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:
Jan. 04, 1977
Filed:
Nov. 20, 1975
Allan S Way, Irvine, CA (US);
Stanley L Pratt, Riverside, CA (US);
Beckman Instruments, Inc., Fullerton, CA (US);
Abstract
A tracking accuracy control system for a spectrophotometer utilizing stepper motors for controlling the wavelength drive and chart drive system. An exact ratio between the wavelength drive motor and chart drive motor is maintained under variable speed conditions by utilizing an error signal which normally operates the reference beam attenuator, this error signal being transmitted through an absolute value circuit to produce a voltage whose magnitude is the absolute value of the error signal. This absolute value is then transmitted through a fast attack, slow release hold-over circuit to control a voltage controlled oscillator in such a way as to reduce wavelength scan speed in an amount proportional to the error while simultaneously controlling chart speed in an exact ratio to the scan speed. The output of the voltage controlled oscillator is a pulse train having a frequency proportional to the magnitude of the absolute value of error signal.