Patent Application
20210081071
The present invention relates in general to the field of information handling system displays, and more particularly to an information handling system display having a unibody to improve optics.
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.
Generally, information handling systems present processing output to end users as visual images at a display. Displays come in a variety of sizes and generate visual images with a variety of materials. Typically end users prefer flat panel displays that use liquid crystal or organic light emitting diode (OLED) pixels to generate visual images based upon pixel values provided by an information handling system. These pixels are built into a flat panel as an array typically compliant with a display standard, such as the High Definition (HD) and Ultra High Definition (UHD) display standards. A graphics controller defines an array of pixel values that are transferred to the flat panel display by a cable or wireless interface, such as a DisplayPort or HDMI cable. A timing controller in the display scans the pixel values to the array of pixels to generate the visual image. In addition, flat panel displays often include touch detection to accept touch inputs by an end user at the display surface. For instance, a capacitive touch detection sensor integrates with the flat panel display so that touch positions are detected by a touch controller and reported to an operating system. The operating system supports touch inputs at the display by associating detected touch positions with user interface presentations made at the display.
Generally, end users prefer larger display surfaces for presentation of visual information. A larger display surface can simultaneously present multiple pages of a document or multiple application windows having multiple documents. As display peripherals grow larger in the display area, they also tend to become heavier and more awkward to move. Thus, display peripherals with larger display areas tend to have more heavy duty chassis. Typically, the display itself mounts on a stand with an adjustable bracket so that the end user can view the display from a variety of angles, such as where an end user has multiple displays arranged around a desktop. In some situations, the display may have a forward-leaning or rear leaning orientation to adapt to different end user viewing heights. Many large displays, such as for use as large screen televisions, are mounted on walls, mobile carts or floor stands to provide better support and stability for end users.
As the display viewing area increases, difficulty tends to arise in addressing image viewing interference introduced by the Newton Ring phenomena, which tend to interfere with image presentation at touch enabled displays that include a cover glass. A Newton Ring is a circular dark and light interference pattern created by the reflection of light between two surfaces having a spherical surface relationship that creates different thicknesses of air between the reflecting surfaces. A constructive interference is created where light reflects in phase due to a path length difference of an odd multiple of the light wavelength divided by two. A destructive interference is created where light reflects 180 degrees out of phase due to a path length difference of an even multiple of the light wavelength divided by two. Constructive interference generates a bright fringe circular appearance while destructive interference generates a dark fringe circular appearance. Newton Rings may show up, for instance, where a large touch display panel cell warps toward the inner surface of the cover glass relative to a display when leaned forward.
One way to prevent Newton Rings is to adhere a display cover glass to the display panel surface with an optical bond solution, such as a silicon bonding solution, that eliminates the airgap between a cover glass and display panel surface, although the use of such adhesives tends to increase cost. Another solution is to coat the display glass with an anti-Newton Ring solution, however, the solution can scratch the glass surface if the airgap is too small with respect to the display diagonal size. A more common solution is to space the cover glass away from the display panel surface by a distance sufficient to overcome the Newton Ring phenomena. The distance for any particular display varies based upon display area, however, a gap of four millimeters or more between the display glass and display panel surface is not uncommon. Although such a gap reduces manufacture cost relative to other alternatives, it also increases the thickness of the display and introduces optical effects that impact the end user experience. For instance, the gap introduces a parallax error caused by refraction that makes touch location detection for a displayed user interface more difficult by creating an optical offset from the actual position.
Therefore, a need has arisen for a system and method which holds a display cover glass and display panel surface in a narrow, spaced relationship without contact and without inducing Newton Rings.
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 holding a display cover glass and display panel surface in a spaced relationship that minimizes Newton Ring effects. A display panel and cover glass are held in a spaced relationship by a shared structure so that instances of spherical spaced relationship are minimized or avoided even where the gap between the cover glass and display panel is minimized.
More specifically, an information handling system display presents visual images based upon information provided from an information handling system, such as pixel values communicated from a graphics processor. The display has a display panel that integrates an array of pixels for presenting the visual image and a touch detection sensor, such as an infrared (IR) touch detection sensor. The display panel is held in a spaced relationship relative to a cover glass to provide a gap between the display panel and cover glass that prevents or otherwise minimizes introduction of a spherical relationship associated with generation of Newton Ring effects. For instance, a chassis structure couples to both the cover glass and the display panel in a fixed manner that promotes synchronous movement of the cover glass and display panel in response to vibration so that a spherical spaced relationship between the cover glass and display panel is avoided across the display viewing area. The chassis structure, display panel and cover glass are adhered, such as with adhesive tape and then assembled with a display housing to form a unibody structure. By avoiding relative movement between the display panel and cover glass that is associated with Newton Ring and panel scratch effects, a reduced gap size is supported, such as a gap that is a fraction of the thickness of the cover glass. In one example embodiment, the display panel and cover glass fixedly couple to each other with an adhesive tape by positioning the cover glass on a jig, removing the cover glass, positioning the display panel on the jig relative to the cover glass position, applying the adhesive tape to a chassis structure that holds the display panel, placing the cover glass on the jig at its position, and curing the adhesive tape with the display panel and cover glass coupled to the chassis structure. The display panel, cover glass and chassis structure are then assembled with a display housing to form a robust unibody structure.
The present invention provides a number of important technical advantages. One example of an important technical advantage is that a peripheral display has a cover glass coupled in a unibody frame relationship that maintains a spaced relationship while avoiding spherical spacing associated with generation of Newton Rings at the display. Decreased gap size between the display cover glass and display panel surface reduces parallax errors and the perceived depth illusions sometimes associated with increased gap sizes. A thinner display housing is manufactured with the decreased gap size and encased within a robust extrusion part for a slim final product. The cover glass and display panel surface are retained in a unibody structure to flex in a synchronized manner that reduces the creation of spherical spaced relationships associated with generation of Newton Rings and incidental contact that may result in scratching of the cover glass and/or display panel surface.
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 manages Newton Ring effects with a reduced gap size between a display panel and cover glass by coupling the display panel and cover glass to a chassis structure that promotes synchronous movement of the display panel and cover glass in response to vibration or other forces. 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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Display 30 has a display stand 32 that holds a display assembly 44 in an elevated viewing position, such as by coupling to a bracket 34, such as a VESA standard compliant bracket, which pivots about display stand 32 to adjust the end user viewing angle. A display control board 36 couples to the backside of display assembly 44 to provide communication of pixel values received from display port 26 for presentation at pixels 52. For instance, a timing controller (TCO) 38 receives the pixel values and scans the pixel values to individual pixels to create the visual image. A scalar 40 scales pixel values to different resolutions supported by display 30. An EDID stores display configuration information. A touch controller 56 applies position values of touches detected at a IR touch sensor 58 integrated in display 30 and communicates the touch locations to information handling system 10 as touch inputs. For example, touches are communicated to an embedded controller 54, which manages inputs received from input devices, and then to CPU 14 as inputs to an operating system or application associated with presented visual images.
Visual images are presented by a display panel 50 integrated in display assembly 44 by communication of pixel values to pixels 52. In the example embodiment, pixels 52 are liquid crystal pixels that present colors by filtering light passing through each pixel 52 from a backlight disposed behind display panel 50. In alternative embodiments, pixels 52 may be alternative types, such as organic light emitting diode (OLED) material. Display panel 50 is held in place by an extruded encasement that fits around a cover glass 48 coupled over top of display panel 50. Cover glass 48 provides protection for display panel 50 and integrated IR touch sensor 58 with a gap formed between the inner surface of cover glass 48 and the upper surface of display panel 50. Cover glass 48 is, for example, a treated glass surface to have enhanced hardness and resistance to breakage unless subject to high point impact force, such as Gorilla Glass or Heat Tempered Glass. Within display assembly 44, as is described in greater detail below, a chassis structure is provided to which both cover glass 48 and display panel 50 affix so that a defined gap is maintained between cover glass 48 and display panel 50. By maintaining a constant gap size, Newton Ring effects are suppressed, and the size of the gap may be decreased, resulting in a thinner display assembly 44.
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By affixing cover glass 48 and display panel 50 to chassis structure 60 for synchronous motion and reduced spherical relationships, Newton Ring effects are suppressed. Further, an anti-haze treatment is applied to the inner surface of cover glass 48 that further suppresses reflections associated with Newton Ring effects. The anti-haze treatment can induce scratching at display panel 50 if it contacts cover glass 48, so the synchronized motion provides less risk of scratching when anti-haze treatment is used for a given gap 68 size. An examples of an anti-haze treatment that will work in small gap 68 sizes includes NuShield AG film.
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At step 98, the board assembly cell/open cell is placed on the jig table and is aligned to an open cell position, meaning the position relative to the cover glass so that the support surface of the chassis structure in the open cell aligns with a desired location of the cover glass. Alignment of the open cell on the jig table follows a similar process to the cover glass with a pair of sides pressed against the jig devices to establish the open cell position followed by precise measurement of the open cell with stepper motor movement of the jig devices until extension tips press against each side of the open cell. At step 98, an adhesive tape is place on the open cell support surface to prepare for placement of the cover glass. Other types of adhesives may be used, however, an adhesive tape that is not activated allows movement of the cover glass across the tape without marking the cover glass. Once the position of the open cell is determined by the jig devices, the process continues to step 100 by shifting the jig device to positions determined for alignment of the cover glass. For example, the top and left sides of the jig device are put in a final position based upon a distance of the cover glass edge to the open cell edge, while a small space is allowed on the right and lower sides to provide room to fit the cover glass within the jig devices. At step 102 the cover glass is brought from storage and, at step 104 placed upon the jig table in the cover glass position. Once the cover glass is in position, bonding is accomplished by activation of the adhesive tape, such as with heat or infrared light. After adhesive activation is complete, the process continues to step 106 to lift the bonded cover glass and open cell together with the support baseplate for placement in storage to complete curing of the adhesive. At step 108, the jig table is prepared for assembly of another display by placing another support baseplate on the jig table.
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.
