Epson Stylus Photo 925, Service Manual

Page: 34 / 167

EPSON Stylus Photo 925 Revision A
Operating Principles Overview 34
2.1.5 Cutter Mechanism
This printer is equipped with a cutter mechanism to cut the ejected paper automatically
after printing on roll paper. The cutter consists of a combination of the fixed cutting
edge and movable rotary blade. The cutter mechanism consists of the Cutter Motor,
Cutter Unit (movable rotary blade and fixed cutting edge), Timing Belt, Paper Eject
Roller, Star Wheel Roller, etc.
2.1.5.1 Cutter Motor
Like the motor for the paper feed mechanism, a DC motor is employed as the Cutter
Motor. Table 2-5 below shows the specifications for the Cutter Motor.
The driving force from the Cutter Motor is transmitted via gears to the timing belt so
that the movable rotary blade mounted on the fixed cutter rotates along the fixed
cutting edge to cut the paper. Like the CR Motor and PF Motor, the Cutter Motor is a
DC motor. However, cutting operation is not controlled by a scale and encoder but is
controlled by the two photosensors mounted at both ends of the moving area of the
movable rotary blade. Figure 2-8 shows the transmission path of the driving force from
the Cutter Motor and the names of parts on the path.
Figure 2-8. Cutter Mechanism
Table 2-5.Specifications for Cutter Motor
Items Specifications
Motor type DC motor with brush
Drive voltage 42VÅ}5% (voltage applied to the driver)
Armature resistance 48.4
Ω±
25%
Inductance 20.3mH
±
}25%
Drive method
Turns ON and OFF at two values of a maximum of 0.8 A for
normal run and a maximum of 1.2 A for reverse run
Driver IC LB1947
Cutter Motor
CT Sensor (Home-80)
CT Sensor (Home-0)
Movable Rotary Blade
Timing Belt
Paper Eject Roller
Fixed Cutting
Edge
Cutter Motor
Pinion
Timing Belt