Asahi Kogaku Kogyo Kabushiki Kaisha

Asahi Kogaku Kogyo K.k.

Asahi Kogaku Kabushiki Kaisha

Asahi Kogaku Kogyo Kaisha

Keisuke Haraguchi

Shinsuke Kohmoto

Shigeru Kondoh

Takeo Kobayashi

Norio Numako

Hideki Ohkubo

Saburo Sugawara

Katsuhiko Nomura

Susao Nakamura

Hirofumi Matsuo

Etsuro Nishio

Haruo Ishii

Yukio Takaoka

Toru Kando

Takayuki Ito

Tomoaki Kobayashi

Harumi Aoki

Akihiro Arai

Fumio Urano

Hiroshi Kurei

Yasumasa Tomori

Mituhiko Shimoda

Masaaki Morizumi

Shiyouichi Yamaka

Masahiro Hyakawa

Hideki Oukubo

A zoom lens for a camera having a between-the-lens shutter includes a motor for moving the lens along an optical axis in forward and rearward directions. A switch is operable by an operator to control operation of the motor for moving the lens from an initial position on the axis to a final stationary position that establishes the focal length of the lens. Control apparatus is responsive to the setting of the switch for operating the motor such that movement of the lens from its initial position to its final position always ends after the lens travels to its final position in a predetermined direction.

Zoom lens drive system for lens shutter type of camera

A lens shutter type of camera is disclosed in which a zoom lens is positioned in a lens block (1) which has a sector gear (15) rotatably associated with the lens block and with a rotatable cam ring (14). The cam ring and sector gear are rotatable in a substantially constant axial position. A movable finder optical assembly (8) and a movable strobe assembly (9) are movable in association with movement of the zoom lens. The zoom lens is movable between an extreme telephoto position and an extreme wide angle position, as well as into a fully collapsed lens position beyond the extreme wide angle position and a macro or close-up photographing position beyond the extreme telephoto position. When the camera is in its macro mode, a prism (P1) is inserted into the finder optical assembly to correct for parallax; the strobe assembly is moved to change its illumination angle; and an optical wedge (4e) is pivoted into the path between a light receiver (4) and a light emitter (3e). A single cam plate (53) is provided to move the finder assembly and the strobe assembly. The photographic aperture (22b) can be selectively closed by barrier plates (31a) when the zoom lens is moved into its fully collapsed position. A light intercepting assembly (210) is provided for preventing light from entering the photographic optical assembly via cam grooves (20 and 21). This intercepting assembly includes a flexible code plate (90) which surrounds a peripheral portion of the cam ring (14) and which provides positional information relating to the position of the zoom lens.

Lens shutter camera including zoom lens

A lens shutter type of camera is disclosed in which a zoom lens is positioned in a lens block (1) which has a sector gear (15) rotatably associated with the lens block and with a rotatable cam ring (14). The cam ring and sector gear are rotatable in a substantially constant axial position. A movable finder optical assembly (8) and a movable strobe assembly (9) are movable in association with movement of the zoom lens. The zoom lens is movable between an extreme telephoto position and an extreme wide angle position, as well a into a fully collapsed lens position beyond the extreme wide angle position and a macro or close-up photographing position beyond the extreme telephoto position. When the camera is in its macro mode, a prism (P1) is inserted into the finder optical assembly to correct for parallax; the strobe assembly is moved to change its illumination angle; and an optical wedge (4e) is pivoted into the path between a light receiver (4) and a light emitter (3e). A single cam plate (53) is provided to move the finder assembly and the strobe assembly. The photographic aperture (22b) can be selectively closed by barrier plates (31a) when the zoom lens is moved into its fully collapsed position. A light intercepting assembly (210) is provided for preventing light from entering the photographic optical assembly via cam grooves (20 and 21). This intercepting assembly includes a flexible code plate (90) which surrounds a peripheral portion of the cam ring (14) and which provides positional information relating to the position of the zoom lens.

A lens shutter type of camera is disclosed in which a zoom lens is positioned in a lens block (1) which has a sector gear (15) rotatably associated with the lens block and with a rotatable cam ring (14). The cam ring and sector gear are rotatable in a substantially constant axial position. A movable finder optical assembly (8) and a movable strobe assembly (9) are movable in association with movement of the zoom lens. The zoom lens is movable between an extreme telephoto position and an extreme wide angle position, as well a into a fully collapsed lens position beyond the extreme wide angle position and a macro or closeup photographing position beyond the extreme telephoto position. When the camera is in its macro mode, a prism (P1) is inserted into the finder optical assembly to correct for parallax; the strobe assembly is moved to change its illumination angle; and an optical wedge (4e) is pivoted into the path between a light receiver (4) and a light emitter (3e). A single cam plate (53) is provided to move the finder assembly and the strobe assembly. The photographic aperture (22b) can be selectively closed by barrier plates (31a) when the zoom lens is moved into its fully collapsed position. A light intercepting assembly (210) is provided for preventing light from entering the photographic optical assembly via cam grooves (20 and 21). This intercepting assembly includes a flexible code plate (90) which surrounds a peripheral portion of the cam ring (14) and which provides positional information relating to the position of the zoom lens.

Lens shutter camera including zoom lens drive system

A lens shutter type of camera is disclosed in which a zoom lens is positioned in a lens block (1) which has a sector gear (15) rotatably associated with the lens block and with a rotatable cam ring (14). The cam ring and sector gear are rotatable in a substantially constant axial position. A movable finder optical assembly (8) and a movable strobe assembly (9) are movable in association with movement of the zoom lens. The zoom lens is movable between an extreme telephoto position and an extreme wide angle position, as well a into a fully collapsed lens position beyond the extreme wide angle position and a macro or close-up photographing position beyond the extreme telephoto position. When the camera is in its macro mode, a prism (Pl) is inserted into the finder optical assembly to correct for parallax; the strobe assembly is moved to change its illumination angle; and an optical wedge (4e) is pivoted into the path between a light receiver (4) and a light emitter (3e). A single cam plate (53) is provided to move the finder assembly and the strobe assembly. The photographic aperture (22b) can be selectively closed by barrier plates (31a) when the zoom lens is moved into its fully collapsed position. A light intercepting assembly (210) is provided for preventing light from entering the photographic optical assembly via cam grooves (20 and 21). This intercepting assembly includes a flexible code plate (90) which surrounds a peripheral portion of the cam ring (14) and which provides positional information relating to the position of the zoom lens.

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

Growing community of inventors

Tokyo, Japan

Keisuke Haraguchi