Elastic sheet structure having an improved electrical continuity function, and printed circuit board structure

• US 6,812,424 B2
• Filed: 01/10/2003
• Issued: 11/02/2004
• Est. Priority Date: 01/11/2002
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Original Assignee: Kabushiki Kaisha Tokai RIKA Denki Seisakusho
• Inventors: Miyako, Mamoru
• Primary Examiner(s): LAM, CATHY FONG FONG
• Application Number:
  US10/339,298
• Publication Number:
  US 20030133278A1
• Time in Patent Office: 662 Days
• Field of Search: 200/243, 200/292, 200/341, 200/511, 200/519
• US Class Current: 200/511
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/80 characterised by the manner of cooperation of the contacts, e.g. with both contacts movable or with bounceless contacts
• CPC Class Codes: H01H 2201/008 Both contacts movable
• CPC Class Codes: H01H 2205/002 fixed to operating part
• CPC Class Codes: H01H 2209/03 elastomeric

Abstract

In an elastic sheet member of the present invention, a silicon rubber sheet is supported by a fixed member. A wire group functioning as contacts is disposed at either one of the silicon rubber sheet or the fixed member. In other words, electrical continuity paths, which were conventionally provided at a printed circuit board, are basically provided at the elastic sheet member which is formed of a non-conductive material. In accordance with the present invention, there is no need for the printed circuit board to cover a range at which all rubber contacts are disposed, as in conventional art. Accordingly, the printed circuit board can be made compact, space required for placement thereof can be reduced, and degrees of freedom in design are increased.

Claims

1. An elastic sheet structure having an electrical continuity function, comprising:

an elastic sheet member formed of a non-conductive material and formed in a sheet-shaped form, and having push portions which, when pushed, elastically deform and displace movable contacts, which are provided at reverse surface sides of the push portions, in a direction of pushing by a predetermined distance so as to make the movable contacts electrically continuous with fixed contacts; and

continuity members provided at the elastic sheet member and formed of a conductive material and formed in a wire-like pattern, starting end portions of the continuity members being connected to either the movable contacts or the fixed contacts, and final end portions of the continuity members being exposed to an exterior of the elastic sheet member to enable a connection to a printed circuit board which is provided separately and independently at a reverse surface side of the elastic sheet member,

wherein, due to the movable contacts becoming electrically continuous with the fixed contacts, electric flow continuity paths of the continuity members to the printed circuit board are closed.

2. The elastic sheet structure having an electrical continuity function of claim 1, wherein the starting end portions of the continuity members are disposed so as to be dispersed at optional plural places in accordance with places at which the push portions are set, and the final end portions of the continuity members are disposed intensively at a small number of specific places.

3. The elastic sheet structure having an electrical continuity function of claim 1, wherein the small number of specific places at which the final end portions of the continuity members are disposed intensively are connecting portions which connect the continuity members to the printed circuit board.

4. The elastic sheet structure having an electrical continuity function of claim 1, wherein the starting end portions of the continuity members are structured to function as the movable contacts.

5. The elastic sheet structure having an electrical, continuity function of claim 1, wherein the continuity members are adhered to the elastic sheet member.

6. A printed circuit board structure comprising:

an elastic sheet member formed of a non-conductive material and formed in a sheet-shaped form, and having push portions which, when pushed, elastically deform and displace movable contacts, which are provided at reverse surface sides of the push portions, in a direction of pushing by a predetermined distance so as to make the movable contacts electrically continuous with fixed contacts

a printed circuit board fixed to a reverse surface side of the elastic sheet member, wherein the widthwise direction dimension of the printed circuit board is half or less of the widthwise direction dimension of the elastic sheet member; and

continuity members provided at the elastic sheet member and formed of a conductive material and formed in a wire-like pattern, starting end portions of the continuity members being connected to the movable contacts or the fixed contacts, and final end portions of the continuity members being connected to the printed circuit board,

wherein, due to the movable contacts becoming electrically continuous with the fixed contacts, electric flow continuity paths of the continuity members to the printed circuit board are closed.

7. The printed circuit board structure of claim 6, wherein the starting end portions of the continuity members are disposed so as to be dispersed at optional plural places in accordance with places at which the push portions are set, and the final end portions of the continuity members are disposed intensively at a small number of specific places.

8. The printed circuit board structure of claim 7, wherein the small number of specific places at which the final end portions of the continuity members are disposed intensively are connecting portions which connect the continuity members to the printed circuit board.

9. The printed circuit board structure of claim 6, wherein the starting end portions of the continuity members are structured to function as the movable contacts.

10. The printed circuit board structure of claim 6, wherein the continuity members are adhered to the elastic sheet member.

11. The printed circuit board structure of claim 6, wherein the final end portions of the continuity member are disposed intensively at a small number of specific places.

12. An elastic sheet structure having an electrical continuity function, comprising:

a sheet main body portion formed of a non-conductive material and in a sheet-shaped form, and having at least one push portion which elastically deforms by being pushed;

a fixed member provided at a reverse side of the sheet main body portion such that cavities having a predetermined width in a sheet thickness direction are formed between the sheet main body portion and the fixed member;

a fixed contact formed of a conductive material and provided so as to oppose each push portion at a position of the fixed member opposing the push portion; and

a continuity member formed of a conductive material and disposed in wire-shaped form at the sheet main body portion so as to form, for each push portion, an electric flow continuity path to a printed circuit board, the continuity member being disconnected at the position corresponding to the fixed contact at each push portion, and respective disconnected ends of the continuity member forming movable contacts,

wherein when the movable contacts are displaced in the sheet thickness direction by stress via each push portion and become electrically continuous with the corresponding fixed contact, the electric flow continuity path which was disconnected is closed via the fixed contact, and the electric flow continuity path to the printed circuit board is completed wherein a group of both ends of the respective continuity members is disposed intensively at a small number of specific places.

13. The elastic sheet structure having an electrical continuity function of claim 12, wherein both ends of the respective continuity members, which form final end portions of the respective electric flow continuity paths, are exposed to an exterior of the sheet main body portion as a connecting portion to the printed circuit board which is provided independently and separately at a reverse surface side of the elastic sheet structure.

14. The elastic sheet structure having an electrical continuity function of claim 13, wherein the continuity members are adhered to the sheet main body portion.

18. A printed circuit board structure comprising the elastic sheet structure of claim 12.

15. An elastic sheet structure having an electrical continuity function, comprising;

a sheet main body portion formed of a non-conductive material and in a sheet-shape form, and having at least one push portion which elastically deforms by being pushed;

a fixed member provided at a reverse side of the sheet main body portion such that cavities having a predetermined width in a sheet thickness direction are formed between the sheet main body portion and the fixed member;

a movable contact formed from a conductive material and provided at a position of a reverse surface of the sheet main body portion, which position opposes each push portion; and

a continuity member formed of a conductive material and disposed in wire-shaped form at the fixed member so as to form, for each push portion, an electric flow continuity path to a printed circuit board, and the continuity member being disconnected at the position corresponding to the movable contact, and respective disconnected ends of the continuity members forming fixed contacts,

wherein when the movable contact is displaced in the sheet thickness direction by stress via each push portion and becomes electrically continuous with the corresponding fixed contacts, the electric flow continuity path which was disconnected is closed via the movable contact, and the electric flow continuity path to the printed circuit board is completed, wherein both ends of the respective continuity members, which form final end portions of the electric flow continuity path, are exposed to an exterior of the fixed member as a connecting portion to the printed circuit board which is provided independently and separately at a reverse surface side of the elastic sheet structure.

16. The elastic sheet structure having an electrical continuity function of claim 15, wherein a group of both ends of the respective continuity members is disposed intensively at a small number of specific places.

17. The elastic sheet structure having an electrical continuity function of claim 15, wherein the continuity member is adhered to the fixed member.

19. A printed circuit board structure comprising the elastic sheet structure of claim 15.