A driving apparatus which is capable of smoothly moving a follower by a cam portion, and realizes the stopper structure of the follower by a small number of components without the size increased. The driving apparatus comprises an up cam gear having an up radial cam and an up thrust cam, and a down cam gear unit having a down radial cam and a down thrust cam. The up cam gear and the down cam gear unit mesh with each other in a vicinity of a region in which a lift amount of the up radial cam with respect to the follower increases. In a vicinity of a position at which the up cam gear and the down cam gear unit mesh with each other, a lift amount of the up thrust cam is larger than a lift amount of the down thrust cam in the thrust direction.

There is provided a blade drive device including a substrate that has an opening, a front curtain and a rear curtain that are movable along an opening surface of the opening so as to open and close the opening, a front curtain locking portion that interlocks with opening and closing operations of the front curtain, a rear curtain locking portion that interlocks with opening and closing operations of the rear curtain, and a regulation lever that is configured to be pivotally movable around a lever axis, and that is capable of entry and escape between an entry position which enters each operation trajectory of the front curtain locking portion and the rear curtain locking portion in response to the opening and closing operations of the front curtain and the rear curtain and an escape position escaped from the operation trajectory. The regulation lever has a front curtain regulation portion which can be locked by the front curtain locking portion from one side around the lever axis at the entry position so as to regulate movement of the front curtain in a closing direction, and a rear curtain regulation portion which can be locked by the rear curtain locking portion from the other side around the lever axis at the entry position so as to regulate movement of the rear curtain in a closing direction.

A driving apparatus which is capable of smoothly moving a follower by a cam portion, and realizes the stopper structure of the follower by a small number of components without the size increased. The driving apparatus comprises an up cam gear having an up radial cam and an up thrust cam, and a down cam gear unit having a down radial cam and a down thrust cam. The up cam gear and the down cam gear unit mesh with each other in a vicinity of a region in which a lift amount of the up radial cam with respect to the follower increases. In a vicinity of a position at which the up cam gear and the down cam gear unit mesh with each other, a lift amount of the up thrust cam is larger than a lift amount of the down thrust cam in the thrust direction.

There are provided a blade drive device and an optical instrument. The blade drive device includes a substrate that has an opening, a front curtain and a rear curtain that are movable along an opening surface of the opening so as to open and close the opening, a front curtain locking portion that interlocks with opening and closing operations of the front curtain, a rear curtain locking portion that interlocks with opening and closing operations of the rear curtain, a regulation lever that is configured to be pivotally movable around a lever axis, that enters an operation trajectory of the front curtain locking portion and the rear curtain locking portion, and that is capable of entry and escape between an entry position for regulating the movement of the front curtain and the rear curtain in a closing direction and an escape position escaped from the operation trajectory, a regulation electromagnetic actuator that is configured to be rotatable around a regulation axis, and a linkage lever that causes the regulation lever to pivot around the lever axis in response to the rotation around the regulation axis of the regulation electromagnetic actuator. The regulation lever and the linkage lever engage with each other while being provided with play in a circumferential direction around the regulation axis.

A focal-plane shutter capable of stabilizing a curtain in continuous photographing action for suppression of variation in light exposure period is provided. The focal-plane shutter includes a base plate having a first opening, a blade receiving plate so arranged as to face the base plate and having a second opening formed in a position corresponding to the first opening, and a rear curtain that is arranged between the base plate and the blade receiving plate and moves between an open position where the first opening and the second opening are open and a closed position where the first opening and the second opening are closed to open and close the first opening and the second opening. The blade receiving plate has a protruding section in a position where the blade receiving plate overlaps with the rear curtain located in the open position when viewed along the optical axis direction, and the protruding section so protrudes toward the rear curtain as to allow the rear curtain to come into contact with the protruding section.

A focal-plane shutter capable of stabilizing a curtain in continuous photographing action for suppression of variation in light exposure period is provided. The focal-plane shutter includes a base plate having a first opening, a blade receiving plate so arranged as to face the base plate and having a second opening formed in a position corresponding to the first opening, and a rear curtain that is arranged between the base plate and the blade receiving plate and moves between an open position where the first opening and the second opening are open and a closed position where the first opening and the second opening are closed to open and close the first opening and the second opening. The blade receiving plate has a protruding section in a position where the blade receiving plate overlaps with the rear curtain located in the open position when viewed along the optical axis direction, and the protruding section so protrudes toward the rear curtain as to allow the rear curtain to come into contact with the protruding section.