Front light control method and device of electronic paper device, equipment and storage medium

Abstract

The application relates to the technical field of electronic paper display, and discloses a front light control method and device of an electronic paper device, equipment and a storage medium. In the application, a reflection characteristic value of each monitoring point is first acquired, the reflection characteristic value truly reflects actual reflection light intensity of each control area, and overcomes the defect that a traditional ambient light sensor cannot reflect local brightness difference of a screen; the application determines a reflection estimation value of each control area by using the reflection characteristic values, and generates updated driving parameters in combination with a target reflection index, can dynamically compensate for local shadows or shielding, and improves display uniformity and local readability; and the application also combines a constraint strategy to constrain the driving parameters, the method can ensure stability of front light control, and avoid flickering and oscillation; the application drives the corresponding illumination subunits of the control area by using the constrained driving parameters, can realize precise light compensation of a local area, and avoids power waste caused by globally improving brightness.

Description

Technical Field

[0001] This application relates to the field of electronic paper display technology, and in particular to a front light control method, apparatus, device, and storage medium for an electronic paper device. Background Technology

[0002] An electronic paper terminal refers to a smart electronic device that uses electronic paper as its core display interface. Electronic paper is a reflective display technology that relies on reflecting ambient light to form an image rather than actively emitting light. Therefore, electronic paper terminals are usually equipped with a front light to improve readability in low light.

[0003] Existing front light control methods mainly employ global dimming, which means providing a unified drive signal to all illumination sub-units covering the entire display panel of the e-paper terminal based on ambient light sensors or user manual settings. For example, the solution in CN120898239A mainly discloses that after detecting the ambient illuminance level incident on the viewing surface through an ambient light sensor on the device surface, the ambient illuminance level is compared with a predetermined threshold level to control the front light illuminance incident on the viewing surface from the front light unit. It can be seen that this solution can only achieve global dimming. However, due to factors such as the directionality of ambient light, shadows, and structural inhomogeneity, the reflected brightness of different local areas of the e-paper screen will vary. This will cause some local areas of the screen to have poor readability due to insufficient reflected light, reduce the uniformity of the entire screen display, and, in order to ensure that the darkest areas can be seen clearly, the system has to increase the overall front light brightness, thereby increasing unnecessary power consumption of the e-paper terminal.

[0004] Therefore, how to improve local readability and display uniformity while avoiding unnecessary power consumption is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] This application provides a front light control method, apparatus, device, and storage medium for electronic paper devices to improve local readability and display uniformity while avoiding unnecessary power consumption.

[0006] In a first aspect, this application provides a front light control method for an electronic paper device, comprising: The reflectance characterization value of each monitoring point is obtained; the reflectance characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit; The reflectance values ​​of each monitoring point are used to determine the estimated reflectance values ​​of each control area; Based on the reflection estimates and target reflection indices of each control area, the updated driving parameters of the control area are generated, and the updated driving parameters are constrained using a constraint strategy to obtain the constrained target driving parameters. The illumination subunit corresponding to the target control area is driven to emit light by the target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified.

[0007] Optionally, obtaining the reflectance characterization value for each monitoring point includes: Each monitoring point's control area is controlled to emit light in a first driving state and a second driving state, respectively, to obtain a first sampled value corresponding to the first driving state and a second sampled value corresponding to the second driving state; the brightness of the control area in the first driving state is higher than the brightness of the control area in the second driving state. Based on the first sampled value, the second sampled value, the ambient reference light, and the driving parameters of the control area where the monitoring point is located, an initial characterization value for the monitoring point is generated. The initial characterization value of each monitoring point is processed by time-domain filtering to obtain the reflection characterization value of each monitoring point.

[0008] Optionally, using the reflectance characterization value of each monitoring point, the estimated reflectance value of each control area is determined, including: When determining the reflection estimate of the target control area, identify each target monitoring point that has a mapping relationship with the target control area; Two-dimensional linear interpolation is performed using the reflection characterization values ​​of each target monitoring point and the distance weights of each target monitoring point to obtain the reflection estimate of the target control area; the distance weights of the target monitoring points are inversely proportional to the distances of the target control area from each target monitoring point.

[0009] Optionally, based on the reflection estimates and target reflection indices of each control area, the updated driving parameters for the control areas are generated, including: Calculate the reflection error based on the target reflection index and reflection estimate of each control area; The driving update amount of each control region is calculated using the reflection error, error mapping function, and gain coefficient of each control region. By using the drive update amount, original drive parameters, and upper and lower limits of drive parameters for each control region, the updated drive parameters for the control region are determined.

[0010] Optionally, the updated driving parameters are constrained using a constraint strategy to obtain the constrained target driving parameters, including:

[0011] Apply constraint policies to the updated driving parameters; if the updated driving parameters satisfy each constraint policy, then use the updated driving parameters as the constrained driving parameters; if the updated driving parameters do not satisfy the constraint policies, then use the constraint policies to adjust the driving parameters that do not satisfy the constraint policies to obtain the constrained target driving parameters. The constraint strategy includes at least one of the following: rate of change constraint strategy, hysteresis strategy, smoothing filtering strategy, and power budget constraint strategy.

[0012] Optionally, before obtaining the reflectance characterization value for each monitoring point, the process may also include: The entire display area of ​​the electronic paper device is divided into multiple control areas, and a first mapping relationship is established between each lighting subunit and each control area; a second mapping relationship is established between each monitoring point and each control area. The target reflectance index of each control area is determined using preset factors; the preset factors are at least one of the following: the overall brightness level set by the user, the current ambient light level, the electronic paper device mode, and the statistical characteristics of the display content of the electronic paper device.

[0013] Optionally, after driving the corresponding lighting subunit to emit light, the system further includes: Determine if the triggering condition is met; If so, continue with the step of obtaining the reflection characterization value of each monitoring point; The triggering conditions include: environmental change events, occlusion events, and fixed-period triggering instructions; the environmental change event is: the number of first change monitoring points exceeds a first quantity threshold; the first change monitoring points are monitoring points where the reflectance characterization values ​​change in the same direction and the magnitude of the change exceeds a first magnitude threshold; The occlusion event is defined as follows: the number of second change monitoring points is less than the second quantity threshold, and the control area corresponding to the second change monitoring point is spatially continuous; the second change monitoring point is defined as the decrease in the reflectance value exceeds the second amplitude threshold, and the first quantity threshold is greater than the second quantity threshold.

[0014] Secondly, this application provides a front light control device for an electronic paper device, comprising: The acquisition module is used to acquire the reflection characterization value of each monitoring point; the reflection characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit; The determination module is used to determine the estimated reflection value of each control area using the reflection characterization value of each monitoring point; The parameter generation module is used to generate updated driving parameters for each control area based on the reflection estimate and target reflection index of each control area. The constraint module is used to constrain the updated driving parameters using constraint strategies to obtain the constrained target driving parameters. The driving module is used to drive the illumination sub-unit corresponding to the target control area to emit light through the target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified.

[0015] Thirdly, this application provides an electronic paper device, comprising: Memory, used to store computer programs; A processor is used to implement the steps of the above-described front light control method when executing the computer program.

[0016] Fourthly, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the aforementioned front light control method.

[0017] Compared with the prior art, the above-mentioned technical solution of this application has the following advantages: This application provides a front light control method, device, equipment, and storage medium for electronic paper devices. In this application, the reflection characterization value of each monitoring point is first obtained. This reflection characterization value truly reflects the actual reflected light intensity of each control area, overcoming the defect that traditional ambient light sensors cannot detect local brightness differences on the screen. This application uses each reflection characterization value to determine the reflection estimate value of each control area, and combines it with the target reflection index to generate updated driving parameters, realizing independent and precise supplementary lighting for each control area. It can dynamically compensate for local shadows or occlusions, improving display uniformity and local readability. Furthermore, this application also combines a constraint strategy to constrain the driving parameters. This method can ensure the stability of front light control and avoid flickering and oscillation. This application drives the illumination sub-unit of the corresponding control area through the constrained driving parameters, which can achieve precise supplementary lighting in local areas and avoid the power consumption waste caused by increasing the brightness globally. Therefore, this application can improve the local readability and display uniformity of electronic paper devices while avoiding unnecessary power consumption. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0021] Figure 1 This application provides a schematic flowchart of a front light control method for an electronic paper device. Figure 2 This application provides an overall flowchart of a closed-loop supplemental lighting control method according to an embodiment. Figure 3 A schematic diagram of the front light control device of an electronic paper device provided in this application embodiment; Figure 4 This is a schematic diagram of an electronic paper device provided in an embodiment of this application. Detailed Implementation

[0022] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of this application.

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Furthermore, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0025] In existing technologies, e-paper exhibits inconsistent localized screen reflections under various conditions, including low light, partial screen shadows, partial occlusion, and side-lit hotspots. Traditional global dimming or ambient light-based dimming methods, while simple in structure, cannot dynamically compensate for these differences across the screen, leading to poor readability, unevenness, or increased power consumption in certain areas. It can be seen that existing technologies suffer from at least the following problems: 1) Feedback information is not focused: The ambient light sensor cannot reflect the actual reflection effect of the screen and its spatial distribution; 2) Insufficient control granularity: It is difficult to compensate for local shadows / hot spots globally or in a small number of partitions; 3) Trading power for effect: In order to make the darkest areas readable, the overall brightness is forced to be increased; 4) Lack of configurable closed-loop strategy: There is a lack of transferable control framework for different products / different usage patterns.

[0026] Therefore, to address the aforementioned technical problems, this application provides a front light control method, apparatus, device, and storage medium for electronic paper devices. This application uses the display surface reflection characterization value as a feedback quantity to construct a closed-loop supplementary lighting control scheme involving acquisition, evaluation, generation, and updating. This scheme can provide targeted compensation for local shadows, local occlusion, hotspot areas, and local readability requirements under different usage modes. While improving display uniformity and local readability, it avoids meeting the readability requirements of the darkest areas by globally increasing the front light brightness, thus potentially reducing power consumption. Furthermore, this scheme can serve as a general software / firmware solution for electronic paper front light control, possessing cross-platform reuse capabilities.

[0027] See Figure 1 This is a schematic flowchart of a front light control method for an electronic paper device provided in an embodiment of this application, including: S101. Obtain the reflection characterization value of each monitoring point; the reflection characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit. This application provides a closed-loop supplementary lighting control method for the front light of electronic paper, applicable to electronic paper terminal devices with front light zoning and reflection monitoring capabilities. Before implementing front light control, the control granularity and mapping relationship need to be predetermined. Specifically, this application requires pre-dividing the entire display area of ​​the electronic paper device into a set of control areas, with each control area having a pre-defined mapping relationship with monitoring points and illumination sub-units. Monitoring points refer to sensor sampling locations on the electronic paper screen capable of independently sampling reflection characterization values. These reflection characterization values ​​reflect the reflected light intensity, reflectivity, or brightness state of the corresponding area. Illumination sub-units are independently controllable light-emitting devices in the electronic paper device, used to provide local supplementary lighting for one or more corresponding control areas. By establishing the mapping relationship between control areas, monitoring points, and illumination sub-units, the reflection estimate of each control area can be determined through the monitoring points mapped to the control areas, and supplementary lighting operations can be performed on a portion of the control areas within the entire display area through the illumination sub-units mapped to the control areas.

[0028] When implementing front light control for electronic paper devices, this application requires obtaining the reflection characterization value of each monitoring point. This reflection characterization value can represent the intensity of the light signal reflected at the corresponding monitoring point location under specific front light illumination. This reflection characterization value is positively correlated with the reflected light intensity state. The larger the reflection characterization value, the stronger the reflected light intensity state, that is, the better the electronic paper area's ability to reflect front light, and the higher the display brightness.

[0029] S102. Using the reflection characterization value of each monitoring point, determine the reflection estimate value of each control area; This application obtains the reflection characterization value of each monitoring point, and can then determine the reflection estimate of each control area based on the reflection characterization value of each monitoring point. Specifically, if the second mapping relationship is a one-to-one mapping relationship, the reflection characterization value of the monitoring point can be directly used as the reflection estimate of the corresponding control area; if the second mapping relationship is a one-to-many mapping relationship, that is, one control area corresponds to multiple monitoring points, the reflection characterization values ​​of multiple monitoring points with mapping relationships can be combined into a single reflection estimate by using a weighted average, median, or fusion based on the confidence level of each monitoring point, and this estimate can be used as the reflection estimate of the corresponding control area; if the second mapping relationship is a many-to-one mapping relationship, that is, multiple control areas share the same monitoring point, the reflection estimate of different control areas can be determined based on the distance between different control areas and the monitoring point, with larger distances corresponding to smaller reflection estimates.

[0030] S103. Based on the reflection estimates and target reflection indices of each control area, generate updated driving parameters for the control area, and use constraint strategies to constrain the updated driving parameters to obtain constrained target driving parameters. In this application, it is also necessary to predetermine the target reflectance index for each control area. This target reflectance index refers to the pre-set expected reflectance brightness value for each control area, used to compare with the actually acquired reflectance estimate to generate updated driving parameters. The target brightness distribution of the target reflectance index for all control areas can be a uniform target across the entire screen or different targets for different areas. A uniform target across the entire screen means that the target reflectance index is the same for each control area. Different targets for different areas mean setting different target reflectance indices for different control areas, such as control areas corresponding to the screen edge, control areas corresponding to the screen center, or control areas with different functions. Both methods are acceptable and can be customized according to actual needs.

[0031] After obtaining the reflection estimates and target reflection indices for each control area, this application compares the reflection estimates and target reflection indices for each control area and generates updated driving parameters for the control area based on the comparison results. If the reflection estimate for a certain control area is much lower than the target reflection indices, it indicates that the actual reflection brightness of the control area is far from the expected value, and supplementary lighting needs to be increased. Therefore, the value of the updated driving parameters needs to be increased to drive the illumination subunit to emit stronger light. Conversely, when the reflection estimate for a certain control area is higher than the target reflection indices, it indicates that the control area is too bright and supplementary lighting needs to be reduced. In this case, the value of the driving parameters is reduced to reduce supplementary lighting.

[0032] Furthermore, this application can pre-set a constraint strategy, which is used to apply limiting rules to the updated driving parameters. The constraint strategy can include one or more constraint strategies to perform operations such as checking, correcting, or limiting the updated driving parameters. For example, if the value of the updated driving parameter is too large, it is modified to a predetermined maximum value; if the value of the updated driving parameter is too small, there is no need to modify the driving parameter. For the sake of distinction, this application refers to the driving parameters obtained by constraining the updated driving parameters using the constraint strategy as the target driving parameters. This application can suppress high-brightness flicker and prevent oscillation problems through the constraint strategy to achieve a stable supplementary lighting effect.

[0033] In this application, the driving parameters of the control area can take different numerical forms depending on the hardware implementation method. For example, the driving parameters can be PWM (Pulse Width Modulation) duty cycle, current code, brightness code value, etc.

[0034] S104. Drive the illumination sub-unit corresponding to the target control area to emit light using the target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified.

[0035] After obtaining the constrained target driving parameters, for target control areas where the driving parameters need to be modified, the illumination sub-unit corresponding to the target control area needs to be driven to emit light through the front light driving circuit. When driving the illumination sub-unit corresponding to the target control area to emit light, the brightness of the illumination sub-unit can be changed according to the adjustment of the target driving parameters. That is, the supplementary light can be enhanced to increase the brightness, or the supplementary light can be weakened to reduce the brightness, which is not specifically limited here.

[0036] In summary, this application first obtains the reflection characterization value of each monitoring point, which accurately reflects the actual reflected light intensity of each control area, overcoming the deficiency of traditional ambient light sensors in failing to detect local brightness differences on the screen. This application uses each reflection characterization value to determine the estimated reflection value of each control area and combines it with the target reflection index to generate updated driving parameters, achieving independent and precise supplementary lighting for each control area. This enables dynamic compensation for local shadows or occlusions, improving display uniformity and local readability. Furthermore, this application also incorporates constraint strategies to constrain the driving parameters, ensuring the stability of the front light control and avoiding flickering and oscillations. By driving the illumination sub-units of the corresponding control area with the constrained driving parameters, this application achieves precise supplementary lighting in local areas, avoiding the power consumption waste caused by increasing global brightness. Therefore, this application performs closed-loop control of the electronic paper front light based on screen reflection characterization values, improving display uniformity, contrast, and local readability in complex lighting and occlusion scenarios while reducing overall supplementary lighting power consumption.

[0037] In another embodiment of this application, before obtaining the reflection characterization value of each monitoring point, the method further includes: dividing the entire display area of ​​the electronic paper device into multiple control areas, and establishing a first mapping relationship between each illumination subunit and each control area; and establishing a second mapping relationship between each monitoring point and each control area. The target reflectance index of each control area is determined using preset factors; these preset factors are at least one of the following: the overall brightness level set by the user, the current ambient light level, the electronic paper device mode, and the statistical characteristics of the display content of the electronic paper device.

[0038] Specifically, this application requires pre-dividing the entire display area of ​​the electronic paper device into multiple control areas. The control areas can be divided using a partitioned matrix, for example, dividing the entire display area into an M-row, N-column rectangular grid, with each grid cell representing a control area. Alternatively, a finer-grained partitioning method can be used, such as irregular shapes or higher-density control partitions, to meet the needs of different hardware structures and control precision requirements. Furthermore, after dividing the control areas, this application also needs to establish a first mapping relationship between each illumination subunit and each control area. This first mapping relationship determines which control areas each illumination subunit is responsible for illuminating.

[0039] The first mapping relationship can take various forms, such as one-to-one, one-to-many, and many-to-one. A one-to-one mapping relationship means that one lighting sub-unit corresponds to one control area; a one-to-many mapping relationship means that one lighting sub-unit corresponds to multiple control areas simultaneously; and a many-to-one mapping relationship means that multiple lighting sub-units share the same control area. The specific first mapping relationship can be selected and used in any combination based on the actual hardware structure and control requirements.

[0040] Furthermore, since the reflective brightness may vary in different areas of the electronic paper screen, this application sets a set of monitoring points at multiple predetermined locations in the electronic paper device. The set of monitoring points includes several monitoring points, and a second mapping relationship is established between each monitoring point and a control area. Similarly, the second mapping relationship can be at least one of a one-to-one mapping relationship, a one-to-many mapping relationship, and a many-to-one mapping relationship. That is, one or more corresponding monitoring points can be set for each control area, or sparse monitoring points can be used to cover multiple control areas; this is not specifically limited here.

[0041] When determining the target reflectance index of each control area, this application can specifically determine the target reflectance index of each control area based on preset factors. These preset factors are determined by a combination of one or more of the following: the overall brightness level set by the user, the current ambient light level, the electronic paper device mode, and the statistical characteristics of the display content of the electronic paper device. Here, the relationship between each preset factor and the target reflectance index is explained: 1) The overall brightness level set by the user applies to the entire screen. The higher the overall brightness level, the higher the value of the target reflection index in each controlled area.

[0042] 2) The current ambient light level is determined by the values ​​collected by the ambient light sensor of the electronic paper device. The higher the current ambient light level, the higher the value of the target reflectance index in each control area.

[0043] 3) Electronic paper device modes include reading mode, handwriting mode, and signage mode. In reading mode, to ensure comfortable viewing over extended periods, the target reflectivity of each control area tends to be more uniform. Therefore, in reading mode, the target reflectivity of each control area is set to the same predetermined value. In handwriting mode, higher legibility of the handwriting area is desired. Therefore, the target reflectivity of the control area corresponding to the handwriting area can be set higher than that of the control area corresponding to the non-handwriting area. In signage mode, it is necessary to clearly see advertising signs on a flat surface in public places. Therefore, in signage mode, the target reflectivity of each control area needs to be set to a higher predetermined value, which can be adjusted as needed.

[0044] 4) Display content statistical features are obtained by analyzing the current display content on the terminal. Feature types include, but are not limited to: text / line density, black and white pixel ratio, local contrast, edge density, blank area ratio, and key display area position. The display content statistical features can be determined as follows: the controller reads the current display frame buffer content and extracts statistical features through image analysis algorithms. When extracting statistical features, it is not necessary to analyze pixel by pixel. Statistics can be performed in blocks (such as 16×16 pixel blocks) to reduce the amount of calculation. The calculation only needs to be performed once when the display content is updated (electronic paper has a low refresh rate and minimal computational overhead).

[0045] Different feature types have different effects on target reflectance metrics. For example: text / line density reflects the proportion of black pixels in the area; the higher the density, the higher the target reflectance metric of the corresponding control area, thus enhancing recognizability; black and white pixel ratio is the ratio of black pixels (containing content) to white pixels (blank); the higher the proportion of black, the higher the target reflectance metric of the corresponding control area; local contrast is the grayscale variance of pixels in the area; the lower the contrast (e.g., light gray thin text), the higher the target reflectance metric of the corresponding control area, to compensate for visibility; edge density is the edge detection response intensity in the area; the denser the edges (fine graphics / small text), the higher the target reflectance metric of the corresponding control area; blank area ratio is the proportion of areas without content; the higher the blank area ratio, the lower the target reflectance metric of the corresponding control area, reducing ineffective fill light; the key display area identifier is the attention area specified by the system / application layer (e.g., pop-ups, near the cursor, highlighted areas), and the target reflectance metric of the control area corresponding to the key display area is additionally increased.

[0046] In other words, the more complex and important the displayed content, the higher the corresponding target reflectance index value, and the more aggressive the supplementary lighting; the simpler and blanker the content, the lower the corresponding target reflectance index value, focusing on power saving. For example, when the content consists of high-density text, fine lines, or many low-contrast areas, the target reflectance index value of the corresponding control area can be increased to enhance visibility; when some control areas are blank areas, background areas, or non-key display areas, the target reflectance index value can be decreased to reduce ineffective supplementary lighting; when the system identifies a key display area or an area of ​​user interest, the target reflectance index value of the control area corresponding to that key display area or area of ​​user interest can also be additionally increased.

[0047] It should be noted that if the target reflectance index is determined by at least two preset factors, a weighted fusion method can be used to first determine the basic target value, and then combine it with the regional correction coefficient to obtain the final target reflectance index. That is: the initial reflectance index obtained from each preset factor and the weight coefficient of each preset factor are used to calculate the basic target value, and the corresponding regional correction coefficient is determined according to the different importance of different control areas. The basic target value and the corresponding regional correction coefficient of each control area are then weighted and fused to obtain the final target reflectance index of each control area.

[0048] In summary, this application pre-divides the display area into multiple control zones and establishes mapping relationships between lighting sub-units and control zones, as well as between monitoring points and control zones. This allows for compatibility with different partitioning granularities and cross-platform reuse capabilities. Furthermore, it utilizes at least one of the following factors—the user-defined overall brightness level, the current ambient light level, the electronic paper device mode, and statistical characteristics of the displayed content—to determine the target reflectivity of each control zone. This enables the supplementary lighting operation to be dynamically adjusted according to the usage scenario and screen content, further improving readability and energy efficiency.

[0049] In another embodiment of this application, obtaining the reflectance characterization value of each monitoring point includes: Each monitoring point's control area is controlled to emit light in a first driving state and a second driving state, respectively, to obtain a first sampled value corresponding to the first driving state and a second sampled value corresponding to the second driving state; the brightness of the control area in the first driving state is higher than the brightness of the control area in the second driving state. Based on the first sampled value, the second sampled value, the ambient reference light, and the driving parameters of the control area where the monitoring point is located, the initial characterization value of the monitoring point is generated; the initial characterization value of each monitoring point is subjected to time-domain filtering to obtain the reflection characterization value of each monitoring point.

[0050] In determining the reflection characterization value of each monitoring point, this application first needs to obtain the initial characterization value of each monitoring point and then filter it to obtain the final reflection characterization value of each monitoring point. The initial characterization value of each monitoring point is obtained as follows: Two sampling operations are performed on the monitoring point. The first sampling is performed in the first driving state, where the corresponding control area emits light at a higher brightness or in the target working driving state. The obtained first sampled value includes ambient light, direct front light / crosstalk, and screen reflection contributions. The second sampling is performed in the second driving state, where the corresponding control area operates at a lower brightness, in the reference driving state, or in the off state. The obtained second sampled value mainly includes ambient light and background components. When calculating the initial characterization value, the first sampled value in the first driving state can be denoted as S1, and the second sampled value in the second driving state can be denoted as S2. Then, the difference Δ between the first and second sampled values ​​of each monitoring point is calculated: Δ = S1 - S2. This difference value is used to characterize the net contribution related to front light, thereby eliminating common-mode interference such as ambient light, sensor dark current, and background components to a certain extent. Then, by combining the ambient reference light and the driving parameters of the control area, the initial characterization value of the monitoring point is obtained.

[0051] The specific calculation formula can be: ;in, This is the initial reflection characterization value (initial characterization value). Let Δ be the mapping function, and Δ be the difference value. For compensation coefficient, For environmental reference values, These are the driving parameters for the control area. In other words, the initial characterization value can be understood as: a value obtained by normalizing or mapping the difference value, combined with the ambient reference light for compensation, and then combined with the front light partition driving parameters.

[0052] After obtaining the initial characterization values ​​of each monitoring point, this application needs to perform time-domain filtering on the initial characterization values ​​of each monitoring point to suppress noise and obtain the reflection characterization value of each monitoring point. Specifically, the initial characterization value in this application is the initial reflection characterization value obtained by the monitoring point in the current sampling period. Since the reflection characterization value itself comes from at least two samplings of the same monitoring point in the first driving state and the second driving state, and is calculated in combination with the ambient reference light and the front light partition driving parameters, this application can further reduce the impact of sensor random noise, environmental disturbances and instantaneous fluctuations on closed-loop control by performing time-domain filtering on each monitoring point after obtaining the initial reflection characterization value of each monitoring point. Time-domain filtering includes: moving average filtering, IIR (Infinite Impulse Response) filtering, etc. Moving average filtering refers to taking the average of multiple initial reflection characterization values ​​continuously collected for each monitoring point as the final reflection characterization value of the monitoring point; IIR filtering refers to using the current new initial reflection characterization value and the historical reflection characterization value for weighted summation to obtain the final reflection characterization value of the monitoring point.

[0053] In summary, this application obtains first and second sampled values ​​by controlling the control area where each monitoring point is located to emit light in a first driving state (high brightness) and a second driving state (low brightness), respectively. It uses differential operation to eliminate common-mode interference such as ambient light and sensor dark current. Then, it combines ambient reference light for compensation and introduces time-domain filtering to suppress random noise and instantaneous fluctuations, thereby obtaining more accurate and stable reflection characterization values. This effectively avoids front light flicker or misadjustment caused by sampling errors, thereby improving the overall control accuracy.

[0054] In another embodiment of this application, determining the estimated reflectance value of each control area using the reflectance characterization value of each monitoring point includes: When determining the reflection estimate of the target control area, identify each target monitoring point that has a mapping relationship with the target control area; Two-dimensional linear interpolation is performed using the reflection characterization values ​​of each target monitoring point and the distance weights of each target monitoring point to obtain the reflection estimate of the target control area; the distance weights of the target monitoring points are inversely proportional to the distances of the target control area from each target monitoring point.

[0055] In this application, sparse monitoring points can be used to cover multiple control areas. Specifically, monitoring points can be set up in every N×N area, and the reflection estimates for the remaining areas are estimated through interpolation / area aggregation. Setting up monitoring points in an N×N area means placing one physical monitoring point every N rows and N columns on a regular grid. For example, if the screen is divided into 16×16=256 control areas and N=4, then one monitoring point is set up every 4 rows and 4 columns. The monitoring point locations are: (1,1),(1,5),(1,9),(1,13),(5,1),(5,5),(5,9),(5,13),...(13,13), totaling (16 / 4)×(16 / 4)=16 monitoring points, using 16 sensors to cover 256 areas.

[0056] To clearly describe this scheme, each control area requiring a reflection estimate is referred to as the target control area. This application uses bilinear interpolation to calculate the reflection estimate of the target control area, specifically including: determining each target monitoring point that has a mapping relationship with the target control area, and obtaining the reflection characterization value of each target monitoring point; for example, if the target control area is located between four monitoring points, a mapping relationship is pre-established between the target control area and these four monitoring points. When calculating the target control area, the four target monitoring points with the mapping relationship can be determined based on this mapping relationship, and the reflection characterization values ​​of these four target monitoring points can be obtained. After obtaining the reflection characterization values ​​of each target monitoring point, two-dimensional linear interpolation is performed using the reflection characterization values ​​of each target monitoring point and the distance weights of each target monitoring point to obtain the reflection estimate of the target control area. The distance weights of the target monitoring points are inversely proportional to the distances from the target control area to each target monitoring point.

[0057] For example, if the target control area k is located between four target monitoring points, then the formula for two-dimensional linear interpolation with distance as the weight is: ; in, The reflection estimate for the target control area k. The estimated reflection value for the first target monitoring point. The distance weight for the first target monitoring point. The estimated reflection value for the second target monitoring point. The distance weight for the second target monitoring point, The reflection estimate for the third target monitoring point. The distance weight for the third target monitoring point, The estimated reflection value for the fourth target monitoring point. The distance weight of the fourth target monitoring point is inversely proportional to the distance from the target monitoring point to the target control area k. That is, the closer the distance, the greater the weight, ∑w=1.

[0058] In addition to using the bilinear interpolation method described above to determine the reflection estimate of the target control area, this application can also use the nearest neighbor assignment method and the region aggregation method. When using the nearest neighbor assignment method, each control area uses the reflection estimate of the nearest monitoring point as the reflection estimate, which is simple to implement. The region aggregation method refers to dividing the screen into several large blocks, each block containing a monitoring point, and all control areas within the block share the value of the monitoring point. This method is suitable for scenarios with low cost and low precision requirements.

[0059] In summary, this scheme, in scenarios with sparsely distributed monitoring points, determines each target monitoring point that has a mapping relationship with the target control area, and uses the reflection characterization value of each monitoring point and its distance weight to perform two-dimensional linear interpolation, thereby smoothly and accurately estimating the reflection value of each control area. This method reduces the number of physical monitoring points to lower hardware costs, avoids brightness discontinuities between areas, and ensures the continuity and uniformity of supplementary lighting control.

[0060] In another embodiment of this application, generating updated driving parameters for the control regions based on the reflection estimates of each control region and the target reflection index includes: Calculate the reflection error based on the target reflection index and reflection estimate of each control area; The driving update amount of each control region is calculated using the reflection error, error mapping function, and gain coefficient of each control region. By using the drive update amount, original drive parameters, and upper and lower limits of drive parameters for each control region, the updated drive parameters for the control region are determined.

[0061] In this application, the updated driving parameters are obtained by calculating the regional error and generating the supplementary lighting drive update amount. This application addresses each control region. And generate regional reflectance estimates based on the reflectance characterization values ​​of its associated monitoring points. Then, the reflection error needs to be calculated based on the target reflection index and reflection estimate of each control area. , that is: ,in, For control area The target reflection index is then determined. Based on the reflection error, error mapping function, and gain coefficient, the drive update amount for each control region is calculated. The formula for calculating the drive update amount is: ; in, For control area Driver update volume This is the gain coefficient, used to control the sensitivity of the control area to error response. The gain coefficient can be uniform across the entire area, such as 0.5 for each control area; or it can be configured in zones, such as a higher gain coefficient for the control area in the center of the screen and a lower gain coefficient for the control area at the edge of the screen. The error mapping function maps the original reflection error to a driving update value. When the reflection error is greater than zero, it indicates that the estimated reflection value is lower than the target reflection index, and supplementary lighting needs to be increased; when the reflection error is less than zero, it indicates that the estimated reflection value exceeds the target reflection index, and supplementary lighting needs to be reduced. In this application, the error mapping function is a monotonic function, including linear functions, piecewise functions, functions with dead zones, etc. If f is a linear function: If f is a piecewise function, different slopes can be used in different error intervals; a gentle slope for small errors and a steep slope for large errors. If f is a function with a dead zone: when hour, =0 (no response to small errors); otherwise ; This is the dead zone threshold, which can be customized according to the actual situation and is not specifically limited here. It is a symbolic function.

[0062] The above process generates a driving update quantity based on the reflection error. Then, based on the driver update amount, the original driver parameters, and the upper and lower limits of the driver parameters, the updated driver parameters need to be obtained. In this application, the updated formula for the driver parameters is: ; in: The updated driving parameters for control region k. The original driving parameters before the control region k is updated are defined by `clip`, which is a limiting function used to limit the calculation results within a safe range, avoiding excessive brightness or power consumption. This is the lower limit of the driving parameters, used to prevent the screen from becoming completely unreadable due to low brightness. The upper limit of the driving parameters is set to prevent excessive brightness from causing eye strain or exceeding power consumption. The lower and upper limits of the driving parameters can be customized according to actual conditions and are not specifically limited here. The process of determining the updated driving parameters in this way is as follows: after increasing the original driving parameters by the driving update amount, the amplitude is limited (within the upper limit of the driving parameters) to obtain the updated driving parameters.

[0063] In summary, this scheme first calculates the reflection error based on the reflection estimate of each control area and the target reflection index, quantifying the current brightness deviation; then, it uses the error mapping function and gain coefficient to calculate the drive update amount, realizing a controllable mapping from error to drive adjustment amount; finally, it combines the original drive parameters and the upper and lower limits of the drive parameters to determine the updated drive parameters, and uses a limiting operation to prevent excessive brightness, excessive darkness, or exceeding the allowable power consumption range.

[0064] In another embodiment of this application, the updated driving parameters are constrained using a constraint strategy to obtain the constrained target driving parameters, including:

[0065] Apply constraint policies to the updated driving parameters; if the updated driving parameters satisfy each constraint policy, then use the updated driving parameters as the constrained driving parameters; if the updated driving parameters do not satisfy the constraint policies, then use the constraint policies to adjust the driving parameters that do not satisfy the constraint policies to obtain the constrained target driving parameters. The constraint strategy includes at least one of the following: rate of change constraint strategy, hysteresis strategy, smoothing filtering strategy, and power budget constraint strategy.

[0066] In this application, after obtaining the updated driving parameters, it is also necessary to apply constraints and stabilization strategies to the updated driving parameters to prevent flicker / oscillation. Specifically, the constraint strategies applied in this application include at least one of the following: rate of change limiting strategy, hysteresis strategy, smoothing filtering strategy, and power budget constraint strategy.

[0067] The rate of change constraint strategy is as follows: ; The updated drive parameters for the current control cycle. The final target driving parameters of the previous control cycle, The rate of change threshold can be customized according to the actual application and is not specifically limited here. That is, the rate of change between the updated driving parameters of the current control cycle and the final target driving parameters of the previous control cycle is calculated. If the rate of change is greater than the rate of change threshold, the rate of change limiting strategy is not met, and the updated driving parameters of the current control cycle need to be adjusted so that the adjusted driving parameters are not greater than the rate of change threshold. In this way, the maximum change of driving parameters between adjacent cycles can be limited, preventing sudden changes in brightness caused by instantaneous noise of the sensor or sudden changes in the environment, and achieving anti-flicker.

[0068] Hysteresis strategy refers to: when The time frame remains unchanged; that is, if the absolute value of the reflection error in the current control cycle is less than the dead zone threshold, there is no need to adjust the driving parameters of the control region. The original driving parameters from the previous control cycle can be maintained, thus avoiding repeated jitter caused by small errors. The smoothing filtering strategy refers to low-pass filtering or exponential smoothing of the updated driving parameters. This smooths the driving parameters of each control region in the time dimension, preventing drastic jumps in driving values ​​between adjacent cycles.

[0069] The power budget constraint strategy is as follows: Where P is the power function, which updates the driving parameters. This is mapped to the actual power consumption of that region. Typical form: If For PWM duty cycle: (Linear mapping); Rated forward current, This is the operating voltage of the lighting subunit; if If it is a constant current code value, it is mapped to the actual power consumption through a lookup table or fitting function; A preset total power consumption budget limit is set for the system, such as the total front light power consumption not exceeding 1W. If the sum of the actual power consumption of all control areas (total power consumption) exceeds the total power consumption budget limit, scaling is performed according to priority. Here, priority is a preset weight for each control area, reflecting the importance of that area to the user experience. When the total power consumption exceeds the budget, the drive parameters are reduced step by step, starting from the area with the lowest priority.

[0070] For example: If the control area is an edge / blank / non-focused area, the priority preset weight p=0. The driving parameters of this control area are reduced first, with the smallest scaling factor. For example, the adjusted driving parameters are multiplied by 0.5~0.7. If the control area is a normal display area, the priority preset weight p=1. After the above adjustments, if the total power consumption still exceeds the total power consumption budget limit, a moderate reduction is performed. The scaling factor of p=1 is greater than the scaling factor of p=0. If the control area is a core reading area, the priority preset weight p=2. If the total power consumption still exceeds the total power consumption budget limit after the above adjustments, further reduction is performed. At this time, the reduction is smaller, and the scaling factor of p=2 is greater than the scaling factor of p=1. If the control area is a user-focused / interactive hotspot area, the priority preset weight p=3. If the above conditions are still not met, a final reduction or no reduction can be performed. The scaling factor is the largest, such as multiplying the updated driving parameters by 0.9~1.0. That is, the higher the priority, the less the driving parameters are scaled, and the better the fill light effect is preserved.

[0071] In summary, this solution applies at least one constraint strategy to the updated driving parameters, including rate of change limiting, hysteresis, smoothing filtering, and power budget constraints. When the constraints are met, the output is directly provided; otherwise, adjustments are made proactively. Specifically, rate of change limiting prevents flickering caused by drastic brightness jumps between adjacent cycles; hysteresis avoids repeated jitter caused by minor errors; smoothing filtering prevents drastic jumps in driving values ​​between adjacent cycles; and power budget constraints ensure that the total power does not exceed the system limit, and when the limit is exceeded, it is scaled according to priority, prioritizing illumination of the core area.

[0072] In another embodiment of this application, after driving the corresponding lighting subunit to emit light, the method further includes: Determine if the triggering condition is met; If so, continue with the step of obtaining the reflection characterization value of each monitoring point; The triggering conditions include: environmental change events, occlusion events, and fixed-period triggering instructions; the environmental change event is: the number of first change monitoring points exceeds a first quantity threshold; the first change monitoring points are monitoring points where the reflectance characterization values ​​change in the same direction and the magnitude of the change exceeds a first magnitude threshold; The occlusion event is defined as follows: the number of second change monitoring points is less than the second quantity threshold, and the control area corresponding to the second change monitoring point is spatially continuous; the second change monitoring point is defined as the decrease in the reflectance value exceeds the second amplitude threshold, and the first quantity threshold is greater than the second quantity threshold.

[0073] In this application, after determining the target driving parameters of the control area through the above process, the target driving parameters are output to the front light driving circuit to drive the corresponding illumination subunit to provide supplemental lighting to the corresponding control area. Furthermore, this application can automatically trigger the update of the driving parameters when triggering conditions are met. These triggering conditions include: fixed-cycle trigger commands, environmental change events, and occlusion events. Fixed-cycle trigger commands mean that a fixed-cycle trigger command needs to be generated in each control cycle to trigger the system to continue acquiring the reflection characterization value of each monitoring point and updating the driving parameters of the control area. Additionally, if this application detects environmental change events or occlusion events, it indicates that the current environment has changed or occlusion exists, and an update is also triggered at this time.

[0074] Specifically, this application does not rely on a separate ambient light sensor. Instead, it determines whether an environmental change event or an occlusion event has occurred by measuring the change in the reflectance value of the monitoring point itself. Since the reflectance value is the light directly collected after reflection from the screen, rather than the indirect ambient illuminance, the reduced reflection caused by occlusion is directly reflected as a decrease in the reflectance value. Therefore, using the monitoring point to obtain the reflectance value is more sensitive and accurate than using an ambient light sensor on the device housing. Thus, this application can use the same sensor array to simultaneously complete feedback sampling and change detection.

[0075] Among them, this application determines whether to generate an environmental change event by detecting whether the ambient light changes violently, that is: if the number of first change monitoring points exceeds the first quantity threshold, and the first change monitoring points are monitoring points where the reflection characterization values change in the same direction and the change amplitude exceeds the first amplitude threshold, it is determined that an environmental change event occurs. The first quantity threshold can be custom-set according to the actual situation. In this embodiment, the first quantity threshold can be set to N_total / 2, where N_total is the total number of monitoring points, that is: within a short period of time (such as within 2 to 3 sampling periods), the reflection characterization values of most monitoring points change significantly in the same direction, such as rising or falling simultaneously, and the change amplitude exceeds the first amplitude threshold R_threshold_ambient. At this time, an environmental change event is generated. The occurrence of this event represents that the user turns on or off the light, walks into the shadow, the frequency flash caused by the passing of a train, etc. In these cases, almost all monitoring points will jump in the same direction.

[0076] This application can determine to generate an occlusion event when detecting local occlusion, that is: if the number of second change monitoring points is less than the second quantity threshold, and the control area corresponding to the second change monitoring points is spatially continuous, and the second change monitoring points are monitoring points where the reflection characterization value drops by more than the second amplitude threshold, it is determined that an occlusion event occurs. The second quantity threshold can be custom-set according to the actual situation. The first quantity threshold is greater than the second quantity threshold. In this embodiment, the second quantity threshold is set to N_total / 4, that is: if the reflection characterization values of the monitoring points in a specific continuous area suddenly drop significantly, but the monitoring points at a relatively far distance change little, when the drop amplitude exceeds the second amplitude threshold R_threshold_occlusion and only a few adjacent monitoring points are involved, it is determined as local occlusion. For example, a hand covers a corner of the screen or a book presses on the screen.

[0077] That is to say: if the number of change monitoring points > N_total / 2 and the change directions are the same, an environmental change event is generated; if the number of change monitoring points < N_total / 4 and it is spatially continuous, an occlusion event is generated; after the above two events are triggered, parameter update is immediately executed without waiting for a fixed period.

[0078] In summary, after driving the lighting sub-unit to supplement light, this solution continuously determines whether the trigger conditions are met, including environmental change events, occlusion events, and fixed-period triggers. If the above environmental change events and occlusion events are detected, a complete closed-loop update is immediately triggered without waiting for a fixed period. This mechanism enables the system to quickly respond to environmental mutations and local occlusions, timely adjust the light supplement degree of different areas, and improve the dynamic performance of control.

[0079] It should be noted that when obtaining the target driving parameters in this application, it is not only necessary to determine them based on the reflection estimates of each control area and the target reflection index, but also to introduce priority supplementary lighting, that is, to assign higher weight to the user-focused area. This user-focused area includes the control area where the stylus is located in real time, the control area where the eye-tracking gaze point is located, and the control area where the touch interaction coordinates are located. After assigning higher weight to the user-focused area, in subsequent error calculation and driving parameter update steps, the control area with higher weight can amplify its error; or, increase the upper limit of the driving parameters for that control area; or, ensure that the driving parameters for that area are not reduced within the power consumption budget constraint. In this way, the system can dynamically tilt the supplementary lighting resources towards the local area currently focused on by the user, ensuring that the displayed content at the handwriting, gaze point, or touch interaction point has higher recognizability and readability, thereby significantly improving the interactive experience.

[0080] Furthermore, the gain coefficient used in calculating the driver update amount in this application can be adaptively adjusted according to the noise level and the rate of environmental change, thereby improving stability and response speed. Specifically, the gain coefficient controls the sensitivity of the corresponding region to error response. A large gain coefficient results in a fast response but is prone to oscillation; a small gain coefficient results in stability but a slow response. Adaptive adjustment allows the system to increase the gain coefficient when a fast response is needed and decrease the gain coefficient when noise is high / the environment is stable.

[0081] When adjusting based on noise levels, the first step is to measure the noise level. This involves calculating the standard deviation of the reflection characteristics (or differential values) over the most recent N periods. If the standard deviation exceeds a predetermined threshold, it indicates high noise, and the gain coefficient is reduced to prevent noise from being amplified into brightness jitter. If the standard deviation does not exceed the predetermined threshold, it indicates signal stability, and the default gain coefficient is restored. The gain coefficient adjustment strategy is as follows: ; in, This is the automatically adjusted gain coefficient. This is the default gain factor. The specific value of the default gain factor can be customized according to the actual situation. denoted as σ, where σ is the standard deviation of the reflection characterization value, and β is the noise sensitivity coefficient.

[0082] When adjusting the gain coefficient based on the rate of environmental change, this application specifically measures the rate of change of the regional reflection estimate over the most recent control periods, and calculates accordingly. , The change in the estimated reflectance value of the control region k is the amount of change. This is the reflection estimate for the nth control cycle. This is the reflection estimate for the (n-1)th control cycle. If the reflection estimate changes rapidly and significantly, such as when a user suddenly blocks the light with their hand, turns on a light, or walks into sunlight, the gain coefficient is increased to accelerate convergence. If the reflection estimate changes slowly and significantly, it indicates a stable scenario such as static reading, so the gain coefficient is decreased to reduce unnecessary fine-tuning.

[0083] The specific adjustment strategy is as follows: when ,but ;in, The threshold for high-speed change. This is the automatically adjusted gain coefficient. This is the default gain coefficient. As an acceleration factor, K_boost = 1.5~2.0, which accelerates convergence; when And when it lasts for M cycles, ; The threshold values ​​for low-speed changes and high-speed changes can be customized according to actual conditions. The steady-state coefficient, K_calm = 0.5~0.7, indicates the state has reached steady state. Other cases... .

[0084] In this application, a synthesis strategy can also be used to determine the gain coefficient: ; in, For noise factor, The environmental variation factor is attenuated when noise is high, with A_noise ≤ 1; A_speed is dynamically adjusted between 0.5 and 2.0 according to the changes. Alternatively, the smaller of the noise factor and the environmental variation factor can be used to determine the gain coefficient, ensuring that the gain is not excessively amplified due to rapid changes in noisy environments.

[0085] See Figure 2 The following is an overall flowchart of a closed-loop supplemental lighting control method provided in an embodiment of this application. The process includes the following: S201, Determine the set of control areas and their mapping relationships; the mapping relationship is the mapping relationship between the lighting sub-units and monitoring points of each control area.

[0086] S202, obtain the reflection characterization values ​​of each monitoring point.

[0087] S203, generate target reflection indices for each control area.

[0088] S204, calculate the reflection estimate for each control area, calculate the error between the reflection estimate and the target reflection index, generate the driving update amount based on the error, and update the driving parameters.

[0089] S205 applies stabilization and constraint processing to the updated drive parameters.

[0090] S206 outputs the processed driving parameters to the front light driving circuit to drive the corresponding lighting sub-unit to emit light.

[0091] S207, determine whether an update has been triggered, such as by detecting an environmental change event, an occlusion event, or the arrival of a fixed period; if triggered, return to S202 and reacquire the reflection characterization value for closed-loop iteration; otherwise, continue to wait for the next trigger.

[0092] As can be seen from the above, this invention uses the local reflection characterization value of the screen as the closed-loop feedback quantity to directly calculate and update the driving parameters of each illumination sub-unit, so that the screen reflection brightness distribution gradually approaches the preset target distribution. This reduces unnecessary supplementary lighting and lowers overall power consumption while ensuring local readability. At the same time, this method supports a general framework for sparse monitoring points, region estimation, and driving updates, is compatible with different partition granularities, and has good configurability and scalability. In addition, by introducing stabilization strategies such as rate of change limitation, dead zone / hysteresis, smoothing filtering, and power budget constraints, flicker and control oscillation are effectively suppressed, ensuring the engineering implementation of closed-loop control. The target distribution can be flexibly generated by combining user brightness level, ambient light level, device mode, and statistical characteristics of display content, so that the control method can be transferred to different products and usage scenarios.

[0093] In other words, this application has at least the following beneficial effects: Improved local readability: It can dynamically supplement light for uneven local shadows or hot spots, so that the reflective brightness of key areas reaches the target; Improved uniformity: Closed-loop control makes the reflective characterization values ​​of each area tend to be consistent or tend to the preset target distribution; Potential for reduced power consumption: It only increases the drive for the area that needs compensation, avoiding excessive supplementary light for the whole screen; Strong adaptability: It can respond to changes in occlusion and lighting, and adapt to different product structures and partition configurations; Engineering feasibility: Through strategies such as amplitude limiting / dead zone / rate of change limitation, it reduces flicker and oscillation, and improves the stability of the experience.

[0094] The front light control device provided in the embodiments of this application is described below. The front light control device described below can be referred to in correspondence with the method described above.

[0095] See Figure 3 , Figure 3 This application provides a schematic diagram of the front light control device for an electronic paper device, which specifically includes: The acquisition module 11 is used to acquire the reflection characterization value of each monitoring point; the reflection characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit; Module 12 is used to determine the estimated reflection value of each control area using the reflection characterization value of each monitoring point; The parameter generation module 13 is used to generate updated driving parameters for each control area based on the reflection estimate and target reflection index of each control area. Constraint module 14 is used to constrain the updated driving parameters using a constraint strategy to obtain the constrained target driving parameters; The driving module 15 is used to drive the illumination sub-unit corresponding to the target control area to emit light through the target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified.

[0096] As an optional embodiment, the acquisition module is specifically used for: Each monitoring point's control area is controlled to emit light in a first driving state and a second driving state, respectively, to obtain a first sampled value corresponding to the first driving state and a second sampled value corresponding to the second driving state; the brightness of the control area in the first driving state is higher than the brightness of the control area in the second driving state. Based on the first sampled value, the second sampled value, the ambient reference light, and the driving parameters of the control area where the monitoring point is located, an initial characterization value for the monitoring point is generated. The initial characterization value of each monitoring point is processed by time-domain filtering to obtain the reflection characterization value of each monitoring point.

[0097] As an optional embodiment, the determining module is specifically used for: When determining the reflection estimate of the target control area, identify each target monitoring point that has a mapping relationship with the target control area; Two-dimensional linear interpolation is performed using the reflection characterization values ​​of each target monitoring point and the distance weights of each target monitoring point to obtain the reflection estimate of the target control area; the distance weights of the target monitoring points are inversely proportional to the distances of the target control area from each target monitoring point.

[0098] As an optional embodiment, the parameter generation module is specifically used for: Calculate the reflection error based on the target reflection index and reflection estimate of each control area; The driving update amount of each control region is calculated using the reflection error, error mapping function, and gain coefficient of each control region. By using the drive update amount, original drive parameters, and upper and lower limits of drive parameters for each control region, the updated drive parameters for the control region are determined.

[0099] As an optional embodiment, the constraint module is specifically used for:

[0100] Apply constraint policies to the updated driving parameters; if the updated driving parameters satisfy each constraint policy, then use the updated driving parameters as the constrained driving parameters; if the updated driving parameters do not satisfy the constraint policies, then use the constraint policies to adjust the driving parameters that do not satisfy the constraint policies to obtain the constrained target driving parameters. The constraint strategy includes at least one of the following: rate of change constraint strategy, hysteresis strategy, smoothing filtering strategy, and power budget constraint strategy.

[0101] As an optional embodiment, the device further includes: The partitioning module is used to divide the entire display area of ​​the electronic paper device into multiple control areas; A module is established to create the first mapping relationship between each lighting sub-unit and each control area; and to establish the second mapping relationship between each monitoring point and each control area. The setting module is used to determine the target reflection index of each control area using preset factors; the preset factors are at least one of the following: the overall brightness level set by the user, the current ambient light level, the electronic paper device mode, and the statistical characteristics of the display content of the electronic paper device.

[0102] As an optional embodiment, the device further includes: The judgment module is used to determine whether the triggering conditions are met; if so, the acquisition module is triggered again. The triggering conditions include: environmental change events, occlusion events, and fixed-period triggering instructions. The environmental change event is: the number of first change monitoring points exceeds a first quantity threshold. The first change monitoring points are monitoring points where the reflectance characterization values ​​change in the same direction and the change amplitude exceeds a first amplitude threshold. The occlusion event is defined as follows: the number of second change monitoring points is less than the second quantity threshold, and the control area corresponding to the second change monitoring point is spatially continuous; the second change monitoring point is defined as the decrease in the reflectance value exceeds the second amplitude threshold, and the first quantity threshold is greater than the second quantity threshold.

[0103] Figure 4 A structural diagram of an electronic paper device provided in an embodiment of the present invention includes: Memory 20 is used to store computer programs; The processor 21 is configured to execute a computer program to implement the steps of the method described in any of the above embodiments.

[0104] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one hardware form selected from Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), and Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which handles computational operations related to machine learning.

[0105] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of the method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary storage or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc.

[0106] In some embodiments, the electronic paper device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0107] Those skilled in the art will understand that Figure 4 The structure shown does not constitute a limitation on electronic paper devices and may include more or fewer components than illustrated.

[0108] In another exemplary embodiment, a computer storage medium is also provided, wherein the program instructions, when executed by a processor, implement the steps of the method described in any of the above method embodiments.

[0109] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the current technology, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods in the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, magnetic disks, or optical disks, and other media capable of storing program code.

[0110] The various embodiments described in this specification are presented in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” used herein may also mean the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a specific order described or illustrated, unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0111] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0112] The above are only some embodiments of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for controlling the front light of an electronic paper device, characterized in that, include: The reflectance characterization value of each monitoring point is obtained; the reflectance characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit; The reflectance values ​​of each monitoring point are used to determine the estimated reflectance values ​​of each control area; Based on the reflection estimates and target reflection indices of each control area, the updated driving parameters of the control area are generated, and the updated driving parameters are constrained using a constraint strategy to obtain the constrained target driving parameters. The illumination subunit corresponding to the target control area is driven to emit light by the target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified. The process of obtaining the reflectance characterization value for each monitoring point includes: Each monitoring point's control area is controlled to emit light in a first driving state and a second driving state, respectively, to obtain a first sampled value corresponding to the first driving state and a second sampled value corresponding to the second driving state; the brightness of the control area in the first driving state is higher than the brightness of the control area in the second driving state. Based on the first sampled value, the second sampled value, the ambient reference light, and the driving parameters of the control area where the monitoring point is located, an initial characterization value for the monitoring point is generated. The initial characterization value of each monitoring point is processed by time-domain filtering to obtain the reflection characterization value of each monitoring point.

2. The front light control method according to claim 1, characterized in that, Using the reflectance characterization value of each monitoring point, the estimated reflectance values ​​for each control area are determined, including: When determining the reflection estimate of the target control area, identify each target monitoring point that has a mapping relationship with the target control area; Two-dimensional linear interpolation is performed using the reflection characterization values ​​of each target monitoring point and the distance weights of each target monitoring point to obtain the reflection estimate of the target control area; the distance weights of the target monitoring points are inversely proportional to the distances of the target control area from each target monitoring point.

3. The front light control method according to claim 2, characterized in that, Based on the reflection estimates and target reflection indices for each control area, the updated driving parameters for the control areas are generated, including: Calculate the reflection error based on the target reflection index and reflection estimate of each control area; The driving update amount of each control region is calculated using the reflection error, error mapping function, and gain coefficient of each control region. By using the drive update amount, original drive parameters, and upper and lower limits of drive parameters for each control region, the updated drive parameters for the control region are determined.

4. The front light control method according to claim 2, characterized in that, The updated driving parameters are constrained using a constraint strategy, resulting in the constrained target driving parameters, including: Apply constraint policies to the updated driving parameters; if the updated driving parameters satisfy each constraint policy, then use the updated driving parameters as the constrained driving parameters; if the updated driving parameters do not satisfy the constraint policies, then use the constraint policies to adjust the driving parameters that do not satisfy the constraint policies to obtain the constrained target driving parameters. The constraint strategy includes at least one of the following: rate of change constraint strategy, hysteresis strategy, smoothing filtering strategy, and power budget constraint strategy.

5. The front light control method according to claim 1, characterized in that, Before obtaining the reflectance characterization value for each monitoring point, the following steps are also included: The entire display area of ​​the electronic paper device is divided into multiple control areas, and a first mapping relationship is established between each lighting subunit and each control area; a second mapping relationship is established between each monitoring point and each control area. The target reflectance index of each control area is determined using preset factors; the preset factors are at least one of the following: the overall brightness level set by the user, the current ambient light level, the electronic paper device mode, and the statistical characteristics of the display content of the electronic paper device.

6. The front light control method according to any one of claims 1 to 5, characterized in that, After driving the corresponding lighting subunit to emit light, it also includes: Determine if the triggering condition is met; If so, continue with the step of obtaining the reflection characterization value of each monitoring point; The triggering conditions include: environmental change events, occlusion events, and fixed-period triggering instructions; the environmental change event is: the number of first change monitoring points exceeds a first quantity threshold; the first change monitoring points are monitoring points where the reflectance characterization values ​​change in the same direction and the magnitude of the change exceeds a first magnitude threshold; The occlusion event is defined as follows: the number of second change monitoring points is less than the second quantity threshold, and the control area corresponding to the second change monitoring point is spatially continuous; the second change monitoring point is defined as the decrease in the reflectance value exceeds the second amplitude threshold, and the first quantity threshold is greater than the second quantity threshold.

7. A front light control device for an electronic paper device, characterized in that, include: The acquisition module is used to acquire the reflection characterization value of each monitoring point; the reflection characterization value is used to reflect the reflected light intensity state of the corresponding control area; wherein, the entire display area of ​​the electronic paper device includes each control area, and each control area has a corresponding monitoring point and illumination sub-unit; The determination module is used to determine the estimated reflection value of each control area using the reflection characterization value of each monitoring point; The parameter generation module is used to generate updated driving parameters for each control area based on the reflection estimate and target reflection index of each control area. The constraint module is used to constrain the updated driving parameters using constraint strategies to obtain the constrained target driving parameters. The driving module is used to drive the illumination subunit corresponding to the target control area to emit light through target driving parameters corresponding to the target control area; the target control area is the area where the driving parameters are to be modified. Specifically, the acquisition module is used for: Each monitoring point's control area is controlled to emit light in a first driving state and a second driving state, respectively, to obtain a first sampled value corresponding to the first driving state and a second sampled value corresponding to the second driving state; the brightness of the control area in the first driving state is higher than the brightness of the control area in the second driving state; an initial characterization value for the monitoring point is generated based on the first sampled value, the second sampled value, the ambient reference light, and the driving parameters of the control area where the monitoring point is located; the initial characterization value of each monitoring point is subjected to time-domain filtering to obtain the reflection characterization value of each monitoring point.

8. An electronic paper device, characterized in that, include: Memory, used to store computer programs; A processor, configured to implement the steps of the front light control method as claimed in any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the front light control method as described in any one of claims 1 to 6.

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