Dimming control circuit and control method, and display device

Abstract

A dimming control circuit (3) and control method, and a display device (1), relating to the technical field of display. The display brightness of the display device (1) has a first brightness range and a second brightness range, the minimum value of the first brightness range being greater than the maximum value of the second brightness range. The control method comprises: the dimming control circuit (3) receives a display brightness signal and a pulse width modulation signal. The display brightness signal comprises a display brightness value. When the display brightness value is within the first brightness range, the effective width of the pulse width modulation signal does not change along with the change of the display brightness value. When the display brightness value is within the second brightness range, the effective width of the pulse width modulation signal is positively correlated with the display brightness value. The control method is applied to the display device (1) to control the display brightness of the display device (1).

Description

Dimming control circuit and control method thereof, and display device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on June 29, 2023, with application number 202310794501.0 and application name “Dimming control circuit, control method thereof, and display device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of display technology, and in particular to a dimming control circuit and a control method thereof, and a display device. Background Art

[0003] In environments with different light intensities, the human eye has different requirements for the display brightness of display devices. For example, under the premise that the human eye can see the display image clearly, the display brightness of the display device only needs to be set to 100nit in the dark, the display brightness of the display device in the bright place is set to 300nit, and the display brightness of the display device in the sun needs to be set to 1000nit.

[0004] Based on this, how to adjust the display brightness while ensuring the display quality has become an urgent problem to be solved in this field.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a dimming control circuit and a control method thereof, and a display device, which achieve adjustment of display brightness.

[0007] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0008] In a first aspect, a dimming control method is provided, which is applied to a display device, wherein the display brightness of the display device has a first brightness range and a second brightness range, and the minimum value of the first brightness range is greater than the maximum value of the second brightness range.

[0009] The control method includes: a dimming control circuit receiving a display brightness signal and outputting a pulse-width modulation signal. The display brightness signal includes a display brightness value. When the display brightness value is within a first brightness range, the effective width of the pulse-width modulation signal does not change with changes in the display brightness value. When the display brightness value is within a second brightness range, the effective width of the pulse-width modulation signal is positively correlated with the display brightness value.

[0010] In the dimming control method provided in the above-mentioned embodiments of the present application, the dimming control circuit receives a display brightness signal and adopts a hybrid dimming method to adjust the display brightness value within a first brightness range (for example, a high brightness range). The dimming control circuit does not adjust the effective width of the output pulse width modulation signal according to the change of the display brightness value, but can adjust the display brightness by, for example, grayscale scaling.

[0011] When adjusting the display brightness value within a second brightness range (for example, a low brightness range), the scaling of the grayscale will result in loss of accuracy. Based on this, the dimming control circuit adjusts the effective width of the output pulse width modulation signal according to the change of the display brightness value. For example, the larger the display brightness value, the larger the effective width of the pulse width modulation signal. This can improve the problem of grayscale accuracy loss at low brightness, and realizes the adjustment of display brightness while ensuring the display quality of the display device.

[0012] In some embodiments, when the display brightness value is within the second brightness range, the change rate of the effective width of the pulse width modulation signal is equal to the change rate of the display brightness value.

[0013] In some embodiments, the dimming control circuit includes a gamma correction circuit and a pulse width modulation circuit. The dimming control circuit receives a display brightness signal and outputs a pulse width modulation signal, including: the gamma correction circuit and the pulse width modulation circuit respectively receive the display brightness signal.

[0014] When the display brightness value is within the first brightness range, the gamma correction circuit receives the data signal and outputs the data correction signal, the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the first ratio of the display brightness value to the maximum display brightness; the pulse width modulation circuit receives the data correction signal and outputs the pulse width modulation signal; or,

[0015] When the display brightness value is within the second brightness range, the gamma correction circuit receives the data signal and outputs the data correction signal, and the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the second ratio of the maximum value of the second brightness range to the highest display brightness; the pulse width modulation circuit receives the data correction signal, generates an initial pulse width modulation signal, and outputs the pulse width modulation signal based on the initial pulse width modulation signal, and the ratio of the effective width of the pulse width modulation signal to the effective width of the initial pulse width modulation signal is equal to the third ratio of the display brightness value to the maximum value of the second brightness range.

[0016] The dimming control method provided in the above-mentioned embodiment of the present application adopts a hybrid dimming method, wherein the display brightness signal is input into the gamma correction circuit and the pulse width modulation circuit, and the gamma correction circuit and the pulse width modulation circuit respectively determine whether the display brightness value is within the first brightness range or the second brightness range.

[0017] When the display brightness value is within the first brightness range (high brightness range), the gamma correction circuit proportionally scales the grayscale of the data signal based on the ratio of the display brightness value to the maximum display brightness to generate a data correction signal. The pulse width modulation circuit receives the data correction signal and outputs a corresponding pulse width modulation signal to control the duration of the drive current flowing in the pixel circuit to adjust the display brightness of the display device. In other words, within the high brightness range, the display brightness of the display device can be adjusted by proportionally scaling the grayscale of the data signal.

[0018] However, when the display brightness value is within the second brightness range, that is, within the low brightness range, continuing to perform proportional scaling mapping on the grayscale of the data signal according to the ratio of the display brightness value to the maximum display brightness will result in the loss of grayscale accuracy of the data signal, affecting the display quality of the image.

[0019] Based on this, within the low brightness range, regardless of the display brightness adjustment value, the gamma correction circuit proportionally scales the grayscale of the data signal based on the ratio of the maximum value in the second brightness range to the maximum display brightness, generating a data correction signal. This can improve the problem of loss of grayscale accuracy in the data signal. The pulse width modulation circuit receives the data correction signal and proportionally scales the effective width of the initial pulse width modulation signal based on the ratio of the display brightness value to the maximum value in the second brightness range, generating a pulse width modulation signal. This is used to control the duration of the drive current flowing in the pixel circuit, thereby adjusting the display brightness of the display device.

[0020] It can be seen that the hybrid dimming method can improve the problem of grayscale accuracy loss at low brightness, and realize the adjustment of display brightness while ensuring the display quality of the display device.

[0021] In some embodiments, after the gamma correction circuit receives the display brightness signal, the control method further includes: determining whether the display brightness value is within the first brightness range or the second brightness range.

[0022] In some embodiments, after the pulse width modulation circuit receives the display brightness signal, the control method further includes: determining whether the display brightness value is within the first brightness range or the second brightness range.

[0023] In some embodiments, the data correction signal includes multiple bits, and when the display brightness value is within a second brightness range, the pulse width modulation circuit receives the data correction signal, generates an initial pulse width modulation signal, and outputs the pulse width modulation signal based on the initial pulse width modulation signal, including: the pulse width modulation circuit receives the data correction signal, generates multiple initial pulse width modulation sub-signals corresponding to the multiple bits, generates multiple corresponding pulse width modulation sub-signals based on the multiple initial pulse width modulation sub-signals, and obtains the pulse width modulation signal based on the multiple pulse width modulation sub-signals. The ratio of the effective width of the pulse width modulation sub-signal to the effective width of the corresponding initial pulse width modulation sub-signal is equal to the third ratio.

[0024] In a second aspect, a dimming control circuit is provided. The dimming control circuit is configured to receive a display brightness signal and output a pulse-width modulation signal. The display brightness signal includes a display brightness value. When the display brightness value is within a first brightness range, the effective width of the pulse-width modulation signal does not change with changes in the display brightness value. When the display brightness value is within a second brightness range, the effective width of the pulse-width modulation signal is positively correlated with the display brightness value, and the minimum value of the first brightness range is greater than the maximum value of the second brightness range.

[0025] In the above-mentioned embodiments of the present application, the dimming control circuit receives a display brightness signal and outputs a pulse width modulation signal. The dimming control circuit adopts a mixed dimming method to adjust the display brightness value within a first brightness range (for example, a high brightness range). The dimming control circuit does not adjust the effective width of the pulse width modulation signal according to the change of the display brightness value, but can adjust the display brightness by, for example, grayscale scaling.

[0026] When adjusting the display brightness value within the second brightness range (for example, the low brightness range), the scaling of the grayscale will cause loss of accuracy. Based on this, the dimming control circuit adjusts the effective width of the pulse width modulation signal according to the change of the display brightness value. For example, the larger the display brightness value, the larger the effective width of the pulse width modulation signal. This can improve the problem of loss of grayscale accuracy at low brightness, and realizes the adjustment of display brightness while ensuring the display quality of the display device.

[0027] In some embodiments, the control circuit includes a gamma correction circuit and a pulse width modulation circuit, both of which are configured to receive a display brightness signal.

[0028] The gamma correction circuit is further configured to receive a data signal and output a data correction signal when the display brightness value is within a first brightness range, wherein a ratio of a grayscale of the data correction signal to a grayscale of the data signal is equal to a first ratio. The pulse width modulation circuit is further configured to receive the data correction signal and output a pulse width modulation signal.

[0029] Alternatively, the gamma correction circuit is further configured to receive a data signal and output a data correction signal when the display brightness value is within a second brightness range, wherein the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the second ratio. The pulse width modulation circuit is further configured to receive the data correction signal, generate an initial pulse width modulation signal, and output a pulse width modulation signal based on the initial pulse width modulation signal, wherein the ratio of the effective width of the pulse width modulation signal to the effective width of the initial pulse width modulation signal is equal to a third ratio.

[0030] The control circuit, gamma correction circuit and pulse width modulation circuit provided in the above embodiments of the present application all receive a display brightness signal, and the gamma correction circuit and pulse width modulation circuit respectively determine whether the display brightness value is within the first brightness range or the second brightness range.

[0031] When the display brightness value is within the first brightness range (high brightness range), the gamma correction circuit proportionally scales the grayscale of the data signal based on the ratio of the display brightness value to the maximum display brightness to generate a data correction signal. The pulse width modulation circuit receives the data correction signal and outputs a corresponding pulse width modulation signal to control the duration of the drive current flowing in the pixel circuit to adjust the display brightness of the display device. In other words, within the high brightness range, the display brightness of the display device can be adjusted by proportionally scaling the grayscale of the data signal.

[0032] When the display brightness value is within the second brightness range (low brightness range), regardless of the display brightness value adjustment, the gamma correction circuit proportionally scales the grayscale of the data signal according to the ratio of the maximum value in the second brightness range to the maximum display brightness, thereby generating a data correction signal. This can improve the problem of loss of grayscale accuracy of the data signal. The pulse width modulation circuit receives the data correction signal and proportionally scales the effective width of the initial pulse width modulation signal according to the ratio of the display brightness value to the maximum value in the second brightness range, thereby generating a pulse width modulation signal. This is used to control the duration of the driving current flowing in the pixel circuit to adjust the display brightness of the display device.

[0033] In some embodiments, the gamma correction circuit includes a first determination subcircuit and a search subcircuit. The first determination subcircuit is configured to receive a display brightness signal and determine whether the display brightness value is within a first brightness range or a second brightness range. If the display brightness value is within the first brightness range, the first control signal including a first ratio is output. If the display brightness value is within the second brightness range, the second control signal including a second ratio is output.

[0034] The search subcircuit is electrically connected to the first determination subcircuit. The search subcircuit is configured to receive a first control signal and a data signal and output a data correction signal based on the first ratio and a grayscale of the data signal. Alternatively, the search subcircuit is configured to receive a second control signal and a data signal and output a data correction signal based on the second ratio and a grayscale of the data signal.

[0035] In some embodiments, the pulse width modulation circuit includes a second determination subcircuit and a control subcircuit. The second determination subcircuit is configured to receive a display brightness signal and determine whether the display brightness value is within a first brightness range or a second brightness range. If the display brightness value is within the second brightness range, the second determination subcircuit is configured to output a third control signal including a third ratio.

[0036] The control subcircuit is electrically connected to the second judgment subcircuit, and the control subcircuit is configured to receive a third control signal and a data correction signal, generate an initial pulse width modulation signal according to the grayscale of the data correction signal, and output the pulse width modulation signal according to the third ratio and the effective width of the initial pulse width modulation signal.

[0037] In a third aspect, a dimming control method is provided. The dimming control method includes: a dimming control circuit receiving a display brightness signal and outputting a driving current. The display brightness signal includes a display brightness value, and each brightness interval of the display brightness value corresponds to a driving current. Different brightness intervals correspond to different driving currents.

[0038] In the dimming control method provided in the above-mentioned embodiments of the present application, the dimming control circuit receives a display brightness signal and outputs a corresponding driving current based on the correspondence between the brightness interval in which the display brightness value is located and the driving current. Different brightness intervals correspond to different driving currents, thereby achieving display brightness adjustment and improving the problem of grayscale accuracy loss at low brightness.

[0039] In some embodiments, the plurality of brightness intervals include a first brightness interval to an nth brightness interval that sequentially change from low to high, where n≥2. The magnitude of the driving current is positively correlated with i, where 1≤i≤n, and i is a positive number.

[0040] In some embodiments, a dimming control circuit includes a gamma correction circuit, a pulse width modulation circuit, a current control circuit, and a pixel circuit. The dimming control circuit receives a display brightness signal and outputs a driving current. The gamma correction circuit receives the display brightness signal and a data signal and outputs a data correction signal. The display brightness signal includes a display brightness value and a display brightness ratio. The display brightness ratio is the ratio of the display brightness value to the maximum display brightness. The ratio of the grayscale of the data correction signal to the grayscale of the data signal is a target ratio, and the target ratio is greater than the display brightness ratio. The pulse width modulation circuit receives the data correction signal and outputs a pulse width modulation signal.

[0041] The current control circuit receives a display brightness signal and outputs a current control signal. The first through nth brightness intervals correspond to the first through nth drive currents, with the first through nth drive currents varying sequentially from low to high. When the display brightness value is within the i-th brightness interval, 1 ≤ i ≤ n, the current control circuit outputs the i-th current control signal corresponding to the i-th drive current.

[0042] The pixel circuit receives a pulse width modulation signal and an i-th current control signal, and outputs an i-th driving current to control the display brightness of the display device.

[0043] The control method provided by the above-mentioned embodiment of the present application adopts a hybrid dimming method. The gamma correction circuit receives a display brightness signal and a data signal, and scales and maps the grayscale of the data signal at a target ratio greater than the display brightness ratio to obtain a data correction signal. At lower brightness, the grayscale of the data signal is scaled and mapped at a target ratio that is relatively large relative to the display brightness. After scaling and mapping, the grayscale value range is larger, thereby improving the problem of grayscale accuracy loss at low brightness. The pulse width modulation circuit receives the data correction signal and outputs a pulse width modulation signal. The pixel circuit receives the pulse width modulation signal to control the duration of the drive current.

[0044] Furthermore, the display brightness value of the display device is divided into multiple brightness intervals that vary from low to high. These multiple brightness intervals correspond one-to-one to multiple drive currents, and these multiple drive currents vary from low to high. That is, the larger the brightness interval, the larger the corresponding drive current. Based on this, the current control circuit receives the display brightness signal and outputs a current control signal corresponding to the drive current based on the brightness interval in which the display brightness value is located and its corresponding drive current. The pixel circuit receives the current control signal and outputs the corresponding drive current, thereby adjusting the magnitude of the drive current.

[0045] It can be seen that by adopting the above-mentioned hybrid dimming method, the size of the driving current and the duration of the driving current flowing through the light-emitting chip can be adjusted respectively, which can improve the problem of loss of grayscale accuracy at low brightness, and realize the adjustment of display brightness while ensuring the display quality of the display device.

[0046] In some embodiments, a one-to-one correspondence between display brightness values ​​and target ratios is stored in the gamma correction circuit, and the display brightness values ​​are proportional to the target ratios.

[0047] The gamma correction circuit receives a display brightness signal and a data signal and outputs a data correction signal. The gamma correction circuit receives the display brightness signal and, based on a corresponding relationship, obtains a target ratio corresponding to a display brightness value in the display brightness signal. The gamma correction circuit also receives the data signal and, based on the target ratio, outputs the data correction signal.

[0048] In some embodiments, after the current control circuit receives the display brightness signal, the control method further includes: determining a brightness interval in which the display brightness value is located.

[0049] In a fourth aspect, a display brightness control circuit is provided. The control circuit is applied to a display device having a first brightness interval to an nth brightness interval that change sequentially from low to high, where n≥2.

[0050] The control circuit includes a gamma correction circuit, a pulse width modulation circuit, a current control circuit and a pixel circuit.

[0051] The gamma correction circuit is configured to receive a display brightness signal and a data signal and output a data correction signal. The display brightness signal includes a display brightness value and a display brightness ratio. The display brightness ratio is the ratio of the display brightness value to the maximum display brightness. The ratio of the grayscale of the data correction signal to the grayscale of the data signal is a target ratio, and the target ratio is greater than the display brightness ratio. The pulse width modulation circuit is configured to receive the data correction signal and output a pulse width modulation signal.

[0052] The current control circuit is configured to receive a display brightness signal and output a current control signal, wherein the first to nth brightness intervals correspond to the first to nth drive currents, and the first to nth drive currents vary sequentially from low to high. When the display brightness value is in the i-th brightness interval, 1≤i≤n, the current control signal is the i-th current control signal corresponding to the i-th drive current.

[0053] The pixel circuit is configured to receive a pulse width modulation signal and an i-th current control signal, and output an i-th driving current to control display brightness.

[0054] In the control circuit provided by the above-described embodiments of the present application, the gamma correction circuit receives a display brightness signal and a data signal. At lower brightness levels, the gamma correction circuit scales the grayscale of the data signal using a target ratio that is relatively large relative to the display brightness. This scaling results in a wider grayscale range, thereby improving the problem of grayscale accuracy loss at low brightness levels. The pulse width modulation circuit receives the data correction signal and outputs a pulse width modulation signal. The pixel circuit receives the pulse width modulation signal to control the duration of the drive current.

[0055] Furthermore, the display brightness value of the display device is divided into multiple brightness intervals that vary from low to high. These multiple brightness intervals correspond one-to-one to multiple drive currents, and these multiple drive currents vary from low to high. That is, the larger the brightness interval, the larger the corresponding drive current. Based on this, the current control circuit receives the display brightness signal and outputs a current control signal corresponding to the drive current based on the brightness interval in which the display brightness value is located and its corresponding drive current. The pixel circuit receives the current control signal and outputs the corresponding drive current, thereby adjusting the magnitude of the drive current.

[0056] The display brightness is adjusted by adjusting the magnitude of the driving current and the duration for which the driving current flows through the light-emitting chip.

[0057] In some embodiments, the pixel circuit includes a current source electrically connected to the current control circuit, and the current source is configured to receive an i-th current control signal and output an i-th driving current.

[0058] In a fifth aspect, a display device is provided, comprising a display panel and a dimming control circuit according to any one of the above embodiments. The display panel comprises a plurality of light-emitting chips, and the dimming control circuit is electrically connected to the light-emitting chips.

[0059] It can be understood that the beneficial effects that can be achieved by the display device provided by the above embodiments of the present application can refer to the beneficial effects of the control circuit described above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] To more clearly illustrate the technical solutions of this application, the following briefly introduces the drawings required for use in some embodiments of this application. Obviously, the drawings described below are only drawings of some embodiments of this application, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of this application.

[0061] FIG1 is a structural diagram of a display device provided in an embodiment of the present application;

[0062] FIG2 is a structural diagram of a Mini LED / μLED display panel provided in an embodiment of the present application;

[0063] FIG3 is a structural block diagram of a dimming control circuit provided in an embodiment of the present application;

[0064] FIG4 is a structural block diagram of another dimming control circuit provided in an embodiment of the present application;

[0065] FIG5 is a flow chart of a dimming control method provided in an embodiment of the present application;

[0066] FIG6 is a block diagram of a gamma correction circuit according to an embodiment of the present application;

[0067] FIG7 is a block diagram of a pulse width modulation circuit according to an embodiment of the present application;

[0068] FIG8 is a working principle diagram of a gamma correction circuit provided in an embodiment of the present application;

[0069] FIG9 is another working principle diagram of the gamma correction circuit provided in an embodiment of the present application;

[0070] FIG10 is a diagram showing the working principle of a pulse width modulation circuit provided in an embodiment of the present application;

[0071] FIG11 is a structural block diagram of another dimming control circuit provided in an embodiment of the present application;

[0072] FIG12 is a structural block diagram of another dimming control circuit provided in an embodiment of the present application;

[0073] FIG13 is a flow chart of another dimming control method provided in an embodiment of the present application;

[0074] FIG14 is another working principle diagram of the gamma correction circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0075] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the embodiments described are only some embodiments of the present application, not all embodiments. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0076] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as having an open, inclusive meaning, that is, "including, but not limited to." In the description of the specification, the terms "one embodiment," "some embodiments," "exemplary embodiments," "examples," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the particular features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0077] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0078] When describing some embodiments, the word "connected" and its derivatives may be used. The term "connected" should be understood broadly. For example, "connected" can mean fixed, removable, or integrated; it can be directly connected or indirectly connected through an intermediary. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0079] Additionally, the use of “based on” is meant to be open and inclusive, as a process, step, calculation, or other action “based on” one or more stated conditions or values ​​may, in practice, be based on additional conditions or values ​​beyond those stated.

[0080] As used herein, "about" and "approximately" include the stated value and the average value that is within an acceptable range of deviation from the particular value, where the acceptable range of deviation is determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0081] Some embodiments of the present application provide a display device. FIG1 is a structural diagram of a display device provided by an embodiment of the present application.

[0082] Referring to FIG1 , the display device 1 may be, for example, a mobile phone, a tablet computer, a personal digital assistant (PDA), a laser TV, a projector, a smart wearable product (e.g., a smart watch, a smart bracelet), a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a rechargeable small household appliance (e.g., a soymilk maker, a sweeping robot), a drone, a radar, aerospace equipment, and a vehicle-mounted device, among other different types of user devices or terminal devices. The embodiments of the present application do not impose any particular restrictions on the specific form of the electronic device.

[0083] Continuing to refer to FIG1 , the display device 1 includes a display panel 2 . The display device 1 may be a sub-millimeter light-emitting diode (Mini Light-Emitting Diode, Mini LED) display device or a micron light-emitting diode (Micro Light-Emitting Diode, μLED) display device.

[0084] Mini LED / μLED display technology is considered by the industry to be the third generation of display technology after Liquid Crystal Display (LCD) and Organic Light-Emitting Diode (OLED). Mini LED / μLED display devices have advantages such as good display effects, light weight, high contrast and long service life.

[0085] FIG2 is a structural diagram of a Mini LED / μLED display panel provided in an embodiment of the present application.

[0086] 2 , a display panel 2 includes multiple sub-pixels 20 for displaying images. Each sub-pixel 20 includes a light-emitting chip 21, which is a Mini LED / μLED. The display panel 2 can be, for example, a silicon-based microdisplay panel.

[0087] For example, the chip size of Mini LEDs ranges from 50μm to 200μm, while the chip size of μLEDs is less than 100μm. Furthermore, the chip pitch of Mini LEDs is also smaller than that of μLEDs.

[0088] In environments with varying light intensities, the human eye has different requirements for display brightness. For example, if the human eye can clearly see the displayed image, the display brightness of the display device only needs to be set to 100 nits in the dark, 300 nits in bright conditions, and 1000 nits in sunlight. Therefore, the display brightness of the display device needs to be adjusted in application environments with varying light intensities.

[0089] Some embodiments of the present application provide a dimming control circuit and a control method thereof. Figure 3 is a structural block diagram of a dimming control circuit provided by an embodiment of the present application; Figure 4 is a structural block diagram of another dimming control circuit provided by an embodiment of the present application; and Figure 5 is a flow chart of a dimming control method provided by an embodiment of the present application.

[0090] 3 , the display device 1 includes a dimming control circuit 3 , which is configured to receive a display brightness signal V DBV , output pulse width modulation signal (Pulse Width Modulation, PWM).

[0091] Typically, when a user performs an operation to adjust the display brightness, the application processor (AP) generates a display brightness signal V in response to the operation.DBV , and the display brightness signal V DBV Transmitted to the dimming control circuit 3.

[0092] The dimming control circuit 3 is electrically connected to the light emitting chip 21 on the display panel 2 through the pixel circuit 30. The dimming control circuit 3 receives the display brightness signal V DBV and outputs the pulse width modulation signal to the pixel circuit 30, which drives the light emitting chip 21 to emit light.

[0093] Exemplarily, the pixel circuit 30 includes a current source I and a transistor M. The current source I is used to generate a driving current. The pulse width modulation signal from the dimming control circuit 3 is transmitted to the gate of the transistor M. By controlling the conduction or cutoff of the transistor M, the duration of the driving current flowing through the light-emitting chip 21 is controlled, thereby controlling the display brightness of the display device 1.

[0094] In some embodiments, referring to FIG. 4 , the dimming control circuit 3 may include a connected gamma correction circuit 31 and a pulse width modulation circuit 32 .

[0095] Exemplarily, the gamma correction circuit 31 , the pulse width modulation circuit 32 and the pixel circuit 30 may all be integrated into a same chip, which may be disposed on the display panel 2 .

[0096] Exemplarily, the gamma correction circuit 31 , the pulse width modulation circuit 32 and the pixel circuit 30 are directly provided on the display panel 2 in the form of a film structure, which is conducive to making the display panel 2 lighter and thinner.

[0097] For example, the display device 1 further includes a circuit board connected to the display panel 2. The circuit board is used to mount functional components such as an application processor. The gamma correction circuit 31 can be mounted on the circuit board. The pulse width modulation circuit 32 and the pixel circuit 30 can be integrated into a chip or directly mounted on the display panel 2 in the form of a film structure.

[0098] The display brightness of the display device 1 has a first brightness range and a second brightness range, and the minimum value of the first brightness range is greater than the maximum value of the second brightness range. The first brightness range can be understood as a high brightness range, and the second brightness range can be understood as a low brightness range.

[0099] 5 , the dimming control method includes the following steps S10 to S60 :

[0100] S10: The gamma correction circuit 31 and the pulse width modulation circuit 32 receive the display brightness signal V DBV , display brightness signal V DBV Contains the Display Brightness Value (DBV).

[0101] Exemplarily, after S10, the dimming control method further includes the following S11:

[0102] S11: Determine whether the display brightness value is within the first brightness range or the second brightness range.

[0103] FIG6 is a structural block diagram of a gamma correction circuit provided in an embodiment of the present application; FIG7 is a structural block diagram of a pulse width modulation circuit provided in an embodiment of the present application.

[0104] 6 , the gamma correction circuit 31 includes a first judgment subcircuit 311 and a search subcircuit 312. The first judgment subcircuit 311 is configured to receive a display brightness signal V DBV , and determines whether the display brightness value is within the first brightness range or the second brightness range. If the display brightness value is within the first brightness range, the first determination sub-circuit 311 outputs a first control signal including a first ratio, where the "first ratio" is the ratio of the display brightness value to the maximum display brightness.

[0105] It is understood that "maximum display brightness" is a standard parameter of display device 1, representing the maximum brightness that can be achieved by the image displayed by display device 1. For example, if the display brightness value is adjusted to the maximum display brightness, the first ratio is 100%; if the display brightness value is adjusted to half of the maximum display brightness, the first ratio is 50%.

[0106] If the display brightness value is within the second brightness range, the first determination sub-circuit 311 outputs a second control signal including a second ratio, where the second ratio is the ratio of the maximum value of the second brightness range to the highest display brightness.

[0107] 7 , the pulse width modulation circuit 32 includes a second judgment subcircuit 321 and a control subcircuit 322. The second judgment subcircuit 321 is configured to receive the display brightness signal V DBV , and determines whether the display brightness value is within the first brightness range or the second brightness range. If the display brightness value is within the second brightness range, the second determination sub-circuit 321 outputs a third control signal including a third ratio, where the third ratio is the ratio of the display brightness value to the maximum value of the second brightness range.

[0108] If the display brightness value is within the first brightness range, the second determination sub-circuit 321 will not output the third control signal including the third ratio.

[0109] S20: When the display brightness value is within the first brightness range, the gamma correction circuit 31 receives the data signal and outputs a data correction signal, wherein the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the first ratio.

[0110] FIG8 is a diagram showing a working principle of a gamma correction circuit provided in an embodiment of the present application.

[0111] 8 , a gamma correction circuit 31 is used to adjust the grayscale of the data signal in a proportional scaling mapping manner based on a gamma calibration algorithm, so as to adjust the display brightness of the display device 1 in subsequent method steps.

[0112] Exemplarily, when the first ratio is 100%, based on 100% proportional mapping of the gamma calibration algorithm, the grayscale of the data signal is equal to the grayscale of the data correction signal.

[0113] For example, if the grayscale of the data signal is 0 or 1, after 100% proportional mapping, the grayscale of the data correction signal is 0 or 1. Alternatively, if the grayscale of the data signal is 1022 or 1023, after 100% proportional mapping, the grayscale of the data correction signal is 1022 or 1023.

[0114] Exemplarily, when the first ratio is 50%, based on the 50% proportional reduction mapping of the gamma calibration algorithm, the ratio of the grayscale of the data correction signal to the grayscale of the data signal is 50%.

[0115] For example, if the grayscale of the data signal is 0 or 1, after 50% proportional reduction mapping, the grayscale of the data correction signal is 0. Alternatively, if the grayscale of the data signal is 1022 or 1023, after 50% proportional reduction mapping, the grayscale of the data correction signal is 511.

[0116] It can be understood that the ratio of the grayscale (511) of the data correction signal to the grayscale (1023) of the data signal is approximately equal to 50%, that is, the grayscale (1023) of the data signal is mapped down by a ratio of approximately 50% to obtain the grayscale (511) of the data correction signal.

[0117] Continuing with FIG6 , when the display brightness value is within the first brightness range, the first determination subcircuit 311 outputs a first control signal including a first ratio. The search subcircuit 312 is configured to execute S20 above. The search subcircuit 312 is configured to receive the first control signal and the data signal, and output a data correction signal based on the first ratio in the first control signal and the grayscale of the data signal.

[0118] It is understandable that the lookup subcircuit 312 adopts a proportional scaling mapping method, uses a lookup table, and uses the product of the grayscale of the data signal and the first ratio as the lookup table address for table indexing, and the lookup table address corresponds to the data correction signal.

[0119] S30: The pulse width modulation circuit 32 receives the data correction signal and outputs a pulse width modulation signal.

[0120] If the display brightness value is within the first brightness range, the second determination subcircuit 321 does not output the third control signal containing the third ratio. The control subcircuit 322 is configured to perform S30 above. The control subcircuit 322 is configured to receive the data correction signal but not the third control signal. The control subcircuit 322 generates and outputs a corresponding pulse-width modulation signal based on the grayscale of the data correction signal. In this case, the effective width of the pulse-width modulation signal does not change with changes in the display brightness value.

[0121] S40: Alternatively, when the display brightness value is within the second brightness range, the gamma correction circuit 31 receives the data signal and outputs a data correction signal, wherein the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the second ratio.

[0122] FIG9 is another working principle diagram of the gamma correction circuit provided in an embodiment of the present application.

[0123] Referring to FIG9 , taking the second ratio of the maximum value of the second brightness range to the maximum display brightness as 50% as an example, when the display brightness value is within the second brightness range, the ratio of the display brightness value to the maximum display brightness is greater than 0 and less than or equal to 50%. Within this range, the gamma correction circuit 31 performs proportional scaling mapping with the second ratio of 50% to adjust the grayscale of the data signal.

[0124] S50: The PWM circuit 32 receives the data correction signal, generates an initial PWM signal, and outputs a PWM signal based on the initial PWM signal. The ratio of the effective width of the PWM signal to the effective width of the initial PWM signal is equal to the third ratio.

[0125] Continuing with FIG. 7 , when the display brightness value is within the second brightness range, the second determination subcircuit 321 outputs a third control signal including a third ratio. The control subcircuit 322 is configured to execute S50 described above. The control subcircuit 322 is configured to receive the third control signal and the data correction signal, generate an initial pulse-width modulation signal based on the grayscale of the data correction signal, and output the pulse-width modulation signal based on the third ratio and the effective width of the initial pulse-width modulation signal.

[0126] Since the ratio of the display brightness value to the maximum value of the second brightness range is the third ratio, the ratio of the effective width of the PWM signal to the effective width of the initial PWM signal is equal to the third ratio. Therefore, the effective width of the PWM signal is positively correlated with the display brightness value.

[0127] For example, when the display brightness value changes within the second brightness range, the rate of change of the effective width of the pulse width modulation signal is equal to the rate of change of the display brightness value. The "rate of change of the display brightness value" refers to the ratio of the difference between the display brightness value before and after the change to the display brightness value before the change. The "rate of change of the effective width" refers to the ratio of the difference between the effective width of the pulse width modulation signal before and after the change to the effective width of the pulse width modulation signal before the change. For details, see the following embodiments.

[0128] FIG10 is a diagram showing the working principle of a pulse width modulation circuit provided in an embodiment of the present application.

[0129] In some embodiments, referring to FIG. 10 , the data correction signal includes a plurality of bits (0 to n bits). For example, if the grayscale number of the data correction signal is 0 to 1023, the data correction signal includes 10 bits (0 to 9 bits).

[0130] Based on this, the above S50 may include the following S501:

[0131] S501: The pulse width modulation circuit 32 receives a data correction signal and generates a plurality of initial pulse width modulation sub-signals corresponding to a plurality of bits. Based on the plurality of initial pulse width modulation sub-signals, a corresponding plurality of pulse width modulation sub-signals is generated, wherein the ratio of the effective width of the pulse width modulation sub-signal to the effective width of the corresponding initial pulse width modulation sub-signal is equal to a third ratio. The pulse width modulation circuit 32 may further generate a pulse width modulation signal PWM based on the plurality of pulse width modulation sub-signals.

[0132] For example, referring to FIG10 , taking the second ratio of the maximum value of the second brightness range to the highest display brightness as 50% as an example, the figure shows the waveforms of multiple initial pulse width modulation sub-signals corresponding to multiple bits (0 to n bits), as well as the initial pulse width modulation signal pwm' synthesized by the multiple initial pulse width modulation sub-signals.

[0133] The display brightness value is adjusted so that the ratio of the display brightness value to the maximum display brightness changes from 50% to 25%, and the rate of change of the display brightness value is 50%. In this case, the third ratio of the display brightness value to the maximum value of the second brightness range is 50%. The effective width of the initial pulse width modulation sub-signal is proportionally reduced by 50%, thereby generating multiple corresponding pulse width modulation sub-signals. The rate of change of the pulse width modulation sub-signals is also 50%. Furthermore, the pulse width modulation circuit 32 generates a pulse width modulation signal PWM based on the multiple pulse width modulation sub-signals. The effective width of the pulse width modulation signal PWM is reduced by 50% relative to the effective width of the initial pulse width modulation signal PWM', i.e., the rate of change of the pulse width modulation signal PWM is 50%.

[0134] It can be seen that when adjusting the display brightness value within the second brightness range, the larger the display brightness value, the larger the effective width of the pulse width modulation signal PWM, and the change rate of the effective width of the pulse width modulation signal is equal to the change rate of the display brightness value.

[0135] The dimming control method provided by the above embodiment of the present application adopts a hybrid dimming method to display the brightness signal V DBV The gamma correction circuit 31 and the pulse width modulation circuit 32 are input, and the gamma correction circuit 31 and the pulse width modulation circuit 32 respectively determine whether the display brightness value is within the first brightness range or the second brightness range.

[0136] When the display brightness value is within the first brightness range, i.e., the high brightness range, the gamma correction circuit 31 proportionally scales the grayscale of the data signal based on the ratio of the display brightness value to the maximum display brightness, generating a data correction signal. The pulse width modulation circuit 32 receives the data correction signal and outputs a corresponding pulse width modulation signal to control the duration of the drive current flowing through the pixel circuit 30, thereby adjusting the display brightness of the display device 1. Specifically, within the high brightness range, the display brightness of the display device 1 can be adjusted by proportionally scaling the grayscale of the data signal.

[0137] However, when the display brightness value is within the second brightness range, that is, within the low brightness range, continuing to perform proportional scaling mapping on the grayscale of the data signal according to the ratio of the display brightness value to the maximum display brightness will cause the grayscale accuracy of the data signal to be lost. For example, the grayscale of the data signal is 1, and after 50% proportional scaling mapping, the grayscale of the data correction signal is 0, which affects the display quality of the image.

[0138] Based on this, in the low brightness range, regardless of the display brightness value, the gamma correction circuit 31 proportionally scales the grayscale of the data signal according to the ratio of the maximum value in the second brightness range to the maximum display brightness, thereby generating a data correction signal. This can improve the problem of loss of grayscale accuracy of the data signal. The pulse width modulation circuit 32 receives the data correction signal and proportionally scales the effective width of the initial pulse width modulation signal according to the ratio of the display brightness value to the maximum value in the second brightness range, thereby generating a pulse width modulation signal. This is used to control the duration of the driving current flowing in the pixel circuit 30, thereby adjusting the display brightness of the display device 1.

[0139] It can be seen that the hybrid dimming method can improve the problem of grayscale accuracy loss at low brightness, and realize the adjustment of display brightness while ensuring the display quality of the display device 1.

[0140] Some embodiments of the present application also provide a dimming control circuit and a control method thereof. Figure 11 is a structural block diagram of another dimming control circuit provided by an embodiment of the present application; Figure 12 is a structural block diagram of yet another dimming control circuit provided by an embodiment of the present application; and Figure 13 is a flow chart of another dimming control method provided by an embodiment of the present application.

[0141] 11 , the display device 1 includes a dimming control circuit 3, which is configured to receive a display brightness signal V DBV , output drive current.

[0142] The dimming control circuit 3 is electrically connected to the light emitting chip 21 on the display panel 2, and the dimming control circuit 3 receives the display brightness signal V DBV and outputs the driving current to the light emitting chip 21 to drive the light emitting chip 21 to emit light.

[0143] In some embodiments, referring to FIG12 , the dimming control circuit 3 includes a gamma correction circuit 31, a pulse width modulation circuit 32, a pixel circuit 30, and a current control circuit 33. The gamma correction circuit 31, the pulse width modulation circuit 32, and the pixel circuit 30 are connected in sequence, and the current control circuit 33 is connected to the pixel circuit 30. The pixel circuit 30 is electrically connected to the light-emitting chip 21 on the display panel 2 to drive the light-emitting chip 21 to emit light.

[0144] Exemplarily, the pixel circuit 30 includes a current source I, and the current control circuit 33 is electrically connected to the current source I.

[0145] Exemplarily, the gamma correction circuit 31 , the pulse width modulation circuit 32 , the pixel circuit 30 and the current control circuit 33 may all be integrated into a same chip, which may be disposed on the display panel 2 .

[0146] Illustratively, the gamma correction circuit 31 , the pulse width modulation circuit 32 , the pixel circuit 30 and the current control circuit 33 are directly provided on the display panel 2 in the form of a film structure, which is conducive to making the display panel 2 lighter and thinner.

[0147] For example, the gamma correction circuit 31 may be provided on a circuit board of the display device 1. The pulse width modulation circuit 32, the pixel circuit 30 and the current control circuit 33 may be integrated into a chip, or directly provided on the display panel 2 in the form of a film structure.

[0148] The display brightness of the display device 1 has the 1st to nth brightness intervals that change from low to high, where n≥2. For example, the highest display brightness of the display device 1 is divided into n intervals, and the brightness of the n intervals changes from low to high.

[0149] 13 , the dimming control method includes the following steps S70 to S100 :

[0150] S70: The gamma correction circuit 31 receives the display brightness signal V DBV and data signal, outputs a data correction signal, the display brightness signal includes a display brightness value, according to the foregoing, the ratio of the display brightness value to the maximum display brightness is a "first ratio", and the ratio of the grayscale of the data correction signal to the grayscale of the data signal is a target ratio, which is greater than the first ratio.

[0151] FIG14 is another working principle diagram of the gamma correction circuit provided in an embodiment of the present application.

[0152] 14 , a gamma correction circuit 31 is used to adjust the grayscale of the data signal by scaling and mapping with a target ratio based on a gamma calibration algorithm, so as to adjust the display brightness of the display device 1 in subsequent method steps.

[0153] For example, when the first ratio is adjusted from 100% to 30%, if the target ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to 30%, the grayscale of the data signal is mapped by 30% to obtain the grayscale of the data correction signal, and the grayscale accuracy of the data signal is lost.

[0154] Based on this, by setting the target ratio of the grayscale of the data correction signal to the grayscale of the data signal to be greater than the first ratio, for example, when the first ratio is adjusted from 100% to 30%, the target ratio is set to 50%. After the reduction mapping, the number of grayscales is relatively large, therefore, the problem of loss of grayscale accuracy at low brightness can be improved.

[0155] It can be understood that the gamma correction circuit 31 stores a one-to-one correspondence between the display brightness value and the target ratio, that is, under different display brightnesses, the scaling ratio of the grayscale of the data correction signal and the grayscale of the data signal are not equal. Therefore, under the premise that the grayscale of the data signal is determined, the display brightness value can be adjusted to obtain different grayscales of the data correction signal to achieve display brightness adjustment.

[0156] Exemplarily, the display brightness value is proportional to the target ratio. That is, the larger the display brightness value, the larger the target ratio of the grayscale of the data correction signal to the grayscale of the data signal. Given a fixed grayscale of the data signal, the grayscale of the data correction signal is increased to increase the display brightness. Similarly, the smaller the display brightness value, the smaller the target ratio of the grayscale of the data correction signal to the grayscale of the data signal. Given a fixed grayscale of the data signal, the grayscale of the data correction signal is decreased to decrease the display brightness.

[0157] Based on this, the above S70 may include the following S701 to S702:

[0158] S701: The gamma correction circuit 31 receives the display brightness signal V DBV , according to the corresponding relationship, obtain the display brightness signal V DBV The target ratio corresponding to the display brightness value in .

[0159] S702: The gamma correction circuit 31 receives the data signal and outputs a data correction signal according to the target ratio.

[0160] It is understandable that the gamma correction circuit 31 adopts a scaling mapping method, uses a lookup table, and uses the product of the grayscale of the data signal and the target ratio as the lookup table address for table indexing, and the lookup table address corresponds to the data correction signal.

[0161] S80: The pulse width modulation circuit 32 receives the data correction signal and outputs a pulse width modulation signal.

[0162] It can be understood that the pulse width modulation circuit 32 receives the data correction signal, and generates and outputs a corresponding pulse width modulation signal according to the grayscale of the data correction signal.

[0163] S90: The current control circuit 33 receives the display brightness signal V DBV , output current control signal.

[0164] It can be understood that the current control circuit 33 stores a correspondence between each brightness interval and a driving current, and different brightness intervals correspond to different driving currents.

[0165] The magnitude of the drive current is positively correlated with i, where 1≤i≤n, and i is a positive number. For example, the first to nth brightness intervals correspond to the first to nth drive currents, and the first to nth drive currents change in sequence from low to high. That is, the larger the brightness interval value, the larger the corresponding drive current.

[0166] The current control circuit 33 receives the display brightness signal V DBV Afterwards, the current control circuit 33 determines the brightness interval in which the display brightness value is located. When the display brightness value is in the i-th brightness interval, the current control circuit 33 outputs the i-th current control signal corresponding to the i-th driving current.

[0167] S100 : the pixel circuit 30 receives the pulse width modulation signal and the i-th current control signal, and outputs the i-th driving current to control the display brightness of the display device 1 .

[0168] Illustratively, the pixel circuit 30 includes a current source I and a transistor M connected in series. The current source I receives the i-th current control signal and outputs the i-th drive current, which can adjust the magnitude of the drive current. The gate of the transistor M receives a pulse-width modulation signal. The pulse-width modulation signal controls the duration of the on / off state of the transistor M, thereby controlling the duration of the drive current flowing through the light-emitting chip 21.

[0169] The display brightness is proportional to the size of the driving current and the duration for which the driving current flows through the light-emitting chip 21. By adjusting the size of the driving current and the duration for which the driving current flows through the light-emitting chip 21, the display brightness of the display device 1 can be controlled.

[0170] In addition, the duration of the driving current is related to the effective width of the pulse width modulation signal, the effective width of the pulse width modulation signal is related to the gray scale of the data correction signal, and the gray scale of the data correction signal is related to the target ratio.

[0171] Therefore, during pre-shipment testing, the display brightness value of display device 1 is first divided into multiple brightness intervals that vary from low to high, and a corresponding relationship between the brightness intervals and the driving current is set. Based on the corresponding relationship between the brightness intervals and the driving current in the display brightness signal, the driving current in the pixel circuit is adjusted. Then, the data signal is input into the gamma correction circuit, and based on a first ratio of the display brightness value to the maximum display brightness, the grayscale of the data signal is scaled and mapped at a scaling ratio greater than the first ratio. The scaling ratio is continuously adjusted until the acquired brightness information of the display device matches the display brightness value, ultimately obtaining a corresponding relationship between the display brightness value and the target ratio.

[0172] The dimming control method provided by the above embodiment of the present application adopts a hybrid dimming method. The gamma correction circuit 31 receives the display brightness signal V DBV The data signal and the data signal are scaled and mapped using a target ratio greater than the first ratio to obtain a data correction signal. At lower brightness levels, the data signal's grayscale is scaled and mapped using a target ratio greater than the first ratio. This results in a wider grayscale range after scaling and mapping, thereby improving the problem of grayscale accuracy loss at low brightness levels. The pulse width modulation circuit 32 receives the data correction signal and outputs a pulse width modulation signal. The pixel circuit 30 receives the pulse width modulation signal to control the duration of the drive current.

[0173] Furthermore, the display brightness value of the display device 1 is divided into a plurality of brightness intervals that change from low to high. The plurality of brightness intervals correspond to a plurality of driving currents that change from low to high. That is, the larger the brightness interval, the larger the corresponding driving current. Based on this, the current control circuit 33 receives the display brightness signal V DBVAccording to the brightness range of the display brightness value and its corresponding driving current, the pixel circuit 30 outputs a current control signal corresponding to the driving current. The pixel circuit 30 receives the current control signal and outputs the corresponding driving current, thereby adjusting the magnitude of the driving current.

[0174] It can be seen that by adopting the above-mentioned hybrid dimming method, the size of the driving current and the duration of the driving current flowing through the light-emitting chip 21 can be adjusted respectively, thereby improving the problem of loss of grayscale accuracy at low brightness and realizing the adjustment of display brightness.

[0175] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A dimming control method, characterized in that: include: The dimming control circuit receives a display brightness signal and outputs a pulse width modulation signal; Wherein, the display brightness signal includes a display brightness value, and when the display brightness value is within a first brightness range, the effective width of the pulse width modulation signal does not change with the change of the display brightness value; when the display brightness value is within a second brightness range, the effective width of the pulse width modulation signal is positively correlated with the display brightness value; The minimum value of the first brightness range is greater than the maximum value of the second brightness range.

2. The control method according to claim 1, characterized in that: When the display brightness value is within the second brightness range, the change rate of the effective width of the pulse width modulation signal is equal to the change rate of the display brightness value.

3. The control method according to claim 1 or 2, characterized in that: The dimming control circuit includes a gamma correction circuit and a pulse width modulation circuit; The dimming control circuit receives a display brightness signal and outputs a pulse width modulation signal, including: The gamma correction circuit and the pulse width modulation circuit receive the display brightness signal respectively; In the case where the display brightness value is within the first brightness range, the gamma correction circuit receives a data signal and outputs a data correction signal, and the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the first ratio of the display brightness value to the highest display brightness; the pulse width modulation circuit receives the data correction signal and outputs the pulse width modulation signal; or, When the display brightness value is within the second brightness range, the gamma correction circuit receives a data signal and outputs a data correction signal, wherein a ratio of a grayscale of the data correction signal to a grayscale of the data signal is equal to a second ratio of a maximum value of the second brightness range to a maximum display brightness; the pulse width modulation circuit receives the data correction signal, generates an initial pulse width modulation signal, and outputs a pulse width modulation signal based on the initial pulse width modulation signal, wherein a ratio of an effective width of the pulse width modulation signal to an effective width of the initial pulse width modulation signal is equal to a third ratio of the display brightness value to the maximum value of the second brightness range.

4. The control method according to claim 3, characterized in that: After the gamma correction circuit receives the display brightness signal, it also includes: Determine whether the display brightness value is within the first brightness range or the second brightness range.

5. The control method according to claim 3 or 4, characterized in that: After the pulse width modulation circuit receives the display brightness signal, the circuit further includes: Determine whether the display brightness value is within the first brightness range or the second brightness range.

6. The control method according to any one of claims 3 to 5, characterized in that: The data correction signal includes a plurality of bits; When the display brightness value is within the second brightness range, the pulse width modulation circuit receives the data correction signal, generates an initial pulse width modulation signal, and outputs a pulse width modulation signal according to the initial pulse width modulation signal, including: The pulse width modulation circuit receives the data correction signal, generates a plurality of initial pulse width modulation sub-signals corresponding to the plurality of bits, generates a plurality of corresponding pulse width modulation sub-signals according to the plurality of initial pulse width modulation sub-signals, and obtains the pulse width modulation signal according to the plurality of pulse width modulation sub-signals; The ratio of the effective width of the pulse width modulation sub-signal to the effective width of the corresponding initial pulse width modulation sub-signal is equal to the third ratio.

7. A dimming control circuit, characterized in that: The dimming control circuit is configured to receive a display brightness signal and output a pulse width modulation signal; Wherein, the display brightness signal includes a display brightness value, and when the display brightness value is within a first brightness range, the effective width of the pulse width modulation signal does not change with the change of the display brightness value; when the display brightness value is within a second brightness range, the effective width of the pulse width modulation signal is positively correlated with the display brightness value; The minimum value of the first brightness range is greater than the maximum value of the second brightness range.

8. The dimming control circuit according to claim 7, characterized in that: The dimming control circuit includes a gamma correction circuit and a pulse width modulation circuit; The gamma correction circuit and the pulse width modulation circuit are both configured to receive the display brightness signal; The gamma correction circuit is further configured to, when the display brightness value is within the first brightness range, receive a data signal and output a data correction signal, wherein the ratio of the grayscale of the data correction signal to the grayscale of the data signal is equal to the first ratio of the display brightness value to the maximum display brightness; the pulse width modulation circuit is further configured to receive the data correction signal and output a pulse width modulation signal. signal; or, The gamma correction circuit is further configured to, when the display brightness value is within a second brightness range, receive a data signal and output a data correction signal, wherein a ratio of a grayscale of the data correction signal to a grayscale of the data signal is equal to a second ratio of a maximum value of the second brightness range to a maximum display brightness; the pulse width modulation circuit is further configured to receive the data correction signal, generate an initial pulse width modulation signal, and output a pulse width modulation signal based on the initial pulse width modulation signal, wherein a ratio of an effective width of the pulse width modulation signal to an effective width of the initial pulse width modulation signal is equal to a third ratio of the display brightness value to the maximum value of the second brightness range.

9. The dimming control circuit according to claim 8, characterized in that: The gamma correction circuit includes a first judgment subcircuit and a search subcircuit; The first judgment subcircuit is configured to receive the display brightness signal, judge whether the display brightness value is in the first brightness range or the second brightness range; if the display brightness value is in the first brightness range, output a first control signal including the first ratio; if the display brightness value is in the second brightness range, output a second control signal including the second ratio; The search subcircuit is electrically connected to the first judgment subcircuit, and is configured to receive the first control signal and the data signal, and output the data correction signal according to the first ratio and the grayscale of the data signal; or to receive the second control signal and the data signal, and output the data correction signal according to the second ratio and the grayscale of the data signal.

10. The dimming control circuit according to claim 8 or 9, characterized in that: The pulse width modulation circuit includes a second judgment subcircuit and a control subcircuit; The second judgment subcircuit is configured to receive the display brightness signal, judge whether the display brightness value is within the first brightness range or the second brightness range; if the display brightness value is within the second brightness range, output a third control signal including the third ratio; The control subcircuit is electrically connected to the second judgment subcircuit, and is configured to receive the third control signal and the data correction signal, generate the initial pulse width modulation signal according to the grayscale of the data correction signal, and output the pulse width modulation signal according to the third ratio and the effective width of the initial pulse width modulation signal.

11. A dimming control method, characterized in that: include: The dimming control circuit receives the display brightness signal and outputs a driving current; Wherein, the display brightness signal includes a display brightness value, and the brightness interval of the display brightness value corresponds to one of the driving currents; Different brightness ranges correspond to different driving currents.

12. The control method according to claim 11, characterized in that: The plurality of brightness intervals include a first brightness interval to an nth brightness interval that change sequentially from low to high, where n≥2; The magnitude of the driving current is positively correlated with i, 1≤i≤n, and i is a positive number.

13. The control method according to claim 11 or 12, characterized in that: The dimming control circuit includes a gamma correction circuit, a pulse width modulation circuit, a current control circuit and a pixel circuit; The dimming control circuit receives a display brightness signal and outputs a driving current, including: The gamma correction circuit receives the display brightness signal and the data signal, and outputs a data correction signal; the ratio of the grayscale of the data correction signal to the grayscale of the data signal is a target ratio, and the target ratio is greater than the ratio of the display brightness value to the maximum display brightness; The pulse width modulation circuit receives the data correction signal and outputs a pulse width modulation signal; The current control circuit receives the display brightness signal and outputs a current control signal; the first brightness interval to the nth brightness interval correspond to the first drive current to the nth drive current one by one, and the first drive current to the nth drive current change in sequence from low to high; when the display brightness value is in the i-th brightness interval, 1≤i≤n, the current control signal is the i-th current control signal corresponding to the i-th drive current; The pixel circuit receives the pulse width modulation signal and the i-th current control signal, and outputs the i-th driving current.

14. The control method according to claim 13, characterized in that: The gamma correction circuit stores a one-to-one correspondence between the display brightness value and the target ratio, and the display brightness value is positively correlated with the target ratio; The gamma correction circuit receives the display brightness signal and the data signal and outputs a data correction signal, including: The gamma correction circuit receives the display brightness signal, and acquires a target ratio corresponding to the display brightness value in the display brightness signal according to the corresponding relationship; The gamma correction circuit also receives the data signal and outputs the data correction signal according to the target ratio.

15. The control method according to claim 13 or 14, characterized in that: After the current control circuit receives the display brightness signal, it further includes: Determine the brightness interval in which the display brightness value lies.

16. A dimming control circuit, characterized in that: The dimming control circuit is configured to receive a display brightness signal and output a driving current; Wherein, the display brightness signal includes a display brightness value, and the brightness interval of the display brightness value corresponds to one of the driving currents; Different brightness ranges correspond to different driving currents.

17. The dimming control circuit according to claim 16, characterized in that: The dimming control circuit comprises: a gamma correction circuit configured to receive the display brightness signal and the data signal, and output a data correction signal; a ratio of a grayscale of the data correction signal to a grayscale of the data signal is a target ratio, and the target ratio is greater than a ratio of the display brightness value to a maximum display brightness; A pulse width modulation circuit is configured to receive the data correction signal and output a pulse width modulation signal; The current control circuit is configured to receive the display brightness signal and output a current control signal; the first brightness interval to the nth brightness interval correspond to the first drive current to the nth drive current one by one, and the first drive current to the nth drive current change in sequence from low to high; when the display brightness value is in the i-th brightness interval, 1≤i≤n, the current control signal is the i-th current control signal corresponding to the i-th drive current; The pixel circuit is configured to receive the pulse width modulation signal and the i-th current control signal, and output the i-th driving current.

18. The dimming control circuit according to claim 17, characterized in that: The pixel circuit includes a current source electrically connected to the current control circuit; The current source is configured to receive the i-th current control signal and output the i-th driving current.

19. A display device, characterized in that: include: A display panel including a plurality of light-emitting chips; The dimming control circuit according to any one of claims 7 to 10 and 16 to 18 is electrically connected to the light emitting chip.

Images