Fuji Photo Optical Co., Ltd.

Fuji Photo Film Company, Limited

Fujinon Corporation

Other

Fujifilm Corporation

Kazunori Ohno

Michio Cho

Hideo Kobayashi

Kazuhiko Onda

Yoichi Iwasaki

Shigenori Goto

Katsuji Ozawa

Hiroshi Ohmura

Yasuhiko Tanaka

Yoshikazu Doi

Yutaka Sakai

Takao Koda

Hiroshi Hara

Takashi Suzuki

Yoshihiro Fujita

Hitoshi Miyano

Takayuki Noda

Seimei Ushiro

Tsutomu Tanaka

Hiroshi Komatsuzaki

Seiji Asano

Junichi Takagi

Yukio Noguchi

Yasunobu Kayanuma

Masayoshi Hirai

Masao Shoji

Nobuyuki Shirie

An image pickup lens includes a first lens having a positive meniscus shape convex toward an object side, a second lens disposed on an image side of the first lens and has a meniscus shape convex toward the image side, and an aperture stop disposed on the object side of the image side surface of the first lens, and satisfies conditional expressions given below, in which f is a focal length of the entire system, Ris a paraxial radius of curvature of the object side of the first lens, Ris a paraxial radius of curvature of the image surface of the first lens, and DD is a distance on the optical axis between the first and second lenses: 0.45&#x3c;R2/R3&#x3c;0.66; and 0.05&#x3c;DD/f&#x2266;0.117.

Image pickup lens, image pickup apparatus, and portable terminal device

On condition that a first lens group adopts at least one plastic lens; a second lens group adopts at least any two adjacent plastic lenses; the first lens group monotonously moves from an object side to an image plane side in a zooming; the second lens group monotonously moves from the image plane side to the object side; wherein fw/fpi represents a ratio of refractive power of the entire system achieved at a wide angle end to refractive power of the respective lenses; Prepresents a total of fw/fpi of the plastic lenses of the first lens group; and Prepresents a total of fw/fpi of the plastic lenses of the second lens group, the following conditional expressions &#x2212;0.22&#x3c;P&#x3c;&#x2212;0.01 and &#x2212;0.15&#x3c;P&#x3c;&#x2212;0.03, are both fulfilled.

Variable power optical system and imaging device

To provide a lens system advantageous for downsizing a moving group and suitable for large aperture ratio formation and ultra telescopic formation while maintaining an excellent optical function from a long distance to a close range. A first lens group having a positive refracting power, a second lens group having a negative refracting power, a third lens group having a positive refracting power, and a fourth lens group having a negative refracting power are provided in order from an object side. The first lens group includes a first sub group and a second sub group. The second sub group is provided with a refracting power stronger than that of the first sub group and a following condition equation is satisfied.1.5&#x3c;11&#x3c;2.2&#x2003;&#x2003;(1)

Telephoto lens

A zoom lens is provided and has: a first lens of a negative lens; a second lens of a positive lens; an aperture stop; a third lens of a negative lens; and a fourth lens of a positive lens in this order from an object side of the zoom lens. A zooming operation of the zoom lens is performed by varying mutual distances among the first to fourth lenses, and the zoom lens satisfies specific conditional expressions.

Zoom lens

A standard photographic lens is disclosed that includes a front lens group, a diaphragm stop, and a rear lens group, in order from the object side. The front lens group is formed of a negative meniscus lens with its convex surface on the object side, and a positive meniscus lens with its convex surface on the object side. The rear lens group is formed of a third lens element of negative refractive power with a concave surface on the object side, a fourth lens element of positive refractive power with a convex surface on the image side, and a fifth lens element, of meniscus shape with its concave surface on the image side. Organic material is preferably used for the second and third lens elements. Various conditions are satisfied so as to provide a lens having a bright image with favorably corrected aberrations.

Standard photographic lens

A Gaussian lens for photography includes, in order from the object side, a front lens group, a stop, and a rear lens group. The front lens group is formed of, in order from the object side, a first lens element and a second lens element, each of positive meniscus shape with their convex surfaces on the object side, and a third lens element that has a negative meniscus shape with its convex surface on the object side. The rear lens group is formed of, in order from the object side, a fourth lens element which has a negative meniscus shape with its concave surface on the object side, and fifth and sixth lens elements each of which is a positive meniscus lens with its convex surface on the image side. Each lens element surface is spaced from any adjacent lens elements so that no lens element surfaces are joined to form a combined lens. Further, specified conditions are satisfied to ensure that the Gaussian lens for photography has high optical performance, provides a flat image surface over the entire field of view, and may be readily manufactured so as to keep production costs low.

Gaussian lens for photography

There is described a data-imprinting optical system for use with a camera which is composed of a single meniscus lens having a positive refracting power and a brightness aperture, which can be applied to a low-cost unsophisticated camera of manual advance type by satisfying predetermined conditional equations, and which enables miniaturization of and space-saving in a camera. Specifically, the data-imprinting optical system includes a single positive meniscus lens and a brightness aperture disposed on the part of a data display member. The positive meniscus lens is a plastic lens having an aspherical concave surface on the part thereof facing the data display member. An image of display information appearing on the data display member is projected on a film surface.

Data-imprinting optical system for camera

A compact, real-image-type zoom finder having a high zoom ratio and high optical performance is provided. The finder is formed of an objective optical system and an erecting eyepiece. The objective optical system is formed of, in order from the object side, a first lens element having negative refractive power with a concave surface on the object side, a second lens element having positive refractive power, and a third lens element that is a positive meniscus lens with its convex surface on the object side. The erecting eyepiece is formed of an erecting prism having refractive surfaces integrally formed on the input end and output end of the erecting prism. The magnification of the finder is changed by moving the second lens element along the optical axis, and the third lens element is moved along the optical axis in order to adjust for what would otherwise be a shifting in image surface position with the change in magnification. Specified conditions are satisfied in order to provide a compact structure and high image quality.

Real-image-type zoom finder

A pseudo zoom camera, which utilizes a film cartridge provided with an information storing device, comprises a taking lens optical system for projecting an object image onto a portion of photographic film, which portion has been pulled out of the film cartridge. The camera also comprises a finder optical system capable of displaying an image of a field angle, which is different from the field angle of the object image formed by the taking lens optical system, in a predetermined region representing an image-recording range. A writing device writes information representing an image range ratio of the image, which is displayed in the predetermined region by the finder optical system, to the object image, the information being written on the information storing device of the film cartridge.

Photo printing system and camera for the same

Simple power-variable finder

A two-focus switchable lens comprises a taking lens system selectively using a wide-angle-side lens and a telephoto-side lens having respective focal lengths different from each other; and a fixed shutter,, disposed on an image surface side of the taking lens system, for determining an amount of exposure. The wide-angle-side lens comprises two meniscus lenses L,, L,each having a concave surface directed onto the object side; whereas an aperture stop,for defining brightness is disposed between the lens L,and the fixed shutter,, with a single blade configuration, positioned on the image surface side of the lens L,. The telephoto-side lens comprises a single positive meniscus lens L,&prime; having a convex surface directed onto the object side, whereas an aperture stop,&prime; is disposed between the lens L,&prime; and the fixed shutter,, with a single blade configuration, positioned on the image surface side of the lens L,&prime;. Also, a marginal luminous flux restricting mask,is disposed on the image surface side of the fixed shutter

Two-focus switchable lens

A wide-angle zoom lens is disclosed having four lens groups of negative, positive, positive, and positive refractive power, in order from the object side. By satisfying prescribed conditions, the overall length as well as the outer diameter of the wide-angle zoom lens can be kept small, the number of lens elements required can be minimized so as to keep manufacturing costs low, yet a high-quality image is provided over the entire range of zoom. During zooming, the first and fourth lens groups remain in a fixed position while the second and third lens groups are moved along the optical axis. The first lens group G.sub.1 includes at least one negative lens element with a concave surface of strong curvature on the image side. The second lens group G.sub.2 has at least one biconvex lens. The third lens group G.sub.3 may consist of a single positive lens. The following conditions are satisfied:

Wide-angle zoom lens

A wide-angle zoom lens of simple construction, having only four lens elements and three lens groups is disclosed. The refractive power of the lens groups is, in order from the object side, negative, positive and positive. An aperture stop 1 is arranged between the first lens group G.sub.1 and the second lens group G.sub.2. The lens is intended for use in a compact electronic still camera having a small overall length as well as a small lens diameter. When zooming, the position of the second lens group and the third lens group is varied along the optical axis. Predetermined conditions are satisfied in order to obtain a compact zoom lens having high optical performance over the entire range of zoom.

Growing community of inventors

Saitama, Japan

Kazunori Ohno