Double star wheel for post-printing media control in inkjet printing

DETAILED DESCRIPTION Accordingly, it is an object of the invention to provide improved starwheel-type pinch wheels which can handle forces in the range of 0.
3 to 0.
6 Newtons without damaging newly printed media of various types and which provide adequate postprinting control across the full width of the media.
It is another object of the invention to provide a small diameter starwheel-type pinch wheel to be spring-loaded against a media surface which has been freshly printed by an injet printhead, without damaging the quality of the printed images which could typically be graphics, text, or combinations thereof.
A related object is to provide a double starwheel having a hub diameter of approximately 4.
5 mm which carries media-engaging peripheral teeth having a diameter of approximately 5.
9 mm.
A further object of the invention is to provide a crossbar assembly for carrying a plurality of small diameter starwheel-type pinch wheels which is easy to assemble and which can be carried as a unit with all of the starwheel-type pinch wheels in spring-loaded position.
Still another object of the invention is to provide guide means for directing the newly printed media into contact with the aforementioned starwheels at an optimum angle.
The invention provides for multiple pinch wheel assemblies which each carry a double star wheel for contacting the newly printed surface of media which passes between the double star wheel and a secondary drive roller, with the starwheel perimeters of each pinch wheel assembly having matching diameters and in-phase teeth to assure adequate media control without damaging the newly printed images or puncturing the media.
In one embodiment, such double star wheel is a unitary member with a spool-like shape having a hub of approximately 4 mm width which carries twin starwheels, each at an opposite end of the hub.
In a preferred form, the double star wheel is mounted on a pinch wheel assembly which allows relative up-and-down flexing between each of the twin starwheels to allow for variations in the shape and tolerances of the matching exit roller as well as variations in the freshly printed media passing therebetween