Okioffice87 - Oki OKIFAX4550 Maintenance Manual

2.2

OKIOFFICE87

(1) Copy Mode
Figure A.5 (1/13) shows the picture signal route in local copy mode
One-line picture data is transferred to operational amplifier from the scanning unit (CIS: contact
image sensor) as an analog data. The picture data is sent to LC821033 (image processing LSI).
Here, the picture data undergoes various kinds of picture processings (LC821033), converted
to two-level binary data (black and white) and then sent to IOGA6 (scanning control). The one-
line binary picture data from IOGA6 is stored into DRAM. When the data for one page has been
stored in the DRAM, the data is read out from the DRAM and sent to IOGA6. The data is
converted into a serial data by the picture control of IOGA6 and transferred to the LED print head
for printing as HDATA3~0. Writing of data into the page memory is also possible during the
printing operation.
(2) G3 Send Mode
Figure A.5 (2/13) shows the G3 send picture signal route
In the G3 mode, the data transfer route from the scan unit up to the DRAM is the same as in the
copy mode described in (1).
The picture data for one-line is transferred from DRAM to CPU. The CPU performs the picture
data processing (encode) for this picture data (FILLER, fill bits are inserted etc.) and again stores
into the DRAM. The stored encoded data is output from DRAM to the MODEM under the control
of CPU. After modulation, the picture signal "S" is sent to the NCU board as the transmission
data. The transmission data "S" goes through the amplifier and is sent to the telephone line L1
and L2 via the transformer T1 as high speed signal.
(3) G3 Receive Mode
Figure A.5 (3/13) shows the G3 receive picture signal route
In the G3 mode, the high-speed picture signal arriving from the telephone line at L1 and L2 of
NCU passes through the transformer T1 and the amplifier and is input to the MODEM as "R"
signal. After demodulation by modem, the picture data is sent to CPU. The CPU performs the
picture data processing (decode) for this picture data and stores into the DRAM. Then, the stored
picture data is again written into DRAM (as a page memory) by the picture processing control
of IOGA6. When the data for one page has been stored in the DRAM, the data is read out from
the DRAM and sent to IOGA6. The picture data is converted into a signal data by the printer
control of IOGA6 and transferred to the LED print head for printing as HDATA3~0.
(4) PC Print
Figure A.5 (4/13) shows the signal route in PC Print mode.
The data input from the R46's parallel I/F is input, through the LVC161284 and IOGA6, to the
DRAM using DMA.
The input data is transferred to the Decoding block in the IOGA6 using DMA.
In the Decoding block, the data is expanded in the 1-line raster buffer in the IOGA6. Then, the
expanded data is sent to the video block in the IOGA6 in response to a 1-line synchronous signal.
In the video block, image processing is performed for printing and the resultant data is transferred
to the LED head.
(5) PC Scanner
Figure A.5 (5/13) shows the signal route in PC Scanner mode.
The data transfer route from the scan unit up to the DRAM is the same as in the copy mode
described in (1).
The data input to the IOGA6 is temporarily written into the external DRAM (4 megawords x 16
bits). The written data is compressed to TIF data by firmware, then written into the external
DRAM again.
The written TIF data is sent to the R46's parallel I/F through the LVC161284 and IOGA6.
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