Resistance type sensor

• US 7,064,561 B2
• Filed: 07/03/2003
• Issued: 06/20/2006
• Est. Priority Date: 07/05/2002
• Status: Expired due to Fees

• Current Assignee: Nitta Corporation
• Original Assignee: Nitta Corporation
• Inventors: Morimoto, Hideo
• Primary Examiner(s): DEB, ANJAN K
• Application Number:
  US10/613,745
• Publication Number:
  US 20040056669A1
• Time in Patent Office: 1,083 Days
• Field of Search: 324/691, 324/722, 324/724, 324/716, 738/624.73, 738/624.74, 338/47, 847/23, 178/18.05, 345/174, 200/512
• US Class Current: 324/691
• 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: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3271 Power saving in keyboard
• CPC Class Codes: G06F 11/3062 where the monitored property is the power consumption power management in a computing system G06F1/3203
• CPC Class Codes: G06F 11/3093 Configuration details thereof, e.g. installation, enabling, spatial arrangement of the probes
• CPC Class Codes: G06F 3/0338 with detection of limited linear or angular displacement of an operating part of the device from a neutral position, e.g. isotonic or isometric joysticks
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

In a resistance type sensor of the present invention, a sensor unit having variable contact resistances and a wakeup switch formed in two layers is produced by folding a FPC forming thereon pressure-sensitive resistive inks, a displacement electrode connected to ground, and a displacement electrode held at a power-supply voltage Vcc. Accordingly, whenever operation is applied to an operating button, the displacement electrode and the displacement electrode are reliably contacted with each other, first, and, then, resistance values of the variable contact resistances are changed while the displacement electrodes are kept in their contacted state. This enables the operation applied to the operating button to be detected reliably.

Claims

1. A resistance type sensor comprising:

a detective member;

a first electrode facing the detective member;

a second electrode disposed between the detective member and the first electrode and facing the first electrode, wherein the second electrode is displaceable toward the first electrode in accordance with displacement of the detective member;

a pressure-sensitive resistive member disposed between the first electrode and the second electrode;

at least one first switching electrode disposed between the detective member and the second electrode and facing the detective member; and

at least one second switching electrode disposed between the detective member and the first switching electrode, wherein the second switching electrode comes into contact with the first switching electrode in accordance with displacement of the detective member, and

wherein the displacement of the detective member is identified on the basis of a detection of a change in resistance between the first electrode and the second electrode.

2. The resistance type sensor according to claim 1, further comprising:

a first substrate mounting the first electrode thereon;

a second substrate mounting the second electrode thereon;

a first switching substrate mounting the first switching electrode thereon; and

a second switching substrate mounting the second switching electrode thereon.

3. The resistance type sensor according to claim 2, wherein the first substrate, the second substrate, the first switching substrate, and the second switching substrate are formed by a single common substrate having flexibility.

4. The resistance type sensor according to claim 3, wherein the first electrode, the second electrode, the first switching electrode, and the second switching electrode are all arranged on one side of the common substrate.

5. The resistance type sensor according to claim 2, wherein the first switching electrode and the second switching electrode are disposed so as to overlap with the first electrode and the second electrode with respect to a displacement direction of the detective member.

6. The resistance type sensor according to claim 1, wherein the first switching electrode and the second switching electrode are disposed so as to overlap with the first electrode and the second electrode with respect to a displacement direction of the detective member.

7. The capacitance type sensor according to claim 1, wherein the first switching electrode and the second switching electrode are disposed to be closer to the detective member than the first electrode and the second electrode.

8. The resistance type sensor according to claim 7, wherein one of the first switching electrode and the second switching electrode is connected to ground and the other of the first switching electrode and the second switching electrode are held at different potential from ground potential, and wherein the first switching electrode and the second switching electrode come into contact with each other in accordance with the displacement of the detective member, whereby second electrode is displaced.

9. The resistance type sensor according to claim 1, wherein there are provided a plurality of pairs of the first electrodes and the second electrodes.

10. The resistance type sensor according to claim 1, wherein there are provided a plurality of pairs of the first switching electrodes and the second switching electrodes.