| 摘要 |
PROBLEM TO BE SOLVED: To prevent the deformation of a glass workpiece caused by the own gravity when the surface roughness of the glass workpiece is made small by heating, and to obtain a glass lens having a final shape by performing processes from surface-smoothing to press-shaping in one heating zone. SOLUTION: A glass material 26 is mounted on a holder arm 27 in a mold, and the glass material 26 is heated to a temperature not lower than the glass transition point and not higher than the yield point while controlling heaters 24, 25 as preliminary heating. An upper mold 22 and a lower mold 23 heated to a temperature higher by 200°C or more than the yield point are brought close to the glass material 26 and the both surfaces 26a, 26b of the glass material are heated to a temperature not lower than the yield point. By this heating, the surface roughness Rmax of the glass material 26 is reduced to 0.04μm or less. The temperature of the heater 25 is lowered, and when the temperature of the mold becomes higher by about 20°C than the yield point, the glass material 26 is placed on the lower mold 23 by subjecting the holder arm 27 to lowering rotation. The upper mold 22 is allowed to descend, and after press-shaping, the desired glass lens is obtained by cooling. COPYRIGHT: (C)2005,JPO&NCIPI
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