Abstract:
An input device, such as a mouse or trackball, with a top housing having an integrally formed, free extending top button. The top housing is mounted so that the extending button is supported in cantilevered fashion. The button is sufficiently flexible to allow it to be depressed for button activation.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention relates to computer mice or track balls, and in particular to buttons on such devices.  
         [0002]     In one type of computer mouse, a ball protrudes from the bottom of the mouse housing, and rolls across a supporting surface. The movement of the ball is typically detected by shafts which are in contact with the ball and turn an encoder wheel having a number of slots. Track balls will have a ball mounted on the top with the housing being stationary, but similarly operate with two encoder wheels at 90° angles to detect X and Y movement. Optical mice and trackballs have also been developed.  
         [0003]     Such mice and track balls typically also have buttons which can be depressed or clicked by a user, and which depress a switch (microswitch, pancake, optical, etc.). These provide additional inputs to the computer, in addition to the position of the mouse or trackball. Some mouse designs have added a roller or wheel which can be used for such functions as scrolling or zooming. The roller is operated by a user finger much like a dial on a radio.  
         [0004]     A button is typically formed by one or more plastic keyplates, which attach to the underside of the top housing of the mouse or trackball. The keyplate covers a part of the mouse, and there is a gap between the keyplate and the rest of the top housing, or adjacent keys. Beneath the keyplate, inside the device, a microswitch is mounted to be activated when the keyplate is depressed.  
       BRIEF SUMMARY OF THE INVENTION  
       [0005]     The present invention provides an input device with a top housing having an integrally formed, free extending top button. The top housing is mounted so that the extending button is supported in cantilevered fashion. The button is sufficiently flexible to allow it to be depressed for button activation.  
         [0006]     In one embodiment, the device is a mouse. The top housing and button are formed of a single piece of metal. The metal is a flat piece, bent around the back of the mouse to secure it. The design eliminates the need for any features on the metal, making it easy to manufacture and giving it a clean appearance. An island separates two buttons at the front of the mouse. A roller extends through a slot in the island. The island includes lips which overlap the edges of the buttons, so that no gap is visible from above, giving the mouse a clean look.  
         [0007]     In one embodiment, an interior non-metalic housing isolates the metal top housing from the interior electrical components. Inside the interior housing are cantilevered arms for actuating buttons in response to the metal buttons or roller being pressed. When a metal housing button is depressed, it presses down on an actuator pip extending through the interior housing, causing the arm to depress a microswitch mounted on a circuit board beneath the arm.  
         [0008]     For a further understanding of the nature and advantages of the invention, reference should be made to the following description taken in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a perspective view of an embodiment of the top housing of the invention mounted on a mouse.  
         [0010]      FIG. 2  is an exploded view of the top interior housing and the metallic exterior housing functioning as a button.  
         [0011]      FIG. 3  is an exterior view of the top interior housing.  
         [0012]      FIG. 4  is an exploded view of the top interior housing and the metallic exterior housing with a single fixing point for attaching the exterior housing to the top interior housing.  
         [0013]      FIG. 5  is an exterior view of the metallic top housing with the roller removed.  
         [0014]      FIG. 6  is a perspective view of the underside of the exterior housing, top interior housing, cantilevered arm and roller of one embodiment of the invention.  
         [0015]      FIG. 7  is a perspective view of the bottom portion of the body of the mouse showing the circuit board placement and an insulating and ESD protecting membrane around an optical element. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]      FIG. 1  is a perspective view of one embodiment of a mouse according to the present invention. The mouse has a top, exterior metallic housing  100 . The metallic top housing  100  is mounted over a mouse body  107 . The housing  100  has two extending buttons  102  and  103 , which extend on either side of a island  120  mounted on body  107 . A roller  20  extends through island  120 . Metal housing  100  has a rear, curved portion  108  which wraps around the back of the mouse. Inside curved portion  108  is a rubber bumper  109  to provide additional impact protection so the mouse can pass a drop test. The metal top housing is flexible, and is secured only toward the back of the mouse. Thus, buttons  102  and  103  are free to be depressed, to actuate switches inside mouse body  107 . This structure allows a simple metal top housing that is smooth, without requiring any features to be formed in it, as in prior art keyplates. It has a clean, streamlined look, and no gap is visible between the buttons  102 ,  103  and the island  120  because the island has lips extending over the buttons, as will be more clearly shown insubsequent figures.  
         [0017]      FIG. 2  shows an exploded view of a top interior housing  101  and the metallic exterior housing  100 . As can be seen better here, buttons  102  and  103  extend from the top housing, and are free floating, with the housing only being anchored at the rear of the mouse.  FIG. 2  also shows slots  107  and  107 ′ in the top interior housing  101 , through which actuator pips extend as shown in  FIG. 3 , below, to actuate the microswitches. When the metal housing  100  is depressed, it presses down on a actuator pips extending through the slots  107  and  107 ′ in the top housing  101 , and causing the arm to depress a microswitch mounted on a circuit board beneath the arm.  
         [0018]      FIG. 3  illustrates the exterior appearance of the top interior housing  101 . Roller  20  extends through the slot  110  of the top interior housing. Tabs (actuator pips)  17 ,  17 ′ on an interior cantilevered arm (shown below) for each button also extends through the slot of the top interior housing  101 . When a metal housing mounted over the interior top housing is depressed, it presses down on a actuator pips  17  and  17 ′ and causes the arm to depress a microswitch mounted on a circuit board beneath the arm.  
         [0019]      FIG. 4  shows another view from the bottom of the metal exterior housing  100  functioning as a button mounted over the top interior housing  101 . The button  100  is attached to the interior housing  101  at one fixing point  119  only. This is shown with a screw or other fastener  118  attaching to fixing point hole  119 . Alternately, a press fit against an overhanging ledge of island  120  could be used, or any other form of attachment. In addition, the back of the metal housing wraps around and press-fits, snap attaches, or is loosely located against the back of the mouse. This provides a pivot point for the depression of the front button portions  102 ,  103  of the metal housing. It also allows flexion of the back, curved portion to provide a distribution of impact forces in a drop test to avoid damage to the internal components of the mouse. Fixing at point  119  and loose location at the back allows flexion of the curved portion which also reduces the overall force required by the user to activate the key.  
         [0020]      FIG. 5  shows a front exterior view of the metallic top housing  100  with the roller removed. The actuator pips shown in  FIG. 3  are hidden by the exterior top housing  100 . The island  120  has ledges or lips  122  and  124  which extend over the edges of buttons  102  and  103 . This elimates any visible gap from above, giving a clean, streamlined look to the mouse. In addition, ledges  122  and  124  limit the upward travel of the buttons  102  and  103 , which are mounted so that their flexion biases them up against the underside of ledges  122  and  124  when the buttons aren&#39;t depressed. Alternately, there may be no upward force against the underside of the ledges. This provides a stop for upward travel of the buttons, again simplifying the design compared to prior art keyplates.  
         [0021]      FIG. 6  is a perspective view of the underside of exterior housing  100  and top interior housing  101  with an internal plastic keyplate  12  mounted on the top interior housing according to one embodiment of the invention. The exterior housing  100  is preferably made of metal, and acts as two buttons in addition to functioning as the exterior housing. The top interior housing  101  has two pegs  105 ,  105 ′ proximate the rear of the top housing. The pegs snap fit into the keyplate to attach the keyplate to the interior housing by engaging two sockets  15  in internal keyplate  12 . The pegs are loosely located in the keyplate to avoid the metal popping out in a drop test. The loose location has a benefit of providing the drop test assistance and not requiring precise tolerances. The internal keyplate  12  is formed of three cantilevered arms  14 ,  16 , and  18 . The ends of the side arms  16  and  18  serve as side buttons  166  and  188  (left and right click buttons) when depressed by a user finger on the corresponding button portion of exterior housing  100 . The cantilevered arms  14 ,  16 , and  18  are formed of an integral piece of plastic and are connected proximate the rear of the keyplate  12  and the top housing  100 .  
         [0022]     Middle cantilevered arm  14  supports a roller  20  attached on the end of the arm  14 , proximate the front of the plate  12  and the top housing. The middle arm  14  has a protrusion  144  that serves to activate an underlying microswitch when the roller is depressed. The arm  14  has a spring force to bias the roller upward, eliminating the need for a return spring, in contrast with a typical prior art mouse that has a complex support structure for a roller mounted on the bottom housing and that needs a lift spring to bias the roller upward.  
         [0023]     The interior plastic housing provides insulation for the mouse. The use of a metal exterior housing presents issues with electrostatic discharge (ESD) harming the internal electronic components. The use of the interior plastic housing isolates the metal top housing from the internal components. The uses of the interior cantilevered plastic arms isolates the metal buttons from the internal microswitches. The interior housing also provides a stop for downward travel of the metal buttons.  
         [0024]      FIG. 7  illustrates the layout of a printed circuit board (PCB)  44 , outlined in phantom, and mounted on a lower housing  40  of the mouse. On the printed circuit board is mounted a light emitter, such as a light emitting diode (LED)  48 . LED  48  is on one side of the roller, while on the other side, opposite LED  48 , is a photo detector  50 . As the roller is rotated, the slots  64  alternately block and let light pass from emitter  48  to detector  50 .  
         [0025]      FIG. 7  also shows microswitches  52  and  54  which are placed beneath the two side buttons  166  and  188  at the end of each of the cantilevered arms  16  and  18  of  FIG. 6 . In addition, a third switch  56  is provided to be activated by a protrusion  144  on the cantilevered arm  14 , that serves as a third button when the roller is depressed, visible in  FIG. 6 . The microswitches  52 ,  54  and  56  as well as an optical module  47  are mounted on the circuit board  44 .  
         [0026]     As will be apparent to those skilled in the art, the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. For example, the exterior top housing functioning as a button could be plastic. Also the exterior top housing could have one or three buttons instead of two. The metalic housing could be mounted on a trackball, with a ball extending through a gap in the metal, and an island on the other side of the ball from the anchoring portion of the metal housing. Accordingly, the foregoing description is intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims.