Fujifilm Corporation

Fuji Photo Optical Co., Ltd.

Fujinon Corporation

Yoshitaka Mori

Shigeru Yamamoto

Shinichi Shimotsu

Minoru Tanaka

Toshiaki Takeda

Takayuki Matsuura

There are provided a variable magnification optical system and a control method thereof which are capable of relatively accurately adjusting a positional relationship between a variable magnification optical device and an imaging surface of an imaging device according to a zoom amount. A zoom lens included in the variable magnification optical device is positioned at a telephoto end and a wide angle end, and shift amounts &#x394;Sand &#x394;S, tilt angles &#x3b8;and &#x3b8;, rotation angles &#x3d5;and &#x3d5;, and focusing adjustment amounts &#x394;and &#x394;of the variable magnification optical device are set by a user and are stored. In a case where a zoom amount of the zoom lens is set to a desired value by the user, a shift amount corresponding to the set zoom amount is calculated by using the stored shift amounts &#x394;Sand &#x394;S. The positional relationship between the variable magnification optical device and the imaging surface of the imaging device is adjusted so as to have the calculated shift amount.

Variable magnification optical system and control method thereof

The purpose of the present invention is to reduce the size of an image pick-up lens unit. A part of a bundle of rays representing subject optical images is deflected vertically downward by a polarization prism, and is further deflected forwards by a total reflection mirror. A bundle of rays totally reflected by the total reflection mirror is split in three directions by a tri-directional splitting prism. The bundle of rays, which is split in three directions, is incident on a first optical-path-length-difference image pick-up element, a second optical-path-length-difference image pick-up element, and a phase-difference image pick-up element included in a phase-difference AF optical system. Auto focus (AF) is performed on the basis of the optical path length difference from signals obtained from the optical-path-length-difference image pick-up elements, and AF is performed on the basis of the phase difference from a signal obtained from the phase-difference image pick-up element. Since the phase-difference AF optical system is disposed so as to be parallel to the axis of the light forming the subject optical images, the size of the image pick-up lens unit can be reduced.

Lens device

Disclosed is a rear-focus-type lens device in which a switch assembly including a plurality of switches can be provided in an attachment frame having, for example, a focus lens accommodated therein and which is capable of ensuring the strength of the attachment frame and the accuracy of the parts. A mounting frame provided on the rear side of a lens barrel body includes: an inner wall that partitions the inside of the mounting frame into a first space which accommodates an internal structure including, for example, a focus lens and a second space which accommodates a switch assembly including a plurality of switches for operating the lens device; and an opening of the second space which is formed in the side surface of the mounting frame and to which the switch assembly is attached. The strength of the mounting frame is ensured by the inner wall.

Disclosed is a lens device including a click mechanism of a ring member that is rotated with respect to a lens barrel body, slides in the optical axis direction, has high slidability during a click operation and high durability, and can prevent one-sided abrasion due to the inclination of the ring member. A click mechanism of a first focus ring includes: elastic members for clicking provided at three equally divided positions on the circumference of a front fixed ring of a lens barrel body; and a contact portion that is formed in a central portion of the inner circumferential surface of the first focus ring and comes into contact with a convex portion of the elastic member for clicking. The elastic member for clicking is made of polyacetal with high slidability. Therefore, it is possible to reduce the abrasion of the elastic member for clicking during a click operation.

A lens barrel comprises: a first focus ring used for either one of instruction types of focus operation of a relative position instruction type focus operation for moving a position of the focus lens for focus control and an absolute position instruction type focus operation for moving it in an absolute positional relation; a second focus ring used for the focus operation of the instruction type different from that of the first focus ring between the relative position and the absolute position instruction type focus operation; a support device which slidably supports the first focus ring; a connecting device which brings the first focus ring and the second focus ring from an unconnected state into a connected state when the first focus ring is slid from a first position to a second position; and a cover member covering the outer circumference portion of the second focus ring.

Lens barrel

The present invention provides a lens barrel having an optical system capable of change of a focal length, comprising: a diaphragm device which controls a light amount of light incident to the optical system and passing to an image forming surface; and an open F value varying device which is provided separately from the diaphragm device, controls a light amount of the light incident to the optical system and passing to the image forming surface and varies an open F value by limiting the light amount so that the open F value becomes a value according to a focal length of the optical system when the light amount which is controllable by the diaphragm device is at the maximum.

An auxiliary lens with which lenses are held within a mount has an afocal magnification of 0.8 and serves as a wide-angle conversion lens when attached to the front face of a taking lens with a small aperture. On the other hand, when attached to the front face of a taking lens with a large aperture, the auxiliary lens serves as a ratio conversion lens for an aspect ratio switchable camera which can switch an aspect ratio of the imaging area from 16:9 to 4:3.

Converter

A small and light TV camera extender switching apparatus which is capable of switching two extenders having different magnifications. A first extender and a second extender are supported by the same support shaft so as to be rotatable independently of each other. The first extender and the second extender are rotated by operating the first operating lever and the second operating lever, respectively, via gear trains, so that either extender is moved from the resting position outside of an imaging optical path to a working position in the imaging optical path. A stopper mechanism which is capable of adjusting a retaining position is disposed on the lens frame or in the case so as to adjust the retaining positions of each extender at the resting position and the working position.

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Saitama, Japan

Yoshitaka Mori