Epson Stylus PHOTO 950 Service Manual page 41

EPSON Stylus PHOTO 950
Step 5 : How to Operate Paper Return Lever
Following is the operation principles mentioned how to operate paper return lever.
12. Once you remove the "silence gear", you can see the "cam gear" which has a role
for pushing down the "paper return transmission lever.
13. This "cam lever" is always jointed with both the "silence gear" and "super gear
28.8" (for driving LD roller on ASF).
14. When the "silence cam" rotates to counter clockwise, the "cam gear" will rotate to
clockwise. And a part of circle arc (cam) on the "cam gear" pushes down the
"paper return transmission lever". And paper return lever will be laid to guide a top
paper to the printer internal.
C H E C K
There are two alignments on the right side of the ASF to get a
P O I N T
correct timing for driving paper load operation and ASF reset
operation.
Paper return transmission lever
Cam gear
Figure 2-23. Silence Cam mechanism (9)
OPERATING PRINCIPLES
Paper return
lever shaft
A part of circle arc of
the "Silence cam"
Printer Mechanism
2.2.4.1 Pump Mechanism
The pump mechanism draws up ink from the printhead and from the cap assembly. In
addition, there is also a head cleaning wiper located inside the cap assembly. An
outline of the operation of the pump mechanism is given below.
The drive force for the pump mechanism is provided by a 4-phase 48-pole PM-type
stepping motor which is used as the pump motor. The specifications for this pump
motor are given below.
Table 2-5. Pump motor Specifications
Item
Type
Drive Method Bipolar 2-2 phase, 1-2 constant current drive
Drive Voltage
Coil Resistance
Inductance
The Pump unit and Wiper mechanism drives according to the Pump motor rotational
direction, as shown in the following table.
Table 2-6. Pump unit functions
Pump motor
(*1)
rotational directions
Clockwise
Counterclockwise
NOTE: (*1) Pump operating direction : CW refers to clockwise operation when
Revision A
Description
4-phase 48-pole PM-type Stepping Motor
+42V +/- 5% (DRV IC voltage)
10Ω +/- 10% (per phase at 25 degree)
10.5mH +/- 20% (1kH 1Vrms)
Pump unit functions
• Absorbs ink by the pump unit
• Sets the wiper
• Release ink by the pump unit
• Resets the wiper
looking from the motor output shaft.
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