Always-on display method and terminal

Abstract

The present application provides an always-on display method and a terminal. In the method, when a standard display mode is switched to a full-screen AOD mode, the terminal achieves a smooth transition by gradually reducing display brightness. Moreover, upon entering the full-screen AOD mode, a PWM dimming frequency and a screen refresh rate are also reduced to relatively low levels, thereby reducing power consumption. By implementing the technical solution provided by the present application, the visual abruptness caused by switching from the standard display mode to the full-screen AOD mode can be reduced, and the power consumption is also reduced in the full-screen AOD mode.

Description

Always-on display methods and terminals Technical Field

[0001] This application relates to the fields of terminals and image processing, and in particular to a method and terminal for always-on display. Background Technology

[0002] The always-on display (AOD) mode of a terminal allows the terminal to continue displaying information with low power consumption even when the screen is off. AOD modes include partial AOD and full-screen AOD. In partial AOD mode, after the screen is off, only a portion of the screen is used to display information; the information is usually concentrated on a part of the screen rather than the entire screen. Partial AOD mode can only display basic information, such as the time or the number of unread notifications, without showing too much detail. To display richer information, full-screen AOD mode was proposed. In full-screen AOD mode, after the screen is off, the entire screen can be used to display information, which can cover the entire screen from top to bottom, such as wallpaper and the time, notifications, etc., overlaid on the wallpaper.

[0003] In addition to AOD (Ahead-of-Demand) mode, the terminal also includes a standard display mode. In standard display mode, the terminal can display the main interface and receive user input for opening applications through the main interface. Alternatively, in standard display mode, in addition to displaying the main interface, the terminal can also display an unlock interface other than fingerprint unlock. When standard display mode is no longer needed, the terminal provides users with the ability to switch from standard display mode to AOD mode to meet different user needs.

[0004] However, the screen brightness differs between standard display mode and AOD display mode. How to naturally switch from standard display mode to AOD mode and reduce the visual abruptness caused to users by the difference in screen brightness is worth discussing.

[0005] Summary of the Invention

[0006] This application provides an always-on display method and terminal to offer a way to switch reasonably from a standard display mode to a full-screen AOD mode.

[0007] In a first aspect, embodiments of this application provide a screen-off display method, the method comprising: detecting a screen-off operation when a terminal displays a first user interface; the terminal displays a screen-off interface, and controls the screen brightness to be a first brightness at a first time and a second brightness at a second time; the first brightness is less than or equal to the screen brightness when the first user interface is displayed, and the first time is before the second time, the first brightness is greater than the second brightness.

[0008] In the above embodiments, the first time can be time a as described in the following embodiments, and the second time can be time b as described in the following embodiments. The first brightness can be brightness a as described in the following embodiments, and the second brightness can be brightness b as described in the following embodiments. The first user interface can be user interface 1 as described in the following embodiments, which can be regarded as the last frame of user interface displayed by the terminal in standard display mode.

[0009] Here, when the terminal switches from standard display mode to full-screen AOD mode, the screen brightness does not immediately drop to a dimmer (lower) second brightness level. Instead, at least one brighter (higher) brightness level is used as a transition brightness before the screen brightness drops to the dimmer second brightness level. Compared to directly controlling the screen brightness to a dimmer second brightness level after entering full-screen AOD mode, the method provided in the first aspect mentioned above can alleviate the user's abrupt visual experience when switching from a brighter standard display mode to full-screen AOD mode.

[0010] In conjunction with the first aspect, in some embodiments, controlling the screen brightness to be a first brightness at a first time and a second brightness at a second time specifically includes: from the first time to the second time, the terminal controls the screen brightness to gradually decrease from the first brightness to the second brightness; wherein, gradually decreasing from the first brightness to the second brightness means that there are M brightness levels between the first brightness and the second brightness, the M brightness levels being less than the first brightness and greater than the second brightness; and M being an integer greater than or equal to 1.

[0011] In the above embodiments, after entering full-screen AOD mode, the screen brightness is reduced to a dimmer second brightness level in order to save power consumption of the terminal in full-screen AOD mode. Gradually decreasing from a brighter first brightness level to a dimmer second brightness level achieves power saving while allowing the human eye to adapt to the change in screen brightness after entering full-screen AOD mode.

[0012] In conjunction with the first aspect, in some embodiments, when the first brightness, the M brightness levels, and the second brightness level are sorted in descending order of brightness, the brightness difference between the i-th brightness level and the (i-1)-th brightness level among the M+2 brightness levels is equal to the brightness difference between the i-th brightness level and the (i+1)-th brightness level, where i takes values ​​from 2 to M+1.

[0013] In the above embodiments, during the process of gradually decreasing from the first brightness to the second brightness, the brightness is controlled to decrease in a certain gradient, which can make the brightness decrease process smoother.

[0014] In conjunction with the first aspect, in some embodiments, the terminal remains on screen from the time the first user interface is displayed until the screen-off interface is displayed.

[0015] The above embodiment demonstrates that the switch from standard display mode to full-screen AOD mode does not involve a black screen as shown in Figure 1. This avoids the user perceiving two visual changes in screen brightness when transitioning from standard display mode to a black screen state and then from a black screen state to full-screen AOD mode. Specifically, the change from bright to dark is the first visual change caused by the transition from standard display mode to a black screen state, and the change from dark to low brightness is the second visual change caused by the transition from a black screen state to AOD mode.

[0016] In conjunction with the first aspect, in some embodiments, if the first brightness is less than the screen brightness when the screen is displaying the first user interface, the first time does not include the time when the first frame of the off-screen interface is displayed; or, if the first brightness is equal to the screen brightness when the screen is displaying the first user interface, the first time includes the time when the first frame of the off-screen interface is displayed.

[0017] In the above embodiments, if the first time includes the time when the first frame of the always-on display is displayed, then the first brightness can be regarded as brightness 1 in the following embodiments. If the first time does not include the time when the first frame of the always-on display is displayed, then the first brightness can be regarded as the brightness between brightness 1 and brightness 2 in the following embodiments.

[0018] In conjunction with the first aspect, in some embodiments, the method further includes: when the screen operates in pulse width modulation (PWM) dimming mode after displaying the off-screen interface, before the screen brightness drops to the second brightness, the frequency at which the terminal controls the screen to perform PWM dimming gradually decreases from a first dimming frequency to a second dimming frequency; the first dimming frequency is equal to the frequency at which the screen performs PWM dimming when displaying the first user interface; wherein, gradually decreasing from the first dimming frequency to the second dimming frequency means that there are Q dimming frequencies between the first dimming frequency and the second dimming frequency, the Q dimming frequencies being less than the first dimming frequency and greater than the second dimming frequency, and Q being an integer greater than or equal to 1.

[0019] In the above embodiments, the first dimming frequency can be dimming frequency 1 as described in the following embodiments, and the second dimming frequency can be dimming frequency 2 as described in the following embodiments.

[0020] Here, the terminal needs to stop reducing the dimming frequency before the screen brightness completely decreases. This way, while reducing the PWM dimming frequency to the second dimming frequency to save power, the brightness change caused by the frequency reduction can be masked by the brightness decrease. Furthermore, the PWM dimming frequency decreases gradually, so it won't affect the user's visual perception of the screen brightness reduction.

[0021] In conjunction with the first aspect, in some embodiments, after the screen brightness decreases to the second brightness, the method further includes: the frequency at which the terminal controls the screen to perform PWM dimming is the second dimming frequency.

[0022] In the above embodiment, after the second brightness level, the terminal controls the screen brightness to remain stable (the second brightness level). Simultaneously, the PWM dimming frequency is set to remain stable (the second dimming frequency).

[0023] In conjunction with the first aspect, in some embodiments, the method further includes: during the process of controlling the screen brightness to gradually decrease from the first brightness to the third brightness, the frequency at which the terminal controls the screen to perform PWM dimming is the first dimming frequency; the third brightness is greater than the second brightness.

[0024] In the above embodiments, the third brightness can be the brightness 3 involved in the following embodiments.

[0025] The reason for not reducing the dimming frequency during the initial period after the screen brightness begins to decrease includes: the initial time after switching from standard display mode to full-screen AOD mode, which involves not only changes in brightness (considered as changes in pixel color) but also significant changes in pixel content from displaying the first user interface to displaying the first frame of the off-screen image. Maintaining a high PWM dimming frequency during this initial period of brightness decrease is to suppress ghosting caused by large changes in pixel content within a short time, thus improving display quality.

[0026] In conjunction with the first aspect, in some embodiments, the method further includes: after the always-on display is shown and before the screen brightness drops to the second brightness, the terminal refreshes the screen using a first screen refresh rate.

[0027] In the above embodiments, the first screen refresh rate can be the screen refresh rate 1 involved in the following embodiments.

[0028] By keeping the screen refresh rate constant during the brightness reduction process, the screen brightness can be smoothly reduced to a dimmer second brightness.

[0029] In conjunction with the first aspect, in some embodiments, when the screen refresh rate of the terminal when displaying the first user interface is greater than or equal to the first preset refresh rate, the first screen refresh rate is equal to the screen refresh rate of the terminal when displaying the first user interface; when the refresh rate of the terminal when displaying the first user interface is less than the first preset refresh rate, the first screen refresh rate is equal to the first preset refresh rate.

[0030] In the above embodiments, the first preset refresh rate can be the preset screen refresh rate b involved in the following embodiments. This preset screen refresh rate is typically greater than or equal to 60Hz.

[0031] Here, a screen refresh rate greater than or equal to a first preset refresh rate when displaying the first user interface indicates that the screen refresh rate when displaying the first user interface is a dynamic refresh rate in standard display mode. Setting the first screen refresh rate to the dynamic refresh rate in standard display mode ensures that when switching from standard brightness mode to full-screen AOD mode, in addition to a smooth brightness decrease, the same screen refresh rate is maintained, so that visually sensitive users (a very small number of users) will not perceive any display changes due to the change in screen refresh rate.

[0032] In practice, it has been found that the initial screen refresh rate can be set to at least 60Hz, so the first preset refresh rate is usually 60Hz. For most users, when the initial screen refresh rate is greater than or equal to 60Hz and the brightness gradually decreases, even if the initial screen refresh rate differs from the screen refresh rate used to display the initial user interface, it is difficult to perceive the display change caused by the change in screen refresh rate, because the user's attention is mainly focused on the gradual decrease in brightness.

[0033] In conjunction with the first aspect, in some embodiments, after the screen brightness decreases to the second brightness, the method further includes: the terminal controlling the screen refresh rate to gradually decrease from the first screen refresh rate to the second screen refresh rate; the gradual decrease from the first screen refresh rate to the second screen refresh rate means that: the first screen refresh rate and the second screen refresh rate include X screen refresh rates, the X screen refresh rates being less than the first screen refresh rate and greater than the second screen refresh rate, where X is an integer greater than or equal to 1; the terminal controlling the screen refresh rate when the displayed content has not changed to a third screen refresh rate, and controlling the screen refresh rate when the displayed content changes to be equal to the second preset refresh rate; the third screen refresh rate is less than the second preset refresh rate and belongs to the refresh rates between the first screen refresh rate and the second screen refresh rate.

[0034] In the above embodiments, the second screen refresh rate can be screen refresh rate 2 as described in the following embodiments. The second preset refresh rate can be preset screen refresh rate a as described in the following embodiments. The third screen refresh rate can be screen refresh rate 3 as described in the following embodiments.

[0035] Here, controlling the screen refresh rate to gradually decrease is to prevent visual inconsistencies or misalignments in the always-on display caused by a large drop in the refresh rate gradient. Setting the screen refresh rate to a faster second preset refresh rate (e.g., 30Hz) when the displayed content changes is to ensure rapid screen refresh in dynamic refresh scenarios, achieving smooth display when the displayed content changes.

[0036] In conjunction with the first aspect, in some embodiments, the method further includes: when the always-on display is shown, the terminal responds to a user's touch of a fingerprint recognition area within the screen by increasing the screen brightness and the screen refresh rate.

[0037] In the above embodiments, increasing the screen refresh rate when fingerprint unlocking is detected is to better display animation effects (such as fingerprint light spots) in the unlocking scenario. Increasing the screen brightness is to transition from AOD mode to standard display mode.

[0038] In conjunction with the first aspect, in some embodiments, when the first ambient light brightness is less than the preset ambient light brightness, there is a first difference between the second brightness and the screen brightness when the first user interface is displayed; when the first ambient light brightness is greater than the preset ambient light brightness, there is a second difference between the second brightness and the screen brightness when the first user interface is displayed, and the second difference is greater than the first difference; the first ambient light brightness is equal to the ambient light brightness when the first user interface is displayed.

[0039] In the above embodiments, the first ambient light brightness can be the ambient light brightness 1 involved in the following embodiments. The first difference can be the difference 1 involved in the following embodiments. The second difference can be the difference 2 involved in the following embodiments.

[0040] The reason why the second difference is greater than the first difference is that: if the first ambient light brightness is less than the preset ambient light brightness, it means the ambient light is dark, and the display brightness when displaying the last frame of the user interface is at a relatively dark level. At this time, the second brightness is also at a relatively dark level, so the first difference is within a small range (threshold 1). However, if the first ambient light brightness is greater than the preset ambient light brightness, it means the ambient light is bright, and the display brightness when displaying the last frame of the user interface is at a relatively bright level. In order to take into account the principle of saving power after entering full-screen AOD mode, compared to the darker ambient light brightness, the second brightness can be increased under the brighter ambient light brightness, but it still cannot be too bright. Therefore, the second difference between the screen brightness and the second brightness when displaying the last frame of the user interface will be greater than threshold 1 but less than threshold 2.

[0041] In conjunction with the first aspect, in some embodiments, the method further includes: after the screen brightness decreases to the second brightness, the terminal adjusts the screen brightness based on the second ambient light brightness.

[0042] In the above embodiments, the second ambient light brightness can be the ambient light brightness 2 involved in the following embodiments.

[0043] Here, in full-screen AOD mode, after the screen brightness drops to the second lowest setting, it no longer gradually decreases. However, it still adjusts the screen brightness based on the ambient light level to ensure that the human eye can clearly see the always-on display under varying ambient light conditions.

[0044] In conjunction with the first aspect, in some embodiments, the method further includes: when displaying a user interface, the terminal controls the scanning time of a single row of screen pixels to be equal to 1 / (M × number of screen rows); where M is the screen refresh rate of the terminal when displaying the user interface and M is greater than a third preset refresh rate; when displaying a first screen-off interface, the terminal controls the scanning time of a single row of screen pixels to be equal to 1 / (M × number of screen rows); the interval between the start times of scanning two adjacent rows of screen pixels is equal to 1 / (W × number of screen rows), where W is the screen refresh rate of the terminal when displaying the first screen-off image.

[0045] In the above embodiments, maintaining a consistent scan time for each row of screen pixels helps improve display consistency, ensuring that different rows of screen pixels are updated within the same timeframe. This helps reduce screen brightness and color uniformity.

[0046] In conjunction with the first aspect, in some embodiments, the method further includes: when displaying a user interface, the terminal controls the time for a single screen refresh to be equal to 1 / M; where M is the screen refresh rate of the terminal when displaying the user interface and M is greater than a third preset refresh rate; when displaying a first screen-off interface, the terminal controls the time for a single screen refresh to be equal to 1 / M; the interval between the start times of two adjacent screen refreshes is equal to 1 / W; where W is the screen refresh rate of the terminal when displaying the first screen-off image.

[0047] In the above embodiments, setting the single screen refresh time after entering AOD mode to the same value can maintain the consistency of the screen-off interface refresh time, making the screen refresh process smooth and reducing visual discomfort caused by constantly changing screen refresh rates.

[0048] In conjunction with the first aspect, in some embodiments, the terminal controls the screen brightness of the screen to gradually decrease from a first brightness level to a second brightness level, specifically including: the terminal controls the transparency of the wallpaper layer in the always-on display to gradually decrease from a first transparency level to a second transparency level; the transparency of the upper layer of the wallpaper layer remains unchanged.

[0049] In the above embodiment, the content displayed on the always-on display includes the wallpaper and layers above the wallpaper (such as clock cards and message notification cards). Here, the brightness of the wallpaper is reduced, while the brightness of the layers above the wallpaper (such as clock cards and message notification cards) remains unchanged, at the first level of transparency. This results in the brightness of the layers above the wallpaper being greater than the brightness of the wallpaper. This helps to highlight the layers above the wallpaper, making it easier for users to notice them. For example, when a new message notification appears, the user is more likely to notice it.

[0050] In conjunction with the first aspect, in some embodiments, the terminal controls the screen brightness of the screen to gradually decrease from a first brightness level to a second brightness level, specifically including: the terminal controls the transparency of all layers in the off-screen interface to gradually decrease from a first transparency level to a second transparency level.

[0051] In the above embodiments, the brightness of both the wallpaper and the layer above it is reduced, which helps to save power consumption.

[0052] In conjunction with the first aspect, in some embodiments, the first screen refresh rate is greater than or equal to 60 Hz, and the second screen refresh rate includes one of 1 Hz to 10 Hz.

[0053] In a second aspect, embodiments of this application provide a terminal, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, the computer program code including computer instructions, and the one or more processors call the computer instructions to cause the terminal to perform the method implemented in the first aspect.

[0054] Thirdly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on a terminal, cause the terminal to perform the method as implemented in the first aspect.

[0055] Fourthly, embodiments of this application provide a chip system applied to a terminal. The chip system includes one or more processors that invoke computer instructions to cause the terminal to execute the method implemented in the first aspect. The chip system may be a system-on-chip (SoC). The processor may include a modem processor (also known as a modem or baseband chip).

[0056] Fifthly, embodiments of this application provide a computer program product containing instructions that, when run on a terminal, cause the terminal to execute the method as implemented in the first aspect.

[0057] It is understood that the terminal provided in the second aspect, the computer storage medium provided in the third aspect, the chip system provided in the fourth aspect, and the computer program product provided in the fifth aspect are all used to execute the methods provided in the embodiments of this application. Therefore, other beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding methods, and will not be repeated here. Attached Figure Description

[0058] Figure 1 shows a schematic diagram of a scenario in which a black screen is used to transition into AOD mode;

[0059] Figure 2 shows a schematic diagram of a scenario in which the brightness gradually decreases to transition into full-screen AOD mode in another scheme;

[0060] Figure 3 shows a schematic diagram of PWM dimming in the terminal;

[0061] Figure 4 illustrates a schematic diagram of the execution sequence for a reasonable power consumption reduction method;

[0062] Figure 5A shows a schematic diagram involving a single screen refresh;

[0063] Figure 5B shows another schematic diagram involving a single screen refresh;

[0064] Figure 6A shows a schematic diagram involving refreshing a row of screen pixels;

[0065] Figure 6B shows another schematic diagram involving refreshing a row of screen pixels;

[0066] Figure 7 illustrates a scenario where the brightness gradually increases to transition out of full-screen AOD mode;

[0067] Figure 8 illustrates the execution sequence of another reasonable power consumption reduction method;

[0068] Figure 9 illustrates an exemplary system framework diagram involved in switching from standard display mode to full-screen AOD mode via a display method;

[0069] Figure 10 illustrates an exemplary module interaction diagram involved in switching from standard display mode to full-screen AOD mode via a display method;

[0070] Figure 11 shows an exemplary graph of the gamma curve;

[0071] Figure 12 shows the basic structure and light-emitting principle of screen pixels;

[0072] Figure 13 shows a schematic diagram of the scanning time of a single row of screen pixels synchronized based on a basic structure display driver chip;

[0073] Figure 14 shows a comparison diagram of screen refresh and PWM dimming in standard display mode and full-screen AOD mode;

[0074] Figure 15 shows a schematic diagram of the processor's working status in standard display mode and full-screen AOD mode;

[0075] Figure 16 is a schematic diagram of the structure of the terminal provided in the embodiment of this application. Detailed Implementation

[0076] To save power, the screen brightness (brightness L1) needs to be at a lower level in AOD mode, typically lower than the screen brightness (brightness L2) in standard display mode. Therefore, when switching directly from standard display mode to AOD mode, the screen brightness suddenly changes from the higher brightness L2 to the lower brightness L1, causing screen flicker. Screen flicker can cause a sudden visual change for the user, leading to eye discomfort.

[0077] In one approach, a black screen is inserted between the standard display mode and the AOD mode to mitigate the user's visual abruptness. Using this black screen as a transition from the standard display mode to the AOD mode can alleviate the user's perception of visual abruptness.

[0078] As shown in Figure 1(1), in standard display mode, the terminal detects the operation of pressing the power button (a screen-off operation), which can trigger the terminal to switch from standard display mode to AOD mode. In response to the operation of pressing the power button, the terminal first enters a black screen state (as shown in Figure 1(2)). Then, it switches to AOD mode (as shown in Figure 1(3)).

[0079] It should be noted that entering AOD mode means that the terminal has entered a screen-off state. The interface displayed on the terminal in the screen-off state can be called the screen-off interface.

[0080] It should also be noted that in standard display mode, the terminal is in a screen-on state. The interface displayed on the terminal in standard display mode is also called the user interface. The user interface can include at least one of the following: the main interface, the application interface, and the unlock interface other than fingerprint unlock.

[0081] The aforementioned method of inserting a black screen effectively transforms the abrupt visual change caused by switching directly from standard display mode to AOD mode into two more user-friendly visual transitions. The first visual change is from standard display mode to a black screen. The second visual change is from a black screen to AOD mode. These two gradual transitions mitigate the abrupt visual change experienced when switching directly from standard display mode to AOD mode.

[0082] Compared to switching from standard display mode to global AOD mode, using the aforementioned method of inserting a black screen state to mitigate the abrupt visual change when switching from standard display mode to partial AOD mode is more effective. The reason for this is that the second visual change (the first visual change is the same) is relatively gradual: when switching from black screen to partial AOD mode, only a portion of the screen is illuminated to display information, while the un-displayed areas remain black. Therefore, the content of the interface doesn't change significantly, and the user's visual experience is minimal. However, when switching from black screen to global AOD mode, the entire screen is illuminated to display user information, resulting in a more noticeable visual change from dark to light.

[0083] In summary, when switching from standard display mode to global AOD mode using a black screen as a transition, there is still a visual change from bright to dark, and then from dark to low brightness. Specifically, the change from bright to dark is the first visual change caused by the transition from standard display mode to a black screen state, and the change from dark to low brightness is the second visual change caused by the transition from a black screen state to AOD mode.

[0084] It should be noted that "high brightness" does not mean that the screen brightness is very high in standard display mode, but only that the screen brightness is higher than in full-screen AOD mode.

[0085] To further reduce the abrupt visual change caused by switching from the standard display mode to the full-screen AOD mode, an always-on display method is proposed. In this method, as shown in Figure 2(1) and Figure 2(2), no black screen processing is performed when switching from the standard display mode to the full-screen AOD mode. Instead, the standard display mode is directly switched to the full-screen AOD mode while maintaining the screen on.

[0086] Referring again to Figure 2(2) and Figure 2(3), after the switch is completed, the terminal controls the screen brightness to gradually decrease from the higher brightness 1 to the lower brightness 2 during the screen refresh process. Here, brightness 1 is the screen brightness when the first frame of the always-on display is shown after the switch is completed. Brightness 2 can be regarded as the brightness L1 mentioned above, which is at a relatively dark brightness level. Here, the first frame of the always-on display does not specifically refer to the first frame of the always-on display, but refers to the first frame of the always-on display or the first few frames of the always-on display after entering AOD mode.

[0087] Here, "higher" does not refer to a high screen brightness when displaying the first frame of the always-on display, but rather that brightness 1 (the brightness when displaying the first frame of the always-on display) is brighter than brightness 2, and can be equal to the screen brightness when displaying the last frame of the user interface in standard display mode. This results in minimal or no brightness deviation when switching from standard display mode to full-screen AOD mode, avoiding screen flicker and mitigating the user's abrupt visual shock. Gradually decreasing brightness 1 to lower brightness 2 creates a smooth visual transition, making the transition from standard display mode to the darker full-screen AOD mode feel more natural and continuous. Compared to the aforementioned black screen processing, this gradual brightness reduction further minimizes the visual shock to the user's eyes, avoiding discomfort.

[0088] It should be noted that the "two values ​​equal to" in the embodiments of this application not only include two values ​​being the same, but also two values ​​being close to each other. "Close to each other" means that the difference between the two values ​​is within a small range, making it difficult for the user to perceive. For example, "Brightness 1 (the brightness when displaying the first frame of the always-on display) equal to the screen brightness when displaying the last frame of the user interface in standard display mode" can be expressed as: Brightness 1 is the same as the screen brightness when displaying the last frame of the user interface in standard display mode, or the difference between Brightness 1 and the screen brightness when displaying the last frame of the user interface in standard display mode is small, making it difficult for the user to perceive.

[0089] It should be noted that the last frame of the user interface and the first frame of the screen-off interface are displayed consecutively in terms of time.

[0090] It should also be noted that during the process of gradually decreasing the screen brightness (from brightness 1 to brightness 2), the brightness decrease gradient needs to be maintained at a reasonable level so that the user perceives the brightness decrease as continuous and smooth. Therefore, when gradually decreasing the screen brightness, the terminal needs to control the screen refresh rate at a relatively fast level (e.g., 60Hz) to meet the requirement of a smooth brightness decrease.

[0091] It should also be noted that after the terminal enters full-screen AOD mode, the entire screen can be used to display information. A reasonable full-screen AOD solution needs to minimize power consumption after entering full-screen AOD mode. The aforementioned method of reducing the screen brightness to a dimmer level after entering full-screen AOD mode is one way to reduce power consumption. In addition to reducing the screen brightness to a dimmer level, other ways to reduce power consumption include, but are not limited to, one or more of the following methods.

[0092] Power consumption reduction method 1: After entering full-screen AOD mode, the terminal switches the screen's touch event response mode from active mode in standard display mode to idle mode, thereby saving power by reducing the scanning frequency of touch events.

[0093] In active mode, the terminal scans touch operations at a high frequency and speed, the screen usually remains highly sensitive, and multi-touch (such as 10-finger touch) operations can usually be accurately recognized.

[0094] Compared to active mode, idle mode has a lower scanning frequency and speed, and relatively lower screen sensitivity. It typically supports single-point touch but not multi-point touch operation.

[0095] In full-screen AOD mode, although the device enters idle mode, it supports touch wake-up to balance power saving and response speed. After detecting a touch operation in idle mode, the device can switch to active mode. However, if no further touch operation is detected within a certain period after switching to active mode (e.g., 3 seconds), the device can control the screen to re-enter idle mode.

[0096] Power consumption reduction method 2: After entering full-screen AOD mode, the terminal gradually reduces the screen refresh rate from screen refresh rate 1 (the screen refresh rate during the brightness reduction process) to screen refresh rate 2. This screen refresh rate 2 is a lower level screen refresh rate, such as 1Hz, 2Hz, etc.

[0097] Furthermore, when the screen refresh rate drops to a value less than the preset screen refresh rate 'a' (screen refresh rate 3), the terminal controls the screen refresh rate to be 3 in static mode, and the screen refresh rate to be the preset screen refresh rate 'a' in dynamic mode. The static screen refresh rate includes the screen refresh rate when the displayed content remains unchanged. The dynamic screen refresh rate includes the screen refresh rate when the displayed content changes.

[0098] The changes in displayed content include: the content of the j-th frame of the always-on display to be displayed differs from that of the (j-1)-th frame of the always-on display that has already been displayed. For example, the clock may have changed, or notification messages may have been added or removed from the j-th frame compared to the (j-1)-th frame. The (j-1)-th frame of the always-on display is the frame preceding the j-th frame.

[0099] The displayed content remains unchanged, including: the content of the j-th frame of the screen to be displayed is the same as that of the (j-1)-th frame of the screen that has already been displayed.

[0100] Power Consumption Reduction Method 3: When the screen's first operating mode after entering full-screen AOD mode is pulse width modulation (PWM) dimming mode, the terminal gradually decreases the PWM dimming frequency from dimming frequency 1 to dimming frequency 2. Dimming frequency 1 is the dimming frequency used by the terminal in standard display mode when performing PWM dimming. Dimming frequency 1 is typically a relatively fast dimming frequency, such as 4320Hz. Dimming frequency 3 is a relatively low dimming frequency, such as 360Hz.

[0101] When the screen's first working mode after entering full-screen AOD mode is direct current (DC) dimming mode, the terminal can switch the screen's working mode from DC dimming mode to PWM dimming mode while in full-screen AOD mode. After that, the terminal will set the PWM dimming frequency to dimming frequency 2.

[0102] After entering full-screen AOD mode, you can refer to one of the following dimming mode determination methods to determine whether the screen's first working mode is PWM dimming mode or AOD dimming mode.

[0103] Dimming mode determination method 1: Determining screen brightness based on ambient light intensity. Ambient light intensity affects the human eye; the lower the ambient light, the lower the required display brightness to match visual perception. When the ambient light intensity is below a certain preset value, the display brightness is lower than the preset brightness. Therefore, after entering full-screen AOD mode, the screen's first operating mode is PWM dimming. When the ambient light intensity is high, exceeding a certain preset value, the display brightness is greater than the preset brightness. Therefore, after entering full-screen AOD mode, the screen's first operating mode is DC dimming. Here, ambient light intensity refers to the ambient light intensity detected when a screen-off operation is detected in standard display mode. Generally, ambient light intensity does not change drastically in a very short time. Therefore, the ambient light intensity detected when a screen-off operation is detected is also the ambient light intensity when displaying the last frame or a few frames of the user interface in standard display mode, and similarly, the ambient light intensity when displaying the first frame or a few frames of the screen-off interface.

[0104] The following describes the screen's working modes.

[0105] When a screen operates in DC dimming mode, it means that the terminal adjusts the screen's display brightness value (DBV) by controlling the intensity of the current input to the screen pixels. In DC dimming mode, the screen can maintain continuous brightness output and will not turn off.

[0106] When a screen operates in PWM dimming mode, it means that the device adjusts the screen's brightness by alternately turning the screen on and off. Compared to DC dimming mode, the screen in PWM dimming mode does not emit light continuously.

[0107] The dimming frequency in PWM dimming mode refers to the number of times the terminal can perform PWM dimming within one second. For example, a 360Hz dimming frequency means 360 PWM dimming cycles per second. Typically, the interval between the start times of two consecutive PWM dimming cycles is equal to 1 / 360 of a second. One PWM dimming cycle involves a brief period of screen off and then back on; the screen off time is extremely short and imperceptible to the user.

[0108] The time to complete one PWM dimming cycle is extremely short. Typically, multiple PWM dimming cycles can be completed while refreshing one frame of an image, thereby adjusting the display brightness. Let T1 be the time to refresh one frame of an image, and T2 be the interval between the start times of two adjacent PWM dimming cycles. Therefore, T1 / T2 PWM dimming cycles are performed while refreshing one frame of an image.

[0109] For example, referring to Figure 3, let's take a screen refresh rate of 120Hz and a PWM dimming frequency of 360Hz as an example. The time for a single screen refresh is 1 / 120s, and the interval between the start times of two adjacent PWM dimming cycles is 1 / 360s. Therefore, during one screen refresh, 3 (360 / 120) PWM dimming cycles will be performed evenly. The screen refresh is completed by scanning line by line. When displaying the h-th frame of the always-on display, the terminal refreshes the first 1 / 3 of the screen pixels in about 1 / 360s, and then performs one PWM dimming process (briefly turning off the entire screen and then turning it on again). Here, the content displayed after the first 1 / 3 of the screen pixels is refreshed is used to display the content of the h+1-th frame of the always-on display. At this time, the content displayed by the first 1 / 3 of the screen pixels is the content of the h+1-th frame of the always-on display, and the content displayed by the last 2 / 3 of the screen pixels is the h-th frame of the always-on display. After completing one PWM dimming cycle, the terminal continues to refresh line by line, and after approximately 1 / 360s, refreshes the middle third of the screen pixels to display the content of the (h+1)th frame's always-on display, then performs another PWM dimming process. After this second PWM dimming cycle, the terminal continues to refresh line by line, and after approximately 1 / 360s, refreshes the last third of the screen pixels to display the content of the (h+1)th frame's always-on display, then performs another PWM dimming process. Thus, three PWM dimming cycles are achieved during a single screen refresh. Subsequently, the terminal continues to refresh the screen, and PWM dimming continues during the refresh process.

[0110] Based on the foregoing introduction to DC dimming and PWM dimming modes, it can be explained that, typically, when the screen's actual brightness is lower than the preset brightness (lower brightness), it is difficult to reduce the screen's brightness to below the preset brightness (e.g., 90 nits) using DC dimming. Therefore, in this situation, the terminal will control the screen to operate in PWM dimming mode, which, by increasing the screen's off time, can achieve a lower actual brightness.

[0111] It's also important to clarify that display brightness differs from screen brightness, which was discussed earlier. Display brightness refers to the brightness level the screen can achieve when displaying an always-on display. Screen brightness, on the other hand, refers to the actual brightness level the screen displays when showing an always-on display. Screen brightness is a comprehensive measure of brightness, taking into account both display brightness and other factors. These other factors include, but are not limited to, one or more of the following: the brightness of the displayed content itself and the brightness performance of the screen's pixels. All other things being equal, adjusting display brightness also means adjusting screen brightness; higher display brightness results in higher screen brightness.

[0112] In some possible cases, using dimming mode determination method 1 also means that after entering AOD mode, the final screen brightness (i.e., the aforementioned brightness 2) as the screen brightness gradually decreases can be determined by the ambient light brightness 1. Generally speaking, the higher the ambient light brightness 1, the higher the brightness 2. In this case, if the ambient light brightness 1 is less than the preset ambient light brightness, there is a difference of 1 between brightness 2 and the screen brightness when displaying the last frame of the user interface. If the ambient light brightness 1 is greater than the preset ambient light brightness, there is a difference of 2 between brightness 2 and the screen brightness when displaying the last frame of the user interface, and this difference 2 is greater than the difference 1. Here, ambient light brightness 1 can be equal to the ambient light brightness when displaying the last frame of the user interface.

[0113] The reason why difference 2 is greater than difference 1 is as follows: When ambient light brightness 1 is less than the preset ambient light brightness, it indicates a darker ambient light. Therefore, the display brightness when showing the last frame of the user interface is at a relatively dark level, and brightness 2 is also at a relatively dark level. Thus, difference 1 is within a small range (threshold 1). However, when ambient light brightness 1 is greater than the preset ambient light brightness, it indicates a brighter ambient light. Therefore, the display brightness when showing the last frame of the user interface is at a relatively bright level. To balance power saving principles after entering full-screen AOD mode, brightness 2 can be increased in brighter ambient light conditions compared to darker ambient light conditions, but it still cannot be too bright. Therefore, the difference 2 between the screen brightness and brightness 2 when showing the last frame of the user interface will be greater than threshold 1 but less than threshold 2.

[0114] Dimming mode determination method 2: The display brightness can be at a lower level when the screen is off. This ensures that the screen brightness is also at a lower level. Therefore, the default operating mode after the screen enters AOD mode can be PWM dimming mode.

[0115] The operation of switching the screen's touch event response mode from active mode in the standard display mode to idle mode, as mentioned in the aforementioned power reduction method 1, does not affect the display effect. The touch event response mode can be set to idle mode when displaying the first frame of the always-on display.

[0116] However, the three power reduction methods mentioned above—controlling the screen brightness to gradually decrease to a dimmer level 2, power reduction method 2, and power reduction method 3—all directly affect the screen's display effect. A proper setting of the order in which these three power reduction methods are executed is necessary to achieve power saving while maintaining a good display effect after entering full-screen AOD mode (including the display effect when smoothly switching from standard display mode to full-screen AOD mode).

[0117] Figure 4 shows a schematic diagram of a reasonable power reduction method execution order. The following describes how to set the execution order of each power reduction method in conjunction with Figure 4.

[0118] The execution sequence may include: In the initial stage of entering full-screen AOD mode, the terminal first controls the screen brightness to gradually decrease from brightness 1 to brightness 2. After the screen brightness gradually decreases from brightness 1 to brightness 3, but before decreasing to brightness 2, the terminal gradually decreases the frequency of PWM dimming from dimming frequency 1 to dimming frequency 2 (power consumption reduction method 3). After the initial stage, the terminal begins to gradually reduce the screen refresh rate (power consumption reduction method 2).

[0119] The following describes the relevant content related to the aforementioned execution order.

[0120] First, let's describe the process of the terminal switching from standard display mode to full-screen AOD mode, including: Time 1, when the terminal detects a screen-off operation while displaying user interface 1 (the interface displayed in standard display mode). In response to this screen-off operation, the terminal displays a screen-off interface (indicating entry into full-screen AOD mode). From the display of user interface 1 until the display of the first frame of the screen-off interface, the terminal remains on. User interface 1 can be considered the last frame of the user interface displayed before entering full-screen AOD mode. Time 1 may also include the time spent displaying the last frame of the user interface.

[0121] To prevent flickering during the transition, the screen brightness (brightness 1) when displaying the first frame of the always-on display after entering full-screen AOD mode can be equal to the screen brightness at time 1. Then, in the initial stage of entering full-screen AOD mode, the terminal controls the screen brightness to gradually decrease from brightness 1 to brightness 2 (a dimmer screen brightness level). This allows for a smooth transition from the standard display mode to the full-screen AOD mode with a dimmer screen brightness level.

[0122] Referring to Figure 4, the terminal controls the screen brightness to gradually decrease from brightness 1 to brightness 2. This includes the initial stage of entering full-screen AOD mode, gradually reducing the wallpaper brightness. For example, the wallpaper's transparency (α) is gradually decreased (e.g., α decreases from 0 to 0.52) to achieve a decrease in wallpaper brightness, while the brightness of layers above the wallpaper (e.g., clock cards, message notification cards) remains unchanged. When the terminal decreases the wallpaper's transparency from 0 to 0.52 frame by frame, the difference in α between two consecutive frames of the screen-off interface is small (e.g., 0.2). The terminal can complete the gradual decrease in brightness within approximately 400ms, making the entire brightness decrease process fast and continuous. Here, α = 0 indicates that the wallpaper is completely transparent. The larger α is, the lower the wallpaper's transparency. The lower the wallpaper's transparency, the lower its brightness. It should be noted that after the wallpaper's transparency decreases to 0.52, the transparency of subsequent wallpapers can remain at 0.52. This keeps the screen brightness at a lower and more stable level, saving power while eliminating the need for further gradual brightness decreases.

[0123] Referring again to Figure 4, to make the brightness decrease process smoother, a relatively fast screen refresh rate 1 can be maintained during the brightness decrease. This screen refresh rate 1 is greater than or equal to the preset screen refresh rate b. The preset screen refresh rate b can be equal to a fast screen refresh rate such as 60Hz or 90Hz.

[0124] In some possible implementations, if the screen refresh rate at time 1 is greater than or equal to the preset screen refresh rate b (indicating that time 1 is dynamically refreshing), the terminal can set screen refresh rate 1 to be equal to the screen refresh rate at time 1. This way, when switching from standard brightness mode to full-screen AOD mode, in addition to achieving a smooth brightness decrease, the same screen refresh rate can be maintained, so that visually sensitive users (a very small number of users) will not perceive any display changes due to the change in screen refresh rate. If the screen refresh rate at time 1 is less than the preset screen refresh rate b, screen refresh rate 1 can be set to be equal to the screen refresh rate at time 1.

[0125] In practice, it has been found that the screen refresh rate 1 can be set to at least 60Hz. For most users, when the screen refresh rate 1 is greater than or equal to 60Hz and the brightness gradually decreases, even if the screen refresh rate 1 is different from the screen refresh rate of time 1, it is difficult to perceive the display change caused by the change in screen refresh rate, because the user's attention is mainly focused on the gradual decrease in brightness.

[0126] After the screen brightness gradually decreases from brightness 1 to brightness 3, but before it reaches brightness 2, the terminal lowers the PWM dimming frequency. This is because, after the initial brightness drops to a relatively low level (brightness 2), a reasonable design would be to maintain the screen brightness at brightness 2 without altering the human eye's light sensitivity. However, lowering the dimming frequency in PWM dimming mode affects screen brightness. If the displayed content remains unchanged, lowering the dimming frequency reduces the number of brief screen off cycles, leading to an increase in screen brightness. A significant increase in brightness can cause screen flickering. Therefore, gradually lowering the PWM dimming frequency from frequency 1 to frequency 2 needs to be performed after the screen brightness has started to decrease for a period of time, but continues gradually, using the gradual decrease in screen brightness to mask the brightness change caused by the decrease in the PWM dimming frequency. The reasons for not lowering the dimming frequency during the initial period of brightness decrease include: the initial time after switching from standard display mode to full-screen AOD mode, which involves not only changes in brightness (considered as changes in pixel color) but also significant changes in pixel content from displaying the last frame of the user interface to displaying the first frame of the off-screen image. At this point, maintaining the PWM dimming frequency at a relatively high level during the period when the brightness begins to decrease is to suppress the ghosting phenomenon caused by large changes in pixel content in a short period of time, thereby improving display quality.

[0127] It should be noted that, in some possible cases, the dimming frequency 1 gradually decreases to the dimming frequency 2, which means that there are Q dimming frequencies between dimming frequency 1 and dimming frequency 2. These Q dimming frequencies are less than dimming frequency 1 and greater than dimming frequency 2, where Q is an integer greater than or equal to 1.

[0128] Here, dimming frequency 1 is the frequency at which the terminal performs PWM dimming in standard display mode, or it can be understood as the frequency at which the terminal performs PWM dimming at time 1.

[0129] For example, referring to Figure 4, let's take a dimming frequency of 4320 Hz for frequency 1 and 360 Hz for frequency 2 as an example. During the first 200 ms of the initial phase, as the screen brightness gradually decreases from brightness 1 to brightness 3 (greater than brightness 2), the screen operates in PWM mode with a PWM dimming frequency of 4320 Hz. After the screen brightness decreases to brightness 3 but before decreasing to brightness 2, the terminal controls the screen to gradually decrease the PWM dimming frequency from 4320 Hz to 360 Hz. For example, it decreases from 4320 Hz to 2880 Hz, then from 2880 Hz to 1440 Hz, then from 1440 Hz to 720 Hz, and then gradually decreases from 720 Hz to 360 Hz. Furthermore, after the initial phase and before exiting full-screen AOD mode, the PWM dimming frequency remains at 360 Hz when the screen operates in PWM mode.

[0130] It should be noted that 0 in Figure 4 represents the start time when entering full-screen AOD mode. The 200ms in Figure 4 is an example, representing a short time after switching from standard display mode to full-screen AOD mode. It can also be 150ms, 100ms, etc., and this embodiment does not limit it.

[0131] It should also be noted that in the initial stage of entering full-screen AOD mode, the terminal screen can operate in both PWM dimming mode and DC dimming mode (not shown in Figure 4). For details on which mode it operates in, please refer to the description of the dimming mode determination method in the display documentation, which will not be repeated here.

[0132] The foregoing described the initial stage of entering AOD mode. When controlling the screen brightness to decrease, the terminal's screen refresh rate needs to be maintained at a high level, screen refresh rate 1. Therefore, the operation of gradually decreasing the screen refresh rate from screen refresh rate 1 to screen refresh rate 2 (a lower level) involved in the aforementioned power consumption reduction method 2 can occur after the initial stage.

[0133] It should be noted that, in some possible cases, a gradual decrease from screen refresh rate 1 to screen refresh rate 2 means that the terminal does not directly reduce the screen refresh rate from 1 to 2, but rather proceeds gradually. In this case, there are X screen refresh rates between screen refresh rate 1 and screen refresh rate 2, where X is an integer greater than or equal to 1.

[0134] For example, continuing to refer to Figure 4, with screen refresh rate 1 at 60Hz, after the initial stage, the terminal can first reduce the screen refresh rate from 60Hz to 30Hz, then to 10Hz, and then to 1Hz. Furthermore, when the screen refresh rate drops to a screen refresh rate 3 (e.g., 10Hz, 1Hz, etc. in Figure 4) that is less than the preset screen refresh rate a (e.g., 30Hz in Figure 4), the terminal controls the screen refresh rate to be 10Hz / 1Hz in static mode and 30Hz in dynamic mode.

[0135] It should be noted that the aforementioned screen refresh rates of 30Hz, 10Hz, and 1Hz are merely illustrative examples; other screen refresh rates are also possible, and this application does not limit this. The key is that the screen refresh rate decreases gradually to prevent visual inconsistencies or misalignments in the always-on display caused by a large drop in refresh rate. Setting the screen refresh rate to 30Hz during dynamic refresh is also an example; other values, such as 30Hz, are also possible. The goal is to maintain a relatively fast screen refresh rate so that it can respond to changes in the displayed content.

[0136] The screen refresh rate refers to the number of times a terminal can refresh its screen per second. For example, a 60Hz refresh rate means the screen refreshes its display 60 times per second. The interval between two consecutive refreshes is 1 / 60 of a second.

[0137] Generally, the time for a single screen refresh is equal to the reciprocal of the screen refresh rate. After entering AOD mode, when the screen refresh rate is W, the time it takes for the terminal to refresh the screen once to display one frame of the always-on display can be equal to 1 / W (a variable value), or it can be set to a fixed value, such as 1 / M or 1 / W1. Here, M is the screen refresh rate when the terminal displays the user interface at time 1, and M is greater than the preset screen refresh rate 3 (indicating that time 1 is dynamically refreshing). W1 is the screen refresh rate when the terminal displays the first frame of the always-on display (i.e., screen refresh rate 1).

[0138] In single-screen refresh mode 1, after entering AOD mode, when the screen refresh rate is W, the single-screen refresh time (the time required to refresh the screen once) is equal to 1 / W, and the interval between the start times of two adjacent screen refreshes is also equal to 1 / W. As shown in Figure 5A, when W = 120 Hz, the terminal can refresh the screen 120 times in 1 second. At this time, the terminal's single-screen refresh time is equal to 1 / 120 s, that is, the time required from the start of refreshing the first line of the screen to the end of refreshing the last line of the screen is equal to 1 / 120 s. For descriptions of other screen refresh rates (such as 60 Hz, 30 Hz, 10 Hz, and 1 Hz), please refer to the relevant content in Figure 5A and the description of 120 Hz, which will not be repeated here.

[0139] In single-screen refresh mode 2, after entering AOD mode, when the screen refresh rate is W, the terminal's single-screen refresh time is not equal to 1 / W but is set to a fixed single-screen refresh time (not changing with W). However, the interval between the start times of two adjacent screen refreshes is still equal to 1 / W. This fixed single-screen refresh time can be equal to the reciprocal of the screen refresh rate when displaying the first frame of the always-on display.

[0140] Alternatively, the fixed single screen refresh time can be synchronized with the single screen refresh time when the user interface is displayed at time 1 (equal to 1 / M). As shown in Figure 5B, taking M = 120 Hz as an example, when the user interface is displayed at time 1, the single screen refresh time is 1 / 120 s. After entering AOD mode, the synchronized single screen refresh time is 1 / 120, and the interval between the start times of two adjacent screen refreshes is still equal to 1 / W. For example, when W = 60 Hz, the interval between the start times of two adjacent screen refreshes is still equal to 1 / 60. The single screen refresh time in AOD mode is shortened by W / M compared to the unsynchronized 1 / W. For example, when W = 60 Hz, the synchronized single screen refresh time (1 / 120) is halved compared to the 1 / 60 before synchronization.

[0141] Here, as shown in Figure 5B, the interval between the start times of two adjacent screen refreshes is the interval between the time of the z-th screen refresh (e.g., refreshing the e-th frame) and the time of the (z+1)-th screen refresh (e.g., refreshing the e+1-th frame).

[0142] The advantages of single screen refresh mode 2 include: setting the single screen refresh time to the same value after entering AOD mode can maintain the consistency of the screen refresh time, making the screen refresh process smooth and reducing visual discomfort caused by constantly changing screen refresh rates.

[0143] The advantages of single-screen refresh method 1 include: it saves more power than single-screen refresh method 2. Referring to Figure 5B, within 1 second, when the single-screen refresh time is synchronized with 1 / M (single-screen refresh method 2), compared to when the single-screen refresh time is not synchronized with 1 / M (single-screen refresh method 1), the number of pulses input by the terminal to the screen in the same time is the same. However, a single pulse needs to make the screen pixel light up in a shorter time (e.g., 1 / 120s is shorter than 1 / 60s). Therefore, the single pulse of single-screen refresh method 2 is more "explosive" and consumes more power from the terminal.

[0144] The choice between single-screen refresh method 1 and single-screen refresh method 2 during a single screen refresh depends on the requirements. This application does not limit this.

[0145] Generally, the scan time for a single line of screen pixels is equal to the reciprocal of the screen refresh rate divided by the number of screen lines (or simply the number of lines). However, after entering AOD mode, the terminal can synchronize the scan time for a single line of screen pixels under different screen refresh rates to a fixed value. For example, 1 / (M × number of lines) or 1 / (W1 × number of lines). Here, M is the screen refresh rate when the terminal displays the user interface at time 1, and M is greater than the preset screen refresh rate 3. W1 is the screen refresh rate when the terminal displays the first frame of the always-on display.

[0146] After entering full-screen AOD mode, when the scanning time of a single row of screen pixels is synchronized to 1 / (M×number of rows), the interval between the start times of scanning two adjacent rows of screen pixels is equal to the time of a single screen refresh divided by the number of rows.

[0147] Maintaining consistent scan times for all rows of screen pixels helps improve display consistency, ensuring that pixels in different rows are updated within the same timeframe. This helps reduce screen brightness and color uniformity, thereby minimizing the mura effect.

[0148] This explanation uses the example of synchronizing the scan time of a single row of screen pixels to 1 / (120 × number of rows) s. Here, 1 / (120 × number of rows) s can be regarded as an exemplary scan time of a single row of screen pixels when the user interface is displayed at time 1.

[0149] As shown in Figure 6A, when the screen refresh rate is 120Hz, the scanning time for a single row of screen pixels (from the start of scanning one row of screen pixels to the end of scanning one row of screen pixels) is 1 / (120 × number of rows) s. When the screen refresh rate is 60Hz, the scanning time for a single row of screen pixels is synchronized with the 120Hz screen refresh rate at 1 / (120 × number of rows) s. Furthermore, when the time to complete a single screen refresh at 60Hz is 1 / 60Hz, the interval between the start times of scanning two adjacent rows of screen pixels is equal to 1 / (60 × number of rows) s.

[0150] Here, as shown in Figure 6A, the interval between the start times of scanning two adjacent rows of screen pixels is the interval between the start time of scanning the screen pixels of the y-th row (e.g., refreshing the 1st row) and the start time of scanning the screen pixels of the (y+1)-th row (e.g., refreshing the 1st row).

[0151] It should be noted that, continuing to refer to Figure 6A, when the scanning time of a single row of screen pixels is not synchronized and the screen refresh rate is 60 Hz, the scanning time of a single row of screen pixels should be 1 / (60 × number of rows) s.

[0152] After entering AOD mode, at screen refresh rates other than 60Hz, the terminal will synchronize the scanning time of a single row of screen pixels to 1 / (120 × number of rows) s. For example, referring to Figure 6B, when the screen refresh rate is 30Hz, the scanning time of a single row of screen pixels is synchronized with the 120Hz screen refresh rate to 1 / (120 × number of rows) s. Furthermore, when the time to complete a single screen refresh at 30Hz is 1 / 30 s, the interval between the start times of scanning two adjacent rows of screen pixels is equal to 1 / (30 × number of rows) s.

[0153] It should be noted that, continuing to refer to Figure 6B, when the scanning time of a single row of screen pixels is not synchronized and the screen refresh rate is 30 Hz, the scanning time of a single row of screen pixels should be 1 / (30 × number of rows) s.

[0154] At other screen refresh rates, the scanning time for a single line of screen pixels is synchronously 1 / (120 × number of lines) seconds. For details regarding terminal scanning of a single line of screen pixels at other screen refresh rates, please refer to the aforementioned descriptions; they will not be repeated here.

[0155] The preceding content described the transition and power consumption issues when switching from standard display mode to full-screen AOD mode. In practice, it has been found that a smooth transition is also required when switching from AOD mode to standard display mode. Referring again to Figure 4, when exiting full-screen AOD mode, the terminal can gradually increase the screen brightness (e.g., gradually increase the wallpaper brightness). When the brightness reaches a high level and it is determined that the screen can be unlocked, the user interface (indicating entry into standard display mode) will be displayed.

[0156] As shown in Figure 7(1), when the always-on display is displayed, an unlock operation is detected (e.g., the user touches the fingerprint recognition area on the screen). In response to this unlock operation, as shown in Figure 7(1), Figure 7(2), and Figure 7(3), the terminal gradually increases the screen brightness. When it is determined that unlocking is possible, referring to Figure 7(3) and Figure 7(4), the terminal switches from full-screen AOD mode to standard display mode.

[0157] When the terminal uses fingerprint unlocking, determining that it can be unlocked includes: collecting a fingerprint, and verifying that the fingerprint matches a pre-stored fingerprint.

[0158] When using fingerprint unlocking, in response to the unlocking operation, the terminal will also control the screen refresh rate at a higher level (such as 60hz, 90hz or 120hz, etc.) to facilitate the display of animation effects (such as fingerprint light spots) when unlocking.

[0159] It should be noted that the initial screen refresh rate (screen refresh rate 1) of 60Hz in the full-screen AOD mode in Figure 4 is a reasonable screen refresh rate obtained through practice. Besides 60Hz, screen refresh rate 1 can actually be other values. For example, to achieve a smoother transition effect, screen refresh rate 1 can be set to the screen refresh rate of time 1 (greater than or equal to the preset screen refresh rate b). For example, 120Hz will be used as an example.

[0160] Referring to Figure 8, the screen refresh rate is maintained at 120Hz during the initial stage of full-screen AOD mode. After the initial stage, the terminal controls the screen refresh rate to gradually decrease from 120Hz to 1Hz. For example, it first decreases from 120Hz to 60Hz, then from 60Hz to 30Hz, from 30Hz to 10Hz, and then from 10Hz to 1Hz. Furthermore, when the screen refresh rate decreases to below 30Hz, the dynamic screen refresh rate is controlled at 30Hz. Other operations after the terminal enters full-screen AOD mode as shown in Figure 8 can be referred to the aforementioned description of Figure 4, and will not be repeated here.

[0161] It should also be noted that the execution order of the power consumption reduction methods shown in Figure 4 is optional, and other execution orders may exist in practical applications. For example, the timing for the PWM dimming frequency to gradually decrease from dimming frequency 1 to dimming frequency 2 can occur after entering full-screen AOD and before the screen brightness decreases to brightness 2. That is, maintaining the PWM dimming frequency at dimming frequency 1 during the process of gradually decreasing brightness from 1 to 3 is optional.

[0162] In another embodiment, the aforementioned control of gradually decreasing the screen brightness from a higher brightness 1 to a lower brightness 2 when displaying an always-on display (AOD) is optional. In this additional embodiment, the terminal does not immediately reduce the screen brightness to a lower brightness (e.g., the aforementioned brightness L1 or brightness 2) after switching to full-screen AOD. Instead, it activates at least one higher brightness as a transition brightness when switching to full-screen AOD before reducing the screen brightness to a lower level. This mitigates the user's abrupt visual change. Here, "higher" does not mean brighter, but rather brighter relative to the lower brightness L1.

[0163] In this additional embodiment, the terminal detects a screen-off operation while displaying user interface 1 in standard display mode. In response to this screen-off operation, the terminal switches to full-screen AOD mode and displays the screen-off interface. The terminal controls the screen brightness to be brightness a at time a after switching to full-screen AOD, and brightness b at time b, which is less than brightness a. Time b occurs after time a.

[0164] After switching to full-screen AOD mode, the screen brightness decreases to the level before brightness b, which only includes brightness a. Brightness a is equal to the screen brightness when displaying user interface 1, or it can be equal to the aforementioned brightness 1. Brightness b is equivalent to the aforementioned brightness L1, or it can be equal to the aforementioned brightness 2.

[0165] After switching to full-screen AOD mode, if the screen brightness includes other brightness levels between brightness a and brightness b, it means that from time a to time b, the screen brightness gradually decreases from brightness a to brightness b. This allows for a gradual approach to achieving the dimmer brightness required in full-screen AOD mode.

[0166] At this time, the screen brightness of the terminal control screen at time 'a' after switching to full-screen AOD is brightness 'a', and the screen brightness at time 'b' is brightness 'b', which is less than brightness 'a'. This includes the screen brightness of the terminal control screen gradually decreasing from brightness 'a' to brightness 'b' from time 'a' to time 'b'. Here, "gradually decreasing from brightness 'a' to brightness 'b'" means that there are M brightness levels between brightness 'a' and brightness 'b', where these M brightness levels are less than brightness 'a' and greater than brightness 'b'. M is an integer greater than or equal to 1.

[0167] Here, to make the screen brightness decrease more smoothly from brightness a to brightness b, the terminal can control the screen brightness to decrease gradually from brightness a to brightness b according to a certain gradient. At this time, when brightness a, the M brightness values, and brightness b are sorted in descending order of brightness, the brightness difference between the i-th brightness value and the (i-1)-th brightness value among the M+2 brightness values ​​is equal to the brightness difference between the i-th brightness value and the (i+1)-th brightness value, where i takes values ​​from 2 to M+1.

[0168] If brightness a gradually decreases to brightness b, and if time a includes the time when the first frame of the always-on display is shown, then brightness a can be considered as brightness 1 as mentioned above. If the gradual decrease in brightness stops after brightness b, then brightness b can be considered as brightness 2 as mentioned above.

[0169] As brightness a gradually decreases to brightness b, if time a does not include the time spent displaying the first frame of the always-on display, then brightness a can be considered as the brightness between brightness 1 and brightness 2 mentioned above. If the brightness needs to continue decreasing after brightness b, then brightness b can be considered as the brightness between brightness 1 and brightness 2 mentioned above.

[0170] Based on the foregoing, it can be concluded that when brightness 'a' is less than the screen brightness when displaying user interface 1, time 'a' does not include the time spent displaying the first frame of the always-on display. Alternatively, when brightness 'a' is equal to the screen brightness when displaying user interface 1, time 'a' includes the time spent displaying the first frame of the always-on display.

[0171] In this additional embodiment, the terminal remains on until the screen-off interface is displayed after the terminal displays user interface 1.

[0172] Figure 9 illustrates an exemplary system framework diagram involved in switching from standard display mode to full-screen AOD mode via a display method.

[0173] Referring to Figure 9, the layered architecture divides the system into several layers, each with a clear role and function. Layers communicate with each other through interfaces. In some embodiments, the system framework is divided into five layers, from top to bottom: the application layer, the application framework layer, the hardware abstraction layer, the kernel layer, and the hardware layer.

[0174] The application layer can include a series of application packages (APKs).

[0175] As shown in Figure 9, the application layer may include a screen-off APK. This screen-off APK integrates AOD (Always-On Display) functionality and services, and can be used to detect screen-off operations to implement the aforementioned full-screen AOD mode. For example, the screen-off interface displayed on the terminal screen can be provided based on this screen-off APK.

[0176] The application framework layer includes services that can be called by the screen-off APK in response to screen-off operations.

[0177] As shown in Figure 9, the application framework layer may include sensor services, hardware always-on display brightness services, and power management services.

[0178] Referring to Figure 9(1), the hardware always-on display brightness service can be used to receive the command to enter full-screen AOD mode issued by the always-on display APK. Specifically, at time 1, the always-on display APK detects a screen-off operation when displaying user interface 1. In response to this screen-off operation, it issues a command to the hardware always-on display brightness service to enter full-screen AOD mode. Referring again to Figure 9(2), this command to enter full-screen AOD mode is used by the always-on display brightness service to register an ambient light sensor through the sensor service. This allows the ambient light data to be determined by the ambient light sensor after registration (as shown in Figure 9(3)). The ambient light data includes the ambient light brightness at time 1 (the aforementioned ambient light brightness 1).

[0179] The hardware always-on display brightness service is also used to trigger the execution of the content shown in Figure 9 (4a) and the content shown in Figure 9 (4b) after determining the ambient light brightness at time 1.

[0180] Referring to Figure 9(4a), the hardware-based always-on display brightness service determines the initial display brightness in full-screen AOD mode based on the ambient light brightness at time 1. It then sends a dimming command to the display driver IC (DDIC), which carries the initial display brightness. This initial display brightness, along with the α value discussed below, is used to control the screen brightness during the initial phase. For example, if the display brightness remains constant, a decrease in the α value will decrease the screen brightness.

[0181] Referring to Figure 9(4b), the hardware always-on display brightness service notifies the always-on display APK to send always-on display element information, including the α value (transparency value) applied to the wallpaper, to the synthesizer hardware abstraction module (belonging to the hardware abstraction layer). This α value is used to reduce the brightness of the wallpaper to achieve a gradual reduction in screen brightness in the initial stage.

[0182] After receiving the always-on display element information and the α value applied to the wallpaper, the synthesizer hardware abstraction module reduces the wallpaper's transparency based on the α value. Then, it synthesizes the always-on display with other always-on display elements (including clock cards, message notification cards, etc.) based on the wallpaper with reduced transparency. It should be noted that the transparency of the wallpaper in the first frame of the always-on display may not be reduced.

[0183] Then, the synthesizer hardware abstraction module sends the synthesized always-on display to the display driver chip located in the hardware layer through the digital rights management module (located in the kernel layer).

[0184] The display driver chip refreshes the screen using the dimming frequency, screen refresh rate, and the gamma curve corresponding to the display brightness to display the always-on display. The dimming frequency and screen refresh rate during the initial PWM dimming phase can be found in the aforementioned descriptions and will not be repeated here. The gamma curve corresponding to the display brightness is used to convert the grayscale values ​​of the image pixels in the always-on display into the brightness of the screen pixels. Details regarding the gamma curve and the detailed process of the display driver chip refreshing the screen in the initial phase can be found in the following descriptions of steps S105 and S106b, and will not be repeated here.

[0185] It's important to note that after the synthesizer hardware abstraction module synthesizes a frame of the always-on display based on the α value, it sends that frame to the display driver chip. After sending one frame, it synthesizes another frame based on the next α value and sends it to the display driver chip for display. This process is repeated to gradually decrease the screen brightness.

[0186] After a preset time (e.g., 200ms) has elapsed since step (4b) was executed, referring to Figure 9 (5), the screen-off APK sends a PWM dimming frequency reduction instruction to the power management service. Based on the foregoing, the condition for executing step (5) is that the first dimming mode adopted in the initial stage of the full-screen AOD mode is the PWM dimming mode. After receiving the PWM dimming frequency reduction instruction, the display driver chip will execute the aforementioned PWM dimming frequency reduction operation, including: gradually reducing the frequency of PWM dimming of the screen from dimming frequency 1 to dimming frequency 2 (e.g., gradually reducing from 4320 to 360). For details regarding this process, please refer to the description of step S106b below, which will not be repeated here.

[0187] After steps (4b) and (5) are completed, the operation of the aforementioned full-screen AOD mode in the initial stage is completed, and the processing flow after the initial stage begins. Referring to Figure 9 (6), the screen-off APK sends a screen refresh rate reduction instruction to the DDIC. After receiving the PWM dimming frequency reduction instruction, the display driver chip will execute the aforementioned screen refresh rate reduction operation, including: gradually decreasing the screen refresh rate from screen refresh rate 1 to screen refresh rate 2 (for example, gradually decreasing from 60Hz to 1Hz). For details regarding this process, please refer to the description of step S107b below, which will not be repeated here.

[0188] This completes the switch from standard display mode to full-screen AOD mode, and adjusts the parameters in full-screen AOD mode (such as screen refresh rate).

[0189] It should be noted that the system framework diagram shown in Figure 9 above and the description of each module involved in the system framework are only illustrative examples. In actual practice, there may be more or fewer modules than those shown in Figure 9. This application embodiment does not limit this.

[0190] Based on the system framework shown in Figure 9, the terminal can also switch from full-screen AOD mode to standard display mode (not shown in Figure 9). This process includes: the screen-off APK detects the unlock operation, sends a command to the compositor hardware abstraction module to increase screen brightness, and simultaneously sends a command to the display driver chip to increase the screen refresh rate. During the unlocking process, the screen brightness is gradually increased while the screen refresh rate remains relatively fast to facilitate the display of the fingerprint unlock animation. Upon confirmation of unlocking, the screen-off APK completes the unlocking process and notifies the relevant APKs in standard display mode to display the user interface.

[0191] Figure 10 illustrates an exemplary module interaction diagram involved in switching from standard display mode to full-screen AOD mode via a display method.

[0192] This process involves the screen, the screen-off APK, the hardware screen-off display brightness service, the synthesizer hardware abstraction module, and the display driver chip, as shown in Figure 9 above. A description of this process can be found in steps S101-S108 below.

[0193] S101. The terminal displays the user interface via the screen in standard display mode.

[0194] At time 1, when the terminal displays user interface 1, a screen-off operation is detected. This screen-off operation can be the operation of pressing the power button as shown in Figure 2 (1) above.

[0195] S102. In response to the screen-off operation, the screen-off APK sends a command to the hardware screen-off display brightness service to enter full-screen AOD mode.

[0196] Upon receiving a command to enter full-screen AOD mode, the hardware always-on display brightness service acquires ambient light data via an ambient light sensor, including the ambient light brightness at time 1.

[0197] S103a. Hardware Always-On Display Brightness Service determines the display brightness in AOD mode based on ambient light data.

[0198] The ambient light intensity at time 1 can be used to determine the display brightness in the initial stage.

[0199] The initial display brightness refers to the brightness level the screen can achieve when displaying the always-on display in the initial stage. It affects the initial screen brightness. However, the initial screen brightness is not only affected by the display brightness but also by the wallpaper's transparency (α). With the initial display brightness remaining constant, the lower the wallpaper's transparency, the lower the screen brightness.

[0200] Generally speaking, the higher the ambient light brightness at time 1, the greater the display brightness in the initial stage. However, in order to save power, when the ambient light brightness at time 1 is higher than a certain value, the display brightness in the initial stage can be controlled to be equal to a large display brightness (e.g., 500).

[0201] The initial display brightness includes the display brightness when displaying the first frame of the always-on display image. The higher the display brightness when displaying the first frame of the always-on display image, the higher the screen brightness (the aforementioned brightness 1) when displaying the first frame of the always-on display image will be, while also being equal to the screen brightness at time 1.

[0202] S104a. The screen-off APK sends screen-off interface element information to the synthesizer hardware abstraction module at time 1, including at least the α value applied to the wallpaper, and possibly card information such as a clock. The synthesizer hardware abstraction module lowers the wallpaper brightness through the α value, thereby synthesizing the screen-off interface.

[0203] The always-on display element information here includes the wallpaper and the layers displayed on top of the wallpaper (such as clock cards, message notification cards, etc.). The always-on display APK can be configured to apply an α value to the wallpaper to control the gradual decrease in the wallpaper's transparency.

[0204] The α value here can be a set of parameters recorded in the screen-off APK, for example, gradually decreasing from 0 to 0.52. Alternatively, as shown in step S103b (optional), the α value (transparency value) can be determined by the hardware screen-off display brightness service based on the display brightness in the initial stage; that is, the hardware screen-off display brightness service can determine the α value based on the display brightness in the initial stage. For example, the higher the display brightness in the initial stage, the faster the α value decreases.

[0205] The synthesizer hardware abstraction module sends the screen-off interface to the display driver chip N times. The α value used in the synthesis of the N sent screen-off interfaces is different. For example, the α value used in the synthesis of the N sent screen-off interfaces gradually increases, which makes the brightness of the synthesized screen-off interface gradually decrease, and further makes the screen brightness gradually decrease when displaying the screen-off interface.

[0206] It should be noted that step S104a is illustrated using the α value applied to the wallpaper layer as an example. Therefore, as the screen brightness gradually decreases, if the transparency of the upper layer of the wallpaper remains unchanged, then the brightness of the upper layer of the wallpaper also remains unchanged. The upper layer of the wallpaper includes other screen interface elements besides the wallpaper itself, such as clock cards and message notification cards.

[0207] In some other possible scenarios, step S104a can apply the α value to all layers in the always-on display, thus reducing the transparency of all content in the entire always-on display. This can also achieve the goal of gradually reducing the screen's display brightness.

[0208] S104b. The screen-off APK sends a dimming command carrying the display brightness to the display driver chip at time 1.

[0209] In the initial stage, the display brightness includes the display brightness during the initial stage.

[0210] In a method where screen brightness is gradually reduced by controlling the α value, the initial display brightness can be the same.

[0211] However, the aforementioned method of controlling the screen brightness to gradually decrease via the α value is optional. It's also possible to control the screen brightness to gradually decrease without using the α value. Instead, the screen brightness can be controlled to gradually decrease via the display brightness, while the wallpaper's α value remains unchanged. In this case, the display brightness determined by the terminal based on the ambient light brightness at time 1 is a gradually decreasing sequence of values, used to change (gradually decrease) the screen brightness by altering (gradually decreasing) the achievable brightness level.

[0212] S105. The display driver chip refreshes the screen to display the always-on display interface by using the screen refresh rate 1 and the gamma curve corresponding to the display brightness, and controls the screen brightness to gradually decrease to the first level based on the α value 1. When PWM dimming is performed during screen refresh, the PWM frequency is equal to the dimming frequency 1.

[0213] Here, an example of step S105 can be the content of the first 200ms of the initial stage shown in Figure 4 above, including: controlling the screen brightness to gradually decrease while keeping the screen refresh rate and PWM dimming frequency constant. Controlling the screen brightness to gradually decrease to a first level based on α value 1 includes: controlling the screen brightness to gradually decrease from brightness 1 to brightness 3 based on α value 1. This α value 1 is the first part of the α value. For a description of this process, please refer to the description of the relevant content in Figure 4 above, which will not be repeated here.

[0214] The gamma curve corresponding to the display brightness includes three sets of correspondences: the grayscale values ​​of the three channels (e.g., red / green / blue channels) of the image pixel and the corresponding on-state voltage (Vdata). Figure 11 shows an example correspondence between the grayscale value of one channel in the gamma curve and the corresponding on-state voltage (Vdata), used to map the grayscale value of the image pixel in that channel (which can be based on the color values ​​of the red / green / blue channels) to the brightness of the screen pixel in that channel. For example, if the image pixel corresponding to point A has a grayscale value of 250 in one channel, its brightness in gamma curve 21 is 30.

[0215] Here, Vdata is the brightness representation parameter of the grayscale value of the image pixel in the screen pixel. A screen pixel includes three sub-pixel units, and each sub-pixel unit has a Vdata, used to convert the grayscale values ​​of the three channels of the image pixel into brightness, thereby representing the brightness and color of the image based on the screen pixel. For details regarding Vdata and sub-pixel units, please refer to the description in step S107b below; it will not be repeated here.

[0216] It should be noted that when the screen is refreshed using the gamma curve corresponding to display brightness 1 to display the always-on display A, the display brightness of the always-on display A can reach the display brightness 1.

[0217] Typically, the gamma curve corresponding to the display brightness can be stored in the display driver chip, which records the gamma curves corresponding to different display brightness levels.

[0218] Dimming frequency 1 is the dimming frequency (e.g., 4320Hz) when the terminal performs PWM dimming in standard display mode. For a description of dimming frequency 1, please refer to the aforementioned content; it will not be repeated here.

[0219] The screen refresh rate 1 can be greater than or equal to the preset screen refresh rate b. For details regarding screen refresh rate 1 and the preset screen refresh rate b, please refer to the aforementioned content; they will not be repeated here.

[0220] It should be noted that after detecting the screen-off operation but before step S105 is executed, the display driver chip does not receive parameters for refreshing the screen in full-screen AOD mode (such as screen refresh rate). Therefore, the screen-off interface is not displayed, and the terminal remains in standard display mode. The user interface displayed in standard display mode at time 1 can be referred to as the last frame of the user interface displayed in standard display mode. The dimming frequency when the terminal performs PWM dimming at time 1 is the dimming frequency 1 mentioned above.

[0221] S106a. After time 1 plus a preset time, the screen-off APK sends a PWM dimming frequency reduction command to the display driver chip.

[0222] An example of this preset time could be 200ms, as shown in Figure 4 above.

[0223] This PWM dimming frequency reduction instruction is used to trigger the display driver chip to gradually reduce the dimming frequency after a preset time during the initial stage of PWM dimming, in order to save power consumption.

[0224] S106b. The display driver chip refreshes the screen through the screen refresh rate 1 and the gamma curve corresponding to the display brightness, and controls the screen brightness to gradually decrease from the first level to the second level based on the α value 2. When the screen performs PWM dimming, the PWM frequency is controlled to gradually decrease from the dimming frequency 1 to the dimming frequency 2.

[0225] Dimming frequency 1 is the dimming frequency used when performing PWM dimming at time 1. For details regarding dimming frequency 1, please refer to the previous description; it will not be repeated here.

[0226] Here, an example of step S106b can be the content from 200ms to 400ms in the initial stage shown in Figure 4 above, including: controlling the screen brightness to continue to gradually decrease while keeping the screen refresh rate constant, and simultaneously controlling the dimming frequency to decrease. Controlling the screen brightness to gradually decrease from the first level to the second level based on α value 2 includes: controlling the screen brightness to gradually decrease from the aforementioned brightness 3 to brightness 2 based on α value 2. This α value 2 is the latter part of the α value. A description of this process can be found in the aforementioned description of the relevant content in Figure 4, and will not be repeated here.

[0227] S107a. After steps S105 and S106b are completed, the screen-off APK sends a screen refresh rate reduction command to the display driver chip.

[0228] This screen refresh rate reduction instruction is used to trigger the display driver chip to gradually decrease the screen refresh rate after the initial stage, in order to save power consumption.

[0229] S107b. The display driver chip refreshes the screen to display the always-on display interface by using the gamma curve corresponding to the display brightness, and controls the screen refresh rate to gradually decrease from screen refresh rate 1 to screen refresh rate 2. When PWM dimming is performed during screen refresh, the PWM frequency is equal to the dimming frequency 1.

[0230] Here, an example of step S106b can be the content after the initial stage shown in Figure 4 above and before exiting the full-screen AOD mode, including: while keeping the frequency of PWM dimming unchanged, controlling the screen refresh rate to gradually decrease from screen refresh rate 1 to screen refresh rate 2.

[0231] It should be noted that during step S107b, the screen brightness stops gradually decreasing.

[0232] In some possible cases, the screen brightness can be maintained at brightness 2 after the initial phase. Methods for maintaining brightness 2 include: in full-screen AOD mode, wallpapers after the initial phase use the last α value used in the initial phase to lower the wallpaper's brightness.

[0233] It should be noted that in the aforementioned Figure 4, after the screen brightness drops to brightness 2 (after the initial stage), the influence of ambient light brightness on screen brightness is not reflected. In other possible cases, after the initial stage, the screen brightness can be adjusted according to the ambient light brightness after the initial stage (which can be referred to as ambient light brightness 2). If ambient light brightness 2 is higher than the ambient light brightness when it drops to brightness 2, then the screen brightness can be greater than brightness 2. If ambient light brightness 2 is lower than the ambient light brightness when it drops to brightness 2, then the screen brightness can be less than brightness 2. Refer to the aforementioned description of Figures 6A and 6B and their related contents. In step S107b, the display driver chip can control the scanning time of a single row of screen pixels at different screen refresh rates to be synchronized to 1 / (M × number of rows) or 1 / (W1 × number of rows). Where M is the screen refresh rate when the terminal displays the user interface at time 1. W1 is the screen refresh rate when the terminal displays the first frame of the off-screen interface (screen refresh rate 1), that is, the screen refresh rate when the terminal executes steps S105 and S106b.

[0234] This section first introduces the basic structure and light-emitting principle of screen pixels. Then, using this basic structure, it describes how the display driver chip synchronizes the scanning time of a single row of screen pixels.

[0235] A screen pixel has three sub-pixel units, each controlling the brightness of one of the three channels, enabling the screen pixel to achieve the corresponding brightness and color. This explanation uses one sub-pixel unit as an example; the other two sub-pixel units of this screen pixel have the same behavior, differing only in Vdata (on-state voltage), and will not be described in detail here.

[0236] Figure 12(1) shows a subpixel unit in a screen pixel, which is used to represent the brightness of a channel (e.g., one of the red, green or blue channels) in the screen pixel.

[0237] The sub-pixel unit includes transistors T1 to T7, and the light-emitting component OLED. Transistor T1 is a reset transistor, and transistors T7 and T8 are reset and compensation transistors. Transistors T2, T3, and T4 are driving transistors. Transistors T5 and T6 are light-emitting control transistors. The control terminal 1 (e.g., drain) of transistor T4 is electrically connected to the Vdata output terminal of the display driver chip to receive the Vdata output by the display driver chip. Vdata is determined by the aforementioned grayscale value and gamma curve. The larger the Vdata, the brighter the OLED becomes after it is turned on. The aforementioned reduction in screen brightness is actually achieved by changing this Vdata.

[0238] The display driver chip controls the transistors to turn on or off according to a certain timing sequence to update Vdata, thereby controlling the brightness of the sub-pixel units in each frame of the always-on display. As shown in Figure 12, the sub-pixel unit emits light based on Vdata1 at frame z. Then, the display driver chip scans the sub-pixel unit within a time interval equal to 1 / (refresh rate × number of lines) s (the time from the start of the scan to the end of the scan) to update Vdata1 to Vdata2. After the scan ends, the sub-pixel unit is controlled to emit light based on Vdata2 at frame z+1.

[0239] An exemplary process for updating Vdata1 to Vdata2 can be specifically referred to in steps (1)-(7) shown in Figure 12 (2).

[0240] In step (1), the display driver chip inputs a high-level signal to the control terminals (denoted as EM terminals) of transistors T5 and T6 to control the OLED of the sub-pixel unit to not emit light. The duration of this high-level signal is equal to 1 / (frequency refresh rate × number of lines) s. Then, in step (2), the display driver chip inputs a driving signal (denoted as Gate_N / Gate_P signal) to the control terminal 2 (denoted as Gate_P terminal) of transistor T4 and the control terminal (denoted as Gate_N terminal) of transistor T2 to control transistors T4, T2 and T3 to be in a conducting state. Then, in step (3), the display driver chip inputs a reset signal Vinit2 to the control terminal (denoted as Reset_H terminal) of transistor T7 and a reset signal Vinit3 to the control terminal (denoted as Reset_H terminal) of transistor T8 to control transistors T7 and T8 to be in a conducting state to eliminate the influence of Vdata1 on the OLED. Among them, the reset signal Vinit2 and the reset signal Vinit3 are the same, both of which are signals transmitted to the Reset_H terminal, denoted as Reset_H signal. Then, step (4) is executed, showing that the display driver chip inputs a reset signal Vinit1 (referred to as the Reset_P signal) to the control terminal (referred to as the Reset_P terminal) of transistor T1, controlling transistor T1 to be in the conducting state. The reset signal Vinit1 is transmitted to transistor T3 to set Vdata1 at transistor T3 to the initialized Vdata. Then, step (5) is executed, showing that the display driver chip inputs Vdata2 to the control terminal 1 (e.g., the drain) of transistor TT4, and transmits it to transistor T3 through transistor T2. Finally, step (6) is executed. The display driver chip inputs compensation signal Vinit2 to the control terminal of transistor T7 (denoted as Reset_H terminal) and compensation signal Vinit3 to the control terminal of transistor T8 (denoted as Reset_H terminal). This is used to eliminate the TFT (thin-film transistor) offset characteristics of the OLED (caused by losses from Vdata2 to transistor T3) and keep Vdata2 at transistor T3 the same as Vdata2 input by the display driver chip to transistor T4. Among them, compensation signal Vinit2 and compensation signal Vinit3 are the same and are both signals transmitted to the Reset_H terminal, denoted as Reset_H signal.

[0241] At this point, the OLED's on-state voltage is changed from Vdata1 to Vdata2. Then, step (7) is executed, which shows that the display driver chip inputs a low-level signal to the EM terminals of transistors T5 and T6 to control transistors T5 and T6 to be in the on state, so that the OLED emits light based on Vdata2 at the z+1 frame time.

[0242] It should be noted that the signals received by the EM terminal (high level or low level) can be collectively referred to as EM signals.

[0243] It should also be noted that when a row on the screen includes R screen pixels, it involves updating the Vdata of R×3 OLEDs. Their update method is completed by the display driver chip within 1 / (refresh rate × number of rows) seconds. The above is just an example of updating the Vdata of one OLED.

[0244] The following example illustrates how the display driver chip synchronizes the scanning time of a single row of screen pixels to 1 / (120 × number of rows) seconds. As shown in Figure 13, the h-th row of the screen includes R screen pixels. All pixels in the h-th row share a single EM signal (denoted as EM(h)), Gate_N / Gate_P signal (denoted as Gate_N / Gate_P(h)), Reset_H signal (denoted as Reset_H(h)), and Reset_P signal (denoted as Reset_H(P)). However, the Vdata of the R×3 OLEDs in row h are not shared. When the display driver chip scans row h, it scans R screen pixels within a time of 1 / (120×number of rows) s (the time from the start of scanning to the end of scanning). This scanning process is described in Figure 12(2) above. The updated Vdata (Vdata2) input by the display driver chip to transistor T4 of one sub-pixel unit is extended to the updated Vdata input to transistor T4 of R×3 sub-pixel units. The input timing of other signals remains unchanged. The interval between the start times of scanning two adjacent rows of screen pixels is equal to 1 / (W×number of screen rows), where W is the screen refresh rate when scanning screen pixels. After scanning row h, the display driver chip starts refreshing the R screen pixels in row h+1 after an interval of approximately 1 / (W×number of screen rows)-1 / (120×number of rows) s. The scanning process can be referred to as the process of scanning the screen pixels in row h above, except that h is replaced with h+1. It will not be described again here.

[0245] Here, the number of screen lines does not specifically refer to the number of rows of pixels on the screen from top to bottom. Rather, it refers to the number of scans during screen refresh. Referring to Figures 6A and 6B, one scan includes one start scan and one end scan.

[0246] In step S107b, when the display driver chip controls the scanning time of a single row of screen pixels at different screen refresh rates to be synchronously 1 / (M × number of rows) or 1 / (W1 × number of rows), it means that when refreshing the screen in steps S105 and S106b, the display driver chip also controls the scanning time of a single row of screen pixels to be 1 / (M × number of rows) or 1 / (W1 × number of rows). For related details, please refer to the descriptions of Figures 12 and 13 above; they will not be repeated here.

[0247] S108. When the screen refresh rate drops to a certain level, the display driver chip sets the screen refresh rate to be greater than or equal to the preset refresh rate when dynamically adjusting the screen refresh rate.

[0248] Step S108 includes: when the screen refresh rate drops to a screen refresh rate 3 (less than or equal to screen refresh rate 2, such as 10Hz, 1Hz, etc.) that is less than a preset screen refresh rate a (e.g., 30Hz), the terminal controls the static screen refresh rate to screen refresh rate 3 and the dynamic screen refresh rate to the preset screen refresh rate a. The static screen refresh rate includes the screen refresh rate when the displayed content does not change. The dynamic screen refresh rate includes the screen refresh rate when the displayed content changes.

[0249] Generally speaking, based on the description in Figure 4 above, the terminal can reduce the static screen refresh rate to 1Hz and the dynamic screen refresh rate to 30Hz in the early (short period) after entering AOD mode. In the later stages of full-screen AOD mode, the screen refresh rate will remain in this state, while the screen brightness and PWM dimming frequency will remain at a low level (e.g., 360Hz). In the later stages of full-screen AOD mode, the terminal consumes less power compared to standard display mode. The reason can be found in the following description of Figure 14.

[0250] Referring to Figure 14, in the later stages of full-screen AOD mode, the screen refresh rate is 1Hz when static, and the terminal refreshes the screen every 1 second, performing 360 PWM dimming cycles per second. In contrast, in standard display mode, the screen refresh rate can also be 1Hz when static, but 4320 PWM dimming cycles per second are performed. Therefore, in terms of PWM dimming frequency, the power consumption of full-screen AOD mode is lower than that of standard display mode when static.

[0251] In dynamic mode, the screen refresh rate is 30Hz, with the terminal refreshing the screen every 1 / 30th of a second and performing 12 PWM dimming cycles every 1 / 30th of a second. In contrast, in standard display mode, the screen refresh rate can reach up to 120Hz, with 36 PWM dimming cycles every 1 / 120th of a second. Therefore, considering the PWM dimming frequency and screen refresh rate, the power consumption of the dynamic full-screen AOD mode is lower than that of the standard display mode.

[0252] It should be noted that Figure 10 described above assumes the terminal's screen enters PWM dimming mode as its first operating mode after entering full-screen AOD. In reality, the terminal's screen can also enter DC mode as its first operating mode after entering full-screen AOD. In this case, the processing after entering full-screen AOD mode can still refer to Figure 10, except that the content related to PWM dimming is removed. However, in full-screen AOD mode, the screen's operating mode can be switched from DC dimming mode to PWM dimming mode. After switching to PWM dimming mode, the PWM dimming frequency is set to dimming frequency 2.

[0253] The timing for switching from DC dimming mode to PWM dimming mode includes: after entering the initial stage, when the ambient light brightness decreases and the screen display brightness decreases to the preset display brightness, switching from DC dimming mode to PWM dimming mode to achieve a lower display brightness.

[0254] It should also be noted that, in addition to the aforementioned power reduction methods, the terminal supports other power-saving operations in full-screen AOD mode. Referring to Figure 15, in standard display mode, the terminal supports responding to screen display control commands through the main processor's large and small cores. In full-screen display mode, when the screen refresh rate is high, the terminal supports responding to screen display control commands through the main processor's small cores or coprocessors. When the screen refresh rate is low, the processor can be in sleep mode, waking up to process commands when needed. A high screen refresh rate includes a screen refresh rate greater than or equal to the dynamic screen refresh rate. A low screen refresh rate includes a screen refresh rate less than the dynamic screen refresh rate.

[0255] Figure 16 is a schematic diagram of the structure of the terminal provided in the embodiment of this application.

[0256] The following description uses a terminal as an example to illustrate the embodiments. It should be understood that the terminal may have more or fewer components than those shown in Figure 16, may combine two or more components, or may have different component configurations. The various components shown in Figure 16 can be implemented in hardware, software, or a combination of hardware and software, including one or more signal processing and / or application-specific integrated circuits.

[0257] The terminal 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, a headphone jack 170D, a sensor module 180, buttons 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, a barometric pressure sensor 180C, a magnetic sensor 180D, an accelerometer sensor 180E, a distance sensor 180F, a proximity 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.

[0258] It is understood that the structures illustrated in the embodiments of this application do not constitute a specific limitation on the terminal. In other embodiments of this application, the terminal may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0259] Processor 110 may include one or more processing units, such as: application processor (AP), modem processor, graphics processing unit (GPU), image signal processor (ISP), controller, memory, video codec, digital signal processor (DSP), baseband processor, and / or neural network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors. The application processor (AP) in processor 110 may include the main processor shown in Figure 15.

[0260] The main processor and coprocessor shown in Figure 15 can be placed within the application processor. The main processor has superior processing power compared to the coprocessor. The main processor also includes large cores and small cores, with the large cores having superior processing power. In standard display mode, the terminal can respond to screen display commands through the large and small cores of the main processor, allowing for faster command response. In full-screen AOD mode, users typically do not operate the terminal or operate it infrequently; in this case, the terminal can maintain normal command response by calling the small cores or coprocessor to process commands.

[0261] In some embodiments, the processor 110 may include one or more interfaces. Interfaces may include inter-integrated circuit (I2C) interfaces, inter-integrated circuit sound (I2S) interfaces, pulse code modulation (PCM) interfaces, etc.

[0262] It is understood that the interface connection relationships between the modules illustrated in the embodiments of this application are merely illustrative and do not constitute a limitation on the structure of the terminal. In other embodiments of this application, the terminal may also adopt different interface connection methods or a combination of multiple interface connection methods as described in the above embodiments.

[0263] The terminal can achieve display functions through GPU, display screen 194, and application processor.

[0264] Display screen 194 is used to display images, videos, etc. Display screen 194 includes a display panel. The display panel can also be manufactured using organic light-emitting diodes (OLEDs), active-matrix organic light-emitting diodes (AMOLEDs), flexible light-emitting diodes (FLEDs), miniled, microled, micro-OLEDs, quantum dot light-emitting diodes (QLEDs), etc. In some embodiments, the terminal may include one or N displays 194, where N is a positive integer greater than 1. In some cases, the display screen may also be referred to as a screen or a touchscreen, etc.

[0265] In some embodiments, the display 194 may be a screen, such as an OLED screen.

[0266] The terminal can display functions through DDIC (not shown in Figure 16) and display screen 194.

[0267] The DDIC serves as the control core of the display screen 194, driving its operation and receiving data from the SOC (processor 110), such as image data and instructions. The DDIC can send drive signals and data to the display panel of the display screen 194 via electrical signals, thereby controlling screen brightness and color, enabling image information such as letters and pictures to be displayed on the screen, completing screen refresh, and allowing the display screen to refresh images according to the screen refresh rate.

[0268] The terminal can also achieve fingerprint unlocking function through system on chip (SOC), DDIC, display 194 and fingerprint sensor 180H.

[0269] The brightness adjustment method of OLED screens differs from that of LCD screens. OLED screen brightness is not adjusted by the screen backlight, but rather by controlling the brightness while simultaneously controlling the color of the screen pixels. Furthermore, when the screen brightness is below a preset brightness A (e.g., 75 nits), the OLED screen uses PWM dimming mode; when the screen brightness is above this preset brightness A, the OLED screen uses DC dimming mode. Typically, screen manufacturers 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 required to enter DC dimming.

[0270] Here, DC dimming mode changes screen brightness by increasing or decreasing circuit power. Changing voltage or current can change circuit power. PWM dimming mode does not rely on changing circuit power to change screen brightness, but rather on the screen's alternation between on and off states. That is, the screen does not emit light continuously, but alternates between being on and off. When the screen brightness decreases to a certain level, the changes in brightness of the three primary color pixels can no longer be represented as color changes, and color changes cannot be controlled. Therefore, OLED screens do not use DC dimming mode at low brightness, but instead use PWM dimming mode. This means that the actual current or voltage on the pixels is relatively high, and color expression is not affected. The perceived brightness value is changed by altering the duty cycle of the PWM. As shown in Figure 15 above, within one cycle, the more low-level signals, the larger the duty cycle. The more high-level signals, the smaller the duty cycle. When the duty cycle is 0, the OLED is neither conducting nor emitting light.

[0271] In some embodiments, the fingerprint sensor 180H may be disposed below the display screen 194, specifically below the fingerprint recognition area on the display screen 194 (also referred to as the screen).

[0272] Touch sensor 180K, also known as "touch panel". Touch sensor 180K can be set on display screen 194. Touch sensor 180K and display screen 194 together form touch screen, also known as "touch screen".

[0273] In some embodiments, the touch sensor 180K can be used to detect user actions on the fingerprint recognition area within the display screen 194 and transmit the detected touch action to the fingerprint sensor 180H to determine that the event corresponding to the touch action is a fingerprint unlock event (unlock event). The touch sensor 180K can also provide visual output related to the touch action through the display screen 194, such as displaying a fingerprint spot after the user places their finger on the fingerprint recognition area within the display screen 194.

[0274] In other embodiments, the touch sensor 180K may also be located on the surface of the terminal, in a different position than the display screen 194.

[0275] The ambient light sensor 180L can be used to sense the ambient light intensity. The terminal can adaptively adjust the brightness of the display screen 194 according to the sensed ambient light intensity.

[0276] In some embodiments, the ambient light sensor 180L can be used to detect whether the terminal is in the surrounding ambient light level.

[0277] The fingerprint sensor 180H can be a CMOS / CCD sensor, or even a fisheye-like camera. When a user places their finger on the fingerprint recognition area, the light emitted by the display 194 illuminates the finger, and the reflected light from the fingerprint shines through the screen onto the fingerprint sensor 180H beneath the display. During fingerprint unlocking, to more clearly illuminate the finger, the DDIC can control the display 194 to display a fingerprint spot with a high grayscale value (e.g., a grayscale value of 255) in the fingerprint recognition area. This fingerprint spot helps the fingerprint sensor 180H to capture a clear fingerprint. The SOC can compare the captured fingerprint with the registered fingerprint; if the captured fingerprint matches the registered fingerprint, the unlocking is confirmed to be successful.

[0278] In this embodiment of the application, the processor 110 can call computer instructions stored in the internal memory 121 to cause the terminal to execute the method in this embodiment of the application.

[0279] This application also provides a chip system, which includes at least one processor for implementing the functions involved in the terminal execution method in any of the above embodiments.

[0280] In one possible design, the chip system also includes a memory for storing program instructions and data, which may be located within or outside the processor.

[0281] The chip system can consist of chips or include chips and other discrete components.

[0282] Optionally, the chip system may contain one or more processors. These processors can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, an integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor, implemented by reading software code stored in memory.

[0283] Optionally, the chip system may contain one or more memories. These memories may be integrated with the processor or separated from it; this application does not limit the specific implementation.

[0284] For example, the memory can be a non-transient processor, such as a read-only memory (ROM), which can be integrated on the same chip as the processor or set on different chips. This application does not specifically limit the type of memory or the way the memory and processor are set.

[0285] For example, the chip system may 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 micro controller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0286] This application also provides a computer program product, the computer program product comprising: a computer program (also referred to as code or instructions), which, when the computer program is run, causes a computer to perform the method executed by the terminal in any of the above embodiments.

[0287] This application also provides a computer-readable storage medium storing a computer program (also referred to as code or instructions). When the computer program is run, it causes the computer to perform the method executed by the terminal in any of the above embodiments.

[0288] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0289] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0290] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions “a,” “an,” “the,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to and includes any or all possible combinations of one or more of the listed items.

[0291] The terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0292] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially 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, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. 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 integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state drive), etc.

[0293] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A method for displaying a screen when it is off, characterized in that, The method includes: A screen-off operation was detected when the terminal was displaying the first user interface; The terminal displays an off-screen interface and controls the screen brightness to be a first brightness at a first time and a second brightness at a second time; the first brightness is less than or equal to the screen brightness when the first user interface is displayed, the first time is before the second time, and the first brightness is greater than the second brightness.

2. The method according to claim 1, characterized in that, The screen brightness is controlled to be a first brightness at a first time and a second brightness at a second time, specifically including: From the first time point to the second time point, the terminal controls the screen brightness to gradually decrease from the first brightness level to the second brightness level; The phrase "gradually decreasing from the first brightness to the second brightness" indicates that there are M brightness levels between the first brightness and the second brightness, where each of the M brightness levels is less than the first brightness and greater than the second brightness; and M is an integer greater than or equal to 1.

3. The method according to claim 2, characterized in that, When the first brightness, the M brightness values, and the second brightness are sorted from largest to smallest, the brightness difference between the i-th brightness and the (i-1)-th brightness value in the M+2 brightness values ​​is equal to the brightness difference between the i-th brightness and the (i+1)-th brightness value, where i takes values ​​from 2 to M+1.

4. The method according to any one of claims 1-3, characterized in that, The terminal remains on until the first user interface is displayed and the screen-off interface is displayed.

5. The method according to any one of claims 1-4, characterized in that, If the first brightness is less than the screen brightness when the first user interface is displayed, the first time does not include the time when the first frame of the always-on display is displayed; or, if the first brightness is equal to the screen brightness when the first user interface is displayed, the first time includes the time when the first frame of the always-on display is displayed.

6. The method according to claim 2 or 3, characterized in that, The method further includes: When the screen operates in pulse width modulation (PWM) dimming mode after displaying the always-on interface, before the screen brightness drops to the second brightness, the frequency at which the terminal controls the screen to perform PWM dimming gradually decreases from the first dimming frequency to the second dimming frequency; the first dimming frequency is equal to the frequency at which the screen performs PWM dimming when displaying the first user interface. The phrase "gradually decreasing from the first dimming frequency to the second dimming frequency" indicates that there are Q dimming frequencies between the first dimming frequency and the second dimming frequency. These Q dimming frequencies are less than the first dimming frequency and greater than the second dimming frequency, and Q is an integer greater than or equal to 1.

7. The method according to claim 6, characterized in that, After the screen brightness decreases to the second brightness, the method further includes: The frequency at which the terminal controls the screen to perform PWM dimming is the second dimming frequency.

8. The method according to claim 6 or 7, characterized in that, The method further includes: During the process of controlling the screen brightness to gradually decrease from the first brightness to the third brightness, the frequency at which the terminal controls the screen to perform PWM dimming is the first dimming frequency; the third brightness is greater than the second brightness.

9. The method according to any one of claims 1-8, characterized in that, The method further includes: After the screen-off interface is displayed and before the screen brightness drops to the second brightness, the terminal refreshes the screen using the first screen refresh rate.

10. The method according to claim 9, characterized in that, When the screen refresh rate of the terminal is greater than or equal to the first preset refresh rate when displaying the first user interface, the first screen refresh rate is equal to the screen refresh rate of the terminal when displaying the first user interface. When the refresh rate of the terminal when displaying the first user interface is less than the first preset refresh rate, the first screen refresh rate is equal to the first preset refresh rate.

11. The method according to claim 9 or 10, characterized in that, After the screen brightness decreases to the second brightness, the method further includes: The terminal controls the screen refresh rate to gradually decrease from the first screen refresh rate to the second screen refresh rate; the gradual decrease from the first screen refresh rate to the second screen refresh rate means that there are X screen refresh rates between the first screen refresh rate and the second screen refresh rate, the X screen refresh rates are less than the first screen refresh rate and greater than the second screen refresh rate, and X is an integer greater than or equal to 1; The terminal controls the screen refresh rate to a third screen refresh rate when the displayed content does not change, and controls the screen refresh rate to be equal to the second preset refresh rate when the displayed content changes; the third screen refresh rate is less than the second preset refresh rate and belongs to the refresh rate that gradually decreases from the first screen refresh rate to the second screen refresh rate.

12. The method according to any one of claims 9-11, characterized in that, The method further includes: When the always-on display is shown, the terminal responds to the user's touch on the fingerprint recognition area within the screen by increasing the screen brightness and screen refresh rate.

13. The method according to any one of claims 1-12, characterized in that, When the first ambient light brightness is less than the preset ambient light brightness, there is a first difference between the second brightness and the screen brightness when displaying the first user interface; when the first ambient light brightness is greater than the preset ambient light brightness, there is a second difference between the second brightness and the screen brightness when displaying the first user interface, and the second difference is greater than the first difference. The first ambient light brightness is equal to the ambient light brightness when the first user interface is displayed.

14. The method according to claim 13, characterized in that, The method further includes: After the screen brightness drops to the second brightness level, the terminal adjusts the screen brightness based on the second ambient light brightness.

15. The method according to any one of claims 1-14, characterized in that, The method further includes: When displaying the user interface, the terminal controls the scanning time of a single row of screen pixels to be equal to 1 / (M × number of screen rows); M is the screen refresh rate when the terminal displays the user interface and M is greater than a third preset refresh rate; When the first screen-off interface is displayed, the terminal controls the scanning time of a single row of screen pixels to be equal to 1 / (M × number of screen rows); the interval between the start times of scanning two adjacent rows of screen pixels is equal to 1 / (W × number of screen rows), where W is the screen refresh rate of the terminal when displaying the first screen-off image.

16. The method according to any one of claims 1-15, characterized in that, The method further includes: When displaying the user interface, the terminal controls the screen refresh time to be equal to 1 / M; M is the screen refresh rate when the terminal displays the user interface and M is greater than a third preset refresh rate; When the first screen-off interface is displayed, the terminal controls the time for a single screen refresh to be equal to 1 / M; the interval between the start times of two adjacent screen refreshes is equal to 1 / W; where W is the screen refresh rate of the terminal when displaying the first screen-off image.

17. The method according to claim 2 or 3, characterized in that, The terminal controls the screen brightness to gradually decrease from a first brightness level to a second brightness level, specifically including: In the terminal control screen-off interface, the transparency of the wallpaper layer gradually decreases from a first level of transparency to a second level of transparency; the transparency of the layer above the wallpaper layer remains unchanged.

18. The method according to claim 2 or 3, characterized in that, The terminal controls the screen brightness to gradually decrease from a first brightness level to a second brightness level, specifically including: The transparency of all layers in the terminal control screen-off interface gradually decreases from the first level of transparency to the second level of transparency.

19. The method according to claim 11, characterized in that, The first screen refresh rate is greater than or equal to 60Hz, and the second screen refresh rate includes one of 1Hz to 10Hz.

20. A terminal, characterized in that, The terminal includes: 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 including computer instructions, and the one or more processors call the computer instructions to cause the terminal to perform the method as described in any one of claims 1 to 19.

21. A chip system, characterized in that, The chip system is applied to a terminal, and the chip system includes one or more processors, the processors being used to invoke computer instructions to cause the terminal to perform the method as described in any one of claims 1 to 19.

22. A computer-readable storage medium comprising instructions, characterized in that, When the instruction is executed on a terminal, the terminal causes the terminal to perform the method as described in any one of claims 1 to 19.

23. A computer program product containing instructions, characterized in that, When the computer program product is run on an electronic device, it causes the electronic device to perform the method as described in any one of claims 1-19.

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