Kyocera Mita FS-6750, Руководство по обслуживанию, Страница: 92 / 161

Operation theory
Logic controller system
4-34 FS-6750
Printing data processing
The printer communicates with the host computer for receiving the print data at
one of the printer’s interfaces and temporarily store them in the interface buffer.
The main logic controller analyzes the data for translating them into the dot data
ac-cording to the original print image. The resultant dot data are depicted in the
raster memory (DRAM’s).
While data processing is in course, on the other hand, the main logic controller
CPU talks to the engine CPU via the engine interface, to discern the readiness of
the printer’s engine for printing.
If the engine is ready to start printing, the main controller issues print signal to-
wards the engine controller which request the paper feed. In synchronization with
the procerssion of the paper within the printer, video data in the raster memory is
released. Thus the video data are transfered to the laser scanner together with the
horizontal synchronization signal and the video clock.
On reception of the video data, the laser diode turns on and off to constitutes the
print image over the drum. The image on the drum, referred to as the static latent
image, is applied with toner, transferred onto the paper, and finally fused perma-
nently on the paper by means of heat and pressure.
System ROM
The system DIMM (YS01) accommodates system codes. The DIMM mounts two
flash ROMs. For firmware upgrade, the system DIMM is detachable for easy
replacement.
Main RAM
The RAM temporarily stores print data and font information transferred from the
host buffers. The size of the RAM is expandable using comprehensive DIMMs.
Table 4. 5 System ROM
Socket No. YS01
Pins 72 (DIMM)
Size 4 Mbyte
Composition 16 Mbit × 2
Access speed <100 ns
Table 4. 6 Main RAM
Number of RAMs 2
Socket Nos. U32, U33
Number of pins 42, TSOP
Size 16 MB (Taiwan)/32 MB (Korea)
Composition 2 MB (1 MB × 16 bits × 2)
Access speed <80 ns