Tinting of Plastic Eyeglass Lens using Laser

Abstract

This paper reports about tinting of polycarbonate (PC) eyeglass lens with laser. We have developed laser tinting using violet laser diode (VLD) and a CO2 laser. In order to dye eyeglass lens uniformly, it is important to spread disperse dyestuff on lens and plates. We selected the sublimation transfer tinting without contact, which was used as one of the technologies that spread dyestuff on the PC surface thinly. We have tested line tinting (200um) of PC plate(t=2 mm) with the sublimation transfer tinting without contact using VLD. Uniform tinting in small area(approximately 1x2 mm2) was achieved by scanning VLD light. The uniform tinting of large area was expected, so we tried to dye PC lens which is used widely. In order to dye wide area, we used a CO2 laser while eliminating the melt of the lens surface by the defocus. Recently, high refractive index lens are widely used, but it is very difficult to dye high refractive index lens uniformly. The dyestuff layer was thinly spread on the surface of the high refractive index lens by using the sublimation transfer tinting without contact, and uniform tinting on the lens were achieved by the CO2 laser.