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. 27, 1997
Filed:
Oct. 20, 1994
Keiji Kunishige, Hachioji, JP;
Minoru Hara, Hachioji, JP;
Olympus Optical Co., Ltd, Tokyo, JP;
Abstract
The present invention is directed to a zoom encoder for detecting an amount of angular movement and a direction of angular movement of a cam ring which is angularly moved about an optical axis of a photographing optical system to change a focal length of the photographing optical system. The zoom encoder is characterized by comprising a pulse generator of non-contact type for generating pulse signals in accordance with the angular movement of the cam ring that serves as a drive for changing the focal length of the photographing optical system, a counter for selectively adding or subtracting the pulse signals in accordance with the direction of angular movement of the cam ring, a position detector for detecting a predetermined position signal at least in the vicinity of a wide angle end and in the vicinity of a telephoto end of the focal length, a count-value modifier for modifying the count value of the counter to a predetermined value in accordance with a change in an output from the position detector, and a zoom-information detector for producing zoom information on the basis of the output from the counter.