FUJITSU C150-E049-02EN - Manual (Page 26)

M3099GX/GH OEM Manual 1-9
OVERVIEW
Main control unit
This scanner is controlled by a 80C186 MPU. This scanner consists
of a ROM as a program area, internal registers, an external RAM as a
work area, gate arrays for the MPU peripheral and video circuits,
dither processing and
γ
conversion RAMs, and error diffusion.
Interface control
SCSI-2 interface
SCSI (small computer system interface) circuit consists of SPC
(MB86601A), VCEP (OTI95C71/20) and a glue ASIC. The scanned
image data are transferred to interface circuit as video interface. The
interface circuit converts internal video interface to SCSI interface via
compression, if required. SCSI interface transferes data 1.5MB/s in
Asynchronous transfer, 4.0MB/s in Synchronous transfer following to
SCSI-2 standard. The VCEP compresses the binary image data in
MH, MR, MMR algorithm defined by CCITT G3, G4. See Chapter
3 for details of SCSI interface.
Resolution
The basic resolution of this scanner is 200dpi. The resolution can be
changed to 240, 300, or 400dpi from the host computer or the
operator panel.
The resolution in the subscanning direction is achieved by changing
the document transport speed.
When the image processing circuit II (IPC II) option is installed, the
linear density is changed by setting the parameter to its internal circuit.
Video amplifier and driver section
This section consists of a CCD drive circuit, a video amplifier circuit,
a white-black level correction circuit, sensors, and also control circuits
for the stepping motor, heater, and lamps.
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