Compact imaging roll printer

Abstract

A compact printer includes a print roll on which a latent image is deposited, toned, then heated and transferred in a 'transfuse' step. A commutating heater selectively heats a surface sector of the rotating roll for transfusing the image and roll cleaning, and the roll body remains below a toner agglomeration temperature. The roll has a rigid core and a surface structure that includes a plurality of heater lines and a hardcoated elastomeric imaging layer covering the heater lines. The imaging layer includes a conductive sublayer and a dielectric surface layer, both having greater thermal conductivity than an outer region of the core so that heat from the heaters preferentially flows to the deposited toner image. The printer scrolls portions of a latent image, which is toned, heated and transferred onto a separate recording member to form a final image having, in general, a much greater surface area than the roll. Preferably a blower cools the core, establishing a thermal equilibrium well below a toner melt temperature. A stepper motor engages the core to rotate it, and position signals from the stepper drive coordinate deposition of the latent image and feeding of the recording sheet. The roll, which may be under two inches in diameter, undergoes repetitive thermal cycling, with fusing heat traveling preferentially to the surface in a limited sector, and residual heat traveling to the core after the toner is removed.