Absolute position detecting method and apparatus therefor

Details Absolute position detecting method and apparatus therefor Absolute position detecting method and apparatus therefor

1990-07-31

1992-02-25

Nelms, David C.

Radiant energy

Photocells; circuits and apparatus

Optical or pre-photocell system

25023116, 341 13, G01D 534

Patent

active

050916432

ABSTRACT:
A method and apparatus for simultaneously detecting and comparing a plurality of upper patterns indicative of Gray code patterns and having greater pattern pitches and a plurality of lower patterns indicative of pure binary code patterns and having smaller pattern pitches to correct the upper pattern detection data and thereby detect an absolute position. An absolute position detecting apparatus includes a code plate formed with a plurality of upper patterns and a plurality of lower patterns which are arranged radially along the periphery of a rotating body; a mask arranged at a position opposite to the code disc and having a plurality of upper slits and a plurality of first slits and a plurality of second slits which are formed to correspond to the lower patterns and having a 90-degree phase difference therebetween; a laser light source arranged at a position on the opposite side of the code plate to the mask to illuminate the code plate to form pattern projection images on the mask; a light detector for detecting the pattern projection images to detect positional alignment between the patterns and the slits; and data processing circuit for correcting detected data of the upper patterns by referring to those of the lower patterns.

REFERENCES:
patent: 4443788 (1984-04-01), Breslow
patent: 4465928 (1984-08-01), Breslow
patent: 4621256 (1986-11-01), Rusk
patent: 4654636 (1987-03-01), Rusk

Affiliated with

Also associated with

Rating

Absolute position detecting method and apparatus therefor does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Absolute position detecting method and apparatus therefor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absolute position detecting method and apparatus therefor will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1894800