Computer keyboard: Difference between revisions

Revision as of 19:24, 7 July 2024

Revision as of 06:14, 8 July 2024

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Plastic materials played a very important part in the development and progress of electronic keyboards. Until "monoblocks" came along, GE's "self-lubricating" [[Polyoxymethylene plastic|Delrin]] was the only plastic material for keyboard switch plungers that could withstand the beating over tens of millions of cycles of lifetime use. Greasing or oiling switch plungers was undesirable because it would attract [[dirt]] over time which would eventually affect the feel and even bind the key switches (although keyboard manufacturers would sometimes sneak this into their keyboards, especially if they could not control the tolerances of the key plungers and housings well enough to have a smooth key depression feel or prevent binding). But Delrin was only available in black and white, and was not suitable for keytops (too soft), so keytops use [[Acrylonitrile butadiene styrene|ABS]] plastic. However, as plastic molding advanced in maintaining tight tolerances, and as key travel length reduced from 0.187-inch to 0.110-inch (4.75 mm to 2.79 mm), single-part keytop/plungers could be made of ABS, with the keyboard monoblocks also made of ABS.

In common use, the term "mechanical keyboard" refers to a keyboard with individual mechanical key switches, each of which contains a fully encased plunger with a spring below it and metallic electrical contacts on a side. The plunger sits on the spring, and the key will often close the contacts when the plunger is pressed halfway. Other switches require the plunger to be fully pressed down. The depth at which the plunger must be pressed for the contacts to close is known as the activation distance. Analog keyboards with key switches whose activation distance can be reconfigured through software, optical switches that work by blocking laser beams, and Hall Effect keyboards that use key switches that use a magnet to activate a hall sensor are also available.

Some keyboardkeyboards, allowscalled pressure-sensitive, allow varying input basedaccording onto the distance pressed, akinanalogously to the [[analog joystick]], and it's sometimes called a pressure-sensitive keyboard.<ref>{{cite web|url=https://arstechnica.com/gadgets/2022/03/razers-huntsman-mini-analog-keyboard-has-pressure-sensitive-mechanical-keys/ |title=Razer adds joystick-like control to a small mechanical keyboard |website=Arstechnica |date=4 March 2022 |first=Scharon |last=Harding }}</ref>

=== Control processor ===