Canon Kabushiki Kaisha

Atsushi Someya

Kazuo Minoura

Kazuhiko Matsuoka

Masayuki Usui

Takeshi Baba

Yukuo Nishimura

Shigeyuki Suda

Yuko Suga

Masayuki Suzuki

Keiichi Sakaguchi

Yuko Miyajima

Takesi Baba

Kazuyo Matsumoto

An optical element whose focal length is variable comprises a medium whose refractive index is variable by temperature, a heating device for imparting heat to the medium to cause an index gradient resulting from a temperature distribution to be created in the medium, and a device for controlling the amount of heat imparted to the medium by the heating device to vary the shape of the index gradient formed in the medium.

Varifocal optical element

A variable aberration imaging optical system comprises an imaging optical system and an optical device disposed in the optical system and capable of controlling the imaging characteristic of the imaging optical system. The optical device has a medium for forming an index gradient therein by heat, and a device for imparting heat to a desired position on the medium.

Variable aberration imaging optical system

This specification discloses a light modulating device comprising a liquid medium whose physical properties are variable by heat, and a heat-generating element for heating the liquid medium to such a degree that boiling does not occur to the liquid medium. The specification also discloses a light modulation apparatus comprising a liquid medium whose physical properties are variable by heat, a heat-generating element for heating the liquid medium to such a degree that boiling does not occur to the liquid medium, and a optical system for taking out one of a light flux modulated by the variation in physical properties of the liquid medium and a light flux not modulated by said variation from a state in which the light fluxes are mixedly present.

Light modulating device

A functional optical element comprises a first optical member, a second optical member provided in contact with said first optical member, the interface between said first optical member and said second optical member being non-flat planar, a means for changing the refractive index of said second optical member, said means for changing refractive index being capable of creating selectively a first state in which said first optical member and said second optical member have an equal refractive index and a second state in which said first optical member and said second optical member have different refractive indices by changing the refractive index of said second optical member.

Functional optical element having a non-flat planar interface with

An optical element having the function of changing the cross-sectional intensity distribution of an incident light beam is comprised of a plurality of prisms. The optical element spatially combines a light beam having been amplitude-divided by an amplitude-dividing mirror provided on the joined surface of the prisms and a light beam having been totally reflected by a total-reflection mirror provided on the outermost one of the prisms to thereby change the cross-sectional intensity distribution of the light beam entering the optical element.

Optical element having the function of changing the cross-sectional

A zoom lens includes a zoom portion for forming a virtual image of an object lying between infinity to a very short distance always at a predetermined position and for varying the imaging magnification of the virtual image, and a relay portion including an erecting one-to-one magnification compound-eye optical system disposed between the zoom portion and an image pick-up surface for forming the virtual image of the object on the image pick-up surface.

Zoom lens

In the disclosed zoom lens of the mechanical compensation type, a first movable lens group, a second movable lens group, a third movable lens group and a fixed lens group are located in sequence from the object end. The first, second and third lens groups are simultaneously moved along the optical axis independently of each so as to change the focal length. The first movable lens group is placed closer to the image at the end of the wide angle position rather than at the end of the telephoto position, while during zooming, the axial movement of the first movable lens from the extreme wide angle position to the extreme telephoto position is smaller than that of the third movable lens group. On the other hand, during focusing, the second and the third lens groups are fixed, while the first movable lens group is moved.

Zoom lens having three movable lens groups

In the disclosed zoom lens a front lens group serves for focusing, a variator group and a compensator group for zooming and a fixed lens group for forming an image. In the basic focal length range the front lens group is fixed while the variator group and the front lens group are movable. In order to increase or decrease the focal length beyond the basic focal length range, the front lens group, the variator group and the compensator group are moved simultaneously. From the wide angle limit or from the telephoto limit of the basic focal length range through the extended range at both ends the front lens group and the variator group are moved simultaneously.

Zoom lens with extended variable focal length range

A zoom optical system is composed of a positive focusing lens group, a negative variating lens group, a negative compensating lens group and a positive rear fixed lens group. A rotating grooved cam moves the variating lens group and the compensating lens group in a given relation to each other along the optical axis in the normal focusing range. The focusing lens group is moved along the optical axis normal range for focusing. The variating lens group is kept stationary on the optical axis while the compensating lens group is moved along the optical axis during close-range focusing.

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Machida, Japan

Atsushi Someya