| 摘要 |
PROBLEM TO BE SOLVED: To form the image at the correct position by detecting the pattern on a transfer paper by a sensor provided on a transfer paper discharge passage to judge the deviation of the installation position of a roll paper, and adjusting the range of the pattern detection error with the sensor with an arbitrary value to detect the deviation of the roll paper. SOLUTION: In exchanging a roll paper, a write part 201 writes the prescribed pattern (e.g. the pattern of alternate arrangement of black and white parallel to the carrying direction of the roll paper) capable of being detected by a sensor 214 in a place not overlapped on the image data, e.g. in a tip center part of the roll paper, and the written data are developed together with the image data, and printed on the transfer paper. Before the timing at which the transfer paper passes through a fixing roller 21 and is discharged, the output of the sensor 214 is referred to judge whether the transfer paper is in the normal position or deviated in the right-to-left direction. The reference value to judge the black pattern or the white pattern according to the output value of the sensor 214 can be set, and the detection error range can be set narrow or wide. |
