Epson Scan 2500 service manual Scanner Principles, Carriage Unit

EPSON Stylus Scan 2500 Revision A

2.3 Scanner Principles

This section explains the operating principles of the scanner mechanism. The scanner mechanism can be divided into the Carriage Unit and Carriage Operation.

2.3.1 Carriage Unit

The Carriage Unit is mainly composed of the CCD sensor board, inverter board, lamp (light source), mirror, and lens. (See Figure 2-18and Figure 2-19.)

Figure 2-18. Carriage Unit Component

CCD Sensor Board:	This board controls the Color CCD line sensor
	(independent R,G,B) and drive circuit.When power
	is turned on and the LCD display shows "Warm up",
	the CCD sensor board is actually performing a
	standard white test.

Inverter Board:	This board provides voltage to drive the lamp.
Lamp:	A white cold fluorescent lamp is used as the light
	source.
Mirror and Lens:	The light emitted to the document reaches the CCD
	sensor after being reflected on some mirrors one after
	another. Instead of changing the light source to
	create R/G/B light component as many previous
	models did, the color CCD itself creates each R/G/B
	light component.

Figure 2-19. Mirror, Lens Mechanism

Operating Principles Scanner Principles 50