Brightness adjustment method and electronic device

Abstract

The present application provides a brightness adjustment method and an electronic device. In this method, for scenarios where the working mode of pixels in the screen changes before and after unlocking, the time frame between responding to the unlocking operation and displaying the interface after successful unlocking can be divided into a flashing frame time and a non-flashing frame time. In the flashing frame time, a grayscale value coefficient lower than the grayscale value coefficient 1 is used to lower the grayscale value of the pixels in the screen, and in the non-flashing frame time, a grayscale value coefficient 1 is used to lower the grayscale value of the pixels in the screen. By implementing the technical solution provided by the present application, for scenarios where the working mode of pixels in the screen changes before and after unlocking, the screen will not flash when unlocking, and the screen brightness can be kept consistent before and after unlocking.

Description

Technical Field

[0001] The present application relates to the field of terminals, and in particular to a brightness adjustment method and an electronic device. Background Art

[0002] At present, there are electronic devices that require fingerprint unlocking after the screen is locked before the user can enter the desktop of the electronic device. In response to the fingerprint unlocking operation, a part of the lock screen interface usually displays an unlocking special effect to prompt the user that the unlocking is in progress. For example, the unlocking special effect includes but is not limited to the fingerprint icon being lit up, animations being displayed around the fingerprint icon, etc.

[0003] The scene in which the electronic device displays the unlocking special effect when performing fingerprint unlocking can also be called the local highlight mode (LHBM) scene. In the LHBM scene, the electronic device can also control the brightness of the screen so that the screen brightness remains within an appropriate range.

[0004] How to reasonably control the screen brightness when unlocking with fingerprint is worth discussing. Summary of the invention

[0005] The present application provides a brightness adjustment method and an electronic device. For a scenario where the working mode of pixels in a screen changes before and after unlocking, the screen will not flash when unlocking, and the screen brightness can be kept consistent before and after unlocking.

[0006] In a first aspect, the present application provides a brightness adjustment method, the method comprising: at a first time, the electronic device displays a lock screen interface and controls the screen to work in a pulse width modulation (PWM) mode; in response to a user touching a fingerprint recognition area in the screen, the electronic device controls the screen to switch from working in the PWM mode to working in a direct current (DC) mode, and lowers the grayscale value of the pixels in the screen according to a first ratio in the first frame time after the switch, so as to control the screen brightness of the screen in the first frame time to be equal to or close to the first screen brightness; the first screen brightness is the screen brightness in the first time; in a second frame time, the electronic device lowers the grayscale value of the pixels in the screen according to a second ratio, so as to control the screen brightness of the screen in the second frame time to be equal to or close to the first screen brightness; the second ratio is higher than the first ratio, and the second frame time is the next frame time of the first frame time; the electronic device also collects a fingerprint after the switch, and if the collected fingerprint is consistent with the recorded fingerprint, after the second frame time, the electronic device displays an interface after successful unlocking.

[0007] In the above embodiment, the first time may be time A in the following embodiment. The first frame time may be frame time 1 in the embodiment. The first ratio is grayscale value coefficient A in the following embodiment, and the second ratio is grayscale value coefficient B in the following embodiment.

[0008] By implementing the above embodiment, in the scenario where the working mode of the pixels in the screen is switched before and after unlocking, the screen will not flicker when unlocking. The screen brightness can be kept consistent before and after unlocking, and it can be switched to DC mode, which is conducive to fingerprint unlocking.

[0009] In combination with the first aspect, in some embodiments, the method also includes: the electronic device displays a fingerprint spot image in the fingerprint recognition area, and the pixels used to display the fingerprint spot image have a first grayscale value, and the first grayscale value is higher than the average grayscale value of the pixels in the screen.

[0010] In the above embodiment, displaying the fingerprint spot image can illuminate the fingerprint recognition area, so as to illuminate the fingerprint of the user placed on the screen, so that the fingerprint collected by the fingerprint sensor below the fingerprint recognition area is clearer.

[0011] In combination with the first aspect, in some embodiments, lowering the grayscale values ​​of pixels in the screen according to a first ratio specifically includes: lowering the grayscale values ​​of pixels in an area of ​​the screen other than the fingerprint recognition area according to the first ratio; lowering the grayscale values ​​of pixels in the screen according to a second ratio specifically includes: lowering the grayscale values ​​of pixels in an area of ​​the screen other than the fingerprint recognition area according to the second ratio.

[0012] In the above embodiment, by not lowering the grayscale value of the pixels in the fingerprint recognition area, the pixels in the fingerprint recognition area can be brighter when displaying the fingerprint spot image, so as to illuminate the user's fingerprint on the screen and make the fingerprint collected by the fingerprint sensor below the fingerprint recognition area clearer.

[0013] In combination with the first aspect, in some embodiments, when the screen operates in the PWM mode, the screen brightness of the screen is below a first screen brightness, and the first screen brightness is the maximum screen brightness of the screen when operating in the PWM mode, and is the minimum screen brightness of the screen when operating in the DC mode.

[0014] In the above embodiment, the first screen brightness may be the preset brightness in the embodiment.

[0015] In combination with the first aspect, in some embodiments, when the screen operates in the DC mode, the screen brightness of the screen is above a first screen brightness, and the first screen brightness is the minimum screen brightness of the screen operating in the DC mode.

[0016] In combination with the first aspect, in some embodiments, the method also includes: in response to the unlocking operation, before the electronic device lowers the grayscale value of the pixels in the screen according to the first ratio, the electronic device controls the display subsystem to power on; the display subsystem is used to control the screen driver chip to lower the grayscale value of the pixels in the screen according to the first ratio or the second ratio; after the display subsystem controls the screen driver chip to lower the grayscale value of the pixels in the screen according to the second ratio, the electronic device controls the display subsystem to power off; wherein, between the time when the display subsystem is powered on and the time when the screen driver chip is controlled to lower the grayscale value of the pixels in the screen according to the second ratio, the display subsystem remains powered on.

[0017] In the above embodiment, the display subsystem is controlled to be powered off only after the grayscale of the pixels on the screen is lowered. This ensures that the instructions for lowering the grayscale of the pixels on the screen in the second frame time can be issued in the first frame time, so that the grayscale of the pixels on the screen can be lowered using the second ratio in the second frame time.

[0018] In combination with the first aspect, in some embodiments, after the electronic device controls the display subsystem to power on, the method also includes: the electronic device sends a first instruction to the screen display chip through the display subsystem, and the first instruction carries the first ratio; after the screen display chip receives the first instruction, the grayscale value of the pixel in the screen is reduced based on the first ratio.

[0019] In combination with the first aspect, in some embodiments, after the grayscale values ​​of pixels in the screen are lowered according to the first ratio, when the screen displays the first image in the first frame time, the method also includes: the electronic device sends a second instruction to the screen display chip through the display subsystem, and the second instruction carries the second ratio; after the screen display chip receives the second instruction, the grayscale values ​​of pixels in the screen are lowered based on the second ratio when the second frame time is reached.

[0020] In the above embodiment, the first instruction may be code1 in the embodiment, and the second instruction may be code2 in the embodiment. The display subsystem is controlled to be powered off only after code2 is sent, so that code2 can be sent to DDIC within one frame time.

[0021] In combination with the first aspect, in some embodiments, the electronic device controls the display subsystem to power on, specifically including: the electronic device calls a power management interface in a display driver to control the display subsystem to power on.

[0022] In combination with the first aspect, in some embodiments, the method further includes: when a first preset time has passed since the display subsystem sent the second instruction to the screen display chip, the electronic device calls the power management interface to control power off of the display subsystem.

[0023] In combination with the first aspect, in some embodiments, the method further includes: after the first time, before the electronic device controls the display subsystem to be powered on, the system-on-chip chip of the electronic device is in an idle state, and the display subsystem is powered off by a sleep mechanism. The sleep mechanism corresponds to a wake-up mechanism, and the wake-up mechanism is used to wake up the system-on-chip chip in response to a wake-up operation when the system-on-chip chip is idle; when the system-on-chip chip is awakened, the display subsystem is powered on, and the idle state of the system-on-chip chip includes the state of the system-on-chip chip when the screen is in sleep mode, and the wake-up operation does not include an unlocking operation.

[0024] In combination with the first aspect, in some embodiments, before lowering the grayscale value of the pixels in the screen according to the first ratio, the method further includes: the electronic device detecting that the electronic device is in a dark light environment.

[0025] In the above embodiment, in a dark environment, the user can easily perceive the flickering of the first frame, so it is necessary to use the first ratio to lower the screen grayscale in the first frame to prevent the flickering of the first frame.

[0026] In combination with the first aspect, in some embodiments, the screen is an organic light emitting diode (OLED) screen.

[0027] In combination with the first aspect, in some embodiments, the method also includes: after lowering the grayscale value of the pixels in the screen according to the first ratio, controlling the screen to display a first image in the first frame time, the first image being the first frame displayed after the first time and including an image of indication information, the indication information being used to indicate that the electronic device is being unlocked; the indication information includes at least the fingerprint spot image; after lowering the grayscale value of the pixels in the screen according to the second ratio, the screen displays a second image in a second frame time, the second image also including the indication information.

[0028] In combination with the first aspect, in some embodiments, controlling the screen to display the first image in the first frame time specifically includes: the electronic device determines the first turn-on voltage corresponding to the first pixel on the display channel through the first color correction curve and the grayscale value of the first pixel in the screen; wherein the first color correction curve is a color correction curve corresponding to the preset brightness in a group of color correction curves associated with the second screen refresh rate; the first pixel is a pixel in the screen whose grayscale value is reduced based on the second ratio, and the first pixel is used to display the content of the first image other than the fingerprint spot image; the second screen refresh rate is the screen refresh rate of the screen when displaying the first image; the electronic device determines the second turn-on voltage corresponding to the second pixel on the display channel through the first grayscale value; the second pixel is used to display the content in the fingerprint spot image; controlling the turn-on voltage of the first pixel on the display channel to be the first turn-on voltage, and controlling the turn-on voltage of the second pixel on the display channel to be the second turn-on voltage, the first pixel after being turned on displays the pixel corresponding to the first pixel in the first image, and the second pixel after being turned on displays the pixel corresponding to the second pixel in the first image.

[0029] In a second aspect, the present application provides a brightness adjustment method, the method comprising: at a first time, the electronic device displays a lock screen interface and controls the screen to work in a pulse width modulation (PWM) mode; in response to a user touching a fingerprint recognition area in the screen, the electronic device controls the screen to switch from working in the PWM mode to working in a direct current (DC) mode, and in a first frame time after the switch, lowers the grayscale value of the pixels in the screen according to a first ratio, so as to control the screen brightness of the screen in the first frame time to be equal to or close to the screen brightness of the first time; in a second frame time, the electronic device lowers the grayscale value of the pixels in the screen according to a second ratio, so as to control the brightness of the screen in the second frame time to be equal to or close to the screen brightness of the first time; the second ratio is higher than the first ratio, and the second frame time is the next frame time of the last frame time in the first frame time; the electronic device also collects a fingerprint after the switch, and if the collected fingerprint is consistent with the recorded fingerprint, after the second frame time, the electronic device displays an interface after successful unlocking.

[0030] In combination with the second aspect, in some embodiments, the method also includes: before the grayscale value of the pixels in the screen is lowered according to the first ratio, the electronic device controls the display subsystem to power on; the display subsystem is used to control the screen driver chip to lower the grayscale value of the pixels in the screen according to the first ratio or the second ratio; after the display subsystem controls the screen driver chip to lower the grayscale value of the pixels in the screen according to the second ratio, the electronic device controls the display subsystem to power off; wherein, between the time when the display subsystem is powered on and the time when the screen driver chip is controlled to lower the grayscale value of the pixels in the screen according to the second ratio, the display subsystem remains powered on.

[0031] In combination with the second aspect, in some embodiments, after the electronic device controls the display subsystem to power on, the method also includes: the electronic device sends a first instruction to the screen display chip through the display subsystem, and the first instruction carries the first ratio; after the screen display chip receives the first instruction, the grayscale value of the pixel in the screen is reduced based on the first ratio.

[0032] In combination with the second aspect, in some embodiments, after the grayscale values ​​of pixels in the screen are lowered according to the first ratio, in the last frame time of the first frame time, the method also includes: the electronic device sends a second instruction to the screen display chip through the display subsystem, and the second instruction carries the second ratio; after the screen display chip receives the second instruction, the grayscale values ​​of pixels in the screen are lowered based on the second ratio when the second frame time is reached.

[0033] In a third aspect, an embodiment of the present application provides an electronic device, comprising: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the electronic device to execute the method implemented in the first aspect.

[0034] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, comprising instructions, which, when executed on an electronic device, enable the electronic device to execute the method implemented in the first aspect.

[0035] In a fifth aspect, an embodiment of the present application provides a chip system, which is applied to an electronic device. The chip system includes one or more processors, and the processor is used to call computer instructions so that the electronic device executes the method implemented in the first aspect.

[0036] In a sixth aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on an electronic device, enables the electronic device to execute the method implemented in the first aspect.

[0037] It can be understood that the brightness adjustment method provided in the second aspect, the electronic device provided in the third aspect, the computer storage medium provided in the fourth aspect, the chip system provided in the fifth aspect, and the computer program product provided in the sixth aspect are all used to execute the method provided in the embodiment of the present application. Therefore, other beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 An exemplary user interface showing a flashing frame during fingerprint unlocking is shown;

[0039] Figure 2 An exemplary user interface is shown in which the screen does not flash during fingerprint unlocking;

[0040] Figure 3A A schematic diagram showing a scenario in which the display subsystem correctly downloads code2 to the display driver chip;

[0041] Figure 3B A schematic diagram showing the screen brightness in a scene with correct code 2 is shown;

[0042] Figure 4A A schematic diagram showing a scenario in which the display subsystem erroneously sends code 2 to the display driver chip;

[0043] Figure 4B A schematic diagram showing screen brightness in the scene with error code 2 is shown;

[0044] Figure 5 is an exemplary software and hardware structure block diagram of the brightness adjustment method in this application;

[0045] Fig. 6A as well as Figure 6B Describe the module interaction process involved in code method 1 and the effect diagram involved in code method 1;

[0046] Fig. 7A as well as Figure 7B Describe the module interaction process involved in code method 2 and the effect diagram involved in code method 2;

[0047] Fig. 8A as well as Figure 8B Describe the module interaction process involved in code method 3 and the effect diagram involved in code method 3;

[0048] Fig. 9 The diagram of the module interactions involved in the method of powering up the display subsystem in advance before downloading the code is shown;

[0049] Fig.10 An exemplary diagram of a gamma curve is shown;

[0050] Fig.11 A schematic diagram showing the adjustment of the grayscale value and the display image based on the target gamma curve is shown;

[0051] Fig.12 The figure shows the corresponding relationship between grayscale value and brightness under different gamma curves;

[0052] Fig.13 A schematic diagram showing the corresponding relationship between display brightness value and screen brightness;

[0053] Fig.14 An exemplary flow chart of a brightness adjustment method is shown;

[0054] Fig.15 A diagram showing the working principle of pixels in the screen;

[0055] Fig.16 It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In a scheme for adjusting screen brightness, at time 1, the electronic device displays the lock screen interface. In response to the fingerprint unlocking operation, the electronic device will display unlocking prompt information (such as unlocking special effects) to prompt the user that the unlocking is in progress. Between time 1 and the display of the unlocking success interface, it is more reasonable for the electronic device to keep the screen brightness unchanged.

[0057] If the screen brightness at time 1 is low, lower than the preset brightness, the working mode of the pixels in the screen is pulse width modulation (PWM) mode. If unlocking is to be performed more smoothly, it is usually necessary to switch the working mode of the pixels in the screen from PWM mode to direct current (DC) mode.

[0058] The reasons why switching to DC mode is more conducive to fingerprint unlocking include: In PWM mode, the pixels in the screen do not continuously emit light in one frame time, so that the screen brightness is lower. The non-luminescence of the pixels in the screen means that the pixels are not turned on, and the screen is actually in a black screen state, but the time when the pixels in the screen are not turned on in PWM mode is extremely short and the user does not notice it. In the black screen state, the pixels in the screen of the electronic device are not turned on, and the fingerprint cannot be imaged on the screen, so the fingerprint cannot be collected. In DC mode, the pixels in the screen continuously emit light in one frame time, which can better perform the fingerprint unlocking operation: performing the fingerprint unlocking operation requires collecting the fingerprint when the pixels in the screen are turned on.

[0059] In the following text, for the convenience of description, fingerprint unlocking is referred to as unlocking.

[0060] However, compared to time 1, when displaying the prompt information, the working mode of the pixels in the screen is switched from PWM mode to DC mode by increasing the display brightness value (DBV) of the screen. Increasing the DBV of the screen will increase the backlight brightness of the screen, which will in turn make the screen brighter (for specific reasons, please refer to the following Fig.11 as well as Fig.15 ). Therefore, the preset brightness mentioned above can be understood as the brightness converted from the minimum display brightness (recorded as display brightness value A) when the working mode of the pixel in the screen is the direct current mode. It can also be understood that when the display brightness value of the screen is greater than or equal to the display brightness value A, the screen brightness of the screen is correspondingly greater than or equal to the preset brightness. At this time, the working mode of the pixel in the screen (the working module of the screen) is the DC mode. When the display brightness value of the screen is less than the display brightness value A, the screen brightness of the screen is correspondingly less than the preset brightness. At this time, the working mode of the pixel in the screen (the working module of the screen) is the PWM mode.

[0061] Therefore, when the working mode is switched from PWM mode to DC mode, in order to keep the screen brightness unchanged from time 1 to the interface showing successful unlocking, it is necessary to reduce the grayscale value of the pixels in the screen to offset the screen brightening effect caused by increasing the DBV of the screen, so that the screen brightness remains unchanged. It should be noted here that the grayscale value of the pixels in the screen corresponds to the on-voltage of a pixel, and the pixel turns on and illuminates after the on-voltage is input to the pixel. Reducing the grayscale value of the pixels in the screen means that the on-voltage becomes lower, and then the brightness level of the pixel display is reduced so that the screen brightness can be dimmed. For a detailed description of this, please refer to the following Fig.11 as well as Fig.15 The description of is not repeated here.

[0062] In this brightness adjustment method, after time 1, although the electronic device reduces the grayscale value of the pixel in the screen after time 1, the same grayscale value coefficient (grayscale value coefficient 1) is used to reduce the grayscale value of the pixel in the screen in different time frames. Because the pixels in the screen will have a response lag when the working mode is switched, the screen will appear flickering. The flickering caused by the hysteresis response includes: the brightness of the pixel when it is turned on cannot change accordingly with the change of the on-voltage (related to the grayscale value), which is usually manifested as even if the input on-voltage becomes lower, the pixel still cannot respond to the lowered on-voltage during the hysteresis response, and is still affected by the on-voltage before the lowering, resulting in the brightness of the pixel being higher than the normal response to the lowered on-voltage, so the screen will appear flickering during the hysteresis response. This response lag phenomenon will gradually disappear over time, and the time of this response lag is very short, only a few frames, recorded as X frames. X is an integer greater than or equal to 1, usually one frame time. Among them, one frame time is the reciprocal of the screen refresh rate, which can also be understood as the time for a frame of image to be displayed continuously. For example, when the screen refresh rate is 60HZ (Hertz), the time for one frame is 1 / 60s.

[0063] Here, the X frame time during which the delayed response occurs is called the flash frame time. The screen flash occurs during the flash frame time. If X frames is equal to 1, the screen flash phenomenon of the electronic device during the flash frame time can be called the first frame flash. The first frame here is the first frame time after the working mode of the pixels in the screen is switched from PWM mode to DC mode after time 1.

[0064] In summary, the screen flashes in response to the unlocking operation because: the screen brightness at time 1 is equal to or close to the screen brightness when the response is normal after time 1. However, during the flashing frame time, the grayscale value of the pixels in the screen is still lowered according to the grayscale value coefficient 1, which cannot offset the screen brightening effect caused by increasing the DBV (switching working mode) of the screen, resulting in a screen brightness higher than time 1 and higher than the screen brightness when the response is normal.

[0065] Figure 1 An exemplary user interface showing a flashing frame during fingerprint unlocking is shown.

[0066] like Figure 1 The screen shown in (1) can be regarded as the screen corresponding to time 1, at which the screen brightness is relatively dim, less than the preset brightness. In response to an operation on the fingerprint icon 101 (e.g., a click operation), the electronic device increases the DBV of the screen and lowers the grayscale value of the pixels in the screen by a grayscale value coefficient of 1 to ensure that the fingerprint is collected smoothly and the screen brightness remains unchanged as much as possible. However, if Figure 1As shown in (2), during the flash frame time, lowering the grayscale value of the pixels in the screen according to the grayscale value coefficient 1 cannot offset the screen brightening effect caused by increasing the DBV (switching working mode) of the screen, and a screen brightening user interface appears. Figure 1 As shown in (3), the response lag of the pixels in the screen due to the switching of the working mode disappears, and lowering the grayscale value of the pixels in the screen according to the grayscale value coefficient 1 can offset the screen brightening effect caused by increasing the DBV of the screen (switching the working mode). Therefore, Figure 1 The screen brightness of the screen shown in (3) is Figure 1 (1) shows that the screen brightness of the screens is equal or close.

[0067] Refer to Figure 1 (2) and Figure 1 In (3), in response to the unlocking operation, the electronic device may also display unlocking prompt information (including prompt information 102 and prompt information 103) around the fingerprint icon 101 to prompt the user that the electronic device is being unlocked.

[0068] In some possible cases, the prompt information 102 and the prompt information 103 usually include dynamic special effects. For example, the prompt information 102 can be a light spot that lights up in the area where the fingerprint icon is located. The prompt information 103 can be water ripples around the fingerprint icon, and the shape of the water ripples will change over time.

[0069] It should be noted that in order to better display dynamic special effects, in response to the unlocking operation, when the DBV of the screen is increased and the grayscale value of the pixels in the screen is decreased, the screen refresh rate of the screen needs to be maintained at a high level. If the screen refresh rate at time 1 is less than the preset refresh rate, the screen refresh rate of the screen will be increased to the preset refresh rate in response to the unlocking operation.

[0070] In order to solve the problem of screen flickering when the electronic device responds to the fingerprint unlocking operation in the aforementioned solution, a brightness adjustment method is proposed. In this method, for the aforementioned problem scenario, the time frame between responding to the unlocking operation and displaying the interface after the successful unlocking can be divided into flickering frame time and non-flashing frame time (the time after the flickering frame time). During the flickering frame time, a grayscale value coefficient lower than the grayscale value coefficient 1 is used to lower the grayscale value of the pixels in the screen, and during the non-flashing frame time, a grayscale value coefficient 1 is used to lower the grayscale value of the pixels in the screen. This ensures that the screen brightness of the electronic device remains unchanged between time 1 and the interface after the successful unlocking. Figure 2 Zhong (1) and Figure 2 As shown in (2), in response to an operation (such as a click operation) on the fingerprint icon 101, the screen of the electronic device does not flash while the unlock prompt information (including prompt information 102 and prompt information 103) is displayed.

[0071] Specifically, at time A, the electronic device displays the lock screen interface and controls the screen to work in pulse width modulation (PWM) mode. In response to the unlocking operation, the electronic device controls the screen to switch from working in PWM mode to working in direct current (DC) mode, and adjusts the grayscale value of the pixels in the screen down according to the grayscale value coefficient A (less than the grayscale value coefficient 1) during the flashing frame time, so as to control the brightness of the screen during the flashing frame time to be equal to or close to the screen brightness during time A. In the last frame time of the flashing frame time, the electronic device needs to switch the coefficient for adjusting the grayscale value of the screen down from the grayscale value coefficient A to the grayscale value coefficient B (equal to the grayscale value coefficient 1), and then when entering the first frame of the non-flashing frame time, the grayscale value of the pixels in the screen can be adjusted down according to the grayscale value coefficient B, so as to control the screen brightness during the first frame time of the non-flashing frame time to be equal to or close to the screen brightness during time A. Subsequently, the electronic device can continue to use the grayscale value coefficient B to adjust the grayscale value of the pixels in the screen down to control the screen brightness during the subsequent frame time to be equal to or close to the screen brightness during time A.

[0072] The electronic device also collects fingerprints after the screen switches to working in DC mode. If the collected fingerprint is consistent with the recorded fingerprint, the electronic device displays the interface after successful unlocking.

[0073] Since it takes a certain amount of time to collect fingerprints and perform fingerprint comparison, usually, the electronic device can complete the unlocking and display the interface after the successful unlocking after entering the first frame of the non-flashing frame time.

[0074] The unlocking operation may be an operation in which the user touches a fingerprint recognition area within the screen, where the fingerprint recognition area is the area where the fingerprint icon is located.

[0075] In some possible cases, when collecting fingerprints, the electronic device also displays a light spot (also called a fingerprint light spot image or fingerprint light spot) in the fingerprint recognition area, and the grayscale value of the pixel used to display the light spot is higher, usually higher than the average grayscale value of the pixels in the screen. For example, the grayscale value of the pixel used to display the light spot can be a value between 230-255. In this way, the light spot can illuminate the fingerprint recognition area, making it easier to illuminate the user's fingerprint on the screen, so that the fingerprint collected by the fingerprint sensor below the fingerprint recognition area is clearer.

[0076] When the fingerprint spot is displayed in the fingerprint recognition area, lowering the grayscale value of the pixel in the screen according to the grayscale value coefficient A during the flashing frame time includes: lowering the grayscale value of the pixel in the area other than the fingerprint recognition area in the screen according to the grayscale value coefficient A. When the fingerprint spot is displayed in the fingerprint recognition area, lowering the grayscale value of the pixel in the screen according to the grayscale value coefficient B includes: lowering the grayscale value of the pixel in the area other than the fingerprint recognition area in the screen according to the grayscale value coefficient B.

[0077] It should be noted that when the screen works in PWM mode, the screen brightness of the screen is less than the preset brightness. When the screen works in DC mode, the screen brightness of the screen is greater than or equal to the preset brightness. Therefore, the execution condition of the aforementioned electronic device lowering the grayscale value of the pixels in the screen according to the grayscale value coefficient A (less than the grayscale value coefficient 1) during the flashing frame time can also be understood as: when the screen brightness at time A is less than the preset brightness, the grayscale value of the pixels in the screen is lowered according to the grayscale value coefficient A (less than the grayscale value coefficient 1) during the flashing frame time.

[0078] The instruction (code) to lower the grayscale value of the pixels on the screen according to the grayscale value coefficient B is generated by the software side (such as the display driver) and needs to be sent to the hardware side (such as the display driver chip) to take effect, so that the display driver chip can lower the grayscale value of the pixels on the screen according to the grayscale value coefficient B based on the instruction. The operation of sending this instruction to the display driver chip needs to be completed in the last frame time of the flashing frame time. If it is sent too early, the grayscale value of the screen will be adjusted in advance using the grayscale value coefficient B before the flashing frame time ends, and the screen will flash after the adjustment. If it is sent too late, the grayscale value of the pixels on the screen will still be adjusted according to the grayscale value coefficient A when entering the first frame of the non-flashing frame time, causing the screen to darken.

[0079] However, the last frame time of the flashing frame time is very short. How to complete the issuance of instructions in the last frame time of the flashing frame time is the key to solving the screen flashing problem. The implementation of this process can refer to the following Fig. 7A , Figure 7B , Fig. 8A , Figure 8B The description of the related contents will not be elaborated here.

[0080] The brightness adjustment method is described below by taking the flashing frame time as an example. That is, the last frame time of the flashing frame time is the flashing frame time itself, and the first frame time in the flashing frame time is also the flashing frame itself. For the convenience of description, the flashing frame time is called frame time 1, and the first frame time of the non-flashing frame time is called frame time 2, where frame time 2 is the next frame time of frame time 1.

[0081] It should be noted here that the instructions received by the display driver chip (display driver IC, DDIC) for adjusting the grayscale value of the pixels in the screen can come from the mobile display subsystem (mobile display subsystem, MDSS) (referred to as the display subsystem). In this brightness adjustment method, the instructions sent by the display driver chip to the display subsystem are in addition to the aforementioned instructions for lowering the grayscale value of the pixels in the screen according to the grayscale value coefficient B. There is also an instruction to lower the grayscale value of the pixels in the screen according to the grayscale value coefficient A. After the instruction to lower the grayscale value of the pixels in the screen based on the grayscale value coefficient A (also referred to as code1) is issued, the instruction to lower the grayscale value of the pixels in the screen based on the grayscale value coefficient B (also referred to as code2) will be issued. And code2 needs to be issued within frame time 1. Figure 3A FIG. 4 shows a scenario in which the display subsystem correctly downloads code 2 to the display driver chip.

[0082] refer to Figure 3A At time A, the electronic device displays the lock screen interface. In response to the unlocking operation, the display subsystem (MDSS) of the electronic device sends code1 to the display driver chip (DDIC). After time A and before frame time 1, the display driver chip (DDIC) receives code1, which can also be understood as the display subsystem completing code1. The first frame in which code1 takes effect can be regarded as frame time 1. At frame time 1, the display driver chip lowers the grayscale value of the pixels in the screen through the grayscale value coefficient A carried in code1, so that the screen brightness at frame time 1 is equal to or close to the screen brightness at time A (screen brightness A).

[0083] At frame time 1, the display subsystem completes code 2 (which can also be understood as the display driver chip receiving code 2). At frame time 2, code 2 takes effect: the display driver chip lowers the grayscale value of the pixels on the screen through the grayscale value coefficient B carried in code 2, so that the screen brightness at frame time 1 is still equal to or close to the screen brightness A. At the frame time after frame time 2 (for example, frame time 3), the display driver chip does not receive a new code and will continue to use the grayscale value coefficient B to lower the grayscale value of the pixels on the screen to keep the screen brightness equal to or close to the screen brightness A.

[0084] refer to Figure 3B , for Figure 3A In the scenario where code2 is correctly downloaded, the screen brightness is measured using a photoelectric sensor. It can be seen that at time A, the screen brightness is screen brightness A. After responding to the unlock operation, the screen brightness is still equal to or close to screen brightness A.

[0085] contrast Figure 3A , Figure 4AA schematic diagram showing the screen becoming dark or still flashing in the scenario of error code 2.

[0086] Figure 4A (1) shows the situation where the screen becomes dark when code2 is sent too late. In this case, code1 takes effect at frame time 1 after the display subsystem completes code1. However, the display subsystem completes code2 at frame time 2, causing code1 to continue to take effect at frame time 2 after it takes effect at frame time 1. Code2 does not take effect at frame time 2, but takes effect at frame time 3. Therefore, at frame time 2, the display driver chip (DDIC) still adjusts the grayscale value of the pixels in the screen according to the grayscale value coefficient A, causing the screen to become dark. That is, at frame time 2, the screen brightness (screen brightness B) is less than the screen brightness A.

[0087] refer to Figure 4B In (1), Figure 4B In (1), when code2 is sent too late, the screen brightness is measured using a photoelectric sensor. It can be seen that at time A, the screen brightness is screen brightness A. After responding to the unlock operation, the screen brightness decreases at frame time 2.

[0088] Figure 4A (2) shows the situation where the screen becomes brighter when code2 is sent too early. In this situation, the display subsystem completes code1 and code2 in the same frame time. Code1 has not yet taken effect, but code2 overwrites code1. At frame time 1, code2 takes effect, and the display driver chip (DDIC) adjusts the grayscale value of the pixels in the screen according to the grayscale value coefficient A, causing the screen to flicker. That is, at frame time 1, the screen brightness (screen brightness C) is greater than the screen brightness A.

[0089] refer to Figure 4B In (2), Figure 4B In (2), when code2 is sent too early, the screen brightness is measured using a photoelectric sensor. It can be seen that at time A, the screen brightness is screen brightness A. After responding to the unlock operation, the screen brightness increases at frame time 2.

[0090] It should be noted here that Figure 3A as well as Figure 4A TE vsync refers to the vertical synchronization signal of the display (vertical sync), which is used to control the screen refresh image.

[0091] It should be noted here that when the screen is locked, the screen is in a dormant (idle) state, and the system-on-a-chip (SOC) of the electronic device is in an idle state. In order to save power, when the screen is locked, the electronic device will enable the dormant mechanism to control some hardware to power off, and the hardware that is powered off includes the display subsystem. Although the dormant mechanism corresponds to the early wake-up mechanism (referred to as the wake-up mechanism), which is used to respond to the wake-up operation when the system-on-chip chip is idle, and wake up the system-on-chip chip during screen dormancy (the display subsystem will also be powered on when the system-on-chip chip is awakened), the wake-up operation specified in the wake-up mechanism does not include the unlocking operation.

[0092] From the above, it can be seen that when unlocking, if there is no wake-up operation, the display subsystem will be in a power-off state. Then if the display subsystem needs to send instructions (including code1 and code2) to the display driver chip, the display driver chip needs to be powered on first. In order to save power, when the screen is locked, the working characteristics of the display subsystem include: the display subsystem is powered on first to complete the issuance of an instruction (such as code1), and then it will be powered off. Then it will be powered on again to complete the issuance of another instruction (such as code2). The issuance here includes: sending instructions to the display driver chip.

[0093] Combined with the above sleep mechanism and the working characteristics of the display driver chip when the screen is locked, three ways of controlling the display subsystem to download code to the display driver chip are provided.

[0094] Code download method 1: In this method, the software side (such as the display driver) first downloads code 1 to the display driver chip through the display subsystem. Wherein, code 1 download includes: the software side (such as the display driver) first controls the usage count corresponding to the display subsystem to +1 (from 0 to 1). When the display subsystem is in the power-on state, the display subsystem is notified to send code 1 to the display driver chip, and then the usage count corresponding to the display subsystem is controlled to -1 (from 1 to 0). The usage count -1 is determined by the working characteristics of the display subsystem when the screen is locked: the usage count corresponding to the display subsystem is +1 in order to execute an instruction, and after the instruction is executed, the usage count should be -1. The original intention is to control the display subsystem to be powered off after completing an instruction and enter the power-off state to achieve power saving.

[0095] When code 1 is downloaded in code mode 1, the purpose of controlling the usage count corresponding to the display subsystem to +1 is to ensure that the display subsystem can be powered on and is in a powered-on state. Because when the screen is locked, the display subsystem is in a powered-off state due to the sleep mechanism. If the wake-up operation specified in the wake-up mechanism is not detected, the display subsystem will remain in a powered-off state. In the powered-off state, the usage count corresponding to the display subsystem is equal to 0. Only when the usage count jumps from 0 to 1 will the display subsystem be triggered to power on.

[0096] Combining the purpose of using the count +1 mentioned above, it can be concluded that when the screen is locked, if the wake-up operation specified in the wake-up mechanism is not detected, then executing the use count -1 can control the display subsystem to switch from the power-on state to the power-off state.

[0097] After completing the download of code1, the software side (such as the display driver) downloads code2 to the display driver chip through the display subsystem. Wherein, downloading code2 includes: at frame time 1, the software side (such as the display driver) controls the usage count corresponding to the display subsystem to be +1 (from 0 to 1). When the display subsystem is in the power-on state, the display subsystem sends code2 to the display driver chip, and then controls the usage count corresponding to the display subsystem to be -1 (from 1 to 0). Here, the functions of the usage count +1 and the usage count -1 are respectively the same as the functions of the usage count +1 and the usage count -1 when the aforementioned code1 is sent, and will not be repeated here.

[0098] It should be noted here that when the usage count corresponding to the display subsystem increases from 0 to 1, it does not mean that the display subsystem has been powered on, but it can trigger the display driver to call the power management interface to power on the display subsystem so that the display subsystem is in a powered-on state. When the usage count corresponding to the display subsystem decreases from 1 to 0, it does not mean that the display subsystem has been powered off, but it can trigger the display driver to call the power management interface to power off the display subsystem so that the display subsystem is in a powered-off state.

[0099] For details about the code method 1, please refer to the following Fig. 6A as well as Figure 6B The description of is not repeated here.

[0100] However, in the code downloading method 1, the usage count -1 executed after code1 is sent to the display driver chip will cause the display subsystem to power off. Therefore, before sending code2, the display subsystem needs to be powered on again, and only after entering the power-on state can code2 be downloaded to the display driver chip. The power-on process will take some time and occurs within frame time 1. Frame time 1 is relatively short, and it is possible that code2 fails to be downloaded during frame time 1. The failure to download code2 here means that code2 is not transmitted to the display driver chip during frame time 1, resulting in frame time 2 still using the grayscale value coefficient A carried in code1 to adjust the grayscale value of the pixels on the screen, causing the screen to dim during frame time 2. For scenarios where the screen dims during frame time 2, please refer to the aforementioned Figure 4A (1) and Figure 4B Description of (1) and its related contents.

[0101] In order to solve the problem that code2 may fail to be downloaded in frame time 1 due to power-on again in code download mode 1, code download mode 2 is proposed. In code download mode 2, after the electronic device sends code1 to the display driver chip, although the use count -1 is executed, the display subsystem is not powered off, and the display subsystem is still powered on. In frame time 1, the display subsystem does not need to be powered on again, which shortens the time to complete code2. Code2 can be completed in frame time 1. For details about code download mode 2, please refer to the following description.

[0102] Method 2 for downloading code: In this method, before the aforementioned code1 is downloaded to the display driver chip through the display subsystem, the software side (such as the display driver) will use the wake-up mechanism to first control the usage count corresponding to the display subsystem +1, so that the usage count changes from 0 to 1, and the display subsystem switches from the power-off state to the power-on state. Subsequently, the software side (such as the display driver) downloads code1 through the display subsystem: the software side (such as the display driver) controls the usage count corresponding to the display subsystem to +1 again (from 1 to 2). When the display subsystem is in the power-on state, the display subsystem is notified to send code1 to the display driver chip, and then the usage count corresponding to the display subsystem is controlled -1 (from 2 to 1). After completing the sending of code1, the display subsystem will not be powered off (the power-off condition is not met).

[0103] After completing the download of code 1, the software side (such as the display driver) downloads code 2 to the display driver chip through the display subsystem. The download of code 2 includes: at frame time 1, the software side (such as the display driver) controls the corresponding usage count of the display subsystem to +1 (from 1 to 2). When the display subsystem is in the power-on state, the display subsystem is notified to download code 2. After receiving the notification of downloading code 2, the display subsystem sends code 2 to the display driver chip, and then controls the corresponding usage count of the display subsystem to -1 (from 2 to 1).

[0104] When code 2 is downloaded, the display subsystem is already powered on, and the time for powering on the display subsystem in frame time 1 is omitted. Compared with the aforementioned code download method 1, code 2 can be sent faster.

[0105] For details about the code method 2, please refer to the following Fig. 7A as well as Figure 7B The description of is not repeated here.

[0106] However, in code download method 2, after code download 2 is completed, the usage count corresponding to the display subsystem is 1, and it is not reduced from 1 to 0. As a result, after code download 2 is completed, the display subsystem cannot be powered off, and it will remain in the powered-on state during the remaining unlocking process. Because the wake-up mechanism was used to power on the display subsystem in advance before code download 1, the sleep mechanism corresponding to the wake-up mechanism should also be used to power off the display subsystem. However, the conditions for calling the sleep mechanism are not met when the screen is locked. It is necessary to wait until the system-on-chip chip is in an idle state to call the sleep mechanism to power off the display subsystem. For example, after this unlocking is completed and the unlocking success interface is displayed, the electronic device locks the screen again and enters the screen sleep state. At this time, the chip system on the chip also enters the sleep state, and the sleep mechanism can be called to control the display subsystem to power off.

[0107] Therefore, the code downloading method 2 has the following problem: after the display subsystem is powered on in advance before code downloading 1 using the wake-up mechanism, the display subsystem cannot be powered off after code downloading 2 is completed.

[0108] In order to solve the problem that code 2 may fail in frame time 1 due to power-on again in code downloading method 1, while not causing the problem in code downloading method 2, code downloading method 3 is proposed.

[0109] Method 3 for downloading code: In this method, before code1 is downloaded to the display driver chip through the display subsystem, the software side (such as the display driver) will call the count increase interface (such as the pm_runtime_resume_and_get() interface) to add 1 to the usage count corresponding to the display subsystem, so that the usage count changes from 0 to 1, and the display subsystem switches from the power-off state to the power-on state. Subsequently, the software side (such as the display driver) downloads code1 through the display subsystem: the software side (such as the display driver) controls the usage count corresponding to the display subsystem to be added by 1 again (from 1 to 2). When the display subsystem is in the power-on state, the display subsystem is notified to send code1 to the display driver chip, and then the usage count corresponding to the display subsystem is controlled to be -1 (from 2 to 1). After completing the sending of code1, the display subsystem will not be powered off.

[0110] After completing the download of code1, the software side (such as the display driver) downloads code2 to the display driver chip through the display subsystem. Wherein, downloading code2 includes: at frame time 1, the software side (such as the display driver) controls the usage count corresponding to the display subsystem to +1 (from 1 to 2). When the display subsystem is in the power-on state, the display subsystem is notified to send code2 to the display driver chip, and then the usage count corresponding to the display subsystem is controlled to -1 (from 2 to 1). Then, through the count reduction interface corresponding to the count increase interface (pm_runtime_put_sync() interface), the usage count corresponding to the display subsystem is again -1 (from 1 to 0), triggering the display subsystem to power off.

[0111] When downloading code 2, the display subsystem is already powered on, and the time for powering on the display subsystem in frame time 1 is omitted. Compared with the aforementioned code download method 1, code 2 can be sent faster. At the same time, after completing code 2 download, the display subsystem can be powered off during the remaining unlocking process.

[0112] Moreover, compared with the coding method 2, the coding method 3 does not change the original usage logic of the wake-up mechanism.

[0113] For details about the code method 3, please refer to the following Fig. 8A as well as Figure 8B The description of is not repeated here.

[0114] The following describes the software and hardware structures involved in implementing the brightness adjustment method.

[0115] Figure 5 This is an exemplary software and hardware structure block diagram of the brightness adjustment method in the embodiment of the present application.

[0116] The layered architecture divides the software into several layers, each with clear roles and division of labor. The layers communicate with each other through software interfaces. In some embodiments, the software framework is divided into five layers, from top to bottom: application layer, application framework layer, local service layer, hardware abstraction layer, and kernel layer. Figure 5 Also shown is the hardware layer that can interact with the kernel layer.

[0117] The application layer can include a series of application packages.

[0118] like Figure 5 As shown, the application package may include applications (also referred to as apps) such as gallery, camera, map, WLAN, music, calendar, call, navigation, and Bluetooth.

[0119] The application framework layer provides an application programming interface (API) and a programming framework for the applications in the application layer. The application framework layer includes some predefined functions.

[0120] The application framework layer may include modules such as fingerprint (FP) service (serveice) and the like.

[0121] The fingerprint service can be used to trigger the advanced graphics platform (AGP) service to determine whether to make a frame switching decision after receiving the unlock event sent by the fingerprint hardware abstraction layer. The frame switching decision includes whether the screen refresh rate corresponding to the screen needs to be switched when displaying the image to be displayed.

[0122] The native service layer may include modules such as advanced graphics platform services and the Android image engine (surfaceflinger, SF).

[0123] The high-level graphics platform service is used to determine whether to make a frame switching decision. If frame switching is to be done, it determines how to do it and notifies the Android image engine to do it.

[0124] The Android image engine is used to determine the screen refresh rate after time A. For example, in the case of determining frame cutting, it is determined whether the screen refresh rate corresponding to time A meets requirement A. If it does not meet requirement A, it is switched according to the preset rules. The switching rules include: when the electronic device is high-end, the screen refresh rate can be switched to 120hz, and when it is standard, the screen refresh rate can be switched to 60hz. Alternatively, the screen refresh rate is switched to the highest screen refresh rate supported by the electronic device. Among them, requirement A includes a screen refresh rate that is less than a preset refresh rate (for example, 60hz). In the case of determining not to cut frames, the screen refresh rate corresponding to time A can be used as the screen refresh rate corresponding to the screen when displaying the image to be displayed.

[0125] The Android image engine is also used to send the screen refresh rate corresponding to the screen to the hardware hybrid renderer. The Android image engine is also used to obtain images involved in the image displayed during the synthetic unlocking, such as obtaining background images and fingerprint icons, and sending the images involved in the image displayed during the synthetic unlocking to the hardware hybrid renderer involved below.

[0126] The hardware abstraction layer (HAL) is an interface layer located between the operating system kernel layer and other layers of the electronic device (such as the local service layer). Its purpose is to abstract the hardware and provide a virtual hardware platform for the operating system.

[0127] The hardware abstraction layer includes modules such as fingerprint hardware abstraction layer (FPHAL) and hardware composer (HWC).

[0128] The fingerprint hardware abstraction layer can be used to notify the fingerprint service to trigger the advanced graphics platform service to determine whether to make a frame switching decision after receiving the notification from the fingerprint driver.

[0129] The fingerprint hardware abstraction layer may also include a fingerprint hardware service. After receiving the unlocking event sent by the fingerprint driver, the fingerprint hardware service sends a display instruction to the display driver, and the display instruction is used to trigger the display driver to notify the mobile display subsystem to download the code.

[0130] The hardware mixed renderer is used to mix the images involved in the composite unlocking display image transmitted by the Android graphics engine (such as background images and fingerprint icons) into a frame of image to be displayed (such as the image displayed at frame time 1, the image displayed at frame time 2, etc.), and then send it to the display driver for display. Among them, the background image can be regarded as the lock screen image displayed during the unlocking process.

[0131] The hardware hybrid renderer is also used to send the image to be displayed and the screen refresh rate corresponding to the screen when displaying the image to be displayed to the display driver.

[0132] The kernel layer is the layer between hardware and software. The kernel layer can also be called the driver layer. The kernel layer can include fingerprint driver, touch panel (TP) driver, display driver (LCD driver) and other modules.

[0133] The touch screen driver can be used to receive the hardware interrupt corresponding to the touch operation sent by the screen, and based on the hardware interrupt corresponding to the touch operation, identify the touched control as an icon for unlocking such as a fingerprint icon, generate an unlock event, and then notify the fingerprint driver of the unlock event.

[0134] After receiving the unlock event, the fingerprint driver sends the unlock event to the fingerprint hardware abstraction layer to notify the fingerprint hardware abstraction layer to trigger the next operation.

[0135] The display driver can be used to control the power-on of the mobile display subsystem, send code download instructions to the mobile display subsystem, etc.

[0136] The display driver includes a screen early wake-up module, a local highlight mode control module, a power-on module, and a power-off module.

[0137] Among them, the screen early wake-up module is used to provide the early wake-up mechanism involved above.

[0138] The power-on module is used to call the power management interface to power on the mobile display subsystem.

[0139] The power-off module is used to call the power management interface to power off the mobile display subsystem.

[0140] The local highlight control module carries a code sending instruction, which is used to send the code sending instruction to the mobile display subsystem after receiving the display instruction sent by the fingerprint hardware service.

[0141] The hardware layer may include hardware devices such as screens, mobile display subsystems, and display driver chips.

[0142] The screen can be used to receive a touch operation (such as a click operation on a fingerprint icon) and send a hardware interrupt corresponding to the touch operation to the kernel layer. In some possible cases, it can be sent to the touch screen driver of the kernel layer.

[0143] For the functions of the display subsystem and the display driver chip, please refer to the above description, which will not be repeated here.

[0144] The following is based on Figure 5 An exemplary process flow of the brightness adjustment method in the present application is described.

[0145] Step 1. The screen receives an unlock operation (such as a click operation on a fingerprint icon), and sends the hardware interrupt corresponding to the unlock operation to the touch screen driver, which identifies the touched control as a fingerprint icon. Then the fingerprint driver is notified that the unlock operation is detected. Subsequently, the fingerprint driver sends the unlock event generated based on the unlock operation to the fingerprint hardware abstraction layer to notify the fingerprint hardware abstraction layer to trigger the next operation. The operations that trigger the fingerprint hardware abstraction layer to execute here include the following steps 2 and 3.

[0146] Step 2. The fingerprint hardware abstraction layer notifies the fingerprint service to trigger the advanced graphics platform service to determine whether to make a frame cutting decision. The advanced graphics platform service notifies the Android image engine whether to make a frame cutting decision. In the case of determining frame cutting, the Android image engine determines whether the screen refresh rate corresponding to time A meets requirement A. If it does not meet requirement A, it switches according to preset rules. For example, when the electronic device is high-end, the screen refresh rate when displaying the image to be displayed can be switched to 120hz, and when it is standard, the screen refresh rate when displaying the image to be displayed can be switched to 60hz. Subsequently, the Android image engine sends the screen refresh rate corresponding to the screen when displaying the image to be displayed to the hardware hybrid renderer, and sends the images involved in the synthesized image to be displayed to the hardware hybrid renderer. The hardware hybrid renderer mixes the images involved in the synthesized image to be displayed transmitted by the Android image engine (such as background images and images such as fingerprint icons) into the image to be displayed.

[0147] Step 3. The fingerprint hardware abstraction layer sends a display instruction to the display driver. In some possible cases, the display instruction includes triggering the display of part or all of the unlock prompt information. Part or all of the unlock prompt information involved here may include the fingerprint spot involved above. When the display driver displays part of the unlock prompt information, other unlock prompt information can be used in the form of an image as an image involved in synthesizing the image to be displayed, and the hardware hybrid renderer synthesizes the image to be displayed based on it.

[0148] Step 4. After receiving the display instruction, the display driver triggers the display of part or all of the unlock prompt information (such as fingerprint spot), and displays the image to be displayed, so that the screen brightness remains unchanged before and after the unlock prompt information is displayed. Keeping the screen brightness unchanged includes: the display driver notifies the mobile display subsystem to send code1 to the display driver chip, so that the display driver chip adjusts the grayscale value of the pixels in the screen according to the grayscale value coefficient A at frame time 1 based on code1, and displays the first frame image on the screen after the grayscale value of the pixels is reduced. Then, at frame time 1, the display driver notifies the mobile display subsystem to send code2 to the display driver chip, so that the display driver chip adjusts the grayscale value of the pixels in the screen according to the grayscale value coefficient B at frame time 2 based on code2, and displays the second frame image on the screen after the grayscale value of the pixels is reduced.

[0149] It should also be understood that there is no particular order in which step 2 and step 3 are performed. Figure 5 The circle mark ① in the figure is Figure 5 The circle mark ② in the figure, step 3 is Figure 5 The circle mark in the middle is ③. Step 4 is Figure 5 The circle mark ④.

[0150] The following is based on Figure 5 The software and hardware structure block diagram involved in the above-mentioned coding method 1 to coding method 3 describes in detail the module interaction involved.

[0151] Firstly based on Fig. 6A as well as Figure 6B Describe the module interaction process involved in code method 1 and the effect diagram involved in code method 1.

[0152] like Fig. 6A As shown, in the code download mode 1, after the fingerprint hardware service (located in the fingerprint hardware abstraction layer) receives the unlock event, it sends a display instruction (32) to the local highlight control module (located in the display driver). The display instruction is used to trigger the local highlight control module to prepare the code and send the code to the display driver chip through the display subsystem. In some possible cases, the display instruction is also used to trigger the display of part of the unlock prompt information on the screen with the screen brightness adjusted. After receiving the display instruction, the local highlight control module. Code 1 (321a) is downloaded to the display driver chip (located in the hardware layer) through the display subsystem (located in the hardware layer). Then at frame time 1, the display driver chip adjusts the screen brightness based on code 1 so that the screen brightness remains at screen brightness A. In some possible cases, the first frame image (321b) can be displayed on the screen at frame time 1. At frame time 1, code 2 (322a) is downloaded to the display driver chip through the display subsystem. If the display driver chip can receive code 2 before frame time 2, the display driver chip can adjust the screen brightness based on code 2 at frame time 2 so that the screen brightness remains at screen brightness A. In some possible cases, a second frame image (322b) may be displayed in the frame time 2 screen.

[0153] Combine the following Figure 6B The content shown in (1) in the following describes the detailed process involved in code method 1. This process can be referred to Figure 6B Description of steps S321a, S21a, step S322a and step S22a in (1).

[0154] S321a. The local highlight mode control module sends code 1 to the display driver chip through the display subsystem.

[0155] After receiving the display instruction, the local highlight mode control module generates code 1. The code 1 carries at least the grayscale value coefficient (here, grayscale value coefficient A) for adjusting the pixels in the screen.

[0156] In some possible cases, the code1 may also include at least one of the following contents.

[0157] Content 1. The code 1 may also include a display brightness value A of the screen. The screen brightness corresponding to time A is less than the preset brightness. Here, the display brightness value A is the minimum display brightness when the working mode of the pixel in the screen is the direct current mode. The subsequent display driver chip can adjust the screen brightness corresponding to the frame time 1 based on the display brightness value A and the grayscale value coefficient A. For the details of the process, please refer to the following description of step S20, which will not be repeated here.

[0158] Content 2. The code 1 may also include whether to display the unlock prompt information and the location where the unlock prompt information is displayed.

[0159] Content 3. Grayscale value of each pixel on the screen in frame time 1 (before lowering). The grayscale value of each pixel on the screen in frame time 1 can be obtained by the grayscale value corresponding to each pixel in the image to be displayed in frame time 1. Or, it is a fixed parameter of the electronic device when the screen is locked.

[0160] It should be noted that the display brightness value A corresponding to different electronic devices may be different. It is a parameter pre-recorded in the electronic device.

[0161] Here, the process of downloading code1 to the display driver chip through the display subsystem may refer to the description of step S21a below.

[0162] S21a. The display subsystem is powered on, sends code 1 to the display driver chip, and then is powered off.

[0163] like Figure 6B As shown in (2), the process of the local highlight mode control module downloading code1 to the display driver chip (DDIC) through the display subsystem (MDSS) includes: the local highlight mode control module calls the power management interface to power on the display subsystem. After the display subsystem is powered on, the local highlight mode control module notifies the display subsystem to send code1 to the display driver chip. After completing the download of code1, the local highlight mode control module calls the power management interface to control the display subsystem to power off.

[0164] Here, the local highlight mode control module calls the power management interface to power on the display subsystem, including: the local highlight mode control module first calls the count increase interface (for example, the pm_runtime_resume_and_get() interface) to increase the usage count corresponding to the display subsystem by +1 (from 0 to 1), and when the usage count increases from 0 to 1, the power management interface is called to power on.

[0165] The local highlight mode control module calls the power management interface to power off the display subsystem, including: the local highlight mode control module first calls the count reduction interface (for example, the pm_runtime_put_sync() interface) to reduce the usage count corresponding to the display subsystem by -1 (from 1 to 0), and when the usage count is reduced from 1 to 0, the power management interface is called to achieve power off.

[0166] In some possible cases, the power management interface mentioned above may be an sde_power_resource_enable() interface.

[0167] Subsequently, at frame time 1, the display driver chip can use the grayscale value coefficient A carried in code1 to lower the grayscale value of the pixels in the screen, so that the screen brightness at frame time 1 is close to or equal to the screen brightness at time A (screen brightness A).

[0168] At frame time 1, the local highlight mode control module also sends code 2 to the display driver chip through the display subsystem. If the display driver chip can receive code 2 before frame time 2, the display driver chip adjusts the screen brightness based on code 2. If the display driver chip does not receive code 2 before frame time 2, the display driver chip still adjusts the screen brightness based on code 1. For details of this process, please refer to the following description of step S321a and step S22a.

[0169] S322a. The local highlight mode control module sends code 2 to the display driver chip through the display subsystem.

[0170] The local highlight mode control module generates code 2 and sends code 2 to the display driver chip through the display subsystem at frame time 1.

[0171] In some possible cases, the method of generating code2 includes: adjusting the parameters different from those in code1 and code2, and keeping the same parameters (such as display brightness value A) unchanged. For example, the grayscale value coefficient A in code1 is adjusted to the grayscale value coefficient B. When code1 carries the grayscale value of each pixel in the screen during frame time 1 and the grayscale value is related to the image to be displayed, the grayscale value of each pixel in the screen during frame time 1 is adjusted to the grayscale value of each pixel in the screen during frame time 2. The grayscale value of each pixel in the screen during frame time 2 can be obtained by the grayscale value corresponding to each pixel in the image to be displayed during frame time 2. Or, it is a fixed parameter of the electronic device when the screen is locked.

[0172] The process of downloading code1 to the display driver chip through the display subsystem may refer to the description of step S22a below.

[0173] S22a. The display subsystem is powered on, sends code 2 to the display driver chip, and then is powered off.

[0174] like Figure 6B As shown in (2), the process of the local highlight mode control module downloading code2 to the display driver chip (DDIC) through the display subsystem (MDSS) includes: the local highlight mode control module calls the power management interface to power on the display subsystem again. After the display subsystem is powered on, the local highlight mode control module notifies the display subsystem to send code2 to the display driver chip. After completing the download of code2, the local highlight mode control module calls the power management interface to control the display subsystem to power off.

[0175] Here, for the interfaces involved in powering on and off, please refer to the above description of step S21a, which will not be repeated here.

[0176] Since the power-on of the display subsystem involves the interaction of interfaces, the switching of the hardware from the power-off state to the power-on state will consume more time in frame time 1. If the display subsystem can only send code2 to the display driver chip after powering on again in frame time 1, there is a situation where code2 cannot be received before frame time 2. Figure 6B As shown in (2), the display driver chip obtains code2 at frame time 2, so code1 is still effective at frame time 2, and code2 can be effective at frame time 3. At frame time 2, the display driver chip still uses the grayscale value coefficient A carried in code1, but the response of the device is normal at frame time 2, so the grayscale value coefficient A (less than the grayscale value coefficient B) is used to lower the grayscale value of the pixels in the screen, which will make the screen brightness (screen brightness B) less than screen brightness A at frame time 2. Only by using the grayscale value coefficient B to lower the grayscale value of the pixels in the screen at frame time 3 can the pixels on the screen be equal to or close to screen brightness A.

[0177] The following is based on Fig. 7A as well as Figure 7B Describe the module interaction process involved in code method 2 and the effect diagram involved in code method 2.

[0178] like Fig. 7A As shown, in the coding method 2, after the fingerprint hardware service (located in the fingerprint hardware abstraction layer) receives the unlocking event, it first calls the display early wake-up module (located in the display driver) to power on the display subsystem (30), and then sends a display instruction (32) to the local highlight control module (located in the display driver) to trigger the local highlight control module to prepare the code and download the code to the display driver chip (located in the hardware layer) through the display subsystem (located in the hardware layer): including code1 (321a) and code2 (322a). Subsequently, at frame time 1, the display driver chip displays the first frame image based on code1 (321b) and at frame time 2, displays the second frame image based on code2 (322b). For other descriptions of the display instruction, step (32), step (321a), step (321b), step (322a), and step (322b), please refer to the aforementioned description. Fig. 6A The description of the relevant contents will not be repeated here.

[0179] Combine the following Figure 7B The content shown in (1) in the following describes the detailed process involved in code method 2. This process can be referred to Figure 7B Description of step S30, step S321a, step S21b, step S322a, step S22b and step S34 in (1).

[0180] S30. The display early wake-up module controls the display subsystem to power on.

[0181] The display early wake-up module controls the power-on of the display subsystem based on the wake-up mechanism. The process includes: calling the count increase interface (such as the pm_runtime_resume_and_get() interface) through the encoder_early_wakeup() interface to increase the usage count corresponding to the display subsystem by 1 (from 0 to 1), and when the usage count increases from 0 to 1, calling the power management interface to power on the display subsystem.

[0182] S321a. The local highlight mode control module sends code 1 to the display driver chip through the display subsystem.

[0183] After receiving the display instruction, the local highlight mode control module generates code1. The code1 carries at least the grayscale value coefficient (here, grayscale value coefficient A) of adjusting the pixels in the screen. For other related contents of the display instruction, reference can be made to the description of step S321a above.

[0184] like Figure 7B As shown in (2), before the local highlight mode control module sends code 1 to the display driver chip (DDIC) through the display subsystem (MDSS), the display subsystem is already in a powered-on state.

[0185] Here, step S321a includes: the local highlight mode control module first calls the count increase interface (such as pm_runtime_resume_and_get() interface) to increase the usage count corresponding to the display subsystem by +1 (from 1 to 2). Then execute step S21b to notify the display subsystem to send code1 to the display driver chip. Then, call the count reduction interface (such as pm_runtime_put_sync() interface) to decrease the usage count corresponding to the display subsystem by -1 (from 2 to 1). Since the usage count here is not reduced from 1 to 0, after completing code1, the display subsystem is still in the power-on state.

[0186] Subsequently, at frame time 1, the display driver chip can use the grayscale value coefficient A carried in code1 to lower the grayscale value of the pixels in the screen, so that the screen brightness at frame time 1 is close to or equal to the screen brightness at time A (screen brightness A).

[0187] In frame time 1, the local highlight mode control module further executes the following step S322a to send code 2 to the display driver chip through the display subsystem.

[0188] S322a. The local highlight mode control module sends code 2 to the display driver chip through the display subsystem.

[0189] Based on the usage rules of the display subsystem, before using the display subsystem to send code2 to the display driver chip, it is necessary to first call the count increase interface (such as pm_runtime_resume_and_get() interface) to increase the usage count corresponding to the display subsystem by 1 (from 1 to 2). Then execute the following step S22b to send code2 to the display driver chip.

[0190] S22b. The display subsystem sends code 2 to the display driver chip.

[0191] Here, the condition for executing step S22b includes that the display subsystem is powered on. Since the display subsystem is still powered on after sending code1, when the display subsystem sends code2 to the display driver chip, there is no need to wait for the display subsystem to be powered on again. In this way, the time for downloading code2 is shortened.

[0192] like Figure 7B As shown in (2), when the display subsystem (MDSS) downloads code 2 to the display driver chip (DDIC), the time for powering on the display subsystem again is saved, and the speed of completing the download of code 2 in frame time 1 is improved. Before frame time 2, the display driver chip can receive code 2, and adjust the grayscale value of the pixels in the screen in frame time 2 based on the grayscale value coefficient B carried in the code 2, so that the brightness of the screen in frame time 2 is equal to or close to the screen brightness A. For subsequent frame times (for example, frame time 3), the display driver chip still uses the grayscale value coefficient B to adjust the grayscale value of the pixels in the screen, so that the brightness of the screen continues to be equal to or close to the screen brightness A.

[0193] It should be noted that after sending code2, the display subsystem will call the count reduction interface (such as pm_runtime_put_sync() interface) to reduce the usage count of the display subsystem by -1 (from 2 to 1). Since the usage count here is not reduced from 1 to 0, the display subsystem is still powered on after completing code1.

[0194] The display subsystem can be powered off again only after the following step S34 is executed.

[0195] S34. After unlocking, when the screen is locked again, the screen sleep module controls the display subsystem to power off.

[0196] In some possible cases, the screen sleep module ( Fig. 7A (not shown) controlling the display subsystem to power off includes: calling a count reduction interface (e.g., a pm_runtime_put_sync() interface) through the sde_encoder_off_work() interface corresponding to the encoder_early_wakeup() interface to reduce the usage count corresponding to the display subsystem by -1 (from 1 to 0), and when the usage count increases from 0 to 1, calling the power management interface to power on the display subsystem.

[0197] The following is based on Fig. 8A as well as Figure 8B Describe the module interaction process involved in code method 3 and the effect diagram involved in code method 3.

[0198] like Fig. 8AAs shown, in the code downloading method 3, after the fingerprint hardware service (located in the fingerprint hardware abstraction layer) receives the unlocking event, it first notifies the power-on module (located in the display driver) to power on the display subsystem (31), and then sends a display instruction (32) to the local highlight control module (located in the display driver) to trigger the local highlight control module to prepare the code and download the code to the display driver chip (located in the hardware layer) through the display subsystem (located in the hardware layer): including downloading code1 (321a) and downloading code2 (322a). Subsequently, at frame time 1, the display driver chip displays the first frame image based on code1 (321b) and at frame time 2, displays the second frame image based on code2 (322b). After sending code2, the power-off module (located in the display driver) is notified to power off the display subsystem (33).

[0199] For other descriptions of the display instruction, step (32), step (321a), step (321b), step (322a), and step (322b), please refer to the aforementioned description. Fig. 6A The description of the relevant contents will not be repeated here.

[0200] Combine the following Figure 8B The content shown in (1) in the following describes the detailed process involved in code method 3. This process can be referred to Figure 8B Description of step S31, step S321a, step S21b, step S322a, step S22b and step S33 in (1).

[0201] S31. The power-on module controls the display subsystem to power on.

[0202] The power-on module controls the display subsystem to power on. The process includes: calling the count increase interface (such as the pm_runtime_resume_and_get() interface) to increase the usage count corresponding to the display subsystem by 1 (from 0 to 1), and when the usage count increases from 0 to 1, calling the power management interface to power on the display subsystem.

[0203] Subsequently, before executing step S321a and step S21b to download code1, the count increase interface will be used again to increase the usage count corresponding to the display subsystem by +1 (from 1 to 2). After completing the download of code1, although the count reduction interface (such as the pm_runtime_put_sync() interface) will be used to decrease the usage count corresponding to the display subsystem by -1 (from 2 to 1), the display subsystem is still in a powered-on state, so that in the subsequent steps S322a and S22b, code2 can be sent in frame time 1 without powering on again, thus saving the time for downloading code2.

[0204] in, Figure 8BSteps S321a, S21b, S322a, and S22b shown in (1) are the same as those described above. Figure 7B The relevant steps in (1) are the same, and you can refer to the above Figure 7B The description of (1) will not be repeated here.

[0205] 321a. The local highlight mode control module sends code 1 to the display driver chip through the display subsystem.

[0206] S21b. The display subsystem sends code 1 to the display driver chip.

[0207] S322a. The local highlight mode control module sends code 2 to the display driver chip through the display subsystem.

[0208] S22b. The display subsystem sends code 2 to the display driver chip.

[0209] After the download of code 2 is completed, the following step S33 is executed to power off the mobile display subsystem, thereby saving power consumption of the display subsystem.

[0210] S33. The power-off module controls the mobile display subsystem to power off.

[0211] The power-off module corresponding to the power-on module controls the power-off of the display subsystem. The process includes: calling the count reduction interface (for example, the pm_runtime_put_sync() interface) to reduce the usage count corresponding to the display subsystem by -1 (from 1 to 0), and when the usage count is reduced from 1 to 0, calling the power management interface to power off the display subsystem.

[0212] refer to Figure 8B As shown in (2), compared with Figure 7B In (2), at frame time 1, code 2 can be downloaded and after code 2 is downloaded, the display subsystem is in a power-off state. Figure 8B Other contents shown in (2) and Figure 7B (2) is the same as above. Figure 7B The description of (2) will not be repeated here.

[0213] It should be noted here that Figure 6B , Figure 7B as well as Figure 8B TE vsync refers to the vertical synchronization signal of the display (vertical sync), which is used to control the screen refresh image.

[0214] Compared with the above Figure 7B (1) and Figure 8B In (1), Fig. 9A more detailed module interaction diagram is shown, which is used to describe the module interactions involved in the method of powering on the display subsystem in advance before downloading the code (including the downloading code method 2 or the downloading code method 3).

[0215] For a description of this process, please refer to the following steps S11 to S19 and S21 to S26.

[0216] S11. Time A, an unlocking operation is detected.

[0217] When the unlock operation is a touch operation on the unlock icon on the screen, the scenario involved in step S11 may be the aforementioned Figure 2 The user interface described in (1).

[0218] In actual situations, the unlocking operation may also be a voice operation, etc., which is not limited in this embodiment of the present application.

[0219] S12. The fingerprint hardware abstraction layer receives an unlock event generated based on the unlock operation.

[0220] After receiving the unlock event, the fingerprint hardware abstraction layer can execute the following step S13 to send the screen refresh rate A and the screen brightness A corresponding to the time A to the display driver. The following step S14 can also be executed to send a display instruction to the display driver to trigger the display driver to notify the display subsystem to download the code.

[0221] S13. The display driver receives the screen refresh rate A and the screen brightness A corresponding to the time A.

[0222] The screen refresh rate A here may be a screen refresh rate obtained based on the frame decision mentioned above. It is the screen refresh rate of the screen in response to the unlocking operation. The screen refresh rate A may be different from the screen refresh rate of the screen at time A.

[0223] The screen brightness A is used to determine whether the grayscale value of the pixels in the screen needs to be lowered.

[0224] S14. The fingerprint hardware abstraction layer sends a display instruction to the display driver.

[0225] For the display instruction and its function, please refer to the description of the relevant content in the aforementioned step (32), which will not be repeated here.

[0226] S15. The fingerprint hardware abstraction layer controls the mobile display subsystem to power on.

[0227] In the coding mode 2, the process of the fingerprint hardware abstraction layer controlling the mobile display subsystem to power on can refer to the above description of step S30, which will not be repeated here.

[0228] In the coding mode 3, the process of the fingerprint hardware abstraction layer controlling the mobile display subsystem to power on can refer to the above description of step S31, which will not be repeated here.

[0229] S16. The display driver sends code 1 to the display driver chip through the display subsystem.

[0230] In the code downloading method 2, the process of the display driver downloading code 1 to the display driver chip through the display subsystem can refer to the above Figure 7B The description of step S321a and step S21b shown in (1) will not be repeated here.

[0231] In the code downloading method 3, the process of the display driver downloading code 1 to the display driver chip through the display subsystem can refer to the above Figure 8B The description of step S321a and step S21b shown in (1) will not be repeated here.

[0232] S17. The display driver chip obtains the display brightness value A and the grayscale value coefficient A in code1.

[0233] S18. At frame time 1, the display driver chip reduces the grayscale value of the pixels in the screen based on the grayscale value coefficient A, so as to control the brightness of the screen at frame time 1 to be equal to or close to the screen brightness A.

[0234] S19. The display driver chip obtains the gamma curve corresponding to the display brightness value A and the screen refresh rate A.

[0235] like Fig.10 As described in, the gamma curve (color correction curve) records the correspondence between the grayscale value of the pixel in the screen and the on-voltage (Vdata) mapping value of the pixel. The Vdata mapping value can be converted into the on-voltage of the pixel in the screen. The larger the on-voltage, the greater the brightness of the pixel.

[0236] Generally speaking, the pixels in the screen have three display channels (red / green / blue channels), so the gamma curve corresponding to the display brightness value A and the screen refresh rate A includes a set of gamma curves (gamma curves corresponding to the three channels). Fig.10 The middle curve 401 may represent the correspondence between the grayscale value of the pixel and the on-voltage (Vdata) mapping value of the blue channel. The curve 402 may represent the correspondence between the grayscale value of the pixel and the on-voltage (Vdata) mapping value of the red channel. The curve 403 may represent the correspondence between the grayscale value of the pixel and the on-voltage (Vdata) mapping value of the green channel.

[0237] In some possible cases, the larger the display brightness value corresponding to the gamma curve, the higher the screen brightness of the screen when the pixels in the screen are turned on based on the gamma curve. Fig.11 As shown, gamma curve 21 corresponds to the display brightness value at time A, and gamma curve 22 corresponds to display brightness value A (greater than the display brightness value at time A). After the display brightness value of the screen at frame time 1 is increased, it is necessary to lower the grayscale value of the pixels in the screen to make the screen brightness close to or equal to the screen brightness at time A. Here, pixel A in the screen is used as an example for explanation. If the grayscale value of pixel A is 250, the corresponding on-voltage (Vdata) mapping value of channel 1 of pixel A in gamma curve 21 is 350. After the grayscale value of pixel A is lowered to point B, the corresponding on-voltage (Vdata) mapping value of channel 1 of pixel A is still 350, so that the brightness of channel 1 of pixel A when it is turned on based on gamma curve 22 is equal to or close to that when it is turned on based on gamma curve 21. However, if the grayscale value is not depressed, the Vdata mapping value of pixel A in gamma curve 22 is greater than 350, and channel 1 of pixel A is brighter when it is turned on based on gamma curve 22 than when it is turned on based on gamma curve 21. All pixels on the screen follow this rule.

[0238] It should be noted here that Fig.12 As shown, different gamma curves correspond to different curve coefficients. Fig.12 The curve coefficient corresponding to the gamma curve 11 is 1, and the curve coefficient corresponding to the gamma curve 12 is 2. In some possible cases, the corresponding relationship between the brightness when a channel in a pixel is turned on (emitting light) and the grayscale value of the pixel can be expressed as: brightness = (grayscale value / 255) * curve coefficient.

[0239] S20. Within frame time 1, the display driver chip displays the first frame image on the screen with a reduced grayscale value by displaying the gamma curve corresponding to the brightness value A and the screen refresh rate A.

[0240] The gamma curve corresponding to the display brightness value A and the screen refresh rate A is recorded as gamma curve A. The gamma curve A can also be regarded as a gamma curve corresponding to the display brightness value A in a set of gamma curves corresponding to the screen refresh rate A. Here, the gamma curve corresponding to the display brightness value A can also be regarded as corresponding to the preset brightness.

[0241] In the case where the first frame image does not include the fingerprint spot, displaying the first frame image on the screen after the grayscale value is reduced through the gamma curve A includes: the display driver chip determines the on-voltage 1 corresponding to pixel 1 on the channel through the gamma curve A and the grayscale value of pixel 1 in the screen; pixel 1 is a pixel whose grayscale value is reduced based on the grayscale value coefficient A. Then the screen display chip controls the on-voltage of pixel 1 in the screen on the display channel to be on-voltage 1, and the turned-on pixel 1 is used to display the pixel corresponding to pixel 1 in the first frame image.

[0242] In the case where the first frame image includes a fingerprint spot, displaying the first frame image on the screen after the grayscale value is reduced through the gamma curve A includes: the display driver chip determines the on-voltage 1 corresponding to pixel 1 on the channel through the gamma curve A and the grayscale value of pixel 1 in the screen; pixel 1 is a pixel whose grayscale value is reduced based on the grayscale value coefficient A, and pixel 1 is used to display the content other than the fingerprint spot in the first frame image. The electronic device determines the on-voltage 2 corresponding to pixel 2 on the display channel through the grayscale value 1. Pixel 2 is used to display the content in the fingerprint spot; the grayscale value 1 is the grayscale value of the pixel that displays the fingerprint spot. Then, the screen display chip controls the on-voltage of pixel 1 on the display channel to be the on-voltage 1, and controls the on-voltage of pixel 2 on the display channel to be the on-voltage 2, and the pixel 1 after being turned on displays the pixel corresponding to pixel 1 in the first frame image, and the pixel 2 after being turned on displays the pixel corresponding to pixel 2 in the first frame image. In this way, when the first frame image is displayed, the screen brightness value is close to or equal to the screen brightness A.

[0243] S21. The display driver downloads code 2 to the display driver chip through the display subsystem.

[0244] In the code downloading method 2, the process of the display driver downloading code 2 to the display driver chip through the display subsystem can refer to the above Figure 7B The description of step S322a and step S22b shown in (1) will not be repeated here.

[0245] In the code downloading method 3, the process of the display driver downloading code 2 to the display driver chip through the display subsystem can refer to the above Figure 8B The description of step S322a and step S22b shown in (1) will not be repeated here.

[0246] S22. The display driver chip obtains the display brightness value A and the grayscale value coefficient B in code2.

[0247] S23. At frame time 2, the display driver chip reduces the grayscale value of the pixels in the screen based on the grayscale value coefficient B, so as to control the brightness of the screen at frame time 2 to be equal to or close to the screen brightness A.

[0248] S24. The display driver chip obtains the gamma curve corresponding to the display brightness value A and the screen refresh rate A.

[0249] The description of the gamma curve here is the same as that in the aforementioned step S19. Please refer to the aforementioned description of step S19 and will not be repeated here.

[0250] S25. Within frame time 2, the display driver chip displays the second frame image on the screen with a reduced grayscale value by using the gamma curve corresponding to the display brightness value A and the screen refresh rate A.

[0251] Step S25 is similar to the aforementioned step S20, where frame time 1 is changed to frame time 2, the first frame image is changed to the second frame image, and the grayscale value coefficient A is changed to the grayscale value coefficient B. Here, it is no longer the minimum.

[0252] It should be noted here that before completing the unlocking, the grayscale value coefficient B is also used to adjust the grayscale value of the pixels in the screen during the display of subsequent frame images after the second frame image, so that when displaying subsequent frame images, the screen brightness value is close to or equal to the screen brightness A.

[0253] S26. The display driver controls the mobile display subsystem to power off.

[0254] In the code download mode 2, the process of the display driver controlling the mobile display subsystem to power off can refer to the above Figure 7B The description of step S34 shown in (1) is not repeated here.

[0255] In the code download mode 3, the process of the display driver controlling the mobile display subsystem to power off can refer to the above Figure 8B The description of step S33 shown in (1) is not repeated here.

[0256] It should be noted here that the step of following the code occurs when the screen brightness corresponding to time A is greater than the preset brightness. The preset brightness can be understood as the brightness converted from the minimum display brightness (recorded as display brightness value A) in the DC mode of the pixel in the screen. Fig.13 A schematic diagram of the corresponding relationship between the display brightness value (DBV) and the screen brightness (unit nit) is shown in FIG. In some possible cases, the preset brightness A mentioned above can be expressed as 90 nit, which is converted from the DBV corresponding to 90 nit, for example, 1200.

[0257] It should also be noted that the corresponding relationship between the gamma curve, the screen refresh rate and the display brightness value can be understood as follows: different screen refresh rates correspond to a set of gamma curves. Any gamma curve in the set of gamma curves corresponds to a display brightness value, or the screen brightness corresponding to the display brightness value.

[0258] It should also be noted that there is no particular order in which the above steps S13 and S14 are executed, and there is no particular order in which the above steps S25 and S26 are executed.

[0259] It should be noted here that the gamma curve can correspond to the display brightness value in addition to not corresponding to the display brightness value. Instead, it can correspond to the screen brightness. When the gamma curve corresponds to the screen brightness, the preset brightness is the minimum screen brightness that switches the screen's working mode from PWM mode to DC mode, and does not need to be converted through the display brightness value.

[0260] Fig.14 An exemplary flow chart of the brightness adjustment method is shown.

[0261] For the process of adjusting the brightness of the screen when unlocking, please refer to the following description of steps S201 to S206.

[0262] S201. At time A, the electronic device detects an unlocking operation.

[0263] For the description of step S201, reference may be made to the aforementioned step S11, which will not be repeated here.

[0264] S202. In response to the unlocking operation, the electronic device determines the screen refresh rate A and the screen brightness A corresponding to the time A.

[0265] S203. The electronic device determines whether the screen brightness A is less than the preset brightness A.

[0266] When the screen brightness A is less than the preset brightness A, the following steps S204a and S205a are executed.

[0267] When the screen brightness A is greater than or equal to the preset brightness A, execute the following step S204b.

[0268] S204a. The electronic device reduces the grayscale value of the pixels in the screen based on the grayscale value coefficient A, and displays the first frame image on the screen after the grayscale value is reduced through the preset brightness A and the gamma curve corresponding to the screen refresh rate A, so that the screen brightness corresponds to the screen brightness A when displaying the first frame image.

[0269] For the description of step S204a, reference may be made to the aforementioned description of steps S15 to S19 and step S20, which will not be repeated here.

[0270] S205a. The electronic device reduces the grayscale value of the pixels in the screen based on the grayscale value coefficient B, and displays subsequent frame images on the screen after the grayscale value is reduced through the preset brightness A and the gamma curve corresponding to the screen refresh rate A, so that the screen brightness of subsequent frame images corresponds to the screen brightness A, and the grayscale value coefficient B is greater than the grayscale value coefficient A.

[0271] For the description of step S205a, reference may be made to the aforementioned description of steps S21 to S25, which will not be repeated here.

[0272] S204b. The electronic device keeps the grayscale value of the pixels in the screen unchanged, and displays the image on the screen with the unchanged grayscale value through the gamma curve corresponding to the screen brightness A and the screen refresh rate A, so that the screen brightness corresponds to the screen brightness A when displaying the image.

[0273] In step S204b, there is no need to adjust the grayscale value of the pixels in the screen. In frame time 1, the electronic device keeps the grayscale value of the pixels in the screen the same as that in time A, and displays the first frame image. In frame time 2, the electronic device keeps the grayscale value of the pixels in the screen the same as that in time A, and displays the second frame image.

[0274] In the case where the fingerprint spot is not included in the first frame image, the electronic device displays the first frame image including: the electronic device determines the on-voltage a corresponding to pixel a1 on the display channel through the gamma curve B and the grayscale value of pixel a in the screen. Among them, the gamma curve B is a gamma curve corresponding to the display brightness at time A in a group of gamma curves associated with the screen refresh rate A. Pixel a1 is a pixel in the screen with the same grayscale value as time A. The gamma curve corresponding to the display brightness at time A can also be regarded as the gamma curve corresponding to the screen brightness A.

[0275] In the case where the first frame image includes a fingerprint spot, the electronic device displays the first frame image including: the electronic device determines the on-voltage a1 corresponding to pixel a1 on the display channel through gamma curve B and the grayscale value of pixel a in the screen. Among them, gamma curve B is a gamma curve corresponding to the display brightness at time A in a group of gamma curves associated with screen refresh rate A. Pixel a1 is a pixel in the screen with the same grayscale value as time A, and pixel a1 is used to display the content other than the fingerprint spot in the first frame image. The electronic device determines the on-voltage b corresponding to pixel b on the display channel through grayscale value 1. Pixel b is used to display the content in the fingerprint spot image; grayscale value 1 is the grayscale value of the pixel displaying the fingerprint spot. Then, the screen display chip controls the on-voltage of pixel a1 on the display channel to be the on-voltage a, and controls the on-voltage of pixel b on the display channel to be the on-voltage b, and the pixel a1 after being turned on displays the pixel corresponding to pixel a1 in the first frame image, and the pixel b after being turned on displays the pixel corresponding to pixel b in the first frame image. The gamma curve corresponding to the display brightness at time A can also be regarded as the gamma curve corresponding to the screen brightness A.

[0276] It should also be noted that the device specifically used for displaying the first frame image in the electronic device includes a screen display driver.

[0277] The contents related to displaying the second frame image are similar to those related to displaying the first frame image, and will not be repeated here.

[0278] S206. The electronic device displays an interface after unlocking is completed or an interface of unlocking failure.

[0279] It should be noted that after the electronic device downloads code1, it needs to download code2 at frame time 1. You can use a delayed work queue to delay the instruction of downloading code2 to frame time 1 after the instruction of downloading code1. Or you can use other delay methods, such as the usleep_range() interface. The delay time can be dynamically configured according to the screen refresh rate so that code2 is sent at frame time 1.

[0280] It should also be noted that when the display subsystem sends code1 to the display driver chip, it can send it in syncTE mode, and code2 and code1 hold the same panellock lock for sending, so as to avoid other codes being transmitted to the display driver chip after code1 is sent and before code2 is sent, which may affect the display driver chip's reception or execution of code2.

[0281] The following is based on Fig.15 Diagram describing the workings involved in a pixel on a screen.

[0282] Here, the description is made assuming that the light source of the pixel is generated by an organic light-emitting diode (OLED).

[0283] Fig.15 (1) in FIG. 1 shows an exemplary circuit diagram of a working circuit of an OLED, wherein ELVDD represents a positive voltage, ELVSS represents a negative voltage, and Vdata is a conduction voltage corresponding to the OLED. The electronic device can control the conduction of the OLED by controlling the voltage input to the EM terminal. Fig.15 As shown in (2), the EM terminal can input a low level for part of the time in a cycle (T), and when the part of the time is less than the length of a cycle, a high level is input for the rest of the time in the cycle. When the low level is input, the OLED is turned on and can emit light, and when the high level is input, the OLED is not turned on and cannot emit light. When the OLED is turned on, the smaller the Vdata, the greater the current flowing through the OLED, and the brighter the OLED (i.e., the greater the brightness). In some possible cases, the OLED can be turned on by controlling the transistor T1 or the transistor T2 to turn on.

[0284] In some possible cases, the aforementioned existence of two working modes for pixels in the screen is achieved by controlling the voltage input to the EM terminal. When the target brightness of the screen is less than the preset brightness A, the target brightness of the screen is low, and the working mode of the pixel needs to be set to PWM mode to achieve this lower target brightness. At this time, the EM terminal can input a low level for part of the time in a cycle (T) and a high level for the rest of the time. In this way, the OLED can not emit light continuously (that is, each pixel does not emit light continuously) so that the target brightness of the screen is less than the preset brightness A. When the target brightness of the screen is greater than or equal to the preset brightness A, the working mode of the pixel in the screen is the DC mode. At this time, the EM terminal inputs a low level in one cycle (T).

[0285] It should be understood that the high level mentioned above can be represented by 1, and the low level can be represented by 0. The roles of the high and low levels are only illustrative, and the roles of the high and low levels can be interchangeable in actual applications.

[0286] like Fig.15 As shown in (1), the working state of OLED includes emitting light and not emitting light. When emitting light, the EM terminal inputs a low level, and the Gn-1 terminal and the Gn terminal input a high level. When not emitting light, it includes a reset state and a compensation state. In the reset state, the EM terminal inputs a high level, the Gn-1 terminal inputs a low level, and the Gn terminal inputs a high level. In the compensation state, the EM terminal inputs a high level, the Gn-1 terminal inputs a high level, and the Gn terminal inputs a low level.

[0287] The method for determining the grayscale value coefficient B is introduced below.

[0288] The grayscale value coefficient B can be determined based on the screen brightness at time A and the aforementioned preset brightness. The greater the screen brightness at time A, the greater the grayscale value coefficient B. The greater the aforementioned preset brightness, the smaller the grayscale value coefficient B.

[0289] The relationship between the grayscale value coefficient B and the screen brightness at time A and the preset brightness A can satisfy the following gamma formula: grayscale value coefficient B = (screen brightness at time A / preset brightness A) 1 / x The above gamma formula is a variation of the classic gamma formula. The classic gamma formula is: screen brightness = (grayscale value / 256) x . Wherein, x represents the curve coefficient corresponding to the gamma curve, which may be 2, for example.

[0290] The following describes a method for determining the grayscale value coefficient A.

[0291] The grayscale value coefficient A is determined based on the grayscale value coefficient B and the screen brightness at time A. Wherein, in the case of preset brightness determination, the grayscale value coefficient A increases as the screen brightness at time A increases.

[0292] In some possible cases, N binding points can be set in the PWM interval, and then the grayscale value coefficient A is calculated using linear interpolation between the N binding points. The PWM interval is the brightness interval when the screen works in the PWM dimming mode. For example, the PWM interval can be a DBV value of 0-1000. If each DBV value needs to be fine-tuned, the number of binding points N can be 1000. When the value of the PWM interval and the number of binding points are determined, the screen brightness at time A can be determined. Combined with the relevant instructions for obtaining the grayscale value coefficient B in the aforementioned embodiment, when the grayscale value coefficient B and the screen brightness at time A are determined, an optimal grayscale value coefficient A can always be obtained so that the screen brightness before and after the fingerprint spot is displayed still maintains the screen brightness at time A. The grayscale value coefficient A is empirical data obtained based on multiple experiments.

[0293] Different screen modules and screen brightness at time A can affect the screen brightness peak, and the screen brightness peak can affect the value of the grayscale value coefficient A. Therefore, the value of the grayscale value coefficient A is affected by the characteristics of the screen module and the screen brightness at time A. Specifically, when the screen module is the same, the greater the screen brightness at time A (that is, the closer to the preset brightness), the smaller the screen brightness peak; conversely, the smaller the screen brightness at time A (that is, the more it deviates from the preset brightness A), the larger the screen brightness peak. The smaller the screen brightness peak, the larger the grayscale value coefficient A; conversely, the larger the screen brightness peak, the smaller the grayscale value coefficient A.

[0294] Fig.16It is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0295] The following is a specific description of the embodiment using an electronic device as an example. It should be understood that the electronic device may have more or fewer components than those shown in the figure, may combine two or more components, or may have different component configurations. The various components shown in the figure may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application specific integrated circuits.

[0296] The electronic device may include: a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194 and a subscriber identification module (SIM) card interface 195, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc.

[0297] It is to be understood that the structure illustrated in the embodiments of the present application does not constitute a specific limitation on the electronic device. In other embodiments of the present application, the electronic device may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0298] The processor 110 may include one or more processing units, for example, the processor 110 may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a memory, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0299] The controller can be the nerve center and command center of the electronic device. The controller can generate operation control signals according to the instruction operation code and timing signal to complete the control of fetching and executing instructions.

[0300] The processor 110 may also be provided with a memory for storing instructions and data.

[0301] In some embodiments, the processor 110 may include one or more interfaces. The interface may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc.

[0302] It is understandable that the interface connection relationship between the modules illustrated in the embodiments of the present application is only a schematic illustration and does not constitute a structural limitation on the electronic device. In other embodiments of the present application, the electronic device may also adopt different interface connection methods in the above embodiments, or a combination of multiple interface connection methods.

[0303] The charging management module 140 is used to receive charging input from a charger, where the charger can be a wireless charger or a wired charger.

[0304] The power management module 141 is used to connect the battery 142 , the charging management module 140 and the processor 110 .

[0305] The wireless communication function of the electronic device can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor and baseband processor.

[0306] The modulation and demodulation processor may include a modulator and a demodulator. The modulator is used to modulate the low-frequency baseband signal to be transmitted into a medium-high frequency signal. The demodulator is used to demodulate the received electromagnetic wave signal into a low-frequency baseband signal. The demodulator then transmits the demodulated low-frequency baseband signal to the baseband processor for processing.

[0307] The wireless communication module 160 can provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), infrared technology (IR), etc. for application in electronic devices.

[0308] In some embodiments, the antenna 1 of the electronic device is coupled to the mobile communication module 150, and the antenna 2 is coupled to the wireless communication module 160, so that the electronic device can communicate with the network and other devices through wireless communication technology. The wireless communication technology may include the global system for mobile communications (GSM), general packet radio service (GPRS), etc.

[0309] The electronic device realizes the display function through a GPU, a display screen 194, and an application processor.

[0310] The display screen 194 is used to display images, videos, etc. The display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD). The display panel can also be made of an organic light-emitting diode (OLED), an active-matrix organic light emitting diode or an active-matrix organic light emitting diode (AMOLED), a flexible light-emitting diode (FLED), miniled, microled, micro-oled, quantum dot light emitting diodes (QLED), etc. In some embodiments, the electronic device may include 1 or N display screens 194, where N is a positive integer greater than 1. In some possible cases, the display screen may also be referred to as a screen or a touch screen, etc.

[0311] NPU is a neural-network (NN) computing processor. It can quickly process input information by drawing on the structure of biological neural networks, such as the transmission mode between neurons in the human brain, and can also continuously self-learn.

[0312] The internal memory 121 may include one or more random access memories (RAM) and one or more non-volatile memories (NVM).

[0313] Random access memory may include static random-access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), etc.

[0314] Non-volatile memory may include disk storage devices and flash memory.

[0315] Flash memory can be divided into NOR FLASH, NAND FLASH, 3D NAND FLASH, etc. according to the operating principle, and can be divided into single-level cell (SLC), multi-level cell (MLC), etc. according to the potential level of the storage cell.

[0316] The pressure sensor 180A is used to sense pressure signals and convert the pressure signals into electrical signals.

[0317] The gyro sensor 180B may be used to determine the motion posture of the electronic device.

[0318] The air pressure sensor 180C is used to measure air pressure. In some embodiments, the electronic device calculates the altitude through the air pressure value measured by the air pressure sensor 180C to assist positioning and navigation.

[0319] The acceleration sensor 180E can detect the magnitude of the acceleration of the electronic device in various directions (generally three axes).

[0320] Distance sensor 180F, used to measure distance. Electronic devices can measure distance through infrared or laser.

[0321] The proximity light sensor 180G may include, for example, a light emitting diode (LED) and a light detector such as a photodiode.

[0322] The ambient light sensor 180L is used to sense the brightness of ambient light.

[0323] The fingerprint sensor 180H is used to collect fingerprints. Electronic devices can use the collected fingerprint characteristics to achieve fingerprint unlocking, access application locks, fingerprint photography, fingerprint call answering, etc.

[0324] The temperature sensor 180J is used to detect the temperature.

[0325] The touch sensor 180K is also called a "touch panel". The touch sensor 180K can be set on the display screen 194, and the touch sensor 180K and the display screen 194 form a touch screen, also called a "touch screen". The touch sensor 180K is used to detect touch operations acting on or near it. The touch sensor can pass the detected touch operation to the application processor to determine the type of touch event. Visual output related to the touch operation can be provided through the display screen 194. In other embodiments, the touch sensor 180K can also be set on the surface of the electronic device, which is different from the position of the display screen 194.

[0326] In the embodiment of the present application, the touch sensor 180K can be used to detect the user's operation on the fingerprint recognition area in the display screen 194, and transmit the detected touch operation to the fingerprint sensor 180H to determine that the event corresponding to the touch operation is a fingerprint unlocking event (unlocking event). The touch sensor 180K can also provide visual output related to the touch operation through the display screen 194. For example, after the user places a finger on the fingerprint recognition area in the display screen 194, the display screen 194 displays a fingerprint spot. In other embodiments, the touch sensor 180K can also be set on the surface of the electronic device, which is different from the position of the display screen 194.

[0327] The ambient light sensor 180L can be used to sense the ambient light brightness. The electronic device can adaptively adjust the brightness of the display screen 194 according to the perceived ambient light brightness. In an embodiment of the present application, the ambient light sensor 180L can be used to detect whether the electronic device is in a dark light environment (i.e., detect whether the ambient light brightness is lower than the preset ambient light brightness). The dark light environment is relative to the strong light environment, for example, the ambient light brightness of the dark light environment is lower than 50lux. If the ambient light sensor 180L detects that the electronic device is in a dark light environment, the electronic device can reduce the gray scale of the screen pixels within the first frame time after entering the DC dimming to improve the problem of sudden changes in screen brightness within the first frame time; if the ambient light sensor 180L detects that the electronic device is in a strong light environment, the electronic device may not reduce the gray scale of the screen pixels within the first frame time. Because, in a strong light environment, it is not easy for users to feel the sudden change in screen brightness in the first frame time.

[0328] In the embodiment of the present application, the display screen 194 may be an OLED screen. The fingerprint sensor 180H may be disposed below the display screen 194, specifically below a fingerprint recognition area on the display screen 194 (also referred to as a screen).

[0329] Electronic devices can be connected through SOC, DDIC ( Fig.16 The display function is realized by using a display screen 194 and the like.

[0330] Among them, DDIC can be used as the control core of the display screen 194, driving the display screen 194 to work, and receiving data from the SOC (processor 110), such as image data and some instructions. DDIC can send driving signals and data to the display panel of the display screen 194 in the form of electrical signals, and then realize the control of the screen brightness and color, so that image information such as letters and pictures can be displayed on the screen, and the screen refresh is completed, so that the display screen refreshes the picture according to the screen refresh rate.

[0331] The screen refresh rate is the number of times the display screen 194 refreshes the display screen in 1 second. For example, a 60 Hz refresh rate means that the display screen refreshes the display screen 60 times in 1 second. After the screen is unlocked successfully, the SOC can control the DDIC to increase the screen refresh rate to promptly respond to the user's touch operation on the screen.

[0332] The electronic device can also implement a fingerprint unlocking function through the SOC, DDIC, display screen 194 and fingerprint sensor 180H.

[0333] Among them, the fingerprint sensor 180H can be a CMOS / CCD sensor, or even a fisheye camera. When the user's finger is placed on the fingerprint recognition area, the light emitted by the display screen 194 will illuminate the finger, and the reflected light of the fingerprint will shine through the screen to the fingerprint sensor 180H under the screen. When the fingerprint is unlocked, in order to illuminate the finger more clearly, the DDIC can control the display screen 194 to display a fingerprint spot with a high grayscale value (such as a grayscale value of 255) in the fingerprint recognition area. The fingerprint spot is conducive to the fingerprint sensor 180H to collect clear fingerprints. The SOC can compare the collected fingerprint with the recorded fingerprint. If the collected fingerprint is consistent with the recorded fingerprint, the unlocking is confirmed to be successful.

[0334] The brightness adjustment method of OLED screens is different from that of liquid crystal display (LCD) screens. The brightness adjustment of OLED screens is not achieved by adjusting the screen backlight, but by controlling the screen brightness while controlling the screen pixel color. Moreover, when the screen brightness is lower than the preset brightness A (such as 75nit), the OLED screen uses PWM dimming mode (PWM mode); when the screen brightness is higher than the preset brightness A, the OLED screen uses DC dimming mode (DC mode). Usually, screen manufacturers will write this dimming logic into the driver integrated circuit (such as DDIC), which cannot be changed. The preset brightness A is the minimum screen brightness to enter DC dimming.

[0335] Here, the DC dimming mode changes the screen brightness by increasing or decreasing the circuit power. Changing the voltage or current can change the circuit power. The PWM dimming mode does not rely on changing the circuit power to change the screen brightness, but relies on the alternation of the screen on and off, that is, the screen does not emit light continuously, but alternates between lighting and extinguishing. When the screen brightness is reduced to a certain level, the light and dark changes of the three primary color pixels can no longer be reflected as color changes, and the color changes cannot be controlled. Therefore, the OLED screen does not use the DC dimming mode at low brightness, but uses the PWM dimming mode, that is, the actual current or voltage on the pixel is higher, and the color expression is not affected, but the brightness value perceived by the human eye is changed by changing the PWM duty cycle. As mentioned above Fig.15As shown in the figure, in one cycle, the more low levels there are, the larger the duty cycle is. The more high levels there are, the smaller the duty cycle is. When the duty cycle is 0, the OLED is not conducting and does not emit light.

[0336] In the embodiment of the present application, the processor 110 can call the computer instructions stored in the internal memory 121 to enable the electronic device to execute the method in the embodiment of the present application.

[0337] The present application also provides a chip system, which includes at least one processor for implementing the functions involved in the method executed by the electronic device in any of the above embodiments.

[0338] In one possible design, the chip system also includes a memory, which is used to store program instructions and data, and the memory is located inside or outside the processor.

[0339] The chip system may be composed of the chip, or may include the chip and other discrete devices.

[0340] Optionally, the processor in the chip system may be one or more. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0341] Optionally, the memory in the chip system may be one or more. The memory may be integrated with the processor or may be separated from the processor, which is not limited in the embodiment of the present application.

[0342] Exemplarily, the memory can be a non-transitory processor, such as a read-only memory ROM, which can be integrated with the processor on the same chip or can be set separately on different chips. The embodiments of the present application do not specifically limit the type of memory and the setting method of the memory and the processor.

[0343] Exemplarily, the chip system can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0344] The present application also provides a computer program product, which includes: a computer program (also referred to as code, or instruction), which enables a computer to execute the method executed by the electronic device in any of the above embodiments when the computer program is executed.

[0345] The present application also provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program (also referred to as code or instruction). When the computer program is executed, the computer executes the method executed by the electronic device in any of the above embodiments.

[0346] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0347] As used in the above embodiments, the term "when..." may be interpreted to mean "if..." or "after..." or "in response to determining..." or "in response to detecting...", depending on the context. Similarly, the phrases "upon determining..." or "if (the stated condition or event) is detected" may be interpreted to mean "if determining..." or "in response to determining..." or "upon detecting (the stated condition or event)" or "in response to detecting (the stated condition or event)", depending on the context.

[0348] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more listed items.

[0349] The terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Thus, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0350] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that contains one or more available media integration. The available medium can be a magnetic medium, (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk), etc.

[0351] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

Claims

1. A brightness adjustment method, characterized in that: The method comprises: The electronic device immediately displays the lock screen interface and controls the screen to work in pulse width modulation (PWM) mode; In response to a user touching a fingerprint recognition area in the screen, the electronic device controls the screen to switch from operating in the PWM mode to operating in the direct current DC mode, and lowers the grayscale value of the pixels in the screen according to a first ratio in a first frame time after the switching, so as to control the screen brightness of the screen in the first frame time to be equal to or close to the screen brightness in the first time; the first frame time at least includes the time when the electronic device displays the first frame after the switching; In the last frame time of the first frame time, switching the coefficient for reducing the screen grayscale value from the first ratio to a second ratio; In the second frame time, the electronic device lowers the grayscale value of the pixel in the screen according to the second ratio, so as to control the screen brightness of the screen in the second frame time to be equal to or close to the screen brightness of the first time; the second ratio is higher than the first ratio, and the second frame time is the next frame time of the last frame time of the first frame time; when the screen works in the DC mode, if the grayscale value of the pixel in the screen is lowered by using the second ratio in the first frame time, the screen brightness of the screen in the first frame time will be higher than the screen brightness of the first time; The electronic device further collects a fingerprint after the switching. If the collected fingerprint is consistent with the recorded fingerprint, after the second frame time, the electronic device displays an interface after successful unlocking.

2. The method according to claim 1, characterized in that When collecting fingerprints, the method further includes: The electronic device displays a fingerprint spot image in the fingerprint recognition area, and pixels used to display the fingerprint spot image have a first grayscale value, which is higher than an average grayscale value of pixels in the screen.

3. The method according to claim 2, characterized in that Lowering the grayscale values ​​of the pixels in the screen according to the first ratio specifically includes: lowering the grayscale values ​​of the pixels in the area of ​​the screen other than the fingerprint recognition area according to the first ratio; Lowering the grayscale values ​​of the pixels in the screen according to the second ratio specifically includes: lowering the grayscale values ​​of the pixels in an area of ​​the screen other than the fingerprint recognition area according to the second ratio.

4. The method according to claim 1, characterized in that: When the screen operates in the PWM mode, the screen brightness of the screen is below the first screen brightness, which is the maximum screen brightness of the screen when operating in the PWM mode and the minimum screen brightness of the screen when operating in the DC mode.

5. The method according to claim 1, characterized in that: When the screen operates in the DC mode, the screen brightness of the screen is above a first screen brightness, and the first screen brightness is the minimum screen brightness of the screen when operating in the DC mode.

6. The method according to any one of claims 1 to 5, characterized in that The method further comprises: In response to the unlocking operation, before the electronic device lowers the grayscale value of the pixels in the screen according to the first ratio, the electronic device controls the display subsystem to power on; the display subsystem is used to control the screen driving chip to lower the grayscale value of the pixels in the screen according to the first ratio or the second ratio; After the display subsystem controls the screen driver chip to lower the grayscale values ​​of the pixels in the screen according to the second ratio, the electronic device controls the display subsystem to power off; wherein, between the time when the display subsystem is powered on and the time when the screen driver chip is controlled to lower the grayscale values ​​of the pixels in the screen according to the second ratio, the display subsystem remains powered on.

7. The method according to claim 6, characterized in that After the electronic device controls the display subsystem to be powered on, the method further includes: The electronic device sends a first instruction to the screen display chip through the display subsystem, wherein the first instruction carries the first ratio; After receiving the first instruction, the screen display chip reduces the grayscale value of the pixels in the screen based on the first ratio.

8. The method according to claim 7, characterized in that After the grayscale values ​​of the pixels in the screen are lowered according to the first ratio, when the screen displays the first image in the first frame time, the method further includes: The electronic device sends a second instruction to the screen display chip through the display subsystem, wherein the second instruction carries the second ratio; After receiving the second instruction, the screen display chip reduces the grayscale value of the pixels in the screen based on the second ratio when the second frame time is reached.

9. The method according to claim 8, characterized in that The electronic device controls the display subsystem to power on, specifically including: The electronic device calls a power management interface in a display driver to control the display subsystem to power on.

10. The method according to claim 9, characterized in that The method further comprises: When a first preset time has passed since the display subsystem sent the second instruction to the screen display chip, the electronic device calls the power management interface to control the display subsystem to power off.

11. The method according to claim 9 or 10, characterized in that: The method further comprises: After the first time, before the electronic device controls the display subsystem to power on, the system-on-chip chip of the electronic device is in an idle state, and the display subsystem is powered off by a sleep mechanism; the sleep mechanism corresponds to a wake-up mechanism, and the wake-up mechanism is used to respond to a wake-up operation to wake up the system-on-chip chip when the system-on-chip chip is idle; when the system-on-chip chip is woken up, the display subsystem is powered on, and the idle state of the system-on-chip chip includes the state of the system-on-chip chip when the screen is in sleep mode, and the wake-up operation does not include an unlocking operation.

12. The method according to any one of claims 1-5, 7-10, characterized in that: Before lowering the grayscale values ​​of the pixels in the screen according to the first ratio, the method further includes: the electronic device detecting that the electronic device is in a dark environment.

13. The method according to any one of claims 1-5, 7-10, characterized in that: The screen is an organic light emitting diode (OLED) screen.

14. The method according to claim 2 or 3, characterized in that: The method further comprises: After lowering the grayscale value of the pixels in the screen according to the first ratio, controlling the screen to display a first image at the first frame time, the first image being an image including indication information in the first frame displayed after the first time, the indication information being used to indicate that the electronic device is being unlocked; the indication information at least includes the fingerprint spot image; After the grayscale values ​​of the pixels in the screen are lowered according to the second ratio, the screen displays a second image in a second frame time, and the second image also includes the indication information.

15. The method according to claim 12, characterized in that Controlling the screen to display the first image during the first frame time specifically includes: The electronic device determines a first conduction voltage corresponding to the first pixel on the display channel through a first color correction curve and a grayscale value of the first pixel in the screen; wherein the first color correction curve is a color correction curve corresponding to a preset brightness in a group of color correction curves associated with a second screen refresh rate; the first pixel is a pixel in the screen whose grayscale value is reduced based on the second ratio, and the first pixel is used to display content other than the fingerprint spot image in the first image; the second screen refresh rate is a screen refresh rate of the screen when displaying the first image; The electronic device determines a second conduction voltage corresponding to a second pixel on a display channel according to the first grayscale value; the second pixel is used to display content in a fingerprint spot image; The on-state voltage of the first pixel on the display channel is controlled to be the first on-state voltage, and the on-state voltage of the second pixel on the display channel is controlled to be the second on-state voltage, so that the first pixel after being turned on displays the pixel corresponding to the first pixel in the first image, and the second pixel after being turned on displays the pixel corresponding to the second pixel in the first image.

16. An electronic device, characterized in that: include: One or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the electronic device to execute the method as described in any one of claims 1-15.

17. A computer-readable storage medium comprising computer instructions, characterized in that: When the computer instructions are executed on an electronic device, the electronic device is caused to execute the method as claimed in any one of claims 1 to 15.

18. A chip system, the chip system is applied to electronic equipment, characterized in that: The chip system includes one or more processors, and the processor is used to call computer instructions so that the electronic device executes the method as described in any one of claims 1-15.

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