EPSON Stylus Color 900 Revision C
Operating Principles Printer Mechanism Operating Principles 47
Table 2-4. Linear Encoder Specifications
The ASIC (IC2) reads the linear scale (increment: 1/180 inch) and
internally divides data by 8. The read information is used to produce
basic drive frequency for 2880-dpi trapezoidal waveform production.
If the encoder is defective or in an undetectable condition, the printer
generates a fatal error immediately after power on. This error occurs
before the carriage’s home position seeking operation.
Beside detecting the carriage position, the CRHP sensor also serves to
determine whether or not the carriage is working properly. If the setting
signals (pulses) sent from the encoder do not reach the specified level
while the CR is moving in the acceleration / constant / deceleration
modes in its operative range, the program consequently assumes that
paper is jamming or the carriage is operating irregularly, and shows the
paper jam error by bringing up the LEDs of the corresponding
combination.
The printer is equipped with 2 actuators used to detect the ink
cartridges in the carriage unit driven by the CR motor. The printer,
however, is designed to operate the actuators only when both black
and color ink cartridges are installed. See Table 2-5 and Table 2-6 for
the ink cartridge sensor specifications and ink cartridge sensor switch
mode, respectively.
Table 2-5. Ink Cartridge Sensor Specifications
Table 2-6. Ink Cartridge Sensor Switch Mode
If the ink cartridge sensor is defective or in an endetectable condition,
the printer shows No Ink Cartridge Error immediately after the printer is
turned on.
No.
Item Specifications
1 Type Radiative Incremental encoder module
2 Drive voltage 5 VDC
±
5%
3
Output
waveform
Phase A/B 2-channel digital output (TTL level)
4 Minimum step 1/180 inch (increment of the lines on the linear scale)
5
Response
frequency
20 KHz
No.
Item Specifications
1
Detection type
Using a micro switch
2
Rated voltage
5 VDC
±
5%
3 Rated current 10 mA
4 Contact resistance 50 m
Ω
Cartridge
Sensor Status Sensor Output
Absent Open 2.4 VDC or more
Present Closed 0.7 VDC or more
