Wärmefixiergerät und -verfahren

摘要

A heat and pressure fusing apparatus for fixing toner images (20) to substrates (22) such as plain paper, the toner comprising a thermoplastic resin. The apparatus includes two nip forming members (26, 30) which cooperate to form a nip having an asymmetrical pressure profile. More particularly, the pressure profile through the nip, from entrance to exit, is such that toner images on a substrate passing through the nip are first subjected to relatively low pressure which continues until the toner begins to flow as a result of being heated. Once toner flow commences, the images are subjected to pressure high enough to force the toner into the substrate. The pressure profile of the nip can be varied to accommodate different fusing speeds for different processors.