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. 19, 1988
Filed:
Oct. 28, 1986
Shigeo Sato, Tokyo, JP;
Yutaka Yoshida, Tokyo, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A shutter driving apparatus drives a programmed shutter with a stepping motor, by using a driving current pulse whose waveform has a leading half that gradually increases in amplitude and a trailing half having an amplitude smaller than the peak value of the pulse. At each rotary stage of the stepping motor, a smooth starting operation can be ensured without any adverse inertial effect at the start or end of rotation, the stepping motor being temporarily driven at low speed at the end of each pulse. In the case of an aperture priority exposure control using a programmed shutter, disadvantageous ripple motion of the shutter sectors is eliminated, thus enabling high precision exposure control.