Abstract:
A button assembly includes a button structure ( 110 ) mounted to a frame ( 104 ) by a flexible hinge ( 108 ), where the button structure ( 110 ) has a clear external surface ( 102 ) and a graphical overlay ( 112 ) behind the external surface; and a light pipe ( 114 ) mounted to the button structure ( 110 ) and contacting 5 an actuator ( 118 ) that is configured to trigger when pressure is applied, where the light pipe ( 114 ) is configured to trigger the actuator ( 118 ) when pressure is applied to the button structure ( 110 ) and where the light pipe ( 114 ) is further configured to propagate light from a light source ( 116 ) to the button structure ( 110 ) to illuminate the graphical 10 overlay ( 112 ) and to minimize light leakage.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/903,732, filed Nov. 13, 2013 and U.S. Provisional Application Ser. No. 62/041,857, filed Aug. 26, 2014, which is incorporated by reference herein in its entirety. 
       TECHNICAL FIELD 
       [0002]    The present invention generally relates to buttons and, more specifically, to illuminated graphical actuation buttons. 
       BACKGROUND 
       [0003]    Consumer and market preference for electronic devices such as set top boxes, computers, game consoles, DVD players, CD player, etc., is to have such devices be compact. However, it is difficult to keep devices small, because set top boxes are required to perform more functions, which implies that they are contain more internal components. 
         [0004]    One place this becomes apparent is in the use of buttons on the device. Such buttons are often made compact for aesthetic reasons and to inhibit electrostatic discharge, which can make it difficult to see a graphic on the button. Designs for such buttons are compact and coordinated with other features to optimize the space within the devices. Furthermore, manufacturing tolerances mean that there will inevitably be gaps in the design between the button and an enclosure. 
         [0005]    Currently, the graphics are often too difficult to read without illumination. However, providing backlighting can result in unacceptable leaks of light visible when the illumination is activated, due to the gaps between the button and the enclosure. 
         [0006]    Graphics on buttons are usually positioned behind another surface to protect them from rubbing off during repeated use. The front protective surface is captured in an opening in an enclosure and must be free to actuate when pressed by a customer. 
         [0007]    To enable parts to be mass produced with the lowest cost possible, there are often minimum thicknesses and tolerances. Getting good graphic detail close enough to the front surface can therefore also be difficult. 
       SUMMARY 
       [0008]    A button assembly includes a button structure mounted to a frame by a flexible hinge, said button structure having a clear external surface and a graphical overlay behind the external surface; and a light pipe mounted to the button structure and contacting an actuator that is configured to trigger when pressure is applied, wherein said light pipe is configured to trigger the actuator when pressure is applied to the button structure and wherein said light pipe is further configured to propagate light from a light source to the button structure to illuminate the graphical overlay and to minimize light leakage. 
         [0009]    A button assembly includes a button structure mounted to a frame by a flexible hinge, said button structure having a clear external surface and a graphical overlay behind the external surface; a button light pipe mounted to the button structure and contacting an actuator that is configured to trigger when pressure is applied, wherein said button light pipe has a button-facing surface that is larger than an actuator-facing surface, wherein said button light pipe is configured to trigger the actuator when pressure is applied to the button structure, and wherein said button light pipe is further configured to propagate light from a button light source to the button structure to illuminate the graphical overlay and to minimize light leakage; an illuminated indicator that comprises a cylindrical indicator light pipe that extends from an indicator light source and propagates light from the indicator light source to an exposed external surface; and a printed circuit board, wherein the actuator, the button light source, and the indicator light source are mounted to the printed circuit board. 
         [0010]    A method for illuminating a button with minimal light leakage includes providing a light pipe in contact with an actuator; illuminating a graphical overlay by illuminating the light pipe with a light source, wherein the light pipe conveys light from the light source to a button structure to illuminate the graphical overlay and to minimize light leakage, wherein the button structure is mounted to a frame by a flexible hinge; and generating an actuator signal when the button structure is depressed, causing the light pipe to trigger the actuator. 
         [0011]    The present principles include a set top box comprising an enclosure, a printed circuit board within the enclosure and the button assembly positioned over, under or adjacent to the printed circuit board within the enclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which: 
           [0013]      FIG. 1  is an exploded view of an illuminated button assembly according to the present principles within an electronic device such as a set top box; 
           [0014]      FIG. 2  is a frontal view of an illuminated button assembly according to the present principles; 
           [0015]      FIG. 3  is a perspective view of an illuminated button assembly according to the present principles; 
           [0016]      FIG. 4  is an underneath perspective view of an illuminated button assembly installed in an enclosure according to the present principles within the electronic device; and 
           [0017]      FIG. 5  is a flow chart highlighting the method for illuminating a button according to the present principles. 
       
    
    
       [0018]    It should be understood that the drawings are for purposes of illustrating the concepts of the invention and are not necessarily the only possible configuration for illustrating the invention. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0019]    Embodiments of the present invention provide illuminated graphical buttons using a light guide to minimize light leakage. A button assembly is provided that has a clear front lens that fits into an opening in an electrical enclosure. The front surface of the front lens is as thin as possible to maximize visibility. A sheet overlay of plastic with translucent and opaque graphics is assembled inside the clear front lens. The front lens is fixed to the movable portion of an opaque plastic frame. The opaque plastic frame is a single molded piece and has a center portion connected by flexible hinges to a rigid outer frame that mounts to the surrounding enclosure. 
         [0020]    The opaque plastic frame has light blocking side walls that telescope into the inside perimeter of the clear front lens. These walls press against the perimeter of the rear surface of the graphics sheet overlay and create a light-proof barrier. The overlap of the telescoping side walls of the opaque plastic frame and the sheet overlay prevents visible light leaks when the illumination is activated. Because the graphics sheet overlay fits inside the clear front lens, the graphics are very close to the front surface and are clearly visible even without the rear illumination. 
         [0021]    A translucent light pipe is fixed to the opaque plastic frame and presses against the back of the sheet overlay. The fixation may be accomplished by heatstaking or press fitting. Light from, e.g., a light emitting diode (LED) on a printed circuit board (PCB) is transmitted through the light pipe to illuminate the back of the sheet overlay. The light pipe also translates motion from the customer pressing the front lens of the button assembly to an actuator of a switch. 
         [0022]    Referring now in specific detail to the drawings in which like reference numerals identify similar or identical elements throughout the several views, and initially to  FIG. 1 , an exploded view of an illuminated graphical button in accordance with the present embodiments is shown. A clear front lens and button  102  is shown. 
         [0023]    The button and lens  102  are externally accessible and are configured to withstand the pressure of a user&#39;s finger when pressing the button. The button  102  is mounted on a button support piece  110  which, in turn, is connected to a frame  104  by a flexible hinge  108 . The button  102  may be fixed to the button support piece  110  by e.g., heatstaking or press fitting. The button support piece  110  is located within an open center region of the frame  104  and the flexible hinge  108  may be any suitable structure that allows motion of the button support piece  110  transverse to a plane of the frame  104 . The frame  104  is fixed to an enclosure of the device by, e.g., heatstaking or press fitting. It is contemplated that the hinge  108  may be formed as shown, with thin pieces of material connecting the button support piece  110  to the frame  104 , but it is also contemplated that the hinge  108  may be formed from, e.g., a spring or elastic material. The button  102  may have alignment rods extending rearward from peripheral edges that engage holes in the button support piece  110 . 
         [0024]    A sheet overlay  112 , which is contemplated as being a translucent sheet with graphics, can be positioned on the interior side of the button  102  and centered around the button support piece  110 . A light pipe  114  is provided which can be a solid transparent or translucent material that transmits light and which provides a structural, mobile mechanical connection between the button  102  and a switch actuator  118 . When the button  102  is pressed, pressure is applied via the light pipe  114  to the switch actuator  118 . The light pipe  114  is therefore positioned between the sheet overlay  112  and the actuator  118 . The light pipe  114  may be fixed into place with, e.g., heatstaking or press fitting. In one specifically contemplated embodiment, the light pipe  114  has an actuator-contact end facing the actuator  118  that is narrow and a button-facing end that that extends from the narrow end and widens as it approaches the button  102  to produce a tapered shape. The light pipe  114  may be conical or may have a rectilinear cross section. The switch actuator  118  may include an actuator on a vertical surface that faces a front wall of a device enclosure. 
         [0025]    A button light source  116  is mounted on a PCB  130  with the actuator  118  and may be, e.g., an LED or any other suitable light-emitting device. The light pipe  114  is positioned over or directly on the light source  116  and redirects emitted light toward the button  102  with little or no leakage. Light from the button light source  116  enters the light pipe  114  and reflects off of interior surfaces to propagate toward the button  102 . Additionally, if the light pipe  114  is translucent, the light may reach the button by scattering, rather than reflection off of interior surfaces. The surface of the wide end of the light pipe  114  may be textured to help with light distribution and to obscure the shape of the button light source  116 . 
         [0026]    Optionally, an additional light source  128  may be provided on the PCB  130 . This light source may function as an indicator light for, e.g., a status indicator that shows that some action is being performed. For example, the additional light source may represent a “record” function to indicate that the device is storing data. As above, the additional light source  128  may be an LED or any other appropriate light emitting device. A light pipe  126  rests over or on the additional light source and redirects light to a visible indicator  120  that fits through an aperture  106  in the button frame  104 . A support flange  124  may connect with the frame  104  and a device enclosure to provide support to the light pipe  126 . It is contemplated that the light pipe  126  may have a cylindrical horizontal portion that runs rearward to a bent section that makes contact with the additional light source  128 . 
         [0027]    Referring now to  FIG. 2 , an enlarged diagram of the frame  104  is shown. The button frame  104  is attached to the support flange  124 , which in turn is attached to the PCB  130 . 
         [0028]    Referring now to  FIG. 3 , a rear perspective view of the button assembly is shown. In particular,  FIG. 3  illustrates how the button support  110  may be connected to the button  102  (not shown) and the light pipe  114  using heat stakes  302 . The heatstakes  302  are melted to secure the components in place. 
         [0029]    Referring now to  FIG. 4 , the button assembly is shown installed in an enclosure  402  of the electronic device. The frame  104  of the assembly engages with a slot  404  of a housing  406 . When the enclosure is closed, the button assembly is positioned over the PCB  130  such that the light pipes  114  and  126  are above the respective light sources  116  and  128  and such that the button light pipe  114  contacts the actuator  118 . 
         [0030]    The method for illuminating a button with minimal light leakage in described in  FIG. 5 . Step  501  includes providing a light pipe in contact with an actuator. Step  502  includes illuminating a graphical overlay by illuminating the light pipe with a light source, wherein the light pipe conveys light from the light source to a button structure to illuminate the graphical overlay and to minimize light leakage, wherein the button structure is mounted to a frame by a flexible hinge. Step  503  includes generating an actuator signal when the button structure is depressed, causing the light pipe to trigger the actuator. 
         [0031]    A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made. For example, elements of different implementations may be combined, supplemented, modified, or removed to produce other implementations. Additionally, one of ordinary skill will understand that other structures and processes may be substituted for those disclosed and the resulting implementations will perform at least substantially the same function(s), in at least substantially the same way(s), to achieve at least substantially the same result(s) as the implementations disclosed. Accordingly, these and other implementations are contemplated by this disclosure and are within the scope of this disclosure. 
         [0032]    The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.