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:
Apr. 29, 1997
Filed:
May. 23, 1995
Tetsuhito Ikeda, Kawasaki, JP;
Canon Kabushiki Kaisha, Tokyo, JP;
Abstract
In this invention, a stepping motor control system includes a PWM unit for generating a PWM signal corresponding to a changing duty ratio, a low-pass filter for receiving the PWM signal from the PWM unit, and converting staircase voltage levels represented by the changing duty ratio of the PWM signal into a smooth, substantially continuous voltage signal, and an arbitrary current value setting type constant current driving circuit, which receives the voltage signal from the low-pass filter, excites the excitation coil of the stepping motor by a current value set in correspondence with the voltage signal, and maintains the current value set in correspondence with the voltage of the voltage signal. Thus, a stepping motor control system which can eliminate wasteful power consumption and can realize high-precision, constant-speed rotation can be provided. When the stepping motor control system is used for driving a carriage of a recording apparatus, a recording apparatus which is free from printing nonuniformity and can achieve power saving can be provided.