| 摘要 |
PURPOSE: To facilitate the replacement of ink jet heads while enhancing image quality by providing marks to a plurality of ink jet heads corresponding to respective colors and measuring the time distances between the heads on the basis of the detection results of the marks and controlling the printing timings by the respective heads on the basis of the measuring results. CONSTITUTION: When the times (times between heads) required in the movement over the respective distances L1, L2, L3 between heads 5Y, 5M, 5C, 5B are set to T1, T2, T3, a mark sensor 21 is provided at a position capable of detecting marks 20 in the constant speed region Vc (main scanning speed) of the recording heads 5. Therefore, the times T1, T2, T3 between the heads required in the movement of the heads over the distances L1, L2, L3 between the heads 5Y, 5M, 5C, 5B can be directly obtained without performing correction processing. Then, a timer is started in the rising timing of a mark detection signal to measure the time up to the next rising timing to obtain each head time. |
