EPSON Stylus Color 900 Revision C
Operating Principles Printer Mechanism Operating Principles 46
2.2.1 Carriage Mechanism
As shown in Figure 2-1, the carriage unit with the printhead on it moves
right and left, depending on the rotational direction of the CR (Carriage)
motor. Table 2-1 shows the CR motor specifications.
Table 2-1. CR Motor Specifications
The CR unit position is always memorized and controlled by the CRHP
(Carriage Home Position) sensor. This sensor confirms the CR position
to renew the memory at the following timing:
When power is turned on / off
When a head cleaning operation, including initial ink charge, is
performed.
When the printer returns to a ready status because the printer
has executed print job or receives no data for one second or
more.
See Table 2-2 and Table 2-3 which show the CRHP sensor
specifications and CRHP sensor switch mode, respectively.
Table 2-2. CRHP Sensor Specifications
Table 2-3. CRHP Sensor Switch Mode
If this sensor is defective or does not work, it does not detect the
carriage while the carriage is in the home position seek mode. In this
case, the printer cuts off electricity to the CR motor and shows a fatal
error.
Like the Stylus Pro5000, the Stylus color 900 also uses a linear encoder
to obtain secure carriage movement and accurate print timing. The
linear encoder reads slits on the encoder belt (linear scale) above the
timing belt to control the carriage. See Table 2-4 for the linear encoder
specifications.
No. Item Specifications
1 Motor Type 4-phase / 200-pole / HB-type stepping motor
2 Drive voltage 42 VDC
±
5% (Applied to the driver)
3 Coil resistance 5.8
Ω
±
10%
4 Drive mode Bipolar constant current drive
No. Item Specifications
1Type
Photoelectrical transfer system
(SHARP GP1S73P2)
2 Drive voltage 5 V
±
5%
3 Collector resistance
30 VDC or less
CR Position Switch mode Sensor output
Within the CRHP
range
Open 0.7 VDC or less
Off the CRHP range Close 2.4 VDC or more
