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1. Line information is read by CIS (to be used as the reference white level) via route (1), and is input to IC1. Refer to Block Dia-

gram (P.22)

2. In IC1, the data is adjusted to a suitable level for A/D conversion in the Analog Signal Processing Section, and via route (2) it

is input to A/D conversion (8 bit). After finishing A/D conversion, the data is input to the Image Processing Section via route
(3). Then via route (4) and route (5), it is stored in RAM as shading data.

3. The draft’s information that is read by CIS is input to IC1 via route (1). After it is adjusted to a suitable level for A/D conversion

via route (2), the draft’s information is converted to A/D (8 bit), and it is input to the Image Processing Section. The other side,
the shading data which flows from RAM via route (6) and route (7), is input to the Image Processing Section. After finishing
the draft’s information image processing, white is regarded as "0" and black is regarded as "1". Then via routes (4) and (5),
they are stored in RAM.

4. The white/black data stored as above via routes (6) and (8) is input to the P/S converter. The white/black data converted to

serial data in the P/S converter is input to the Thermal Head via route (9) and is printed out on recording paper.
Note:

Fine: Reads 3.85 lines/mm 
Super Fine: Reads 7.7 lines/mm
Photo: Reads 15.4 lines/mm

1. Same processing as Copy items 1 - 3.
2. The data stored in the RAM of IC1 is output from IC1 via routes (6) and (10), and is stored in the system bus. 

Via route (11), it is stored in the communication buffer inside DRAM (IC4).

3. While retrieving data stored in the communication buffer synchronous with the modem, the CPU (inside IC1) inputs the data to

the modem along route (12), where it is converted to serial analogue data and forwarded over the telephone lines  via  the
NCU Section.

1. The serial analog image data is received over the telephone lines and input to the modem via the NCU section, where it is

demodulated to parallel digital data. Then the CPU (IC1) stores the data in the communication buffer DRAM (IC4) along route
(11).

2. The data stored in DRAM (IC4) is decoded by the CPU (IC1) via route (12), and is stored in RAM via routes (13) and (5).
3. Same processing as Copy item 4.

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1. Function

This unit utilizes state of the art thermal printer technology.
The recording paper (roll paper) is chemically processed. When the thermal head contacts this paper it emits heat momen-
tarily, and black dots (appearing like points) are printed on the paper. If this continues, letters and/or diagrams appear, and the
original document is reproduced.

2. Circuit Operation 

There are 27 driver ICs aligned horizontally on the thermal head and each one of these ICs can drive 64 heat emitting regis-
ters. This means that one line is at a density of 64

×27=1728 dots=(8 dots/mm).

White/Black (white=0, black=1) data in one line increments is synchronized at IC1 pin 117 (THCLK), and sent from IC1 pin 116
(THDAT) to the shift register of the ICs. The shift registers of the 27 ICs are connected in series, and upon the shift of dot
increment 1728, all the shift registers become filled with data, and a latch pulse is emitted to each IC from IC1 pin 118
(THLAT).With this latch pulse, all the contents of the shift registers are latched to the latch registers. Thereafter, through the
addition of strobes from the IC1 pins (103 - 104) only black dot locations (=1) among latched data activates the driver, and the
current passes to heat the emitting body causing heat emission. 
Here, the two line strobes, STB1 and STB2, impress at intervals of 9.216 msec, as required for one-line printout.
The sequence is shown on the next page. [Moreover, for the strobe width, the thermistor value inside the thermal head is 
detected according to IC1 pin 4. Depending on that value, the strobe width is recorded in FLASH (IC2). 
Accordingly, the strobe width is determined.
When the thermal head is not used, the IC1 (17, HEADON) becomes low, Q6 turns OFF, Q7 turns OFF, and the +24 V power
supply for the thermal head driver is not impressed to protect the IC.

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