Canon fax basic 2000 サービスマニュアル

G3 FACSIMILE COMMUNICATIONS

5–2

1. INTRODUCTION

This chapter describes the fundamental technology and transmission con-

trol procedures relating to G3 facsimile communications.

2. WHAT IS A “G3 FACSIMILE?”

“G3 facsimile” is the general term for facsimiles made in compliance with

 recommendations on an analog telephone line.

In the past, G1 facsimiles and G2 facsimiles were also used. However, G3

facsimiles have become the mainstream because of their good transmission

speed and image quality. G3 facsimiles have the following features:

Features

• Image data is handled as groups of black and white dots.

• Coding and high-speed modulation are adopted.

• Various and diverse functions can be used as binary signals are

adopted for control procedural systems.

When G3 facsimiles first appeared on the market, they transmitted a A4-

size standard document in about one minute. However, the document

transmission time was drastically reduced by improvements made in

MODEMs and coding schemes.

Standard A4 document transmission time: approx. 3 sec

(transmission in standard mode: V.34 MODEM installed facsimiles

excluding control procedures.)