Membrane Keypads
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Input Systems

knitter-switch Overview knitter-switch is one of Europe’s leading knitter-switch continues to design new manufacturers of switches. Since its foundation in 1966, switching solutions, employing the latest technologies knitter-switch has remained at the forefront of and materials while ensuring compliance to continuously switch technology and now provides an unrivalled range evolving legislation. We offer the most complete range of of switching solutions from basic toggle types to tact switches available to design engineers and bring the switches and membrane and rubber keypads for today’s...

Input Systems Membrane Keypads • Graphic overlay only or full switching membrane • Metal, polydome or pushgate contacts • Tactile or non-tactile feel • Integrated touch screens, encoder, LEDs and other components • LCD windows • ESD/RFI shielding • Insertable legend options Rubber Keypads • Backlighting options • Various coatings eg epoxy, polyurethane • Harder rubber options to give ‘plastic’ feel • Various travel /operating force options • Combination with tactile switches • Wide variation of colours and designs • Plastic key tops available

Rubber Keypad Design Basic Construction Illustration Life Test Section 1 Top Surface Optional Colour / Shore A Operating life depends on: • Soft Material ... 50 Shore is preferred. • Low Stroke ... less than 1 mm. • Angle (as part A illustrated above) ... 40-degree is recommended. • Length of side-wall (as part B illustrated above) • Thickness of side-wall (as part C illustrated above) ... determined by key structure. The thicker the web, the higher the operating force. Mounting Hole Side-Wall (Web) Tolerance Requirement of Silicone Rubber Key Dimensions: 0 ~ 10 mm 10 ~ 20 mm 20 ~ 30 mm 30...

Rubber Keypad Design Some Special Design Illustrations 2. Push or pull thru to anchor keypad to PCB 1. Different shorehardnesses in the basic keypad and key Different hardnesses and colours available Conductive pill 3. Back lighting – option 1 Front panel Conductive pill Rubber Conductive pill 4. Squared key top design with LED light pipe 5. Back lighting – option 2 6. Control of travel distance Plastic key top Conductive printed Light pipe Conductive pill Rubber Special Design for Construction Ideas 2 Tear Line Guideline for Assembly Design A a A & B : dimensions of plastic a & b :...

Membrane Keypad Structure Overlay / Upper Circuit • Flat or Embossed Buttons • Conductive Carbon or Silver Printed Contacts Termination to suit Application Metal Domes or Polydome Tactile Lower Circuit and LEDs embedded Insulation Printing Adhesive Tape PushGate Graphic overlay Magnet Armature Substrate with Printed Circuit Flat Type (POLYDOME, Non-Tactile) Graphic overlay Upper spacer with adhesive Printed circuit Back adhesive

Membrane Switch Structure Tactile Type POLYDOME Embossed graphic overlay with upper circuit Spacer with adhesive Lower circuit Back adhesive METAL DOME Embossed graphic overlay Mounting spacer with adhesive Mounting spacer Metal dome Lower spacer with adhesive Lower circuit Back adhesive Typical Specification METAL DOME Operating voltage Breaking current Max. initial contact resistance Operating temperature Actuation force

Capacitive keypads Capacitive keypads are wear-free input systems with no moving parts, which are operated by touch (sensor) without pressure. An inexpensive alternative to the touch screen, they consist of an actual keypad with sensor surfaces arranged in fixed positions and a controller IC. Spatially, the controller can be both assigned to the keyboard or located on the PCB at the equipment end. The design in terms of shape and colour scheme is essentially restricted only by the type of surface material Top layer (PET, Single side hard coating) Bottom layer (ITO, Paste to FPC with silver...

Functional units with touch screens Touch screens operating according to resistive or capacitive principles are an obvious choice for applications in which, as in a monitor display, a variety of input fields (differing in terms of number, size, arrangement) are designed to be active and a robust, closed surface is required. knitter-switch supplies complete customized functional units in which touch screens, optionally in combination with film keypads, are integrated in modules such as front panels. Resistive touch screens These consist of a carrier layer (glass, film) and a surface layer...

Layout Inquiry Please sketch out your keypad layout and return to us (See back page for address details)

Keypads Inquiry Form Company Department Attention Address Postcode Phone Membrane Requirements Graphic Layer Overall size Are embedded LEDs required What finish is required (matt, gloss or selective texture) Number and colour Will a separate tail be required Are windows required Size Tail position and length Position of tail – exit from side and rear Do they need to be tinted Type of connector (if required) Is embossing required Pillow or rim If ZIF connector being used, get type for ref. Switches Number Any special features required Insert legends If tactile: polydome or metal dome...

Input Systems elektrotechnische erzeugnisse · Knitter & Co. KG