Abstract: A lens barrel, an image pickup apparatus, a lens drive method and a method of producing a shape memory alloy used for the drive device are disclosed. A drive device includes: a lens group for guiding light from a subject; a shape memory alloy adopted to be deformed by an electricity supplied to the shape memory alloy, for moving the lens group in a direction of an optical axis; and electricity-supply controlling means for controlling an amount of the electricity supplied to the shape memory alloy; and a detecting means for detecting whether a movement of the lens group starts or not. In the drive device, a movement amount of the lens group in the direction of the optical axis is controlled based on the amount of electricity supplied when the detecting means detects the movement of the lens group.

Abstract: A lens barrel, an image pickup apparatus, a lens drive method and a method of producing a shape memory alloy used for the drive device are disclosed. A drive device includes: a lens group for guiding light from a subject; a shape memory alloy adopted to be deformed by an electricity supplied to the shape memory alloy, for moving the lens group in a direction of an optical axis; and electricity-supply controlling means for controlling an amount of the electricity supplied to the shape memory alloy; and a detecting means for detecting whether a movement of the lens group starts or not. In the drive device, a movement amount of the lens group in the direction of the optical axis is controlled based on the amount of electricity supplied when the detecting means detects the movement of the lens group.

Abstract: A lens barrel, an image pickup apparatus, a lens drive method and a method of producing a shape memory alloy used for the drive device are disclosed. A drive device includes: a lens group for guiding light from a subject; a shape memory alloy adopted to be deformed by an electricity supplied to the shape memory alloy, for moving the lens group in a direction of an optical axis; and electricity-supply controlling means for controlling an amount of the electricity supplied to the shape memory alloy; and a detecting means for detecting whether a movement of the lens group starts or not. In the drive device, a movement amount of the lens group in the direction of the optical axis is controlled based on the amount of electricity supplied when the detecting means detects the movement of the lens group.

Abstract: A lens barrel includes a lens group that conducts light from a subject, a lens shell that holds the lens group; a string-formed shape memory alloy element that moves the lens shell in a direction of an optical axis, and a pair of guide shafts formed approximately in parallel to the optical axis of the lens group, wherein the lens shell is integrally formed with a cylindrical portion through which one of the guide shafts penetrates, the string-formed shape memory alloy element contacts with a portion of the lens shell at an approximately central portion of the alloy element, and both ends of the alloy element are fixed at respective positions with a line connecting the optical axis of the lens group and a center of the cylindrical portion between the positions.

Abstract: An image taking apparatus comprising a frame, an image taking lens that includes at least one movable lens that can be moved in a direction of the optical axis of the image taking lens with respect to said frame, a lens frame that supports the movable lens, an actuator for moving the movable lens; and a movable frame that is coupled to a movable element of said actuator, wherein the lens frame and the movable frame are formed integrally.

Abstract: A lens barrel includes a lens group that conducts light from a subject, a lens shell that holds the lens group; a string-formed shape memory alloy element that moves the lens shell in a direction of an optical axis, and a pair of guide shafts formed approximately in parallel to the optical axis of the lens group, wherein the lens shell is integrally formed with a cylindrical portion through which one of the guide shafts penetrates, the string-formed shape memory alloy element contacts with a portion of the lens shell at an approximately central portion of the alloy element, and both ends of the alloy element are fixed at respective positions with a line connecting the optical axis of the lens group and a center of the cylindrical portion between the positions.

Abstract: The present invention concerns a camera incorporating a real-image finder, having a structure more compact than ever. The camera includes an objective optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system. In the camera, a rear end of the reflecting surface is located at a backward position with respect to a film conveyance surface and outside the film conveyance surface, and, a front end of the reflecting surface is located at a forward position with respect to the film conveyance surface and inside the film conveyance surface.

Abstract: The present invention concerns a camera incorporating a real-image finder, having a structure more compact than ever. The camera includes an optical system; an erect-image optical system, having a reflecting surface, to receive a light bundle passed through the objective optical system; and an ocular optical system to receive the light bundle reflected from the reflecting surface of the erect-image optical system. In the camera, a rear end of the reflecting surface is located at a backward position with respect to a film conveyance surface and outside the film conveyance surface, and, a front end of the reflecting surface is located at a forward position with respect to the film conveyance surface and inside the film conveyance surface.