Image forming device regulating sheet conveying timings

摘要

An image forming device having a sheet conveying path extending from a feeder unit to an image forming unit. In the feeder unit, a sheet supply roller is rotated at a peripheral speed Vs. A convey roller positioned immediately downstream of the sheet supply roller is rotated at a peripheral speed V3 lower than Vs. Additional convey roller positioned immediately downstream of the first convey roller it rotated at a peripheral sped V2 lower than V3. A register roller positioned downstream of the second convey roller is rotated at a peripheral speed V1 lower than V2. A transfer roller of the image forming unit is rotated at a peripheral speed V0 lower than V1. Bach convey roller, the register roller, the sheet supply roller is connected to each clutch. Sheet sensors are provided each positioned between neighboring rollers for detecting a leading edge of the sheet. Upon detection of the leading edge by one of the sensors, the roller positioned immediately upstream of the one of the sensors is shifted to its non-driving state by the clutch associated therewith.