Patent ID: 9239511
Filing Date: 2016-01-19
CPC Classification: G03B

Claim Text:
1. A focal plane shutter comprising: a board including an opening; blades opening and closing the opening; an electromagnet supported by the board; a drive lever adsorbed to and held by the electromagnet, and swingably supported by the board; a drive arm connected to the drive lever, swingably supported by the board, and driving the blades; a first biasing member always biasing the drive lever away from the electromagnet and moving the blades; a first adjusting member that stepwisely adjusts a biasing force of the first biasing member; a second biasing member always biasing the drive arm in a direction opposite to a biasing direction of the first biasing member to such an extent that the blades are moved in accordance with the biasing force of the first biasing member; and a second adjusting member that steplessly adjusts a biasing force of the second biasing member.