Lens holding tool

Abstract

A lens holding tool includes a head portion and a pin that supports the head portion rotatably. The pin includes: a shaft portion having an exhaust outlet therein; a protruding portion that protrudes outwardly from the shaft portion; a sealing member disposed on the protruding portion; and a supporting portion that has a partially spherical shape and is disposed on a leading end of the shaft portion. The head portion includes: a workpiece receiving portion that holds a workpiece; an internal space that accommodates the protruding portion; an opening that has a diameter larger than a diameter of the shaft portion and smaller than an outer diameter of the protruding portion, the internal space communicating with an outside of the head portion through the opening; a suction hole through which the internal space communicates with the workpiece receiving portion; and an end receiving portion on which the supporting portion abuts.

What is claimed is: 
     
         1 . A lens holding tool comprising:
 a head portion that holds an optical member as a workpiece; and   a pin that supports the head portion rotatably,   wherein the pin comprises:
 a shaft portion having an exhaust outlet therein; 
 a protruding portion that protrudes outwardly from the shaft portion; 
 a sealing member disposed on the protruding portion; and 
 a supporting portion that has a partially spherical shape and is disposed on a leading end of the shaft portion, 
   the head portion comprises:
 a workpiece receiving portion that holds the optical member; 
 an internal space that accommodates the protruding portion; 
 an opening that has a diameter larger than a diameter of the shaft portion and smaller than an outer diameter of the protruding portion, the internal space communicating with an outside of the head portion through the opening; 
 a suction hole through which the internal space communicates with the workpiece receiving portion; and 
 an end receiving portion that allows the supporting portion to abut thereon, wherein 
   a distance between an internal wall surface of the head portion and a bottom surface of the internal space decreases outwardly from an edge of the opening.   
     
     
         2 . The lens holding tool according to  claim 1 , wherein when the pin suspends and holds the head portion, the sealing member abuts on the internal wall surface of the head portion so as to seal the opening. The lens holding tool according to  claim 1 , wherein the internal wall surface has a shape of a spherical zone. 
     
     
         4 . The lens holding tool according to  claim 1 , wherein the internal wall surface has a shape of a side surface of a circular truncated cone. 
     
     
         5 . The lens holding tool according to  claim 4 , wherein the sealing member is arranged such that, when the supporting portion abuts on the end receiving portion and a central axis of the pin matches a central axis of the head portion, a perpendicular from a spherical center of the supporting portion to the internal wall surface passes through a center of a cross section of the sealing member.