Browse Prior Art Database

Capacitive Keyboard Unit

IP.com Disclosure Number: IPCOM000073823D
Original Publication Date: 1971-Feb-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Ecker, ME: AUTHOR

Abstract

The drawing shows a key 2 which can be depressed to move a spring 3 into contact or proximity with a circuit module 4. Module 4 contains capacitance sensing circuits that respond to the proximity of spring 3 to produce a coded signal identifying the associated key 2. Module 4 is interconnected with other components of a keyboard by a circuit board 5.

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Capacitive Keyboard Unit

The drawing shows a key 2 which can be depressed to move a spring 3 into contact or proximity with a circuit module 4. Module 4 contains capacitance sensing circuits that respond to the proximity of spring 3 to produce a coded signal identifying the associated key 2. Module 4 is interconnected with other components of a keyboard by a circuit board 5.

Spring 3 is held between the inclined walls of a movable part 6 and a stationary frame part 8. A shaft 9 connects part 6 to key 2. When the key is depressed, the spring moves from the position shown in the solid line to the position of dashed line 10. Since the spring is more tightly curved in the dashed line position, it provides a force for restoring the key. The spring can be given a selected linear or nonlinear rate by providing the appropriate shape for frame part
8.

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