BENT GLASS PLATE FOR OPTICAL USE AND FABRICATION METHOD THEREOF

摘要

With conventional bent glass plates and fabricating method thereof, it has been difficult to fabricate bent glass plates with high productivity while achieving both high shape precision and high surface smoothness. According to the present invention directed to a glass plate with 2 mm or less thickness, a bent glass plate for optical use with a shape precision PV value of 50 um or less and a surface roughness Ra value of 5 nm or less was achieved by appropriately controlling the temperature of the glass plate, the temperatures of upper and lower press dies, and the press pressure; and quickly and uniformly cooling the glass plate to a predetermined temperature.

主权项

1. A bent glass plate for optical use fabricated by using a method wherein a glass plate with a thickness of 2 mm or less is heated to a glass transition temperature (Tg) or higher, and press-molded by a pair of preheated press dies to transfer surface shapes of the pair of press dies to the glass plate to produce the bent glass plate with a PV value of 50 μm or less and a Ra value of 5 nm or less, wherein die PV value represents shape precision and the Ra value represents surface roughness.