March 2000 © TOSHIBA TEC 7-17 DP120F/DP125F Circuit Description(1) The CIS detects the LED array’s light reflected by a document as an analog electricsignal 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 interfaceof the PTC GA (IC45).(3) The raster data is converted from serial to parallel data by the DSC interface of the PTCGA and transferred to the PIX-DRAM (IC25). During this period, the system communi-cates with the PC to identify the coding for the data to be transmitted.(4) The raster data is transferred to the CODEC (IC51) through the CODEC interface of thePTC GA where it is coded to data in the JBIG format. Then the JBIG coded data istransferred to the SYS-DRAM (DP120F: IC34, IC41/DP125F: IC46). This allows thecoded data for all the documents scanned 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 the MH coding format.Then the MH coded data is transferred to the PIX-DRAM.(7) The MH coded data is transferred to the PC interface of the PTC GA and sent to the PCthrough the PC I/F PBA.
