| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an optical element composed of optical ceramics, particularly, a lens, which enables the high-quality lens to be manufactured with high reproducibility in sufficient quantities at an acceptable cost. <P>SOLUTION: In the manufacture of a green body, at least one near-net-shape molding is applied at a molding stage. At the molding stage, when a mold is filled with a ceramic powder, a medium pressure of about 0.1-50 MPa, preferably 0.5-25 MPa, more preferably 1-12 MPa is applied onto either the powder batch or the ceramic powder batch, arranged in the mold. A molding method applied to the molding sage is selected from centrifugal slip casting and hot casting. The optical ceramics including a single particle with a cubic crystal structure has purity in which the content of impurities is 500 ppm or less and that of a transition metal is 250 ppm or less. <P>COPYRIGHT: (C)2008,JPO&INPIT |
