Light amount adjustment apparatus having plurality of plate-like light-shielding blade members and method of manufacturing the light-shielding blade members
A light amount adjustment apparatus having a plurality of light-shielding blade members that can be so manufactured by simple machining as to reduce undesired reflection on end faces of the light-shielding blade members which are parallel with the optical axis and prevent degradation in image quality such as flare and ghosts. A driving force of a stepping motor is transmitted to the light-shielding blade members so that an aperture diameter can be changed. The light-shielding blade members are formed by injection molding of a light-shielding resin material. By performing blasting on an end face of each light-shielding blade member in a part that forms the aperture diameter, an aperture end face whose surface is roughened while substantially maintaining outside dimensions of the light-shielding blade member is formed, and an oblique portion tilted relative to the aperture end face is formed.
1. A light amount adjustment apparatus comprising:
a driving source; and
a plurality of light-shielding blade members to which a driving force of said driving source is transmitted to change an aperture diameter,
wherein said light-shielding blade members are formed by injection molding of a light-shielding resin material, and
wherein by performing blasting on an end face of said light-shielding blade member in a part that forms the aperture diameter, an aperture end face whose surface is roughened while substantially maintaining outside dimensions of said light-shielding blade member is formed, and an oblique portion tilted relative to the aperture end face is formed.
2. A light amount adjustment apparatus comprising:
a driving source; and
a plurality of light-shielding blade members to which a driving force of said driving source is transmitted to change an aperture diameter,
wherein said light-shielding blade members are formed by punching a light-shielding plate material, and
wherein by performing blasting on an end face of said light-shielding blade member in a part that forms the aperture diameter, an aperture end face whose surface is roughened while substantially maintaining outside dimensions of said light-shielding blade member is formed, and an oblique portion tilted relative to the aperture end face is formed.
3. A method of manufacturing a light-shielding blade member, comprising:
a step of performing injection molding of a light-shielding resin material;
a step of fixing, on a fixing member, a light-shielding blade member formed by injection molding of the resin material in said injection molding step; and
a step of performing blasting on an end face of the fixed light-shielding blade member in a part that forms an aperture diameter,
wherein when fixing, on the fixing member, the light-shielding blade member formed by injection molding, the light-shielding blade member formed by injection molding is fixed on the fixing member such that the fixing member is exposed outside the part of the light-shielding blade member formed by injection molding which forms the aperture diameter.
4. A method of manufacturing a light-shielding blade member according to claim 3 ,
wherein when performing blasting, nonmetallic particles or metallic particles are caused to collide from a direction tilted at a predetermined angle from a direction perpendicular to a plane of the fixing member to a direction in which the plane of the fixing member is exposed.
5. A method of manufacturing a light-shielding blade member according to claim 4 ,
wherein the blasting comprises wet blasting.
6. A method of manufacturing a light-shielding blade member, comprising:
a step of punching a light-shielding plate material;
a step of fixing, on a fixing member, a light-shielding blade member formed by punching the plate material in said pinching step; and
a step of performing blasting on an end face of a part of the fixed light-shielding blade member which forms an aperture diameter,
wherein when fixing, on the fixing member, the light-shielding blade member formed by punching, the light-shielding blade member formed by punching is fixed on the fixing member such that the fixing member is exposed outside the part of the light-shielding blade member formed by punching which forms the aperture diameter.
7. A method of manufacturing a light-shielding blade member according to claim 6 ,
wherein when performing blasting, nonmetallic particles or metallic particles are caused to collide from a direction tilted at a predetermined angle from a direction perpendicular to a plane of the fixing member to a direction in which the plane of the fixing member is exposed.
8. A method of manufacturing a light-shielding blade member according to claim 7 ,
wherein the blasting is blasting using wet blasting.