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:
Nov. 13, 1990
Filed:
Jan. 09, 1989
Philip A McGee, Beltsville, MD (US);
NIRSystems Incorporated, Silver Spring, MD (US);
Abstract
An optical grating is oscillated at a high rate to scan a narrow wavelength band of light through the spectrum dispersed by the grating. The grating is connected integrally with the rotor of a motor, which is energized to oscillate its rotor between selected limits. The direction of rotation of the motor is controlled by an H drive circuit connected to a coil of the motor. The speed of the motor is controlled by a pulse train applied to the motor coil through the H drive. The pulse train has a duty cycle varying inversely with the motor speed. The duty cycle of the pulse train is controlled by a counter which is connected to count high frequency pulses and which is reset each time the grating rotates through an angular increment. The limits of the oscillation of the grating and the rate of rotation of the grating between the limits are selectively variable. Output readings from the spectrophotometer are taken at equal angular increments of the grating and these readings are converted to values occurring at equal wavelength increments by a computer.