Patent ID: 8506187

Claim:
A printing apparatus comprising: a thermal recording paper conveyance mechanism which conveys thermal recording paper along a paper conveyance path; a first thermal head which is provided along the paper conveyance path, and is arranged to face a first surface side of the paper conveyance path; a first platen roller which is arranged to face the first thermal head across the paper conveyance path; a first spring that presses the first thermal head toward the first platen roller with a first force; a second thermal head which is provided along the paper conveyance path and on a supply side of the thermal recording paper with respect to the first thermal head, and is arranged to face a second surface side of the paper conveyance path; a second platen roller which is arranged to face the second thermal head across the paper conveyance path, wherein a friction coefficient in a region of the first platen roller which is in contact with the thermal recording paper is smaller than a friction coefficient of the second platen roller; a second spring that presses the second thermal head toward the second platen roller with a second force; a drive mechanism which drives the first platen roller and the second platen roller; and feed operation selecting means for placing priority on a feed operation of one of the platen rollers to a feed operation of the other platen roller, when the first platen roller differs from the second platen roller in a feed speed of the thermal recording paper, wherein the first thermal head, the second platen roller, a first idler gear and the drive mechanism are arranged in a printer body of the printing apparatus, and the second thermal head, the first platen roller and a second idler gear are arranged in a printer cover of the printing apparatus, wherein the first idler gear is arranged between the second platen roller and the first thermal head while engaging the second platen roller and the second idler gear, and the second idler gear is arranged between the first platen roller and the second thermal head while engaging the first platen roller and the first idler gear.