Multiple-feed detection (EF) The envelope feeder detects the multiple-feed of the envelopes to prevent the product damage from massive multiple-feed. The envelope feeder driver monitors the envelope multiple-feed sensor (PS1802) to detect up and down motion of the upper separation roller. During a normal-feed operation, the envelope multiple-feed sensor flag interrupts the multiple-feed sensor. If more than four multiple-fed envelopes are placed between the upper separation roller and the lower separation roller, the upper separation roller rises approximately 0.7mm (almost equivalent to the thickness of four envelopes).
This causes the multiple-feed sensor flag not interrupting the sensor and the envelope feeder driver detects the multiple-feed of envelopes. NOTE: The multiple-feed detection mechanism is not able to detect less than four multiple-fed envelopes (approximately 0.7 mm), however, it does not affect the product damage. The envelope feeder driver notifies the pickup jam to the DC controller when it determines a multiple feed.
Figure 1-39 Envelope feeder multiple-feed detection Envelope multiple-feed sensor (PS1802) Upper separation roller Envelope multiple-feed sensor flag Lower separation roller Multiple-fed envelope Jam detection (EF) The envelope feeder uses the following sensors to detect the presence of media and to check whether media is being fed correctly or has jammed ENWW Envelope feeder 51