Backlight adjusting method, medium and electronic device

Abstract

The present disclosure relates to a backlight adjusting method, which comprises the following steps: when rendering a current image, determining backlight data corresponding to the current image; when transmitting the current image, updating the backlight data corresponding to the current image to a backlight driving chip after a first preset time length of transmitting the current image; after the backlight data corresponding to the current image is updated, controlling the backlight driving chip to turn on a backlight source, and adjusting the brightness of the backlight source based on the backlight data of the current image. After the rendering and transmission of the current image and the calculation and updating of the backlight data thereof are completed, the backlight source is turned on, so that when the backlight source is turned on, the picture is displayed as the current image, and the backlight data is also the backlight data of the current image, thereby achieving the synchronization of the backlight and the picture display. The present disclosure further provides a medium and an electronic device for implementing the above-mentioned backlight adjusting method.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to a backlight adjustment method, medium, and electronic device. Background Technology

[0002] To achieve a three-dimensional display effect, the refresh rate of virtual reality devices is usually higher than that of ordinary monitors. The refresh rate of a display refers to the number of times the image on the screen is updated per second, and its unit is Hertz (Hz).

[0003] Because the backlight of a display is zoned, the backlight should be brighter in the brighter parts of the image and lower in the darker parts, thus improving the overall contrast. If the backlight and the image do not correspond, it will lead to reduced contrast and may even make the image look strange.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the problem of backlight not matching the image, and to provide a backlight adjustment method, medium and electronic device.

[0006] According to one aspect of this disclosure, a backlight adjustment method is provided, the method comprising: when rendering a current image, determining backlight data corresponding to the current image; when transmitting the current image, updating the backlight data corresponding to the current image to a backlight driver chip after transmitting the current image for a first preset time; and after the backlight data corresponding to the current image is updated, controlling the backlight driver chip to turn on the backlight source, and adjusting the backlight brightness based on the backlight data of the current image.

[0007] In one embodiment of this disclosure, the method further includes: determining the backlight brightness of the next frame of the current image based on the refresh rate of the current image.

[0008] In one embodiment of this disclosure, the method further includes: after the refresh rate of the current image is updated, compensating the backlight data of the current image, and using the compensated backlight data of the current image as the backlight data of the next frame of the current image.

[0009] In one embodiment of this disclosure, determining the backlight brightness of the next frame of the current image based on the refresh rate of the current image includes: acquiring the refresh rate of the screen; determining a compensation coefficient of the current image based on the refresh rate of the screen and a preset first correspondence relationship, wherein the first correspondence relationship is a correspondence relationship between different refresh rates and different compensation coefficients; compensating the backlight data of the current image based on the compensation coefficient of the current image; and determining the backlight brightness of the next frame of the current image based on the compensated backlight data of the current image.

[0010] In one embodiment of this disclosure, after the refresh rate of the current image is updated, the backlight data of the current image is compensated, and the compensated backlight data of the current image is used as the backlight data of the next frame of the current image. This includes: when the refresh rate of the screen changes, saving the updated compensation coefficient of the current image and setting a flag for updating the compensation coefficient; when the backlight of the current image is interrupted, updating the compensation coefficient of the current image based on the flag; determining the backlight data corresponding to the current image based on the compensation coefficient of the current image and updating the stored backlight data corresponding to the current image; clearing the flag after processing; and sending the backlight data corresponding to the current image when the backlight of the next frame of the current image is interrupted.

[0011] In one embodiment of this disclosure, determining the backlight brightness of the next frame of the current image based on the refresh rate of the current image includes: acquiring the refresh rate of the screen; updating the frequency of the pulse width modulation signal based on the refresh rate of the screen; and determining the backlight brightness of the next frame of the current image based on the updated frequency of the pulse width modulation signal.

[0012] In one embodiment of this disclosure, after the refresh rate of the current image is updated, the backlight data of the current image is compensated, and the compensated backlight data of the current image is used as the backlight data of the next frame of the current image. This includes: when the refresh rate of the image changes, saving the frequency of the pulse width modulation signal of the current image and setting a flag to update the frequency of the pulse width modulation signal; when the backlight of the current image is interrupted, updating the frequency of the pulse width modulation signal of the current image based on the flag; determining the backlight data corresponding to the current image based on the frequency of the pulse width modulation signal of the current image, updating the stored backlight data corresponding to the current image, and clearing the flag after processing; and when the backlight of the next frame of the current image is interrupted, sending the backlight data corresponding to the current image.

[0013] In one embodiment of this disclosure, when rendering the current image, determining the backlight data corresponding to the current image includes: acquiring an image of the eye and determining the eye's gaze area from the image; defining the gaze area in the current image as a high-definition area and the remaining area outside the gaze area in the current image as a non-high-definition area; using different layers for the high-definition area and the non-high-definition area; and using different rendering resolutions for different layers; calculating the backlight data for each rendered layer to obtain two backlight data sets, and combining the two backlight data sets into one set of backlight data.

[0014] In one embodiment of this disclosure, the method further includes: obtaining the rotation speed of the display device; and determining the refresh rate of the current image based on the rotation speed and a second correspondence, wherein the second correspondence is the correspondence between refresh rate levels and rotation speed ranges.

[0015] In one embodiment of this disclosure, the method further includes: determining the rendering resolution of the current image based on the rotation speed and a third correspondence, wherein the third correspondence is the correspondence between the scaling down of the rendering resolution and the rotation speed range.

[0016] In one embodiment of this disclosure, the rotational speed range in the second correspondence may be the same as or different from the rotational speed range in the third correspondence.

[0017] According to another aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method provided by any aspect of this disclosure.

[0018] According to another aspect of this disclosure, an electronic device is provided, including a processor and a memory, the memory being used to store executable instructions of the processor; wherein the processor is configured to perform a method implementing any aspect of this disclosure by executing the executable instructions.

[0019] In one embodiment of this disclosure, the electronic device further includes a display driver chip and a backlight driver chip; the processor includes an image processing module, a display driver module, a data processing module, and a backlight driver module; the image processing module is configured to render a current image; the data processing module is configured to determine backlight data corresponding to the current image when rendering the current image; the display driver module is configured to transmit the current image; the backlight driver module is configured to update the backlight data corresponding to the current image after transmitting the current image for a first preset time; the display driver chip is configured to receive the current image and display the current image on the display screen; the backlight driver chip is configured to receive the backlight data corresponding to the current image, and when the backlight data corresponding to the current image is updated, turn on the backlight source and adjust the backlight brightness based on the backlight data of the current image.

[0020] In one embodiment of this disclosure, the backlight driving module is further configured to determine the backlight brightness of the next frame of the current image based on the refresh rate of the current image.

[0021] The backlight adjustment method disclosed herein involves determining the backlight data corresponding to the current image during rendering; updating the backlight data corresponding to the current image to the backlight driver chip after a first preset transmission time during image transmission; and controlling the backlight driver chip to turn on the backlight source after the backlight data update is complete, adjusting the backlight brightness based on the backlight data of the current image. By turning on the backlight source only after completing the rendering and transmission of the current image, as well as the calculation and updating of its backlight data, the screen displays the current image when the backlight source is on, and the backlight data is also the backlight data of the current image, thereby achieving synchronization between backlight and screen display.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0024] Figure 1 This is a hardware connection block diagram of a display device according to an embodiment of the present disclosure.

[0025] Figure 2 The waveforms of the backlight signal and display signal involved in the embodiments of this disclosure are shown.

[0026] Figure 3 This is a flowchart illustrating a system operation of a display device according to an embodiment of this disclosure.

[0027] Figure 4 This is a flowchart of a backlight adjustment method according to an embodiment of the present disclosure.

[0028] Figure 5 This is a hardware connection block diagram of another display device according to an embodiment of this disclosure.

[0029] Figure 6 This is a schematic diagram illustrating a process involving a one-frame delay in updating backlight data according to an embodiment of this disclosure.

[0030] Figure 7 This is a schematic diagram illustrating another process involving a one-frame delay in updating backlight data according to an embodiment of this disclosure.

[0031] Figure 8 This is a schematic diagram illustrating the process of adjusting the backlight position according to the refresh rate in an embodiment of this disclosure.

[0032] Figure 9 This is a hardware connection block diagram of another display device according to an embodiment of the present disclosure.

[0033] Figure 10 This is another operational flowchart of a display device system according to an embodiment of this disclosure.

[0034] Figure 11 This is a flowchart illustrating the image differentiation layers and synthesis process involved in the embodiments of this disclosure.

[0035] Figure 12 This is a schematic diagram of the structure of an electronic device according to an embodiment of this disclosure.

[0036] In the diagram: 1-Processor, 2-Display screen, 21-First display screen, 22-Second display screen, 23-Display driver chip, 3-Backlight module, 31-First backlight module, 32-Second backlight module, 33-Backlight driver chip, 4-System, 41-Application program, 42-Screen display device, 421-Image processing module, 422-Display driver module, 43-Backlight adjustment device, 431-Data processing module, 432-Backlight driver module, 5-Pulse width modulation module, 6-Camera, 7-Gyroscope, 800-Electronic device, 810-Processing unit, 820-Storage unit, 821-Random access memory unit, 822-Cache memory unit, 823-Read-only memory unit, 824-Program / utility, 825-Program module, 830-Bus, 840-I / O interface, 850-Network adapter, 900-External device. Detailed Implementation

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0038] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0039] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0040] Display devices use local dimming, where each zone has its own brightness data. The brighter areas of the screen should have brighter backlighting, and the darker areas should have lower backlighting, thus improving overall image contrast. If the backlighting doesn't match the image brightness, it will reduce contrast and may even make the image look strange.

[0041] Based on this, the present disclosure provides a backlight adjustment method. For example... Figures 1 to 11 As shown, the method includes:

[0042] Step S10: When rendering the current image, determine the backlight data corresponding to the current image;

[0043] Step S20: When transmitting the current image, after transmitting the current image for a first preset time, update the backlight data corresponding to the current image to the backlight driver chip.

[0044] Step S30: After the backlight data corresponding to the current image is updated, control the backlight driver chip to turn on the backlight source and adjust the backlight brightness based on the backlight data of the current image.

[0045] After rendering and transmitting the current image, as well as calculating and updating its backlight data, the backlight is turned on. This ensures that when the backlight is on, the screen displays the current image, and the backlight data is also the backlight data of the current image, thus achieving synchronization between the backlight and the screen display.

[0046] The backlight adjustment method involved in the present disclosure will be described in detail below with reference to specific embodiments.

[0047] like Figure 1 As shown, the backlight of the display device is controlled by zones. The display device may include a processor 1, a display screen 2, and a backlight module 3. The backlight module 3 may include a backlight driver chip 33 and a backlight board. The display screen 2 and the processor 1 are connected via a Mobile Industry Processor Interface (MIPI). The processor 1 sends image data signals (mipi) transmitted via the MIPI protocol to the display screen 2. The display screen 2 receives the image data signals sent by the processor and feeds back a backlight on reference signal (TE) to the processor 1. The display screen sends a synchronization signal to the backlight driver chip 33. The backlight driver chip 33 receives the synchronization signal (vsync) sent by the display screen 2. After receiving the synchronization signal, the backlight driver chip 33 sends a backlight signal to the backlight source under internal timing control, and the backlight signal controls the backlight source to turn on. The processor 1 controls the backlight driver chip 33 through a Serial Peripheral Interface (SPI). Of course, the processor 1 and the backlight driver chip 33 can also be connected via an I2C interface.

[0048] The display device may include two displays 2 and two backlight modules 3. The two displays 2 are a first display 212 and a second display 222, and the two backlight modules 3 are a first backlight module 313 and a second backlight module 323. The processor 1 can perform image processing and display driving of the first display 212 through a first image data signal (MIPI1), and trigger the first backlight driver chip 33 of the first backlight module 313 to operate through a first synchronization signal (VSync1). The processor 1 can perform image processing and display driving of the second display 222 through a second image data signal (MIPI2), and trigger the second backlight driver chip 33 of the second backlight module 323 to operate through a second synchronization signal (VSync2).

[0049] like Figure 2As shown, the image data signal controls the timing of image transmission by processor 1. A low level indicates that processor 1 transmits an image to display driver chip 23, and a high level indicates a blanking area. The synchronization signal controls the timing of image refresh within display driver integrated circuit (DDIC) 23. A low level indicates image refresh, and a high level indicates a blanking area. The backlight on reference signal is generated by display driver chip 23. The rising edge of the backlight on reference signal is the backlight on reference time, and the falling edge of the backlight on reference signal is used as the interrupt trigger signal for backlight driver chip 33. The backlight signal controls the on and off of the backlight source. A high level indicates the backlight is on, and a low level indicates the backlight is off. The image data signal, synchronization signal, backlight on reference signal, and backlight signal together affect the synchronization of image display and backlight switching.

[0050] Generally, the image data signal and the synchronization signal are exactly the same. In virtual reality devices, if they are identical, the backlight will turn on before the image transmission is complete, and the liquid crystal will not have rotated to the correct position, resulting in motion blur. Therefore, the time from the rising edge of the synchronization signal to the rising edge of the backlight signal is the time allotted for the liquid crystal to rotate; this time is the liquid crystal's response speed. It is necessary to ensure that the backlight is at the end of the high-level region of the synchronization signal.

[0051] For example, the brightness value of each liquid crystal pixel ranges from 0 to 255, with different values ​​corresponding to different liquid crystal deflection angles. If the synchronization signal and the image data signal are consistent, the backlight on position remains unchanged, ending at the high level of the synchronization signal. The rising edge of the image data signal is approximately the time it takes for the last line of the image on the display screen to complete scanning. After scanning, the liquid crystal begins to deflect. The high level of the image data signal is short, for example, 1ms. The backlight turns on 1ms after the last line of the liquid crystal on the display screen has deflected. The backlight cannot deflect completely in 1ms. If a pixel's new brightness value is 100, and its original brightness value was 60, after 1ms, the brightness might only be 80, resulting in a discrepancy between the actual brightness value and the actual value.

[0052] Because backlighting is zoned—meaning the backlight is brighter in the brighter parts of the image and lower in the darker parts—this improves the overall contrast. If the backlight and the image don't correspond, it will reduce contrast and may even make the image look strange. Therefore, it's crucial to strictly control the consistency between the current image display and the backlight.

[0053] Therefore, in this embodiment, the rising edge of the synchronization signal of the current image is after the rising edge of the image data signal of the next frame of the current image and before the falling edge of the image data signal of the next frame of the current image; the falling edge of the synchronization signal of the current image is after the falling edge of the image data signal of the next frame of the current image and before the rising edge of the image data signal of the second frame image after the current image; the rising edge of the backlight on reference signal of the current image is after the rising edge of the synchronization signal of the current image; the falling edge of the backlight on reference signal of the current image is synchronized with the falling edge of the synchronization signal of the current image; the rising edge of the backlight signal of the current image is after the rising edge of the backlight on reference signal of the current image; and the falling edge of the backlight signal of the current image is synchronized with the falling edge of the backlight on reference signal of the current image.

[0054] like Figure 3 As shown, the processor 1 runs the application program 41, which can display the screen through the screen display device 42. The screen display device 42 includes an image processing module 421 and a display driver module 422. The image processing module 421 renders the current image based on the instructions of the application program 41 and transmits it to the display driver module 422. The display driver module 422 controls the display screen driver chip to display the rendered current image.

[0055] Processor 1 runs application program 41, which can adjust the backlight through backlight adjustment device 43. Backlight adjustment device 43 includes a data processing module 431 and a backlight driving module 432. The data processing module 431 calculates the backlight data corresponding to the current image and sends it to the backlight driving module 432. The backlight driving module 432 updates the backlight data corresponding to the current image to the backlight driving chip 33 and controls the backlight driving chip 33 to turn on the backlight. It should be noted that the data processing module 431 can use a software development kit (SDK).

[0056] Through such Figure 4The backlight adjustment method shown achieves consistency between screen display and backlight. In step S10, the image processing module 421 renders the current image, and the data processing module 431 determines the backlight data corresponding to the current image and sends it to the backlight driver module 432. In step S20, the image processing module 421 transmits the current image. After the falling edge of the backlight activation reference signal of the previous frame of the current image, the backlight driver module 432 refreshes the current image to the display screen and updates the backlight data corresponding to the current image to the backlight driver chip 33. The display driver module 422 refreshes the current image to the display driver chip. In step S30, before the falling edge of the backlight activation reference signal of the current image, the backlight driver module 432 controls the backlight driver chip to send the backlight signal of the current image, and adjusts the backlight brightness based on the backlight data of the current image. This ensures that when the backlight is on, the screen displays the current image, and the backlight data is also the backlight data of the current image, thereby achieving synchronization between backlight and screen display.

[0057] Understandably, the first preset duration is the time difference between the falling edge of the image data signal of the current image and the falling edge of the backlight activation reference signal of the previous frame of the current image. The time required for the backlight data of the current image to be updated is the time difference between the falling edge of the backlight activation reference signal of the previous frame of the current image and the falling edge of the backlight activation reference signal of the current image.

[0058] Specifically, in the low-level band of the first cycle of the image data signal, the current image is rendered and the backlight data corresponding to the rendered current image is determined; in the low-level band of the synchronization signal between the first and second moments, the previous frame of the current image is refreshed to the display screen; in the high-level band of the backlight signal between the first and second moments, the backlight is turned on and the previous frame of the current image is displayed.

[0059] The current image is transmitted in the low-level band of the second cycle of the image data signal, the next frame of the current image is rendered, and the backlight data corresponding to the next frame of the rendered current image is determined. When the synchronization signal is in the low-level band between the second and third moments, the current image is refreshed to the display screen. When the backlight signal is in the high-level band between the second and third moments, the backlight is turned on and the current image is displayed.

[0060] It should be noted that the first moment is the falling edge of the backlight activation reference signal of the second frame image preceding the current image, which triggers the first interruption of the backlight emission. The second moment is the falling edge of the backlight activation reference signal of the previous frame image, which triggers the second interruption of the backlight emission. The third moment is the falling edge of the backlight activation reference signal of the current image, which triggers the third interruption of the backlight emission.

[0061] It should be noted that the first cycle represents the time period for rendering the current image, and the second cycle represents the stage for rendering the next frame of the current image. The first and second cycles here only indicate the order, not a specific cycle of the image data signal; the second cycle immediately follows the first cycle. The first cycle can be the first cycle of the image data signal, and the second cycle can be the second cycle. Alternatively, the first cycle can be the third cycle, and the second cycle can be the fourth cycle.

[0062] like Figure 5 As shown, the display device may further include a pulse width modulation (PWM) module 5, which provides a pulse width modulation signal to the backlight module 3. Specifically, the pulse width modulation signal is transmitted to the backlight driver chip 33, which controls the backlight on-time in the current image based on the frequency of the pulse width modulation signal. For two displays 2 and two backlight modules 3, the processor 1 can control the pulse width modulation module 5 to provide pulse width modulation signals to the first backlight module 313 and the second backlight module 323 respectively.

[0063] The relationship between the frequency of the pulse width modulation (PWM) signal and the refresh rate (Frames Per Second, FPS) is: Pulse Width Modulation = 512 * Refresh Rate. As long as the frequency of the PWM signal is the same, the backlight on-time is the same. The PWM module 5 can be the power management integrated circuit (PMIC) in processor 1, or it can be an independent external module. When the refresh rate changes, the overall brightness of the backlight will change. Therefore, it is necessary to eliminate the influence of the refresh rate on the backlight brightness. Since the backlight brightness mainly depends on the brightness of the backlight source, it is necessary to control the brightness of the backlight source.

[0064] When the pulse width modulation module 5 is the power management integrated circuit (PMIC) in the processor 1, it cannot generate so many precise pulse width modulation signal frequencies. For variable refresh rates, a fixed pulse width modulation frequency can be used. During refresh rate switching, the display driver notifies the backlight driver module 432, which then performs corresponding processing based on the refresh rate. The backlight driver module 432 needs to compensate the backlight data and determine the backlight duration based on the compensated backlight data. When using an external pulse width modulation module 5, the external pulse width modulation module 5 can directly generate the required frequency to solve the backlight compensation problem.

[0065] When the frequency of the pulse width modulation signal is fixed, the backlight brightness control process is as follows: The refresh rate of the current image is obtained; the compensation coefficient γ of the current image is determined based on the refresh rate and a preset first correspondence, where the first correspondence is the correspondence between different refresh rates and different compensation coefficients; the backlight data of the current image is compensated so that the backlight driver chip 33 determines the backlight brightness based on the compensated backlight data of the current image. The first correspondence is shown in Table 1.

[0066] Table 1. Correspondence between refresh rate and compensation coefficient

[0067] refresh rate α0 α1 … αn compensation coefficient γ0 γ1 … γn

[0068] When the frequency of the pulse width modulation signal can be changed, the brightness control process of the backlight is as follows: obtain the refresh rate of the current image; update the frequency of the pulse width modulation signal based on the refresh rate of the current image; send the updated pulse width modulation signal to the backlight driver chip 33 so that the backlight driver chip 33 determines the brightness of the backlight according to the frequency of the updated pulse width modulation signal.

[0069] Regardless of the control method used, actual testing revealed that when the refresh rate changes, the human eye can perceive a momentary change in brightness, even though measurements showed almost no change in brightness before and after the refresh rate change. Experiments showed that delaying the backlight change by one frame effectively reduces the perceived brightness change.

[0070] Therefore, when the refresh rate of the current image is updated, the backlight compensation coefficient of the current image is updated one frame later.

[0071] like Figure 6 As shown, when a control method that compensates for backlight data is used, the delay process is as follows:

[0072] 1) When the screen refresh rate changes, save the updated compensation coefficient γ of the current image, and set the flag scal_need_update for updating the compensation coefficient to true.

[0073] 2) When the backlight of the current image is interrupted, update the compensation coefficient γ of the current image based on the flag scal_need_update.

[0074] 3) Determine the backlight data corresponding to the current image based on the compensation coefficient γ of the current image, update the stored backlight data corresponding to the current image, and clear the flag scal_need_update after processing.

[0075] 4) When the backlight is interrupted in the next frame of the current image, send the backlight data corresponding to the current image.

[0076] The backlight driver module has an interrupt handling function, a first callback function, and a second callback function. The interrupt handling function is used to update the compensation coefficient γ of the current image based on the flag scal_need_update when the backlight is interrupted in the current image. The interrupt handling function is also used to send the backlight data corresponding to the current image when the backlight is interrupted in the next frame of the current image.

[0077] The first callback function saves the updated compensation coefficient γ of the current image when the screen refresh rate changes, and sets the flag scal_need_update for updating the compensation coefficient to true. The second callback function determines the backlight data corresponding to the current image based on the compensation coefficient γ, updates the stored backlight data corresponding to the current image, and clears the flag scal_need_update after processing.

[0078] like Figure 7 As shown, when the frequency control method of the pulse width modulation signal is changed, the delay process is as follows:

[0079] 1) When the refresh rate of the screen changes, save the frequency of the pulse width modulation signal of the current image, and set the flag scal_need_update to true to update the frequency of the pulse width modulation signal.

[0080] 2) When the backlight of the current image is interrupted, update the frequency of the pulse width modulation signal of the current image based on the flag scal_need_update.

[0081] 3) Determine the backlight data corresponding to the current image based on the frequency of the pulse width modulation signal of the current image, update the stored backlight data corresponding to the current image, and clear the flag scal_need_update after processing.

[0082] 4) When the backlight is interrupted in the next frame of the current image, send the backlight data corresponding to the current image.

[0083] The backlight driver module has an interrupt handling function, a first callback function, and a second callback function. The first callback function, the interrupt handling function, updates the frequency of the pulse width modulation (PWM) signal for the current image based on the flag `scal_need_update` when the backlight is interrupted in the current image. The interrupt handling function also sends the backlight data corresponding to the current image when the backlight is interrupted in the next frame. The first callback function saves the frequency of the PWM signal for the current image and sets the flag `scal_need_update` to true when the refresh rate changes. The second callback function determines the backlight data corresponding to the current image based on the frequency of the PWM signal, updates the stored backlight data, and clears the flag `scal_need_update` after processing.

[0084] The two methods described above allow for a one-frame delay in updating the backlight data. When the screen refresh rate remains constant, the interrupt handler sends the backlight data after each backlight illumination interrupt. It should be noted that the falling edge of the backlight activation reference signal triggers the backlight illumination interrupt.

[0085] like Figure 8 As shown, even with dynamic refresh rates, it is still necessary to ensure that the backlight signal is at the end of the synchronization signal at all refresh rates. There is a response signal between the display driver chip 23 (Display Driver Integrated Circuit, DDIC) and the backlight driver chip 33, and the backlight is activated based on this response signal. When the application 41 changes the refresh rate, some registers need to be updated to adjust the position of this response signal, thereby changing the backlight position to meet the backlight requirements of that frame.

[0086] When the display device is a virtual display device, screen 2 requires a high refresh rate to reduce latency and dizziness. However, a high refresh rate also increases power consumption, significantly reducing the battery life of the virtual reality device. Different application modes are typically used, including but not limited to movie mode, normal mode, and game mode, each employing different refresh rates and rendering resolutions. It is worth considering correlating the rotation speed of the virtual reality device with the refresh rate and rendering resolution separately, determining the correspondence between different refresh rate levels and rotation speed ranges, as well as the correspondence between the reduction ratio of the rendering resolution and the rotation speed range.

[0087] The following explains the relationship between rotation speed and refresh rate. Different rotation speeds of the virtual reality device are set as V0, V1…Vn, and refresh rate levels are set as α0, α1,…αn. The correspondence between refresh rate levels and rotation speed zones is determined, as shown in Table 1.

[0088] Table 1. Correspondence between refresh rate levels and rotation speed zones

[0089] rotational speed V0—V1 V1—V2 … Vn-1—Vn refresh rate α0 α1 … αn

[0090] The following explains the relationship between rotation speed and rendering resolution. The rendering resolution is scaled down proportionally based on the rotation speed of the virtual reality device. For example, if the rendering resolution of display screen 2 is R0, R0 is scaled down by 0.9 to become R1 (both length and width are scaled down to 0.9 of their original values), and R0 is scaled down by 0.8 to become R2. This process continues, dividing the rendering resolution into R1…Rn according to the scaling down ratio. The correspondence between the scaling down ratio of the rendering resolution and the rotation speed range is determined, as shown in Table 2.

[0091] Table 2 shows the correspondence between the reduction ratio of rendering resolution and the rotation speed range.

[0092] rotational speed V0—V1 V1—V2 … Vn-1—Vn Rendering resolution R0 R1 … Rn

[0093] The second correspondence is defined as the relationship between refresh rate levels and rotation speed ranges, and the third correspondence is defined as the relationship between the reduction ratio of rendering resolution and rotation speed ranges. The rotation speed ranges in the second and third correspondences may be the same or different. For example, as shown in Tables 1 and 2, the speed ranges corresponding to α0 and R0 can both be V0–V1; or the speed range corresponding to α0 can be V0–V1, and the speed range corresponding to R0 can be V0–V2.

[0094] In viewing mode, the screen does not rotate with the head; a fixed refresh rate and rendering resolution are used. In normal mode, a standard mapping is used. In game mode, which is sensitive to refresh rate, a higher refresh rate is used in the mapping table compared to normal mode. The gyroscope 7 can be controlled to obtain the rotation speed of the virtual reality device; the refresh rate of the current image is determined based on the rotation speed and a second mapping. The rendering resolution of the current image is determined based on the rotation speed and a third mapping. This determines the refresh rate and rendering resolution of the current image in the virtual reality device for different modes.

[0095] The refresh rate is switched based on the rotation speed obtained from the gyroscope 7 to save power as much as possible while maintaining the viewing experience. For example, in game mode, when head movements are rapid, the virtual reality device's screen will follow the head's rapid rotation; therefore, the overall rendering resolution of the screen can be appropriately reduced. Figure 9 As shown, the display device may also include a gyroscope 7, through which the processor 1 acquires measurement data and calculates the rotation speed of the virtual display device.

[0096] like Figure 9 As shown, the display device may also include a camera 6, and the processor 1 controls the camera 6 to capture images of the eyes. Using a gaze point algorithm, the gaze area of ​​the current image is determined on the display screen 2. The virtual reality device can be a VR headset, and the camera 6 can be placed inside the VR headset. The gaze area of ​​the current image is defined as the high-definition area, and the remaining area outside the gaze area is defined as the non-high-definition area. The high-definition and non-high-definition areas use different rendering resolutions.

[0097] Because rendering requires the use of a Graphics Processing Unit (GPU), the higher the rendering resolution of the current image, the greater the resource consumption and power consumption of the GPU. Non-high-definition areas do not need to be very clear, as they are only visible in the peripheral vision, thus using a lower rendering resolution, thereby reducing the overall resource consumption and power consumption of the GPU.

[0098] like Figure 10 and Figure 11 As shown, the displayed screen is typically composed of various layers, and System 4 ultimately combines these layers into a single image. Generally, the main screen of System 4 has only one layer. Taking the current image as an example, the high-resolution and low-resolution areas of the current image are represented by two different layers. The high-resolution area corresponds to the first sub-image, and the low-resolution area corresponds to the second sub-image. This allows for rendering of the two different layers at different resolutions, and the rendered layers are then combined into a single image, which is the current image. It should be noted that "system" here refers to the operating system, which could be Android, Windows, or iOS.

[0099] High-definition and non-high-definition areas use two different layers, resulting in two sub-images after rendering. These two sub-images are processed using different algorithms to obtain two sets of backlight data, which are then combined into a single set of backlight data. Since the backlight of display 2 is zoned, a local dimming algorithm is used to determine the backlight data for different areas of display 2. The local dimming algorithm has two versions: a fine version and a coarse version. The fine version is more time-consuming but provides more accurate results, while the coarse version is faster but less accurate. The high-definition area uses the fine version algorithm, and the non-high-definition area uses the coarse version algorithm. This reduces the overall backlight data calculation time and the consumption of CPU 1 resources, thereby reducing power consumption.

[0100] When the refresh rate changes, the display driver module 422 notifies the backlight driver module 432. Based on the refresh rate change, the backlight driver module 432 adjusts the compensation coefficient γ or the frequency of the pulse width modulation signal accordingly, thereby changing the brightness of the backlight.

[0101] Exemplary embodiments of this disclosure also provide a computer-readable storage medium that can be implemented as a program product including program code, which, when run on an electronic device, causes the electronic device to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure. In one embodiment, the program product can be implemented as a portable compact disc read-only memory (CD-ROM) including program code and can run on an electronic device, such as a personal computer. However, the program product of this disclosure is not limited thereto. In this document, the readable storage medium can be any tangible medium that contains or stores a program that can be used or combined with an instruction execution system, apparatus, or device.

[0102] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0103] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0104] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0105] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0106] like Figure 12 As shown, the electronic device 800 is presented in the form of a general-purpose computing device. The components of the electronic device 800 may include, but are not limited to: at least one processing unit 810, at least one storage unit 820, and a bus 830 connecting different system components (including storage unit 820 and processing unit 810).

[0107] The storage unit stores program code, which can be executed by the processing unit 810 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of the present invention. For example, the processing unit 810 can perform actions such as... Figure 4 The methods and steps shown are as follows.

[0108] Storage unit 820 may include volatile storage units, such as random access memory (RAM) 821 and / or cache memory 822, and may further include read-only memory (ROM) 823.

[0109] The storage unit 820 may also include a program / utility 824 having a set (at least one) of program modules 825, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0110] Bus 830 may include a data bus, an address bus, and a control bus.

[0111] Electronic device 800 can also communicate with one or more external devices 900 (e.g., keyboards, pointing devices, Bluetooth devices, etc.) via input / output (I / O) interface 840. Electronic device 800 can also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via network adapter 850. As shown, network adapter 850 communicates with other modules of electronic device 800 via bus 830. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 800, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0112] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to exemplary embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0113] Those skilled in the art will understand that various aspects of this disclosure can be implemented as systems, methods, or program products. Therefore, various aspects of this disclosure can be embodied in entirely hardware implementations, entirely software implementations (including firmware, microcode, etc.), or implementations combining hardware and software aspects, collectively referred to herein as “circuit,” “module,” or “system.” Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0114] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is defined only by the appended claims.

Claims

1. A backlight adjustment method, characterized in that, The method includes: When rendering the current image, determine the backlight data corresponding to the current image; When transmitting the current image, after transmitting the current image for a first preset time, the backlight data corresponding to the current image is updated to the backlight driver chip; Once the backlight data corresponding to the current image is updated, the backlight driver chip is controlled to turn on the backlight source, and the backlight brightness is adjusted based on the backlight data of the current image. The backlight brightness of the next frame of the current image is determined based on the refresh rate of the current image. After the refresh rate of the current image is updated, the backlight data of the current image is compensated, and the compensated backlight data of the current image is used as the backlight data of the next frame of the current image.

2. The backlight adjustment method according to claim 1, characterized in that, Determining the backlight brightness of the next frame of the current image based on the refresh rate of the current image includes: Get the screen refresh rate; The compensation coefficient of the current image is determined based on the refresh rate of the image and a preset first correspondence, wherein the first correspondence is the correspondence between different refresh rates and different compensation coefficients. The backlight data of the current image is compensated based on the compensation coefficient of the current image; Based on the compensated backlight data of the current image, the backlight brightness of the next frame of the current image is determined.

3. The backlight adjustment method according to claim 2, characterized in that, After the refresh rate of the current image is updated, the backlight data of the current image is compensated, and the compensated backlight data of the current image is used as the backlight data of the next frame of the current image, including: When the refresh rate of the screen changes, save the updated compensation coefficient of the current image and set a flag to update the compensation coefficient. When the backlight of the current image is interrupted, the compensation coefficient of the current image is updated based on the flag; The backlight data corresponding to the current image is determined based on the compensation coefficient of the current image, and the stored backlight data corresponding to the current image is updated. After the processing is completed, the flag is cleared. When the backlight is interrupted in the next frame of the current image, the backlight data corresponding to the current image is sent.

4. The backlight adjustment method according to claim 1, characterized in that, Determining the backlight brightness of the next frame of the current image based on the refresh rate of the current image includes: Get the screen refresh rate; The frequency of the pulse width modulation signal is updated based on the refresh rate of the image. The backlight brightness of the next frame of the current image is determined based on the frequency of the updated pulse width modulation signal.

5. The backlight adjustment method according to claim 4, characterized in that, After the refresh rate of the current image is updated, the backlight data of the current image is compensated, and the compensated backlight data of the current image is used as the backlight data of the next frame of the current image, including: When the refresh rate of the screen changes, the frequency of the pulse width modulation signal of the current image is saved, and a flag for updating the frequency of the pulse width modulation signal is set. When the backlight of the current image is interrupted, the frequency of the pulse width modulation signal of the current image is updated based on the flag; The backlight data corresponding to the current image is determined based on the frequency of the pulse width modulation signal of the current image, and the stored backlight data corresponding to the current image is updated. After the processing is completed, the flag is cleared. When the backlight is interrupted in the next frame of the current image, the backlight data corresponding to the current image is sent.

6. The backlight adjustment method according to claim 1, characterized in that, When rendering the current image, determining the backlight data corresponding to the current image includes: Acquire images of the eye and determine the gaze area of ​​the eye from the images; The gaze area in the current image is defined as the high-definition area, and the remaining area outside the gaze area in the current image is defined as the non-high-definition area. Different layers are used for the high-definition area and the non-high-definition area, and different rendering resolutions are used for the different layers. The backlight data of the rendered layers are calculated separately to obtain two backlight data sets, and the two backlight data sets are combined into one set of backlight data.

7. The backlight adjustment method according to claim 1, characterized in that, The method further includes: Obtain the rotation speed of the display device; The refresh rate of the current image is determined based on the rotation speed and the second correspondence, where the second correspondence is the correspondence between the refresh rate level and the rotation speed range.

8. The backlight adjustment method according to claim 7, characterized in that, The method further includes: The rendering resolution of the current image is determined based on the rotation speed and the third correspondence, wherein the third correspondence is the correspondence between the reduction ratio of the rendering resolution and the rotation speed range.

9. The backlight adjustment method according to claim 8, characterized in that, The rotational speed range in the second correspondence may be the same as or different from the rotational speed range in the third correspondence.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method according to any one of claims 1 to 9.

11. An electronic device, characterized in that, include: processor; as well as Memory for storing the executable instructions of the processor; The processor is configured to execute the method of any one of claims 1 to 9 by executing the executable instructions.

12. The electronic device according to claim 11, characterized in that, The electronic device also includes a display driver chip and a backlight driver chip; The processor includes an image processing module, a display driver module, a data processing module, and a backlight driver module. The image processing module is configured to render the current image, and the data processing module is configured to determine the backlight data corresponding to the current image when rendering the current image. The display driver module is configured to transmit the current image, and the backlight driver module is configured to update the backlight data corresponding to the current image after transmitting the current image for a first preset time. The display driver chip is configured to receive the current image and display the current image on the display screen; The backlight driver chip is configured to receive the backlight data corresponding to the current image, and when the backlight data corresponding to the current image is updated, turn on the backlight source and adjust the backlight brightness based on the backlight data of the current image.

13. The electronic device according to claim 12, characterized in that, The backlight driving module is further configured to determine the backlight brightness of the next frame of the current image based on the refresh rate of the current image.

Images