The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 1976
Filed:
Jan. 10, 1974
Albin Kenneth Johnson, Boulder, CO (US);
Iomec, Inc., Santa Clara, CA (US);
Abstract
An electronic feedback control system which compensates for errors in the position information signals output from a pair of photodetectors in a linear motion position transducer, such as used to locate a read-write head over an addressed track in a magnetic disc file system. The control circuitry sums the instantaneous values of the time varying photodetector outputs to produce a combined output signal. The peak positive value of the combined signal is determined and compared with a preselected reference value. An error signal proportional to the difference between the peak and reference values is generated and amplified to produce a correction signal. The correction signal is then applied to the variable energization input of the light source which illuminates the photodetector pair. The correction signal reduces the error signal toward zero by causing the light source to compensate for error in the photodetector output signal.