Touch controlled membrane for multi axis voltage selection

• US 4,444,998 A
• Filed: 10/27/1981
• Issued: 04/24/1984
• Est. Priority Date: 10/27/1981
• Status: Expired due to Term

• Current Assignee: Spectra Symbol Corp. (Zebra Technologies Corporation)
• Original Assignee: Spectra Symbol Corp. (Zebra Technologies Corporation)
• Inventors: House, V. Dean
• Primary Examiner(s): SCHREYER, STAFFORD
• Application Number:
  US06/315,374
• Time in Patent Office: 910 Days
• Field of Search: 178/19, 178/18, 178/20, 338/114, 338/205
• US Class Current: 178/18.05
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A touch controlled membrane device producing an output signal which is a function of any dual coordinate location resulting from an applied pressure in a two dimensional resistive field. In one preferred embodiment a single resistive film is spaced from a coextensive conductive film. First and second source voltages are alternately applied across orthogonal axis directions of the resistive film to establish voltage gradients in both directions. Pressure applied to the conductive film brings the conductive and resistive films into contact so that a unique two component output signal appears on the conductive film which defines the X and Y coordinates of the location of the applied pressure. In a second embodiment, two resistive films are mounted opposite to two conductive surfaces applied onto opposite sides of an insulative film, and voltage is applied to the resistive films in orthogonally related directions. Pressure applied to one resistive film causes both resistive films to contact the conductive surfaces so that the voltages applied to each conductive surface represent the coordinates of the point of contact.

Claims

1. A touch controlled membrane device for providing output signals representative of any dual coordinate position resulting from an applied pressure in a two dimensional field, said device comprising:

a first member having an electrically resistive surface;

a second member having an electrically resistive surface;

a third member having first and second conductive surfaces;

means for supporting said first and second members in close spaced and substantially coextensive relationship to said third member such that contact between the first conductive surface and first resistive surface and between the second conductive surface and second resistive surface will occur in response to application of localized pressure to at least one of said first and second members at any point in said field;

means for applying a first voltage across said first member;

a means for applying a second voltage across said second member in a direction substantially orthogonal to that of the first voltage;

a first output circuit for providing a first output voltage corresponding to the point of contact between said first resistive and conductive surfaces; and

a second output circuit for providing a second output voltage corresponding to the point of contact between said second resistive and conductive surfaces.

2. A device as defined in claim 1 wherein said first and second members are flexible so as to be responsive to the said applied pressure.

3. A touch controlled membrane for defining any dual coordinate position in a two dimensional field producted by any point of applied pressure in said two dimensional field, the device comprising:

a first resistive member for establishing a continuous voltage gradient in a first axis direction in response to application of a first voltage thereto;

a second resistive member for establishing a continuous voltage gradient in a second axis direction in response to application of a second voltage thereto;

means for applying said first voltage to said first resistive member;

means for applying said second voltage to said second resistive member; and

conductive means for contacting said first and second resistive members at said point of applied pressure so as to provide output voltages corresponding to the voltages appearing at the points of contact of said conductive means with said first and second resistive members.

4. A device as defined in claim 3 wherein said conductive means comprises first and second conductive surfaces positioned substantially coextensive with and in close spaced relation to said first and second resistive members, respectively.

5. A device as defined in claim 4 wherein said conductive means comprises an insulative film having opposite surfaces which provide said first and second conductive surfaces.

6. A device as defined in claim 3 wherein said first and second members comprise resistive films.

7. A device for defining any dual coordinate position produced by an applied pressure in a two dimensional resistive field, said device comprising:

a first member having a resistive surface;

a second member having a first conductive surface mounted in closely spaced, substantially coextensive relationship with the resistive surface of said first member;

a third member having a resistive surface;

a second conductive surface on said second member mounted in closely spaced, substantially coextensive relationship with the resistive surface of said third member;

a first pair of terminals secured to the resistive surface of said first member and responsive to application of voltage thereto for establishing a voltage gradient in a first axis direction;

a second pair of terminals secured to the resistive surface of said third member and responsive to application of voltage thereto for establishing a voltage gradient in a second axis direction which is substantially orthogonal with respect to said first direction; and

means for outputting the voltage applied to each said conductive surface during contact with the respective resistive surfaces.

8. A touch controlled membrane device for defining any dual coordinate position in a two dimensional resistive field produced by an applied pressure, the device comprising:

a first member having a first electrically resistive surface for establishing a continuous voltage gradient in a first direction in said two dimensional resistive field in response to application of a first voltage thereto;

a second member having a second electrically resistive surface for establishing a continuous voltage gradient in a second direction in said two dimensional resistive field in response to application of a second voltage thereto;

means for providing a power source for generating said first and second voltages applied to said resistive field; and

a third member having first and second conductive surfaces positioned substantially coextensive with and in close spaced relation to said first and second resistive surfaces, respectively, for providing first and second output voltages corresponding to any point of contact on said resistive field resulting from the applied pressure.

9. A device as defined in claim 8 wherein said third member comprises an insulative film having opposite sides thereof which provide said first and second conductive surfaces.

10. A device as defined in claim 8 wherein said first and second members comprise resistive films.