Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An assembly-stage focus adjustment mechanism of a zoom lens barrel including a plurality of lens groups which are moved while distances therebetween are changed to perform a zooming operation, the assembly-stage focus adjustment mechanism including two lens fixing frames to which two of the plurality of lens groups are fixed, respectively; two moving frames which linearly move in an optical axis direction during the zooming operation, the two moving frames being respectively screw-engaged with the two lens fixing frames; and a rotational-direction integrating device which makes the two lens fixing frames rotate as one integral body in a direction of rotation relative to the two moving frames when an assembly-stage focus adjustment operation is performed.

Abstract: A retractable lens system includes optical elements of a photographing optical system, and are positioned on a common optical axis when in a ready-to-photograph state. When the retractable lens system changes from the ready-to-photograph state to a retracted state, a removable optical element of the optical elements is moved to a removed position, and the removable optical element and an element of the remaining optical elements are moved rearward. The element of the remaining elements includes a linearly movable element which moves in the common optical axis direction without changing a distance between the linearly movable element and the removable optical element in the ready-to-photograph state. A part of the removable optical element and a part of the linearly movable element are positioned on a common plane perpendicular to the common optical axis when the retractable lens system changes from the ready-to-photograph state to the retracted state.

Abstract: 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.

Abstract: A heating treatment method includes the steps of: preparing an array of heating chambers, the heating chambers being respectively provided with heaters and connected in series; transporting an object to be heated from an upstream side toward a downstream side of the array to allow the object to pass through the heating chambers; supplying and discharging a warm air flow to and from each heating chamber, and controlling an amount of each supplied warm air flow and an amount of each discharged warm air flow to generate an air flow traveling along a direction in which the object is raised in temperature.

Abstract: 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.

Abstract: 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.

Abstract: A movable lens control device for controlling movements of movable lens groups including a first movable lens group and a second movable lens group, the movable lens control device including a lens driving device for moving the first and second movable lens groups in the optical axis direction; a position detector for detecting a position of the second movable lens group and determining whether the second movable lens group is in a predetermined normal moving range thereof; and a controller which controls operations of the lens driving device to stop the first movable lens group and to move the second movable lens group to a position within the normal moving range upon the position detector determining that the second movable lens group is positioned outside of the normal moving range during a movement of the first movable lens group from a predetermined initial position thereof.

Abstract: 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.

Abstract: A drive mechanism of a zoom lens includes three movable members which support optical elements, including a front movable member, an intermediate movable member and a rear movable member; a common driving member including a driving device for moving the three movable members independently; and a biasing member including first and second spring members which bias the three movable members to remove backlash. One of the front movable member and the rear movable member serves as a common-engaging spring support member to which one end of each of the first and second spring members are connected, and the other of the front movable member and the rear movable member, and the intermediate movable member serve as two single-engaging spring support members to which the other ends of the first spring member and the second spring member are connected, respectively.

Abstract: 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.

Abstract: 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.

Abstract: A drive mechanism of a zoom lens includes three movable members which support optical elements, including a front movable member, an intermediate movable member and a rear movable member; a common driving member including a driving device for moving the three movable members independently; and a biasing member including first and second spring members which bias the three movable members to remove backlash. One of the front movable member and the rear movable member serves as a common-engaging spring support member to which one end of each of the first and second spring members are connected, and the other of the front movable member and the rear movable member, and the intermediate movable member serve as two single-engaging spring support members to which the other ends of the first spring member and the second spring member are connected, respectively.

Abstract: 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.