Epson Stylus Photo 925 - Carriage Home Position Detection; Platen Gap Adjustment Mechanism & Parallelism Adjustment Mechanism

EPSON Stylus Photo 925 Revision A
Operating Principles Overview 32
Figure 2-5. Carriage Mechanism
2.1.3.2 Carriage Home Position Detection
This printer detects the carriage home position by the speed and position signal
generated by the CR motor drive current and linear encoder. (For the CR motor
control circuit, see 2.2.2.2 "Motor Driver Circuit".)
2.1.3.3 Platen Gap Adjustment Mechanism & Parallelism
Adjustment Mechanism
The adjust lever (PG Lever) is mounted on the right end of the carriage guide shaft.
The carriage guide shaft is an eccentric shaft and is rotated by operating the adjust
lever, and thus narrows (1.2 mm) or widens (2.1 mm) the gap (platen gap; PG) between
the platen surface and the print head.
Figure 2-6. Adjustment of Adjust Lever
CR Motor
Parallelism Adjustment
Bushing
Linear Scale
CR Unit
Adjust Lever (PG
Lever)
CR Guide Shaft
Photo-interrupter
(Encoder)
Platen Surface (Paper
Guide Inside Front)
Table 2-3.Adjust Lever Setting
Lever Setting Position Amount of PG Correction
Front position 0 mm (PG:1.2 mm)
Rear position +0.9 mm (PG:2.1 mm)
Parallelism
Adjustment Bushing
Adjust Lever
Carriage Guide Shaft (Eccentric Shaft)
Front Side
Deep Side