EPSON Stylus Color 900 Revision C
Operating Principles Printer Mechanism Operating Principles 50
After a paper loading motion is completed, the semicircular roller rotates
in the normal direction to load the top paper in the stack. This operation
is enabled by the correct phase of the gears in the ASF, because the
timings for the semicircular roller’s contacting the paper surface by the
corner (A) and the hopper’s being pushed out must be coincided. The
ASF sensor is used to determine the condition whether the phase is
correct or not. The transmission system of the ASF sensor detects the
condition by catching the position of the cam attached onto the same
shaft as the semicircular roller is. See Table 2-8 and Table 2-9 for the
ASF sensor specifications and its switch mode, respectively.
Figure 2-4. ASF Paper Load Mechanism
Table 2-8. ASF Sensor Specifications
Table 2-9. ASF Sensor Switch Mode
Note that torque from the pump/ASF motor is transmitted to the pump
unit depending on the pump/ASF mechanism condition. The rotational
directions and corresponding functions are as shown in Table 2-10.
Table 2-10. ASF/Pump Motor Functions
Semicircular
ro lle r
Cam
Pinch roller
H opper
R e tu rn le v e r
Separation pad
[Ready status]
Active Status
1)
2)
3)
4)
A
No.
Item Specifications
1Type
Photoelectric transfer system (transmission
type)
2 Collector voltage 30 VDC or less
3 Coil resistance 5 VDC
±
5%
ASF Position Sensor Status Sensor Output
Home position Open 0.7 VDC or less
Off the home
position
Close 2.4 VDC or more
Direction Functions for ASF
Functions for the ink
system
Normal rotation
(CW)
• Reverse rotation of the
paper loading roller
(paper return control)
• Connection to the pump
gear train
• Normal rotation of the
pump (absorption)
• Releases the CR lock.
• Sets the wiper.
Reverse rotation
(CCW)
• Connection to the ASF
gear train
• Normal rotation of the
loading roller (paper
separation, paper
loading)
• Reverse rotation of the
pump motor
• Locks the CR.
• Resets the wiper.
