Patent Publication Number: US-10332702-B2

Title: Using organic light emitting diode (OLED) film to illuminate keycaps of keys in a keyboard

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present patent application is a continuation of U.S. patent application Ser. No. 15/583,048 filed on May 1, 2017 entitled “Using Organic Light Emitting Diode (OLED) Film to Illuminate Keycaps of Keys in a Keyboard” and is incorporated by reference herein in its entirety and for all purposes as if completely and fully set forth herein. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates generally to computing devices having a keyboard and, more particularly, to using an organic light emitting diode (OLED) panel in each key to illuminate each keycap. 
     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. 
     A computer keyboard (e.g., QWERTY-based or similar keyboard) may be used to provide input to a computing device. For example, a keyboard may be integrated into a computing device, such as a laptop, tablet, phone, or other portable computing device. As another example, a standalone keyboard may be used to provide input to a desktop computing device, a tablet computing device, or other computing device that does not include an integrated computing device. Many keyboards provide illuminated keyboards to enable users to view the keys in poorly lit environments. However, achieving relatively uniform illumination of each keycap of the keyboard may be challenging for a variety of reasons. 
     SUMMARY OF THE INVENTION 
     This Summary provides a simplified form of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features and should therefore not be used for determining or limiting the scope of the claimed subject matter. 
     In some examples, a housing may include a keyboard having a plurality of keys. An individual key of the plurality of keys may include a keycap, an organic light emitting diode (OLED) film (or sheet), a key mechanism, and a base. When power is provided to contacts on the base of the individual key, the power may travel across conductive traces (or wires) in the key mechanism to pads on the OLED film, causing the OLED film to emit light. The light from the OLED film may illuminate a character or symbol embedded into the keycap or the OLED film may be shaped into the character or the symbol and embedded into the keycap. The housing may be (i) separate from and communicatively coupled to a second housing that includes one or more processors or (ii) physically attached to a display device as part of a laptop device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present disclosure may be obtained by reference to the following Detailed Description when taken in conjunction with the accompanying Drawings. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same reference numbers in different figures indicate similar or identical items. 
         FIG. 1  is a block diagram of an architecture of a computing device that includes an illuminated keyboard according to some embodiments. 
         FIG. 2  is a first block diagram illustrating an OLED sheet in a key of a keyboard to illuminate a keycap of the key according to some embodiments. 
         FIG. 3  is a second block diagram illustrating an OLED sheet in a key of a keyboard to illuminate a keycap of the key according to some embodiments. 
         FIG. 4A  illustrates a scissor mechanism before a key is pressed, according to some embodiments.  FIG. 4B  illustrates the scissor mechanism after the key is pressed, according to some embodiments. 
         FIG. 5  is a block diagram illustrating an OLED sheet according to some embodiments. 
         FIG. 6  is a block diagram illustrating layers of an OLED stack according to some embodiments. 
         FIG. 7  illustrates an example configuration of a computing device that can be used to implement the systems and techniques described herein. 
         FIG. 8A  illustrates two OLED sheets under a keycap of a key according to some embodiments.  FIG. 8B  illustrates illuminating a first of the two OLED sheets according to some embodiments.  FIG. 8C  illustrates illuminating a second of the two OLED sheets according to some embodiments.  FIG. 8D  illustrates components of the keycap. 
     
    
    
     DETAILED DESCRIPTION 
     For purposes of this disclosure, an information handling system may include any instrumentality or aggregate of instrumentalities operable to compute, calculate, determine, classify, process, transmit, receive, retrieve, originate, switch, store, display, communicate, 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 (e.g., desktop or laptop), tablet computer, mobile device (e.g., personal digital assistant (PDA) or smart phone), server (e.g., blade server or rack server), 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, touchscreen and/or video display. The information handling system may also include one or more buses operable to transmit communications between the various hardware components. 
     The systems and techniques described herein may use an organic light emitting diode (OLED) panel in each key of a keyboard to provide illumination (e.g., light) under the keycap of each key. Each key may include a scissor mechanism to hold the keycap above a base plate and a dome (e.g., rubber or metal dome) within the scissor mechanism. When the user applies more than a predetermined amount of pressure to the keycap, the scissor mechanism may decrease in height and contact the base plate, causing a key press associated with that particular key to be registered. The OLED sheet (or film) may be placed below the keycap (e.g., above the scissor mechanism). To provide power to the OLED sheet (or film) in each key, metal traces may be placed on the outside (or inside) of the dome. Power applied on a base of each key may travel up the metal traces on the dome to provide power to the OLED sheet (or film) below each keycap of each key. 
     The keyboard may be housed in a keyboard housing. In a desktop computing device, the keyboard housing may be separate from a second housing used to house a computer motherboard, a display device, other computer component, or any combination thereof. In a laptop computing device, the keyboard housing may be attached (e.g., by hinges or another mechanism) to a second housing used to house the computer motherboard, a display device, other computer component, or any combination thereof. To illuminate a keycap of individual keys, an OLED sheet (or film) may be placed in each key, e.g., just below each keycap. 
     In contrast, in a conventional lighted keyboard, a light source (e.g., a strip of LEDs) may be placed at one end of the keyboard housing to shoot light horizontally across the bottom of the keyboard housing, with diffraction elements in the keyboard housing used to reflect light up (e.g., vertically) towards the keycaps. Thus, in a conventional lighted keyboard, light may travel horizontally, be reflected vertically and, for each key, pass through the base plate, the scissor mechanism, the dome, to illuminate a bottom of the keycap. The lighting mechanism in a conventional lighted keyboard is therefore inefficient because such a mechanism results in significant light loss. Inefficient lighting means a conventional lighted keyboard consumes more power. Furthermore, because the light source is at one end of the keyboard housing, light is not uniformly distributed among the keycaps. 
     By using relatively small (e.g., at least approximately 1 centimeter (cm) by 1 cm) OLED sheets underneath each keycap of a keyboard, several benefits are realized. First, because light is provided where needed, with little or no light loss, OLED sheets are much more efficient as compared to a conventional lighted keyboard. Second, because there is very little light loss, lighting the keycaps using OLED sheets consumes less power (e.g., resulting in improved battery life for laptops). For example, a conventional illuminated keyboard may consume one watt of power while a keyboard using OLED sheets to light the keycaps may use at least 50% less power as compared to a conventional illuminated keyboard. Third, the keyboard may be made smaller in height because the light source and diffraction elements are not needed and therefore are removed from the keyboard housing. Typically, the primary factor limiting how thin a laptop can be manufactured is the depth of the keyboard. Using OLED sheets enables the height of the keyboard to be reduced, thereby reducing the thickness of portable computing devices such as laptops. Fourth, each keycap may receive approximately the same amount of light, improving uniformity and reducing (or eliminating) hotspots. Thus, using OLED sheets may result in less significantly light loss, significantly (e.g., at least 50%) less energy consumption, more uniformly lit keys, and a thinner keyboard. 
     In a first example, a computing device may include a first housing to house a first set of components and a second housing to house a second set of components. For example, the second set of components may include a keyboard having a plurality of keys. Each key of the plurality of keys may include a corresponding keycap, OLED sheet (or film), key mechanism (e.g., dome), and base. The OLED sheet (or film) may include a first pad and a second pad to receive power. A first and second conductive trace may run from a top of the key mechanism (e.g., dome) to a bottom of the key mechanism. The first and second electrical contacts on the base may touch the first and second conductive traces, respectively. When power (e.g., from a power source) is applied to the first and second electrical contacts on the base, the power flows across the first and second conductive traces to the first and second pad of the OLED sheet (or film), causing the OLED sheet (or film) to emit light. The OLED sheet (or film) may be 0.2 millimeters or less in thickness, and about 1 cm (length) by about 1 cm (width). In some cases, the OLED sheet (or film) may be shaped like a character or a symbol and embedded into the keycap. In other cases, a character or a symbol may be embedded into the keycap using a material (e.g., plastic, glass, or other transparent or translucent material) through which light from the OLED sheet (or film) passes. 
     In a second example, a computing device may include a first housing with a first set of components and a second housing with a second set of components. For example, the second set of components may include a keyboard having a plurality of keys. Each individual key of the keyboard may include an OLED sheet (or film) below each corresponding keycap. Applying power to the OLED sheet (or film) causes the OLED sheet (or film) to emit light. When the computing device is a laptop device, the first housing is connected to the second housing by one or more hinges. When the computing device is a 2-in-1 device, an attachment mechanism enables the first housing to be connected to the second housing for use as a laptop device and enables the first housing to be detached from the second housing to enable the first housing to be used as a tablet computing device. When the computing device is a desktop device, the first housing is separate from the second housing. Applying power from a power source to electrical contacts on a base of each individual key may cause the power to flow across conductive traces on at least a portion of a key mechanism (e.g., dome, scissor, or other mechanism) to electrical pads on the OLED sheet (or film), causing the OLED sheet (or film) to emit light. In some cases, the OLED sheet (or film) may have a shape of a character or a symbol found on a computer keyboard and may be embedded into the keycap. In other cases, the keycap may have embedded material in the shape of a character or symbol. The embedded material may transmit the light emitted by the OLED sheet (or film). The OLED sheet (or film) may include an emissive layer of organic material between a cathode and an anode. 
     In a third example, a computing device may include a first housing with a first set of components and a second housing with a second set of components. The second set of components may include a keyboard having a plurality of keys. An individual key of the keyboard may include (i) a keycap, (ii) an embedded character or symbol in the keycap, an OLED sheet (or film), and a base. The computing device may have an associated power supply to provide power to the base of each individual key of the keyboard. Applying power to the base of an individual key causes the power to travel from the base, through a key mechanism, to the OLED sheet (or film). For example, the power may travel from the base to the OLED sheet (or film) via conductive traces placed in or on the key mechanism (e.g., dome) of the individual key. An individual key of the keyboard may include at least one of a scissor mechanism or a dome (e.g., made of metal or rubber). In some cases, the OLED sheet (or film) may be embedded in the keycap in the form of a character or a symbol. In other cases, an embedded symbol made of a material that transmits light (e.g., emitted by the OLED) may be embedded into the keycap. 
       FIG. 1  is a block diagram of an architecture  100  of a computing device  102  that includes an illuminated keyboard  104  according to some embodiments. The computing device  102  may include two housings, such as a first housing  106  and a second housing  108 . The first housing  106  may house a display device. The second housing  108  may house the keyboard  104 . When the computing device  102  comprises a laptop device, the first housing  106  may be connected to the second housing  108  by a mechanism  110  (e.g., one or more hinges). When the computing device  102  comprises a 2-in-1 device, the mechanism  110  may enable (i) the first housing  106  to be temporarily connected to the second housing  108  for use as a laptop device and (ii) the first housing  106  to be detached from the second housing  108  to enable the first housing  106  to be used as a tablet computing device. When the computing device  102  comprises a desktop device, the first housing  106  may be separate from the second housing  108  (e.g., the mechanism  118  may not be present). The keyboard  104  may include alphanumeric characters and symbols from one or more languages. 
     To illuminate the keys of the keyboard  104 , each key  112  of the keyboard  104  may include an organic light emitting diode (OLED) panel  114 . For example, the keyboard  104  may include N keys, e.g., keys  112 ( 1 ) to  112 (N) (N&gt;0, typically N&gt;80). Each of the keys  112 ( 1 ) to  112 (N) may include a corresponding OLED sheet  114 ( 1 ) to  114 (N). Of course, the keyboard  104  may include a means, such as a switch, to turn on the OLED sheets  114 ( 1 ) to  114 (N) when the user desires that the keys of the keyboard  104  be illuminated and to turn off the OLED sheets  114 ( 1 ) to  114 (N) when the user desires that they keys  112  of the keyboard  104  not be illuminated. The second housing  108  may include additional input devices, such as a touchpad  116 . 
     Thus, multiple OLED sheets may be located under those keycaps in a keyboard that are to be illuminated. By using relatively small (e.g., at least approximately 1 centimeter (cm) by 1 cm) OLED sheets underneath each keycap of a keyboard, several benefits are realized. Light is provided where needed, with little or no light loss. Lighting the keycaps using OLED sheets may consume less power (e.g., resulting in improved battery life for laptops) because there is very little light loss. For example, a keyboard using OLED sheets to light the keycaps may use at least 50% less power as compared to a conventional illuminated keyboard. The keyboard housing may be made thinner (e.g., smaller in height) because the light source and diffraction elements used in a conventional illuminated keyboard are not used and may therefore be removed from the keyboard housing. Reducing the height of the keyboard may reduce the thickness of portable computing devices, such as laptops and 2-in-1 computing devices. Using an OLED sheet under individual keycaps of the keyboard provides more uniform lighting of keys, thereby reducing (or eliminating) hotspots. Thus, using OLED sheets to illuminate keycaps of keys in a keyboard may result in less significantly light loss, significantly (e.g., at least 50%) less energy consumption, more uniformly lit keys, and a thinner keyboard. 
       FIG. 2  is a first block diagram illustrating an OLED sheet in a key  200  of a keyboard to illuminate a keycap of the key according to some embodiments. For example, the key  200  may be a representative one of the keys  112 ( 1 ) to  112 (N) of  FIG. 1 . 
     The key  200  includes a keycap  202 . An OLED sheet  204  is positioned below the keycap  202 . The OLED sheet  204  may be a printed OLED sheet that is inserted between the keycap  202  and a key mechanism, such as the representative key mechanism illustrated in  FIG. 2 . While  FIG. 2  illustrates a dome-type key mechanism, the OLED sheet  204  may be inserted below the keycaps of other types of key mechanisms. The OLED sheet  204  may be thin (e.g., &lt;0.2 millimeters (mm)) and approximately 1 centimeter (cm)×1 cm for regular keys and approximately 1 cm×1.5 cm for larger keys (e.g., ENTER key, SHIFT key, and the like). The term approximate means that the keys may be up to 20% larger or up to 20% smaller than 1×1 cm or 1×1.5 cm. The OLED sheet  204  does not interfere with the operation of the key mechanism. The shape of the OLED sheet  204  may be optimized for each keycap of the keyboard. The OLED sheet  204  may include two contact pads  206 ( 1 ) and  206 ( 2 ) to provide power to an anode and a cathode of the OLED. For example, as illustrated in  FIG. 2 , the two contact pads  206 ( 1 ) and  206 ( 2 ) may be located on the bottom of the OLED sheet  204 . 
     The representative key mechanism  200  may include a dome  208  made of a material such as rubber, metal, plastic, another material, or any combination thereof. While a dome-switch key mechanism is illustrated in  FIG. 2 , the OLED sheet  204  may be used under the keycap  202  of any other type of key mechanism, such as a spring-based key mechanism (e.g., Cherry MX, Romer-G, or the like), capacitive, scissor-switch (also illustrated in  FIG. 2 ), mechanical-switch, buckling-spring, hall-effect, optical, laser, or the like. Electrical traces  210  (e.g.,  210 ( 1 ) for the anode and  210 ( 2 ) for the cathode) may be injection molded in or printed on the dome  208  to carry power to the OLED sheet  204 . The electrical traces  210  may be located outside the dome  208 , inside the dome  208 , or partly outside and partly inside. 
     The dome  208  may run through a hole in a scissor mechanism  212 . The scissor mechanism  212  and/or the dome  208  may hold the keycap  202  above a base  214 . The scissor mechanism  212  may include two pieces that are capable of rotating along a hinge relative to each other, similar to a pair of scissors. When a user applies pressure to the keycap  202 , (i) the arms of the scissor mechanism  212  may rotate, causing the keycap  202  to decrease the distance between the dome  208  and the base  214 , and/or (ii) the dome  208  may compress, causing the keycap  202  to decrease the distance between the dome  208  and the base  214 . When the distance between the dome  208  and the base  214  is less than a predetermined amount, the keyboard may register a keypress of the key  200 . 
     The base  214  may include two contacts  216 ( 1 ) and  216 ( 2 ) where power (e.g., direct current (DC)) is applied. The power may travel from the contacts  216 , along the traces  210 , to the pads  206  of the OLED sheet  204 . One of the contacts  216  may connect to a cathode of the OLED sheet  204  and another of the contacts  216  may connect to an anode of the OLED sheet  204 . 
     The keycap  202  may include an illustration  218 , such as an alphanumeric character or a symbol, that is embedded into the keycap  202 . For example, in some cases, the keycap  202  may be made of a material (e.g., plastic, glass, or the like) that is dark and relatively opaque (e.g., little or no light pass through). In this example, the illustration  218  embedded into the keycap  202  may be made of a material that enables at least a portion of the light from the OLED sheet  204  to be transmitted, enabling a user to discern the illustration  218  in a dimly lit environment. The illustration  218  embedded into the keycap  202  may be made of a transparent or a translucent material (e.g., plastic, glass, or the like). The shape of the OLED sheet  204  may be optimized for each keycap of the keyboard. For example, if the illustration  218  occupies a relatively small amount of the top area of the keycap  202 , the OLED sheet  204  may be shaped accordingly. To illustrate, a narrow rectangular shape may be used for the OLED sheet  204  under illustrations such as the character “I”, the number “1”, the symbol “!”, and the like. A semi-circular shape may be used for the OLED sheet  204  under illustrations such as the character “C”, the parenthetical symbol “(”, and the like. In some cases, the illustration  218  may comprise the OLED sheet  204 . For example, the OLED sheet  204  may be embedded into the keycap  202  in the shape of the illustration  218  and may include the electrical pads  206 . Thus, in some cases, the illustration  218  may be made from a material that transmits the light emitted by the OLED sheet  204  while in other cases, the illustration  218  may be made using the OLED sheet  204  that has been shaped in the form of a character or a symbol. Some keyboards may use a combination, e.g., a portion of the keys may use OLED material embedded into the keycap  202  in the form of the illustration  218 , and a remainder of the keys may use the OLED sheet  204  under the keycap while the illustration  218  that is embedded into the keycap  202  may be made of a transparent or a translucent material that transmits the light emitted by the OLED sheet  204 . 
     Thus, an OLED sheet (e.g., panel) may located below the keycap of each key in a keyboard. The organic layers of the OLED sheet may be deposited or printed (e.g., using inkjet printing or other printing technology). The keyboard may use any type of mechanism (e.g., mechanical, capacitive, or the like) to register a key press. Power may be provided to the OLED sheet by running conductive (e.g., metal) traces inside and/or outside the components of each key mechanism. For example, when a dome-style mechanism is used, the conductive traces may run inside or outside the dome. Of course, other techniques, such as running two wires from the base to the OLED sheet, may be used to provide power. 
       FIG. 3  is a second block diagram illustrating an OLED sheet in a key of a keyboard to illuminate a keycap of the key according to some embodiments.  FIG. 3  illustrates a different perspective of the key mechanism (e.g., one of the keys  112 ( 1 ) to  112 (N) of  FIG. 1 ) illustrated in  FIG. 2 . 
     The key mechanism includes the OLED sheet  204  which is positioned below the keycap  202 . The OLED sheet  204  may be a printed OLED sheet that is inserted between the keycap  202  and a key mechanism, such as the representative key mechanism illustrated in  FIG. 3 . While a dome-type key mechanism, the OLED sheet  204  may be inserted below the keycaps of other types of key mechanisms. The OLED sheet  204  may be thin (e.g., &lt;0.2 millimeters (mm)) and approximately 1 centimeter (cm)×1 cm for regular keys and approximately 1 cm×1.5 cm for larger keys (e.g., ENTER key, SHIFT key, and the like). The term approximate means that the keys may be up to 20% larger or up to 20% smaller than 1×1 cm or 1×1.5 cm. The OLED sheet  204  does not interfere with the operation of whatever type of key mechanism is used. The OLED sheet  204  may include the two contact pads  206 ( 1 ) and  206 ( 2 ) to provide power to an anode and a cathode of the OLED. The two contact pads  206 ( 1 ) and  206 ( 2 ) may be located on the bottom of the OLED sheet  204 . 
     Electrical traces  210  (e.g.,  210 ( 1 ) for the anode and  210 ( 2 ) for the cathode) may be injection molded or printed on one or more components of the key mechanism to carry power to the OLED sheet  204 . For example, the electrical traces  210 , located outside the dome  208 , inside the dome  208 , or partly outside and partly inside, may carry power to the OLED sheet  204 . 
     In a dome-style key mechanism, the dome  208  may run through a hole in the scissor mechanism  212 . The scissor mechanism  212  and/or the dome  208  may hold the keycap  202  above the base  214 . When a user applies pressure to the keycap  202 , the distance between the keycap  202  and the base  214  may decrease. When the distance between the dome  208  and the base  214  is less than a predetermined amount (e.g., 2 mm or less), the keyboard may register a keypress of the key  200 . 
     The base  214  may include the two contacts  216 ( 1 ) and  216 ( 2 ) where power (e.g., direct current (DC)) is applied. The power may travel from the contacts  216 , along the traces  210 , to the pads  206  of the OLED sheet  204 . One of the contacts  216  may connect to a cathode of the OLED sheet  204  and another of the contacts  216  may connect to an anode of the OLED sheet  204 . 
     The keycap  202  may include the illustration  218 , such as an alphanumeric character or a symbol, that is embedded into the keycap  202 . The shape of the OLED sheet  204  may be optimized for each keycap of the keyboard. 
     Thus, an OLED sheet (e.g., panel) may located below the keycap of each key in a keyboard. The keyboard may use any type of mechanism (e.g., mechanical, capacitive, or the like) to register a key press. Power may be provided to the OLED sheet by running conductive (e.g., metal) traces inside and/or outside the components of each key mechanism. For example, when a dome-style mechanism is used, the conductive traces may run inside or outside the dome. Of course, other techniques, such as running two wires from the base to the OLED sheet, may be used to provide power. 
       FIG. 4A  illustrates a scissor mechanism before a key is pressed according to some embodiments. The OLED sheet  204  may be located just below and inside the keycap  202 . The key mechanism illustrated in  FIG. 4A  shows a first portion  402  of a switch that is part of the base  214  and a second portion  404  of the switch that may be part of the scissor mechanism  404 . However, in some embodiments, the second portion  404  of the switch may be part of the dome  208 .  FIG. 4A  shows the scissor mechanism when the keycap  202  is in a normal position in which the key mechanism is not depressed. 
       FIG. 4B  illustrates the scissor mechanism  212  and dome  208  after the keycap  202  is depressed, causing the second portion  404  to make contact with the first portion  402  of the switch, thereby causing the keyboard  104  to register (e.g., indicate to the computing device  102 ) a key press. Depending on the implementation, the keycap  202  may travel between 1 millimeter to 4 millimeters when pressure is applied to the keycap  202 . 
       FIG. 5  is a block diagram illustrating an OLED sheet according to some embodiments. For example, the OLED sheet  204  may include several layers, including a top moisture barrier  502 , an OLED stack  504 , a bottom moisture barrier  506 , and plastic (e.g., polyethylene naphtholate or similar)  508 . The total width of the OLED sheet  204  may be 0.2 mm or less. The OLED stack  504  may be about 100-200 nanometers (nm) in width. 
     The moisture barriers  502 ,  506  may be made of plastic (e.g., polyethylene or the like), polymer-based barrier, atomic layer deposition (ALD), or another type of moisture barrier suitable for OLED. The light emitted by the OLED stack  504  may travel through the bottom moisture barrier  506  and the plastic  508 . The plastic  508  may be transparent or translucent to enable the light from the OLED stack  504  to be transmitted through the plastic  508 . 
       FIG. 6  is a block diagram illustrating layers of an OLED stack according to some embodiments. The OLED stack  504  may be between about 100 to about 200 nanometers (nm) in width and may include a cathode (e.g., negative terminal)  602 , an electron injection layer  604 , a hole blocking layer  606 , an emissive layer  608 , an electron blocking layer  610 , a hole injection layer  612 , and an anode (e.g., positive terminal)  614 . The cathode  602  may inject electrons into the emissive layer  608 . The anode  614  may remove electrons. 
     Power (e.g., direct current) is provided to the OLED stack  504  via the anode  614  and cathode  602 . After power is applied, the cathode  602  receives electrons from the power source and the anode removes them. The added electrons cause the emissive layer  608  to be negatively charged (similar to an n-type layer in a junction diode), while the conductive layers (the layers  610 ,  612 ) become positively charged (similar to p-type material). Positive holes jump boundary from the conductive layer (e.g., layers  604 ,  606 ) to the emissive layer  608 . When a positive hole (a lack of an electron) meets an electron, the two cancel each other out, thereby releasing a brief burst of electromagnetic energy in the form of light (e.g., a photon). This process of a positive hole meeting an electron occurs many times a second, causing the OLED stack  504  to produce light when power is being applied to the cathode  602  and the anode  614 . 
       FIG. 7  illustrates an example configuration of the computing device  102  of  FIG. 1  that can be used to implement the systems and techniques described herein. The computing device  102  may include one or more processors  702  (e.g., a central processing unit (CPU), graphics processing unit (GPU), and the like), a memory  704 , communication interfaces  706  (e.g., Ethernet, Wi-Fi, and the like), a display device  708 , input devices  710  (e.g., the keyboard  104  of  FIG. 1 ), other input/output (I/O) devices  712  (e.g., trackball, and the like), and mass storage devices  714 , configured to communicate with each other, such as via one or more system buses  716  or other suitable connections. While a single system bus is illustrated for ease of understanding, it should be understood that the system buses  716  may include multiple buses, such as a memory device bus, a storage device bus (e.g., serial ATA (SATA) and the like), data buses (e.g., universal serial bus (USB) and the like), video signal buses (e.g., ThunderBolt®, DVI, HDMI, and the like), power buses, etc. 
     The processors  702  are one or more hardware devices that may include a single processing unit or a number of processing units, all of which may include single or multiple computing units or multiple cores. The processors  702  may be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, graphics processing units, state machines, logic circuitries, and/or any hardware device that can manipulate signals based on operational instructions. Among other capabilities, the processors  702  may be configured to fetch and execute computer-readable instructions stored in the memory  704 , mass storage devices  714 , or other computer-readable media. 
     Memory  704  and mass storage devices  714  are examples of computer storage media (e.g., memory storage devices) for storing instructions that can be executed by the processors  702  to perform the various functions described herein. For example, memory  704  may include both volatile memory and non-volatile memory (e.g., RAM, ROM, or the like) devices. Further, mass storage devices  714  may include hard disk drives, solid-state drives, removable media, including external and removable drives, memory cards, flash memory, floppy disks, optical disks (e.g., CD, DVD), a storage array, a network attached storage, a storage area network, or the like. Both memory  704  and mass storage devices  714  may be collectively referred to as memory or computer storage media herein, and may be any type of non-transitory media capable of storing computer-readable, processor-executable program instructions as computer program code that can be executed by the processors  702  as a particular machine configured for carrying out the operations and functions described in the implementations herein. 
     The computing device  102  may also include one or more communication interfaces  706  for exchanging data via a network. The communication interfaces  706  can facilitate communications within a wide variety of networks and protocol types, including wired networks (e.g., Ethernet, DOCSIS, DSL, Fiber, USB etc.) and wireless networks (e.g., WLAN, GSM, CDMA, 802.11, Bluetooth, Wireless USB, ZigBee, cellular, satellite, etc.), the Internet and the like. Communication interfaces  706  can also provide communication with external storage, such as a storage array, network attached storage, storage area network, cloud storage, or the like. 
     The computer storage media, such as memory  704  and mass storage devices  714 , may be used to store software and data. For example, the computer storage media may be used to store an operating system  718  of the computing device  102  and software applications  720 . The memory  704  may also be used to store data  722 . A power source  724  may provide power to the various components of the computing device  102  that use power. The power source  724  may be a power supply (e.g., that converts alternating current to direct current), a battery pack, another type of power source, or any combination thereof. 
     Each of the keys  112  of the keyboard  104  may include a key mechanism, including the OLED sheets  114  placed under the keycaps  202 . For example, the first key  112 ( 1 ) may include the OLED  114 ( 1 ) below the keycap  202 ( 1 ) and the Nth key  112 (N) may include the OLED  114 (N) below the keycap  202 (N). The OLED sheets  114  may emit light to illuminate an illustration (e.g., alphanumeric character or symbol) embedded into each of the keycaps  112 . In some cases, the OLED sheets  14  may be formed into the shape of the illustration and embedded into each of the keycaps  112 . A switch may be used to provide power from the power source  724  to the OLED sheets  114  when the user desires to have the keycaps  202  illuminated and to shut off power from the power source  724  to the OLED sheets  114  when the user powers off the computing device  102  or when the user desires that the keycaps  202  not be illuminated. 
       FIG. 8A  illustrates two OLED sheets under a keycap of a key according to some embodiments. Many keys on a keyboard are multifunction, e.g., pressing the key by itself causes a keypress of a first character or symbol to be registered while pressing the key in conjunction with at least one additional key, such as, for example, a Shift key, a Ctrl (control) key, an Alt (alternate) key, a Fn (function) key, an ESC (escape) key, Windows® key, or the like, may cause a keypress of a second character or symbol to be registered. In this way, a single key may represent multiple characters (e.g., alphabetic characters or numeric characters) or symbols. A key press of one of the multiple characters or symbols is registered based on the key combination that is pressed. 
     For example, the numeric keys on a keyboard may include a numeral  218 ( 1 ) embedded on one portion (e.g., the lower part) of the keycap  202  and a symbol  218 ( 2 ) embedded on another portion (e.g., the upper part) of the keycap  202 . In some cases, a first OLED sheet  204 ( 1 ) may be placed below the numeral  218 ( 1 ) and a second OLED sheet  204 ( 2 ) may be placed below the symbol  218 ( 2 ). Of course, more than two OLED sheets may be used. For example, the number of OLED sheets  204  used under a keycap may vary based on the number of characters or symbols that the key is associated with or the number of characters or symbols embedded  218  into the keycap  202 . 
     To provide power to multiple OLED sheets, multiple metal traces (or wires) may run from the base to the top of the key mechanism, such as the dome  208  illustrated in  FIG. 8D . For example, in  FIG. 8D , for two OLED sheets  204 ( 1 ) and  204 ( 2 ), four metal traces (or wires)  210 ( 1 ),  210 ( 2 ),  210 ( 3 ), and  210 ( 4 ) may run on top of (or inside of) the dome  208  (or other key mechanism). In this example, metal traces  210 ( 1 ) and  210 ( 2 ) may provide power to the OLED sheet  204 ( 1 ) and metal traces  210 ( 3 ) and  210 ( 4 ) may provide power to the OLED sheet  204 ( 2 ). In some cases, only three traces may be used, e.g., two positive and one ground (or negative). 
       FIG. 8B  illustrates a normal (e.g., default) use, in which the first OLED sheet  204 ( 1 ) may be provided power to illuminate the most common usage of the keycap  202 , e.g., the embedded numeral  218 ( 1 ), while power may not be provided to the OLED sheet  204 ( 2 ). When the user presses the shift key or the caps lock key, as illustrated in  FIG. 8C , power may be provided to the second OLED sheet  204 ( 2 ), illuminating the embedded symbol  204 ( 2 ), and power may not be provided to the OLED sheet  204 ( 1 ). In this way, the OLED sheets  204  may be used to illuminate the usage of each key. 
     The example systems and computing devices described herein are merely examples suitable for some implementations and are not intended to suggest any limitation as to the scope of use or functionality of the environments, architectures and frameworks that can implement the processes, components and features described herein. Thus, implementations herein are operational with numerous environments or architectures, and may be implemented in general purpose and special-purpose computing systems, or other devices having processing capability. Generally, any of the functions described with reference to the figures can be implemented using software, hardware (e.g., fixed logic circuitry) or a combination of these implementations. The term “module,” “mechanism” or “component” as used herein generally represents software, hardware, or a combination of software and hardware that can be configured to implement prescribed functions. For instance, in the case of a software implementation, the term “module,” “mechanism” or “component” can represent program code (and/or declarative-type instructions) that performs specified tasks or operations when executed on a processing device or devices (e.g., CPUs or processors). The program code can be stored in one or more computer-readable memory devices or other computer storage devices. Thus, the processes, components and modules described herein may be implemented by a computer program product. 
     Furthermore, this disclosure provides various example implementations, as described and as illustrated in the drawings. However, this disclosure is not limited to the implementations described and illustrated herein, but can extend to other implementations, as would be known or as would become known to those skilled in the art. Reference in the specification to “one implementation,” “this implementation,” “these implementations” or “some implementations” means that a particular feature, structure, or characteristic described is included in at least one implementation, and the appearances of these phrases in various places in the specification are not necessarily all referring to the same implementation. 
     Although the present invention has been described in connection with several embodiments, the invention is not intended to be limited to the specific forms set forth herein. On the contrary, it is intended to cover such alternatives, modifications, and equivalents as can be reasonably included within the scope of the invention as defined by the appended claims.