Capacitance type sensor

• US 7,391,411 B2
• Filed: 07/01/2005
• Issued: 06/24/2008
• Est. Priority Date: 02/08/2000
• Status: Expired due to Fees

• Current Assignee: Nitta Corporation, Wacoh Company
• Original Assignee: Nitta Corporation, Wacoh Company
• Inventors: Okada, Kazuhiro, Morimoto, Hideo
• Primary Examiner(s): Hjerpe; Richard A.
• Assistant Examiner(s): Said; Mansour M.
• Application Number:
  US11/173,407
• Publication Number:
  US 20050243064A1
• Time in Patent Office: 1,089 Days
• Field of Search: 345156-163, 345173-174, 341 20- 23, 200/6.A, 200/5.R, 463 36- 38, 178/18.01, 178/18.03, 178/18.05, 178/18.06
• US Class Current: 345/161
• 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

Abstract

A capacitance type sensor includes a substrate, a group of electrodes fixed on an upper face of the substrate, a movable electrode plate having an electrode on its lower side and a gap between the group of fixed electrodes on the substrate and the electrode on the movable electrode plate. The gap is formed with a solder layer, a conductive elastomer layer, a conductive paint layer, or a conductive adhesive material layer provided on the substrate. The electrode on the movable electrode plate is made of conductive rubber plate or conductive elastomer plate.

Claims

1. A capacitance type sensor comprising:

a substrate;

a group of fixed electrodes provided on an upper face of said substrate;

a movable electrode plate with a lower flat face having an electrode on said lower flat face and a rubber elasticity; and

wherein

said substrate is provided with a solder layer having a thickness, said solder layer supports said movable electrode plate and said thickness of said solder layer provides a gap between said group of fixed electrodes on said substrate and said electrode on said movable electrode plate, and said elastic movable electrode plate deforms due to force or moment applied thereto and said gap changes accordingly so as to change capacitance thereabout, and

said solder layer comprises a first solder layer and a second solder layer, said first solder layer being provided to surround said group of fixed electrodes and said second solder layer being located at a center of said group of fixed electrodes.

2. The capacitance type sensor according to claim 1, wherein said movable electrode plate comprises a silicone rubber member with a lower flat face and one of a flat conductive rubber plate and a flat conductive elastomer plate functioning as electrode and fixed on said lower flat face of the silicone rubber member.

3. The capacitance type sensor according to claim 1, wherein said movable electrode plate comprises a silicone rubber member with a lower flat face and a conductive ink layer functioning as electrode and formed on said lower flat face of the silicone rubber member.

4. The capacitance type sensor according to claim 1, wherein said movable electrode plate is set at a ground voltage.

5. The capacitance type sensor according to claim 1, wherein said solder layer is provided on a contact land on the substrate, electrical connection between said movable electrode plate and said contact land through said solder makes an entirety of said movable electrode plate is set at a ground voltage.

6. The capacitance type sensor according to claim 1, wherein one of said first and second solder layers is one of ink or paint by silk printing.