Abstract: An optical element includes an incidence surface, one or more reflecting surfaces reflecting light from the incident surface, an emergence surface, and off-axial curved surfaces causing the light to emerge from the emergence surface. At least one of the incidence surface, the emergence surface and the one or more reflecting surfaces is a surface having diffracting action. The surface having the diffracting action is a curved surface.

Abstract: In an optical element for reflecting light from an incidence surface of the optical element by one or more reflecting surfaces comprising off-axial curved surfaces, and causing the light to emerge from an emergence surface, at least one of the incidence surface, the emergence surface and the reflecting surface diffracting the light.

Abstract: The present invention relates to an image displaying apparatus comprising an image displaying device for radiating light to display an image, a first optical system for forming the image on a primary image plane, which has a magnification-changing portion for changing an image magnification of the image and a second optical system for guiding light from the primary image plane to the pupil of an observer in order to enable the observer to observe an enlarged, virtual image of the image formed on the primary image plane.

Abstract: There is disclosed an image taking apparatus comprising a first optical unit for forming an image, a second optical unit positioned on the optical axis of the first optical unit, a third optical unit positioned behind the second optical unit and having plural lens units for re-focusing parts of the image of the first optical unit, converters for converting the plural images, formed by the third optical unit, into electrical signals, and a processor for processing the electrical signals from the converters in order to obtain an image of a high definition.

Abstract: An optical apparatus is provided with a lens unit movable in the direction of the optical axis thereof, a lens barrel, an electromagnetic coil coupled to one of the lens unit and the lens barrel, a driving unit having a magnetic material coupled to the other of the lens unit and the lens barrel, and a guide for slidably guiding the lens unit relative to the lens barrel.

Abstract: This specification discloses a polarization converting apparatus having means emitting non-polarized light, and polarizing means having a light incidence surface and a light emergence surface, the polarizing means receiving the non-polarized light by the light incidence surface and causing polarized light to emerge from the light emergence surface, the size and shape of the light incidence surface being similar to the size and cross-sectional shape of the non-polarized light. The specification also discloses an optical instrument having such apparatus.

Abstract: This specification discloses an optical apparatus provided with a lens unit movable in the direction of the optical axis thereof, a lens barrel, an electromagnetic coil coupled to one of the lens unit and the lens barrel, a driving unit having a magnetic material coupled to the other of the lens unit and the lens barrel, and a guide for slidably guiding the lens unit relative to the lens barrel.

Abstract: An image stabilization apparatus of an inertial pendulum type corrects vibration of an image by a correcting optical device relatively displaceable with respect to a barrel. The apparatus includes a restriction device for generating an operational effect which changes according to a position of the correcting optical device for restricting the relative displacement of the correcting optical device, and a controller for changing the effect of the restriction device in accordance with a focal length or a direction of displacement of the correcting optical device.

Abstract: An active, external distance measurement type apparatus for focus adjustment of a photographic lens comprises a light emitting element arranged outside a light beam passing through the photographic lens, a projection lens for projecting light from the light emitting element to an object field, a collection lens arranged in spaced relation to the projection lens by a base line length, and a photosensitive element to which the irregular reflection of the light rays projected by the projection lens onto an object to be phtotgraphed is directed by the collection lens. An optical unit is arranged to refract a portion of each of a projecting light beam and a receiving light beam in a different direction so that parallax is compensated for.

Abstract: A zoom lens comprising a front lens group including a lens unit for decentering relative to an optical axis to stabilize an image at the focal plane and a rear lens group including lens units movable along the optical axis for zooming on the image side of the front lens group.

Abstract: An image-stabilized optical device comprising, from front to rear, a first lens group of negative power, a second lens group of positive power and a rear lens group of positive power for forming an image, wherein the second lens group rotates around a point which is on the optical axis away from its rear principal point rearward by a distance of about .beta.2.multidot.f1/(1-.beta.2) where .beta.2 is the image magnification of the second lens group and f1 is the focal length of the first lens group, and lies within the rear lens group, whereby the image is stabilized against accidental vibrations.

Abstract: A focus detecting device and a photographic apparatus provided with such a device has an apparatus for setting optic axes thereof with a base length therebetween, and for photoelectrically detecting a focus state thereof, at least one of the optic axes being bent, or reflected, by a fixed reflecting surface, and a focus detection component disposed along the bent optic axis and movable, during a focus detection operation, in a direction intersecting the bent axis.

Abstract: A zoom lens comprising, from front to rear, a first lens unit of negative power and a second lens unit of positive power, both lens being axially moved to effect zooming, in which a diaphragm is arranged between the first and second lens units to remain stationary during zooming.

Abstract: A front conversion lens is disclosed comprising, from front to rear, a first lens unit made of glass material, a second lens unit made of plastic material, and a third lens unit made of glass material.

Abstract: A compact zoom lens comprising, from front to rear, a first lens unit of positive power for focusing, a second lens unit of negative power axially movable in one direction when zooming from one end of a range of image magnification to the other, a third lens unit of positive power axially movable in a path convex toward the rear to maintain the constant position of an image surface which shifts with zooming, and a fourth lens unit of positive power for forming an image which remains stationary during zooming, wherein a fixed diaphragm is arranged in a space between the second and third lens units.

Abstract: To minimize the size of a front conversion lens, an aperture stop is arranged on the object side of a master lens, and the front conversion lens is made releasably attachable.

Abstract: A zoom lens comprising, from front to rear, a first lens unit of negative refractive power and a second lens unit of positive refractive power, in which either by moving the second lens unit forward to vary the magnification from the wide angle side to the telephoto side, a supplementary lens system is attached on the image side of the second lens unit in the middle of the course of varying the magnification or in the zooming position of the telephoto end side, or by moving at least the second lens unit forward, the supplementary lens system is attached, to change the focal length of the entire system.

Abstract: A diaphragm device including a pair of diaphragm blades movable in opposite directions relatively to each other along a moving line passing through an optical axis of an optical system characterized in that each of the diaphragm blades is provided with an opening of a shape consisting of combination of an arc having a center of curvature located on said moving line and at least one arc having a radius smaller than the above-mentioned arc and having a center of curvature located on said moving line or on a line at right angle to said moving line.

Abstract: A zoom lens including a plurality of movable lens units for zooming, a diaphragm and a beam splitter for splitting off part of the light beam toward an optical device, characterized in that this beam splitter is arranged in between the frontmost and rearmost movable zoom units.

Abstract: A zoom lens comprising a first lens unit of positive refractive power for focusing, a second unit of negative refractive power movable for zooming in a mono-direction throughout, a third unit of positive refractive power movable for zooming in the opposite mono-direction to that of movement of the second unit, and a fourth unit of positive refractive power having an image forming function which is held stationary during zooming, with a diaphragm being arranged in between the second and third units to be stationary.