Ricoh improves printing image quality sharply on special paper, such as textured media, using AC transfer technology and an elastic fusing belt.
In recent years, the need for printing on-demand has expanded in commercial printing or in-house printing fields. Printing on-demand makes it possible to print the required number of copies when needed and at low cost using a high-mix low-volume printing movement. In the commercial printing field, the same response capabilities for many types of paper is required with offset printing. Especially, surface convexo-concave processed thick paper is used in many cases for the cover of prints etc. because of its unique texture, so there is a need to print on it.
Ricoh has developed a technology to enable image printing on textured media, thereby extending the types of paper that can be printed.
Generally electro-photographic printing uses a direct-current electric field (DC) to transfer toner from an image transfer belt onto paper. With textured media, which has convex-concaves on the surface, because the paper hollows between the concave part and the image transfer belt, toner is hard to transfer, and the image partially falls out. Ricoh developed a new technology to use an alternating-current electric field (AC), which produces a condition that enables toner to transfer easily to the concave portion of the paper.
Fig. 1: Flow image of DC transfer and AC Transfer
The toner transferred to the concave portion of textured media had a problem with improper fusing because the fusing belt could not respond to the concave portion. To overcome this problem, we thickened the elastic layer of the fusing belt and enabled the fusing belt to respond to the convexo-concaves of textured media (Fig. 2). This produced the required pressure and heat for fusing to be added to the paper (toner), and enabled good fusibility also on textured media. To prevent worsening of the thermo following property, especially in thickening the elastic layer, we used IH technology, which is excellent in thermal-response properties.
In this way, high definition, highly fusible printing was achieved also on textured media.
Fig. 2: Structure of elastic fusing belt