| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent the generation of scratches and digs harmful in the working of a glass ball, to stably produce a desired surface shape, further to eliminate defects of cracks, hollows and strains in the surface of a lens after forming as standard values required for the glass ball, and to make influence on the resolution of an image hard to appear. <P>SOLUTION: The glass ball has a ball diameter of ≥0.1 mm. Regarding surface shape precision, a size variation in diameter of a lot is set to 0.01 to 60 μm, a sphericity is set to 0.01 to 60 μm, a surface roughness (Ra) is set to 0.001 to 0.010 μm, scratches in the surface are controlled to ≤500 μm, and also, digs are controlled to ≤300 μm. <P>COPYRIGHT: (C)2007,JPO&INPIT |
