A mirror drive device that hardly causes a delay of drive of a second mirror with respect to control for a first mirror and enables stable drive. A first holding member holds a first mirror. A supporting member rotatably supports the first holding member. A second holding member holds a second mirror and is rotatably supported by the first holding member. A drive member is rotatably supported by the supporting member and is rotatably connected with the second holding member. Rotation of one of the first holding member and the second holding member interlocks with rotation of the other through rotation of the drive member.

A mirror drive device that hardly causes a delay of drive of a second mirror with respect to control for a first mirror and enables stable drive. A first holding member holds a first mirror. A supporting member rotatably supports the first holding member. A second holding member holds a second mirror and is rotatably supported by the first holding member. A drive member is rotatably supported by the supporting member and is rotatably connected with the second holding member. Rotation of one of the first holding member and the second holding member interlocks with rotation of the other through rotation of the drive member.

A finder optical system is achieved in which object images can be more easily observed. A finder optical system includes an image-erecting member, which erects an object image formed by an objective optical system, provided on an optical path from the object side toward an eyepiece side, wherein the image-erecting member is formed as a penta roof prism provided with a first reflection surface and a second reflection surface, which define a roof reflection surface that reflects an incident light bundle emanated from the object, and the first reflection surface and the second reflection surface are configured as total-reflection surfaces that totally reflect the light bundle including the object image.

A finder optical system is achieved in which object images can be more easily observed. A finder optical system includes an image-erecting member, which erects an object image formed by an objective optical system, provided on an optical path from the object side toward an eyepiece side, wherein the image-erecting member is formed as a penta roof prism provided with a first reflection surface and a second reflection surface, which define a roof reflection surface that reflects an incident light bundle emanated from the object, and the first reflection surface and the second reflection surface are configured as total-reflection surfaces that totally reflect the light bundle including the object image.

A lens barrel of the invention includes: an imaging optical system including a focus adjustment lens; a driver that drives the focus adjustment lens in a direction of an optical axis; a transceiver that transmits and receives a signal to and from a camera body; and a controller that controls the transceiver to repeatedly transmit a first image plane transfer coefficient which is determined in correspondence with a position of the focus adjustment lens included in the imaging optical system and a second image plane transfer coefficient which does not depend on the position of the focus adjustment lens to the camera body at a predetermined interval, and, when the controller repeatedly transmits the second image plane transfer coefficient to the camera body, the controller varies the second image plane transfer coefficient over time.

A driving apparatus includes a driving source supplied with a power and configured to generate a driving force, a first cam member configured to rotate in a first rotational direction in accordance with the driving force from the driving source, a driving member configured to drive a driven member as the first cam member rotates, and a second cam member configured to contact the driving member after an electrification to the driving source is stopped so as to rotate the first cam member in a second rotational direction opposite to the first rotational direction.

A driving apparatus includes a driving source supplied with a power and configured to generate a driving force, a first cam member configured to rotate in a first rotational direction in accordance with the driving force from the driving source, a driving member configured to drive a driven member as the first cam member rotates, and a second cam member configured to contact the driving member after an electrification to the driving source is stopped so as to rotate the first cam member in a second rotational direction opposite to the first rotational direction.

An imaging apparatus includes a second mount configured to bayonet-couple with a first mount. The second mount has multiple contact points disposed in a circumferential direction that are to be electrically connected to multiple contact faces on the first mount when coupled. The number of the contact points is an even number of four or larger. When viewing the imaging apparatus in a normal position from the second mount side, a line extending from a center axis of the second mount in the gravitational direction and an opposite direction is a first mount center line, and a line orthogonal thereto is a second mount center line. The contact pins include a first contact pin that overlaps the first mount center line, and second and third contact pins at both ends in the circumferential direction of the second mount, with generally the same distance to the second mount center line.

An imaging apparatus includes a second mount configured to bayonet-couple with a first mount. The second mount has multiple contact points disposed in a circumferential direction that are to be electrically connected to multiple contact faces on the first mount when coupled. The number of the contact points is an even number of four or larger. When viewing the imaging apparatus in a normal position from the second mount side, a line extending from a center axis of the second mount in the gravitational direction and an opposite direction is a first mount center line, and a line orthogonal thereto is a second mount center line. The contact pins include a first contact pin that overlaps the first mount center line, and second and third contact pins at both ends in the circumferential direction of the second mount, with generally the same distance to the second mount center line.

A control device including: a main subject detection unit that detects a first main subject from among subjects included in a first image, and acquires main subject information indicating the first main subject; a distance information calculation unit that detects a distance of a subject included in a first image, and acquires first distance information indicating the distance; and a detection unit that detects a distance within which a first main subject is included on the basis of main subject information and first distance information, and acquires main subject distance information indicating the distance within which the first main subject is included.