EP0241906B1 - Layered keyboard - Google Patents

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Publication number
EP0241906B1
EP0241906B1 EP87105500A EP87105500A EP0241906B1 EP 0241906 B1 EP0241906 B1 EP 0241906B1 EP 87105500 A EP87105500 A EP 87105500A EP 87105500 A EP87105500 A EP 87105500A EP 0241906 B1 EP0241906 B1 EP 0241906B1
Authority
EP
European Patent Office
Prior art keywords
pins
contact surfaces
membrane
switching contact
keyboard according
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.)
Expired - Lifetime
Application number
EP87105500A
Other languages
German (de)
French (fr)
Other versions
EP0241906A2 (en
EP0241906A3 (en
Inventor
Horst Hoffman
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.)
Wilhelm Ruf KG
Original Assignee
Wilhelm Ruf KG
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Filing date
Publication date
Application filed by Wilhelm Ruf KG filed Critical Wilhelm Ruf KG
Publication of EP0241906A2 publication Critical patent/EP0241906A2/en
Publication of EP0241906A3 publication Critical patent/EP0241906A3/en
Application granted granted Critical
Publication of EP0241906B1 publication Critical patent/EP0241906B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • H01H13/78—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 characterised by the contacts or the contact sites
    • H01H13/80—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 characterised by the contacts or the contact sites characterised by the manner of cooperation of the contacts, e.g. with both contacts movable or with bounceless contacts
    • 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
    • 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
    • H01H13/703—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 spacers between contact carrying layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2201/00—Contacts
    • H01H2201/008—Both contacts movable
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2203/00—Form of contacts
    • H01H2203/032—Metal foil
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2209/00—Layers
    • H01H2209/01—Increasing rigidity; Anti-creep
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2209/00—Layers
    • H01H2209/014—Layers composed of different layers; Lubricant in between
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2211/00—Spacers
    • H01H2211/006—Individual areas
    • H01H2211/02—Pins forming part of substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2229/00—Manufacturing
    • H01H2229/036—Manufacturing ultrasonic
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2229/00—Manufacturing
    • H01H2229/042—Snap coupling; Snap mounting

Definitions

  • the invention relates to a membrane keyboard according to the preamble of claim 1.
  • a membrane keyboard is known from DE-A-31 08 183.
  • This membrane keyboard consists of a coding plate with electrical switch contact surfaces and a flexible membrane arranged at a distance from it, which has electrically conductive areas.
  • the distance between the coding plate and membrane is produced by bar-shaped spacers which are arranged laterally next to the switching contact surfaces of the coding plate and which are anchored in holes of the coding plate with short pins protruding from the spacers. In the top view, the bar-shaped spacers extend over the full length of the switch contact surfaces and even protrude slightly to the side.
  • An electrical contact is made in that the flexible membrane is pressed down, for example by finger pressure, so that an electrically conductive area protrudes through the cutouts in the spacer layer and electrically connects the associated switch contact surfaces on the coding plate.
  • the object of the invention is therefore to improve the membrane keyboard of the type mentioned in such a way that it is very reliable with a simplified structure.
  • the functional reliability relates to the fact that incorrect contacts are prevented and that the individual components of the membrane keyboard can no longer slide against one another. Furthermore, the membrane keyboard should be easy to manufacture and assemble.
  • the support plate 10 which for example also contains the housing of an electrotechnical function group, for example the housing of a remote control transmitter for television sets, the housing of a Calculator or the housing of a dialing keypad can be made of electrically non-conductive material, such as Plastic and has pins 11 projecting perpendicularly from their base. These pins are preferably connected in one piece to the support plate. However, they can also be made as separate parts and subsequently glued, inserted, screwed, riveted, etc.
  • the cross section of the pins 11 can be circular, square, rectangular, triangular or of any other shape.
  • the support plate 10 has side walls 15, the upper end face of which lies in one plane with the upper end face of the pins 11. Furthermore, these side walls 15 have a widening 17 at their upper end, which in turn has a bevel 16 which faces inwards, ie. H. points to the opposite side wall.
  • the membrane keyboard has a coding plate 20, the switching contact surfaces 21 and conductor tracks, not shown.
  • the switch contact surfaces are designed in a conventional manner, for example accordingly the switching contact surfaces of US-A-4 365 130 or US-A-4 391 845.
  • the coding plate 20 itself is made of electrically insulating material. It can also consist of a thin, flexible film.
  • the switch contact surfaces and the conductor tracks are produced in a conventional manner, for example by etching or printing, from an electrically conductive material.
  • the coding plate 20 has a plurality of openings 22 which are arranged such that one of the pins 11 projects through one of the openings.
  • the coding plate 20 is inserted into the support plate 10 so that its underside rests on the bottom of the support plate.
  • the pins 11 prevent it from slipping sideways. Furthermore, it is centered relative to the support plate.
  • the third assembly is the membrane 30, which consists of elastic material and is electrically conductive at least opposite to the switch contact surfaces 21 on its underside.
  • the membrane 30 is electrically conductive on its entire underside, for example by a coating of conductive lacquer.
  • the membrane 30 lies on the upper end face of the pins 11 and on the edges of the side walls 15.
  • the length of the pins 11 is selected so that the pins protrude from the coding plate 20 to such an extent that they hold the membrane at such a distance above the switching contact surfaces that, on the one hand, undesirable contact between the membrane and the switching contact surfaces 21 in the event of mechanical shocks are avoided, and on the other hand the membrane 30 touches the switching contact surfaces 21 of the selected switching contact by finger pressure at selected “switching points” in the direction of the arrows 32 and thus electrically connect them to one another.
  • the widening 17 of the side walls 15 acts together with the bevels 16 as a snap lock, which secures the coding plate 20 against falling out.
  • the coding plate 20 can be glued to the support plate 10 and in particular in the area of the pins 11.
  • an adhesive can be present between the inside diameter of the openings 22 and the outside diameter of the pins 11.
  • the pins 11 can be given a thickened head 12 by hot upsetting or ultrasonic welding, as a result of which the coding plate 20 is also positively secured in the area of the pins against falling out.
  • care must be taken that the length of the pins 11 is selected such that the shortening that occurs during hot upsetting still leaves a sufficient distance between the underside 31 of the membrane 30 and the switch contact surfaces 21.
  • a "four-point support” is provided, ie the membrane is supported with respect to each switching contact surface 21 by four pins. Since in FIGS. 3 and 4 the switching contact surfaces 21 are arranged in rows and columns in a uniform division are, in both embodiments, the pins 11 can be arranged rotationally symmetrically with respect to the center of the switch contact surface, ie they lie on a circle, the center of which is also the center of the switch contact surface.
  • the pins 11 lie at intersection points of diagonals 23, which connect the center points of diagonally adjacent switching contact surfaces 21 to one another. In relation to the row and column arrangement of the switching contact surfaces 21, the pins 11 arranged around a switching contact surface thus form a square.
  • FIG. 4 is also a "four-point support".
  • the individual pins 11 lie on straight lines 24, which connect the center points of the switching contact surfaces 21 in rows and columns. Furthermore, the pins 11 lie on these lines in such a way that they lie exactly in the middle between two adjacent switching contact surfaces.
  • the pins surrounding a switch contact surface thus also span a square, which, however, is rotated by 45 ° with respect to the squares of FIG. 3.
  • FIG. 6 shows a further development of the support plate 10.
  • This has webs 13 and 14 projecting perpendicularly from their base for the purpose of stiffening, a pin 11 each projecting upwards at the crossings of the webs 13 and 14.
  • the coding plate is then only on the upper end of the webs.
  • the side walls 15 are raised, similarly to FIG. 1, so that their end faces lie in one plane with the end faces of the pins 11.
  • the membrane then also lies here on the pins 11 and the end faces of the side walls 15.

Description

Die Erfindung bezieht sich auf eine Membrantastatur gemäß dem Oberbegriff des Patentanspruches 1. Eine solche Membrantastatur ist aus der DE-A-31 08 183 bekannt. Diese Membrantastatur besteht aus einer Codierplatte mit elektrischen Schaltkontaktflächen und einem im Abstand dazu angeordneten, flexiblen Membran, die elektrisch leitfähige Bereiche aufweist. Der Abstand zwischen Codierplatte und Membran wird durch balkenförmige Abstandhalter hergestellt, die seitlich neben den Schaltkontaktflächen der Codierplatte angeordnet sind und die mit einstückig von den Abstandhaltern abstehenden kurzen Stiften in Löchern der Codierplatte verankert sind. In der Draufsicht erstrecken sich die balkenförmigen Abstandhalter über die volle Länge der Schaltkontaktflächen und ragen sogar noch etwas seitlich darüberhinaus.The invention relates to a membrane keyboard according to the preamble of claim 1. Such a membrane keyboard is known from DE-A-31 08 183. This membrane keyboard consists of a coding plate with electrical switch contact surfaces and a flexible membrane arranged at a distance from it, which has electrically conductive areas. The distance between the coding plate and membrane is produced by bar-shaped spacers which are arranged laterally next to the switching contact surfaces of the coding plate and which are anchored in holes of the coding plate with short pins protruding from the spacers. In the top view, the bar-shaped spacers extend over the full length of the switch contact surfaces and even protrude slightly to the side.

Eine weitere Membrantastatur ist aus der US-A-4 365 130 bekannt.Another membrane keyboard is known from US-A-4,365,130.

Sie hat - von unten nach oben - folgenden Aufbau:

  • eine Stützplatte aus relativ hartem Material
  • darüber liegt eine dünne Schicht aus Klebstoff und
  • darüber eine Codierplatte aus flexiblem, elektrisch isolierendem Material.
Die Codierplatte besitzt an ihrer Oberseite elektrische Schaltkontaktflächen und Leiterbahnen, die in herkömmlicher Weise, beispielsweise mittels Siebdruck- oder Ätztechnik aus Kupfer, Silber oder sonstigem leitfähigen Material aufgebracht sind. Über der Codierplatte ist eine Abstandhalteschicht aus elektrisch isolierendem Material angeordnet, wobei diese Schicht gegenüberliegend zu den Schaltkontaktflächen Aussparungen besitzt. Darüber liegt eine flexible Membran, die gegenüberliegend zu den Aussparungen an ihrer Unterseite elektrisch leitfähige Bereiche aufweist. Darüber befindet sich schließlich ein Deckel, der wiederum gegenüberliegend zu den Schaltkontaktflächen Aussparungen besitzt.It has the following structure - from bottom to top:
  • a support plate made of relatively hard material
  • there is a thin layer of adhesive and
  • above it is a coding plate made of flexible, electrically insulating material.
The upper side of the coding plate has electrical switching contact surfaces and conductor tracks which are applied in a conventional manner, for example by means of screen printing or etching technology, made of copper, silver or other conductive material. A spacer layer made of electrically insulating material is arranged above the coding plate, this layer being opposite has recesses to the switch contact surfaces. Above this is a flexible membrane, which has electrically conductive areas opposite to the cutouts on its underside. Finally there is a cover, which in turn has cutouts opposite the switch contact surfaces.

Ein elektrischer Kontakt wird dadurch geschlossen, daß die flexible Membran beispielsweise per Fingerdruck niedergedrückt wird, so daß ein elektrisch leitfähiger Bereich durch die Aussparungen der Abstandhalteschicht hindurchragt und die zugehörigen Schaltkontaktflächen auf der Codierplatte elektrisch miteinander verbindet.An electrical contact is made in that the flexible membrane is pressed down, for example by finger pressure, so that an electrically conductive area protrudes through the cutouts in the spacer layer and electrically connects the associated switch contact surfaces on the coding plate.

Ähnliche Membrantastaturen sind auch aus folgenden Druckschriften bekannt:

  • DE-A-30 12 717
  • US-A-4 405 849
  • US-A-4 385 215.
Similar membrane keyboards are also known from the following publications:
  • DE-A-30 12 717
  • US-A-4,405,849
  • US-A-4,385,215.

Die Verwendung einer eigenen Abstandhaltefolie ist aufwendig. Zum einen muß ein zusätzliches Bauteil gefertigt werden und zum anderen muß dieses bei der Montage präzise ausgerichtet und fixiert werden, damit er sich beim späteren Betrieb nicht verschiebt.The use of a separate spacer film is complex. On the one hand, an additional component must be manufactured and, on the other hand, this must be precisely aligned and fixed during assembly so that it does not shift during later operation.

Es ist daher auch schon vorgeschlagen worden (vgl. EP-A1-0 124 862, DE-A-26 23 229, US-A-4 391 845), statt einer Abstandhaltefolie unmittelbar auf die Codierplatte Abstandhalter bzw. sog. Spacer aufzubringen und zwar in Form von aufgedruckten (z.B. Siebdruck) Isolierschichten oder in Form von aufgeklebten Distanzstücken.It has therefore already been proposed (cf. EP-A1-0 124 862, DE-A-26 23 229, US-A-4 391 845) to apply spacers or so-called spacers directly to the coding plate instead of a spacer film in the form of printed (eg screen printing) insulating layers or in the form of glued-on spacers.

Das Aufdrucken oder Aufkleben von Spacern hat allerdings folgende Nachteile:
Es wird ein zusätzlicher Arbeitsschritt erforderlich, der neben dem aufwendigen Ausrichten einer Siebdruckmaschine auch Trocknungs- oder Aushärtzeiten mit sich bringt. Weiterhin ist es beim Siebdruck nicht immer sicherzustellen, daß Schichten ausreichender Dicke aufgedruckt werden.However, printing or sticking on spacers has the following disadvantages:
An additional step is required, which in addition to the time-consuming alignment of a screen printing machine also entails drying or curing times. Furthermore, it is not always possible to ensure that layers of sufficient thickness are printed on during screen printing.

Aufgabe der Erfindung ist es daher, die Membrantastatur der eingangs genannten Art dahingehend zu verbessern, daß sie bei vereinfachtem Aufbau sehr funktionssicher ist.The object of the invention is therefore to improve the membrane keyboard of the type mentioned in such a way that it is very reliable with a simplified structure.

Die Funktionssicherheit bezieht sich darauf, daß Fehlkontakte verhindert werden und daß die einzelnen Bauteile der Membrantastatur nicht mehr gegeneinander verrutschen können. Weiterhin soll die Membrantastatur einfach herzustellen und zu montieren sein.The functional reliability relates to the fact that incorrect contacts are prevented and that the individual components of the membrane keyboard can no longer slide against one another. Furthermore, the membrane keyboard should be easy to manufacture and assemble.

Die oben angegebene Aufgabe wird durch die im Patentanspruch 1 angegebenen Merkmale gelöst. Vorteilhafte Ausgestaltungen und Weiterbildungen der Erfindung sind den Unteransprüchen zu entnehmen.The above object is achieved by the features specified in claim 1. Advantageous refinements and developments of the invention can be found in the subclaims.

Im folgenden wird die Erfindung anhand eines Ausführungsbeispieles im Zusammenhang mit der Zeichnung ausführlicher erläutert. Es zeigt:

Fig. 1
einen Querschnitt der Membrantastatur nach der Erfindung;
Fig. 2
einen Schnitt einer Einzelheit nach einer Weiterbildung der Erfindung;
Fig. 3, 4 und 5
Draufsichten der Membrantastatur bei fortgelassener Membran zur Darstellung der Anordnung der Stifte und
Fig. 6
eine perspektivische Ansicht einer Variante der bei der Erfindung verwendeten Stützplatte.
In the following, the invention is explained in more detail using an exemplary embodiment in connection with the drawing. It shows:
Fig. 1
a cross section of the membrane keyboard according to the invention;
Fig. 2
a section of a detail according to a development of the invention;
3, 4 and 5
Top views of the membrane keyboard with the omitted Membrane to show the arrangement of the pins and
Fig. 6
a perspective view of a variant of the support plate used in the invention.

Die Membrantastatur der Fig. 1 besteht nur noch aus drei Grundkomponenten, nämlich einer Stützplatte 10, einer Codierplatte 20 und einer Membran 30. Die Stützplatte 10, die beispielsweise auch das Gehäuse einer elektrotechnischen Funktionsgruppe, beispielsweise das Gehäuse eines Fernbediensenders für Fernsehgeräte, das Gehäuse eines Taschenrechners oder das Gehäuse einer Wähltastatur bei Telefonapparaten sein kann, ist aus elektrisch nicht leitendem Material, wie z.B. Kunststoff und weist senkrecht von ihrem Boden abstehende Stifte 11 auf. Vorzugsweise sind diese Stifte einstückig mit der Stützplatte verbunden. Sie können jedoch auch als separate Teile hergestellt sein und nachträglich aufgeklebt, eingesetzt, eingeschraubt, vernietet usw. sein. Der Querschnitt der Stifte 11 kann kreisförmig, quadratisch, rechteckig, dreieckig oder von sonstiger Form sein.1 consists of only three basic components, namely a support plate 10, a coding plate 20 and a membrane 30. The support plate 10, which for example also contains the housing of an electrotechnical function group, for example the housing of a remote control transmitter for television sets, the housing of a Calculator or the housing of a dialing keypad can be made of electrically non-conductive material, such as Plastic and has pins 11 projecting perpendicularly from their base. These pins are preferably connected in one piece to the support plate. However, they can also be made as separate parts and subsequently glued, inserted, screwed, riveted, etc. The cross section of the pins 11 can be circular, square, rectangular, triangular or of any other shape.

In dem Ausführungsbeispiel der Fig. 1 hat die Stützplatte 10 Seitenwände 15, deren obere Stirnfläche in einer Ebene mit der oberen Stirnfläche der Stifte 11 liegt. Weiterhin haben diese Seitenwände 15 an ihrem oberen Ende eine Verbreiterung 17, welche ihrerseits eine Abschrägung 16 besitzt, die nach innen, d. h. zur gegenüberliegenden Seitenwand weist.In the exemplary embodiment in FIG. 1, the support plate 10 has side walls 15, the upper end face of which lies in one plane with the upper end face of the pins 11. Furthermore, these side walls 15 have a widening 17 at their upper end, which in turn has a bevel 16 which faces inwards, ie. H. points to the opposite side wall.

Weiterhin besitzt die Membrantastatur eine Codierplatte 20, die Schaltkontaktflächen 21 sowie nicht dargestellte Leiterbahnen besitzt. Die Schaltkontaktflächen sind in herkömmlicher Weise gestaltet, beispielsweise entsprechend den Schaltkontaktflächen der US-A-4 365 130 oder der US-A-4 391 845. Die Codierplatte 20 selbst ist aus elektrisch isolierendem Material. Sie kann auch aus einer dünnen, flexiblen Folie bestehen. Die Schaltkontaktflächen und die Leiterbahnen sind in herkömmlicher Weise, beispielsweise durch Ätzen oder Aufdrucken aus elektrisch leitfähigem Material hergestellt. Die Codierplatte 20 besitzt mehrere Öffnungen 22, die so angeordnet sind, daß jeweils durch eine der Öffnungen einer der Stifte 11 hindurchragt. Die Codierplatte 20 wird dabei so in die Stützplatte 10 eingesetzt, daß ihre Unterseite auf dem Boden der Stützplatte aufliegt. Durch die Stifte 11 ist sie gegen seitliches Verrutschen gesichert. Weiterhin ist sie dadurch gegenüber der Stützplatte zentriert.Furthermore, the membrane keyboard has a coding plate 20, the switching contact surfaces 21 and conductor tracks, not shown. The switch contact surfaces are designed in a conventional manner, for example accordingly the switching contact surfaces of US-A-4 365 130 or US-A-4 391 845. The coding plate 20 itself is made of electrically insulating material. It can also consist of a thin, flexible film. The switch contact surfaces and the conductor tracks are produced in a conventional manner, for example by etching or printing, from an electrically conductive material. The coding plate 20 has a plurality of openings 22 which are arranged such that one of the pins 11 projects through one of the openings. The coding plate 20 is inserted into the support plate 10 so that its underside rests on the bottom of the support plate. The pins 11 prevent it from slipping sideways. Furthermore, it is centered relative to the support plate.

Die dritte Baugruppe ist die Membran 30, die aus elastischem Material besteht und zumindest gegenüberliegend zu den Schaltkontaktflächen 21 an ihrer Unterseite elektrisch leitfähig ist. Beim Ausführungsbeispiel der Neuerung ist die Membran 30 an ihrer gesamten Unterseite elektrisch leitfähig, beispielsweise durch eine Beschichtung aus leitfähigem Lack. Die Membran 30 liegt auf der oberen Stirnseite der Stifte 11 und an den Rändern der Seitenwände 15 auf. Die Länge der Stifte 11 ist so gewählt, daß die Stifte soweit aus der Codierplatte 20 herausragen, daß sie die Membran in einem solchen Abstand oberhalb der Schaltkontaktflächen halten, daß einerseits unerwünschte Berührungen zwischen der Membran und der Schaltkontaktflächen 21 bei mechanischen Erschütterungen vermieden werden und andererseits die Membran 30 durch Fingerdruck an ausgewählten "Schaltpunkten" in Richtung der Pfeile 32 die Schaltkontaktflächen 21 des ausgewählten Schaltkontaktes berühren und damit elektrisch miteinander verbinden.The third assembly is the membrane 30, which consists of elastic material and is electrically conductive at least opposite to the switch contact surfaces 21 on its underside. In the exemplary embodiment of the innovation, the membrane 30 is electrically conductive on its entire underside, for example by a coating of conductive lacquer. The membrane 30 lies on the upper end face of the pins 11 and on the edges of the side walls 15. The length of the pins 11 is selected so that the pins protrude from the coding plate 20 to such an extent that they hold the membrane at such a distance above the switching contact surfaces that, on the one hand, undesirable contact between the membrane and the switching contact surfaces 21 in the event of mechanical shocks are avoided, and on the other hand the membrane 30 touches the switching contact surfaces 21 of the selected switching contact by finger pressure at selected “switching points” in the direction of the arrows 32 and thus electrically connect them to one another.

Die Verbreiterung 17 der Seitenwände 15 wirkt zusammen mit den Abschrägungen 16 als Schnappverschluß, der die Codierplatte 20 gegen ein Herausfallen sichert.The widening 17 of the side walls 15 acts together with the bevels 16 as a snap lock, which secures the coding plate 20 against falling out.

Als weitere Sicherung kann die Codierplatte 20 an der Stützplatte 10 angeklebt sein und insbesondere im Bereich der Stifte 11. Mit anderen Worten kann zwischen dem Innendurchmesser der Öffnungen 22 und dem Außendurchmesser der Stifte 11 ein Klebstoff vorhanden sein.As a further safeguard, the coding plate 20 can be glued to the support plate 10 and in particular in the area of the pins 11. In other words, an adhesive can be present between the inside diameter of the openings 22 and the outside diameter of the pins 11.

Nach der in Fig. 2 gezeigten Weiterbildung der Erfindung können die Stifte 11 durch Warmverstauchung oder Ultraschallverschweißung einen verdickten Kopf 12 erhalten, wodurch die Codierplatte 20 auch im Bereich der Stifte formschlüssig gegen ein Herausfallen gesichert ist. Hier ist bei der Fertigung der Stützplatte darauf zu achten, daß die Länge der Stifte 11 so gewählt ist, daß durch die beim Warmverstauchen erfolgte Verkürzung noch ein ausreichender Abstand zwischen der Unterseite 31 der Membran 30 und den Schaltkontaktflächen 21 verbleibt.According to the development of the invention shown in FIG. 2, the pins 11 can be given a thickened head 12 by hot upsetting or ultrasonic welding, as a result of which the coding plate 20 is also positively secured in the area of the pins against falling out. Here, when manufacturing the support plate, care must be taken that the length of the pins 11 is selected such that the shortening that occurs during hot upsetting still leaves a sufficient distance between the underside 31 of the membrane 30 and the switch contact surfaces 21.

Die Fig. 3, 4 und 5 zeigen verschiedene Varianten für die Anordnung der Stifte 11 (und der Öffnungen 22) bezüglich der Schaltkontaktflächen 21. Die Schaltkontaktflächen sind in diesen Figuren lediglich als Kreise dargestellt. Es sei jedoch darauf hingewiesen, daß jegliche bekannte Formen von Schaltkontaktflächen hier verwendet werden können.3, 4 and 5 show different variants for the arrangement of the pins 11 (and the openings 22) with respect to the switch contact surfaces 21. The switch contact surfaces are only shown as circles in these figures. However, it should be noted that any known forms of switch pads can be used here.

In den Fig. 3 und 4 ist eine "Vierpunktabstützung" vorgesehen, d. h. die Membran wird bezüglich jeder Schaltkontaktfläche 21 durch vier Stifte abgestützt. Da in den Figuren 3 und 4 die Schaltkontaktflächen 21 zeilen-und spaltenweise in gleichförmiger Teilung angeordnet sind, können bei beiden Ausführungsbeispielen die Stifte 11 rotationssymmetrisch bezogen auf die Mitte des Schaltkontaktflächen angeordnet sein, d.h. sie liegen auf einem Kreis, dessen Mittelpunkt auch der Mittelpunkt der Schaltkontaktfläche ist.3 and 4, a "four-point support" is provided, ie the membrane is supported with respect to each switching contact surface 21 by four pins. Since in FIGS. 3 and 4 the switching contact surfaces 21 are arranged in rows and columns in a uniform division are, in both embodiments, the pins 11 can be arranged rotationally symmetrically with respect to the center of the switch contact surface, ie they lie on a circle, the center of which is also the center of the switch contact surface.

Beim Ausführungsbeispiel der Fig. 3 liegen die Stifte 11 an Schnittpunkten von Diagonalen 23, die die Mittelpunkte von diagonal benachbarten Schaltkontaktflächen 21 miteinander verbinden. Bezogen auf die zeilen- und spaltenweise Anordnung der Schaltkontaktflächen 21 bilden die um eine Schaltkontaktfläche angeordneten Stifte 11 also ein Quadrat.In the exemplary embodiment in FIG. 3, the pins 11 lie at intersection points of diagonals 23, which connect the center points of diagonally adjacent switching contact surfaces 21 to one another. In relation to the row and column arrangement of the switching contact surfaces 21, the pins 11 arranged around a switching contact surface thus form a square.

Beim Ausführungsbeispiel der Fig. 4 handelt es sich ebenfalls um eine "Vierpunktabstützung". Die einzelnen Stifte 11 liegen dabei jedoch auf Geraden 24, welche die Mittelpunkte der Schaltkontaktflächen 21 zeilen- und spaltenweise verbinden. Weiterhin liegen die Stifte 11 so auf diesen Linien, daß sie jeweils genau auf der Mitte zwischen zwei benachbarten Schaltkontaktflächen liegen. Die eine Schaltkontaktfläche umgebenden Stifte spannen damit ebenfalls ein Quadrat auf, das gegenüber den Quadraten der Fig. 3 jedoch um 45° gedreht ist.The embodiment of FIG. 4 is also a "four-point support". However, the individual pins 11 lie on straight lines 24, which connect the center points of the switching contact surfaces 21 in rows and columns. Furthermore, the pins 11 lie on these lines in such a way that they lie exactly in the middle between two adjacent switching contact surfaces. The pins surrounding a switch contact surface thus also span a square, which, however, is rotated by 45 ° with respect to the squares of FIG. 3.

In Fig. 5 ist eine "Dreipunktabstützung" gezeigt, d. h. pro Schaltkontaktfläche 21 ist die Membran nur durch drei Stifte 11 abgestützt. Diese spannen daher bezüglich der jeweiligen Schaltkontaktfläche 21 ein Dreieck auf. Sofern der Abstand der Schaltkontaktflächen 21 in Zeilen- und Spaltenrichtung gleich ist, werden damit gleichseitige Dreiecke gebildet, in deren Flächenschwerpunkt der Mittelpunkt der Schaltkontaktflächen liegt.5 shows a "three-point support", ie the membrane is supported by only three pins 11 per switching contact surface 21. These therefore span a triangle with respect to the respective switching contact surface 21. If the distance between the switch contact surfaces 21 in the row and column direction is the same, equilateral triangles are formed with the center of the area of the center point of the switch contact surfaces.

Ist dagegen - wie in Fig. 5 gezeigt - der Abstand in Zeilen- und Spaltenrichtung verschieden, so werden gleichschenklige Dreiecke gebildet, wie durch die Linien 25, 26 und 27 angedeutet. Weiterhin liegen die Stifte 11 auf Linien 26, die zeilenweise genau in der Mitte zwischen benachbarten Zeilen von Schaltkontaktflächen verläuft.If, on the other hand, as shown in FIG. 5, the distance in the row and column direction is different, isosceles triangles are formed, as indicated by lines 25, 26 and 27. Furthermore, the pins 11 lie on lines 26, which line by line runs exactly in the middle between adjacent lines of switching contact surfaces.

Fig. 6 zeigt noch eine Weiterbildung der Stützplatte 10. Diese hat zur Versteifung senkrecht von ihrem Boden abstehende Stege 13 und 14, wobei an Kreuzungspunkten der Stege 13 und 14 je ein Stift 11 nach oben absteht. Die Codierplatte liegt dann nur auf der oberen Stirnseite der Stege auf. Auch hier sind die Seitenwände 15 - ähnlich wie in Fig. 1 - hochgezogen, so daß ihre Stirnflächen in einer Ebene mit den Stirnflächen der Stifte 11 liegt. Die Membran liegt dann also auch hier auf den Stiften 11 und den Stirnflächen der Seitenwände 15 auf.6 shows a further development of the support plate 10. This has webs 13 and 14 projecting perpendicularly from their base for the purpose of stiffening, a pin 11 each projecting upwards at the crossings of the webs 13 and 14. The coding plate is then only on the upper end of the webs. Here, too, the side walls 15 are raised, similarly to FIG. 1, so that their end faces lie in one plane with the end faces of the pins 11. The membrane then also lies here on the pins 11 and the end faces of the side walls 15.

Claims (12)

  1. A membrane keyboard with an encoding plate (20), which comprises electrical switching contact surfaces (21), with a flexible membrane (30), which is arranged at a distance from the encoding plate (20) and comprises electrically conductive areas at least opposite the switching contact surfaces, electrically non-conductive spacing elements being provided between the encoding plate (20) and the membrane (30) and extending from openings (22) in the encoding plate (20) provided adjacent the switching contact surfaces (21) above the surface of the encoding plate to the membrane (30), characterised in that a support plate (10) is provided, on which the encoding plate (20) is arranged, the spacing elements are formed by pins (11), the pins (11) are anchored on the support plate (10) and extending from said support plate (10) project through the openings (22) in the encoding plate (20), and the cross section of the pins (11) corresponds to the cross section of the openings (22).
  2. A membrane keyboard according to claim 1, characterised in that the pins (11) are integrally connected with the support plate (10).
  3. A membrane keyboard according to claim 1 or 2, characterised in that an adhesive is provided between the internal diameter of the openings (22) in the encoding plate (20) and the external diameter of the pins (11).
  4. A membrane keyboard according to one of claims 1 to 3, characterised in that, viewed from above, the openings (22) and the pins (11) are arranged rotationally symmetrical to the centre points of the switching contact surfaces (21).
  5. A membrane keyboard according to claim 4, characterised in that the openings (22) and the pins (11) are arranged in a uniform grid in such a manner that they lie on the points of intersection of diagonals (23) connecting the centre points of adjacent switching contact surfaces (21).
  6. A membrane keyboard according to claim 4, characterised in that the openings (22) and the pins (11) are arranged in a uniform grid in such a manner that they lie on straight lines (24) connecting the centre points of the switching contact surfaces (21) in rows and columns, the openings (22) and the pins (11) also being arranged at equal distances from the centre points of directly adjacent switching contact surfaces.
  7. A membrane keyboard according to one of claims 1 to 3, characterised in that the openings (22) and the pins (11) are arranged in a circle around the respective switching contact surfaces (21) in such a manner that connecting lines (25, 26, 27) form a triangle, in which the centre point of the associated switching contact surfaces (21) lies.
  8. A membrane keyboard according to one of claims 1 to 7, characterised in that the support plate (10) comprises webs (13, 14) extending vertically from its base, a pin (11) projecting above the upper edge of the webs at each point of intersection of said webs.
  9. A membrane keyboard according to claim 8, characterised in that the side walls (15) of the support plate (10) lie in a plane with the upper end face of the pins (11).
  10. A membrane keyboard according to claim 9, characterised in that the side walls (15) of the support plate (10) comprise an enlarged head (17) having a bevel (16) inclined inwards, i.e. towards the opposite side wall.
  11. A membrane keyboard according to one of claims 1 to 10, characterised in that the membrane (30) is electrically conductive over its entire underside.
  12. A membrane keyboard according to claim 11, characterised in that the membrane (30) is made of a homogeneous, electrically conductive material.
EP87105500A 1986-04-17 1987-04-14 Layered keyboard Expired - Lifetime EP0241906B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE8610553U DE8610553U1 (en) 1986-04-17 1986-04-17 Membrane keyboard
DE8610553U 1986-04-17

Publications (3)

Publication Number Publication Date
EP0241906A2 EP0241906A2 (en) 1987-10-21
EP0241906A3 EP0241906A3 (en) 1989-12-27
EP0241906B1 true EP0241906B1 (en) 1992-09-30

Family

ID=6793782

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87105500A Expired - Lifetime EP0241906B1 (en) 1986-04-17 1987-04-14 Layered keyboard

Country Status (4)

Country Link
US (1) US4771143A (en)
EP (1) EP0241906B1 (en)
DE (2) DE8610553U1 (en)
FI (1) FI84671C (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE8610553U1 (en) * 1986-04-17 1986-05-28 Wilhelm Ruf Kg, 8000 Muenchen Membrane keyboard
EP0322514A3 (en) * 1987-12-30 1990-09-12 Hewlett-Packard Company Keyboard switch system
JP2522514B2 (en) * 1988-03-10 1996-08-07 シャープ株式会社 Operation input device
US5220136A (en) * 1991-11-26 1993-06-15 Elographics, Inc. Contact touchscreen with an improved insulated spacer arrangement
GB2345193B (en) 1998-12-22 2002-07-24 Nokia Mobile Phones Ltd Metallic keys
US6657146B1 (en) 2000-03-28 2003-12-02 Thomson Licensing, S.A. Button ball and alignment rib
JP4359812B2 (en) * 2002-07-08 2009-11-11 日本電気株式会社 Switch-integrated casing and electronic device having the same
US6639165B1 (en) * 2002-10-28 2003-10-28 Delphi Technologies, Inc. Multiple contact fluid pressure switch
GB0403854D0 (en) * 2004-02-20 2004-03-24 Pelikon Ltd Switches
US7619176B2 (en) * 2006-02-13 2009-11-17 Nec Corporation Switch and electronic equipment having the same
JP4598721B2 (en) * 2006-05-22 2010-12-15 シャープ株式会社 Operation key parts
US20110290628A1 (en) * 2010-05-31 2011-12-01 Sunrex Technology Corp Membrane keyboard with parts being fixedly secured together

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3600528A (en) * 1969-09-25 1971-08-17 Lematex Corp Multiple switch construction
US4128744A (en) * 1977-02-22 1978-12-05 Chomerics, Inc. Keyboard with concave and convex domes
JPS56128523A (en) * 1980-03-11 1981-10-08 Matsushita Electric Ind Co Ltd Method of producing keyboard switch
US4375585A (en) * 1981-01-08 1983-03-01 Atari, Inc. Deformable switch keyboard
FR2541523B1 (en) * 1983-02-17 1985-10-25 Metallo Ste Fse MATRIX PRESELECTOR
JPS6059429U (en) * 1983-09-30 1985-04-25 アルプス電気株式会社 switch device
US4489227A (en) * 1984-01-11 1984-12-18 Sheldahl, Inc. Back lighted, full travel push button membrane keyboard
DE8610553U1 (en) * 1986-04-17 1986-05-28 Wilhelm Ruf Kg, 8000 Muenchen Membrane keyboard

Also Published As

Publication number Publication date
DE3781924D1 (en) 1992-11-05
EP0241906A2 (en) 1987-10-21
US4771143A (en) 1988-09-13
EP0241906A3 (en) 1989-12-27
FI84671B (en) 1991-09-13
FI871679A (en) 1987-10-18
FI84671C (en) 1991-12-27
DE8610553U1 (en) 1986-05-28
FI871679A0 (en) 1987-04-15

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