Tactile sensor

• US 8,300,018 B2
• Filed: 09/05/2005
• Issued: 10/30/2012
• Est. Priority Date: 09/05/2005
• Status: Expired due to Fees

• Current Assignee: Ewsystem Company Limited
• Original Assignee: Ewsystem Company Limited
• Inventors: Morimoto, Kenichi
• Primary Examiner(s): Wang, Quan-Zhen
• Assistant Examiner(s): MA, CALVIN
• Application Number:
  US11/990,759
• Publication Number:
  US 20080271933A1
• Time in Patent Office: 2,612 Days
• Field of Search: 345/173, 345/156, 338/205, 338/247, 178/18.05
• US Class Current: 345/173
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: B25J 13/084 Tactile sensors in general G01L5/16, G01L5/22
• CPC Class Codes: G01L 5/162 of piezoresistors
• CPC Class Codes: G01L 5/228 using tactile array force sensors
• CPC Class Codes: G06F 3/045 using resistive elements, e.g. a single continuous surface or two parallel surfaces put in contact

Abstract

A tactile sensor for detecting a variation in pressing real-time. The tactile sensor is simple in structure, detects a variation in pressing by using reduced wires, has increased reliability and reduced cost, and can obtain information accurately. A sheet has, along its surface, resistors arranged in an X direction and Y direction, has a resistor in Z direction corresponding to the thickness direction of the sheet, and has a pressure sensitive resistor sheet (4) whose resistance in the Z direction varies according to pressing in the thickness direction. At least a pair of electrodes (9, 10, 11, 12) is placed in the periphery of the pressure sensitive sheet (4), and the electrodes conduct a current to at least either of the resistor in the X direction or the resistor in the Y direction. Also, at least a pair of conductors (5, 6) for conducting a current to the resistor in the Z direction is provided on the surface of the pressure sensitive sheet (4).

Claims

1. A tactile sensor, comprising:

a pressure sensitive sheet having a length in an x direction, a width in a y direction and a thickness in a z direction, the pressure sensitive sheet providing an electrical resistance;

at least one pair of electrode parts on a peripheral part of the pressure sensitive sheet for passing a current through the pressure sensitive sheet in at least one of the x direction and y direction; and

a pair of electrically conductive sheets provided on opposite surfaces in the thickness direction of the pressure sensitive sheet for passing a current between the pair of electrically conductive sheets through the pressure sensitive sheet only in the z direction, the electrically conductive sheets being on opposite sides of the pressure sensitive sheet;

wherein the pair of electrically conductive sheets are coextensive with the pressure sensitive sheet, wherein surfaces of the pair of electrically conductive sheets facing the pressure sensitive sheet have electrical conductivity, and

wherein the pressure sensitive sheet is sandwiched from both sides in the thickness direction by the pair of electrically conductive sheets for passing the current through the pair of electrically conductive sheets only in the z direction when any part inside the peripheral part of the pressure sensitive sheet is pressed.

2. The tactile sensor of claim 1, wherein the pair of electrically conductive sheets are insulated from one another in the absence of pressure and electrically connected through the pressure sensitive sheet when pressure is applied to the pressure sensitive sheet.

3. The tactile sensor of claim 1, wherein the at least one pair of electrode parts comprises electrodes in the pressure sensitive sheet.

4. The tactile sensor of claim 1, wherein the at least one pair of electrode parts are opposite each other in the x direction on the peripheral part of the pressure sensitive sheet for passing a current in the x direction, a first electrode part of the pair of electrode parts providing a plurality of electrodes apart from each other in the y direction, a second electrode part of the pair of electrode parts providing a plurality of electrodes apart from each other in the y direction.

5. The tactile sensor of claim 1, wherein the at least one pair of electrode parts are opposite each other in the y direction on the peripheral part of the pressure sensitive sheet for passing a current in the y direction, a first electrode part of the pair of electrode parts providing a plurality of electrodes apart from each other in the x direction, a second electrode part of the pair of electrode parts providing a plurality of electrodes apart from each other in the x direction.