EP0233296A1 - Contact rubber - Google Patents

Contact rubber Download PDF

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Publication number
EP0233296A1
EP0233296A1 EP86904938A EP86904938A EP0233296A1 EP 0233296 A1 EP0233296 A1 EP 0233296A1 EP 86904938 A EP86904938 A EP 86904938A EP 86904938 A EP86904938 A EP 86904938A EP 0233296 A1 EP0233296 A1 EP 0233296A1
Authority
EP
European Patent Office
Prior art keywords
rubber
oil
key top
contactor
layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86904938A
Other languages
German (de)
French (fr)
Other versions
EP0233296A4 (en
Inventor
Yasuhisa Osawa
Yasuko Kimura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Polymatech Co Ltd
Original Assignee
Polymatech Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP1985125217U external-priority patent/JPH0138822Y2/ja
Priority claimed from JP61093444A external-priority patent/JPS62252016A/en
Application filed by Polymatech Co Ltd filed Critical Polymatech Co Ltd
Publication of EP0233296A1 publication Critical patent/EP0233296A1/en
Publication of EP0233296A4 publication Critical patent/EP0233296A4/en
Withdrawn legal-status Critical Current

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Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H1/00Contacts
    • H01H1/06Contacts characterised by the shape or structure of the contact-making surface, e.g. grooved
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/78Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by the contacts or the contact sites
    • H01H13/785Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard characterised by the contacts or the contact sites characterised by the material of the contacts, e.g. conductive polymers
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/702Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2201/00Contacts
    • H01H2201/022Material
    • H01H2201/032Conductive polymer; Rubber
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2205/00Movable contacts
    • H01H2205/002Movable contacts fixed to operating part

Definitions

  • the present invention relates to a structure of contactor rubber in a switching means of, such as, key board for various electronics devices, such as, electronic portable computers, digital watches, word processors, personal computer, video disc arrangements, audio instruments, push-phone and so on, said contactor rubber serving as an interconnector between the electrodes of, such as, printed circuit board, LSI-chips etc.
  • contactor rubbers in which the conduction part thereof consists of an electroconductive rubber prepared by dispersing carbon powder in a mass of electrically insulating rubber, bonded under vulcanisation with an electroinsulating rubber; in which the surface of an eiectroinsulating rubber is printed with an electrically conductive ink; and so on.
  • a contactor rubber is employed in manipulator key for key operation of, such as, switching key board etc., and is arranged bodily with the key top for finger touch to effect key input.
  • fats or organic acid esters on the human finger will be transferred to the key top, which will penetrate through the material of key top and, after a prolonged period of time has been elapsed, reach to the contactor rubber and deposit thereon to cover it, increasing thereby the contact resistance upon contact of the contactor rubber with the pairing contact member.
  • oils and lower molecular weight siloxanes contained in the resin material of key top may separate and deposit on the conduction part, to thereby facitit.atc further the increase in the contact resistance and may-even hindcr the electric conduction in an extreme case.
  • insulating substances such as, oils, lower siloxanes and fats and esters from human finger onto the conduction part of the contactor rubber, by inserting between the conduction part and the resin body of the key top an oil-resistant layer.
  • the invention proposes to arrange an oil-resistant layer inserted between the conduction part and the resin body of the key top.
  • an oil-resistant insertion layer By incorporation of such an oil-resistant insertion layer, any deposition or penetration of electroinsulating substances from the environment or from the human finger can be prevented, even though the key board is placed in a factory or in a cooking room etc. where the atmosphere is contaminated with oily mists.
  • measures may be taken into consideration, in which a film of resin is interposed between the insulating resin body of the key top and the electroconductive rubber layer, in which said resin film is arranged between two electroconductive rubber layers, in which a layer of oil-resistant rubber is disposed over the electroinsulating key top body, and so on.
  • the oil-resistant layer is placed between two electroconductive rubber layers, it is possible that only these electroconductive layers are molded separately and are bonded afterwards onto the contactor rubber body with an adhesive to form an integral body. This is advantageous, since the adhesion work of the electroconductive layers onto the contactor rubber body can be effected without paying attention whether the face of the electroconductive layer is upside-down, permitting thus an easier work.
  • Fig. 1 shows one example of an arrangement according to the present Invention in a vertical section.
  • Fig. 2 is another example of the present invention shown also in a vertical section.
  • a key top of a key board has on its bottom face a layer of clcctroconduction part 2 under an interposition of an oil-resistant layer 3.
  • 4 is an electrode on a printed circuit board substrate 5.
  • the key top 1 is prepared by molding an insulating rubber.
  • an oil-resistant layer 3 is disposed by printing thereon with an oil-resistant substance derived from a non-vulcanized silicone rubber, such as those in which halogen or an organic compound is grafted on the principal siloxane polymer chain, or so on (such as fluorosilicone rubber, NBR, fluoride rubber, acrylic rubber, epichlorohydrin rubber etc.), and the surface of this oil-resistant layer 3 is further provided with an electroconductive layer 2 formed by printing an electroconductive ink thereon.
  • a non-vulcanized silicone rubber such as those in which halogen or an organic compound is grafted on the principal siloxane polymer chain, or so on (such as fluorosilicone rubber, NBR, fluoride rubber, acrylic rubber, epichlorohydrin rubber etc.)
  • an electroconductive layer 2 formed by printing an electroconductive ink thereon.
  • Fig. 2 which illustrates another embodiment of the present invention
  • the bottom face of the key top body 11 is provided with an electroconductive layer 14, an oil-resistant layer 13 and a further electroconductive layer 12.
  • the inner most electroconductive rubber layer 14, the resin film 13 and the outermost electroconductive rubber layer 12 are prepared separately each in a form of film, from which the respective sheet pieces are cut out by punching them in a predetermined shape, which are then bonded on the bottom face of the key top body 1 by an adhasive in the sequence mentioned above.

Abstract

A structure of a contact rubber used for various kinds of electronic appliances, and to preventing an oily substance which has penetrated into the contact rubber from the outside, or which is contained in the same rubber from coming out to the surface of a conductive portion of said rubber to thereby inhibit an increase in the contact resistance value of the conductive portion. The conductive portion (2) is formed on a key top (1), which is molded from an insulating rubber into the shape of a dome, via jn oil-proof portion (3) formed of a layer of an oil-proof rubber or a resin film.

Description

    Background of the Invention 1. Field of the Invention
  • The present invention relates to a structure of contactor rubber in a switching means of, such as, key board for various electronics devices, such as, electronic portable computers, digital watches, word processors, personal computer, video disc arrangements, audio instruments, push-phone and so on, said contactor rubber serving as an interconnector between the electrodes of, such as, printed circuit board, LSI-chips etc.
  • 2. Description of the Prior Art
  • There have been known contactor rubbers, in which the conduction part thereof consists of an electroconductive rubber prepared by dispersing carbon powder in a mass of electrically insulating rubber, bonded under vulcanisation with an electroinsulating rubber; in which the surface of an eiectroinsulating rubber is printed with an electrically conductive ink; and so on.
  • Brief Summary of the Invention
  • A contactor rubber is employed in manipulator key for key operation of, such as, switching key board etc., and is arranged bodily with the key top for finger touch to effect key input. Upon such a finger touch onto the key top, fats or organic acid esters on the human finger will be transferred to the key top, which will penetrate through the material of key top and, after a prolonged period of time has been elapsed, reach to the contactor rubber and deposit thereon to cover it, increasing thereby the contact resistance upon contact of the contactor rubber with the pairing contact member. Also, oils and lower molecular weight siloxanes contained in the resin material of key top may separate and deposit on the conduction part, to thereby facitit.atc further the increase in the contact resistance and may-even hindcr the electric conduction in an extreme case.
  • By the present invention, it is contemplated to prevent deposition of insulating substances, such as, oils, lower siloxanes and fats and esters from human finger onto the conduction part of the contactor rubber, by inserting between the conduction part and the resin body of the key top an oil-resistant layer.
  • Thus, the invention proposes to arrange an oil-resistant layer inserted between the conduction part and the resin body of the key top. By incorporation of such an oil-resistant insertion layer, any deposition or penetration of electroinsulating substances from the environment or from the human finger can be prevented, even though the key board is placed in a factory or in a cooking room etc. where the atmosphere is contaminated with oily mists.
  • For incorporating an oil-resistant layer, measures may be taken into consideration, in which a film of resin is interposed between the insulating resin body of the key top and the electroconductive rubber layer, in which said resin film is arranged between two electroconductive rubber layers, in which a layer of oil-resistant rubber is disposed over the electroinsulating key top body, and so on.
  • If the oil-resistant layer is placed between two electroconductive rubber layers, it is possible that only these electroconductive layers are molded separately and are bonded afterwards onto the contactor rubber body with an adhesive to form an integral body. This is advantageous, since the adhesion work of the electroconductive layers onto the contactor rubber body can be effected without paying attention whether the face of the electroconductive layer is upside-down, permitting thus an easier work.
  • Brief Description of the Drawings
  • Fig. 1 shows one example of an arrangement according to the present Invention in a vertical section.
  • Fig. 2 is another example of the present invention shown also in a vertical section.
  • Detailed Description of Preferred Embodiments
  • In Fig. 1, a key top of a key board has on its bottom face a layer of clcctroconduction part 2 under an interposition of an oil-resistant layer 3. 4 is an electrode on a printed circuit board substrate 5. The key top 1 is prepared by molding an insulating rubber. On the underside of the key top I projecting downwards, an oil-resistant layer 3 is disposed by printing thereon with an oil-resistant substance derived from a non-vulcanized silicone rubber, such as those in which halogen or an organic compound is grafted on the principal siloxane polymer chain, or so on (such as fluorosilicone rubber, NBR, fluoride rubber, acrylic rubber, epichlorohydrin rubber etc.), and the surface of this oil-resistant layer 3 is further provided with an electroconductive layer 2 formed by printing an electroconductive ink thereon. Of course, it is possible to incorporate oil-resistant layer by inserting it therebetween.
  • In Fig. 2, which illustrates another embodiment of the present invention, the bottom face of the key top body 11 is provided with an electroconductive layer 14, an oil-resistant layer 13 and a further electroconductive layer 12. The inner most electroconductive rubber layer 14, the resin film 13 and the outermost electroconductive rubber layer 12 are prepared separately each in a form of film, from which the respective sheet pieces are cut out by punching them in a predetermined shape, which are then bonded on the bottom face of the key top body 1 by an adhasive in the sequence mentioned above.

Claims (3)

1. A contactor rubber in which the electroconductive part thereof is arranged under an interposition of an oil-resistant layer on the bottom face of a key top molded from an electroinsulating rubber.
2. A contactor rubber according to Claim 1, wherein the oil-resistant layer consists of an oil-resistant rubber.
3. A contactor rubber according to Claim 1, wherein the oil-resistant layer consists of a synthetic resin fils.
EP19860904938 1985-08-16 1986-08-14 Contact rubber. Withdrawn EP0233296A4 (en)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP1985125217U JPH0138822Y2 (en) 1985-08-16 1985-08-16
JP125217/85 1985-08-16
JP93444/86 1986-04-24
JP61093444A JPS62252016A (en) 1986-04-24 1986-04-24 Formation of continuity part of rubber contact

Publications (2)

Publication Number Publication Date
EP0233296A1 true EP0233296A1 (en) 1987-08-26
EP0233296A4 EP0233296A4 (en) 1989-06-21

Family

ID=26434808

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19860904938 Withdrawn EP0233296A4 (en) 1985-08-16 1986-08-14 Contact rubber.

Country Status (5)

Country Link
EP (1) EP0233296A4 (en)
KR (1) KR900003800B1 (en)
DK (1) DK192087A (en)
ES (1) ES2001524A6 (en)
WO (1) WO1987001235A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0322514A2 (en) * 1987-12-30 1989-07-05 Hewlett-Packard Company Keyboard switch system
EP0366075A2 (en) * 1988-10-25 1990-05-02 Kabushiki Kaisha Toshiba Image processing method and system for radiological diagnostics
US7798413B2 (en) 2001-12-24 2010-09-21 L-1 Secure Credentialing, Inc. Covert variable information on ID documents and methods of making same
US7804982B2 (en) 2002-11-26 2010-09-28 L-1 Secure Credentialing, Inc. Systems and methods for managing and detecting fraud in image databases used with identification documents
US8083152B2 (en) 2001-12-24 2011-12-27 L-1 Secure Credentialing, Inc. Laser etched security features for identification documents and methods of making same

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2605163A1 (en) * 1986-10-01 1988-04-15 Mcb KEYBOARD WITH READING DEVICE
CA2118544A1 (en) * 1993-12-30 1995-07-01 Henry W. Krautter Reliability elastomeric keypads and method for making same
JP4442963B2 (en) * 1999-10-26 2010-03-31 パナソニック株式会社 Button switch
US7815124B2 (en) 2002-04-09 2010-10-19 L-1 Secure Credentialing, Inc. Image processing techniques for printing identification cards and documents
US7824029B2 (en) 2002-05-10 2010-11-02 L-1 Secure Credentialing, Inc. Identification card printer-assembler for over the counter card issuing
ATE491190T1 (en) 2003-04-16 2010-12-15 L 1 Secure Credentialing Inc THREE-DIMENSIONAL DATA STORAGE

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2472214A (en) * 1947-10-22 1949-06-07 Hurvitz Hyman Pressure responsive electrical resistor
US4528428A (en) * 1983-04-20 1985-07-09 Brother Kogyo Kabushiki Kaisha Key-holding structure of keyboard with curved operating surface of keys

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5485375U (en) * 1977-11-30 1979-06-16
JPS6222020Y2 (en) * 1979-08-08 1987-06-04
JPS5929932B2 (en) * 1980-04-26 1984-07-24 アルプス電気株式会社 Method for manufacturing a movable contact member for a push button switch
JPS59196517A (en) * 1983-11-02 1984-11-07 ブラザー工業株式会社 Keyboard

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2472214A (en) * 1947-10-22 1949-06-07 Hurvitz Hyman Pressure responsive electrical resistor
US4528428A (en) * 1983-04-20 1985-07-09 Brother Kogyo Kabushiki Kaisha Key-holding structure of keyboard with curved operating surface of keys

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ELECTRONIC ENGINEERIRNG September 1984, LONDEN page 189 - 192; "SPECIFYING AND USING RUBBER" *
See also references of WO8701235A1 *

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0322514A2 (en) * 1987-12-30 1989-07-05 Hewlett-Packard Company Keyboard switch system
EP0322514A3 (en) * 1987-12-30 1990-09-12 Hewlett-Packard Company Keyboard switch system
EP0366075A2 (en) * 1988-10-25 1990-05-02 Kabushiki Kaisha Toshiba Image processing method and system for radiological diagnostics
EP0366075A3 (en) * 1988-10-25 1991-02-06 Kabushiki Kaisha Toshiba Image processing method and system for radiological diagnostics
US7798413B2 (en) 2001-12-24 2010-09-21 L-1 Secure Credentialing, Inc. Covert variable information on ID documents and methods of making same
US8083152B2 (en) 2001-12-24 2011-12-27 L-1 Secure Credentialing, Inc. Laser etched security features for identification documents and methods of making same
US7804982B2 (en) 2002-11-26 2010-09-28 L-1 Secure Credentialing, Inc. Systems and methods for managing and detecting fraud in image databases used with identification documents

Also Published As

Publication number Publication date
WO1987001235A1 (en) 1987-02-26
KR900003800B1 (en) 1990-05-31
ES2001524A6 (en) 1988-06-01
KR880700442A (en) 1988-03-15
EP0233296A4 (en) 1989-06-21
DK192087D0 (en) 1987-04-14
DK192087A (en) 1987-04-14

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Legal Events

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19870619

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RIN1 Information on inventor provided before grant (corrected)

Inventor name: OSAWA, YASUHISA

Inventor name: KIMURA, YASUKO

A4 Supplementary search report drawn up and despatched

Effective date: 19890621

17Q First examination report despatched

Effective date: 19901217

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Effective date: 19910628

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Inventor name: KIMURA, YASUKO

Inventor name: OSAWA, YASUHISA