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:
Feb. 12, 1991
Filed:
Dec. 27, 1988
Yoshiaki Hirao, Habikino, JP;
Ryuichiro Kuga, Katano, JP;
Masayuki Yoneyama, Takatsuki, JP;
Shusuke Ono, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A zoom lens driving apparatus always detects a position of an image magnification varying lens section, and drives the image magnification varying lens section in accordance with a preset relationship between the position of the image magnification varying lens section and a zoom driving speed in such a manner that the driving speed becomes higher on one side, where the focal length of the zoom lens corresponding to the position of the image magnification varying lens section is small, than on another side where the focal length is large. Accordingly, the amount of focal shift, which in the zoom lens of the inner focusing system would otherwise abruptly increase with increasing focal length, is significantly suppressed, so that an auto focus adjusting mechanism or a focus correcting device effective during zooming, provided in the zoom lens, can function satisfactorily as to follow the focal shift of the zoom lens, whereby the lens control of a superior response can always be achieved.