Panasonic KX-FP342BX, Service Manual

Page: 127 / 217

7.4. FACSIMILE SECTION
7.4.1. IMAGE DATA FLOW DURING FACSIMILE OPERATION
Copy (Fine, Super-Fine, Half Tone)
1. Line information is read by CIS (to be used as the reference white level) via route1, and is input to IC501. Refer to BLOCK
DIAGRAM(P.128)
2. In IC501, the data is adjusted to a suitable level for A/D conversion in the Analog Signal Processing Section, and via route2
it is input to A/D conversion (8 bit). After finishing A/D conversion, the data is input to the Image Processing Section via
route3. Then via route4 and route5, it is stored in RAM as shading data.
3. The draft’s information that is read by CIS is input to IC501 via route1. After it is adjusted to a suitable level for A/D
conversion via route2, 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 route6 and route7, 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 routes4
and 5, they are stored in RAM.
4. The white/black data stored as above via routes6 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 route9 and is printed out on recording paper.
Note:
Standard: Reads 3.85 times/mm
Fine: Reads 7.7 times/mm
Super-Fine: Reads 15.4 times/mm
Transmission
1. Same processing as Copy items 1 - 3.
2. The data stored in the RAM of IC501 is output from IC501 via routes6 and 10, and is stored in the system bus.
Via route11, it is stored in the communication buffer inside DRAM (IC503).
3. While retreiving data stored in the communication buffer synchronous with the modem, the CPU (inside IC501) inputs the
data to the modem along route12, where it is converted to serial analog data and forwarded over the telephone lines via the
NCU Section.
Reception
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 (IC501) stores the data in the communication buffer DRAM (IC503)
along route12.
2. The data stored in DRAM (IC503) is decoded by the CPU (IC501) via route12, and is stored in DRAM (IC503) via routes13
and 5.
3. Same processing as Copy item 4.
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KX-FP342BX