Power loss for full-range local dimming (FALD) displays

Abstract

A controller configured to minimize power loss in a full-area local dimming (FALD) display. The controller is configured to perform the following steps: determine an input grayscale value for each of the multiple pixels that make up the image; remap the input grayscale values ​​to output grayscale values; display the image according to the output grayscale values; and control the normalized backlight brightness for each lighting zone according to the maximum grayscale value determined for each lighting zone.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 488,843, filed on 7 March 2023, which is incorporated herein by such reference in its entirety.

[0002] [Technical field] This disclosure relates to the management of power loss in displays, for example, to the management of power loss for full-area local dimming (FALD) displays, but is not limited to this. [Background technology]

[0003] Liquid crystal displays (LCDs), thin-film transistor liquid crystal displays (TFT LCDs), TFT displays, or other types of displays may rely on backlighting to enhance image resolution, intensity, brightness, etc. Those skilled in the art may generally recognize edge lighting and full-area local dimming (FALD) as two more common types of backlighting systems. Edge-lit backlights consist of a light guide plate that can be operated to extract light from the outer periphery or edges to uniformly backlight the display, meaning the entire display can be illuminated with equal brightness throughout. FALD backlights, on the other hand, have multiple lighting zones directly behind the entire display, and the brightness of each lighting zone can be controlled independently. Independently controllable lighting zones can provide non-uniform or different amounts of brightness to individual segments of the display. The amount of backlighting required may depend on the image presented within the display, which in the case of a video display may correspond to multiple sequentially presented image frames.

[0004] Because edge-lit backlighting systems lack the ability to selectively control the brightness of different segments of a display, FALD backlighting systems can achieve relatively large power savings by independently and selectively controlling brightness across multiple lighting zones, and can even have different brightness levels in different lighting zones simultaneously if necessary. Therefore, unlike edge-lit backlighting systems, FALD backlighting systems can individually manage the brightness of each lighting zone, and as a result, can selectively minimize brightness, and consequently power loss, when it is unnecessary for the image associated with that lighting zone. [Overview of the project]

[0005] One non-limiting aspect of the present disclosure relates to the management of power loss for a display system having a function for variable brightness control, for example, a full-area locally dimmed (FALD) display having a backlight configured to variably control brightness according to a plurality of individual lighting zones. Each lighting zone is individually and separately controlled to provide the minimum amount of light necessary to backlight the corresponding portion of the display, thereby minimizing power consumption and maximizing energy savings.

[0006] One non-limiting aspect of the present disclosure relates to a full area local dimming (FALD) display. The display may include a liquid crystal display (LCD) and a backlight having a plurality of light emitting diodes (LEDs) configured to backlight the LCD. The LEDs may be arrayed according to a plurality of zones. The display may further include a display controller configured to perform a process of identifying an image displayed on the LCD, a process of determining an input gray scale value for each of a plurality of pixels constituting the image, a process of remapping the input gray scale value to an output gray scale value, and a process of controlling the LCD to display the image according to the output gray scale value. The display may further include a backlight controller configured to determine a maximum gray scale value for each of a plurality of illumination zones, and optionally, to correspond the maximum gray scale value for each illumination zone to the maximum value of the input gray scale values therein, and to control the normalized backlight luminance for each illumination zone according to the maximum gray scale value determined for each illumination zone.

[0007] The display controller can be configured to remap the input gray scale value for each zone according to a remapping function expressed as follows.

[0008]

Equation

[0009] Here, GS N corresponds to the output gray scale value, GSo corresponds to the input gray scale value, B corresponds to the gray scale bit level of the LCD, GSomax corresponds to the maximum gray scale value of the input gray scale values for the corresponding one of the plurality of illumination zones, γ corresponds to the transmittance gamma coefficient of the LCD, and γ i corresponds to the intensity gamma coefficient.

[0010] The backlight controller can be configured to determine the normalized backlight luminance of each lighting zone for each zone according to a luminance function represented as follows.

[0011]

Equation

[0012] Here, I N corresponds to the normalized backlight luminance.

[0013] The display can include the following (features):

[0014] That is, B = (2) n -1.

[0015] Here, n is the number of bits assigned to each pixel.

[0016] Each pixel can include a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and optionally, remapping can be performed for each sub-pixel.

[0017] The display can include the following (features):

[0018] That is, when the grayscale bit level is 8, n = 8.

[0019] The display can include the following (features):

[0020] That is, γ is equal to γ i to.

[0021] The display can include the following (features):

[0022] That is, 1 < γ i ≤ γ.

[0023] The display controller may be configured to remap the input grayscale values ​​zone by zone such that the input grayscale values ​​within each of the multiple lighting zones increase proportionally until at least one pixel reaches the maximum possible grayscale value.

[0024] One non-limiting aspect of this disclosure relates to a method for minimizing power loss in a full-area locally dimmed (FALD) display. The FALD display may include a display configured to display an image and a backlight having a plurality of illumination zones configured to backlight the display. The method may include the steps of determining an input grayscale value for each of a plurality of pixels constituting an image, remapping the input grayscale values ​​to an output grayscale value, displaying the image according to the output grayscale value, and determining a maximum grayscale value for each of the plurality of illumination zones, optionally relating the maximum grayscale value for each illumination zone to the maximum input grayscale value within it, and controlling the normalized backlight brightness for each illumination zone according to the maximum grayscale value determined for each illumination zone.

[0025] The method may include the step of determining the normalized backlight luminance for each lighting zone according to a luminance function expressed as follows:

[0026]

number

[0027] Here, I N γ corresponds to backlight brightness, B corresponds to the grayscale bit level of the display, GSomax corresponds to the maximum grayscale value of the input grayscale value for the corresponding of the multiple lighting zones, and γ i This corresponds to the intensity gamma coefficient.

[0028] The method may include the step of remapping the input grayscale value for each zone according to a remapping function represented as follows.

[0029] [Number]

[0030] Here, GS N corresponds to the output grayscale value, GSo corresponds to the input grayscale value, and γ corresponds to the transmittance gamma coefficient of the display.

[0031] The method can include the following (features):

[0032] That is, B = (2) n -1.

[0033] Here, n is the number of bits assigned to each pixel.

[0034] The method can include the following (features):

[0035] That is, 1 < γ i ≦ γ.

[0036] The method may further include the step of remapping the input grayscale value for each zone such that the input grayscale values within each illumination zone are proportionally increased until at least one pixel reaches the maximum possible grayscale value.

[0037] One non-limiting aspect of the present disclosure relates to a controller for a full-area locally dimmed (FALD) display. The controller includes a computer-readable storage medium storing a plurality of non-temporary instructions, which, when executed by the controller's processor, can be operated to perform the steps of: determining an input grayscale value for each of a plurality of pixels constituting an image to be displayed on the display; remapping the input grayscale values ​​to output grayscale values; displaying the image according to the output grayscale values; and determining a maximum grayscale value for each of a plurality of illumination zones constituting the backlight of the display, and optionally, the maximum grayscale value for each illumination zone may correspond to the maximum input grayscale value for that illumination zone, and the normalized backlight brightness of each illumination zone may be controlled according to the maximum grayscale value determined for that illumination zone.

[0038] The non-temporary instruction may be operable to remap input grayscale values ​​zone by zone according to a remapping function expressed as follows:

[0039]

number

[0040] Here, GS N corresponds to the output grayscale value, GSo corresponds to the input grayscale value, B corresponds to the grayscale bit level of the display, GSO corresponds to the maximum grayscale value of the input grayscale value for the corresponding of the multiple illumination zones, γ corresponds to the transmittance gamma coefficient of the display, γ i This corresponds to the intensity gamma coefficient.

[0041] The non-temporary instruction may be operable to determine the normalized backlight brightness for each zone according to a brightness function expressed as follows:

[0042]

number

[0043] Here, I N This corresponds to the backlight brightness.

[0044] A controller can include the following features:

[0045] That is, B=(2) n -1.

[0046] Here, n is the amount of bits allocated to each pixel.

[0047] A controller can include the following features:

[0048] That is, 1 < γ i ≤γ.

[0049] The aforementioned features and advantages of this instruction, as well as other features and advantages, will be readily apparent from the following detailed description of modes for carrying out this instruction when interpreted in relation to the accompanying drawings. Even if the following drawings and embodiments can be described separately, it should be understood that any single feature of them can be combined into additional embodiments.

[0050] The attached drawings are incorporated into and constitute part of this specification, illustrating embodiments of the present disclosure and serving to illustrate the principles of the present disclosure in conjunction with this description. [Brief explanation of the drawing]

[0051] [Figure 1] A partial perspective view of a vehicle having multiple displays is shown in one non-limiting aspect of the present disclosure.

[0052] [Figure 2] A schematic diagram of a display is shown, in one non-limiting aspect of this disclosure.

[0053] [Figure 3] A schematic diagram of a display element is shown, according to one non-limiting aspect of this disclosure.

[0054] [Figure 4] A schematic diagram of a backlight is shown in one non-limiting aspect of this disclosure.

[0055] [Figure 5] A normalized zone intensity plot is shown, according to one non-limiting aspect of this disclosure.

[0056] [Figure 6] A grayscale remapping plot is shown, according to one non-limiting aspect of this disclosure.

[0057] [Figure 7] A flowchart illustrating a method for minimizing wasted power losses, in one non-limiting aspect of this disclosure, is shown. [Modes for carrying out the invention]

[0058] Where necessary, detailed embodiments of the present disclosure are disclosed herein, but it should be understood that the disclosed embodiments are merely examples of the disclosure, which may be embodied in various alternative forms. The drawings are not necessarily to scale, and some features may be exaggerated or minimized to illustrate the details of certain components. Accordingly, the specific structural and functional details disclosed herein should be construed not as limiting but merely as representative grounds to teach those skilled in the art to employ the present disclosure in various ways.

[0059] Figure 1 shows a partial perspective view of a vehicle 10 having multiple displays 12 in one non-limiting aspect of the present disclosure. The vehicle 10 is shown for non-limiting purposes as an automobile having multiple displays 12 arranged within a dashboard 14, which demonstrates the advantageous function of the present disclosure for managing power loss in environments where it may be beneficial to minimize power consumption and maximize energy savings. Although the vehicle 10 is described as an automobile, the present disclosure also fully intends to include other types of displays 12 and display arrangements, including those found in trucks, motorcycles, ships, trains and / or aircraft, and / or, but not limited to, those found as part of stationary non-vehicle objects such as televisions, billboards, kiosks and / or large tents. The displays 12 are described primarily for illustrative and non-limiting purposes as being configured as full-area locally dimmed (FALD) displays, and the present disclosure fully intends to include their use and applications in other types of displays having the ability to selectively, individually, independently, separately or otherwise separately control the backlight brightness.

[0060] Figure 2 shows a schematic diagram of a display 12 according to one non-limiting aspect of the present disclosure. The display 12 may include a transmissive display screen or display element 24 that is electrically connected to a controller circuit 22 and positioned relative to a backlight 26. Optical signals 28 can be presented from the surface 30 of the display 12 to transmit visible images, data, information, words, numbers, pictures, graphic shapes, video, and other media, such as video (e.g., video from a rear-view camera, video from a front-view camera, onboard DVD player, etc.). Display signals (e.g., D) can be generated by the controller circuit 22 and received by the display element 24, which can be used to provide, for example, the presentation of instruments (e.g., speed, tachometer, fuel, temperature, etc.). Display signals D can convey information used by the display element 24 to modulate the optical signals 28. The controller circuit 22 may be configured to generate illumination signals (e.g., I) for controlling the backlight 26. The controller circuit 22 can generate and present brightness, luminance, and other information contained in the illumination signal I.

[0061] The controller circuit 22 may include one or more microcontrollers, such as a backlight controller or display controller, as described later, and may optionally include one or more processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or dedicated electronic control units implemented as separate processing units. The microcontroller may be implemented in hardware, software running in hardware, or a combination of both, and the microcontroller may also include tangible non-temporary memory (read-only memory in the form of optical, magnetic, and / or flash memory). Computer-readable and executable instructions embodying this disclosure may be stored in memory and executed by the relevant processor as described herein. Executable instructions may also be a set of non-temporary instructions used to execute an application on the microcontroller. The microcontroller may receive commands and information from various controls or components in the form of one or more input signals, etc., and control the transparent element 24 in response to one or more control signals transmitted to the display 12.

[0062] The display element 24 can be configured to implement a display panel that modulates light emitted from the backlight 26 as light passes from one side of the display element 24 to the other. The display element 24 may be a color display element 24 or a monochrome display element 24. The display element 24 can be mounted adjacent to (or next to) the backlight 26. The display element 24 operates to change opacity, color, brightness, etc., in different regions in response to a display signal D, and optionally, the changes can generally modulate the intensity and color to generate an optical signal 28. The modulated light can form an image in the optical signal 28. In various embodiments, the display element 24 can be implemented as a liquid crystal display (LCD), a thin-film transistor liquid crystal display (TFT LCD), a TFT display, or other types of displays. By implementing other display element 24 technologies, design criteria for specific applications can be met.

[0063] Figure 3 shows a schematic diagram of a display element 24 according to one non-limiting aspect of the present disclosure. The display element 24 may consist of a plurality of pixels 30, each individually indicated by a circle. The pixels 30 may be individually controlled in response to a display signal D, such as in response to corresponding current control and / or voltage control. The pixels 30 may correspond to LEDs or other devices capable of facilitating the color operation intended herein. Each pixel 30 may include a plurality of subpixels (unsigned). The pixels 30 may be of an RGB type, for example, having red subpixels, green subpixels, and blue subpixels. The display signal D may include a color value suitable for controlling the color output of each pixel 30, depending on the grayscale value selected for each of the corresponding subpixels. Thus, the display signal D may be configured to define a grayscale value for each subpixel, depending on the image 32 or a portion thereof that is to be displayed. Each subpixel may be individually controlled to facilitate the corresponding pixel 30 producing the desired color in the corresponding portion of the image 32 that is to be displayed. Image 32 is shown having a brighter central portion 34 surrounded by a darker portion to demonstrate an exemplary scenario in which the portion of the display element 24 has no image (i.e., black) or otherwise contains only a minimal amount of color.

[0064] The number of pixels 30 constituting the display element 24 can be varied according to the desired resolution, some of which include a Full HD display with 2,073,600 pixels 30 arranged in a 1920 × 1080 pixel pattern, and a 4K display with 8,294,400 pixels 30 arranged in a 3840 × 2160 pixel pattern. The colors that can be presented by the display element 24 can be determined based on color depth or bit depth, which can be defined as the number of bits per pixel (bpp) or bit level. The bit level can be used to represent the color components that can be generated by each pixel 30, which can be varied according to the function of the pixel 30. One non-limiting aspect of the present disclosure is that the display signal D is intended to represent the color generated by each subpixel by setting a grayscale value for each of those subpixels. Two more common bit levels may be that each subpixel can operate at 8-bit level, 10-bit level, etc., and the display element 24 may operate at 24-bit level, 30-bit level, etc., on a pixel-by-pixel basis. For subpixels that can operate at 8-bit level, the corresponding grayscale value may range from 0 to 255, and for subpixels that can operate at 10-bit level, the corresponding grayscale value may range from 0 to 1023.

[0065] Figure 4 shows a schematic diagram of a backlight 26 according to one non-limiting aspect of the present disclosure. The backlight 26 may consist of a plurality of LEDs or other illuminating sources 36 that can be individually controlled by an illumination signal I. The LEDs 36 may be arranged according to a plurality of illumination zones 38, each of which may contain one or more LEDs 36. Multiple dashed lines are shown for the purpose of defining the plurality of illumination zones 38. Although other configurations may be used, each of the plurality of illumination zones 38 may contain an equal number of LEDs 36, and optionally, the number of LEDs 36 in each illumination zone 38 may be less than the number of pixels 30 contained in the corresponding segment 40 of the display element 24. The corresponding segment 40 of the display element 24 may similarly be defined according to multiple dashed lines (Figure 3). The luminance signal I may include luminance values ​​for each illumination zone, thereby normalized backlight luminance values ​​may be generated separately for each zone, for example by controlling the current and / or voltage used to power the LEDs 36 in that illumination zone. The normalized luminance values ​​set for each zone 38 can be used to define the intensity, brightness, etc., of the LEDs 36 within each zone 38, so that the LEDs 36 within each zone 38 can produce the same amount of luminance for backlight illumination.

[0066] One non-limiting aspect of this disclosure attempts to manage the power loss of the display 12 by minimizing the power consumed when the backlight 26 illuminates the display elements, and optionally does so on a zone-by-zone basis, thereby setting normalized luminance values ​​for each of the multiple illumination zones 38. The ability to individually determine normalized luminance values ​​may be beneficial in that it enables the power loss techniques of this specification to provide the minimum amount of illumination necessary to satisfy the desired color depth for the corresponding segments of the display elements 24. Another non-limiting aspect of this disclosure attempts to manage the power loss of the display 12 by selectively controlling the grayscale value for each subpixel depending on the relevant illumination zone 38, thereby minimizing power loss and maximizing energy savings by coordinating the color rendering of subpixels within each segment of the display elements 24 backlit by each of the multiple illumination zones 38 with its backlight illumination.

[0067] To accurately predict the backlight power supply for each lighting zone 38, this disclosure attempts to develop a predictive equation using the concept of zone intensity which may be directly proportional to the backlight power. The luminance of a subpixel can be described according to Equation 3-1.

[0068]

number

[0069] Here, L RGB This corresponds to the brightness of each subpixel, L Backlight It supports backlight brightness 26, K RGB This corresponds to the transmittance coefficient of each subpixel, GS RGBThis corresponds to the grayscale value of each subpixel. The FALD controller 22 can be configured to use the concept of video extension, which allows it to reduce the zone brightness to the minimum brightness required to support the highest brightness pixel 30 illuminated by the backlight by the corresponding zone. This can be partially achieved by remapping each grayscale value of the pixel 30 based on the portion of the image displayed by the pixel 30. For example, if the highest grayscale in a zone is 200, the original desired brightness can be obtained by reducing the brightness and remapping GS=200 to GS=255. To simplify the analysis, a normalized backlight brightness 1 can be performed according to Equation 3-2.

[0070]

number

[0071] Here, GS N corresponds to the output grayscale value, GSo corresponds to the input grayscale value, B corresponds to the grayscale bit level of display element 24, GSOmax corresponds to the maximum grayscale value for the corresponding zone among multiple zones, γ corresponds to the transmittance gamma coefficient of display element 24, γ i corresponds to the intensity gamma coefficient. B can be the grayscale bit level of the display element 24, which is, for example, B=(2) n It can be defined as -1, where n is the bit level, for example, 8, 10, etc.

[0072] This is the last item.

number

[0073] By omitting term B, we obtain equation 3-3.

[0074]

number

[0075] GS N Solving this equation, we can replace equation 3-3 with equation 3-4.

[0076]

number

[0077] GS N Solving this equation yields equation 3-5.

[0078]

number

[0079] Therefore, the remapping gain of grayscale

number

[0080]

number

[0081] By manipulating equation 3-6 according to the laws of exponents, we obtain equation 3-7.

[0082]

number

[0083] Two GS Omax The terms can be combined according to Equation 3-8.

[0084]

number

[0085] Next, equation 3-8 can be simplified to equation 3-9.

[0086]

number

[0087] Equation 3-5 can be reproduced as Equation 3-10.

[0088]

number

[0089] The normalized zone intensity can be determined according to Equation 3-11, as well as from the last term of Equation 3-2.

[0090]

number

[0091] Equations 3-9, 3-10, and 3-11 can be used to establish the basis for the video extension function of the display element, using γi in the range of 0 to γ, which can be optionally used. γi can range from 0 to the display gamma γ, but it may be useful to consider three typical examples.

[0092] γi =0 (Case 1)

[0093] γ i =1 (Case 2)

[0094] γ i =γ (Case 3)

[0095] The first example is γ i When = 0, equation 3-10 becomes equation 3-12, equation 3-9 becomes equation 3-13, and equation 3-11 becomes equation 3-14. Case 1 corresponds to a gain of 1, and no grayscale remapping is performed.

[0096] GS N =GS O (3-12)

[0097] GS Nmax =GS Omax (3-13)

[0098] The second example is γ i When = 1, equation 3-10 becomes equation 3-14, equation 3-9 becomes equation 3-15, and equation 3-11 becomes equation 3-16.

[0099]

number

[0100]

number

[0101]

number

[0102] The third case is γ iWhen =γ, equation 3-10 becomes equation 3-17, equation 3-9 becomes equation 3-18, and equation 3-11 becomes equation 3-19. As can be seen from these, case 3 may be the most power-efficient, but it may also have the largest grayscale remapping gain.

[0103]

number

[0104]

number

[0105]

number

[0106] Figure 5 shows a normalized zone intensity plot 50 according to one non-limiting aspect of the present disclosure. Assuming B=255, from this plot the most inefficient system (blue line) is γ i This is the case when =0, because the zone brightness is set to the maximum value regardless of the maximum grayscale GSOmax within the zone. The most efficient system (gray line) is γ i This is the case where =γ, because the zone brightness is set to the minimum possible intensity value, and the largest gray gradation within the zone is remapped to GS=255 using the remapping gain of the largest gray gradation. The intermediate compromise line (orange line) is γ i This is the case where = 1.

[0107] Figure 6 shows a grayscale remapping plot 52 in one non-limiting aspect of the present disclosure. The plot shows the GS of a certain zone. Omax This example uses a grayscale level of 200, and when γi=0, the input grayscale level is GS. O =200 is GS N Since it is mapped to =200, no power is saved, and when γi=1, the input grayscale GS O=200 is GS N It is mapped to =223, and according to Figure 5, a 20% power saving is achieved at input grayscale 200, and when γi=γ, input grayscale GS O =200 is GS N This is mapped to =255, resulting in approximately 40% power savings at an input grayscale level of 200, as shown in Figure 5.

[0108] Figure 7 shows a flowchart 70 of a method for minimizing power loss for a display, according to one non-limiting aspect of the present disclosure. The method can be implemented by configuring a controller 22 together with a display controller and a backlight controller, and defining its operation and processes according to a set of controllers 22 and / or corresponding non-transient instructions. The method envisions a controller 22 or more specifically a display controller that is sufficiently capable of processing images, videos (i.e., sequences of images) and other media for presentation via a display element 24, but a separate media player, etc., may communicate with the controller 22 to facilitate some or all of the processing described herein. The method is primarily described with respect to a single instance of a displayed image 32, but the processing related to image 32 can be rapidly repeated to implement the display of a moving image or a display of multiple images as a video, etc.

[0109] Block 72 relates to a step in which the display controller performs an identification process for identifying an image 32 to be displayed on the display element 24. Block 74 relates to a step in which the display controller performs an input grayscale process for determining the input grayscale value of each of a plurality of pixels 30 used to display the image 32. This process may include a step of processing or otherwise evaluating a raw image or other image received in its original state, such as from an image source in the vehicle 10 or elsewhere, before it is processed in accordance with the disclosure for display. Block 76 relates to a step in which the display controller performs a remapping process, thereby remapping the input grayscale value of the image 32 to an output grayscale value. The remapping process may be performed at a per-pixel level, thereby remapping the grayscale value for each subpixel associated with a pixel from the input grayscale value to the output grayscale value, subpixel by subpixel. The remapping process may correspond to the display controller remapping the pixels associated with each lighting zone 38 such that at least one pixel 30 in each lighting zone 38 has a maximum possible grayscale value, such as 255 or 1023. The remapping process can be optionally performed for each lighting zone 38 according to the remapping function defined in equation 3-10 above.

[0110] Block 80 allows the display controller to control the display element 24 to display an image 32 according to the output grayscale value in relation to the display process. This allows the correspondingly displayed image 32 to be defined according to the coloration associated with the output grayscale value determined for each illumination zone 38, subpixel by subpixel, relative to the input grayscale value set for the image 32 when received by the display 12. In response to remapping the input grayscale value to the output grayscale value and then displaying the image 32, the segment 40 of the display element 24 may have a different grayscale value than that specified in the initially received image 32. This remapping can be performed additionally for the segment 40 of the pixels 30 positioned for each illumination zone 38, thereby allowing the remapping to be performed zone by zone 38 to maximize scaling up to a desired level of coloration in the illumination zone (maximum levels such as 255 or 1023 for illustrative purposes).

[0111] The function of this disclosure to remap the grayscale value of each pixel 30 to the lower lighting zone 38 may be beneficial in proportionally reducing the power used when backlighting. In other words, the function to remap the grayscale value to maximize the color of each lighting zone 38 can limit the amount of power required for backlighting the lighting zones because the color is expanded, requiring less backlighting to provide the same output image. As a result, the image 32 presented through the display element 24 can be displayed effectively with color output, brightness, etc. that match the image 32 received by the display, while with less power loss than would be required if the grayscale value were not remapped according to the lower lighting zone 38. An additional function of this disclosure to adjust the normalized backlight brightness of each of the multiple lighting zones 38 may be even more beneficial in that it allows for the power consumed when backlighting each zone 38 to be minimized to the maximum extent according to the color of the portion of the image associated with that lighting zone.

[0112] To enable individual control of the backlight illumination generated in each of the multiple lighting zones, one non-limiting aspect of the present disclosure involves a backlight illumination controller operating in cooperation with a display controller to selectively determine a normalized backlight luminance for each of the multiple lighting zones. Block 82 relates to a step in which the backlight controller performs an illumination process to determine a maximum grayscale value for each of the multiple lighting zones 38. The maximum grayscale value within each of the multiple lighting zones 38 may correspond to the maximum value of the input grayscale value associated with that lighting zone 38. The step of determining a maximum grayscale value using the input grayscale value may be desirable to scale the backlight illumination of each lighting zone in proportion to a grayscale remapping scaled to the same maximum input grayscale value. Block 84 relates to a step in which the backlight illumination of each lighting zone 38 is performed a normalization process to control the backlight illumination of that lighting zone in accordance with the normalized backlight luminance determined for that lighting zone. The normalized backlight luminance can be determined for each lighting zone according to a luminance function which can be expressed as defined by Equation 3-11 above. The normalized backlight brightness used to control the backlight illumination of each lighting zone 38 can be timed with the corresponding image 32 so that the backlight illumination can change in coordination with changes in the displayed image 32.

[0113] The terms “comprising,” “including,” and “having” include, and thus define, the presence of the feature, step, action, element, or component being described, but do not exclude the presence or addition of one or more other features, steps, actions, elements, or components. The order of steps, processes, and actions may be changed where possible, and additional or alternative steps may be adopted. As used herein, the term “or” includes any one and all combinations of the enumerated items relating to the subject. The term “any of ~” is understood to include any possible combination of the items mentioned, including “any one” of the items mentioned. “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate the presence of at least one of the items. Unless the context clearly indicates otherwise, there may be more than one such item. Unless explicitly or clearly indicated elsewhere in light of the context including the attached claims, all numerical values ​​of parameters (e.g., numerical values ​​of quantities or conditions) should be understood to be modified in all cases by the term "about," whether or not "about" actually appears before the numerical value. Components "configured to" perform the specified functions are capable of performing the specified functions without modification, rather than merely having the potential to perform the specified functions after additional modifications. In other words, if the described hardware is explicitly configured to perform the specified functions, it is specifically selected, created, implemented, used, programmed, and / or designed for the purpose of performing the specified functions.

[0114] While various embodiments have been described, this description is intended to be illustrative rather than restrictive, and it will be apparent to those skilled in the art that many more embodiments and configurations are possible within the scope of these embodiments. Any feature of any embodiment may be used in combination with, or in place of, any other feature or element of any other embodiment, unless specifically limited. Thus, embodiments should not be limited except in view of the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims. While several modes for carrying out many aspects of this teaching have been described in detail, those familiar with the art to which these teachings relate will recognize various alternative modes for carrying out this teaching within the scope of the appended claims. All matters included in the above description or shown in the accompanying drawings are intended to be interpreted as examples and illustrations of the entire range of alternative embodiments that a person skilled in the art would recognize, based on the content included, as being structurally and / or functionally equivalent or otherwise obvious, and are not intended to be limited to the embodiments expressly depicted and / or described.

Claims

1. A full-area local dimming (FALD) display, Liquid crystal display (LCD), A backlight comprising a plurality of light-emitting diodes (LEDs) configured to backlight the LCD, wherein the LEDs are arranged in an array according to a plurality of lighting zones, It is a display controller, A step of identifying the image displayed on the LCD, The process involves determining an input grayscale value for each of the multiple pixels that make up the aforementioned image, The process of remapping the input grayscale value to the output grayscale value, A step of controlling the LCD to display the image according to the output grayscale value, A display controller configured to perform the following actions: It is a backlight controller, A step of determining the maximum grayscale value for each of the plurality of lighting zones, wherein the maximum grayscale value for each lighting zone corresponds to the maximum value of the input grayscale value for that lighting zone, A step of controlling the normalized backlight brightness of each lighting zone according to the maximum grayscale value determined for the lighting zone, A backlight controller configured to perform the following actions: A full-area local dimming (FALD) display characterized by having the following features.

2. The aforementioned display controller is [Math 1] The input grayscale values ​​are configured to be remapped zone by zone according to a remapping function expressed as follows: GS N This corresponds to the output grayscale value, GSo corresponds to the input grayscale value, B corresponds to the grayscale bit level of the LCD, GSomax corresponds to the maximum grayscale value of the input grayscale value for the corresponding of the plurality of lighting zones, γ corresponds to the transmittance gamma coefficient of the LCD, γ i This corresponds to the intensity gamma coefficient. The FALD display according to feature 1.

3. The aforementioned backlight controller is [Math 2] The system is configured to determine the normalized backlight luminance for each lighting zone according to a luminance function expressed as follows: I N This corresponds to the normalized backlight brightness. The FALD display according to feature 2.

4. B = (2) n -1, n is the amount of bits assigned to each pixel. The FALD display according to feature 3.

5. Each pixel contains a red subpixel, a green subpixel, and a blue subpixel. The aforementioned remapping is performed for each subpixel. The FALD display according to feature 4.

6. If the grayscale bit level is 8, then n = 8. The FALD display according to claim 5.

7. γ is, γ i Equivalent to The FALD display according to feature 4.

8. 1 < γ i ≤γ The FALD display according to feature 4.

9. The display controller is configured to remap the input grayscale values ​​for each of the plurality of lighting zones such that the input grayscale values ​​within each zone increase proportionally until at least one pixel reaches the maximum possible grayscale value. The FALD display according to feature 1.

10. A method for minimizing power loss in a full-area local dimming (FALD) display, The FALD display comprises a display configured to display an image, and a backlight having a plurality of lighting zones configured to backlight the display. This method is The process involves determining an input grayscale value for each of the multiple pixels that make up the aforementioned image, The process of remapping the input grayscale value to the output grayscale value, A step of displaying the image according to the output grayscale value, A step of determining the maximum grayscale value for each of the plurality of lighting zones, wherein the maximum grayscale value for each lighting zone corresponds to the maximum value of the input grayscale value for that lighting zone, A step of controlling the normalized backlight brightness of each lighting zone according to the maximum grayscale value determined for the lighting zone, A method characterized by comprising: [Request Item 11] [Number 3] The process of determining the normalized backlight luminance for each lighting zone, zone by zone, according to the luminance function expressed as follows: Furthermore, I N This corresponds to the backlight brightness, B corresponds to the grayscale bit level of the display, GSomax corresponds to the maximum grayscale value of the input grayscale value for the corresponding of the plurality of lighting zones, γ i This corresponds to the intensity gamma coefficient. The method according to the present invention, characterized by the present invention. [Request Item 12] [Number 4] The process of remapping the input grayscale values ​​for each zone according to a remapping function expressed as follows: Furthermore, GS N corresponds to the output grayscale value and GSo corresponds to the input grayscale value, γ corresponds to the transmittance gamma coefficient of the display. The method according to 11, characterized by the features described above.

13. B = (2) n -1, n is the amount of bits assigned to each pixel. The method according to 12, characterized by the features described above.

14. 1 < γ i ≤γ The method according to the present invention, characterized by the present invention.

15. The process of remapping the input grayscale values ​​for each lighting zone such that the input grayscale values ​​within each lighting zone increase proportionally until at least one pixel reaches the maximum possible grayscale value. The method according to 10, further comprising the following:

16. A controller for a full-area local dimming (FALD) display, comprising a computer-readable storage medium storing a plurality of non-temporary instructions, wherein the plurality of non-temporary instructions are executed by the controller's processor when... The process involves determining an input grayscale value for each of the multiple pixels that make up the image to be displayed on the screen, The process of remapping the input grayscale value to the output grayscale value, A step of displaying the image according to the output grayscale value, A step of determining the maximum grayscale value for each of the plurality of lighting zones constituting the backlight of the display, wherein the maximum grayscale value for each lighting zone corresponds to the maximum value of the input grayscale value for that lighting zone, A step of controlling the normalized backlight brightness of each lighting zone according to the maximum grayscale value determined for the lighting zone, It is possible to operate in such a way as to perform A controller characterized by the following features.

17. The aforementioned non-temporary order is, [Math 5] It is possible to operate to remap the input grayscale values ​​for each zone according to a remapping function expressed as follows: GS N This corresponds to the output grayscale value, GSo corresponds to the input grayscale value, B corresponds to the grayscale bit level of the display, GSomax corresponds to the maximum grayscale value of the input grayscale value for the corresponding of the plurality of lighting zones, γ corresponds to the transmittance gamma coefficient of the display, γ i This corresponds to the intensity gamma coefficient. The controller according to claim 16.

18. The aforementioned non-temporary order is, [Math 6] It is operable to determine the normalized backlight brightness for each zone according to a brightness function expressed as follows: I N This corresponds to the backlight brightness. The controller according to feature 17.

19. B=(2) n -1 n is the amount of bits assigned to each pixel. The controller according to feature 18.

20. 1 < γ i ≤γ The controller according to feature 19.

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