1. Field of the Invention
The present invention relates in general to the field of information handling system display devices, and more particularly to an information handling system display viewing angle compensation.
2. Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems generate information for presentation at a display, such as documents generated by a word processing application, drawings generated by CAD or other drawing applications, pictures generated from compressed JPG files and movies generated from compressed MPEG files. Often, visual information is available for presentation with relatively high resolutions, such high definition movies presented from a Blu-Ray Disc player. End users tend to enjoy a better experience when high resolution visual images are presented at displays that have a generally larger viewing area. As the cost of liquid crystal displays (LCD) has decreased over time, many users have migrated towards the use of larger displays for use with information handling systems. For instance, 24 inch LCDs have become common in the work place. End users often find that a larger display benefits work efficiency by allowing simultaneous viewing of multiple documents and deeper inspection into high resolution images. In response, display manufacturers have provided displays to the marketplace with greater size, such as 27 inches or greater, and increased aspect ratios, such as 16:9 or 21:9 ratios of length versus height.
Display manufacturers will typically calibrate displays before shipment to retailers or end users. The displays are tested to ensure that overall screen provide an adequate color, contrast and brightness response. Imperfections introduced due manufacturing process limitations, such as cell gap differences, will cause an LCD panel to exhibit some color or brightness differences across a screen viewing area. A difficulty for calibration introduced by the use of relatively large display screens is that the viewing angle of an end user to a display can vary significantly across the viewing area of a display, especially with displays that have a wide aspect ratio. Even where individual pixels have uniform brightness or color, different viewing angles across the width and height of a display will cause an end user to experience some form of color and brightness differences at different sections of the display. The impact of viewing angle becomes apparent when displaying a full white screen at different viewing angles. Thus, even if an LCD screen has uniform color, brightness and contrast across all pixels, an end user will experience a less than optimal presentation of images. The end user experience will further suffer if the end user is himself off-center the display since viewing angles will increase for the more distal portions of the display.
Therefore a need has arisen for a system and method which supports presentation of information at a display with compensation for an end user's viewing angle.
In accordance with the present invention, a system and method are provided which substantially reduce the disadvantages and problems associated with previous methods and systems for presenting information as visual images at a display. Visual information provided to a display is compensated based upon a view angle of an end user viewing the display to provide the end user with a uniform visual image. View angle compensation adjusts the presentation of the visual image to offset the effects of end user viewing angle on light distribution from the display.
More specifically, an information handling system processes information to provide visual information to a display, such as pixel values for presentation at a display. A viewing angle compensator, such a firmware instructions executing on a scaler processor of the display, compensates pixel values to correct for viewing angles associated with the pixels. For instance, pixels viewed from a greater angle are presented with increased brightness to provide a uniform appearance relative to pixels viewed from a lesser angle. View angle compensation values are stored in a compensation table of the display. Viewing angle compensation is applied for an expected end user position relative to the display. Alternatively, in one embodiment, an actual viewing position is determined by analyzing a camera image to determine the location of an end user relative to the display. In another embodiment, viewing angle compensation is further enhanced with adjustments to backlight LEDs across the display.
The present invention provides a number of important technical advantages. One example of an important technical advantage is that an end user experiences a more uniform presentation of visual images at a display. The display compensates for viewing angles that an end user experiences when viewing images so that the image appears uniform to the end user even though the presentation of the image by individual pixels is intentionally non-uniform. For example, a display is calibrated to have brightness and color variations for the anticipated viewing angles of an end user by estimating the distance from the screen at which an end user will view images and applying the estimated distance to the height and width of the screen. A typical adjustment will have a gradual increase in brightness for pixels as the distance of the pixels increases from the center of the viewing area. In one embodiment, the actual viewing angle experienced by an end user is determined from observations with a camera integrated in the display so that viewing angle compensation adjusts to an end user's position, even where the position is off-center.
The present invention may be better understood, and its numerous objects, features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. The use of the same reference number throughout the several figures designates a like or similar element.
An information handling system display presents visual images having compensation for the angle of viewing at locations across the display relative to a viewing location. For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, or other purposes, For example, an information handling system may be a personal computer, a network storage device, or any other suitable device and may vary in size, shape, performance, functionality, and price, The information handling system may include random access memory (RAM), one or more processing resources such as a central processing unit (CPU) or hardware or software control logic, ROM, and/or other types of nonvolatile memory. Additional components of the information handling system may include one or more disk drives, one or more network ports for communicating with external devices as well as various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components.
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Pixel values from graphics subsystem 24 are provided to display 12 at a port 26 for further processing by a scaler processor 28 and for application by a timing controller 30 as pixel control signals to pixels 32. Visual images are generated at display 12 by passing light from a backlight 34, such as an array of LEDs 36, through a matrix of pixels 38 and out a clear or translucent cover 40. Pixel values applied by timing controller 30 adjust the form of liquid crystals at each pixel 38 to alter the color, contrast and brightness of light passing from backlight 34 through pixels 38 and out of cover 40. The example embodiment of
Display 12 presents visual images with brightness, color and contrast at pixels 38 generated from pixel values provided by graphics subsystem 24, however, the actual brightness, color and contrast of the visual image experienced by the end user depends upon the angle at which the end user views the pixels. In order to provide the end user with a uniform appearance for a visual image, a viewing angle compensator 42 running on a processor of display 12, such as scaler processor 28, adjusts pixel values to make the actual image non-uniform so that the visual image experienced by an end user appears uniform to the end user. For instance, an end user viewing the same pixel value at all pixels 38 from a viewing point centered in front of display 12 will see a visual image having less brightness, color and contrast at the edges of display 12. Viewing angle compensator 42 references a compensation table 44 to apply compensation values and algorithms that increase brightness, color and contrast for pixel values of pixels at the edge of display 12 so that the end user sees a visual image having a uniform appearance. In one embodiment, in addition to performing compensation by adjusting pixel values, viewing angle compensator 42 compensates brightness by adjusting LEDs 36 to provide greater brightness at greater viewing angles. LEDs 36 may be adjusted individually or in groups based upon their position in display 12.
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Although the present invention has been described in detail, it should be understood that various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention as defined by the appended claims.