Paper thickness compensation in a printer
View Patent ↗In a printer, page thickness is compensated for by measuring a displacement between a printhead and a print media support surface. A sensor flag engages a surface of said print media and provides an indication to an optical sensor of the displacement. The print media support surface may be a platen having a non-constant radius such that rotation of the platen adjusts the displacement between a contact surface of the platen and a the printhead.
1. A printer comprising:
a printhead;
a print media support surface for supporting print media during printing;
an optical sensor to measure a displacement between said print surface and said printhead, and
means to adjust the displacement between said print surface and said printhead;
wherein the optical sensor senses the position of a pivotal sensor flag that engages a surface of said print media and wherein the sensor flag is mounted upon a biased shaft mounted to the printhead.
2. The printer of claim 1 wherein said print media support surface comprises a platen mounted so as to rotate about a longitudinal axis thereof, said platen comprising a contact surface extending along the platen parallel with said axis, said contact surface at a non-constant radius about a circumference of said platen such that rotation of the platen effects the offset of said print surface with respect to said printing nozzles.
3. The printer of claim 1 wherein the printhead is a pagewidth printhead.
4. The printer of claim 3 wherein the printmedia support surface extends the width of the pagewidth printhead.