Variable speed tactile switch

• US 5,550,339 A
• Filed: 10/31/1994
• Issued: 08/27/1996
• Est. Priority Date: 10/31/1994
• Status: Expired due to Term

• Current Assignee: Minebea Company Limited (MinebeaMitsumi Inc.)
• Original Assignee: CTS Corporation
• Inventors: Haugh, James E.
• Primary Examiner(s): Scott, J. R.
• Application Number:
  US08/331,422
• Time in Patent Office: 666 Days
• Field of Search: 200/85 R, 200/86 R, 200/512-517, 200/5 A, 200/6 A, 178/18, 178/19, 338/99, 338/114
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 2221/012 Joy stick type
• CPC Class Codes: H01H 2239/078 Variable resistance by variable contact area or point

Abstract

A low cost, highly sensitive tactile pointing device includes a planar substrate, an insulating spacer about a periphery of the substrate, and a planar cover. The cover in an active area carries an electrically conductive film designed to contact a conductive film carried upon an active area of the substrate. An insulating spacer and conductive dot are also located at some point within the active area to form a non-contacting rest area. Appropriate forces applied in a direction normal to the plane of the substrate or cover cause deflection, leading to contact between the cover and the substrate. The point of contact identifies intent, direction and magnitude.

Claims

1. A sensor for sensing intent, direction and magnitude comprising:

first and second contact members extending in planes parallel to but spaced from each other, said first contact member being flexible and resilient so as to deform upon the application of a force normal to said first contact member;

first and second means for conducting electricity, said first conducting means deforming with said first contact member upon said application of said normal force, said first conducting means and said first contact member further being sufficiently flexible as to permit said first conducting means to make electrical contact with said second conducting means when said normal force reaches a sufficient magnitude, said first conducting means and said first contact member further being sufficiently resilient as to substantially return to an initial shape prior to an application of said normal force of said sufficient magnitude;

a first electrically insulating means for spacing said first and second contact members a predetermined distance apart, said first electrically insulating means positioned apart from an active area formed by areas of possible contact between said first and second conducting means;

a second electrically insulating means for spacing said first and second contact members a predetermined distance apart, said second electrically insulating means positioned within an active area formed by areas of possible contact between said first and second conducting means to thereby define a region of non-contact within said active area;

an electrical circuit formed by said first conducting means and said second conducting means and further including a first termination and a second termination, said electrical circuit having a nearly infinite resistance between said first and said second termination indicative of an open circuit when no normal force is applied to said first contact member, said nearly infinite resistance to thereby signal a lack of intent, said electrical circuit having a finite and determinable resistance during said application of said normal force at a first location within said active area and outside of said region of non-contact within said active area, said finite and determinable resistance varying as a function of a distance between said region of non-contact and said first location, wherein said finite and determinable resistance thereby signals an intent and a magnitude and direction of said intent.

2. The sensor of claim 1 wherein said first means for conducting electricity is integral to said first contact member.

3. The sensor of claim 1 wherein said first means for conducting electricity is a film formed upon said first contact member.

4. The sensor of claim 1 wherein said first electrically insulating spacing means defines a periphery of said active area, and said second electrically insulating spacing means is located within said periphery of said active area and is physically separate from said first electrically insulating spacing means.

5. The sensor of claim 1 further comprising a third termination means, said first termination means directly connected to said first conducting means, said second conducting means electrically connected to said second and said third termination means, said second and said third termination means defining a sense axis along said second conducting means.

6. The sensor of claim 5 further comprising a region of relatively greater electrical conductivity than the balance of said second conducting means, said region of greater conductivity located between said second and said third terminations.

7. The sensor of claim 5 wherein said region of greater conductivity is located within said region of non-contact within said active area.

8. The sensor of claim 1 wherein said region of greater conductivity and said region of non-contact within said active area are centered between said second and said third terminations.

11. The sensor of claim 1 wherein said region of non-contact maintains non-contact independent of a human finger applying a normal force thereto.

9. A variable speed tactile switch comprising:

an electrically non-conductive substrate;

a first electrically conductive film patterned upon said substrate and having a second relatively more electrically conductive film patterned at a localized region upon said first electrically conductive film, said first electrically conductive film electrically terminated at a first termination and a second termination;

a first electrically non-conductive spacer outlining an active region within said first electrically conductive film;

a second electrically non-conductive spacer outlining a tactile region of non-contact within said active region which includes a majority of said relatively more conductive localized region upon said first electrically conductive film;

an electrically non-conductive flexible and resilient cover;

a third electrically conductive film patterned upon said cover, said third conductive film adjacent to said second electrically non-conductive spacer and an air space between said third conductive film and said first conductive film, said third conductive film electrically terminated at a third termination,

said first, second and third electrically conductive films forming a variable resistance switch, said switch actuatable by a cover deforming force which electrically connects said first and said third conductive films, a location of said force which determines an amount of resistance of said variable resistance switch.

10. The variable speed tactile sensor of claim 9 further comprising an optic source transilluminating said variable speed tactile sensor so as to be visibly illuminated through said cover, said optic source emitting visible radiation from a point within or adjacent said relatively more conductive localized region.