Epson Stylus Photo 925 - Paper Loading Mechanism

EPSON Stylus Photo 925 Revision A
Operating Principles Overview 35
2.1.6 Paper Loading Mechanism
The paper loading mechanism, located in the rear of the printer body, load paper from
the ASF Unit to the PF Roller. This printer employs a stepping motor (ASF/Pump
Motor) dedicated for use with the paper loading mechanism. The driving force from
the ASF/Pump Motor is transmitted to the ASF Unit and the Pump Unit. Table 2-6
below shows the specifications for the ASF/Pump Motor.
The fundamental structure of the paper loading mechanism does not use an ASF HP
sensor but incorporates a single LD roller in the ASF Unit.
The driving force from the ASF/Pump Motor is always transmitted to the ASF Unit.
However, the driving force from the ASF/Pump Motor to be transmitted to the LD
Roller located in the rotating direction of the motor is turned ON/OFF by the Change
Lever and clutch mechanism.
Driving force from the ASF/Pump motor is transmitted to the ASF unit as described
below:
V Switch the ASF/Pump motor drive to ASF unit side
ASF/Pump Motor pinion gear rotates CCW direction with a specific
steps→Combination Gear 14.4, 38.4 (CW)
→Combination Gear 37.6, 44.4 (CCW)
→Change Lever rotates (CCW)
→Release the Clutch mechanism lock position
Figure 2-9 below shows the switching route concerning the driving force from the
ASF/Pump Motor to the ASF Unit.
Figure 2-9. Switch the ASF/Pump Motor Drive to ASF Unit Side
V Transfer the ASF/Pump motor drive to LD roller
ASF/Pump Motor pinion gear rotates CW direction with a specific
steps→Combination Gear 14.4, 38.4 (CCW)
→Combination Gear 37.6, 44.4 (CW)
→Change Lever rotates (CW)→Spur Gear 23.2 (CCW)
→Spur Gear 35.2 (include the clutch mechanism) (CW)
→LD roller (CW)
Figure 2-10 below shows the transmission path of the driving force from the ASF/
Pump Motor to the LD Roller Unit incorporated in the ASF Unit. The LD roller is
mounted on the same shaft on which the spur gear 35.2 is mounted.
Figure 2-10. ASF/Pump Motor Drive Transmission Path
Table 2-6.ASF/Pump Motor Specifications
Item Specifications
Motor type 4-phase 48-pole PM type stepping motor
Drive voltage 42V (DC voltage) +/-5% (voltage applied to the driver)
Coil Resistance 7.0
Ω+/-10% (per phase at 25°C)
Inductance 10.0mH+/-20% (1kH 1Vrms)
Driving method Bi-Polar drive
Driver IC LB1946
Combination Gear
14.4, 38.4
ASF/Pump
Motor Pinion
Change Lever
Combination Gear
37.6, 44.4
Spur Gear 35.2
Spur Gear 23.2
ASF/Pump Motor
Pinion Gear
Change Lever
Combination
Gear
37.6, 44.4
Combination
Gear
14.4, 38.4