EP0087918A1 - Interrupteur de clavier - Google Patents

Interrupteur de clavier Download PDF

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Publication number
EP0087918A1
EP0087918A1 EP83300940A EP83300940A EP0087918A1 EP 0087918 A1 EP0087918 A1 EP 0087918A1 EP 83300940 A EP83300940 A EP 83300940A EP 83300940 A EP83300940 A EP 83300940A EP 0087918 A1 EP0087918 A1 EP 0087918A1
Authority
EP
European Patent Office
Prior art keywords
key
actuating member
keyboard switch
aperture
membrane
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.)
Ceased
Application number
EP83300940A
Other languages
German (de)
English (en)
Inventor
David Conner Southward
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.)
Sinclair Research Ltd
Original Assignee
Sinclair Research 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
Application filed by Sinclair Research Ltd filed Critical Sinclair Research Ltd
Publication of EP0087918A1 publication Critical patent/EP0087918A1/fr
Ceased legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70—Switches 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
    • H01H13/702—Switches 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
    • H01H13/705—Switches 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 characterised by construction, mounting or arrangement of operating parts, e.g. push-buttons or keys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2215/00—Tactile feedback
    • H01H2215/004—Collapsible dome or bubble
    • H01H2215/022—Asymmetric; Elliptic; Square
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2221/00—Actuators
    • H01H2221/008—Actuators other then push button
    • H01H2221/016—Lever; Rocker

Definitions

  • the present invention relates to an improved keyboard switch.
  • One known type of electrical switch used in keyboards of, for example, data processing apparatus is a snap-effect switch which is moulded from silicone rubber into a sheet commonly providing a number of such switches.
  • Each switch is in the form of a truncated cone which, when depressed by direct finger action or via a key button, collapses suddenly to provide the snap effect.
  • the disadvantage of this type of switch is that the key has no lateral stability once it has been depressed and therefore reliability of operation is not assured.
  • the present invention provides a keyboard switch comprising a key actuating member having a key button and supporting portions on different sides of the key button, and electrical contact means arranged to change their state of conduction in response to pressure on and consequent relative movement of the key button, one of the supporting portions being relatively rigid thereby providing a cantilever effect to movement of the key button and another of the supporting portions being relatively resilient thereby providing a restoring force to the key button.
  • the present invention also provides a keyboard switch comprising a key actuating member and electrical contact means arranged to change their state of conduction in response to pressure on and consequent relative movement of the key actuating member, the electrical contact means including two contact portions separated by a membrane, the membrane having an aperture such that in an unstressed state the contact portions are held apart at the aperture, but when urged by the key actuating member the contact portions are brought together within the aperture, the membrane being located on a surface having a recess aligned with the key actuating member and a projection within the recess aligned with the membrane aperture, so that the contact, portions are brought together between the key actuating member and the projection.
  • the known switch 10 includes a portion moulded from silicone rubber in the form ef a sheet 1 1 having raised sides 12 in the shape of a truncated cone leading up to a key button 13 which carries a conductive member 14 on its lower surface, which member may be made of conductive rubber.
  • the sheet 11 is disposed over a circuit board 15 which carries contacts 16, commonly in an interdigitated array, the arrangement being that pressure on the button 13 collapses the cone and the conductive member 14 bridges the contacts 16, rendering the switch closed.
  • this type of switch has the above-mentioned disadvantage, namely that, once depressed, the switch has no lateral stability and reliable operation cannot be assured; if guides are fitted to restrain lateral movement of the key, the "touch" of the switch tends to be adversely affected.
  • the present invention seeks to overcome this disadvantage by providing a key switch with a cantilever action along one edge.
  • the preferred switch 20 has features in common with that shown in Figure 1 in that a sheet .21 includes raised sides 22, 22' leading up to a key button 23; a conductive member 24 is disposed over interdigitated contacts 26 provided over a circuit board 25.
  • the raised side 22' has a greater length and thickness than side 22 and includes a ridge 27 at the base where it continues along the board 25; the effect of this is that the side 22' provides a cantilever action such that when the key is depressed, the cantilevered side 22' provides a positive locating movement with lateral stability, while the side 22 provides the vertical restoring force and hence the "snap" feel to the switch.
  • Side edges 28, 29 to the switch, shown in Figure 3 can be arranged to contribute to the snap action, or may just act as a dust cover.
  • the conductive member 24 may be positioned on the key button in a similar manner to that shown in Figure 1; alternatively, since the key switch is cantilevered along the ridge 27 , the member 24 may be on the cantilevered side 22' as shown in Figure 2, the contacts 26 being positioned correspondingly.
  • This arrangement has two advantages; firstly, the switch action can occur before the key reaches its full depression so that if the finger is lifted slightly the contact is not immediately broken; secondly, the key button 23 itself may be hollowed out with consequent saving of expensive material.
  • FIG. 4 illustrates a modified key switch 40 in which, rather than use a piece of conductive silicone rubber to selectively bridge fixed contacts, a buckling member such as the illustrated tube section 41 can be used in a membrane- type switch.
  • a buckling member such as the illustrated tube section 41 can be used in a membrane- type switch.
  • electrical contacts 42 are screened on to layers of plastic film 43 and are separated from making contact by a very small distance; this can be achieved by fixing the layers 43 on opposite sides of a circuit board 44 provided with an aperture where the contacts are positioned.
  • the buckling member 41 forces the electrical contacts 42 to close.
  • the key switches 20, 40 previously described with reference to Figures 2 and 4 respectively, include a cantilever side having a greater length than the opposite side. Whilst this is of advantage in providing a cantilever action, it is possible to produce a key switch in which the cantilever side is no greater in length compared to the opposite side; all that is required is that it should have greater rigidity than the opposite side e.g. by being of greater thickness as shown in the drawings. Such an arrangement will provide a cantilever effect from the stiffer side 22', whereas the opposite side 22 will act to provide a restoring force upon depression of the key switch, and hence the required snap action.
  • Figure 3 shows a key switch including side edges 28, 29 and this is of advantage in providing a fully-enclosed switch which is protected from adverse environmental conditions.
  • the side edges can be dispensed with and the operating part of the key switch consist solely of a relatively rigid cantilever side and a relatively more flexible side providing the restoring force.
  • a key button which is rectangular in shape and has approximately rectangular cantilever and restoring sides; however, a circular key button could be provided with a cantilever side which would preferably operate on no more than one half of the circumference of the key button, the remaining surrounding side providing the restoring effect.
  • switch contacts are placed centrally under the key then it is possible that they may not be closed if the key is tipped because pressure on the key from the operator's finger may be released as soon as it is felt that one of the sides has reached the limit of its travel. It would of course be possible to have switch contacts under each side of the key but not only is this not very practicable but it is expensive in material (e.g. silver for the contacts). It is the aim of the modified embodiment to be described that no matter what angle the key is tipped through the central small switch contacts are still closed.
  • Figure 5 shows a section through an improved switch 50.
  • the key 51 is moulded in silicone rubber.
  • switch contacts 58 on flexible membranes 56 are pressed together sandwiched between a lower projection 55 on the key 51 and a pip 53 on the case mouking 52.
  • a shallow recess 54 Surrounding this pip 53 is a shallow recess 54 with a depth of the order of 0.02 inch (0.5mm) and a size larger than the key projection. If now one edge of the key is pressed, then one of the sides of the key bottom projection 55 may contact the bottom of the recess 54. However, although the key bottom projection 55 above the centre pip 53 may not be in contact with the membrane 56, the contacts 58 will still be closed by virtue of the deformation of the membrane 56 into the recess 54.
  • Figure 6 shows a plan view of the key switch 50 but the membrane 56 has been left out for the sake of clarity.
  • Figure 7 shows a plan view of the membrane 56. It consists of a sandwich of three plastics sheets, typically polycarbonate or polyester.
  • the central sheet is typically 0.01 inch (0.25mm) thick, has an adhesive coating on both surfaces and is punched with a relatively large diameter hole 57.
  • the upper and lower sheets are printed on their inside faces using a silver loaded ink so that the contacts 58 formed thereby are held a very small distance apart and deflection of either top or bottom surface of the membrane will result in their closing.
  • the bottom portion 55 of the key button 51 is shown as being uniformly flatyit can have many other forms in the interests of saving material.
  • the key could be hollow, circular or rectangular. Alternatively, it may be cross or diagonally ribbed.

Landscapes

  • Push-Button Switches (AREA)
EP83300940A 1982-02-25 1983-02-23 Interrupteur de clavier Ceased EP0087918A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB8205630 1982-02-25
GB8205630 1982-02-25
GB8211510 1982-04-21
GB8211510 1982-04-21

Publications (1)

Publication Number Publication Date
EP0087918A1 true EP0087918A1 (fr) 1983-09-07

Family

ID=26282082

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83300940A Ceased EP0087918A1 (fr) 1982-02-25 1983-02-23 Interrupteur de clavier

Country Status (1)

Country Link
EP (1) EP0087918A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2522192A1 (fr) * 1982-02-25 1983-08-26 Flex Key Corp Clavier a touches a membrane
FR2554630A1 (fr) * 1983-11-04 1985-05-10 Thomson Brandt Contacteur du type bouton-poussoir et son utilisation sur des claviers
EP2732753A4 (fr) * 2012-04-11 2015-09-30 Olympus Medical Systems Corp Couvercle d'interrupteur, dispositif d'interrupteur et endoscope

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3932722A (en) * 1974-04-16 1976-01-13 Nippo Communication Industrial Co., Ltd. Push button body for a push-button switch providing snap-action of the switch
US4129758A (en) * 1977-06-10 1978-12-12 Telaris Telecommunications, Inc. Keyboard switch assembly having flexible contact carrying member between contact carrying substrate and flexible, resilient, key-depressible bubble protrusions
FR2442502A1 (fr) * 1978-11-24 1980-06-20 Orega Cifte Clavier a touches a effet tactile de declenchement brusque
GB2039417A (en) * 1978-12-01 1980-08-06 Maag Gummi Contact pad switch
FR2457006A1 (fr) * 1977-01-31 1980-12-12 Rogers Corp Assemblage pour groupe de commutation tel que clavier a touches
GB2077464A (en) * 1980-04-08 1981-12-16 Citizen Watch Co Ltd Timepiece push-button structure
DE3044414A1 (de) * 1980-11-26 1982-06-24 Licentia Gmbh Elektrische schalteranordnung

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3932722A (en) * 1974-04-16 1976-01-13 Nippo Communication Industrial Co., Ltd. Push button body for a push-button switch providing snap-action of the switch
FR2457006A1 (fr) * 1977-01-31 1980-12-12 Rogers Corp Assemblage pour groupe de commutation tel que clavier a touches
US4129758A (en) * 1977-06-10 1978-12-12 Telaris Telecommunications, Inc. Keyboard switch assembly having flexible contact carrying member between contact carrying substrate and flexible, resilient, key-depressible bubble protrusions
FR2442502A1 (fr) * 1978-11-24 1980-06-20 Orega Cifte Clavier a touches a effet tactile de declenchement brusque
GB2039417A (en) * 1978-12-01 1980-08-06 Maag Gummi Contact pad switch
GB2077464A (en) * 1980-04-08 1981-12-16 Citizen Watch Co Ltd Timepiece push-button structure
DE3044414A1 (de) * 1980-11-26 1982-06-24 Licentia Gmbh Elektrische schalteranordnung

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IBM TECHNICAL DISCLOSURE BULLETIN, vol. 23, no. 9, February 1981, pages 4172-4178, New York, USA *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2522192A1 (fr) * 1982-02-25 1983-08-26 Flex Key Corp Clavier a touches a membrane
FR2554630A1 (fr) * 1983-11-04 1985-05-10 Thomson Brandt Contacteur du type bouton-poussoir et son utilisation sur des claviers
EP2732753A4 (fr) * 2012-04-11 2015-09-30 Olympus Medical Systems Corp Couvercle d'interrupteur, dispositif d'interrupteur et endoscope

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Legal Events

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

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB IT NL

17P Request for examination filed

Effective date: 19831110

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 19860201

RIN1 Information on inventor provided before grant (corrected)

Inventor name: SOUTHWARD, DAVID CONNER