Canon Kabushiki Kaisha

Sony Corporation

Other

Toshihiro Sunaga

Koshi Hatakeyama

Katsumi Kurematsu

Takahiro Sasaki

Takeshi Akiyama

Sawako Chatani

Takayuki Ishii

Keisuke Araki

Masaharu Hosoi

Motoyuki Otake

Yoshiaki Kurioka

Kotaro Yano

Hiroaki Hoshi

Jun Nishikawa

Tsunefumi Tanaka

Makoto Sekita

Kenichi Kimura

Makoto Kanai

Yumiko Ohsaki

Yumiko Kato

Masaki Maruyama

An image pickup lens includes: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; and a fourth lens group having negative refractive power, arranged in order from an object side to an image side, the fourth lens group being configured to travel along an optical axis through focusing operation. In the image pickup lens, following conditional expression (1) is satisfied,4&#x3c;&#x2212;0.35&#x2003;&#x2003;(1)where f is a total focal length of the image pickup lens, and f4 is a focal length of the fourth lens group.

Image pickup lens and image pickup apparatus

A zoom lens includes: first to fourth lens groups having positive, negative, positive, and negative refractive power, respectively. The first to fourth lens groups are arranged in order from the object plane. The fourth lens group is configured of one negative lens or a cemented lens including positive and negative lenses that are arranged in order from object plane and are attached to each other. A magnification-varying operation from wide end to telephoto end causes the first and third lens groups to travel toward the object plane and causes the second and fourth lens groups to travel along an optical axis. A focusing operation causes the fourth lens group to travel along the optical axis. The following conditional expression is satisfied:0.7&#x3c;(44)/(44)&#x3c;5&#x2003;&#x2003;(1)

Zoom lens and image pickup unit

An imaging lens includes: a first lens group; a second lens group having positive refractive power; and a third lens group having negative refractive power, which are arranged in order from an object side, wherein the first lens group includes a former lens group having a negative lens in a most object side, a diaphragm, and a rear lens group, and wherein, when focusing is performed, the second lens group is moved in the optical axis direction.

Imaging lens and imaging apparatus

A zoom lens includes: first, second, third and fourth lens groups having negative power, positive power, negative power and positive power, respectively, and sequentially arranged from an object side toward an image side. When the magnification at a wide angle side is changed to the magnification at a telescopic side, the first lens group is so moved along an optical axis that the distance between the first lens group and the second lens group decreases, and the second third and fourth lens groups are moved from the image side toward the object side, the third lens group is moved along the optical axis for focusing, and the zoom lens satisfies the following conditional expression (1)&#x2212;2.0&#x3c;3/&#x221a;()&#x3c;&#x2212;0.3&#x2003;&#x2003;(1)where f3, fw and ft represent the focal lengths of the third lens group, the entire lens system at the wide angle end, and the entire lens system at the telescopic end, respectively.

Zoom lens and imaging apparatus

Provided is an imaging lens including a fixed first lens group having a positive refractive power and including a plurality of lenses, a second lens group serving as a focus group and including a negative lens, and a third lens group having a positive refractive power that are arranged sequentially from an object side to an image side. A stop is disposed between predetermined lenses of the first lens group, and, on an assumption that a lens group located closer to the object side than the stop of the first lens group is a 1alens group and a lens group located closer to the image side than the stop is a 1blens group, Condition Equation (1) below is satisfied:0.7&#x3c;1&#x3c;2.0,&#x2003;&#x2003;(1)where f is a focal distance of an entire system and f1b is a focal distance of the 1blens group.

Provided is an imaging lens including a fixed first lens group having a negative refractive power, a second lens group having a positive refractive power, a stop, a third lens group including a cemented lens, a fourth lens group including a positive lens, a fifth lens group serving as a focus group and including a negative lens, and a sixth lens group including a positive lens that are arranged sequentially from an object side to an image side.

There is a need for providing a projection optical system that is appropriate for maintaining high resolution with low distortion, miniaturizing a reflector, decreasing the number of reflectors, and decreasing the depth and the bottom (or top) of a display used for a rear projection television, for example. The projection optical system according to the invention enlarges and projects images from a primary image surface existing at a reducing side to a secondary image surface existing at an enlarging side. The projection optical system has a first optical system Land a second optical system L. The first optical system Lforms an intermediate image (position II) of the primary image surface. The second optical system Lhas a concave reflector AMthat forms the secondary image surface resulting from the intermediate image. A light beam travels from the center of the primary image surface and to the center of the secondary image surface and crosses an optical axis. The light beam is reflected on the concave reflector, crosses the optical axis again, and reaches the secondary image surface.

Projection optical system and projection-type image display apparatus

A polarizing beam splitter includes: first and second prisms each having first and second end surfaces serving as an input surface or an output surface of light and an opposed surface as side surfaces of a pillar-like member; and at least two parallel flat layers disposed in parallel between the opposed surfaces of the first and second prisms. Here, one of the least two parallel flat layers is a first parallel flat layer polarization-separating the input beam. When it is assumed that the refractive index of a base material of the first and second prisms is Np, the resultant refractive index of the parallel flat layers other than the other parallel flat layer of the at least two parallel flat layers is Na, and the refractive index of the other parallel flat layer of the at least two parallel flat layers is Nb, (Na&#x2212;Np)&#xd7;(Nb&#x2212;Np)&#x3c;0 is satisfied.

Polarizing beam splitter, projection optical system, projection display

To obtain an original reading imaging optical system, with which a carriage integral type scanning system can be readily realized in an original reading system such as a digital copier for which high-speed performance and high resolution are required, and an image reading apparatus using the same. According to the present invention, by crossing optical paths in a reflection optical system, the more compact imaging optical system capable of coping with decentering error can be attained. Further, by crossing the optical paths on an object side from a diaphragm, the still more compact imaging optical system can be attained. As a result, the original reading imaging optical system of the carriage integral type scanning system and the image reading apparatus using the same can be provided.

Imaging optical system and image reading apparatus using the same

A scan type display optical system is disclosed in which the position and inclination of an image formed by projection light is made variable. The scan type display optical system comprises an optical scanning member for deflecting and scanning light, and a projection optical system which includes a plurality of optical surfaces containing a reflective surface. The projection optical system projects light from the optical scanning member. An incidence range of light from the optical scanning member to a first optical surface on which the light is incident initially out of the plurality of optical surfaces is variable.

Scan type display optical system

A projection optical system is disclosed with which undistorted images can be obtained at any image position within a specification range, and whose projection angle can be changed. The projection optical system includes a plurality of optical elements and a first optical system constituted by at least one of the plurality of optical elements having the ability to form an image with light onto a predetermined surface different from the projection surface. A projection image of the original image can be moved by rotating a first optical element of the plurality of optical elements substantially around a center of an exit pupil position of the first optical system as the rotation center.

Projection optical system

A catoptric projection optical system for projecting a pattern on an object surface onto an image surface includes plural mirrors, wherein a second mirror from the image surface through the optical path receives convergent pencil of rays, and has a paraxial magnification of &#x2212;0.14 or smaller.

Catoptric projection optical system

Provided is a compact optical element that secures an optical path length and improves manufacturing precision economically. The optical element includes a transparent member having a first and second refracting surface, and reflecting surfaces. Light entering the transparent member from the first refracting surface is reflected by the reflecting surfaces to the second refracting surface. An optical path from the first to second refracting surface crosses itself inside the transparent member seen from a direction perpendicular to light entering the first refracting surface and exiting the second refracting surface. The transparent member guides the incident light from the first to the second refracting surface while reflecting the light alternately by at least one first and one second reflecting surface is in a first and second region respectively. The first and second regions and, respectively, are on opposite sides of a plane passing through the transparent member taken as a boundary.

Optical element, optical system, and optical device

A projection optical system includes an optical modulation unit which outputs modulated light for displaying an image, an optical scanning unit on which the modulated light output from the optical modulation unit is incident, the optical scanning unit scanning the light from the optical modulation unit to obtain a two-dimensional image, and a plurality of curved reflecting surfaces on which the light scanned by the optical scanning means is sequentially incident, the plurality of curved reflecting surfaces sequentially reflecting the light scanned by the optical scanning means and projecting the light on a projected surface, wherein when an optical path of a ray connecting a center of a pupil of the projection optical system and a center of a projected image is set as a reference axis, the reference axis is inclined with respect to a normal to the projected surface.

Growing community of inventors

Kanagawa, Japan

Toshihiro Sunaga