Laser Toner Fusion: An Imaging Process for Graphic Arts Applications

Abstract

Laser-toner-fusion (LTF) is a dry, high quality electrothermographic imaging process for producing both monochrome and color images from electronic input. The process steps involve using a magnetic brush to apply a uniform toner layer to a substrate imagewise exposing the layer to a high power IR laser that tacks the toner to the substrate; removing the unexposed toner using a magnetic brush toner removal device; and finally, fixing the image using conventional fusing. The removed unexposed toner can be recycled thereby eliminating waste. The exposed toner particles are partially buried in a thermoplastic layer and are therefore robust to abrasion. The process is insensitive to visible radiation and can be carried out in ordinary roomlights. The energy required for imaging is between 150 and 300 mJ/cm2. The application most thoroughly investigated is image setting where color separations with 2540 pixels per inch resolution, and with transmission density of 4.0, have been made to produce high-quality 4-color images.