Nidec Copal Corporation

Yutaka Okazaki

Takao Ogawa

Shuji Ichinose

A focal plane shutter apparatus is constructed by a light shielding blade, a fitting pin attached to the blade and an arm which is slidably engaged with the fitting pin to open or close the blade. A surface hardness of the fitting pin is higher than that of the arm. Concretely, the surface hardness of the arm is Hv300 to 600, and the surface hardness of the fitting pin is Hv450 to 1000. The arm and the fitting pin are subjected to chemical polishing treatment. Furthermore, the fitting pin is plated with nickel, chromium, palladium or rhodium. The fitting pin and arm have a substantially equal material hardness, or the material hardness of the fitting pin is higher. As the case may be, the fitting pin or arm may be plated with gold. Such an arrangement can suppress generation and accumulation of abrasion powder in the focal plane shutter apparatus assembled into a digital camera.

Focal plane shutter apparatus

A focal plane shutter has a light shielding shutter blade. A blade dowel is attached to the shutter blade. A blade arm is slidably engaged with the blade dowel to open or close the shutter blade. A surface hardness of the blade dowel is higher than a surface hardness of the blade arm. The surface hardness of the blade arm is Hv300 to 900, and the surface hardness of the blade dowel is Hv450 to 1000. The blade arm and the blade dowel are subjected to chemical polishing treatment. The blade dowel is plated with nickel, chromium, palladium or rhodium. A material of the blade dowel is a free-cutting stainless steel or a carbon tool steel, and a material of the blade arm is a carbon tool steel or a titanium material.

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Koriyama, Japan

Yutaka Okazaki