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:
May. 21, 1996
Filed:
Apr. 07, 1994
Hiroshi Kawamura, Tokyo, JP;
Norikatsu Inoue, Tokyo, JP;
Kunio Nakazato, Tokyo, JP;
Akihito Nakayama, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
A camera lens barrel having a first grouped lens, a movable second grouped lens for variable magnification, a third grouped lens, and a fourth grouped lens, which are respectively arranged along an optical axis, and accommodating a drive system for the first to fourth lenses. The camera lens barrel is provided with a stepping motor, a control device capable of respectively carrying out in a low speed drive mode at least micro step drive control and pulse drive control of the stepping motor, and a moving mechanism for converting rotation of the stepping motor into movement of the second grouped lens along the optical axis. The control device carries out position control of the second grouped lens according to a control quantity of the stepping motor. As the stepping motor is driven under the micro step drive control, the generation of noise and vibration can be greatly suppressed as compared with a conventional lens barrel employing a DC motor as a drive source.