p-type voltage compensation circuit in the embodiment of the present application;

[0049] Fig. 9 Schematic diagram of the structure of an n-type voltage compensation circuit in an embodiment of the present application. DETAILED DESCRIPTION

[0050] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings 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.

[0051] After research, the inventors found that the existing circuit design, under the AM or PM driving method of a typical EL display, has an IR-drop (voltage drop) problem due to its nature. This problem causes a drop in voltage value, deviating from the supply voltage value of the original voltage source. This problem directly causes the driving cross-voltage of the EL device to drop, which affects the drop in current flowing through the EL device, and ultimately reduces the brightness, which is reflected in the decrease in the brightness uniformity of the panel, greatly impacting the picture quality of the display.

[0052] In order to solve the above problems, in an embodiment of the present application, a fixed current input terminal is used to adjust the current signal, and a 7T1C (7 transistors and 1 capacitor) pixel circuit architecture is combined to compensate for the decreased voltage value, thereby realizing an external compensation circuit system (External Compensation Circuit and System), thereby improving the brightness uniformity of the display and improving the picture quality.

[0053] Various non-limiting implementations of the present application are described in detail below in conjunction with the accompanying drawings.

[0054] The present application embodiment provides a voltage compensation circuit, such as Figure 1 As shown, the voltage compensation circuit includes:

[0055] Electroluminescent device (EL device) 10;

[0056] A driving unit 12, used for driving the electroluminescent device 10;

[0057] A light-emitting duration control unit 14, connected to the driving unit 12 and the electroluminescent device 10, respectively, for controlling the light-emitting time of the electroluminescent device;

[0058] The compensation unit 16 is connected to the driving unit 12 and the light-emitting duration control unit 14 respectively, and is used to provide a compensation voltage for the voltage compensation circuit.

[0059] The present invention inputs a fixed current to the compensation unit 16 through an external circuit, the compensation unit 16 receives the fixed current and outputs a compensation voltage through the driving unit 12, the driving unit 12 receives the compensation voltage and outputs a stable current through the luminous duration control unit 14 to the electroluminescent device 10 to drive the electroluminescent device 10, and voltage compensation is performed to compensate for the voltage drop problem caused by the electrical load, thereby improving the brightness uniformity of the display and improving the picture display quality.

[0060] Furthermore, please combine Figure 3 By inputting a first reference voltage VREF1 to the compensation unit 16, the compensation unit 16 can adjust the magnitude of the compensation voltage according to the first reference voltage VREF1. Furthermore, by inputting a second reference voltage VREF2 to the compensation unit 16, the driving unit 12 obtains an adjustable cross-voltage, and outputs a stable current to the electroluminescent device 10 after passing through the light-emitting duration control unit 14 to drive the electroluminescent device 10.

[0061] like Figure 2As shown, the circuit architecture is established on the nth row and mth column in the panel, and the row control signals are S1 and EM, which are used for the functional operation of the pixel circuit, and the column control signal in the vertical direction is SEL, which is a PWM function signal used to control the light-emitting time of the EL device. The key IS signal provides an adjustable constant current signal, which is connected to an external circuit (usually connected to a DDIC / display driver chip) to realize an external compensation circuit system to improve the voltage drop problem caused by IR-drop.

[0062] In the embodiment of the present application, there are two types of voltage compensation circuits: p-type and n-type. The voltage compensation circuit includes 7 TFT or MOS active devices including 1 capacitor device, 3 circuit control signals, and IS[m] is an adjustable constant current signal. The difference between the n-type circuit architecture and the p-type is the difference in the connection position between the EL device and other devices (including active and passive devices).

[0063] If the voltage compensation circuit is of p-type, the transistors in the circuit are p-type transistors. Figure 3 As shown, the connection method of the voltage compensation circuit is as follows:

[0064] The compensation unit 16 comprises:

[0065] A second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5 and a capacitor C;

[0066] The gate of the fourth transistor T4 is connected to the first signal control terminal (the gate of the fourth transistor receives the first control signal S1), the source of the fourth transistor T4 is connected to the first reference voltage VREF1, and the drain of the fourth transistor T4 is connected to the first end of the capacitor C; the second end of the capacitor C is connected to the source of the third transistor T3, the drain of the third transistor T3 is connected to the source of the second transistor T2, and the drain of the second transistor T2 is connected to the fixed current input terminal (the fixed current input terminal inputs an adjustable constant current signal IS); the first signal control terminal is also connected to the gate of the second transistor T2 and the gate of the third transistor T3 respectively;

[0067] The source of the fifth transistor T5 is connected to the second reference voltage VREF2, the drain of the fifth transistor T5 is connected to the first end of the capacitor C, and the gate of the fifth transistor T5 is connected to the second signal control end (the gate of the fifth transistor receives the second control signal EM).

[0068] The driving unit 12 comprises:

[0069] A first transistor T1;

[0070] The gate of the first transistor T1 is connected to the second end of the capacitor C, the source of the first transistor T1 is connected to the power supply terminal VDD, and the drain of the first transistor T1 is connected to the source of the first switch transistor T6.

[0071] The light-emitting duration control unit 14 includes:

[0072] A first switching transistor T6 and a second switching transistor T7;

[0073] The source of the first switch transistor T6 is connected to the drain of the first transistor T1, the drain of the first switch transistor T6 is connected to the source of the second switch transistor T7, and the gate of the first switch transistor T6 is connected to the second signal control terminal (the gate of the first switch transistor receives the second control signal EM); the source of the second switch transistor T7 is connected to the drain of the first switch transistor T6, the drain of the second switch transistor T7 is connected to the anode of the electroluminescent device EL, and the gate of the second switch transistor is connected to the third signal control terminal (the gate of the second switch transistor receives the third control signal SEL); the cathode of the electroluminescent device EL is grounded VSS.

[0074] Specifically, the first transistor T1 , the second transistor T2 , the third transistor T3 , the fourth transistor T4 , the fifth transistor T5 , the first switch transistor T6 and the second switch transistor T7 are all P-type transistors.

[0075] In order to better understand the present invention, a p-type voltage compensation circuit is taken as an example to explain its working process in combination with the timing action. Figure 4 As shown, Figure 4 Schematic diagram of signal waveforms of a p-type voltage compensation circuit, wherein the first control signal S1[n] (low level is effective) is used to control the on / off of the second transistor T2, the third transistor T3 and the fourth transistor T4, the second control signal EM[n] (low level is effective) is used to control the on / off of the fifth transistor T5 and the sixth switch transistor T6, and the third control signal SEL[m] (normally closed) is a PWM function signal used to control the light-emitting time of the EL device. Specifically, the timing action includes the following two stages:

[0076] Phase 1: Please combine Figure 5 and Figure 6As shown, in the first stage, i.e., at time T1, since the first control signal S1 is at a low level (low level is effective), the first transistor T1, the second transistor T2, the third transistor T3 and the fourth transistor T4 are in an open state, and since the second control signal EM is at a high level, the fifth transistor T5 and the sixth switch transistor T6 are in an open state ( Figure 5 The "×" in the figure indicates the off state). The present invention is connected to the external circuit through IS[m] (the first control signal) to supply an adjustable fixed current source to determine the Vgs voltage value of the first transistor T1 to complete the compensation function. Since the power supply terminal VDD participates in this current path, this voltage value achieves the purpose of compensating the voltage drop caused by IR-drop. More specifically, the relationship between the nodes can be expressed by the following formula:

[0077] Va=VDD-Vth-VIS:Compensation voltage is written, VIS is determined by the current size of IS[m].

[0078] Vb=VREF1: Pulled to a reference fixed potential, which can be used to adjust the current output size.

[0079] The second stage: Figure 7 and Figure 8 As shown, in the second stage, that is, at time T2, since the first control signal S1 is at a high level, the first transistor T1, the second transistor T2, the third transistor T3 and the fourth transistor T4 are in a disconnected state, and since the second control signal EM is at a low level, the fifth transistor T5 and the sixth switch transistor T6 are in an open state. The present invention writes the second reference voltage VREF2 and couples the first transistor T1 with the capacitor C to obtain an adjustable cross-voltage, so that the first transistor T1 can output a stable current 6 to achieve the required luminous brightness of the EL device, and the second switch transistor T7 is used as a time controller to control the current passing through the EL device, corresponding to the luminous brightness and grayscale. More specifically, the relationship between the nodes can be expressed by the following formula:

[0080] Va=VDD-Vth-VIS+(VREF2–VREF1), the final output compensation voltage value.

[0081] Vb=VREF2, and the voltage difference between VREF1 and VREF2 is coupled to T1 through C.

[0082] Finally, IEL = kx(VDD – Va – Vth) 2 =kx(VIS+VREF1–VREF2) 2 This formula has no VDD parameter factor, so it is not affected by the VDD voltage drop and completes the compensation current output.

[0083] If the voltage compensation circuit is of n-type, the transistors in the circuit are N-type transistors, that is, the first transistor T1, the second transistor T2, the third transistor T3, the fourth transistor T4, the fifth transistor T5, the first switch transistor T6 and the second switch transistor T7 are all N-type transistors. Fig. 9 As shown, the connection method of the voltage compensation circuit is as follows:

[0084] The compensation unit 16 comprises:

[0085] A second transistor T2, a third transistor T3, a fourth transistor T4, a fifth transistor T5 and a capacitor C;

[0086] The gate of the fourth transistor T4 is connected to the first signal control terminal (the gate of the fourth transistor receives the first control signal S1), the source of the fourth transistor T4 is connected to the first reference voltage VREF1, and the drain of the fourth transistor T4 is connected to the first end of the capacitor C; the second end of the capacitor C is connected to the source of the third transistor T3, the drain of the third transistor T3 is connected to the source of the second transistor T2, and the drain of the second transistor T2 is connected to the fixed current input terminal (the fixed current input terminal inputs an adjustable constant current signal IS); the first signal control terminal is also connected to the gate of the second transistor T2 and the gate of the third transistor T3 respectively;

[0087] The source of the fifth transistor T5 is connected to the second reference voltage VREF2 , and the drain of the fifth transistor T5 is connected to the first end of the capacitor C.

[0088] The driving unit 12 comprises:

[0089] A first transistor T1;

[0090] The gate of the first transistor T1 is connected to the second end of the capacitor C, the source of the first transistor T1 is connected to the drain of the first switch transistor T6, and the drain of the first transistor T1 is grounded.

[0091] The light-emitting duration control unit 14 includes:

[0092] A first switching transistor T6 and a second switching transistor T7;

[0093] The source of the first switch transistor T6 is connected to the drain of the second switch transistor T7, the drain of the first switch transistor T6 is connected to the source of the first transistor T1, and the gate of the first switch transistor T6 is connected to the second signal control terminal (the gate of the first switch transistor receives the second control signal EM); the drain of the second switch transistor T7 is connected to the source of the first switch transistor T6, the source of the second switch transistor T7 is connected to the cathode of the electroluminescent device EL, and the gate of the second switch transistor T7 is connected to the third signal control terminal (the gate of the second switch transistor receives the third control signal SEL); the anode of the electroluminescent device EL is connected to the power supply terminal VDD.

[0094] Based on the typical display driving method and circuit design, a common power supply is used. Except for the pixels at the edge of the panel, the pixels in the display area are powered by direct wiring of the circuit. When the EL device is operated to emit light, a large electrical load is provided, which causes different voltage drops to be generated at the pixels in the display area, which is reflected in a direct decrease in brightness and degradation of brightness uniformity.

[0095] The voltage compensation circuit of the present application utilizes IS[m] to adjust the current signal and combines the 7T1C (7 Transistors and 1 Capacitor) pixel circuit architecture to compensate for the decreased voltage value, thereby realizing an external compensation circuit system (External Compensation Circuit and System), solving the problem of brightness uniformity of the display and improving the picture quality.

[0096] The present application provides a display, which includes the above-mentioned voltage compensation circuit.

[0097] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A voltage compensation circuit, characterized in that: The circuit comprises: Electroluminescent devices; A driving unit, used for driving the electroluminescent device; a light-emission duration control unit, connected to the driving unit and the electroluminescent device respectively, and used to control the light-emission time of the electroluminescent device, wherein the light-emission duration control unit comprises a first switching transistor and a second switching transistor connected in sequence, wherein the gate of the first switching transistor is used to receive a second control signal, and the gate of the second switching transistor is used to receive a third control signal; a compensation unit, connected to the driving unit and the light-emitting duration control unit respectively, and used to provide a compensation voltage for the voltage compensation circuit, specifically, the compensation unit includes a second transistor, a third transistor, a fourth transistor, a fifth transistor and a capacitor, the gates of the second transistor, the third transistor and the fourth transistor are all connected to the same signal control terminal, the third transistor is connected in series with the second transistor and then connected to one end of the capacitor, the other end of the second transistor is also connected to the fixed current input terminal, one end of the fourth transistor is connected to the first reference voltage, one end of the fifth transistor is connected to the second reference voltage, and the other ends of the fourth transistor and the fifth transistor are both connected to the other end of the capacitor; First, turn on the second transistor, the third transistor and the fourth transistor, turn off the fifth transistor and the light-emitting duration control unit, connect the fixed current input terminal to the external circuit, and input the first reference voltage to the fourth transistor. At this time, the voltage at one end of the capacitor connected to the third transistor is VDD-Vth-VIS, wherein VDD is the power supply voltage, Vth is the threshold voltage of the driving unit, VIS is the input voltage of the fixed current input terminal, and the voltage at the other end of the capacitor is the first reference voltage VREF1; secondly, turn off the second transistor, the third transistor and the fourth transistor, turn on the fifth transistor and the light-emitting duration control unit, and input the second reference voltage to the fifth transistor. At this time, the voltage at the other end of the capacitor changes from the first reference voltage VREF1 to the second reference voltage VREF2, and the voltage at one end of the capacitor connected to the third transistor changes to VDD-Vth-VIS+(VREF2-VREF1) through coupling.

2. The voltage compensation circuit according to claim 1, characterized in that: A fixed current is input to the compensation unit through an external circuit, the compensation unit receives the fixed current and outputs a compensation voltage through the driving unit, the driving unit receives the compensation voltage and outputs a stable current through the luminous duration control unit to the electroluminescent device to drive the electroluminescent device.

3. The voltage compensation circuit according to claim 1, characterized in that: A first reference voltage is input to the compensation unit, and the compensation unit adjusts the magnitude of the compensation voltage according to the first reference voltage.

4. The voltage compensation circuit according to claim 2, characterized in that: A second reference voltage is input to the compensation unit so that the driving unit obtains an adjustable cross-voltage, and a stable current is output to the electroluminescent device through the light-emitting duration control unit to drive the electroluminescent device.

5. The voltage compensation circuit according to claim 4, characterized in that: The compensation unit comprises: a second transistor, a third transistor, a fourth transistor, a fifth transistor and a capacitor; The gate of the fourth transistor is connected to the first signal control terminal, the source of the fourth transistor is connected to the first reference voltage, and the drain of the fourth transistor is connected to the first end of the capacitor; the second end of the capacitor is connected to the source of the third transistor, the drain of the third transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the fixed current input terminal; the first signal control terminal is also connected to the gate of the second transistor and the gate of the third transistor respectively; The source of the fifth transistor is connected to the second reference voltage, the drain of the fifth transistor is connected to the first end of the capacitor, and the gate of the fifth transistor is connected to the second signal control end.

6. The voltage compensation circuit according to claim 5, characterized in that: The driving unit comprises: a first transistor; The gate of the first transistor is connected to the second end of the capacitor, the source of the first transistor is connected to the power supply end, and the drain of the first transistor is connected to the source of the first switch transistor.

7. The voltage compensation circuit according to claim 6, characterized in that: The light-emitting duration control unit comprises: a first switching transistor and a second switching transistor; The source of the first switch transistor is connected to the drain of the first transistor, the drain of the first switch transistor is connected to the source of the second switch transistor, and the gate of the first switch transistor is connected to the second signal control terminal; the source of the second switch transistor is connected to the drain of the first switch transistor, the drain of the second switch transistor is connected to the anode of the electroluminescent device, and the gate of the second switch transistor is connected to the third signal control terminal; the cathode of the electroluminescent device is grounded.

8. The voltage compensation circuit according to claim 4, characterized in that: The compensation unit comprises: a second transistor, a third transistor, a fourth transistor, a fifth transistor and a capacitor; The gate of the fourth transistor is connected to the first signal control terminal, the source of the fourth transistor is connected to the first reference voltage, and the drain of the fourth transistor is connected to the first end of the capacitor; the second end of the capacitor is connected to the source of the third transistor, the drain of the third transistor is connected to the source of the second transistor, and the drain of the second transistor is connected to the fixed current input terminal; the first signal control terminal is also connected to the gate of the second transistor and the gate of the third transistor respectively; A source of the fifth transistor is connected to a second reference voltage, and a drain of the fifth transistor is connected to a first end of the capacitor.

9. The voltage compensation circuit according to claim 8, characterized in that: The driving unit comprises: a first transistor; The gate of the first transistor is connected to the second end of the capacitor, the source of the first transistor is connected to the drain of the first switch transistor, and the drain of the first transistor is grounded; The light-emitting duration control unit comprises: a first switching transistor and a second switching transistor; The source of the first switch transistor is connected to the drain of the second switch transistor, the drain of the first switch transistor is connected to the source of the first transistor, and the gate of the first switch transistor is connected to the second signal control terminal; the drain of the second switch transistor is connected to the source of the first switch transistor, the source of the second switch transistor is connected to the cathode of the electroluminescent device, and the gate of the second switch transistor is connected to the third signal control terminal; the anode of the electroluminescent device is connected to the power supply terminal.

10. A display, characterized in that: The display comprises the voltage compensation circuit according to any one of claims 1 to 9.

Images