Driving circuit and driving method of display panel

Abstract

The application discloses a driving circuit and a driving method of a display panel, the display panel comprising a plurality of pixel units arranged in an array, each pixel unit comprising a connected driving transistor and a light emitting element, wherein the driving circuit comprises a temperature detection unit for detecting the temperature of the display panel to obtain a temperature detection signal; and a substrate control unit connected with the substrate of the driving transistor, for adjusting the substrate voltage of the driving transistor according to the temperature detection signal, so as to change the light emitting current of the light emitting element; the driving method comprises detecting the temperature of the display panel to obtain a temperature detection signal; and adjusting the substrate voltage of the driving transistor according to the temperature detection signal, so as to change the light emitting current of the light emitting element.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a driving circuit and driving method for a display panel. Background Technology

[0002] In recent years, OLED (Organic Light-Emitting Diode) displays have gradually become one of the mainstream display devices due to their numerous advantages, such as self-illumination, small thickness, low power consumption, fast response speed, and low manufacturing cost. An OLED display device includes a substrate on which organic light-emitting units composed of pixel circuits, an anode, an organic light-emitting layer, and a cathode are formed. The anode and cathode are led out in the non-light-emitting areas by leads and bonded to integrated circuits or FPCs (Flexible Printed Circuits).

[0003] The light-emitting elements of OLED displays are highly sensitive to temperature; they exhibit different brightness-voltage and current-voltage characteristic curves at different temperatures. Figure 1a and Figure 1b As shown. Figure 1a The brightness-voltage characteristic curves of the light-emitting element at different temperatures are shown. Figure 1b The current-voltage characteristic curves of the light-emitting element at different temperatures are shown. Taking an 8V voltage as an example, at 25℃, the current of the light-emitting element is approximately 25mA, and the luminance is approximately 1500cd / cm². 2 After a certain period of time, the chip temperature rises due to heat generated by hardware power consumption, for example, to 65°C. At this point, although the voltage is still 8V, the current of the light-emitting element is approximately 65mA, and the brightness is approximately 3800 cd / cm². 2 As you can see, in Figure 1a and Figure 1b In the same voltage, as the temperature rises, the current and brightness will increase accordingly. In practical applications, the increase in current and brightness will lead to a further increase in power consumption and temperature, thus creating a positive feedback loop of increased temperature and increased brightness. This will not only reduce the lifespan of the light-emitting element, but also cause users to clearly feel the continuous change in brightness without changing the brightness settings, reducing the comfort of their user experience.

[0004] Traditional display devices such as Figure 2 As shown, Figure 2A partial structural schematic diagram of a prior art display device is shown. The display device includes a display panel 110 and a temperature detection unit 150. The display panel 110 includes a display area 111 and a non-display area. The display area 111 includes, for example, a plurality of pixel units 101 arranged in an array. The temperature detection unit 150 is located, for example, in the non-display area of ​​the display panel 110 and is symmetrically distributed on both sides of the display area 111. It is configured to detect the temperature of the display panel 110 to obtain a temperature detection signal Vfb. Figure 3 It shows Figure 2 A schematic diagram of the structure of the pixel unit 101 is shown. The pixel unit 101 includes a storage capacitor circuit 201, a data writing circuit 202, a driving circuit 203, a light emission duration control circuit 204, and a light emission element 205. The data writing circuit 202 is connected to the storage capacitor circuit 201 and receives the data voltage Vdata. The driving circuit 203 is connected to the storage capacitor circuit 201 and the data writing circuit 202, and receives the driving voltage ELVDD, which is used to drive the light emission element 205 to emit light. The light emission duration control circuit 204 is connected to the driving circuit 203 and controls the light emission duration of the light emission element 205 by turning it on and off. The light emission element 205 is connected to the light emission duration control circuit 204 and receives the common ground voltage ELVSS, and emits light under the drive of the driving circuit 203. In traditional solutions, for example, a temperature detection unit 150 detects the temperature of the display panel 110 and adjusts the data voltage Vdata according to different temperatures. The adjusted data voltage Vdata is then written to the pixel unit 101 through the data writing circuit 202 according to the specified timing for brightness compensation, achieving the function of maintaining stable brightness at different temperatures. However, traditional solutions require a large amount of OTP (One-Time Programmable) memory and corresponding algorithms, resulting in excessive space consumption.

[0005] Therefore, there is an expectation for an improved display panel driving circuit and driving method that can solve the above problems. Summary of the Invention

[0006] In view of the above problems, the purpose of the present invention is to provide a driving circuit and driving method for a display panel, which changes the current driving capability of the driving transistor by changing the substrate voltage of the driving transistor, ensuring that the current flowing through the light-emitting element remains stable, thereby achieving the requirement that the display panel has the same brightness at different temperatures.

[0007] According to one aspect of this application, a driving circuit for a display panel is provided. The display panel includes a plurality of pixel units arranged in an array, each pixel unit including a connected driving transistor and a light-emitting element. The driving circuit includes: a temperature detection unit for detecting the temperature of the display panel to obtain a temperature detection signal; and a substrate control unit connected to the substrate of the driving transistor for adjusting the substrate voltage of the driving transistor according to the temperature detection signal to change the light-emitting current of the light-emitting element.

[0008] Optionally, the driving transistor is a P-channel MOS transistor, and the substrate control unit is configured such that the substrate voltage of the driving transistor increases as the temperature of the display panel increases.

[0009] Optionally, the driving transistor is an N-channel MOS transistor, and the substrate control unit is configured such that the substrate voltage of the driving transistor decreases as the temperature of the display panel increases.

[0010] Optionally, the substrate control unit includes: a compensation voltage calculation module, used to compare the temperature detection signal with a set temperature threshold and calculate a corresponding compensation voltage based on the comparison result; and a voltage conversion module, used to convert the compensation voltage to generate an adjustment signal and adjust the substrate voltage of the driving transistor according to the adjustment signal.

[0011] Optionally, the adjustment signal is the sum of the driving voltage and the preset voltage, wherein the preset voltage is positively correlated with the temperature.

[0012] Optionally, the voltage conversion module is implemented using a low-dropout linear regulator.

[0013] According to another aspect of this application, a driving method for a display panel is provided. The display panel includes a plurality of pixel units arranged in an array, each pixel unit including a connected driving transistor and a light-emitting element. The driving method includes: detecting the temperature of the display panel to obtain a temperature detection signal; and adjusting the substrate voltage of the driving transistor according to the temperature detection signal to change the light-emitting current of the light-emitting element.

[0014] Optionally, the driving transistor is a P-channel MOS transistor, and the step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: increasing the substrate voltage of the driving transistor as the temperature of the display panel increases.

[0015] Optionally, the driving transistor is an N-channel MOS transistor, and the step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: making the substrate voltage of the driving transistor decrease as the temperature of the display panel increases.

[0016] Optionally, the step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: comparing the temperature detection signal with a set temperature threshold, calculating a corresponding compensation voltage based on the comparison result; performing voltage conversion on the compensation voltage to generate an adjustment signal, and adjusting the substrate voltage of the driving transistor according to the adjustment signal.

[0017] Optionally, the adjustment signal is the sum of the driving voltage and the preset voltage, wherein the preset voltage is positively correlated with the temperature.

[0018] Optionally, the step of voltage conversion of the compensation voltage includes: voltage conversion of the compensation voltage using a low-dropout linear regulator.

[0019] The display panel driving circuit and driving method provided in this application involve a substrate control unit changing the substrate voltage of the driving transistor in the pixel unit according to the temperature detection signal provided by the temperature detection unit, thereby changing the current driving capability of the driving transistor. When the display panel temperature rises, the current driving capability of the driving transistor is reduced to decrease the light emission current, thereby ensuring that the brightness of the display panel remains stable when the temperature changes.

[0020] Optionally, the driving circuit and driving method of the display panel provided in this application change the substrate voltage of the driving transistor by providing different adjustment signals through the substrate control unit, thereby changing its current driving capability. When the temperature of the display panel increases (e.g., above 25°C) and the light-emitting current flowing through the light-emitting element increases, in order to reduce the light-emitting current flowing through the light-emitting element, the substrate control unit increases the adjustment signal it provides to the driving transistor to increase the substrate voltage of the driving transistor and reduce its current driving capability, thereby keeping the light-emitting current flowing through the light-emitting element stable and ensuring that the brightness of the display area remains stable even when the temperature rises. Attached Figure Description

[0021] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0022] Figure 1a The brightness-voltage characteristic curves of the light-emitting element at different temperatures are shown.

[0023] Figure 1b The current-voltage characteristic curves of the light-emitting element at different temperatures are shown.

[0024] Figure 2 A partial structural schematic diagram of a prior art display device is shown.

[0025] Figure 3It shows Figure 2 A schematic diagram of the structure of a mid-pixel unit.

[0026] Figure 4 A schematic diagram of a display device including the driving circuitry of an embodiment of this application is shown.

[0027] Figure 5a A schematic diagram of the structure of a pixel unit according to an embodiment of this application is shown.

[0028] Figure 5b It shows Figure 5a Equivalent circuit diagram of the middle pixel unit.

[0029] Figure 6 It shows Figure 4 A schematic diagram of the substrate control unit module.

[0030] Figure 7 A driving method for a display panel according to an embodiment of this application is shown.

[0031] Figure 8 The current-voltage characteristic curves of the driving transistor in the embodiments of this application are shown.

[0032] Figure 9 The brightness-voltage characteristic curves of the light-emitting element at different temperatures in the embodiments of this application are shown.

[0033] Figure 10 A schematic diagram of the structure of a pixel unit according to another embodiment of this application is shown.

[0034] Figure 11 A schematic diagram of the structure of a pixel unit according to another embodiment of this application is shown.

[0035] Figure 12 A schematic diagram of the structure of a pixel unit according to another embodiment of this application is shown. Detailed Implementation

[0036] Various embodiments of the invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements or modules are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0037] It should be understood that, in the following description, "circuit" may include single or combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by the programmable circuit. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it may be directly coupled or connected to the other element, or there may be intermediate elements; the connection between elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them.

[0038] Furthermore, certain terms are used in this patent specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This patent specification and claims do not distinguish components based on differences in name, but rather on differences in function.

[0039] In this application, a transistor may include one selected from bipolar transistors or field-effect transistors. The first and second terminals of the transistor are respectively a high-potential terminal and a low-potential terminal on the current path. A control terminal is used to receive a control signal to control the transistor's on and off states. A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) includes a first terminal, a second terminal, and a control terminal. In the on-state of the MOSFET, current flows from the first terminal to the second terminal. For a P-type MOSFET, the first terminal, second terminal, and control terminal are the source, drain, and gate, respectively; for an N-type MOSFET, the first terminal, second terminal, and control terminal are the drain, source, and gate, respectively. A switch is a transistor that operates in switching mode to provide a current path, including one selected from bipolar transistors or field-effect transistors. The first and second terminals of the switch are respectively a high-potential terminal and a low-potential terminal on the current path. A control terminal is used to receive a drive signal to control the switch's on and off states. A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) consists of a first terminal, a second terminal, and a control terminal. When the MOSFET is turned on, current flows from the first terminal to the second terminal. For a P-type MOSFET, the first terminal is the source, the second terminal is the drain, and the control terminal is the gate, respectively. For an N-type MOSFET, the first terminal is the drain, the second terminal is the source, and the control terminal is the gate.

[0040] Furthermore, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0041] Figure 4 A schematic diagram of a display device including the driving circuit of an embodiment of this application is shown. The display device includes a display panel 110, a gate driving circuit 120, a source driving circuit 130, a timing control circuit 140, and a driving circuit, which includes a temperature detection unit 150 and a substrate control unit 160.

[0042] The display panel 110 includes a display area 111 and a non-display area. The display area 111 includes, for example, a plurality of pixel units 102 arranged in an array. Generally, the pixel unit 102 mainly includes a driving transistor, a light-emitting element, a switching transistor, and a capacitor. In this embodiment, the light-emitting element is selected from, for example, any one of organic light-emitting diodes (OLEDs), light-emitting diodes (LEDs), active-matrix organic light-emitting diodes (AMOLEDs), micro LEDs, or mini LEDs.

[0043] The gate drive circuit 120 is connected to multiple scan lines and provides multiple gate drive signals Vscan to turn on or off multiple pixel units 102 connected to the corresponding scan lines.

[0044] The source drive circuit 130 is connected to multiple data lines. When multiple pixel units 102 are turned on, it provides data voltage Vdata to the corresponding pixel unit 102 to provide image signals to the corresponding pixel unit 102, thereby displaying the image.

[0045] The timing control circuit 140 receives display data from the front end, for example, via a data interface, and generates timing signals and control signals based on the display data. The timing control circuit 140 is connected to the gate drive circuit 120 and the source drive circuit 130, thereby providing corresponding timing signals and control signals to the gate drive circuit 120 and the source drive circuit 130.

[0046] Temperature detection unit 150 is located, for example, in a non-display area on display panel 110 and is symmetrically distributed on both sides of display area 111. It is configured to detect the temperature of display panel 110 to obtain temperature detection signal Vfb.

[0047] The substrate control unit 160 is connected to the substrate of the driving transistor. Based on the temperature detection signal Vfb provided by the temperature detection unit 150, it generates an adjustment signal Vsub to adjust the substrate voltage of the driving transistor, thereby changing the light-emitting current flowing through the light-emitting element.

[0048] For example, the pixel unit 102 included in the display panel 110 is divided into a plurality of substrate control regions. Each substrate control region includes a plurality of pixel units arranged in an array, and each substrate control region is connected to a substrate control unit 160. The substrate control unit 160 provides an adjustment signal Vsub to the corresponding substrate control region to adjust the substrate voltage of the driving transistor in the corresponding substrate control region.

[0049] Optionally, the substrate control unit 160 is also connected to the timing control circuit 140. The timing control unit 140 provides a temporary register value, and the substrate control unit 160 configures an adjustment signal Vsub according to the temporary register value. After stopping operation, the temporary register value is reset to a preset value. In the driving circuit of the display panel provided in this application, the substrate control unit 160 changes the substrate voltage of the driving transistor in the pixel unit 102 according to the temperature detection signal Vfb provided by the temperature detection unit 150, thereby changing the current driving capability of the driving transistor. When the temperature of the display panel 110 rises, the current driving capability of the driving transistor is reduced to reduce the light-emitting current flowing through the light-emitting element, thereby ensuring that the brightness of the display panel 110 remains stable when the temperature changes.

[0050] Specifically, see Figures 5a to 6 , Figure 5aA schematic diagram of the pixel unit structure according to an embodiment of this application is shown. In one embodiment of this application, the pixel unit 102 includes a first switch T1, a second switch T2, a first capacitor C1, a driving transistor Q1, and a light-emitting element OLED. In this embodiment, the light-emitting element OLED is preferably a silicon-based OLED. The control terminal of the first switch T1 receives a gate driving signal Vscan, and its first terminal receives a data voltage Vdata. The first terminal of the first capacitor C1 receives a driving voltage ELVDD, and its second terminal is connected to the second terminal of the first switch T1. The control terminal of the driving transistor Q1 is connected to the second terminal of the first switch T1, and its first terminal is connected to the first terminal of the first capacitor C1. The substrate receives an adjustment signal Vsub generated by the substrate control unit 160. The second switch T2 is, for example, selected from transistors, and its first terminal is connected to the second terminal of the driving transistor Q1. The first terminal of the light-emitting element OLED is connected to the second terminal of the second switch T2, and its second terminal receives a common ground voltage ELVSS. The driving transistor Q1 is, for example, selected from a P-channel MOS transistor.

[0051] In this embodiment, the adjustment signal Vsub is equal to the sum of the driving voltage ELVDD and the preset voltage ΔV. The preset voltage ΔV is, for example, derived from a pre-set lookup table representing the relationship between temperature and preset voltage. In this lookup table, temperature and preset voltage are positively correlated. For example, when the temperature is 25°C, the preset voltage ΔV = 1V; when the temperature is greater than 25°C, the preset voltage ΔV = 1.5V; and when the temperature is less than 25°C, the preset voltage ΔV = 0.5V.

[0052] When the gate drive signal Vscan is active, the first switch T1 is turned on, and the data voltage Vdata charges the first capacitor C1 through the first switch T1. At the same time, it drives the transistor Q1 and the second switch T2 to turn on, so that the light-emitting element OLED displays the corresponding brightness. For example, the light-emitting time of the light-emitting element OLED can be adjusted by controlling the turning on and off of the second switch T2.

[0053] Furthermore, Figure 5a The pixel unit 102 shown can be equivalent to Figure 5b , Figure 5b It shows Figure 5a The equivalent circuit diagram of the pixel unit is shown. The pixel unit 102 includes a voltage-controlled current source (VCCS) and a light-emitting element (OLED). The first terminal of the VCCS receives a driving voltage ELVDD. The first terminal of the OLED is connected to the second terminal of the VCCS, and the second terminal receives a common ground voltage ELVSS. The VCCS is controlled, for example, by an adjustment signal Vsub provided by the substrate control unit 160, and changes the magnitude of the current flowing through the OLED according to the adjustment signal Vsub, thereby changing the brightness of the OLED.

[0054] Figure 6 It shows Figure 4 A schematic diagram of the substrate control unit 160 is shown. The substrate control unit 160 includes a compensation voltage Vcp calculation module 161 and a voltage conversion module 162. The compensation voltage Vcp calculation module 161 is connected to the temperature detection unit 150 to receive the temperature detection signal Vfb generated by the temperature detection unit 150, compares the temperature detection signal Vfb with a set temperature threshold, and calculates the corresponding compensation voltage Vcp based on the comparison result. The voltage conversion module 162 is connected to the compensation voltage Vcp calculation module 161, receives the compensation voltage Vcp generated by the compensation voltage Vcp calculation module 161, converts the compensation voltage Vcp, and generates an adjustment signal Vsub based on the converted voltage, thereby changing the substrate voltage of the driving transistor Q1 in the pixel unit 102. In this embodiment, the voltage conversion module 162 is, for example, selected from a low dropout linear regulator.

[0055] See Figure 7 , Figure 7 The present application illustrates a driving method for a display panel according to an embodiment of this application, which is described below in conjunction with... Figures 4 to 6 The driving method for the display panel in this embodiment will be described as follows:

[0056] In step S10, the temperature of the display panel 110 is detected to obtain a temperature detection signal Vfb.

[0057] When the display device is working, the temperature detection unit 150 arranged around the display area 111 detects the temperature of the display panel 110 and generates a temperature detection signal Vfb based on the detected temperature. That is, the temperature detection signal Vfb can characterize the temperature of the display panel 110.

[0058] In step S20, the substrate voltage of the driving transistor Q1 is adjusted according to the temperature detection signal Vfb to change the light emission current of the light-emitting element OLED.

[0059] Let the luminous current be Id, then from the simplified model formula of Sub threshold, we can obtain...

[0060] Id∝E q(VG-VT) / (K*T)

[0061] Where VT=VT0+γ*(√(2*θ) f +V SB )-√(2*θ f ))

[0062] In the above formula, q is selected from the electron charge (1.602 * 10^6). -19C), VG is selected from the gate voltage, K is selected from the Boltzmann constant, T is selected from the temperature in Kelvin, VT is the current threshold voltage, VT0 is the initial threshold voltage, and θ f Selected from the surface potential correlation coefficient, V SB Selected from the voltage difference between the body voltage and the source voltage.

[0063] Where, γ≡√(2*q*N) A *ε s ) / Cox, N A Avogadro's constant, ε s Relative permittivity, Cox is the capacitance per unit area of ​​oxide layer.

[0064] It is evident that the current driving capability of the driving transistor Q1 can be altered by changing its substrate voltage. For example, when the driving transistor Q1 is selected as a P-channel MOSFET, the higher the substrate voltage, the weaker its current driving capability. Figure 1a as well as Figure 1b It is known that when the temperature of the display panel 110 rises (for example, above 25°C), the light-emitting current flowing through the light-emitting element OLED increases. In order to reduce the light-emitting current flowing through the light-emitting element OLED, the substrate control unit 160 increases the adjustment signal Vsub it provides to the driving transistor Q1 to increase the substrate voltage of the driving transistor Q1 and reduce its current driving capability, thereby keeping the light-emitting current flowing through the light-emitting element OLED at 25mA, ensuring that the brightness of the display area 111 can remain stable even when the temperature rises.

[0065] Specifically, step S20 includes steps S21 and S22.

[0066] In step S21, the temperature detection signal Vfb is compared with the set temperature threshold, and the corresponding compensation voltage Vcp is calculated based on the comparison result.

[0067] The compensation voltage Vcp calculation module 161 in the substrate control unit 160 receives the temperature detection signal Vfb, compares the temperature detection signal Vfb with the set temperature threshold, and calculates the corresponding compensation voltage Vcp based on the comparison result.

[0068] When the driving transistor Q1 is selected from a P-channel MOSFET, the higher the temperature represented by the temperature detection signal Vfb, the higher the compensation voltage Vcp.

[0069] When the driving transistor Q1 is selected from an N-channel MOSFET, the higher the temperature represented by the temperature detection signal Vfb, the lower the compensation voltage Vcp.

[0070] In step S22, the compensation voltage Vcp is converted, and the substrate voltage of the driving transistor Q1 is adjusted according to the converted voltage.

[0071] The voltage conversion module 162 receives the compensation voltage Vcp provided by the compensation voltage calculation module 161, converts the compensation voltage Vcp into an adjustment signal Vsub, and provides the adjustment signal Vsub to the substrate of the driving transistor Q1 in the pixel unit 102 to change the substrate voltage of the driving transistor Q1, thereby adjusting its current driving capability.

[0072] Further, see Figure 8 as well as Figure 9 , Figure 8 The current-voltage characteristic curves of the driving transistor in the embodiments of this application are shown. Figure 8 In the example where the driving transistor Q1 is a P-channel MOSFET, the vertical axis represents the logarithmic light-emitting current Id, and the horizontal axis represents the gate-source voltage VGS. When the gate-source voltage VGS is selected from the threshold voltage VTH, the light-emitting current Id at a substrate voltage of VT_ELVDD is greater than that at a substrate voltage of VT_ELVDD+1V, and the light-emitting current Id at a substrate voltage of VT_ELVDD+1V is greater than that at a substrate voltage of VT_ELVDD+2V. It is evident that the higher the substrate voltage, the weaker the current driving capability of the driving transistor Q1, and the smaller the light-emitting current Id flowing through the OLED element.

[0073] Figure 9 The brightness-voltage characteristic curves of the light-emitting element at different temperatures in the embodiments of this application are shown, and... Figure 1a As can be seen from the comparison, the brightness-voltage characteristic curves of the display panel using the driving circuit and driving method provided in the embodiments of this application almost overlap at different temperatures, and the brightness of the light-emitting element is independent of temperature, thus achieving the requirement that the OLED light-emitting element has the same brightness at different temperatures.

[0074] Furthermore, Figure 10This diagram illustrates the structure of a pixel unit according to another embodiment of this application. The pixel unit 102 includes a first switch T1, a first capacitor C1, a driving transistor Q1, and a light-emitting element OLED. The control terminal of the first switch T1 receives a gate driving signal Vscan, and its first terminal receives a data voltage Vdata. The first terminal of the first capacitor C1 is connected to the second terminal of the first switch T1, and the second terminal is grounded. The driving transistor Q1 is, for example, selected from a P-channel MOSFET. Its control terminal is connected to the second terminal of the first switch T1, and its first terminal receives a driving voltage ELVDD. The substrate receives an adjustment signal Vsub provided by the substrate control unit 160. When the temperature rises, the adjustment signal Vsub is, for example, the driving voltage ELVDD plus a positive voltage value (2V). The first terminal of the light-emitting element OLED is connected to the second terminal of the driving transistor Q1, and its second terminal receives a common ground voltage ELVSS.

[0075] Figure 11 A schematic diagram of a pixel unit according to another embodiment of this application is shown. Pixel unit 102 includes a first switch T1, a first capacitor C1, a driving transistor Q1, and a light-emitting element OLED. The control terminal of the first switch T1 receives a gate driving signal Vscan, and its first terminal receives a data voltage Vdata. The first terminal of the first capacitor C1 is connected to the second terminal of the first switch T1, and the second terminal is grounded. The driving transistor Q1 is, for example, selected from an N-channel MOSFET. Its control terminal is connected to the second terminal of the first switch T1, and its first terminal receives a driving voltage ELVDD. The substrate receives an adjustment signal Vsub provided by the substrate control unit 160. When the temperature rises, the adjustment signal Vsub is, for example, a negative voltage value (-2V). The first terminal of the light-emitting element OLED is connected to the second terminal of the driving transistor Q1, and the second terminal receives a common ground voltage ELVSS.

[0076] It is easy to know that when the driving transistor Q1 is selected from an N-channel MOSFET, the adjustment signal Vsub = 0 - ΔV, and the preset voltage ΔV comes from a pre-set lookup table that represents the relationship between temperature and preset voltage. For example, when the temperature is 25°C, the preset voltage ΔV = 1V, when the temperature is greater than 25°C, the preset voltage ΔV = 1.5V, and when the temperature is less than 25°C, the preset voltage ΔV = 0.5V.

[0077] Figure 12A schematic diagram of a pixel unit according to another embodiment of this application is shown. Pixel unit 102 includes a first switch T1, a second switch T2, a first capacitor C1, a driving transistor Q1, and a light-emitting element OLED. The control terminal of the first switch T1 receives a gate driving signal Vscan, and its first terminal receives a data voltage Vdata. The first terminal of the first capacitor C1 receives a driving voltage ELVDD, and its second terminal is connected to the second terminal of the first switch T1. The driving transistor Q1 is, for example, selected from an N-channel MOSFET. Its control terminal is connected to the second terminal of the first switch T1, and its first terminal is connected to the first terminal of the first capacitor C1. The substrate receives an adjustment signal Vsub generated by the substrate control unit 160. When the temperature rises, the adjustment signal Vsub is, for example, a negative voltage value (-2V). The first terminal of the second switch T2 is connected to the second terminal of the driving transistor Q1. The first terminal of the light-emitting element OLED is connected to the second terminal of the second switch T2, and its second terminal receives a common ground voltage ELVSS.

[0078] In summary, the driving circuit and driving method of the display panel provided in this application allow the substrate control unit 160 to change the substrate voltage of the driving transistor in the pixel unit 102 according to the temperature detection signal Vfb provided by the temperature detection unit 150, thereby changing the current driving capability of the driving transistor. When the temperature of the display panel 110 rises, the current driving capability of the driving transistor is reduced to decrease the light emission current, thereby ensuring that the brightness of the display panel 110 remains stable when the temperature changes.

[0079] Optionally, the driving circuit and driving method of the display panel provided in this application change the substrate voltage of the driving transistor Q1 by providing different adjustment signals Vsub through the substrate control unit 160, thereby changing its current driving capability. When the temperature of the display panel 110 increases (e.g., above 25°C) and the light-emitting current flowing through the light-emitting element OLED increases, in order to reduce the light-emitting current flowing through the light-emitting element OLED, the substrate control unit 160 increases the adjustment signal Vsub provided to the driving transistor Q1 to increase the substrate voltage of the driving transistor Q1 and reduce its current driving capability, thereby keeping the light-emitting current flowing through the light-emitting element OLED at 25mA, ensuring that the brightness of the display area 111 remains stable even when the temperature rises.

[0080] It should be noted that those skilled in the art will understand that the terms “during,” “when,” and “when…” used herein in relation to circuit operation are not strict terms indicating an action that occurs immediately upon the commencement of a startup action, but rather that there may be some small but reasonable delays, such as various propagation delays, between the startup action and the reaction action initiated by it. The terms “approximately” or “substantially” used herein mean that an element value is expected to be close to the declared value or position. However, as is well known in the art, there are always small deviations that make it difficult for the value or position to be strictly the declared value. It has been properly determined in the art that a deviation of at least ten percent (10%) (or at least twenty percent (20%) for semiconductor doping concentration) is a reasonable deviation from the described accurate ideal target. When used in conjunction with signal states, the actual voltage value or logic state of the signal (e.g., “1” or “0”) depends on whether positive or negative logic is used.

[0081] As described above, these embodiments of the present invention do not exhaustively describe all details, nor do they limit the invention to specific embodiments. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to effectively utilize the invention and its modifications. The scope of protection of this invention should be determined by the scope defined in the claims and their equivalents.

Claims

1. A driving circuit for a display panel, wherein, The display panel includes multiple substrate control regions, each substrate control region including multiple pixel units arranged in an array, each pixel unit including a connected driving transistor and a light-emitting element, the driving circuit including: A temperature detection unit is used to detect the temperature of the display panel to obtain a temperature detection signal; and A substrate control unit, connected to the corresponding substrate control region, is used to adjust the substrate voltage of the driving transistor according to the temperature detection signal, so as to maintain the light emission current of the light-emitting element from changing with the temperature.

2. The driving circuit according to claim 1, wherein, The driving transistor is a P-channel MOS transistor. The substrate control unit is configured such that the substrate voltage of the driving transistor increases as the temperature of the display panel increases.

3. The driving circuit according to claim 1, wherein, The driving transistor is an N-channel MOS transistor. The substrate control unit is configured such that the substrate voltage of the driving transistor decreases as the temperature of the display panel increases.

4. The driving circuit according to claim 2 or 3, wherein, The substrate control unit includes: The compensation voltage calculation module is used to compare the temperature detection signal with a set temperature threshold and calculate the corresponding compensation voltage based on the comparison result; and A voltage conversion module is used to convert the compensation voltage to generate an adjustment signal, and adjust the substrate voltage of the driving transistor according to the adjustment signal.

5. The driving circuit according to claim 4, wherein, The adjustment signal is the sum of the driving voltage and the preset voltage, and the preset voltage is positively correlated with the temperature.

6. The driving circuit according to claim 4, wherein, The voltage conversion module is implemented using a low-dropout linear regulator.

7. A method for driving a display panel, wherein, The display panel includes multiple substrate control regions, each substrate control region including multiple pixel units arranged in an array, each pixel unit including a connected driving transistor and a light-emitting element, wherein the driving method includes: Detecting the temperature of the display panel to obtain a temperature detection signal; and The substrate voltage of the driving transistor in the corresponding substrate control region is adjusted according to the temperature detection signal to maintain the light-emitting current of the light-emitting element from changing with the temperature.

8. The driving method according to claim 7, wherein, The driving transistor is a P-channel MOS transistor. The step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: This causes the substrate voltage of the driving transistor to increase as the temperature of the display panel increases.

9. The driving method according to claim 7, wherein, The driving transistor is an N-channel MOS transistor. The step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: This causes the substrate voltage of the driving transistor to decrease as the temperature of the display panel increases.

10. The driving method according to claim 8 or 9, wherein, The step of adjusting the substrate voltage of the driving transistor according to the temperature detection signal includes: The temperature detection signal is compared with a set temperature threshold, and the corresponding compensation voltage is calculated based on the comparison result; and The compensation voltage is voltage-converted to generate an adjustment signal, and the substrate voltage of the driving transistor is adjusted according to the adjustment signal.

11. The driving method according to claim 10, wherein, The adjustment signal is the sum of the driving voltage and the preset voltage, and the preset voltage is positively correlated with the temperature.

12. The driving method according to claim 10, wherein, The step of voltage conversion of the compensation voltage includes: The compensation voltage is converted using a low-dropout linear regulator.

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