Blade-driving device, optical device, and method for producing arm

1. A blade-driving device comprising: a board including an opening;

a blade opening and closing the opening;

an arm driving the blade and made of a synthetic resin;

a drive member driving the arm;

a connection pin connecting the arm and the blade, wherein the arm and the reinforcement member include through holes through which the connection pin commonly penetrates;

a laser welding mark formed in such a direction as to arrange an insertion hole and the through hole, wherein the arm and the reinforcement member include insertion holes into which a drive pin is commonly inserted; and

a reinforcement member formed with the laser welding mark indicating a mark formed by laser welding

the reinforcement member and the arm together, and made of a synthetic resin,

wherein the reinforcement member has a thin plate shape.

2. The blade-driving device of claim 1 , wherein the drive member includes a drive pin movable

within a predetermined range,

the arm and the reinforcement member include insertion holes into which the drive pin is commonly inserted,

the laser welding mark includes a region intersecting with a movable direction of the drive pin.

3. The blade-driving device of claim 2 , wherein the region is formed to be evenly spaced from an edge portion of the insertion hole.

4. The blade-driving device of claim 3 , wherein the edge portion has a linear shape,

the region is parallel to the edge portion.

5. The blade-driving device of claim 2 , wherein the laser welding mark is formed along one half or more of a periphery of the insertion hole.

6. The blade-driving device of claim 1 , wherein the arm is rotatably supported about a

predetermined fulcrum,

the blade includes plural blades,

the connection pin includes plural connection pins connecting the respective plural blades and the arm,

the through holes of the arm and the reinforcement member are penetrated by the connection pin closest, among the plural connection pins, to the fulcrum of rotation of the arm.

7. The blade-driving device of claim 6 , wherein the plural connection pins have the same shape.

8. The blade-driving device of claim 1 , wherein the reinforcement member is thinner than the arm.

9. The blade-driving device of claim 1 , wherein the reinforcement member is provided on a surface, of the arm, opposite to a surface facing the blade.

10. An optical device comprising: a board including an opening;

a blade opening and closing the opening;

an arm driving the blade and made of a synthetic resin;

a drive member driving the arm;

a connection pin connecting the arm and the blade, wherein the arm and the reinforcement member include through holes through which the connection pin commonly penetrates;

a laser welding mark formed in such a direction as to arrange an insertion hole and the through hole, wherein the arm and the reinforcement member include insertion holes into which a drive pin is commonly inserted; and

a reinforcement member formed with the laser welding mark indicating a mark formed by laser welding

the reinforcement member and the arm together, and made of a synthetic resin,

wherein the reinforcement member has a thin plate shape.

11. A method for producing an arm for driving a blade opening and closing an opening of a board, comprising:

commonly inserting a jig into insertion holes respectively formed in an arm and a reinforcement member;

inserting a jig into through holes respectively formed in the arm and the reinforcement member and different from the insertion holes;

laser welding the arm and the reinforcement member having a thin plate shape such that a laser welding mark is formed in such a direction as to arrange the insertion hole and the through hole;

commonly inserting a connection pin connecting the arm and the blade through the through holes; and

commonly inserting a drive pin of a drive member into the insertion holes.