Capacitance type sensor and method for manufacturing same

• US 6,958,614 B2
• Filed: 05/28/2003
• Issued: 10/25/2005
• Est. Priority Date: 05/29/2002
• Status: Expired due to Fees

• Current Assignee: Nitta Corporation
• Original Assignee: Nitta Corporation
• Inventors: Morimoto, Hideo
• Primary Examiner(s): Deb, Anjan
• Assistant Examiner(s): Natalini, Jeff
• Application Number:
  US10/446,554
• Publication Number:
  US 20030222660A1
• Time in Patent Office: 881 Days
• Field of Search: 324/658, 324/659, 324/660, 324/661, 324/662, 324/686, 738/640.43, 737/80, 735/143.2
• US Class Current: 324/661
• CPC Class Codes: G01L 1/142 using capacitors
• CPC Class Codes: G01L 1/144 with associated circuitry G01L1/146 and G01L1/148 take precedence
• CPC Class Codes: G01L 5/165 using variations in capacitance
• CPC Class Codes: G01L 5/223 to joystick controls
• CPC Class Codes: G01L 9/0072 using variations in capacitance
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: H01H 2025/048 having a separate central push, slide or tumbler button which is not integral with the operating part that surrounds it
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H01H 2300/022 Application wake up; switches or contacts specially provided for the wake up or standby shift of a circuit
• CPC Class Codes: H01H 25/041 having a generally flat operating member depressible at different locations to operate different controls
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49005 Acoustic transducer
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49103 Strain gauge making

Abstract

In a capacitance type sensor of the present invention, a capacitance element is constituted between a displacement electrode and a capacitance element electrode. A return-switch movable electrode is arranged above and spaced from the displacement electrode, to be placed in contact with the displaying electrode due to a displacement of a direction button. When the direction button is operated, the return-switch movable electrode is first displaced into contact with the displacement electrode. Then, the both make a displacement while keeping a contact state. When the displacement electrode is displaced to change the spacing to the capacitance element electrode, changed is the capacitance value of the capacitance element. Based on this change, a force is recognized. Herein, in the course of a transit from a state the displacement electrode and the return-switch electrode are not in contact to a state of their contact, the output signal varies necessarily beyond a threshold voltage.

Claims

1. A capacitance type sensor comprising:

a conductive member;

a capacitance element electrode constituting a capacitance element with the conductive member; and

at least one movable electrode disposed on the side opposite to the capacitance element electrode at a distance from the conductive member, wherein, when a force is applied to the movable electrode, the movable electrode moves so as to come into contact with and displace the conductive member, and

wherein the force applied to the movable electrode is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

2. The capacitance type sensor according to claim 1, wherein the movable electrode and the conductive member are formed of a conductive film, and the conductive member is formed with a hole.

3. The capacitance type sensor according to claim 2, further comprising a mechanism for deforming into concavo-convex the movable electrode and the conductive member in a region not facing the capacitance element electrode so as to apply a tensile force thereto.

4. A capacitance type sensor comprising:

a substrate;

a detective member facing the substrate;

a conductive member disposed between the substrate and the detective member and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate;

a capacitance element electrode disposed on the substrate and constituting a capacitance element with the conductive member;

at least one fixed electrode disposed on the substrate; and

at least one movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the fixed electrode, wherein the movable electrode moves so as to comes into contact with and displace the conductive member, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

5. A capacitance type sensor comprising:

a substrate;

a detective member facing the substrate;

a conductive member disposed between the substrate and the detective member and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate;

a capacitance element electrode disposed on the substrate and constituting a capacitance element with the conductive member;

a reference electrode disposed on the substrate and electrically connected to the conductive member and grounded;

a fixed electrode disposed on the substrate and kept at a different potential from a ground potential; and

a movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the fixed electrode, wherein the movable electrode moves so as to come into contact with and displace the conductive member, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance value of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

6. A capacitance type sensor comprising:

a substrate;

a detective member facing the substrate;

a conductive member disposed between the substrate and the detective member and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate;

a capacitance element electrode formed on the substrate and constituting a capacitance element with the conductive member;

a reference electrode formed on the substrate and electrically connected to the conductive member, and kept at a different potential from a ground potential;

a fixed electrode formed on the substrate and grounded; and

a movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the fixed electrode, wherein the movable electrode moves so as to come into contact with and displace the conductive member, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

7. A capacitance type sensor comprising:

a substrate;

a detective member facing the substrate;

a conductive member disposed between the substrate and the detective member and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate, wherein the conductive member is in electrically insulated;

a capacitance element electrode formed on the substrate and constituting a capacitance element with the conductive member;

a fixed electrode formed on the substrate and grounded; and

a movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the fixed electrode, wherein the movable electrode moves so as to come into contact with and displace the conductive member, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

8. A capacitance type sensor comprising:

a substrate;

a detective member facing the substrate;

a conductive member disposed between the substrate and the detective member and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate, wherein the conductive member is electrically insulated;

a capacitance element electrode formed on the substrate and constituting a capacitance element with the conductive member;

a first fixed electrode formed on the substrate;

a second fixed electrode formed on the substrate;

a first movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the first fixed electrode; and

a second movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, and electrically connected to the second fixed electrode,

wherein the first fixed electrode is grounded and the second fixed electrode is kept at a different potential from a ground potential, and the first and second movable electrodes move so as to come into contact with and displace the conductive member, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode.

9. A capacitance type sensor comprising:

a detective member;

a substrate facing the detective member;

a conductive member disposed between the detective member and the substrate and displaceable in a displacement direction of the detective member as the detective member is displaced in a direction normal to the substrate;

a capacitance element electrode formed on the substrate and constituting a capacitance element with the conductive member;

at least one movable electrode disposed between the detective member and the conductive member at a distance from the conductive member, wherein the movable electrode moves so as to come into contact with and displace the conductive member;

a switch substrate;

a first switch electrode formed on the switch substrate; and

a second switch electrode kept at a predetermined potential and disposed at a distance from the first switch electrode, wherein the second switch electrode moves so as to come into contact with the first switch electrode, and

wherein the displacement of the detective member is identified on the basis of a detection, using a signal input to the capacitance element electrode, of a change in capacitance of the capacitance element caused by a change in distance between the conductive member and the capacitance element electrode, and whether or not the first and the second switch electrodes are in contact with each other is judged, by using a signal input to the first switch electrode.