Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Konica Minolta Photo Imaging, Inc.

Sony Corporation

Tetsuya Arimoto

Takashi Okada

Tetsuo Kohno

Hiroshi Ootsuka

Kenji Ishibashi

Kazuhiko Ishimaru

Masayuki Ueyama

Kenji Konno

Minoru Kuwana

Mamoru Terada

Yasuaki Serita

Hisashi Tokumaru

Yoshihito Souma

Makoto Jin

Hiroshi Ueda

Yasushi Yamamoto

Yoshihiro Hara

Soh Ohzawa

Hiroyuki Matsumoto

Tougo Teramoto

Akiyoshi Nakamura

A zoom lens includes, in an order from an object side, 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 positive refractive power, and in which, during power variation from a wide-angle end to a telephoto end, a distance between the first lens group and the second lens group increases, a distance between the second lens group and the third lens group decreases, and a distance between the third lens group and the fourth lens group decreases, and the zoom lens includes at least one cemented-triplet lens block having negative refractive power, in the fourth lens group.

Zoom lens and image capture apparatus

A zoom optical system according to the present invention is provided with, in order from an object side thereof: a first lens group having a negative refractive power; a second lens group having a positive refractive power; a third lens group having a negative refractive power; and a fourth lens group having a positive refractive power. The zoom optical system moves at least the second lens group and the third lens group for zooming operation from a wide-angle end to a telephoto end. The zoom optical system moves the third lens group for a focusing operation. The first lens group is provided with, in order from the object side of the zoom optical system, a meniscus lens having a negative refractive power whose concave surface faces an image side of the zoom optical system, a reflective optical element, and at least one lens.

Zoom optical system and image pickup apparatus

A variable magnification optical system for forming an optical image of an object on the light-receiving surface of an image sensor with variable magnification includes: from an object side, a first lens unit having a positive optical power, a second lens unit having a negative optical power, a third lens unit having a positive optical power, a fourth lens unit having a positive optical power, and a fifth lens unit. In magnification variation from the wide-angle end to the telephoto end, the first lens unit, the third lens unit, and the fifth lens unit are kept in fixed positions whereas the second lens unit and the fourth lens unit move. The third lens unit includes, from the object side, a positive lens element having a biconvex form, and a negative lens element having a form concave to an image side. The negative lens element has an aspherical surface.

Variable magnification optical system

A zoom lens system has, from the object side, a first lens unit having a optical power, a second lens unit having a negative optical power a third lens unit having a positive optical power, and a succeeding lens unit. The first and the third lens units monotonically move toward the object side during zooming from the shortest focal length condition to the longest focal length condition. A number of predetermined conditions are disclosed which can be satisfied to ensure a high quality, compact zoom lens for a digital camera.

Zoom lens system

A zoom lens system has four or five lens units with the optical powers being +/-/+/- or +/-/+/+/-, respectively, from the object side. The image side lens unit has a negative optical power and is movable, along with at least one other lens unit, in a zooming operation. The zoom lens system satisfies the following conditions: 0.6&lt;LBw/fw&lt;1.7 and 0.6&lt;.vertline.fN/fw.vertline.&lt;1.7, where LBw represents a back focus length at the shortest focal length condition; fw represents a focal length of the zoom lens system at the shortest focal length condition; and fN represents a focal length of the image side lens unit. The lens system can be employed with a solid state imaging device, and an optical low-pass filter and an infrared blocking filter can be positioned between the lens system and the imaging unit.

A zoom lens system has at least three lens units of, from the most object side, a first lens unit having a negative optical power, a second lens unit having a positive optical power and a third lens unit, wherein the distances between the lens units are varied by moving all of the lens units during zooming. The zoom lens system satisfies the predetermined mathematical condition.

A lens testing apparatus detects and evaluates inclination of the image plane as caused by decentering of an optical system. The apparatus has an image provider, a plurality of focusing position detectors, and a calculator. The image provider provides an image to a lens system to be tested for decentering. The detectors detect a focusing position on which light rays exiting from the lens system focus. The calculator calculates inclination of the image plane based on the focusing position detected by the detectors.

Lens testing apparatus and a lens adjusting apparatus

The present invention relates to a zoom lens system used for photo-taking in a 35 mm single lens reflex camera. The zoom lens system consists of, from the object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power. Zooming from a wide-angle side to a telephoto side takes place by moving all of the first lens unit through the fourth lens unit to the object side. Focusing on an object at a short distance is performed by moving the second lens unit to the object side.

Inner focusing zoom lens system

A camera system comprises an operation member provided in an interchangeable lens adapted to be manually operated; a signal sending circuit for sending a signal in response to the manual operation of the operation member; and a controller provided in a camera body which is adapted to switch between an operative state where a predetermined operation is executed and a halt state where the controller is halted after completion of the predetermined operation. The controller switches from the halt state to the operative state in response to the signal from the signal sending circuit to execute the predetermined operation. According to the camera system, since the system controller in the camera body is actuated in response to the operation of the member on the lens side, a camera which can substantially instantaneously respond to a request on the lens side can be realized.

Camera system with zoom lens having presettable focal lengths

A camera system comprises an operation member provided in an interchangeable lens adapted to be manually operated; signal sending circuit for sending a signal in response to the manual operation of the operation member; and a controller provided in a camera body which is adapted to switch between an operative state where a predetermined operation is executed and a halt state where the controller is halted after completion of the predetermined operation. The controller switches from the halt state to the operative state in response to the signal from the signal sending circuit to execute the predetermined operation. According to the camera system, since the system controller in the camera body is actuated in response to the operation of the operation member on the lens side, a camera which can substantially instantaneously respond to a request on the lens side can be realized.

Camera system which compensates for defocusing during operation

A compact zoom lens system comprises from the object side: a first lens component of a positive refractive power; a second lens component of a negative refractive power with a variable air space between the first and second lens components; and a third lens component of a positive refractive power with a variable air space between the second and third lens components. A plurality of aspherical surfaces are employed for the realization of a compact and low-cost zoom lens system. Furthermore, a focusing operation is carried out by both of the first and second lens components or third lens component.

Compact zoom lens system

A camera system which comprises a photo-taking lens assembly of varifocal type including a zooming lens and a focusing lens; a manipulatable member; a zooming drive device for driving the zooming lens during a manipulation of the manipulatable member; a focusing device for driving the focusing lens; a focal length detector for sequentially detecting a current focal length of the photo-taking lens assembly; a zooming amount calculator operable to repeatedly add or subtract a predetermined amount to or from the current focal length during the manipulation of the manipulatable member thereby to sequentially update a target focal length used as a reference for the drive of the zooming lens; a first control adapted to receive the target focal length updated by the zooming amount calculator for calculating the amount of deviation in focus which would occur before the target focal length is attained and also for controlling the focusing device so as to eliminate the amount of deviation in focus which has been calculated; and a second control for controlling the zooming drive device, when the manipulation of the manipulatable member is released, so as to drive the zooming lens to a position where the target focal length calculated by the zooming amount calculator is attained.

Photographic camera system

A zoom lens system comprises from the object side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a third lens unit of positive refractive power, a fourth lens unit of positive refractive power, and a fifth lens unit of negative refractive power. The first, third and fourth lens units move towards the object side in a zooming operation from the shortest focal length condition to the longest focal length condition. Further, the zoom lens system fulfills the following conditions:

Compact high ratio zoom lens system

A compact telephoto lens system with a large aperture whose aberrations are corrected well at any focusing position. This telephoto lens system consists of three lens units, namely a positive, a negative and a positive lens unit and only the negative lens unit moves for focusing.

Telephoto lens system

An improvement of an inverted telephoto type wide angle lens system having, from the object to the image side a front lens group of a negative refractive power which is left stationary upon focusing, and a rear lens group of a positive refractive power which is shiftable for the purpose of focusing is disclosed. The improvement is characterized in that the lens system fulfills the following condition:

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Sakai, Japan

Tetsuya Arimoto