KR102130667B1 - Electronic display with environmental adaptation of location-based display characteristics - Google Patents

Abstract

Exemplary embodiments of the present invention provide an electronic display having a display controller electrically connected to the electronic display, the display controller allowing the electronic display to input any input from the ambient light sensor if the current time is between sunrise and sunset. It also operates according to night commands without acceptance, and if the current time is between sunset and sunrise, causes the electronic display to operate according to daytime commands without accepting any input from the ambient light sensor. The nighttime commands can include a first setting for gamma, and the daytime commands can include a second setting for gamma. Sunrise and sunset transition periods can be calculated using artificial ambient sensor data (AAS) data, and additional settings for the selected gamma are possible based on the AAS data.

Description

Electronic display with environmental adaptation of location-based display characteristics

Cross reference of related applications

This application claims the priority of U.S. Provisional Application No. 62/206,050 filed on August 17, 2015 and U.S. Provisional Application No. 62/314,073 filed on March 28, 2016, all of which are incorporated herein by reference in their entirety. Is quoted as This application is also part of the continuation of U.S. Application No. 15/043,100 filed February 12, 2016 and U.S. Application No. 15/043,135 filed February 12, 2016, both of which are filed in U.S. Provisional Application No. 62 / 161,673, all of which are incorporated herein by reference in their entirety.

Exemplary embodiments disclosed herein relate to a display and method that uses measured or calculated characteristics of a viewing environment to automatically change the visual characteristics of the display according to a set of predefined rules. Some embodiments provide an autonomous display that shows an optimal visual perception for image reproduction under all environmental viewing conditions.

Displays include entertainment (e.g. television, e-books), advertising (e.g. shopping malls, airports, billboards), information (e.g. automotive, avionics, system monitoring, security), cross-applications (e.g. computers, smartphones). Used in a variety of applications. As such, displays are generally subject to a wide range of viewing environments, and in many applications the viewing environment of the display is not constant.

Exemplary embodiments disclosed herein utilize luminance-based, location- and/or time-based determinations of environmental conditions in association with stored characteristic display data to dynamically and (by real-time) process and modify an image and/or video signal to achieve luminance, black Levels, gamma, saturation, hue and sharpness are optimally recognized, which are tuned to their best intended rendering for given viewing conditions. Other embodiments provide a method of performing dynamic performance processing as well as a method of adjusting the display to perform as described.

The foregoing and other features and advantages of the present invention will become apparent from the following more detailed description of specific embodiments, as shown in the accompanying drawings.
A better understanding of the exemplary embodiments will be obtained by reading the following detailed description and accompanying drawings, and like reference numerals refer to like parts.
1 is a graphic representation of a typical image reproduction process.
2 is a block diagram of signal encoding and decoding processing.
3 is a graphical representation of image signal conversion according to ITU-R BT.709/1886.
4 is a graphical representation of end-to-end power versus ambient light.
FIG. 5 is a graphical representation of end-to-end 멱 vs. ambient illuminance in a discrete implementation.
6 is a block diagram of the basic elements of an embodiment of the present invention.
7 shows the relationship between the reflected ambient light and its displayed light.
8 is a logical flow diagram for performing an exemplary embodiment of location-based determinations of ambient conditions.
9 is a block diagram of an embodiment using post-decoding adjustment of black level and/or linearity.
10 is a graphical representation of the example signal transforms of FIG. 8 using Equation 2.
11 is a block diagram of an alternative embodiment for post-decoding adjustment.
12 is a block diagram of an embodiment for pre-decoding adjustment of black level and/or linearity.
13 is a graphical representation of the exemplary signal conversion of FIG. 11 using Equation 4.
14 is a graphical representation of the example signal transforms of FIG. 11 using Equation 5.
15 is a graphical representation of the example signal transforms of FIG. 11 using Equation 6.
16 is a graphical representation of the example signal transforms of FIG. 11 using Equation 7.
17 is a detailed view of the lower left corner of FIG. 15.
18 provides a logic flow diagram for performing an embodiment using the AAS technique during the sunset/sunrise transition time while using the night/day level for the remaining time.
19 provides a logic flow diagram for performing embodiments using AAS technology having only a single transition period while using night/day instructions for the remaining time.
20 provides a logical flow chart for performing an improved embodiment using AAS technology during daylight hours as well as sunset/sunrise transition times while considering local weather information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention may be implemented in many different forms and should not be construed as limited to the exemplary embodiments described herein. Rather, these embodiments are provided to enable the present disclosure to be thorough and complete and to fully convey the scope of the present invention to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions are shown enlarged for clarity.

The terminology used herein is for the purpose of describing specific embodiments, and is not intended to limit the invention. As used herein, the singular form is intended to encompass the plural form unless the context indicates otherwise. As used herein, the terms “comprising” and/or “comprising” refer to the presence of the mentioned features, integers, steps, actions, elements and/or components, but other features, integers, steps , Does not exclude the presence or addition of one or more of the actions, elements, components and/or groups thereof.

Embodiments of the present invention are described with reference to the drawings, which are schematic diagrams of ideal embodiments (and intermediate structures) of the present invention. As such, transformations from the shape of the illustration as a result of, for example, manufacturing techniques and/or tolerances will be expected. Thus, embodiments of the invention are construed to be limited to areas of the specific shape shown herein. It should not include, for example, variations in shape resulting from manufacturing.

Unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. In addition, terms such as terms defined in commonly used dictionaries should be interpreted as having meanings consistent with meanings in the context of related technologies, and are explicitly defined herein unless interpreted as ideal or excessively formal meanings. do.

A very high level diagram of an exemplary image capture and reproduction process is shown in FIG. 1. Images typically occur in real scenes captured from video/still cameras or computer-generated scenes. The noble goal of most reproduction systems is to display the most lifelike image possible for the final human observer. There are many obstacles to doing this perfectly. In fact, some "improvements" are often intentionally added to the displayed image to improve the viewing experience. One of the main obstacles to high fidelity reproduction is that the local viewing environment of the final observer cannot be clearly predicted, but the viewing environment can have a profound effect on the visual quality of reproduction. In addition, the viewing environment can be changed almost continuously, except for a few special cases, such as the theater's strict control environment.

The subtle but very close aspect of FIG. 1 is that the total light reflected from a physical object is essentially a linear sum of the reflected light of all light sources impinging on the object. In addition, the object can also emit its own light, which is linearly added to the contribution reflected from the object to reach the total observed light. This is basically the explanation that non-coherent light operates linearly on this point (eg 1 + 1 = 2). As a result, the absolute brightness or luminance of every point in the scene is proportional to all constituent components of the light that can be traced to that point. This is the reality provided to human observers of real scenes, and is also the way computer-generated scenes are generally generated. Therefore, in theory, the display device must adhere to the principle of luminance linearity for the reproduction of the purest form. Or, in general, the entire processing chain, from the light coming from the camera to the light exiting the display, must adhere to the principle of luminance linearity. This principle will relate to various aspects of the present invention.

As mentioned above, the goal of the display is to reproduce a lifelike replica of the original scene. However, there are some unique and inevitable limitations. One such limitation is the difficulty in matching the display to the dynamic range of luminance present in the real world, especially at the top of the scale (eg, the sun and its reflections). Another limitation is that the display is a wrinkled "flat" version of the original scene. Therefore, there are a variety of "3D" techniques to create deep illusions from one or more specific points of view, but true 3D (3D) depth reproduction is not possible. It also attempts to overcome this in special venues such as the IMAX® theater, but a typical display cannot start simulating a nearly hemispherical view of the human eye. Finally, the display itself is a physical object present in some environment, and the environment itself can have a very important effect on the visual quality of reproduction.

In traditional color displays, each pixel typically consists of three sub-pixels, one for each of the primary colors such as red, green, and blue. There are displays that can use four or more sub-pixels, but the embodiments herein do not depend on the exact number of sub-pixels or colors they represent. The information content of the displayed image is a result of uniquely commanding or driving each sub-pixel, and the characteristics of the driving process are technology-dependent (eg, CRT, plasma, LCD, OLED, etc.). It should be noted that the exemplary embodiments herein can be used on any type of electronic display and are not specific to one display type. The driving level of each sub-pixel may range from pull-off to pull-on. This is the basic process by which an image is formed by a display. The full range of displayable colors (ie, color gamut) is obtained by changing the relative driving level of the sub-pixels through the full range of combinations. Non-primary colors are created when the human eye combines three sub-pixels to produce an effective blend color through controlled blending of the base color.

In the digital domain, if the sub-pixel drive level is defined as 8 digital bits, there may be a total of 2 ⁸ = 256 separate drive levels per sub-pixel. Gray level is a special case where all sub-pixels are driven at the same level (defined in VESA FPDM 2.0). This typically produces a'gray-like' color, such as full on (lowest brightness, mostly white) from pull-off (lowest brightness, mostly black). Continuing 8 bits per sub-pixel (3 sub-pixels × 8 bits = 24, also called 24-bit color), there are 2 ²⁴ = 16,777,216 possible colors, but are generated when all sub-pixels in the gray level are driven the same. For simplicity, the gray level in sub-pixel units (i.e., 256 gray levels for 8-bit control), with the tacit understanding that adjacent sub-pixels are not necessarily driven to the same level as required for color image generation. Will tell. This is because the present invention is independent of color reproduction, but is completely compatible with color reproduction.

Gamma (indicated by γ) represents the mathematical index of the power function S ^γ that transforms the gray level scaling (sub-pixel basis) in the image. Although the source of gamma processing dates back to the earliest days of vacuum tube cameras and CRT displays, it is still very relevant in modern displays for human vision to improve perceived resolution in darker areas of the image that are more sensitive to absolute changes in brightness. It is a procedure.

로 표기된 함수 블록에서 발생한다. 일반적으로(반드시 그런 것은 아니지만) 멱 함수

= (S)^a의 형태를 취한다. 역사적으로, a 지수는 감마 보정 지수로서 언급되지만, 이 논의의 목적상 보다 일반적으로 신호 인코딩 지수로서 언급될 것이다. 그런 다음, 결과적인 인코딩된 신호 S_e (= (S_s)^a) 는 디스플레이에 들어가고

로 표기된 함수 블록에 의해 디코딩되는 바, 이는 일반적으로(반드시 그런 것은 아니지만) 또 하나의 멱 함수

=(S)^γ의 형태를 취한다. 대체에 의해, 디스플레이를 구동하는 결과적인 디코딩된 신호 S_d (= (S_e)^γ) 는 Sd =(Ss) S_d = (S_s)^{a γ}를 통해 초기 소스 이미지 신호 S_s와 관련된다. 실제적으로, 위에서 설명된 비교적 단순한 변환에 대한 변수들이 있지만, 이미지 신호를 인코딩 및 디코딩하는 일반적인 처리는 동일하다는 것에 유의해야한다.The conceptually simplest image reproduction stream is shown in FIG. 2. Light from the real-world scene (L _i ) is captured by the camera to perform an optical-to-electric (O/E) conversion detector (usually a solid-state pixelation detector using CCD or CMOS technology) initial source image signal ( S _s ). This image signal is typically a voltage signal that is roughly proportional to the amount of light arriving on each pixelated detector element, but can be immediately converted to a digital signal. Alternatively, the source image signal S _s comes from a computer generated graphic that typically evolves in the linear domain in much the same way that light behaves in the real world. In both cases, the signal encoding

It occurs in a function block marked with. Normally (but not necessarily) the 멱 function

It takes the form of a = (S) ^a. Historically, the a index is referred to as the gamma correction index, but for purposes of this discussion it will more generally be referred to as the signal encoding index. Then, the resulting encoded signal S _e (= (S _s ) ^a ) enters the display

Decoded by a function block denoted by, which is usually (but not necessarily) another 멱 function

=(S) It takes the form of ^γ . By substitution, the resulting decoded signal S _d (= (S _e ) ^γ ) driving the display is related to the initial source image signal S _s through Sd =(Ss) S _d = (S _s ) ^{a γ} . It should be noted that, in practice, there are variables for the relatively simple transformation described above, but the general processing for encoding and decoding image signals is the same.

Continuing with reference to FIG. 2, the decoded image signal Sd drives the components in the display that convert the electrical image data into light emitted by the display L ₀ through electro-optical (E/O) conversion. Used to The details of E/O processing are unique to display technologies such as LCDs, plasmas, and OLEDs. In fact, in the case of the deprecated CRT technology, the decoding function f _d was an essential part of the E/O conversion process.

It should be noted that in the above discussion, the signals'S' typically represent normalized values from 0 to 1. In the case of voltage signals, the actual signals are normalized to V _MAX so that S = V _actual /V _MAX . In the case of digital signals, the signals are normalized by D _MAX to be S=D _actual /D _MAX (eg, for the 8-bit channel D _MAX =2 ⁸ = 256). Signal normalization processing is generally not shown explicitly in FIG. 2 but requires processing steps implied herein. As long as the normalized signal is used consistently, it does not matter whether the signals represent voltage levels or bit levels, both will be covered by the exemplary embodiments herein.

As a specific example of an end-to-end image processing stream, ITU-R BT.709-5 (2002) recommends encoding a television signal with a value of 0.5 (Note: this is a bit simplified of BT.709), and ITU- R BT.1886 (2011) is a γ value to 2.4 is recommended to encode the television signal end-to-end powers (ε) is ^{_{1.2: s d = s e 2}} .4 = (s s 0 .5) 2.4 = s s ( ^{0.5 x 1.2)} = _{s s} ¹ leads to ^0.2 and. The signal transformations occurring in the ITU-definition processes are shown in Figure 3, where the parameters for the horizontal'input' axis and the vertical'output' axis depend on the relevant processing step. For example, during the signal encoding operation, the horizontal axis represents S _s (as an input signal) and the vertical axis represents S _e (as an output signal). Implicit normalization of signals is evident in FIG. 3 because all signal levels are between 0 and 1.

In FIG. 3, the ITU-R BT.709/1886 signal conversion process uses the above-described principle of end-to-end brightness linearity because the end-to-end law index of the reproducing system has ε=1.2 rather than ε=1.0 as in the case of pure linearity. It should be noted that it is not strictly observed. This creates a slight curve of the black line in FIG. 3. The main reason for the departure from pure linearity is that the camera/display cannot actually reproduce the entire dynamic range of light present in the real world. As a result, an end-to-end index (or = index) of ε = 1.2 is generally considered to yield a better perceptual experience for home television viewing with an average backlight of 200 lux. This is based on reproducing more vivid image contrast when the human eye adapts to a typical home environment.

However, it is common for filmmakers to deviate from ITU-R BT.709 encoding to aim for a darker viewing environment, such as a theater with a background illumination of 1-10 lux and/or to create artistically flavored video content. The typical encoding index for this application is approximately a=0.60. When this signal is decoded with 멱 exponent γ = 2.4, the end-to-end linearity 멱 becomes ε = 1.45.

Another common image encoding method is the sRGB standard, which is intended to render images in a moderately bright environment, such as a business office with 350 lux of backlighting. sRGB requires a signal encoding index approximating a=0.45. If such an sRGB encoded signal is subsequently decoded with 멱 exponent γ = 2.4, the end-to-end linearity 멱 is ε = 1.1.

The three different viewing environments discussed above and their proposed end-to-end linearity 멱 indices can be curve-fitting and used to extrapolate to higher levels of ambient lighting. This trend is given by equation (1) plotted in FIG. 4. Thus, once the ambient illumination level I _a is measured, the desired end-to-end linearity 멱 index ε can be determined from equation (1). This relationship between I _a and ε will be closely related to certain aspects of the invention described in the next paragraph. The relationship given by equation (1) is merely representative, and the present invention does not depend on the exact form of equation (1). In general, the present invention can implement any arbitrary relationship between I _a and ε.

식(1)

Expression (1)

In Figure 4, it is noted that the desired end-to-end 멱 approaches purely linearly (i.e., ε→1) asymptotically as the ambient light increases. Above 1000 lux, 멱 ε is essentially equal to 1. This is basically a statement that the eye has to adapt to the whole daylight conditions so that the display should start to follow the principle of pure end-to-end luminance linearity as described above. However, it is rare that the display actually implements ε of ε = 1.

Alternatively, the function described by equation (1) can be implemented in a separate manner, as shown in FIG. 5. Since the number of individual levels shown in FIG. 5 is representative, various embodiments of the present invention may implement any number of individual levels according to processing power and application.

6 provides a schematic diagram of the basic components of an exemplary embodiment. Here, the environment processor 200 may obtain video data from the video source 150. The display controller 110 may include various components, including, but not limited to, a microprocessor and electronic storage (which can store adjustment data). The environment processor 200 is preferably in electrical communication with the display 300. In some embodiments, display controller 110 may be in electrical communication with video source 150 and display 300. One or more microprocessors on display controller 110 may perform any of the functions described herein.

Video source 150 is any, but not limited to, any number of generating and/or transmitting video data, including television/cable/satellite transmitters, DVD/Blu-ray players, computers, video recorders or video game systems. It can be a device. The display controller 110 can be any combination of hardware and software that uses location-based ambient environment data and modifies the video signal based on the adjustment data. The adjustment data 120 is preferably a non-volatile data storage accessible to a display controller that contains adjustment data for location-based ambient environment data and optionally includes reflection information for the display assembly. The display 300 may be any electronic device that provides an image to the viewer.

Brightness adjustment

There are many applications where the desired brightness (i.e. maximum brightness) of the display can vary, but perhaps the most obvious case is when the displays are used outdoors. In this case, the ambient light surrounding the display can vary from a dark night to a sufficient amount of sunlight at noon-a factor of approximately 7 to 10.

The behavior of the human visual system (including the eyes, optic nerve, and brain) is a very complex problem, and in fact, most of the leading experts in this field do not have sufficient consensus on parametric performance. This problem is exacerbated by the highly adaptable and nonlinear nature of the human visual system. Therefore, it is not useful in the present invention to attempt to define a specific visual function. However, there are some general points that everyone agrees. One is that the human visual system can adapt to perhaps 12 to 12 powers through a very wide range of light levels given some time for adaptation. However, there is a limit to the instantaneous dynamic range of human vision at a particular adaptation level, perhaps 2 to 3 powers of 10 (which depends on the absolute adaptation level).

The specific level of adaptation depends on the eye's integrated field of view (almost hemispherical), taking into account all viewable objects and light sources in this range. Since the display will occupy only a portion of the entire field of view, the maximum brightness of the display must be altered to accommodate the overall adaptation of human vision to various light levels, which will of course include light from the display itself. For example, a display that generates 500 candelas/square meters (nits) when viewing at night or in other dark environments (unless you get close enough to the display to fill most of your field of view and take some time for proper adaptation) It can be noticeably brighter, but the same display will be slightly dim and not impressive on a sunny day, and may actually have a lower gray level that is not discernible.

Black level and linearity adjustment

All displays reflect some ambient light. In some cases, the reflected light level can be high enough to substantially dominate the dark areas of the displayed image or video content (hereinafter simply'image'). When this occurs, the visual details of the darker areas of the image are essentially "washed out". In other words, the display cannot produce a visually identifiable luminance level in an image falling below the equivalent luminance level of the reflected ambient light. The general situation is shown in Figure 7, where RAL is the effective brightness of the reflected ambient light, and DBL is the displayed brightness of any portion of the image. Where the image's DBL <RAL is present, there will be obvious loss in the image content of those areas. An analogy is the inability to hear quieter parts of music while listening in an environment with excessive background noise. For this reason, most radio broadcasts transmit signals with compressed dynamic range for improved "perception" listening in the noisy environment of a car.

To restore the visual identification of darker areas in the image, it is possible to artificially raise the black level of the image signal so that the displayed brightness of the black level is approximately equal to the effective brightness of the reflected ambient light. This is equivalent to generating a signal-to-noise ratio >1 of all displayed light levels versus reflected ambient light. As a result, the pure black area of the original image becomes a certain level of dark gray depending on the ambient light level. That is, the dynamic range of the image is compressed.

In addition to increasing the black level, the end-to-end linearity (or gamma) of the display system can be changed to improve the contrast of gray-scale (also called tone-scale) selection areas, depending on the specific application and rendering intent. This can be based on the previous equation (l) or other defined relationship as described in FIGS. 4 and 5.

For outdoor applications and certain indoor applications, the amount of ambient light reflected from the display varies almost continuously depending on the time of day and other operating conditions (eg weather, shadowing effect, mood light, etc.). Thus, exemplary embodiments of the present invention are not limited to those discussed above, but provide a means to automatically adjust the black level and/or gamma of the display according to predefined rules.

In a darkened theater or similar environment, there is little or no ambient light reflected from the display, in which case the end-to-end linearity (gamma) of the images in certain applications (e.g. artistic freedom of digital signage). It should be noted that although changing is still desirable, there is no special need to raise the black level of the image.

The conceptually and functionally easiest position to perform autonomous black level and linearity adjustment is after the normal image signal decoding process, generally shown in FIG. In this figure, the signal flow was previously described in FIG. 2 except that a new signal processing block denoted f _p was added to the signal flow to provide automatic real-time image signal adjustment in response to changing environmental conditions. similar. Since the processing block denoted by f _p operates after the normal signal decoding processor denoted by f _d , it can be viewed as a post-decoding processor.

Determination of environmental conditions

In an exemplary embodiment, ambient environmental conditions can be determined based on the geographic location of the display, and based on a calendar date, calculates the approximate time of sunrise and sunset, and compares the current time with the ambient environmental conditions. Can decide.

8 provides a logic flow diagram for performing a first embodiment of a method that is controlled based on display position data. As an initial step in this embodiment, the system preferably determines geographic location data for the display. This can be done in a number of ways. First, the physical address of the display can be used to determine the city/state where the display is located. Second, the physical address of the display can be changed to latitude and longitude coordinates. This technique, although not limited to this, can be accomplished by accessing a number of online tools, including www.latlong.net. Third, the location of the display can be determined by reading coordinates from the GPS-enabled device 400 in the electronic display, and can form part of the display controller 110 or a separate device electrically connected to the display controller 110. Can. If the coordinates are real addresses, they can be converted to latitude and longitude coordinates using the techniques described above and vice versa.

Once the location of the display is determined, the sunset and sunrise times for this location are preferably determined. The timing of performing this step may vary. In some embodiments, this step can be performed only once, and 365 days of data is used in the display for the remainder of the life of the display. Alternatively, this step can be performed annually, monthly, weekly or daily. This step can also be performed in several ways. First, given a physical address, the system can determine the sunrise/sunset time based on this address and store it in an electronic storage on display controller 110. Second, given the latitude/longitude coordinates, the system can determine the sunrise/sunset time based on these coordinates and store them in an electronic storage on display controller 110. Location data can be converted to sunrise/sunset times by accessing any number of online databases, including but not limited to www.sunrisesunset.com, www.suncalc.net, and various NOAA online tools. In addition, the latitude and longitude data can be used to calculate the sunrise/sunset time based on the sunrise equation.

여기서,

here,

는 일출(음의 값을 취하는 경우) 또는 일몰(양의 값을 취하는 경 시간 각도이다.

Is a sunrise (if taking a negative value) or a sunset (a time taking a positive value).

　는 관측자의 지구 위도이다.

Is the observer's latitude.

　는 태양의 적위이다.

Is the declination of the sun.

Determining the geographic location data for the display and determining the approximate sunrise/sunset time based on the geographic location data can be performed electronically or manually, or before the display is shipped to the actual location. Should know. In other embodiments, the display can be installed in the actual location before performing these two steps.

Once the approximate sunrise/sunset time has been determined (and preferably stored on the display), the system will check what time the current time is and determine if the current time is the current night or day. Although this figure reads the logic as "Is the current time placed before sunrise after sunset", it is also shown that the current time can be performed by determining "whether it is placed before sunrise and sunset", which differs in any of these embodiments There is no In this first embodiment, if it is determined that the system is currently nightly, the system provides nighttime commands to the display controller 110. Alternatively, upon determining that the system is daytime, the system provides nighttime commands to the display controller 110. Generally speaking, night/day commands may simply be instructions sent to the display controller 110 (possibly from other components within the display controller 110) indicating that it is currently day/night.

Relative day and night settings and parameters for the display can be selected for this embodiment through a simple binary operation, where the first set of settings and parameters for the display are required during the night, and the second set for the display The settings and parameters of are required during the day. Thus, an appropriate gamma or black level is selected for the "night command", and another gamma or black level can be selected for the "night command", which is based on the desired relationship between ambient light and gamma or ambient It can be selected from a lookup table (similar to that shown in Figure 4 or 5) based on any other desired relationship between light and gamma or black level (or other display settings).

The dashed line in the figure represents the option of the system returning to determine the approximate sunrise/sunset time when implementing an embodiment in which this data is updated annually, monthly, weekly or daily.

In FIG. 9, the day/night indication (location-based determination of ambient conditions) is preferably a lookup table and/or operation to determine the desired display black level (and other settings discussed below) for the day/night indication. It is sent to the environmental processing unit marked'Proc' which contains the algorithm to a minimum. This environmental processing unit may be part of the display controller 110, and may use a microprocessor or a separate processor on the display controller 110. Additionally, the environment processor can communicate with an electronic storage device having a look-up table and/or computational algorithm for image signal linearity correction (eg, a power function) for day/night instructions. In addition, provisions are added to add real-time programmable instructions to the environment processor. Programmable instructions may be used in a variety of ways, including, but not limited to, altering or replacing environment-based processing depending on time of day, display content, and the like. In summary, the environmental processor output signal Sa has a signal linearity correction value that takes the form of an exponent called β here (in the case of a simple power function) depending on the instantaneous value and option of the desired display black level Sb.

9, the decoded image signal S _d and the peripheral response control signal S _a are supplied to the image signal processing block denoted by f _p , according to Equation (2) below in an exemplary embodiment. The final display driving signal S _p is generated. This equation assumes that the three image signal transformations (encoding, decoding and post decoding) are performed as exponential law functions. Signal encoding and decoding by the law function is typical in the industry, but is not a necessity for the present invention as other functions may be used with various embodiments herein. The right side of equation (2) represents the processing function f _p of the block that accepts the input signals S _a and S _d and outputs the signal S _p .

식(2)

Expression (2)

a = signal encoding 멱 exponent (assuming 멱 law encoding)

γ = signal decoding 멱 exponent (assuming 멱 law decoding)

S _b and β are included in the environmental reaction control signal S _a .

S _b = desired black level offset as a percentage of the full scale signal

β = linearity modifier 멱 exponent (assuming 멱 law correction)

If the encoding index a and the decoding index γ are known amounts as assumed in equation (2), the final end-to-end signal linearity is determined only by the value of the linearity modifier index β. That is, β is equivalent to the previously defined end-to-end linearity 멱 exponent ε. The encoding index a is typically known based on the source of the image data, and the decoding index γ is given by the manufacturer of the display and/or can be determined by testing. Equation (2) provides a specific example of the processes described in this section based on a particular method of signal encoding/decoding, but the general processing is the same as any other encoding/decoding method.

The function of equation (2) is shown in FIG. 10. Here, the encoding process is a single 멱 law transform to exponent a = 0.50 (approximate by ITU-R BT.709-5), and the decoding process is a single 로 to exponent γ = 2.40 (according to ITU-R BT.1886). It is a law transformation. In this example, the requested black level is set to 0.1 and the linearity modifier index β is set to 1.20, but generally these values will be selected by the system (preferably automatically) based on day/night indications. The effective decoding transform is given by the lower curve and the end-to-end signal transform is given by the desired black level offset of 0.1 and the intermediate curve showing a slightly inclined linearity consistent with the signal transform 멱 of ε = 1.20.

Alternatively, the function of the image signal decoding block f _d can be absorbed into the environment processor block f _p as a new processing block denoted f _dp as shown in FIG. 11.

In Fig. 11, the display driving signal S _p is formed by equation (3).

식(3)

Expression (3)

Where β * = β/γ and all other parameters are defined as before. Since Equation (3) has the same function as Equation (2), the result shown in Fig. 10 is produced.

In some cases it is more convenient or necessary to perform black level and/or linearity adjustment prior to normal signal decoding conversion. The general process is shown in FIG. 12. In this figure, it can be seen that the environmental response image signal processing function represented by f _p has been moved forward to the normal image signal decoder function represented by f _d . In this way, f _p can be considered as a pre-decoding function.

Referring to FIG. 12, the encoded image signal S _e and the environmental response control signal S _a are supplied to an image processing block denoted by f _p , which is final according to Equation (4) below in an exemplary embodiment. The display driving signal S _p is generated. This equation assumes that all three image signal transformations (encoding, pre-decoder processing and decoding) are performed with the power law function. Signal encoding and decoding by the law function is not essential in any embodiment of the present specification, but is typical in the industry. The right side of equation (4) represents the processing function of the block f _p , accepts the input signal Sa and the input signal Sa, and outputs the signal S _p .

식(4)

Expression (4)

a = signal encoding 멱 exponent (assuming 멱 law encoding)

γ = signal decoding 멱 exponent (assuming 멱 law decoding)

S _b and β are included in the environmental reaction control signal S _a .

S _b = desired black level offset as a percentage of the full scale signal

β = linearity modifier 멱 exponent (assuming 멱 law correction)

If the encoding index a and the decoding index γ are known amounts as assumed in equation (2), the final end-to-end signal linearity is determined only by the value of the linearity modifier index β. That is, β is equivalent to the previously defined end-to-end linear 멱 exponent ε. The encoding index a is typically known based on the source of the image data, and the decoding index γ is given by the manufacturer of the display and/or can be determined by testing. Equation (4) provides a specific example of the processes described in this section based on the specific method of signal encoding/decoding, but the general processing is the same as any other encoding/decoding method.

An example of the function of equation (4) is shown in FIG. 13. Here, the encoding process is a single power law transform with exponent a = 0.50 (approximate by ITU-R BT.709-5), and the decoding process is single with exponent γ = 2.40 (according to ITU-R BT.1886). 변환 Law transformation. The black level requested in this example was set to 0.1, and the linearity modifier index β was set to 1.20. The decoding transform is given by the lower curve, and the end-to-end signal transform is given by the desired black level offset of 0.1 and the intermediate curve showing slightly inclined linearity consistent with the signal transform 멱 of ε = 1.20. As expected, FIG. 13 is identical to FIG. 10 because the same black level Sb and the linear correction symbol β are requested in both cases.

The scenario described in the previous sections can be modified to maintain and/or reduce gray levels below a certain threshold. The main reason for doing this is to maintain the attractive power saving characteristics of backlight dynamic dimming in liquid crystal displays (LCDs). Dynamic dimming was covered by co-pending application No. 12/793,474 filed on June 3, 2010, the entire application of which is incorporated herein by reference.

For purposes of illustration, the embodiments described in this section will assume the pre-decoder processor shown previously in FIG. 12.

Exemplary Example 1

Referring to FIG. 12, the encoded image signal Se and the environmental response control signal Sa are supplied to an image signal processing block denoted by fp, which is a pre-decoded image according to Equation 5 below in an exemplary embodiment. Generate the signal Sp. Although this equation is not essential in the present invention, it is assumed that a total of three image signal transformations (encoding, pre-decoder processing and decoding) are performed with the power law function. Equation (5) represents the processing function of the block fp, accepts the input signals Sa and Se, and outputs the signal SP. A new feature of this embodiment is the introduction of a gray level threshold, denoted St, to derive two conditional cases expressed in equation (5). The first condition is applicable when the encoded signal level falls below the level derived from St, in which case these signal levels will be set to 0 (ie full black). The second condition of equation (5) is applicable to the encoded signal level above the level derived from St.

식(5)

Expression (5)

a = signal encoding 멱 exponent (assuming 멱 law encoding)

γ = signal decoding 멱 exponent (assuming 멱 law decoding) S _t , S _b and β are included in the environmental response control signal S _a .

St = desired gray level threshold as part of the full scale input signal

Sb = desired black level offset as part of the full scale output signal

β = linearity modifier 멱 exponent (assuming 멱 law correction)

The gray level threshold (St) is 1) an environmental response variable determined through a look-up table or a computational algorithm within a processing block marked'Proc', or 2) a'programmable command' of'Proc', or 3) a'Proc'. It can be a fixed value pre-programmed within, or 4) any combination of the above. Alternatively, St may be a fixed value within the fp value.

If the encoding index a and the decoding index γ are known quantities as assumed in Equation 5, the final signal linearity exceeding the gray level threshold St is only determined by the value of the linearity modifier index β, where β is previously defined Equivalent to the end-to-end linear 멱 exponent ε. The encoding index a is typically known based on the source of the image data, and the decoding index γ can be given by the manufacturer of the display or can be determined by testing. Equation (5) provides a specific example of the processes described in this section based on a specific method of signal encoding/decoding, but the general processing is the same as other encoding/decoding methods.

An example of the function of equation (5) is shown in FIG. 14. Here, the encoding process is a single power law transform to exponent a = 0.50 (approximate by ITU-R BT.709-5), and the decoding process is to exponent γ = 2.40 (according to ITU-R BT.1886). It is a single power law transformation. In this example, the requested black level is set to 0.1, the requested black level threshold is set to 0.05, and the linearity modifier index β is set to 1.20. The effective decoding transform is given by the lower curve, where the end-to-end signal transform is at an intermediate curve that exhibits a desired black level offset of 0.1 at a threshold of 0.05 and a slightly inclined linearity that matches the end-to-end signal transform 멱 of ε = 1.20. Is given by

Exemplary Example 2

The “cliff” type threshold cutoff generated by Eq. (5) and shown in FIG. 13 produces visual artifacts that are not deserved especially for high levels of threshold and/or black level offset in the image. This appears as a dark area of the image that suddenly turns unnaturally black, and this phenomenon is sometimes called banding, which can be reduced by softening the edges of the threshold.

Referring again to FIG. 12, the encoded image signal Se and the environmental response control signal Sa are processed in the exemplary embodiment, in fp, to generate a pre-decoded image signal Sp according to Equation 6 below. Is supplied to the block. Although this equation is not essential in the present invention, it is assumed that a total of three image signal transformations (encoding, pre-decoder processing and decoding) are performed with the power law function. Equation (6) represents the processing function of the block fp, accepts the input signals Sa and Se, and outputs the signal Sp. A new feature of this embodiment is the introduction of a gray level turn-off point denoted by So, and derives three conditional cases represented by equation (6). The first pair is applicable when the encoded signal level falls below the level derived from So, in which case these signal levels are set to 0 (ie, full black). Next, for the encoded signal level that is more than the level derived from So but a threshold level derived from St, the second condition of equation (6) is applicable. The third condition in equation (6) is applicable to the encoded signal level higher than the level derived from St. The second condition is used to smooth the transition between the raised black level and the pull off level by generating a linear ramp from the display drive signal Sd between So (drive level = 0) to St (drive level = Sb). .

식(6)

Expression (6)

a = signal encoding 멱 exponent (assuming 멱 law encoding)

γ = signal decoding 멱 exponent (assuming 멱 law decoding) St, Sb and β are included in the environmental response control signal Sa.

So = desired gray level turn-off point as part of the full scale input signal

St = desired gray level threshold as part of the full scale input signal

Sb = desired black level offset as part of the full scale output signal

β = linearity modifier exponent (assuming the modification of the exponential law)

The gray level turn-off point (So) and the gray level threshold (St) are 1) an environment-response variable determined through a lookup table or a computational algorithm in a processing block marked "Proc", or 2) programming in'Proc' Possible command' port, or 3) a fixed value pre-programmed in'Proc', or 4) any combination of the above. Alternatively, So and St may be fixed values in the fp processing block.

If the encoding index a and the decoding index γ are known quantities as assumed in Equation 6, the final signal linearity exceeding the gray level threshold St is only determined by the value of the linearity modifier index β, where β is previously defined It is equivalent to the end-to-end linear 멱 exponent ε. The encoding index a is typically known based on the source of the image data, and the decoding index γ is given by the manufacturer of the display and/or can be determined by testing. Equation (6) provides a specific example of the processing described in this section based on a specific method of signal encoding/decoding, but the general processing is the same as other encoding/decoding methods.

An example of the function of equation (6) is shown in FIG. 15. Here, the encoding process is a single power law transform to exponent a = 0.50 (approximate by ITU-R BT.709-5), and the decoding process is to exponent γ = 2.40 (according to ITU-R BT.1886). It is a single power law transformation. In this example, the requested black level offset is set to 0.1, the requested gray level turn off is set to 0.02, the gray level threshold is set to 0.05, and the linearity modifier index β is set to 1.20. The effective decoding transform is given by the lower curve, the end-to-end signal transform has a desired black level offset of 0.1, a gray level turn off of 0.02, and a gray level threshold of 0.05 and a slightly inclined linearity consistent with ε = 1.20. It is given by the middle curve shown. The linear ramp between (So, 0) and (St, Sb) serves to reduce the aforementioned banding effect.

Exemplary Example 3

In the previous embodiment, the linear ramp provided as a transition between pull-off and threshold provides a significant reduction in visual artifacts or banding, but there are still sharp points in the end-to-end conversion curve shown in FIG. 15. To further improve the transition, a specific example of using a sinusoid is described below, but other functions can also be used.

Referring again to FIG. 12, the encoded image signal Se and the environmental response control signal Sa are image signals denoted by fp generating a pre-decoded image signal Sp according to Equation 7 below in an exemplary embodiment. It is preferably supplied into the processing block. Although this equation is not essential in the present invention, it is assumed that three image signal transformations (encoding, pre-decoder processing and decoding) are performed with the power law function. Equation (7) represents the processing function of block fp and accepts input signals Sa and Se and outputs signal Sp. A new feature of this embodiment is the introduction of a gray level turn-off point denoted by So, leading to three conditional cases expressed in equation (7). The first condition is applicable when the encoded signal level falls below the level derived from So, in which case these signal levels are set to 0 (ie full black). Next, for the encoded signal levels above the level derived from So but below the threshold level derived from St, the second condition of equation (7) is applicable. The third condition in Eq. (7) is applicable to signal levels encoded above St-derived levels. The second condition is used to smooth the transition between the raised black level and the pull off level, creating a sinusoidal ramp on the display drive signal (Sd) between So (drive level = 0) to St (drive level = St). do.

식(7)

Expression (7)

a = signal encoding 멱 exponent (assuming 멱 law encoding)

γ = signal decoding 멱 exponent (assuming 멱 law decoding) So, St, Sb and β are included in the environmental response control signal Sa.

So = desired gray level turn-off point as part of the full scale input signal

St = desired gray level threshold as part of the full scale input signal

Sb = desired black level offset as part of the full scale output signal

β = linearity modifier 멱 exponent (assuming the modification of the exponential law)

The gray level turn-off point (So) and the gray level threshold (St) are 1) an environment-response variable determined through a lookup table or a computational algorithm in a processing block marked "Proc", 2) programming in'Proc' Possible commands are'ports', 3) fixed values pre-programmed in'Proc', or 4) any combination of the above. Alternatively, So and St may be fixed values in the fp processing block.

If the encoding index a and the decoding index γ are known quantities as assumed in equation (7), the final signal linearity exceeding the gray level threshold St is only determined by the value of the linearity modifier index β, where β is previously defined It is equivalent to the end-to-end linear 멱 exponent ε. The encoding index a is typically known based on the source of the image data, and the decoding index γ can be given by the manufacturer of the display or can be determined by testing. Equation (7) provides a specific example of the processing described in this section based on the specific method of signal encoding/decoding, but the general processing is the same as other encoding/decoding methods.

An example of the function of equation (7) is shown in FIG. 16. Here, the encoding process is a single power law transform to exponent a = 0.50 (approximate by ITU-R BT.709-5), and the decoding process is to exponent γ = 2.40 (according to ITU-R BT.1886). It is a single power law transformation. In this example, the requested black level offset is set to 0.1, the requested gray level turn off is set to 0.02, the gray level threshold is set to 0.05, and the linearity modifier index β is set to 1.20. The effective decoding transform is given by the lower curve, the end-to-end signal transform has a desired black level offset of 0.1, a gray level turn off of 0.02, and a gray level threshold of 0.05 and a slightly inclined linearity consistent with ε = 1.20. It is given by the middle curve shown. The linear ramp between (So, 0) and (St, Sb) serves to reduce the aforementioned banding effect.

The lower left corner of FIG. 16 is shown in FIG. 17. This shows a smoother transition of end-to-end signal conversion at St = 0.05 in this case at the gray level threshold.

It is repeated that all examples provided in this section are provided only to illustrate the general principles of the invention and do not limit the scope of the invention. In particular, functions other than the sine function can be used in equation (7) to provide "tangential-matching" of the slope of the curve at the critical point to further improve gray level processing in this region.

Exemplary Example 4

The embodiments described in this section use autonomous black level and linearity using ITU-R BT.709-5 (2002) and Image Decoding: ITU-R BT.1886 (2011), which are very common industry standard image encoding methods. Describe the implementation of mediation. This embodiment also serves to generally describe how the present invention can be applied to any encoded/decoded signal conversion format.

The BT.709 encoding process is described by equation (8). The first condition in Eq. (8) is in the transform function for a small signal (i.e. the darkest gray levels) that may have problems with such low level noise, such as in the case of a pure power-law function. It is intended to prevent an almost infinite slope.

식(8)

Expression (8)

The BT.1886 decoding process is simply a power law transformation as described in equation (9).

식(9)

Expression (9)

Referring again to FIG. 12, the encoded image signal S _e and the environment-response control signal Sa are supplied to the image signal processing block indicated by the pre-decoded image signal fp according to the following equation (10) in an exemplary embodiment. It represents the processing function of the block fp that receives the input signals Sa and Se and outputs the signal Sp. The breakpoint at Ss = 0.018 in the encoding process described by equation (8) leads to two sets of conditional cases as expressed in equation (10). The first set of conditions is applicable when the encoded signal level is less than the value of 0.081 (= 4.5 x 0.018), and derives three sub-conditions 1a-1b depending on the encoded signal level. The condition of the second set of equations (10) leads to three more sub-conditions 2a-2c depending on the encoded signal level for the black level transition parameters So and St when the encoded signal level Se is greater than 0.081. When applicable, the sine function is implemented for the black level transition for conditions lb and 2b in equation (10), but there are many functions that can be used for this purpose.

식(10)

Expression (10)

Also, it may be desirable to automatically change the white balance of the display according to the spectral distribution of the ambient light.

As mentioned above, gamma (indicated by γ) generally refers to the mathematical index of the S function S ^γ that converts the gray level scaling (on a sub-pixel basis) in an image. As taught above, an exemplary embodiment of the system relates to sunset and sunrise times for the position of the display without the need to use actual data from the ambient light sensor, as shown in FIG. 8 or data from the ambient light sensor. The desired gamma γ can be selected for the display according to the data. Taking this concept further into consideration, the following embodiments do not require the use of actual data from ambient light sensors, but various display settings based on artificial ambient light sensor data (AAS data), particularly gamma (γ) or Allows the black level to be selected.

It has been found that anomalies in the display environment often change the ambient light sensor data, allowing the display to significantly change the brightness level even if the surrounding environment has not changed significantly. For example, the ambient light sensor may be located within the shadow, and the rest of the displays may not. This optional shading may be caused by, but not limited to, various obstacles, including light poles, trees, passing vehicles and/or construction equipment. Other anomalies are related to ambient light sensor data, including various changes, such as the response of each different sensor, the response of a sensor to a change in temperature, the change in the position of the optical sensor in each display, and the general surrounding environment of the display over time. Can make variability

In some embodiments, as described above, the system can function without the use of data from an ambient light sensor. However, this generally limits the system's functionality and its benefits, especially power savings, and can sometimes cause rapid changes in display brightness. However, the following embodiments provide a system and method for controlling the brightness of an electronic display by generating artificial ambient light sensor data (AAS).

In one embodiment, generating artificial ambient sensor data includes defining the following parameters:

(1) Night Command-Gamma desired at night.

(2) Weekly Command-The desired gamma during the week.

(3) High Ambient Reading (HA)—Approximate raw data received by the ambient light sensor when experiencing the highest ambient light level in the display environment.

(4) Display location or GPS coordinates for address/city/state.

(5) Sunrise transition period (t ^sr )- The amount of time to transition from reading the night ambient light sensor to reading the daytime ambient light sensor (usually measured in seconds).

(6) Sunset transition period (t ^ss )- The amount of time to transition from the daytime ambient light sensor reading to the nighttime ambient light sensor reading (usually measured in seconds).

In this embodiment, during the sunrise transition period, artificial ambient sensor (AAS) data can be calculated in the following way, where t ⁱ provides the transition time (ie, t ⁱ varies between 0 and t ^sr) ).

AAS for sunrise = (t ⁱ * HA)/t ^sr .

Similarly, the AAS for sunset can be calculated in the following way, where t ⁱ gives the transition time (ie, t ⁱ varies between 0 and t ^ss ).

AAS for sunset = HA-(t ⁱ * HA)/t ^ss .

Once the AAS for the transition period is calculated, the desired backlight level can be determined from any of the ambient light to display settings described above.

18 provides a logic flow diagram for performing an embodiment using AAS technology during sunset/sunrise transition times and night/daytime levels for the rest of the time.

In some embodiments, the sunset transition period and sunrise transition period may be similar or substantially the same. In this case, two transition periods may not be necessary. Instead, one transition period can be used. 19 provides a logic flow diagram for performing an embodiment using AAS technology having only a single transition period while using night/day commands for the remaining time.

In advanced embodiments, the system and method may also use local weather information to further adjust display settings without requiring actual data from ambient light sensors. Local weather information can be obtained from available web APIs or other online weather information that can be accessed at predetermined time intervals (eg, every 15 minutes). The weather factor (WF) is used here.

For weekly or random transition periods: WF = 4 * C ⁱ , where C ⁱ = high percentage representing a clear sky and low percentage representing a large amount of cloud cover. Of course, a higher ratio may indicate more cloud cover and a lower ratio may indicate less cloud cover. Any technique can be used by those skilled in the art.

In the present embodiment, artificial ambient sensor (AAS) data during the sunrise transition period may be calculated in the following manner.

AAS for sunrise = (t ⁱ * (HA*WF))/t ^sr .

The AAS for sunset can be calculated in the following way.

AAS for sunset = (HA*WF)-(t ⁱ * (HA*WF))/t ^ss .

During the day, AAS = HA*WF.

AAS = 0 at night.

Once the AAS for the transition period or day is calculated, the desired display setting can be determined from either the ambient light level versus display setting described above.

20 provides a logical flow chart for performing an improved embodiment using AAS technology during daylight hours as well as sunset/sunrise transition times while considering local weather information.

For example, during the daytime (i.e. not during the transition period or at night) and when it is cloudy and rainy, the relevant calculations are:

Ci = 10% clearness percentage

HA = 500

Weather factor = 4 * 0.10 = 0.40

AAS = 500 * 0.40 = 300

If the local weather conditions are not modified, the weekly value is expected to be 500, which means that different display settings (gamma here) are required. Here we can see significant savings due to the cloudy sky.

In the same example, if there is a display in the middle of a sunrise or sunset transition, the calculated light sensor value and corresponding desired brightness are as follows.

t ^sr = 1800 seconds

t ⁱ = 900 seconds

HA = 500

Weather factor = 4 * 0.10 = 0.40

AAS = (900 * 500 * 0.40)/1800 = 100

In the absence of correction of local conditions, the AAS value is 250.

As preferred embodiments of the invention have been shown and described, those skilled in the art will appreciate that many transformations and modifications can be made that affect the described invention and still fall within the scope of the claimed invention. In addition, many of the elements indicated above can be modified or replaced with other elements that provide the same results and are within the spirit of the claimed invention. Therefore, the invention is intended to be limited as indicated by the scope of the claims.

Claims (42)

An electronic display assembly, the electronic display assembly comprising:
An electronic display;
A backlight positioned behind the electronic display; And
And a display controller electrically connected to the electronic display,
The electronic display is directly illuminated by the backlight located behind the electronic display,
The display controller,
If the current time is between sunset and sunrise, cause the electronic display to operate according to night commands without accepting any input from the ambient light sensor, and
If the current time is between sunrise and sunset, cause the electronic display to operate according to daytime commands without accepting any input from the ambient light sensor,
The night commands include a desired gamma setting for the display during low ambient light conditions,
The weekly commands include the desired gamma setting for the display during high ambient light conditions,
The display controller is also configured to automatically adjust the desired gamma setting,
Wherein gamma represents a mathematical index of the power function S ^{γ that} is adapted to transform the gray level scaling in the displayed image. According to claim 1,
The night commands include a desired black level for the display during low ambient light conditions,
The daytime instructions include a desired black level for the display during high ambient light conditions. delete The method according to claim 1 or 2,
And the display controller determines sunrise time and sunset time for each day. According to claim 4,
And the display controller determines sunrise time and sunset time for each day by calculating a sunrise expression. According to claim 1,
The display controller also:
Determine whether the current time is during the sunset transition period or the sunrise transition period,
If during the sunset transition period, calculate the artificial ambient sensor (AAS) data for the sunset,
If during the sunrise transition period, provide artificial ambient sensor (AAS) data for the sunrise, and
The display is operated based on the AAS data,
The AAS data is a value depending on the time of the day,
The calculation of the AAS data, the electronic display assembly characterized in that it is calculated in consideration of the data approximating the ambient light level for the display environment, the sunrise transition period, and the sunset transition period. According to claim 1,
The display controller also:
Calculate artificial ambient sensor (AAS) data,
Determine a desired gamma setting based on the AAS data, and
The electronic display is driven using the desired gamma setting,
The AAS data is a value depending on the time of the day,
The calculation of the AAS data, the electronic display assembly characterized in that it is calculated in consideration of data approximating the ambient light level for the display environment, sunrise transition period, and sunset transition period. According to claim 1,
The display controller also:
Determine local weather information,
Computing artificial ambient sensor (AAS) data based on the local weather information,
Determine a desired gamma setting based on the AAS data, and
The electronic display is driven using the desired gamma setting,
The AAS data is a value depending on the time of the day,
The calculation of the AAS data, the electronic display assembly characterized in that it is calculated in consideration of data approximating the ambient light level for the display environment, data approximating the amount of cloud cover, sunrise transition period, and sunset transition period. delete delete delete The method of claim 6,
Electronic display assembly, characterized in that the desired gamma setting is determined by comparing the AAS data with a predetermined relationship between ambient light and a value corresponding to gamma. delete The method of claim 6,
And the display controller is further configured to determine a black level offset based on the AAS data. delete delete delete delete delete delete A method for adapting the environment of electronic display characteristics, the method comprising:
Providing an electronic display and a backlight positioned behind the electronic display, wherein the electronic display is directly illuminated by the backlight positioned behind the electronic display;
Determining a sunset time and a sunrise time during the day;
Determining whether the current time is between sunrise and sunset or between sunset and sunrise;
Gamma for the display, without accepting any input from the ambient light sensor, based on daytime commands if the current time is between sunrise and sunset, or based on nighttime commands if the current time is between sunset and sunrise. Selecting automatically; And
And driving the display at the selected gamma.
The night commands include a desired gamma setting for the display during low ambient light conditions,
The weekly commands include the desired gamma setting for the display during high ambient light conditions,
Wherein gamma represents a mathematical index of the power function S ^{γ that} is adapted to transform the gray level scaling in the displayed image. The method of claim 21,
The method also,
Gradually changing gamma for the display when transitioning from night to sunrise; And
And gradually changing gamma for the display when transitioning from daylight to sunset. delete The method of claim 21 or 22,
The step of determining the sunset time and sunrise time during the day is performed by calculating a sunrise equation. The method of claim 21,
The method also,
Selecting a black level offset for the display based on whether the current time is between sunrise and sunset or between sunset and sunrise; And
And driving the display at the selected black level offset. The method of claim 21,
The method also,
Determining whether the current time is during a sunset transition period or a sunrise transition period;
If during a sunset transition period, calculating artificial ambient sensor (AAS) data for the sunset;
If during a sunrise transition period, calculating artificial ambient sensor (AAS) data for the sunrise;
If the current time is during the sunset transition period, selecting a gamma for the display based on the AAS data for the sunset to drive the display at the selected gamma; And
If the current time is during the sunrise transition period, selecting a gamma for the display based on the AAS data for the sunrise, and driving the display at the selected gamma,
The AAS data for the sunset or sunrise is a time-dependent value,
The method of claim 1, wherein the calculation of the AAS data for the sunset or sunrise is calculated in consideration of the data approximating the ambient light level for the display environment, the sunrise transition period, and the sunset transition period. delete The method of claim 21,
The method also,
Determining local weather information;
Calculating artificial ambient sensor (AAS) data based on the local weather information;
Selecting a gamma for the display based on the AAS data and whether the current time is between sunrise and sunset or between sunset and sunrise; And
And driving the display at the selected gamma.
The AAS data is a value depending on the time of the day,
The AAS data is calculated by taking into account the data approximating the ambient light level for the display environment, the data approximating the amount of cloud cover, the sunrise transition period, and the sunset transition period. delete delete delete The method of claim 26,
The step of selecting gamma for the display based on the AAS data for the sunset or sunrise is performed by comparing the AAS data for the sunset or sunrise with a predetermined relationship between ambient light of the environment and a value corresponding to gamma. The method characterized by being. delete The method of claim 26,
The method also,
And determining a black level offset for the display based on AAS data for the sunset or sunrise. delete delete delete delete delete delete According to claim 1,
The electronic display assembly also includes a GPS device in electrical communication with the display controller,
And the display controller is adapted to determine position data for the electronic display through the GPS device in electrical communication with the display controller. The method of claim 21,
The method also,
And determining location data for the display via a GPS device.

Images