Toshiba DP120F Service Manual page 321

(1) The CIS detects the LED array's light reflected by a document as an analog electric
signal and sends it to the DSC (IC59).
(2) The DSC converts the electric signal to a digital signal and subjects it to data correction,
then converts it to raster data. The raster data is serially transferred to the DSC interface
of the PTC GA (IC45).
(3) The raster data is converted from serial to parallel data by the DSC interface of the PTC
GA and transferred to the PIX-DRAM (IC25). During this period, the system communi-
cates with the destination to identify the coding for the data to be transmitted.
For memory transmission, go to step (4).
For direct transmission, go to step (6).
(4) The raster data is transferred to the CODEC (IC51) through the CODEC interface of the
PTC GA where it is coded to data in the JBIG format. Then the JBIG coded data is
transferred to the SYS-DRAM (DP120F: IC34, IC41/DP125F: IC46). This allows the
coded data for all the documents for transmission to be stored in the SYS-DRAM.
(5) The JBIG coded data is transferred to the CODEC where it is decoded to raster data.
Then the raster data is transferred to the PIX-DRAM.
(6) The raster data is transferred to the CODEC where it is coded in accord with the coding
format (MH, MR, MMR or JBIG) specified by the destination. Then the coded data is
transferred to the SYS-DRAM. This allows one page of coded data to be stored in the
SYS-DRAM.
(7) The coded data is transferred to the MODEM (IC5) where it is modulated to an analog
signal for telephone lines. Then the modulated analog signal is sent to the telephone line
through the NCU PBA.
DP120F/DP125F Circuit Description 7-12 March 2000 © TOSHIBA TEC