Abstract: To provide an aperture mechanism and an optical apparatus which are reduced in size. The aperture mechanism comprising: a driving member to be driven in accordance with an aperture operation; an aperture member having an aperture to be driven by the driving member; a first engagement section connected to one of the driving member and the aperture member; a second engagement section connected to another one of the driving member and the aperture member and engaged with the first engagement section; and a biasing member connected to at least one of the driving member and the aperture member to provide a bias in a direction in which the first engagement section and the second engagement section are facing to each other.

Abstract: To provide an aperture mechanism and an optical apparatus which are reduced in size. The aperture mechanism comprising: a driving member to be driven in accordance with an aperture operation; an aperture member having an aperture to be driven by the driving member; a first engagement section connected to one of the driving member and the aperture member; a second engagement section connected to another one of the driving member and the aperture member and engaged with the first engagement section; and a biasing member connected to at least one of the driving member and the aperture member to provide a bias in a direction in which the first engagement section and the second engagement section are facing to each other.

Abstract: At a lens group position storage unit, the positions of a focus lens group and a zoom lens group detected at the time of a preset operation are stored. In response to an instruction for a go-home operation, a zoom lens group position comparison unit compares the current zoom lens group position with the position detected at the time of the preset operation. If the zoom lens group position assumed when the instruction for the go-home operation is issued is further toward the telephoto side relative to the zoom lens group position at the time of the preset operation, a defocus prevention unit issues a warning so as to prevent defocusing.

Abstract: At a lens group position storage unit, the positions of a focus lens group and a zoom lens group detected at the time of a preset operation are stored. In response to an instruction for a go-home operation, a zoom lens group position comparison unit compares the current zoom lens group position with the position detected at the time of the preset operation. If the zoom lens group position assumed when the instruction for the go-home operation is issued is further toward the telephoto side relative to the zoom lens group position at the time of the preset operation, a defocus prevention unit issues a warning so as to prevent defocusing.

Abstract: Lens barrel has a changeover member for changing the lens focusing operation between automatic focusing and manual focusing. The lens barrel includes an automatic focusing unit for automatically adjusting a focusing operation of the lens, a changeover unit for selectively choosing either the manual focusing unit or the automatic focusing unit, and a locking mechanism for prohibiting the changeover operation of the changeover unit.

Abstract: A lens barrel and a camera system are capable of precisely calculating a photographic magnification and a field range. The lens barrel having a focusing or zooming movable lens unit is stored with effective focal length data corresponding to a position of the movable lens unit, detects the position of the movable lens unit, outputs the corresponding effective focal length data and calculates the photographic magnification and the field range. An accuracy of a calculated value is thereby enhanced enough not to cause an underexposure on the whole or the underexposure in a peripheral portion as compared with a central portion.

Abstract: A lens barrel has a manual focusing ring which is rotatable about the optical axis so as to attain a manual focusing operation, a focusing rotary cylinder which defines the position, in the optical axis direction, of a focusing optical system, and is rotatable about the optical axis, an auto-focusing power transmission member for directly transmitting the moving force from an auto-focusing power source to the focusing rotary cylinder, a free rotation cylinder which is arranged on the focusing rotary cylinder, and is rotatable about the optical axis, a manual focusing power transmission member for transmitting the moving force from the manual focusing ring, a power relaying member which constitutes a differential mechanism together with the manual focusing power transmission member and the free rotation cylinder, and applies the rotation driving force to the focusing rotary cylinder by receiving the moving force transmitted from the manual focusing power transmission member, and a locking member for locking th

Abstract: A lens barrel having an image blur prevention system incorporated into the lens barrel. The image blur prevention system includes an image blur prevention optical system which is arranged to eliminate the problem of harmful light entering the lens barrel. The lens barrel includes an aperture unit having an aperture stop which is positioned in the path of a main optical system, and a filter optical system which is secured to a filter retainer frame and positioned so that a specified interval is maintained between the filter retainer frame and the aperture stop. The image blur prevention optical system, which is moved in a plane perpendicular to the optical axis of the main optical system to prevent image blur, is located between the aperture stop and the filter optical system. When the image blur prevention optical system is moved to prevent image blur, the aperture stop and the retainer frame block harmful light.

Abstract: A lens barrel having a fixed cylinder for holding a photographic optical system, and a rotary cylinder surrounding the fixed cylinder which is provided with a fitting portion for holding the rotary cylinder rotatively, and also, a diametral portion whose diameter is smaller than this fitting portion. The lens barrel further having a printed-circuit board having electric components assembled thereon. This printed-circuit board is arranged on the aforesaid diametral portion of the fixed cylinder in the space formed between the inner circumference of the rotary cylinder and the diametral portion.

Abstract: An electric connecting apparatus for a camera system in which a photographic lens is mounted to a camera body by angular attachment movement through a specified range, comprises, on each of the lens and the body, a movable contact unit and a relatively fixed contact unit. The contact units of each of the lens and the body extend circumferentially over a total angular range that exceeds the attachment movement angle. The contact units of the lens are disposed to avoid interference with portions of the camera body and the contact units of the camera body are disposed to avoid interference with portions of the lens during mounting of the lens.