Epson Perfection 4870 Photo, Service Manual

Page: 20 / 87

Perfection 4870 Photo Revision A
OPERATING PRINCIPLES Engine Operation Outline 20
2.1 Engine Operation Outline
This section explains the functions and operating principles of the Perfection 4870
Photo Engine. The Engine is roughly divided into the Carriage Unit and Carriage
Moving Mechanism.
2.1.1 Outline
2.1.1.1 Carriage Unit outline
The Carriage Unit consists of the CCD Board, Inverter Board, Lamps (light source),
Mirror/Lens Mechanism, Glass Plate, and Solenoid.
(Refer to figure 2-1, and 2-2.)
Figure 2-1. Carriage Unit Configuration
†
CCD Board Forms an alternative six-lines color CCD (R, G, B
independent) and its control and drive circuits.
†
Inverter Board 24VDC and converts DC to AC to generate
the voltage for driving the Lamps (white cool cathode
fluorescent lamps).
†
Lamps White cool cathode fluorescent lamps are used as a
light source. When the amount of light is not stable, the
Panel LED is flashes and enter the standby mode until
it becomes stable.
†
Mirror/Lens Mechanism The beam applied to the scanned document is reflected,
passes through the Mirror/Lens Mechanism in the
Carriage Unit for correction of the beam axis, and then
reaches the CCD Sensor. The light components R, G, B
are extracted by the Color CCD Sensor itself, not by
switching between R, G and B of the light source as
previously.
†
Glass Plate Adjusts the difference of wavelength between the
infrared light and visible light when the Digital Ice
function is used.
†
Solenoid Used to operate the Glass Plate.
Figure 2-2. Mirror/Lens Mechanism
Lamps
Inverter Board
Front
Rear
CCD Board
CCD Sensor
Mirror 2
Mirror 4
Mirror 5
Lens Mirror 1
Glass Plate
Solenoid CCD Sensor
CCD Board Lamp Lamp Mirror 3
Document
Scanned image
Front Rear