| 摘要 |
PROBLEM TO BE SOLVED: To provide a sheet transport device with a simple structure at a low cost, which is capable of being stopped at a target stop position accurately using a digital position signal of an encoder having a resolution equal to the positioning resolution required. SOLUTION: Upon the detection of rotation of a motor driving a print sheet, an encoder pulse Y-FB is generated. According to the pulse, a driving signal PWM to the motor is changed. The driving signal PWM is held throughout holding time T2(ck) in timing X4 in which an object to be transported reaches the target position, then the signal is stopped in timing X5. Positioning accuracy is confirmed during a period before timing X6. The holding time is varied according to the number of trials to the target position. The driving signal is gradually increased before the target position, thereby enabling reliable sheet transport. COPYRIGHT: (C)2004,JPO&NCIPI
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