Pentax Corporation

Hoya Corporation

Asahi Kogaku Kogyo Kabushiki Kaisha

Asahi Kogaku Kabushiki Kaisha

Kazunori Ishizuka

Hiroshi Nomura

Takamitsu Sasaki

Maiko Takashima

Toshiharu Suzuki

Kazuyoshi Azegami

Nobuaki Aoki

Nobuyuki Nagai

Shinsuke Shoji

Shinya Suzuka

Yoshihiro Yamazaki

Takuji Hamasaki

Makoto Iikawa

Ken Endo

Yuji Kogure

Hiroaki Suzuki

Kunihiko Shimizu

Kazuhiro Hattori

Makio Oishi

Koto Miya

A cam mechanism of a lens barrel includes a cam ring; and a movable frame which moves along an optical axis when the cam ring is rotated, without rotating relative to the cam ring, by engagement of a cam groove provided on the cam ring with a corresponding cam follower provided on the movable frame. The cam groove is formed as a bottomed cam groove including two inclined side surfaces and a bottom surface which connects the two inclined side surfaces. The cam ring includes a single-sided cam section on an end surface of the cam ring, wherein continuity of the reference cam diagram is maintained along the single-sided cam section, and at least a part of one of the two inclined side surfaces which is positioned closer to a nearby end of the cam ring is absent at the single-sided cam section.

Cam mechanism of a telescoping lens barrel

A light shielding structure of an optical device includes outer and inner annular members which move relative to each other in an axial direction, small and large diameter outer peripheral portions formed on the inner annular member, and a light shielding ring positioned inside the outer annular member and supported thereby. The light shielding ring does not contact the small-diameter outer peripheral portion of the inner annular member. The light shielding ring and the large-diameter outer peripheral portion of the inner annular member coincide with each other in the axial direction in an operating state of the optical device whereby a clearance between the outer annular member and the inner annular member is made light-tight. The light shielding ring and the small-diameter outer peripheral portion of the inner annular member coincide with each other in the axial direction in a non-operating state of the optical device.

Light shielding structure of an optical device

An imaging device includes an axial-direction moving member which moves between an operating position and a retracted position in an optical axis direction, an in-plane moving optical element movable in a plane orthogonal to the optical axis, a controller which moves the in-plane moving optical element in the orthogonal plane to a reference position when the image device changes from the operating state to the retracted state, and a mechanical guide device, provided between the axial-direction moving member and the in-plane moving optical element. In a state where the in-plane moving optical element is deviated from the reference position, the mechanical guide device guides the in-plane moving optical element to the reference position by using a moving force of the axial-direction moving member when the axial-direction moving member moves from the operating position to the retracted position.

Imaging device

A light shielding structure of an optical device, includes a plurality of optical elements arranged at different positions in an optical axis direction. The light shielding structure includes at least one annular light shielding member positioned between two of the optical elements to shield harmful light, and a plurality of springs held between the two optical elements to be resiliently deformable in the optical axis direction. The springs include at least two springs, one of which is held between one of the two optical elements and the annular light shielding member while the other of the two springs is held between the other of the two optical elements and the annular light shielding member. The annular light shielding member is supported between the two optical elements in a balanced state between the spring forces of the plurality of springs.

A lens barrel includes a linear guide member, a linearly advancing/retracting member guided by the linear guide member along an optical axis of an imaging optical system to be movable between operating and retracted positions, and a displaceable element supported by the linearly advancing/retracting member to be movable between an on-axis position in which the displaceable element is positioned on the optical axis and an off-axis displaced position in which the displaceable element is displaced from the optical axis. The linear guide member includes a linear guide projection which extends in a direction parallel to the optical axis to be engaged with the linearly advancing/retracting member. The linear guide projection includes an accommodation through-cutout formed through the linear guide projection in a radial direction, at least part of the displaceable element entering the accommodation through-cutout when the linearly advancing/retracting member is in the retracted position.

Retracting mechanism of a lens barrel

An imaging device includes a rectangular image sensor, and an imaging optical system which includes an on-axis lens element and a radially-retractable lens element. The radially-retractable lens element is supported by a free end of a swingable arm pivoted about an axis eccentric from the imaging optical axis. The on-axis lens element is non-circular, defined by a removed portion from a reference circle thereof along a long side of the image sensor. When in the off-axis displaced position, the radially-retractable lens element utilizes the removed portion of the on-axis lens element and the radially-retractable lens element is offset from a plane through the imaging optical axis and parallel to the short sides of the rectangular imaging surface. The swing axis is on the on-axis lens element side, in the long side direction, closer to the optical axis of the radially-retractable lens element in the off-axis displaced position.

A cam mechanism includes a cam ring having front and rear cam grooves which have a common reference cam diagram and are formed so that a front part of the front cam groove and a rear part of the rear cam groove are omitted from the reference cam diagram. A normal-width section and a wide-width section are provided in each of the front and rear cam grooves. In a zoom range, an associated cam follower of a driven member is engaged in the normal-width section of one of the front and rear cam grooves, and another associated cam follower of the driven member is positioned out of the other of the front and rear cam grooves. In a transition state between the zoom range and an accommodated position, both of the associated cam followers are positioned out of the normal-width sections of the respective front and rear cam grooves.

Cam mechanism of a retractable zoom lens

A retractable photographic lens including a photographing optical system includes a plurality of optical elements including at least two radially-retractable optical elements; wherein the plurality of optical elements are aligned with an optical axis in an operating state of the retractable photographic lens. When the retractable photographic lens moves from the operating state to a fully retracted state, the two radially-retractable optical elements of the plurality of optical elements are radially retracted to respective radially retracted positions thereof away from the optical axis in different radial directions and moved rearward in the optical axis direction to be positioned adjacent to each other in a plane orthogonal to the optical axis.

Retractable photographic lens

A lens barrel movable between a first state, in which optical elements of a photographing optical system are all aligned on an optical axis, and a second state in which at least one of the optical elements is retracted to a radially-retracted position and moved rearward, the lens barrel includes a support ring; a radially-retractable optical element holding frame which supports the radially-retractable optical element, and is supported by the support ring to be movable between a first position corresponding to the first state and a second position corresponding to the second state; and an optical-axis-direction-movement limit device which limits movement of the radially-retractable optical element holding frame in the optical axis direction relative to the support ring when the radially-retractable optical element holding frame is at the first position.

Lens barrel

A retractable lens system includes a linearly movable ring; a radially-retractable optical element supported by the linearly movable ring; an exposure control unit supported by the linearly movable ring and adjacent to the radially-retractable optical element; an exposure control unit recess formed on the exposure control unit to face the radially-retractable optical element when the radially-retractable optical element is in the radially-retracted position; a retracting device which retracts the radially-retractable optical element to the radially-retracted position and brings at least a part of a frame of the radially-retractable optical element to enter the exposure control unit recess when the linearly movable ring retracts from a ready-to-photograph position to a retracted position.

Retractable lens system

A retractable lens system including a radially-retractable optical element movable to a position outside of a common optical axis; a linearly movable frame which supports the radially-retractable optical element; a rotatable member for moving optical element support frames including the linearly movable frame which support the plurality of optical elements, respectively, between a ready-to-photograph position and a retracted position on the common optical axis; a retracting member which retracts the radially-retractable optical element; and an accommodating portion formed on the rotatable member. At least a portion of the radially-retractable optical element enters into the accommodating portion of the rotatable member when the radially-retractable optical element is moved to the radially-retracted position.

A cam mechanism of a zoom lens which includes a front optical element and a rear optical element positioned behind the front optical element in an optical axis direction, the front optical element and the rear optical element being guided linearly in the optical axis direction, the cam mechanism including a cam ring having a first cam groove, for moving the front optical element in the optical axis direction, and a second cam groove, for moving the rear optical element in the optical axis direction, both the first cam groove and the second cam groove being formed on one of an inner peripheral surface and an outer peripheral surface of the cam ring. The first cam groove is positioned behind the second cam groove in the optical axis direction.

Cam mechanism of a zoom lens

A lens system having at least one front movable lens group and a rear movable lens group which are movable in an optical axis direction. The lens system includes a position detector for determining whether the rear movable lens group is positioned in a predetermined normal moving range thereof; and a lens control device which stops the front movable lens group and moves the rear movable lens group rearward into the predetermined normal moving range if the rear movable lens group is in an abnormal moving range thereof in front of the normal moving range during a forward movement of the front movable lens group from a predetermined initial position thereof.

Movable lens control device

A lens barrel includes a helicoid ring provided with a helicoid; a retractable rotational ring which is guided by the helicoid to move along an optical axis while rotating, wherein the retractable rotational ring includes a pair of split retractable rotational rings which are supported so as to integrally rotate and to be relatively movable in the optical axis direction with respect to each other; first and second slide-engaging portions provided on one and the other of the pair of split retractable rotational rings, wherein the first and second slide-engaging portions are slidably engaged with the helicoid; and a biasing device which biases the pair of split retractable rotational rings in opposite directions in the optical axis direction so that the first and second slide-engaging portions are pressed in opposite directions against an opposing pair of first and second guide surfaces, respectively, of the helicoid of the helicoid ring.

A cam mechanism of a zoom lens, includes a cam ring including cam grooves having different reference cam diagrams on at least one of inner and outer peripheral surfaces of the cam ring; and movable frames which include cam followers respectively engaged in the cam grooves, the movable frames being guided linearly in an optical axis direction. Each of the cam grooves includes a zooming section for moving an associated one of the movable frames between a wide-angle extremity position and a telephoto extremity position in the optical axis direction in accordance with rotation of the cam ring, and a zooming-range-extremity stop section, communicatively connected to one end of the zooming section, for preventing the associated one of the movable frames from moving in the optical axis direction from one of the wide-angle extremity position and the telephoto extremity position even when the cam ring rotates.

Growing community of inventors

Kanagawa, Japan

Kazunori Ishizuka