Abstract:
An apparatus such as a wireless telephone is disclosed, the apparatus having a screen with an icon, and an input device for controlling the icon on the screen. The input device includes a sensor adapted to detect movement and a captive disc movably suspended over the sensor, the captive disc having an active surface facing the sensor and the sensor viewing a portion of the active surface. When the captive disc is moved, the sensor detects differing portions of the active surface and determines movement by changes in its view. Because the captive disc is substantially flat, the input device can be relatively small in size compared to input devices of the current art. The smaller size requirement is advantageous for implementing the input device in various devices including the PDAS, wireless communication devices, and other electronic equipment.

Description:
BACKGROUND 
     The present invention relates to computer input devices, and more particularly, to input devices for movement of computer icons on a screen. 
     Various input devices are in use for manipulating icons such as mouse pointers on screens of computers and various electronic devices. For example, computer mice and trackballs are popular as input devices for desktop computers. 
     For portable devices (such as personal digital assistants (PDAS) and cellular telephones), touch sensitive pads, joystick controls (for example pointing sticks), and push buttons are popular. However, each of these devices has drawbacks. For example, touch pads require a relatively large input area. In small devices such as wireless telephones, surface area is at a premium. Joystick controls have poor user feedback. This is because joystick controls typically do not move at all; rather, pressure sensors are used to detect user input. Push buttons allow movements only in discrete directions rather than movements in all directions. 
     Accordingly, there remains a need for a pointing device that eliminates or alleviates these shortcomings. 
     SUMMARY 
     The need is met by the present invention. According to a first embodiment of the present invention, an input device includes a sensor adapted to detect movement and a captive disc movably suspended over the sensor. The captive disc has an active surface facing the sensor. 
     In a second embodiment of the present invention, an input device includes a sensor adapted to detect movement and a captive disc movably suspended over the sensor. The captive disc has an active surface facing the sensor. The input device further includes an illuminant adapted to provide light toward the active surface and a focusing lens focuses light from the active surface onto the sensor. Finally, a horizontal spring is adapted to center the captive disc over the sensor. 
     In a third embodiment of the present invention, an electronic apparatus includes a screen displaying information including an icon and an input device for controlling the icon. The input device includes a sensor adapted to detect movement and a captive disc movably suspended over the sensor. The captive disc has an active surface facing the sensor. 
     Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a simplified front view of an apparatus in accordance with one embodiment of the present invention including an input device of the present invention; 
         FIG. 2A  illustrates a more detailed front view of a portion of the apparatus of  FIG. 1  including the input device of the present invention; 
         FIG. 2B  illustrates a cut-away side view of the input device illustrated in  FIG. 2A  cut along line A-A; 
         FIG. 2C  illustrates various vertical positions of a portion of the input device illustrated in  FIGS. 2A and 2B ; 
         FIG. 2D  illustrates one embodiment of a surface of a captive disc of the input device illustrated in  FIGS. 2A through 2C ; 
         FIG. 2E  illustrates a return movement of a portion of the input device illustrated in  FIGS. 2A and 2C ; and 
         FIG. 3  illustrates a second embodiment of the input device in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described with reference to  FIGS. 1 through 3 , which illustrate various embodiments of the present invention. As illustrated in the Figures, relative sizes of various portions, structures, or any combination of these are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of the present invention. 
     Various aspects of the present invention are described with reference to a device having a layer, a region, or a structure being on or above other layers, regions, or structures. As will be appreciated by those of skill in the art, references to a layer, a region, or a structure being formed “on” or “above” another layer, another region, or another structure contemplate that additional layer, region, or structure may intervene. References to a layer, a region, or a structure being formed on or above another layer, another region, or another structure without an intervening layer, region, or structure are described herein as being formed “directly on” or “directly above” the other layer, the other region, or the other structure. 
     Further, relative terms such as “under” or “beneath” may be used herein to describe one layer, region, or structure&#39;s relationship to another layer, region, or structure as illustrated in the Figures. It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. For example, if the device in the Figures is turned over, layers, regions, or structure described as “under” or “beneath” the other layer, region, or structure would now be oriented “over” or “above” these other layers, regions, or structures. As such, the terms “under” or “beneath” are intended to encompass both over and above depending upon orientation of the Figures, context, or both in such situations. Likewise, the terms “over” or “above” are intended to encompass both under and beneath depending upon orientation of the Figures, context, or both in such situations. Additionally, terms “over” and “under” are intended to encompass relative positional phrases “right of” or “left of” in case such devices or apparatuses are turned on its side, and “front of” or “back of” in case such devices or apparatuses are turned on its end. Like numbers refer to like elements throughout. 
     As shown in the figures for the purposes of illustration, one embodiment of the present invention is exemplified by an electronic apparatus, for example a PDA or a wireless mobile communication device. The sample apparatus includes a screen displaying an icon such as a cursor or an arrow-type pointer. The apparatus is configured or programmed to have the pointer move around the screen in response to input from an input device having a sensor and a captive disc. 
     The input device of the present invention requires less space than a touch pad, allows movements in all directions, and provides feedback to the user via actual movements of the captive disc. Accordingly, the input device of the present invention eliminates or alleviates the shortcomings of the prior art devices. 
       FIG. 1  illustrates a simplified front view of an apparatus  10  in accordance with one embodiment of the present invention including an input device of the present invention. The apparatus  10  includes a screen  12  for displaying information including an icon  14  such as a pointing arrow or a cursor. The apparatus  10  includes an input device  20  for controlling the icon. The input deice  20  is accessible to a user via a front opening  22 . The apparatus  10  can include other input devices such as input buttons  16  or even a keyboard (not illustrated). The apparatus  10  can be, for example, wireless communication device such as a cellular telephone. 
       FIG. 2A  is a more detailed front view of portions of the apparatus  10  of  FIG. 1  including the input device  20 .  FIG. 2B  is a cut-away side view of the input device  20  illustrated in  FIG. 2A  cut along line A-A.  FIG. 2C  illustrates different operating states of the input device  20  illustrated in  FIG. 2A .  FIG. 2D  illustrates one embodiment of a surface of a captive disc of the input device illustrated in  FIGS. 2A through 2C . 
     Referring to  FIGS. 2A to 2D , the input device  20  includes a sensor  24  adapted to detect movement. Motion is detected, quantified, and reported by the optical navigation sensor  24  such as the model ADNS-2030 available from Agilent Technologies, Inc. Other models from Agilent as well as other sensors from other manufacturers can be used. The sensor  24  uses an integrated circuit to capture images of the tracking surface. Successive images are compared mathematically to determine the magnitude and the direction of motion in the X and Y axes. The sensor  24  has a communication port to pass the displacement values to other circuits and electronics  46 . The sensor  24  detects movements of a captive disc  26  which is movably suspended over the sensor  24  by a horizontal spring  28  and a vertical spring  30 . 
     The captive disc  26  has an active surface  25  that faces, or is directed toward, the sensor  24  and a user surfaces that is directed away from the sensor  24 .  FIG. 2D  illustrates one embodiment of the active surface  25 . The term “spring” used herein includes any and all materials, structures, or both configured to provide spring and spring-like functions described herein and includes, without limitation, metallic springs, elastomer blocks, gel bags, and other structures. Furthermore, the horizontal and vertical springs  28  and  30  can be implemented as one structure providing horizontal and vertical tensions and pressures described herein. For convenience, the horizontal and vertical springs  28  and  30  are discussed herein as two separate entities. 
     The captive disc  26  is movable within its plane in any direction along the X-axis, Y-axis (as defined by the plane of the disc  26  itself), or in any combination of these axes. The horizontal spring  28  surrounds the captive disc  26  and provides horizontal tension toward the center. At rest position, the captive disc  26  is at the center of a frame  32  housing the captive disc  26  as illustrated in  FIG. 2A . For clarity, movements of the captive disc  26  within its plane is referred to as horizontal movements or movements in X and Y axes. The frame  32 , along with the captive disc  24 , provides an enclosed and protected space within the frame  32  for protection against external contaminants such as dirt, liquid, or other foreign particles. 
     Additionally, the captive disc  26  is movable vertically, in Z-axis as illustrated in  FIGS. 2B and 2C . The vertical spring  30  supports the captive disc  26  and provides vertical tension toward the front (as illustrated in  FIGS. 1 and 2A ) or top (as illustrated in  FIG. 2B ).  FIG. 2C  illustrates the captive disc  26  in three different vertical positions, or planes. At the rest position, vertical tension from the vertical spring  30  pushes the captive disc  26  “up” toward the opening  22  resulting in the captive disc  26  resting against the opening  22  at a rest plane. This is illustrated in  FIG. 2C  as the captive disc  26   a . The frame  32  defines a frame area, for example, a circular area, having a frame radius  50 . The captive disc  26  has a disc radius  52 . 
     When pressure is applied to the captive disc  26   a  (such as by a finger  36  of a user), the captive disc  26   a  is pushed “down” to a focal plane level. The captive disc  26  at the focal plane level is illustrated in  FIG. 2C  as captive disc  26   b . In  FIG. 2B , the captive disc  26  is illustrated at the focal plane level. To select an item on the screen  12  of  FIG. 1 , the captive disc  26  is pushed further down to a selection plane level thereby activating a selection switch  34 . The captive disc  26  at a selection plane level is illustrated in  FIG. 2C  as captive disc  26   c . Activation of the selection switch  34  is analogous to pressing a button on a traditional computer mouse. 
     For convenience, the captive disc  26 , generically, is referred to using reference numeral  26  except when discussing specific vertical position of the captive disc  26  where reference numerals  26   a ,  26   b , and  26   c  are used to refer to the captive disc  26  at the rest position, focal plane level, and selection plane level, respectively. For clarity, “up” and “down” movements of the captive disc  26  is referred to as movements in Z-axis. 
     The captive disc  26 , the horizontal spring  28 , and the vertical spring  30  are housed within a frame  32 . The frame  32  can be defined by the apparatus  10 . The horizontal spring  28  is within the frame  32  and is supported by the frame  32 . The vertical spring  30  is within the frame  32  and is supported by the frame  32 . 
     As illustrated, in one embodiment of the present invention, the captive disc  26  is substantially flat. Accordingly, the input device  20  requires much less space than some other input devices such as a trackball that uses a spherical ball. 
     A light source  38  provides illumination for the active surface  25  of the captive disc  26 . Light reflecting from the active surface  25  is focused on the sensor  24  by focusing lens  40 . The sensor  24  and the focusing lens  40  can be designed to have a relatively narrow depth of field to minimize the size of the input device  20 ; however, the depth of field of the sensor  24  is implementation dependent. The lens  40  may not be necessary depending on the maximum focal distance  42  of the sensor  24  and the distance between the sensor  24  and the active surface  25 . When present, the focusing lens  40  focuses light from a portion of the active surface  25  to the sensor  24  when the active surface  25  is at or proximal to the focal plane level  26   b . In some implementations, the light from the light source  38  can be focused on the active surface  25  using a light source lens, separate from the focusing lens  40 . To avoid clutter, the light source lens is not illustrated in the Figures. 
     In the embodiment illustrated in  FIGS. 1 through 2E , the sensor  24  is adapted to sense images at or proximal to a focal area  44  within a focal distance range  43 . The focal distance range  43  is a range of focal distances from the sensor  24  within which the sensor  24  is focused. The focal distance range  43  is between a maximum focal distance range  42  and minimum focal distance range  45  of the sensor  24 . Here, phrase “focal plane” includes any plane having X-Y axes that is within or proximal to the focal distance range  43  in Z-axis. The sensor  24  views and detects changes of patterns that fall within the focal area  44  and converts these changes as movements of the captive disc  26  provided that the captive disc  26  is at a distance that is within the focal distance range  43 . This configuration can be accomplished by internal design of the sensor  24  or more often by using the focusing lens  40 . The focal area  44  is a relatively small area within the focal plane. 
     The captive disc  26  has the active surface  25  one embodiment of which is illustrated in  FIG. 2D . Continuing to refer to  FIGS. 2A through 2D , the active surface  25  includes a navigation area  25   a  and a border area  25   b  generally surrounding the navigation area  25   a . The navigation area  25   a  generally occupies center of the active surface  25  in a circular fashion (for a circular disc) has a predetermined pattern. The predetermined pattern can be a random pattern or a designed navigable pattern. The predetermined pattern can be designed such that changes in the predetermined pattern (from movements of the captive disc  26 ) are easily interpreted by the sensor  24 . Radius  56  of the navigation area can be, for example, approximately 80 percent of the radius  52  of the disc  26 . 
     In the illustrated sample embodiment of  FIG. 2D , the navigation area  25   a  is a random area. The border area  25   b  is also a random surface which has lower density than the navigation area  25   a . Therefore the disc  26  can be used for tracking, and for border detection. The lower density area  26   b  could be made to defocus more quickly than the center for undesired motion suppression. 
     Initially, the captive disc  26  is at a rest plane as captive disc  26   a . At this state, the active disc  25  is out of the focus of the sensor  24 . Here, the user is represented by the finger  36  in  FIG. 2B . To move the icon  14  of  FIG. 1 , the finger  36  presses the captive disc  26  moving the captive disc  26  in Z-axis such that the active surface  25  comes within the focal plane thereby bringing portions of the active surface onto focus of the sensor  24 . Further, initially, captive disc  26  is centered relative to the frame  32  or the opening  22 . Therefore, the sensor  24  views the center of the navigation area  25   a . Pushing the captive disc  25  down causes the active surface  25  to come into focus and its motions in the X-Y direction are reported by the sensor  24 . 
     As the captive disc  26  is moved (in the X-axis and the Y-axis directions) within the focal plane (in the Z-axis), different portions of the navigation area  25   a  enters and leaves the focal area  44  projected onto (thus viewed by) the sensor  24 . The sensor  24  detects the movements and communicates the movements to circuits and electronics  46  outside the input device  20  but internal to the apparatus  10  of  FIG. 1 . Also connected to the electronics  46  are the light source  38  and the selection switch  34 . For convenience, movements of the captive disc  26  in the X-axis, in the Y-axis, or a combination of these axes are referred to as horizontal movements; movements of the captive disc  26  in the Z-axis are referred to as vertical movements. 
     The frame  32  limits the horizontal movements of the captive disc  26 . In fact, horizontally, the captive disc  26  is limited to movements, in any one direction, to a horizontal clearance  54  value where the horizontal clearance is the difference between the frame radius  50  and the captive disc radius  52 . After moving the captive disc  26 , in any horizontal direction, to the end of its horizontal clearance, the user releases the captive disc  26  to allow it to return to its rest position  26   a  so that the captive disc  26  can be used again. 
       FIG. 2E  illustrates the return movement  51  of the captive disc  26  from the end of its horizontal clearance (represented by captive disc  26   d ) to its rest position (represented by captive disc  26   a ). Referring to  FIGS. 2A through 2E , when the captive disc  26   d  is released, pressure from the horizontal spring  28  moves the captive disc  26   d  toward horizontal center of the frame  32 . Further, the vertical spring  30  moves the captive disc  26   d  up beyond the focal length  42  of the sensor  24 . For this reason, during the return movement of the captive disc  26  from the end of its horizontal clearance position  26   d  to its rest position  26   a , the active surface  25  of the captive disc  26  is out of focus of the sensor  24 . Therefore, no movement is detected by the sensor  24 , thus the icon  14  of  FIG. 1  is not moved. Then, after the captive disc  26  returns to its rest position  26   a , it is moved again if further movement of the icon  14  of  FIG. 1  is desired. 
     During the return movement of the captive disc  26   d , tensions from the horizontal spring  28  and the vertical spring  30  act simultaneously. That is, the captive disc  26   d  can begin movements in the horizontal direction before the captive surface  25  is completely out of the focus of the sensor  24 . In this situation, the return movement of the captive disc  26  may cause the icon  14  of the screen  12  of  FIG. 1  to make an undesired move in reverse of the direction the captive disc  26  was moved. 
     To prevent such undesired reverse movement, the border area  25   b  can have a distinctive pattern which may be detected by the sensor  24  or by external electronics  46  such that, when portions of the border area  25   b  is viewed by the sensor  24  during the return movement, motion reporting is suppressed for an appropriate period of time, movement distance, or both. Thus the undesired reverse movement is suppressed. Alternatively, or in combination, to suppressing the reporting of the undesired reverse movement, the border area  25   b  pattern may be designed such that the image becomes defocused above focal plane  26   c  thereby suppressing motion detection during the return movement. The suppression method, the defocus method, or both can be implemented as firmware within the sensor  24 , the circuits and electronics  46 , or both. The border area  25   b  is a circular area (for a circular disc) and can define the area outside the navigation area  25   a  to the edge of the disc  26 . 
     The apparatus  10  of  FIG. 1  can be configured such that a single translation of the captive disc  26  from center to its extent does not move the icon  14  of  FIG. 1  across the entire screen  12  of  FIG. 1 . This is accomplished using the suppression method, the defocus method, or both as discussed above. The user can lift the finger and continue the icon  14  along the desired path by translating the surface again. The return movement is analogous to “skating” of a traditional computer mouse where, upon reaching an edge of a mouse pad, the user lifts the mouse off from the mouse pad surface, translates the mouse closer to the center of the mouse pad, and lowers the mouse onto the mouse pad to allow further movement of the mouse. Alternatively, the apparatus  10  can be designed such that a single translation of the captive disc  26  causes the icon  14  to travel across the entire screen  12 . 
     An alternative embodiment of the input device  60  having an alternative embodiment of the captive disc is illustrated in  FIG. 3 . Portions of the input device  60  are similar to corresponding portions of the input device  20  of  FIGS. 2A through 2E . For convenience, portions in  FIG. 3  that are similar to portions in  FIG. 2A through 2E  are assigned the same reference numerals and different portions are assigned different reference numerals. Further, to avoid clutter, not all elements of the input device  20  of  FIGS. 2A through 2E  are illustrated in  FIG. 3 ; however, the input device  60  has at least all of the components illustrated in  FIGS. 2A through 2E . 
     Referring to  FIG. 3 , the input device  60  includes a convex shaped captive disc  62  rather than a substantially flat captive disc  26  of  FIGS. 2A  through  2 E. In this alternative embodiment, when the convex captive disc  62  is pressed down to or proximal to the focal plane (for example, position illustrated by the captive discs  26   b  and  26   c  of  FIG. 2C ), its active surface  63  comes into focal view of the sensor  24  at the focal area  44 . When the convex captive disc  62  is moved to a horizontal limit position (for example, position illustrated by the captive disc  26   d  of  FIG. 2E ), convex portion  66  of the convex captive disc  62  is at the focal area  44  of the sensor  24 . Because of the convex shape, the convex portion  66  of the active surface  63  is out of focal plane (thus, out of focus) of the sensor  24 . Thus, during return movements of the convex captive disc  62 , no area of the active surface  63  is in focus of the sensor  24 . Accordingly, it is not necessary for the active surface  63  to have a border area such as the border area  25   b  of active surface  25  as illustrated in  FIG. 2D . 
     Furthermore, in  FIG. 3 , the sensor  24  is illustrated outside the frame  32 . This is an alternative location of the sensor  24  compared to the location of the sensor in  FIGS. 2A through 2E . In this case, the sensor views the active surface  63  through a sensor opening  65 . In another alternative embodiment, a concave shaped captive disc can similarly be used. 
     From the foregoing, it will be appreciated that the present invention is novel and offers advantages over the current art. Although a specific embodiment of the invention is described and illustrated above, the invention is not to be limited to the specific forms or arrangements of parts so described and illustrated. For example, the captive disc  26  of  FIGS. 2A through 2E  is illustrated as a circular disc; however, the present invention is not so limited. The captive disc  26  can have other forms and shapes such as triangular, rectangular, or polygon shape. The invention is limited by the claims that follow.