Keyboard with reflected light beam finger detection

摘要

A keyboard operates by having a light beam reflected off a finger. When present, as indicated by the presence of the reflected light beam, the keyboard key location is sent to a PC or other device. The keyboard can be used in bright sunlight and total darkness. The keyboard has a one piece planar top surface with no opening or microbial (bacterial or viral) harbors.

主权项

1. A keyboard with reflected light beam finger detection, comprising:
a plurality of substantially transparent areas; a plurality of light emitters and a plurality of light detectors, each light emitter being paired with a light detector whereby emitted light from the light emitter of a pair is intended to be reflected to the light detector of the pair, and wherein pairs of light emitters and light detectors are aligned with and disposed below each of said substantially transparent areas; a plurality of visible light emitters aligned with and disposed below each of said substantially transparent areas; a microprocessor including a dark ambient value stored for each of said plurality of light detectors, said dark ambient value being substantially equal to a value detected by said light detector at said substantially transparent areas when a finger encompasses said substantially transparent area thereby blocking ambient light to said light detector at said one of said plurality of said substantially transparent areas, said microprocessor being configured to scan said plurality of light detectors and to determine a detected value for each of said plurality of light detectors, wherein when each of said plurality of light detectors is scanned and after said microprocessor determines at least one light detector has a detected value substantially equal to said dark ambient stored by said microprocessor, then an emitter paired with said light detector is turned on, wherein
if a value detected by said light detector when said emitter is turned on is substantially equal to said dark ambient value stored by said microprocessor this identification is equated to no finger being detected, andif said value detected by said light detector when said emitter is turned on is substantially different from said dark ambient value this identification is equated to a finger being detected, and said microprocessor provides a key code representative of a location to a host.