Pressure-sensitive resistor

• US 5,948,990 A
• Filed: 08/25/1997
• Issued: 09/07/1999
• Est. Priority Date: 09/04/1996
• Status: Expired due to Term

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Hashida, Junji
• Primary Examiner(s): Patel, Harshad
• Assistant Examiner(s): CLARK, ROBIN C
• Application Number:
  US08/918,035
• Time in Patent Office: 743 Days
• Field of Search: 73/725, 73/726, 73/728, 73/720, 73/719, 73/779, 73/862.01, 73/862.04, 73/862.55, 73/862.66, 73/862.68, 338/2, 338/3, 338/4, 338/5, 338/7, 338/36, 338/37, 338/38-47, 338/13, 338/71, 338/99, 338/114
• US Class Current: 73/725
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01L 1/205 using distributed sensing elements
• CPC Class Codes: H01C 10/10 adjustable by mechanical pressure or force

Abstract

The present invention relates to a pressure-sensitive resistor in which the resistance between two electrode patterns varies in response to applied pressure, wherein the desired pressure-sensitive characteristics of the resistor can be readily achieved by appropriately adjusting the degree of the planar-positional difference between the two electrode patterns. This pressure-sensitive resistor comprises two insulating substrates, each one of which has an opposing surface facing the other substrate, and at least one of which is flexible; and at least one pressure-sensitive module which comprises a pressure-sensitive conductor disposed between said insulating substrates and having a predetermined electrical resistance in directions along the surfaces of said insulating substrates, and two electrode patterns situated between at least one of said insulating substrates and said pressure-sensitive conductor, wherein said two electrode patterns are formed on at least one of the opposing surfaces of said two insulating substrates so as not to overlap with each other in plan view. When this pressure-sensitive resistor is pressed, the contact resistances between the electrode patterns and the pressure-sensitive conductor is altered in accordance with the applied pressing force.

Claims

1. A pressure-sensitive resistor comprising:

two insulating substrates, each of which has an opposing surface facing the other substrate, and at least one of which is flexible;

at least one pressure-sensitive module which comprises a pressure-sensitive conductor disposed between said insulating substrates and having a predetermined electrical resistance in directions along the surfaces of said insulating substrates, and two electrode patterns situated between at least one of said insulating substrates and said pressure-sensitive conductor,

wherein said two electrode patterns are formed on at least one of the opposing surfaces of said two insulating substrates so as not to overlap with each other in plan view, and said two electrode patterns are formed on the opposing surfaces of said insulating substrates one by one; and

wherein said pressure-sensitive conductor is formed on at least one of said two insulating substrates where said electrode patterns are formed, said pressure-sensitive conductor comprises a base conductive film and insulating particles projecting from the film; and

said pressure-sensitive conductor comprises a conductive film formed by mixing carbon in a binder and insulating particles protecting from the conductive film.

2. The pressure-sensitive resistor according to claim 1, wherein the diameters of said insulating particles are larger than the thickness of said conductive film where the insulating particles are embedded.

3. A pressure-sensitive resistor comprising:

two insulating substrates, each of which has an opposing surface facing the other substrate, and at least one of which is flexible;

at least one pressure-sensitive module which comprises a pressure-sensitive conductor disposed between said insulating substrates and having a predetermined electrical resistance in directions along the surface of said insulating substrates, and two electrode patterns situated between at least one of said insulating substrates and said pressure-sensitive conductor,

wherein said two electrode patterns are formed on at least one of the opposing surfaces of said two insulating substrates so as not to overlap with each other in plan view;

said two electrode patterns are formed on the opposing surfaces of one of said two insulating substrates;

said pressure-sensitive conductor is formed on the opposing surface of the other insulating substrate; and

said pressure-sensitive conductor comprises a conductive film formed by mixing carbon in a binder and insulating particles projecting from the film.

4. The pressure-sensitive resistor according to claim 3, wherein the diameters of said insulating particles are larger than the thickness of said conductive film where the insulating particles are embedded.

5. The pressure-sensitive resistor according to claim 4, wherein said conductive film is formed by printing using a conductive ink in which insulating particles are dispersed.

6. The pressure-sensitive resistor according to claim 3, wherein each of said two electrode patterns comprises a conductive film and insulating particles projecting from the surface of the film.

7. The pressure-sensitive resistor according to claim 3, wherein said two electrode patterns are simultaneously formed on one of the opposing surfaces of said insulating substrates by printing.

8. The pressure-sensitive resistor according to claim 3, wherein said two insulating substrates are laminated with the intervention of a spacer such that said two electrode patterns oppose said pressure-sensitive conductor at an interval.

9. The pressure-sensitive resistor according to claim 8, wherein said pressure-sensitive resistor has a plurality of dispersively disposed pressure-sensitive modules each comprising said two electrode patterns, and said pressure-sensitive conductor opposing them.

10. A pressure-sensitive resistor comprising:

two insulating substrates, each of which has an opposing surface facing the other substrate, and at least one of which is flexible;

at least one pressure-sensitive module which comprises a resistor member disposed between said insulating substrates, and two electrode patterns formed on one of the opposing surfaces of said two insulating substrates so as not to overlap with each other in plan view;

wherein each of said electrode patterns comprises a base conductive film and insulating particles projecting from the film; and

wherein each of said conductive films is formed by printing using a conductive ink in which insulating particles are dispersed.

11. The pressure-sensitive resistor according to claim 10, wherein the diameters of the insulating particles are larger than the thickness of the conductive film where said insulating particles are embedded.