Three centuries ago, if you asked someone whether they think writing a letter can be achieved without using a pen, they’d think you have lost your mind.
Three centuries ago, if you asked someone whether they think writing a letter can be achieved without using a pen, they’d think you have lost your mind, You’d be considered a lunatic, a maniac even. But ever since the invention of typewriter in late nineteenth century, writers, philosophers and political activists have leveraged it to their full extent. Nowadays, desktop computers and laptops have become a major part of our life.
A keypad is a set of buttons, which bear different alphabets and digits, and are arranged, in a specific set. A keypad is not limited to just personal computers, it can also be found on microwave controllers, calculators, vending machines, digital locks, Point of Sale devices, etc. The most commonly used format of a keypad is E.161, which defines the arrangement of 26 alphabets of English on 12 key telephone keypad.
Silicon Rubber Keypad
A silicon keypad (which is also called elastomeric keypad) is a low-priced and dependable switching solution, which is utilized widely in both shopper and modern electronic items. It provides a three dimensional operating surface, which is highly desirable by its users. The technology used in rubber keypads is the compressed mold technique, where properties of silicon are used to make calculated webbing around a switch focus.When it is fancied to do an electronic switch, a carbon pill or the gold pill is set at switch focus base.
When the switch is pressed, the webbing starts deforming uniformly producing a material reaction. When pressure is removed, positive feedback is produced as the webbing returns to its neutral position. The conventional use of silicone rubber keypad can be found in remote controls, mobile handsets (remember the old Nokia phones) and electronic toys. Nowadays, these keypads find their use in switch mechanisms within automobiles, like window lifts, music controls, etc.
Membrane keypads are like the modern and sleeker version of rubber keypads. In a membrane keypad, keys are not separate, ‘moving’ parts but rather pressure sensitive spots, which have outlines and symbols engraved over a flat and flexible surface. As opposed to the rubber keypads, no or very little tactile feedback is used in membrane keypads. Due to this reason, error free blind typing is exceeding difficult in its case. Although modern PC keyboards offer membrane keypads with dome switches to provide tactile feedback.
A membrane keyboard consists of three layers, two of which contain conductive traces.The center layer is a spacer layer containing holes for the existence of the ‘keys’. In its natural state, the switch is considered to be open as the current cannot pass between the top and bottom layer.
When pressure is applied with your finger, a bridge is formed between the top and bottom layer through your skin.As we are well aware of the dielectric and conducting properties of human body, it will not be difficult to conclude how the current flows and the parent device registers the key. It is usually used in Industrial controls, medical equipment, telecommunications apparatus, etc.
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