Patent Abstract:
An information handling system keyboard illuminates with light provided from an organic light-emitting diode (OLED) disposed as one or more films within the keyboard, such as proximate to or on a magnet biasing element used in a low profile keyboard. The OLED is powered with current provided through a keyboard membrane, such as with power connectors exposed on the membrane that have OLED films placed on them.

Full Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates in general to the field of portable information handling systems, and more particularly to an information handling system low height illuminated keyboard. 
     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. 
     Portable information handling systems typically include integrated input/output (I/O) devices and a battery to support operations untethered from peripherals and external power. Smaller portable devices often have a planar housing with one side populated by a touchscreen display so that end users can make inputs and view outputs without using a keyboard. Smartphone and tablet information handling systems are examples of systems that do not include physical keyboards, although smartphone and tablet information handling systems do often support interactions with peripheral keyboards through USB cables or wireless personal area networks (WPANs) such as Bluetooth. An advantage of the planar footprint and lack of a physical keyboard is that the thin height—also known as Z factor—allows users to conveniently store a phone or tablet in a purse or pants pocket. A disadvantage is that the touchscreen display keyboard tends to be difficult to use due to its small size and lack of physical input feedback. Typically end users prefer information handling system devices with physical keyboards when doing tasks that call for extended inputs, such as word processing or email tasks. When using a smartphone or tablet device with a peripheral keyboard, users effectively sacrifice some portability since the peripheral device increases the overall size of what the user must carry. Often, the peripheral keyboards come with a carrying case that holds the smartphone or tablet. 
     End users who tend to perform functions that use more typing, such as word processing, tend to prefer portable information handling systems that have integrated keyboards for more rapid inputs. Generally, portable information handling systems with integrated keyboards have a larger footprint with a clamshell or convertible form factor that provides room for more power processing components than those typically found in tablet systems. On the one hand, the more powerful processing components provide an enriched end user experience that provides support for a greater number of applications to execute. On the other hand, the more powerful processing components tend to use more power and generate more heat so that a larger battery and a cooling fan are generally included. Generally, the selection of the processing components, battery and cooling fan are driven by the size of the display integrated in the portable information handling system. Since the display and main housing tend to have the same X and Y size definitions, larger displays tend to have housings with greater internal space that supports more processing, power and cooling capabilities. End users typically understand that portability and display size are a tradeoff, however, end users who are used to the thin Z height of tablet information handling systems do desire to have clamshell and convertible systems with a reduced Z height if possible. 
     In order to reduce the Z height of information handling systems in general, manufacturers tend to use thin battery packs and tightly constrained motherboard configurations. These considerations help reduce the thickness of the main housing for systems that integrate a keyboard and the thickness of the planar housing of tablet systems. Portable information handling systems that integrate a keyboard tend to have physical constraints that limit size reductions available in Z height due to the room used by keys to travel vertically. End users tend to expect at least some minimal amount of movement, and the guided travel of a key tends to call for at least some structure in the keyboard that adds to Z height. Conventional keyboards tend to use a rubber dome that maintains a desired return pressure for the end user. Where Z height is a concern for end users, structures that have less key movement and different return forces may be used. For example, magnets disposed between keys and a support surface provide key movement with a thinner structure that helps reduce keyboard thickness. One feature sought in portable information handling system keyboards is illumination of the keys. When working in environments that have restricted light, users rely on illumination from behind the keys in order to see which keys are being pressed. LEDs or other light sources used to illuminate behind the keyboard tend to add some height. 
     SUMMARY OF THE INVENTION 
     Therefore a need has arisen for a system and method which provides an information handling system low height keyboard illumination. 
     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 illuminating an information handling system keyboard. Organic light-emitting diode (OLED) film disposed in a keyboard structure and powered from the keyboard membrane illuminates keyboard keys with minimal impact keyboard height. 
     More specifically, an information handling system interfaces with a keyboard to accept key inputs, such as with an integrated keyboard coupled through an internal bus or through a peripheral keyboard interfaced though a cable or wireless network. The keyboard includes plural keys, each key having a key cap supported on a lever structure that bias the key upwards away from a bottom support surface. In one embodiment, a magnet located under each key pulls a metal portion of the lever structure downward to bias the key upwards. A membrane disposed over the bottom support surface detects key inputs and sends a signal corresponding to key inputs from the key location to the information handling system. The membrane includes power wirelines to each key of the keyboard to selectively power an OLED film that provides backlight for the keys. The OLED film is deposited directly on the membrane, on the lever structure, on the magnet, on the bottom support and/or on the key cap with power routed to the OLED film from the membrane through the keyboard structure as necessary. Clear portions of the keyboard structure aid transmission of the light to the key cap. 
     The present invention provides a number of important technical advantages. One example of an important technical advantage is that keyboard illumination is provided with minimal impact on the height of the keyboard. OLED devices are integrated in the flexible printed circuit board used as the keyboard membrane so that additional structures to support keyboard illumination that would add height are minimized or avoided. Improved illumination is more precisely guided to the keys with light guiding structures integrated in the mechanical structure for each key. More precise illumination reduces power consumption from generation of excess non-directed light and provides a more pleasing user experience with the keyboard keys more precisely illuminated so that less spill over illumination decreases the contrast of the keys relative to ambient light and throws off ambient light correction of a display disposed over or otherwise proximate the keyboard. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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. 
         FIG. 1  depicts a blown up view of a portable information handling system having a keyboard illumination with an OLED film; 
         FIG. 2  depicts a side perspective cutaway view of a keyboard having a low Z height with actuation supported by a magnet; 
         FIG. 3  depicts an upper perspective view of actuation of a keyboard input to provide an input signal; 
         FIG. 4  depicts a side cutaway view of a keyboard key configured to provide key illumination with an integrated OLED light source; 
         FIG. 5  depicts an upper perspective view of a membrane having an OLED film disposed proximate a key for illumination; 
         FIG. 6  depicts a side cutaway view of a key having OLED illumination provided through a transparent lever arm; 
         FIG. 7  depicts an upper view of an OLED film disposed on a keyboard support and powered from the keyboard membrane; 
         FIG. 8  depicts a side perspective view of an OLED film disposed on keyboard support that illuminates a key; and 
         FIG. 9  depicts a side cutaway view of a keyboard having a rubber dome return device that integrates OLED key illumination. 
     
    
    
     DETAILED DESCRIPTION 
     OLED film disposed within an information handling system keyboard structure provides back light to illuminate keys with power provided for the film through the keyboard membrane. 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. 
     Referring now to  FIG. 1 , a blown up view depicts a portable information handling system  10  having a keyboard illumination with an OLED film. Portable information handling system  10  has a main chassis  12  that supports a motherboard  14  and processing components that process information, such as a central processing unit (CPU)  16 , random access memory (RAM)  18 , hard disk drive (HDD)  20  and keyboard controller  22 . Main chassis  12  couples to a lid  24  that supports a display  26  for presenting information provided from the processing components as visual information. A keyboard cable  28  interfaces the processing components with a keyboard  30  that installs over main chassis  12  to cover motherboard  14 . For example, inputs made at keyboard  30  are communicated through keyboard cable  28  to keyboard controller  22  for use by CPU  16 . In the depicted example embodiment, lid  24  rotates about main chassis  12  between open and closed positions; in alternative embodiments, lid  24  may have a tablet with processing components disposed in it instead of in main chassis  12 , or other types of configurations in which a tablet removeably couples to a keyboard or interfaces with a keyboard through a peripheral cable or wireless interface. 
     Keyboard  30  is depicted in an exploded view to illustrated the various locations within the keyboard structure where key backlight illumination may be added with OLED material  43 , such as an OLED film that is selectively powered with current provided through keyboard cable  28  under the control of keyboard controller  22 . Keys  34  extend out of an upper surface  36  to provide a user with selectable inputs to based upon the characters associated with the keys, such as a QWERTY keyboard that provides ASCI binary code inputs to keyboard controller  22 . A membrane  38  disposed beneath keys  34  detect key inputs and generate a signal unique to each key for communication to keyboard cable  28 . Membrane  38  is, for example, a flexible printed circuit board with wirelines that feed to cable  28  so that key inputs may be uniquely identified. Lever structures  40  are disposed below keys  34  to bias keys  34  in an upwards direction. End users make inputs by pressing on keys  34  to overcome the bias of lever structures  40  and impact membrane  38 . A bottom support structure  42  provides support to maintain keys  34 , membrane  38  and lever structures  40  in relative positions. 
     Those of skill in the art will appreciate that keyboard  30  may have a variety of structures for placement of keys  34  as individual caps or assembled as one part, for membrane  38  and for lever structures  40  to bias keys  34 , such as springs or other types of devices that act to bias keys  34  upwards and away from membrane  38 . In some example embodiments, keyboards include capacitive touch or other types of inputs that detect key presses with or without physical movement of keys  34 . The example embodiment of  FIG. 1  is provided to depict that OLED material  43  may be disposed at various locations of keyboard  30 &#39;s structure in order to obtain desired illumination at keys  34 . For example, OLED material is deposited as a film directly on electrical contacts of membrane  38  so that keyboard controller  22  may selectively illuminate the OLED material  43  by applying current. Alternatively, OLED material  43  is provided on bottom support surface  42 , lever structures  40  and/or keys  34  with current routed to the OLED material from membrane  38  through the keyboard structure. 
     Referring now to  FIG. 2 , a side perspective cutaway view depicts a keyboard  30  having a low Z height with actuation supported by a magnet  44 . A key cap  46  rests in an opening of an upper surface with room to move vertically in response to a press by an end user. Lever structure  40  has a metal center portion pulled downward by magnet  44  so the lever arms bias up key cap  46 . When key cap  46  presses downward, the metal central portion of lever structure  40  is leverage upwards by the lever structure  40  arms and an input is translated to the membrane adjacent magnet  44 . 
     Referring now to  FIG. 3 , an upper perspective view depicts actuation of a keyboard input to provide an input signal. Top membrane portion  48  is pressed downward in response to the key press through a hole layer  50  to press against a bottom membrane layer  52 . Contact between top membrane layer  48  and bottom membrane layer  52  closes a circuit as depicted so that current flows to the keyboard controller to indicate an input. The present invention provides power to illuminate OLED films deposited on the top layer, bottom layer or in the hole layer by selectively providing current flow between the top and bottom layers that passes through the OLED film. For example, a FET or MUX closes the circuit based upon a command from the keyboard controller so that current flow is established. 
     Referring now to  FIG. 4 , a side cutaway view depicts a keyboard key configured to provide key illumination with an integrated OLED light source. Magnet support material  56  supports magnet  44  in hole layer  50  underneath a metal lever arm  62 . Magnet  44  pulls down on metal lever arm  62  to leverage clear polycarbonate arms  60  upwards so that key cap  46  is biased upwards. On a downward push against key cap  46 , clear arms  60  press down on membrane  38  backed by a metal plate  58  to generate an input signal. OLED films may be deposited at various locations within the keyboard structure to generate light in a desired manner. For example, an OLED film deposited directly on membrane  38  receives power for illumination from wirelines exposed on membrane  38  that have current selectively enabled under the management of the keyboard controller. Illumination to key cap  46  is guided through transparent material of polycarbonate arm  60 . Alternatively, OLED film is deposited on lever structure  40 , the underside of key cap  46 , metal plate  58  and/or magnet  44 . Current to illuminate the OLED film is forwarded to the deposited films from membrane  38  through the keyboard structure as necessary. 
     Referring now to  FIG. 5 , an upper perspective view depicts a membrane  38  having an OLED film  43  disposed proximate a key for illumination. OLED film  43  is deposited directly onto membrane  38  and over exposed wirelines so that current is provided from membrane  38  through OLED material  43  when turned on by the keyboard controller. In the depicted embodiment, membrane  38  has material added in locations where light illumination is desired. OLED film  43  adds minimal thickness and power consumption to membrane  38  so that key backlight illumination is provided without increasing keyboard height. 
     Referring now to  FIG. 6 , a side cutaway view depicts a key having OLED illumination provided through a transparent lever arm  60 . Power applied from membrane  38  causes illumination upwards along light path  64  through lever arm  60  and towards key cap  46 . In the example embodiment, illumination is provided from opposing sides of the key structure for more even key illumination. Key cap  46  may have a transparent or translucent material to pass light, or may have the character represented by the key left transparent for improved clarity by an end user. In one embodiment, OLED material is deposited on the bottom of key cap  46  to illuminate a character formed by transparent material or printed with the OLED material. Current to illuminate the OLED material is provided from membrane  38  and routed through wirelines embedded in key cap  46  or other conductive material printed over the bottom surface of key cap  46  to establish an electrical contact with membrane  38 . 
     Referring now to  FIG. 7 , an upper view depicts an OLED film  43  disposed on a keyboard support  58  and powered from the keyboard membrane  38 . In the example embodiment, OLED material is provided on both keyboard support  58  and magnet support  56  in the membrane  30  opening so that illumination is provided through the central portion of key cap  46 . Placing the OLED material on the support surfaces provides an additional avenue for providing power to illuminate the OLED material instead of through membrane  38 . For instance power wirelines may be routed on or under the supporting surfaces. OLED material is placed to provide a general and more even illumination that flows upwards towards key cap  46 . In one embodiment, the amount of illumination is varied by changing the current provided to the OLED material or by changing which portions of OLED material is powered. In another embodiment, brightness is set by the thickness of OLED material. In the example embodiment of  FIG. 7 , illumination is provided with OLED film deposited beneath magnet  44 . 
     Referring now to  FIG. 8 , a side perspective view depicts an OLED film  43  disposed on keyboard support that illuminates a key. As illustrated by light path  64 , illumination passes through clear arms  60  upwards to key cap  46 . In the example embodiment of  FIG. 8 , OLED material is deposited on magnet  44  and passed through openings in the metal portion of lever structure  40 . The placement of OLED films may vary based upon the available light paths to key cap  46 , the ease of depositing the OLED film, and the availability of power for illumination of the OLED film. 
     Referring now to  FIG. 9 , a side cutaway view depicts a keyboard having a rubber dome  64  return device that integrates OLED  43  key illumination. Conventional keyboards dispose a rubber dome  66  within a lever structure  40  to bias key cap  46  upwards. Although the magnet based keyboards described above offer a lower Z height than is typically available in a rubber dome  66 , rubber dome  66  tends to provide users with a more natural feedback of a key input. As is depicted in  FIG. 9 , rubber dome  66  has OLED films  43  integrated within it to provide illumination at key  46 . For example, an OLED film and wire interface is injection molded within rubber dome  64  and interfaced with membrane  38  to obtain current for illumination. Alternatively, OLED film  43  is placed on top of the surface of rubber dome  66  with wirelines or other electrical contacts to a current source of membrane  38 . In one embodiment, electrical contacts exposed in rubber dome  66  obtain current from electrical contacts exposed in membrane  38 . Embedded OLED film  43  is placed in locations of rubber dome  66  that have reduced or minimal flexure, such as at the top portion that contacts cap  46  or the base that remains erect during key inputs. In alternative embodiments, OLED films  43  may be placed in other areas of the key structure as set forth above. 
     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.

Technology Classification (CPC): 7