Original Reading Control To read text and image of original using the CIS

Original Reading Control

To read text and image of original using the CIS

Original Reading Control

a.Overview

This control is to read out text and image on an original.

The contact image sensor (CIS) reads an original on an image line basis.

The CIS is a sensor that the original exposure LED and the original reading CCD are unified, which enables the reader unit to be downsized.

The principle of image reading by the CIS is as follows:

1)The LED lights up.

2)The light of the LED passes through the light guides to irradiate a original.

3)The irradiated light is then reflected by the document, and comes into the rod lens array.

4)The incoming light passes through the rod lens array, and is received by the CCD array.

5)The CCD array converts the received light into the electrical signal (optoelectronic conversion), and the signal is sent to the reader controller.

Schematic diagram of the CIS is shown below.

Component	Role
LED	A source of light irradiating original
Light Guides	To support the LED light irradiating the whole of 1 image line
Rod lens array	To collect the light reflected by original
CCD array	To receive the reflected light passed through the rod lens array

The CCD array consists of 8 pieces of the 936-pixel channel (per unit). Each channel has the output correction table, and outputs the corrected image signal (gain correction) based on the input illuminance signal.