Patent ID: 8149257

Claim:
A printer that includes printing means provided on a conveying path of a recording sheet and sheet feed means provided on the downstream and upstream sides of the printing means in a conveying direction of a recording sheet, and performs color printing by superimposing ink colors while reciprocating and conveying the recording sheet by the sheet feed means, the printer comprising: a platen roller that is rotationally driven in normal and reverse directions by a driving force of a drive source, and includes a platen gear mounted at one end of a rotating shaft of the platen roller; a first sheet feed roller that is provided on the upstream side of the platen roller in the conveying direction of the recording sheet so as to be rotationally driven in normal and reverse directions by a driving force of the drive source, and includes a first sheet feed gear mounted at one end of a rotating shaft of the first sheet feed roller; a second sheet feed roller that is provided on the downstream side of the platen roller in the conveying direction of the recording sheet so as to be rotationally driven by a driving force of the drive source, and includes a second sheet feed gear mounted at one end of a rotating shaft of the second sheet feed roller; a first branch transmission gear group that is provided on a power transmission path between the platen gear and the first sheet feed gear and includes one or more gears transmitting the driving force of the drive source; a second branch transmission gear group that is provided on a power transmission path between the platen gear and the second sheet feed gear and includes one or more gears transmitting the driving force of the drive source; and thrust amount adjusting means for adjusting movable distances that are caused by the thrust of first and second idler gears, wherein a tooth trace of one of the gears of each of the first and second branch transmission gear groups has an inclination angle with respect to an axial direction, and the first and second branch transmission gear groups are formed of the first and second idler gears including inclined gear portions of which inclined directions of tooth traces are the same as each other.