| 摘要 |
PROBLEM TO BE SOLVED: To enhance accuracy in subscanning feed of a recording sheet. SOLUTION: The image forming apparatus is arranged to feed a recording sheet in the subscanning direction by rotary driving a platen roller shaft 15a by means of a feed motor 35 through a reduction mechanism 36. Different intermediate shafts 61 and 62 in the gear train 36a of the reduction mechanism 36 are provided with a first encoder 65 and a second encoder 66. The first encoder 65 and the second encoder 66 are provided with discs 67 and 70 having slits 67a and 70a in the outer circumference. The disc 70 of the second encoder 66 has a slit pitch P2 set smaller than the slit pitch P1 of the first encoder 65. The second encoder 66 has a fixing shaft 62 located on the speed increasing side as compared with the fixing shaft 61 of the first encoder 65. Rotation of the platen roller 15 is controlled based on the outputs from two encoders. The recording sheet can thereby be fed with a high accuracy by the pulse from the second encoder 66. COPYRIGHT: (C)2004,JPO
|
