Abstract:
A joystick with improved performance, reliability and durability, that can be used as a cursor pointing device for computers, remote controls, web TV, TV guide browsers, VCR&#39;s video games, consumer electronics, industrial controllers, medical, automotive and other applications. An uninterrupted conductive curved elastomeric transducer can be deflected to positions on an electrical medium that results in the generation of a speed and direction signal to be interpreted by low cost available circuitry including microcontroller.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates in general to joystick pointing devices and in particular to an improved pointing device. 
     2. Description of Related Art 
     Joysticks are known in the art such as shown by DeVolpi U.S. Pat No. 5,675,309 entitled “Curved Disc Joystick Pointing Device”, and copending CIP application thereof, Ser. No. 08/496,433, filed Oct. 6, 1997. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of my invention are that the uninterrupted curved disc pointing device can be assembled in mass production at a consistent quality and uniformity. Second, the amount of force needed to deflect is also reduced greatly giving increased user controllability as well as the added increased active PCB surface area for greater or maximum resolution. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and accompanying drawings. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an improved joystick pointing device that has the advantage of lower cost, higher reliability, and quicker and more accurate response with fewer parts. 
     The present invention comprises a pointing device with a combination of conductive contacts and resistive contacts on the substrate that cover the maximum surface area that the disc makes contact with when the disc has an external force applied. The disc will pivot and act like a movable fulcrum point. 
     Another feature of the present invention is to reduce the number of components that are a bottleneck for mass production and allow for production by automated machinery with high quality. 
     Other objects, features and advantages will be readily apparent from the following description of certain preferred embodiments thereof taken in conjunction with the accompanying drawings although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of my invention with a plastic cap inserted for rigidity. 
     FIG. 2 is a cross section view of my invention including a plastic cap. 
     FIG. 3 is a detail of the top side of the PCB. 
     FIG. 4 is a detail view of the bottom of the PCB. 
     FIG. 5 is a perspective view of my invention with pull through tabs. 
     FIG. 6 is a cross section view of my invention with tabs that protrude through the PCB. 
     FIG. 7 is a view of the top side of the PCB with the tab pull through holes. 
     FIG. 8 is a view of the bottom of the PCB with holes for the pull through tab. 
     FIG. 9 is a perspective view of my invention without the rigid insert. 
     FIG. 10 is a cross section of the invention without the rigid insert. 
     FIG. 11 is a cross section of my invention with a conductive wire. 
     FIG. 12 is a cross section of my invention with a conductive spring. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The invention comprises a joystick pointing device which uses a board such as a printed circuit board, glass, paper, ceramic or plastics which have conductive lines and resistive coatings formed on it or embedded or likewise provided on the surface. The board does not have a hole for the spring to pivot in. The conductive disc is held in place by the rubber return mechanism. If the joystick has force applied the resultant force causes a tilting action on the solid disc. This conductive disc makes contact on the PCB in 360 degrees thereby making contact on different parts of the PCB where there are conductive/resistive tracts. The contact on the PCB produces a variable current thereby causing a RC timing constant that can be interpreted by a simple timing loop of a microcontroller. In turn the microcontroller can interpret this data and correspondingly cause an output in speed and direction. 
     FIG. 1 is a perspective view showing the elements of an assembled module  10  which consists of the following basic parts. The outside is made of non-conductive elastomer  12 . The non-conductive elastomer  12  has a mechanical return slope  14  built into it. The joystick  16  is also made with the non-conductive elastomer  12 . Underneath the nonconductive elastomer  12  is a rigid cap  18  that covers the electrically conductive contiguous uninterrupted curved disc  20  that rests above the top of the PCB  22 . A conductive leg  24  rests on the surface and makes electrical contact with the PCB  22 . 
     FIG. 2 shows a cross section view whereby the PCB  22  has an electrically conductive contiguous uninterrupted curved disc  20  on its surface and the electrically conductive contiguous uninterrupted curved disc  20  is held in place by the rigid cap  18  and the nonconductive elastomer  12  that has the mechanical return slope  14  built into it. The electrically conductive contiguous uninterrupted curved disc  20  has an electrically conductive leg  24  that makes contact on the surface of the PCB  22  thereby making electrical connection at contact area  30 . 
     FIG. 3 is the detail of the top of the PCB  22 . The PCB  22  has highly conductive traces  26  that surround the center as well as resistive elements  28  that connect the highly conductive traces  26 . There is at least one contact area  30  on the PCB  22  where the electrically conductive leg  24  makes electrical contact with the PCB  22 . The PCB  22  has vias  32  that electrically connect the top and bottom of the PCB  22 . 
     FIG. 4 is the detail of the bottom of the PCB  22  whereby the vias  32  have various highly conductive traces  26  to pass the variable electrical signal on without degrading the signal. 
     FIG. 5 is a perspective view showing the elements of an assembled module  10  which consists of the following basic parts. The outside is made of non-conductive elastomer  12 . The non-conductive elastomer  12  has a mechanical return slope  14  built into it. The joystick  16  is also made with the non-conductive elastomer  12 . Underneath the nonconductive elastomer  12  is a rigid cap  18  that covers the electrically conductive contiguous uninterrupted curved disc  20  that rests above the top of the PCB  22 . There is a pull through tab  34  that is attached to the electrically conductive leg  24  of the electrically conductive contiguous uninterrupted curved disc  20  to provide electrical connection to the contact area  30  of the PCB  22 . 
     FIG. 6 shows a cross section view whereby the PCB  22  has an electrically conductive contiguous uninterrupted curved disc  20  on its surface and the electrically conductive contiguous uninterrupted curved disc  20  is held in place by the rigid cap  18  and the nonconductive elastomer  12  that has the mechanical return slope  14  built into it. The electrically conductive contiguous uninterrupted curved disc  20  has an electrically conductive leg  24  and a pull through tab  34  that makes contact on the surface of the PCB  22  thereby making electrical connection. 
     FIG. 7 is the detail of the top of the PCB  22 . The PCB  22  has highly conductive traces  26  that surround the center as well as resistive elements  28  that connect the highly conductive traces  26 . There is at least one contact area  30  on the PCB  22  where the electrically conductive leg  24  makes electrical contact with the PCB  22 . The PCB  22  has vias  32  that electrically connect the top and bottom of the PCB  22 . There are holes  40  in the PCB  22  for the pull through tab  34  to be pulled through. 
     FIG. 8 is the detail of the bottom of the PCB  22  whereby the vias  32  have various highly conductive traces  26  to pass the variable electrical signal on without degrading the signal. There are also larger holes  40  in the PCB  22  for the pull through tab  34  to be pulled through. 
     FIG. 9 is a perspective view showing the elements of an assembled module  10  which consists of the following basic parts. The outside is made of non-conductive elastomer  12 . The non-conductive elastomer  12  has a mechanical return slope  14  built into it. The joystick  16  is also made with the non-conductive elastomer  12 . Underneath the nonconductive elastomer  12  is an electrically conductive contiguous uninterrupted curved disc  20  that rests above the top of the PCB  22 . 
     FIG. 10 shows a cross section view whereby the PCB  22  has an electrically conductive contiguous uninterrupted curved disc  20  on its surface and the electrically conductive contiguous uninterrupted curved disc  20  is held in place by the non-conductive elastomer  12  that has the mechanical return slope  14  built into it. The electrically conductive contiguous uninterrupted curved disc  20  has an electrically conductive leg  24  that makes contact on the surface of the PCB  22  thereby making electrical connection. 
     The assembled module  10  is in a static position when no external forces are applied. In the static or in a non static position the leg electrically conductive leg  24  makes contact with the PCB  22  at the contact area  30 . The result of the contact is that the electrically conductive contiguous uninterrupted curved disc  20  is always electrically active all over the continuous surface of the electrically conductive contiguous uninterrupted curved disc  20 . When an external force is applied to the joystick  16  through the non-conductive elastomer  12  a resultant force causes a displacement of the mechanical return slope  14  through the joystick  16  directly. As the mechanical return slope  14  changes this kinetic energy into potential energy the electrically conductive contiguous uninterrupted curved disc  20  is pivoting on the PCB  22  which in turn changes the path of the electrical signal on the resistive elements  28  and the highly conductive traces  26 . This signal is sent to external circuitry through the vias  32  and pull through tab  34  from the contact area  30  touching the electrically conductive leg  24 . This signal is interpreted using any available A/D or RC timing circuit into direction and speed vectors. 
     Upon removing the force applied the potential energy stored in the mechanical return slope  14  causes the joystick  16  to return to its undeflected position. 
     CONCLUSIONS, RAMIFICATIONS, AND SCOPE 
     Accordingly, it can be seen that use of electrically conductive contiguous uninterrupted curved disc  20  without using a spring or protrusion in the center has the advantage of greater active surface area, fewer parts that translates into higher reliability, greater accuracy and lower costs. 
     Although the description above contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Various other embodiments and ramifications are possible within it&#39;s scope. For example, there are several PCB layouts of highly conductive traces  26  and resistive elements  28  that can be used as well as several methods of making the electrically conductive contiguous uninterrupted curved disc  20  become a current source such as connecting a wire  36  (FIG. 11) or a spring  38  (FIG. 12) to it instead of having an electrically conductive leg  24 , as well as several mechanical return slope  14  configurations not shown but are obvious. 
     Thus the scope of the invention should be determined by the appended claims and their legal equivalents, rather than by the examples given.