| 摘要 |
A self-calibrating key sensor system is constituted by an optical modulator (40), optical position transducers (14), a data accumulator (61) and a data analyzer (62), and the optical modulator (40) has a gray scale section (41) to produce a key position signal (yk(s)) varied together with the keystroke and an absolute data section (42) to produce a calibration signal (yk(p)) representative of a strictly adjusted distance (D) between transparent areas (42a1/42a2) of the absolute data section (42); the data accumulator (61) accumulates discrete values of the calibration signal (yk(p)) and discrete values of the key position signal (yk(s)) together with the sampling time, and the data analyzer (62) determines the gradient of the key position signal (yk(s)) on the basis of peaks (P1) of the calibration signal (yk(p)) produced at both ends of the strictly adjusted distance (D) so as to estimate the true distance between the rest and end positions (RP, EP). |
