| 摘要 |
PURPOSE:To improve plane accuracy by forming a square pipe of which the inside surfaces at the four corners are deformed along the outside surfaces of a columnar jig having the tapered or rounded surfaces at the four corners so as to have the rounded or tapered surfaces. CONSTITUTION:A bottomed square glass cell 10 is made into the construction in which optically polished light transmittable plates 13 are welded to parallel side wall plates 12 closed at the bottom ends by bottom parts 11. Projecting parts 14 are integrally formed to the inside surfaces at both side ends of the plates 12 and the inside surfaces of the parts 14 are tapered or rounded 15. The optically polished light transmittable plates 13 are welded to both ends of such plates 12 by which the inside surfaces at four corners are tapered or rounded. The plane accuracy is thus improved while the loss of transparency is prevented by the constitution in which the light transmittable plates are separately formed and are welded. |
