Epson Scan 2500 Paper Feeding Mechanism, Motor Control for Each Mode PF Motor Specifications

EPSON Stylus Scan 2500 Revision A

2.2.4 Paper Feeding Mechanism

The paper feeding process begins at the ASF, continues through the PF roller, and ends at the paper eject roller (and star-wheel gear).

1

A

The ASF unit, which is common with the Stylus COLOR 740 printers, is driven by the PF motor (stepping motor). Torque sent from this motor switches between the ASF unit and pump/PF roller depending on the position of the disengage lever (described later).

In the EPSON Stylus Scan 2500, a four-phase hybrid type pulse motor is used in the PF motor as a motive power of the paper mechanism. The torque is sent at 2-Double 1-2, Double 1-2, 1-2, and 2-2 phase drives. This motor drives the paper-feeding mechanism as well as the pump mechanism which is necessary for printhead cleaning. By using this pulse motor, it becomes possible to use variable drive levels for many purposes, such as paper feed, slight paper feed, and high or low speed absorption of pump operations. The following table shows PF motor specifications.

2 /A

Rotor

3

B

4

/B

Figure 2-7. PF Motor Internal Circuit Diagram

Motor Control for Each Mode

	PF Motor Specifications				Printing mode	Drive Speed	Drive frequency		Drive method
						[CPS]	[PPS]
	Item		Description		High Speed Skip	340	4080		Double 1-2, 2-2,1-2
									phase drive*
Motor type		4-phase/200-pole Stepping motor
									Double 1-2, 2-2 phase
Drive voltage		42VDC ± 5%			Normal Printing	200	2400
									drive
Coil Resistance		7.8 Ohms ± 10%(per 1 phase under 25°C
									2-Double 1-2, 2-2 phase
		environment)			Capping	80	960
									drive
Control method		Bi-Polar Drive
					Wiping	40	480		2-Double1-2, 2-2 phase
Phase drive		1-2, 2-2, Double 1-2, 2-Double 1-2
									drive
		Phase drive			Cap (Valve	20	240		4-Double1-2, 2-2 phase
					Release)				drive
	Phase Drive	Inch/pulse		mm/pulse	Withdrawal of cap	5	60		4-Double 1-2, 2-2 phase
									drive
	2-2	1/720		0.035	Drive from the PF motor is sent to the PF rollers and paper eject rollers as
	1-2	1/1440		0.018
					described below.
	Double 1-2	1/2880		0.0088	To the PF rollers:
	2-Double 1-2	1/5760		0.0044	PF motor pinion gear (CCW rotation)→ Gear 73.6 → PF rollers
					￿
Operating Principles								40
				Printer Mechanism Operation