The machine's scanning lamp is a xenon lamp consisting of a tube in which xenon gas is sealed. On the inner side of the glass tube are 2 electrodes running parallel

to the tube axis, while the inner side is coated with fluorescent material. When high-frequency high voltage is applied to the electrodes, the gas inside the tube starts

to discharge, thus illuminating the fluorescent material.

5.3.3.3 Controlling the Activation

iR5065 / iR 5055 / iR5075 / / /

The machine turns on or off the scanning lamp using the drive signal (XE_ON) from the CPU on the reader controller PCB. In response to the signal, the inverter

PCB generates high-frequency high voltage in the activation control circuit using the drive voltage (+24 V) supplied by the reader controller PCB, thus turning on

the xenon lamp.

5.3.4 Detecting the Size of Originals

5.3.4.1 Overview

iR5065 / iR 5055 / iR5075 / / /

The machine identifies the size of an original with reference to the combination of measurements taken of the light reflected at specific points of the CCD and the

output of a reflection type sensor. It takes measurements at 2 points for individual sizes to ensure correct identification even in the event that the original is displaced

while the ADF is being closed.

- for main scanning direction, by the CCD (for AB, 8 points; for inch-configuration, 6 points)

- for sub scanning direction, by a reflection type photosensor (for AB-configuration, 1 point; for inch-configuration, 1 point)

The machine identifies the size of an original as follows:

1) External Light (main scanning direction only)

While keeping the scanning lamp off, the machine measures the CCD level at individual points of measurement in main scanning direction.

2) Sensor Output Level

The machine turns on the scanning lamp, and measures the CCD level at individual points of measurement in main scanning direction. Also, the machine turns

on the LED of the reflection type photosensor in sub scanning direction to measure the sensor output. It uses the combination of the measurement and the output

to identify the size of the original in question.

5.3.4.2 Points of Measurement Used for Original Size Identification

iR5065 / iR 5055 / iR5075 / / /

For main scanning direction, the machine moves the No. 1 mirror base to the point of CCD original detection to measure the CCD level at individual points of

measurement. For sub scanning direction, the machine uses the outputs of original sensors 1 and 3.

AB-Configuration

CCD original detection position

1. Checking the Presence/Absence of an Original at 2 Points (individual points of detection)

For main scanning direction, the machine identifies the presence/absence of an original with reference to the CCD output at 2 points (nearest).

5-8

Inverter PCB

scanning lamp

Activation

control

circuit

LA1