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US Patent 6084720 - Small-sized real image mode zoom finder
US Patent Issued on July 4, 2000
Estimated Patent Expiration Date:
October 27, 2018Estimated 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.
Estimated Patent Expiration Date:
October 27, 2018Estimated 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.AbstractA real image mode zoom finder includes, in order from the object side, an objective optical system with positive refracting power having a first lens unit with negative refracting power, a second lens unit with positive refracting power, a third lens unit with positive refracting power, and a fourth lens unit with negative refracting power; an image erecting system for erecting an intermediate image formed by the objective optical system; and an ocular optical system with positive refracting power. In this case, each of lens units constituting the objective optical system is constructed with a single lens, and the object-side surface of the first lens unit is configured to be concave. Moreover, the objective optical system satisfies the following condition:2.5<T(R2) <5.7where T(R2) is a combined longitudinal magnification ranging from the second lens unit of the objective optical system to the intermediate image at the telephoto position of the finder. | InventorAssigneeApplicationNo. 179320 filed on 10/27/1998US Classes:359/676, With variable magnification (e.g., zoom type)359/422, Variable magnification359/432, Variable magnification359/686, Four groups396/379, Zoom396/382Lens detailField of Search359/676, With variable magnification (e.g., zoom type)359/677, Optically compensated359/678, Prism lens type359/679, With fixed conjugates359/680, Reverse telephoto359/681, Having eight or nine components359/682, Having seven or less components359/683, With mechanical compensation359/684, Other than first group moves for focusing (internal focus type)359/685, Nonlinear variator/compensator movements359/686, Four groups359/381, Imaging elements movable in and out of optical axis359/385, Illuminator359/366, Concave, convex combination359/384, With rotatable adjustment359/389, With illumination and viewing paths coaxial at the image field359/426, Internal focusing359/435, Repetitious lens structure359/368, Microscope359/374, Plural oculars359/375, Binocular359/390, With illuminator support359/415, Oculars rotate about separate axes359/380, Variable magnification359/422, Variable magnification359/433, With tilted lens or tilted image plane359/372, With plural optical axes359/362, COMPOUND LENS SYSTEM359/434, With relay359/423, With relay359/363, With image recorder359/371, Using polarized light359/398, Specimen cavity or chamber359/409, Body supported or with handle359/407, Binocular359/421, Selectable magnification359/399, Telescope359/367, Right angle inspector359/431, With prism or U-shaped optical path359/393, With plural transverse movements359/382, Entire microscope adjustable along optical axis359/383, Focus adjustment359/369, With viewed screen359/364, With curved reflective imaging element359/432, Variable magnification359/428, With reticle359/373, Side-by-side fields359/414, Spacing of optical elements axially adjustable359/413, Oculars swing about central axis359/405, With mechanical adjustment359/416, Spacing of optical elements axially adjustable359/427, With reticle359/417, Spacing of optical elements axially adjustable359/420, Plural magnification in same viewing field359/401, With image anti-rotation359/370, Interference359/408, Foldable or collapsible359/406, Extensible structure359/392, Adjustable along optical axis359/388, With optical switching means359/419, With plural optical axes359/396, Transparent slide359/418, Spacing of optical elements axially adjustable359/404, Binocular359/397, Reference lines or grids359/412, With adjustable interocular distance359/429, With line of sight adjustment359/395, With temperature control359/410, With focusing means359/365, Two or more in a series359/387, With annular lighting structure359/402, Periscope359/377, With single or parallel objectives359/378, For viewing stereo pairs359/379, Spacing of optical elements axially adjustable359/425, Focusing or relatively sliding barrels359/394, With turntable359/400, With viewed screen359/430, Equatorial mount359/376, Stereoscopic359/386, Using polarized light359/411, With adjustable interocular distance359/424, With reticle359/391, Stage or slide carrier359/403, With plural optical axes396/379, Zoom396/380, Variable size of mask opening396/381, Variable orientation of finder image396/382Lens detailExaminersPrimary: Epps, GeorgiaAssistant: Spector, David N. Attorney, Agent or FirmUS Patent References5920427Keplerian variable magnification finderIssued on: 07/06/1999 Inventor: Ogata Foreign Patent References
International ClassesG02B 015/14G02B 023/00 G03B 013/06 G03B 013/10 Foreign Application Priority Data1997-10-28 JP |
