Epson Scan 2500 Ink System, Pump, Carriage Lock, Head Cleaner Mechanism, Pump roller Cap unit

EPSON Stylus Scan 2500 Revision A

2.2.5 Ink System

Ink system mechanism consists of 1) cap mechanism, 2) pump mechanism, 3) carriage lock mechanism, 4) waste ink absorber and 5) ink sequence. Out of these mechanisms, 1) to 4) are physical mechanism and parts which are mounted on the printer mechanism and 5) the ink sequence is performed automatically by the firmware. The EPSON Stylus Scan 2500 has no engage/ disengage mechanism, meaning the pump and platen are always at work when the PF motor operates. The figures below show printhead positions when the ink system and various ink-pumping sequences are performed.

Eject roller	PF roller drive
	gear
drive gear

Carriage lock

lever

Cleaner blade

Eject roller	PF (pump)
transmission
	motor pinion
gear
	gear

Pump roller

Cap unit

Figure 2-13. Ink System Mechanism

Printable Area

2976 dots (360-dpi)

A BC D E F

A. ASF Pick-up position

B. Flushing position

C. Wiping/rubbing position

D. Flushing position

E. Ink Discharge position

F. Cap cleaning position

Figure 2-14. Major Ink Sequence Positions on Carriage

2.2.6Pump, Carriage Lock, Head Cleaner Mechanism

In the EPSON Stylus Scan 2500, there is no switch or mechanism to switch between the ink pump and paper feed operations. Therefore, whenever the paper feed/pump motor rotates, the pump-drive roller inside the pump unit rotates. However, the rotational direction of the rollers determines whether or not the pump sucks ink. Also, even if the pump rotates in the ink-absorption direction, ink is not absorbed if the carriage is in the false-absorption position. Figure 2-13 shows process of conveying motive power to the pump drive roller.

The process of conveying the motive power to the paper eject roller is shown in Figure 2-15. This motive power is conveyed to Gear C through Gear B. The lever that drives Gear C, the carriage lock, and the head-cleaner mechanism is shown separately but it is constructed as one unit. Since the engagement of these parts depends on the tension of the compression spring, if the lever is burdened, only Gear C and the pump roller rotate and no more motive power is conveyed to the lever part.

Operating Principles Printer Mechanism Operation 46