Device for adjusting the diopter setting of a finder assembly
Patent 5621568 Issued on April 15, 1997. Estimated Expiration Date: 
April 15, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
April 15, 2014. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3205774 View finder of variable magnification Finding device of variable magnification Finder of variable magnification Variable magnification viewfinder Zoom finder of real image type 5117247 Zoom finder Real image type variable magnification viewfinder optical system Patent #: 5257129 Inventors
AssigneeApplicationNo. 882958 filed on 05/14/1992US Classes:359/432, Variable magnification359/676, With variable magnification (e.g., zoom type)359/684, Other than first group moves for focusing (internal focus type)359/820With temperature compensation or controlExaminersPrimary: Nguyen, ThinhAttorney, Agent or FirmForeign Patent References
International ClassesG02B 023/00G02B 015/14 G02B 007/02 820 Foreign Application Priority Data1991-05-17 JPAbstractA mechanism for adjusting the diopter setting of a finder assembly which has an objective optical system and an eyepiece optical system, includes an object side image forming position adjusting device which adjusts the position where an image is to be formed by the objective optical system. The mechanism effectively compensates for any change that occurs in the position where an image is formed by the objective optical system due to temperature or humidity variations. Thus, the problem of plastic lenses having their focal lengths extended in a hot and humid environment is solved by the invention.Field of SearchBy nonmovable driving element (e.g., piezoelectric, magnetostrictive)Produced by coating or lamina Selectable magnification Variable magnification With relay With reticle Variable magnification With prism or U-shaped optical path With tilted lens or tilted image plane With relay With focusing means Spacing of optical elements axially adjustable With plural optical axes With variable magnification (e.g., zoom type) Reverse telephoto Three groups + - + Arrangement - + + + Arrangement + - Arrangement Motor driven Condition responsive Auto focusing Having cam device Cam groove type Cam ring type or zoom ring type With adjustment lock With specified mount Having detail of barrel With macro type focusing With specific ring means Lens mounts | |
