Canon fax basic 2000 서비스 매뉴얼

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G3 FACSIMILE COMMUNICATIONS

3. G3 FACSIMILE IMAGE TRANSMISSION

The following shows a block diagram of G3 facsimile image transmission.

Fig. 5-1   Image Transmission by G3 Facsimile

Description of each block

(1) The document is converted to electrical signals by the contact sensor.

(2) After the document is converted, the electrical signals undergo A/D

conversion to be converted to digital binary image data.

(3) The binary image data is compressed by coding to reduce the size of

the data to be sent as much as possible. The resulting data is coded

data.

(4) The coded data is converted to analog signals modulated by the

MODEM, and is transmitted via the telephone line.

(5) The modulated analog signals are demodulated by the MODEM on the

receiving side. The resulting data is digital coded data.

(6) The coded data is converted to binary image data by decoding.

(7) The binary image data is sent to the recording section to be printed.

This chapter describes (3) through (6).

(1) and (2) are described in Chapter 3, Reading Section, and (7) is

described in Chapter 4, Recording Section.

3.1

Structure of Image Signals

Reading of the image is performed in each scanline in the 

 direction. The horizontal scanning line density is 8 dots/mm or 16

dots/mm. After one line is read, the next line is read at the pitch of the 

 line density. There are three vertical scanning line densities:

3.85 lines/mm (standard mode), 7.7 lines/mm (fine mode) and 15.4 lines/

mm (super-fine mode). Reading is also possible at 16 dots/mm 

×

 15.4

Transmitting
side

Document

(1)
Contact
sensor

(2)
A/D
conversion

(3)
Coding

(4)
Modulation

To the line

Receiving
side

From the line

(5)
Demodu-
lation

(6)
Decoding

(7)
Recording
section

Received
image