| 摘要 |
<p>A base lens blocking system comprises a blocking member (200) formed of a flange (202) with a rearward directed shank (204) received in a collet (232) of a spindle (236), preferably, a dead length, recessed collet. The front surface of the flange contains a lens blank engaging region (208) which can be recessed. The lens blank is applied to the flat, front surface of the flange by means of a disc of adhesive tape (307), either a thermoplastic adhesive or a double-sided pressure sensitive adhesive tape or a very thin film of wax applied to a heated surface of the flange under a pressure from 5-20 pounds. A batch of blocked lens blanks can be cut with base curves and processed to finished lenses without measuring the center thickness of the base curves of each lens.</p> |
