ZOOM LENS FOR PROJECTION AND PROJECTION IMAGE DISPLAY DEVICE

PROBLEM TO BE SOLVED: To provide a compact zoom lens for projection having a large zoom ratio of 1.4 or more, a large angle of view with a half angle of view of 30° or more at the wide-angle end, and a bright F-number of about 1.7, and providing satisfactory images.SOLUTION: A zoom lens for projecti...

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Bibliographic Details
Main Author TOBIUCHI KUNIYUKI
Format Patent
LanguageEnglish
Published 08.03.2012
Subjects
ACCESSORIES THEREFOR
APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES
APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM
CINEMATOGRAPHY
ELECTROGRAPHY
HOLOGRAPHY
OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS
OPTICS
PHOTOGRAPHY
PHYSICS
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Summary:PROBLEM TO BE SOLVED: To provide a compact zoom lens for projection having a large zoom ratio of 1.4 or more, a large angle of view with a half angle of view of 30° or more at the wide-angle end, and a bright F-number of about 1.7, and providing satisfactory images.SOLUTION: A zoom lens for projection includes, in order from an enlargement side to a reduction side, a first lens group G1 having negative refracting power, a second lens group G2 having positive refracting power, a third lens group G3 having positive refracting power, a fourth lens group G4 having negative refracting power, a fifth lens group G5 having positive refracting power, a sixth lens group G6 having positive refracting power, and a seventh lens group G7 having positive refracting power, and is substantially telecentric on the reduction side. Zooming is performed by individually moving the second to sixth lens groups G2 to G6 in the optical axis direction, and focusing is performed by moving the first lens group in the optical axis direction. The zoom lens for projection satisfies conditions (1) to (5).
Bibliography:Application Number: JP20100190707