AMOUNT OF LIGHT ADJUSTMENT DEVICE AND OPTICAL APPARATUS

PROBLEM TO BE SOLVED: To improve durability of a light shielding blade without deteriorating acceleration of shutter speed.SOLUTION: An amount of light adjustment device includes: one or more sheets of an amount of light adjustment member whose driving source is a rotatable rotor magnet and that can advance or retreat relative to a light passage opening while rotating in response to rotation of the rotor magnet; a transmission member for transmitting rotation of the rotor magnet to the amount of light adjustment member; and an apparatus base for supporting a driving unit. An angle defined by the rotation direction of a drive pin provided with the transmission member and the operation direction of a cum provided with the amount of light adjustment member significantly changes and rotation speed of the amount of light adjustment member is changed by the rotational position of the rotor magnet.SELECTED DRAWING: Figure 6 【課題】シャッター速度の高速化を損なうことなく、遮光羽根の耐久性を向上させる。【解決手段】回転可能なロータマグネットを駆動源とし、前記ロータマグネットの回転に応じて回動しつつ光通過口に対して進退可能な１枚以上の光量調節部材と、ロータマグネットの回転を前記光量調節部材に伝える伝達部材と、駆動ユニットを支持する装置基板と、を備え、伝達部材に設けられた駆動ピンの回転方向と光量調節部材に設けられたカムの動作方向とのなす角が大きく変わり、光量調節部材の回動スピードがロータマグネットの回転位置によって変化させている。【選択図】図６