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:
Dec. 25, 1984
Filed:
Oct. 20, 1982
Fujio Moriguchi, Kanagawa, JP;
Fuji Xerox Co., Ltd., Tokyo, JP;
Abstract
An apparatus for exciting a step motor such as a step motor employed as a drive source for conveying original documents in a reading device such as a facsimile system. To vary the feed pitch in the auxiliary scanning direction of the original, staircase waveform exciting currents are applied through A-phase and B-phase exciting coils of the step motor. The apparatus of the invention provides for equal step sizes of the two waveforms and waveforms which are precise complements of one another. Currents flowing in the two exciting coils are sensed and voltages representing the sensed currents are divided in ratios determined by division ratio control signals read from a ROM. The divided signals are compared with a reference signal to provide pulse drive signals of constant currents during each step.