Abstract: An actuator comprises: an electro-mechanical conversion element; a connecting member affixed to one side in an extension/contraction direction of the electro-mechanical conversion element; a rod-like driving frictional member affixed to the connecting member and positioned in parallel to the extension/contraction direction of the electro-mechanical conversion element; and a driven member frictionally engaged with the driving frictional member.

Abstract: A ring-shaped flare stopper is made of a phosphor bronze plate having a thickness of 0.03 mm by sheet metal stamping. An inner periphery for defining a circular opening is formed in the flare stopper. The inner periphery has the form of the side face of a circular truncated cone. The flare stopper is so installed in a lens barrel that the inner periphery is inclined with respect to an optical axis of a taking lens unit. Since incident light is not reflected by the inner periphery of the flare stopper, the occurrence of ghost and flare is prevented. To prevent the deformation and misalignment of the flare stopper, the flare stopper installed in the lens barrel is attached to a spacer.

Abstract: A lens holding barrel is fitted in a fixed barrel in a manner that the lens holding barrel is slidable in optical axis direction. A cam ring is rotatably fitted on outer periphery of the fixed lens. Front regulating members are formed on front end of the fixed barrel, and rear regulating member are formed on rear end of the fixed barrel. Three cutouts are formed on inner surface of the cam ring at even intervals, and cams are formed between these cutouts. Vertical walls are formed at both ends of each cam. The cam ring is fitted onto the fixed barrel after the each front regulating member is faced to the each cutout. After that, the cam ring is positioned between the front regulating member and the rear regulating member by rotation of the cam ring. When the cam ring is rotated in a predetermined range, each cam pushes a cam projection against the biasing of the biasing ring, to move the lens holding barrel in the optical axis direction.

Abstract: A lens holding barrel is fitted in a fixed barrel in a manner that the lens holding barrel is slidable in optical axis direction. A cam ring is rotatably fitted on outer periphery of the fixed lens. Front regulating members are formed on front end of the fixed barrel, and rear regulating member are formed on rear end of the fixed barrel. Three cutouts are formed on inner surface of the cam ring at even intervals, and cams are formed between these cutouts. Vertical walls are formed at both ends of each cam. The cam ring is fitted onto the fixed barrel after the each front regulating member is faced to the each cutout. After that, the cam ring is positioned between the front regulating member and the rear regulating member by rotation of the cam ring. When the cam ring is rotated in a predetermined range, each cam pushes a cam projection against the biasing of the biasing ring, to move the lens holding barrel in the optical axis direction.

Abstract: A ring-shaped flare stopper is made of a phosphor bronze plate having a thickness of 0.03 mm by sheet metal stamping. An inner periphery for defining a circular opening is formed in the flare stopper. The inner periphery has the form of the side face of a circular truncated cone. The flare stopper is so installed in a lens barrel that the inner periphery is inclined with respect to an optical axis of a taking lens unit. Since incident light is not reflected by the inner periphery of the flare stopper, the occurrence of ghost and flare is prevented. To prevent the deformation and misalignment of the flare stopper, the flare stopper installed in the lens barrel is attached to a spacer.

Abstract: A diaphragm switching apparatus according to the present invention comprises a gear adapted to rotate in response to a driving force of a focus motor used for driving a focus lens; a shaft for rotatably supporting the gear; a diaphragm switching means, secured to the shaft 12 and adapted to rotate together with the shaft, for switching a diaphragm upon rotating; an intermediate member engaging the diaphragm switching means so as to rotate together with the shaft and being slidable axially with respect to the shaft; an urging means for urging the gear away from the diaphragm switching means by way of the intermediate member by receiving a reaction force from the diaphragm switching means; and a holding part 12a for receiving the gear urged by the urging means.

Abstract: A diaphragm switching apparatus according to the present invention comprises a gear 11 adapted to rotate in response to a driving force of a focus motor used for driving a focus lens; a shaft 12 for rotatably supporting the gear 11; a diaphragm switching means 13, secured to the shaft 12 and adapted to rotate together with the shaft 12, for switching a diaphragm upon rotating; an intermediate member 14 engaging the diaphragm switching means 13 so as to rotate together with the shaft 12 and being slidable axially with respect to the shaft 12 and being adapted to; an urging means 15 for urging the gear 11 away from the diaphragm switching means 13 by way of the intermediate member 14 by receiving a reaction force from the diaphragm switching means 13; and a holding part 12a for receiving the gear 11 urged by the urging means 15.

Abstract: A zoom lens construction of the type including from the object side a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power. The first and third lens groups being held stationary, the second lens group being movable along the optical axis for zooming operation, and the fourth lens group being movable to maintain a plane of focus in compensation for variations in subject distance and shifts of focal point resulting from zooming operations. The zoom lens comprising a stop provided between the second and third lens groups movably along the optical axis, and arranged to be located closer to the imaging plane at the longest focal length of a zooming range than at the shortest focal length thereof.

Abstract: An initial focusing mechanism for a zoom lens system adapted to achieve the initial focusing by moving a variator lens and a compensator lens along an optical axis with respect to a focusing lens. A cylinder cam is slidably movable within a barrel along the optical axis. The cylinder cam carries the variator lens and the compensator lens and is rotatable with respect to the barrel during zooming so that the variator lens and compensator lens can be moved along the optical axis maintaining a given inter-lens optical relationship. A slide element is provided for moving the cylinder cam along the optical axis and locking the cylinder cam at a selected position relative to the barrel. For initial focusing, the cylinder cam is slidably moved along the optical axis which adjustably moves the variator lens and the compensator lens relative to the focusing lens. Upon completion of this adjustment, the cylinder cam is fixed to the barrel.

Abstract: A zoom lens device is disclosed which is ideal for use in a video camera. In the zoom lens device, a zoom ring is provided directly in the rear end of a cam barrel without using any connecting pins, and the zoom ring is exposed out from a fixed barrel so that it can be operated from externally. For this reason, there is eliminated the need for provision of an escape groove for the connecting pins in the fixed barrel and thus the angles of cam grooves can be increased up to a limit beyond which the cam grooves may interfere with each other. As a result of this, a zoom lens device which is compact and is of a high magnification can be realized.