Asahi Kogaku Kogyo Kabushiki Kaisha

Asahi Kogaku Kogyo K.k.

Asahi Kogaku Kabushiki Kaisha

Yukio Takaoka

Masahiro Kawasaki

Takayuki Ito

Keisuke Haraguchi

Shinsuke Kohmoto

Tomoaki Kobayashi

Yoshio Sawada

Tetsuya Abe

Takeo Kobayashi

Jun Takada

Toshiaki Ueda

Hiroshi Kurei

Katsuhiko Nomura

Susao Nakamura

Norimichi Takahashi

Katsuhiko Nozaki

Kazuki Yazawa

Masaaki Morizumi

Shiyouichi Yamaka

Kazumoto Takakusagi

Tadao Kato

A pseudo telephotographic camera includes a photographing device which photographs pictures in two separate pseudo telephotographic frames which together define a panoramic size picture frame. The panoramic size picture frame is formed by optically intercepting the upper and lower portions of a standard frame on a film. The pseudo telephotographic frames are formed on a left and right half of the panoramic size frame by a first mask and a second mask. Alternatively, the pseudo telephotographic frames are formed with a center mask and by moving the film in a predetermined sequence to expose a left half and a right half of the panoramic size frame.

Pseudo telephotographic camera and camera having pseudo telephotographic

A camera is provided having a finder optical system, a photographing optical system separate from the finder optical system, and a macro photographing mode. The camera includes a movable field frame which is normally located at an inoperative position in which it is retracted from an optical axis of the finder optical system, and which is moved to an operative position in which the movable field frame is in the finder optical axis in association with the transfer into the macro photographing mode. The movable field frame is provided with a field opening corresponding to a photographing range of the photographing optical system.

Zoom lens camera having macro photographing function

A method of controlling the focusing of a zoom lens which has a plurality of lens groups including at least one focusing lens group, wherein an amount of deviation from focus caused by a zooming operation is corrected by movement of the focusing lens group. The method includes setting a reference object distance, at which no deviation from focus occurs during zooming of the zoom lens, at a finite object distance, such that the amount of movement of the focusing lens group necessary to effect focusing is determined based upon a reference position corresponding to a position of the focusing lens group at the reference object distance, in accordance with focal length data and object distance data.

Method of controlling a zoom lens assembly

A method of controlling the focusing of a zoom lens which has a plurality of lens groups including at least one focusing lens group, wherein an amount of deviation from focus caused by a zoom operation is corrected by movement of the focusing lens group. The method includes setting a reference object distance, at which no deviation from focus occurs during zooming of the zoom lens, at a finite object distance, such that the amount of movement of the focusing lens group necessary to effect focusing is determined based upon a reference position corresponding to a position of the focusing lens group at the reference object distance, in accordance with focal length data and object distance data. The zoom lens assembly includes a stationary lens barrel and a rotatable cam ring which is supported on the stationary lens barrel for movement in the direction of the optical axis while being rotated, and which includes at least two cam grooves. The zoom lens includes first and third lens groups which are both movable by one of the two cam groups in a direction of an optical axis. A second lens group movable by a second of the two cam grooves in a direction of the optical axis is also provided, as well as a focusing mechanism for moving the second lens group to a position which is determined by focal length data derived from actual positions of the first, second, and third lens groups and object distance data detected by the object distance measuring device.

Method of controlling the zoom lens assembly

Battery receptacle

In a caseless camera, a cover plate having a contact member at the rear side thereof is slidably mounted at the front side of a camera body between its closing and opening positions. An electric flash mounted inside the camera body traversely movably between its restoring and operating positions is provided with an inclined step at the front side thereof. The contact member of the cover plate contacts and downwardly push the inclined step of the electric flash so as to return the electric flash to its restoring position, when the electric flash is in its operating position, upon the sliding movement of the cover plate from its opening positions to its closing position.

Caseless camera

A camera is equipped with a back cover containing an exposure counter mechanism including a gear member in both frictional and gear toothed engagement with a film feeding sprocket of the camera. To accommodate films of different thickness and lengths, the cover is replacable with another having a different pressure plate, and the counter disc has indicia for counting up to 72 frames.

Exposure counter disc mechanism for cameras

A focusing screen holding device for a single-lens reflex camera including a focusing screen, a focusing screen holding frame including focusing adjusting screws, a focusing screen retaining spring, and a hinge on one leaf of which the focusing screen retaining spring is mounted and which has an outer end with a hook engagable with the camera body. The second leaf of the spring is fixedly secured to the camera body so that the focusing screen holding frame is swingable about the shaft of the hinge. The focusing screen is accessible through the lens mount opening to replace and adjust the position of the focusing screen.

Focusing screen holding device

An aperture auxiliary brake control device in a camera in which a speed slowing device operates in association with the lens stopping-down operation. The operation of the speed slowing device is stopped by interrupting the supply of current to an aperture control magnet to selectively employ a shutter priority automatic exposure in which an aperture value control is obtained, an aperture priority automatic exposure, or a manual exposure. The aperture auxiliary brake control device comprises a brake section for braking a brake disk secured to a part of the speed slowing device by interrupting the supply of current to an auxiliary brake magnet. An auxiliary brake magnet control circuit is employed so that only in the shutter priority automatic exposure mode the brake disk is braked before the operation of said speed slowing device is ended. In the aperture priority automatic exposure or in the manual exposure modes, the supply of current to the auxiliary brake magnet is interrupted after a period of time elapses required to stop down the lens to a minimum aperture value thereof. Hence, following this period an auxiliary brake is not applied.

Camera aperture controlling brake

A self-timer in a camera which has a shutter priority automatic exposure adjustment (EE) mode, a manual exposure adjustment mode or an aperture priority automatic exposure adjustment (ES) mode, or all three exposure adjustment modes. In the (EE) mode, light passing through a lens aperture is received by a light receiving element while the lens aperture is being stopped down. When an aperture value (the quantity of light) suitable for the preset shutter speed and film sensitivity is obtained the supply of current of an aperture control magnet having attracted an aperture locking lever is interrupted to lock the operation of the aperture thereby to determine an aperture value. Simultaneously the locking of a top curtain is released by the lever. The camera has an interlocking timer circuit in which, in modes other than the (EE) mode, the supply of current to the aperture control magnet is interrupted in a period of time such that a period of time required for stopping down the aperture to its minimum aperture value is made slightly longer, thereby to release the top curtain. A switch for changing the time constant of the interlocking timer circuit is provided to increase the operating time of the interlocking timer circuit.

Camera electrical self-timer

An automatic exposure camera of the stop value control type is provided with lens stop braking to improve the accuracy of the lens stopping operation while at the same time maintaining a high operating speed. A brake magnet mechanism is provided for decelerating the lens stopping mechanism in response to a control circuit. In one form, the control circuit operates the brake magnet mechanism to effect deceleration slightly before the quantity of light reaches a suitable exposure value. Thereafter, when a stop value providing a suitable exposure value is obtained, stopping the lens stopping operation can be done with very high accuracy. In another form, the control circuit compares the variation in light due to the change in aperture with a variation rate to control the energization and de-energization of the brake magnet. In this way, the non-linear operation which is particularly evident at minimal aperture values is eliminated.

Lens stop braking in automatic exposure cameras of stop value control

An exposure control operation involving diaphragm adjustment is performed in first and second phases. During the first phase, a drag mechanism controls the rate of change of diaphragm value. During the second phase, a braking mechanism cooperates with the drag mechanism to control the rate of change of diaphragm value.

Diaphragm-type exposure control system having braking arrangement

An auxiliary brake control device for use in an automatic exposure camera of the lens stop value control type permits the lens stop operation to be controlled with high accuracy without substantially increasing the lens stop operation time. The auxiliary brake control device is controlled by comparing the variation rate in the measured light which passes through the lens stop with a preset value. In this way, lenses which have different characteristic variation rates can be freely interchanged.

Growing community of inventors

Tokyo, Japan

Yukio Takaoka