Fujinon Corporation

Honda Motor Co., Ltd.

Fujifilm Corporation

Fujinon Corporartion

Hiroshi Yamada

Akiko Nagahara

Kimiaki Nakazawa

Chikara Yamamoto

Yukiko Nagatoshi

Shoji Yamamoto

Mikio Uchiyama

Daisuke Tokumura

Hiroyuki Maeda

Toshiyuki Kubota

Masaru Hisadomi

Toshihiko Kamio

Yuuji Watanuki

A zoom lens for projection includes a first negative lens group, a second positive lens group, a third positive lens group, a fourth lens group, and a fifth positive lens group, which are sequentially arranged from the magnification side of the zoom lens. The first lens group and the fifth lens group are fixed, and the second lens group, the third lens group and the fourth lens group move along the optical axis of the zoom lens when magnification of the zoom lens is changed. Each of the first lens group and the second lens group is composed of two lenses. Each of the third lens group and the fifth lens group is composed of a positive lens, and the fourth lens group is composed of five lenses. Further, the reduction side of the zoom lens is telecentric.

Zoom lens for projection and projection-type display apparatus

A vehicle number plate that allows a steering damper to be disposed without impairing the functions of the number plate, and is less susceptible to an effect of cross wind. The vehicle includes a front fork, which suspends a front wheel, disposed steerably on a head pipe on a vehicle body and a steering mechanism including a handlebar mounted on the front fork. The number plate is marked with a competition identification number and is disposed at a front portion of a fork bridge including a top bridge and a bottom bridge to connect left- and right-hand portions of the front fork. In the vehicle, the steering damper is disposed between the head pipe and the bottom bridge. The number plate includes a protruded portion that protrudes forwardly at a center thereof and narrows toward a lower portion, the lower portion covering an area forward of the steering damper.

Vehicular number plate

A projection zoom lens is provided and includes: in order from the magnification side, a positive first lens group performing focusing with being fixed during power-varying and having a focusing function; a negative second lens group, a negative third lens group, and a positive fourth lens group, which are moved with correlation during the power-varying; and a positive fifth lens group Gfixed during the power-varying. An aperture diaphragm is fixed between the fourth lens group and the fifth lens group during the power-varying. In addition, the expression of 1.7&#x3c;Bf/f&#x3c;3.0 is satisfied, where f is a focal length of the whole system, and Bf is a back focal length (air conversion distance) of the whole system.

Projection zoom lens and projection type display device

A projection zoom lens is provided and includes: in order from the magnification side, a negative first lens group performing focusing with being fixed during power-varying; a positive second lens group, a positive third lens group, a positive fourth lens group, a positive fifth lens group, which are moved with correlation; and a positive sixth lens group fixed during the power-varying. An aperture diaphragm is moved between the fourth lens group and the fifth lens group during the power-varying to keep Fno constant in the whole power-varying region. In addition, the expression of 1.7&#x3c;Bf/f&#x3c;3.0 is satisfied, where f is a focal length of the whole system, and Bf is a back focal length (air conversion distance) of the whole system.

Disposed in order from a magnification side are a negative first group which is fixed during zooming to effect focusing, second to fifth groups of positive refractive power which move with mutual relationship during magnification variation, and a fixed sixth group. A negative lens made of a glass material which has an anomalous dispersion property and which has 70 or more in Abbe number is disposed in the first lens group. A positive lens made of a glass material which has an anomalous dispersion property and which has 70 or more in Abbe number is disposed in the third group located closer to a reduction side than a diaphragm. The negative lens and the positive lens are cemented to their adjacent lenses, respectively. Also, bf/fw &#x2267;2.7 is satisfied where bf denotes a back focus, and fw denotes a focal length of the entire system at a wide-angle end.

Projection type zoom lens and projection type display apparatus

A negative first group Gis fixed when a power of the projection zoom lens varies and has a focusing function. A positive second group G, a positive or negative third group G, a positive fourth group Gand a positive or negative group Gmove with a mutual relationship. A sixth group Gfunctions as a relay lens. The fifth group Gincludes a cemented lens formed by cementing a negative meniscus lens Lhaving a convex surface directed to the magnification side, a negative lens Land a positive lens Lin order from a magnification side, and a positive lens Lhaving a convex surface directed to a reduction side. Also, an expression |F|/F&#x3e;4.5 is satisfied where F denotes a focal length of the projection zoom lens at a wide-angle end and Fdenotes a focal length of the fifth group.

Projection zoom lens and projection-type display device

A projection lens includes, in order from a magnification side, a first lens group, a second lens group and a third lens group. The first lens group includes, in order from the magnification side, a negative lens whose lens made of a non-resin, a plastic lens at least one surface of which is aspheric and a positive lens. The second lens group includes a plastic lens at least one surface of which is aspheric, a positive lens and a negative lens. The third lens group includes a positive lens. The following conditional expressions are satisfied;1.0&#x3c;&#x2266;1.82.0&#x3c;1/2.0&#x3c;2/where Bf denotes a air-conversion back focus of the entire system, f denotes a focal length of the entire system, f1 denotes a focal length of the first lens group and f2 denotes a focal length of the second lens group.

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Saitama, Japan

Hiroshi Yamada