Chapter 2

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2.4.2 Main Controller

2.4.2.1 Main controller components

0017-5107
F-2-26
a) ASIC (IC1/IC2)
The ASIC with a 16-bit internal bus is driven in sync with the 66 MHz external clock. It supports the following
functions:
Image processing unit
This unit converts the RGB multi-value image data or CMYK multi-value data received from the host computer
through the interface connector to the binary image data for the ink colors used.
DMA controller
This controller control DMA transfer of the data transferred through the input interfaces such as the USB and
expansion card slot as well as DMA transfer of the data stored in the DIMM.
Image data generation/output function
This function generates image data for color printing from the received image data and the mask pattern
(corresponding to print mode) stored in the FLASH ROM, and stored the generated image data in DIMM. It also
outputs the generated image data to the carriage PCB.
Interrupt controller
This controller receives and processes internal interrupts and external interrupts from the USB, image
processing unit, and expansion card slot.
Timer function
Even when the printer is turned off, the timer function is held on using the RTC(IC803) and lithium
battery(BAT801) to assist the cleaning function.
When the power cord is plugged to the outlet, power is supplied to the RTC and therefore the lithium battery
power is not consumed.
Heat Enable signal control function
This function uses the pulse width to perform variable control of the time of application of the Heat Enable
signal to the nozzle heater board for each printhead nozzle array.
Linear scale count function
This function reads the linear scale when the carriage moves, thus generating the ink discharge timing. It also
counts the linear scale timing cycle using the reference clock to measure the carriage moving speed.
Dot count function
This function controls the discharge dots used as the information for Heat Enable signal control, maintenance
jet control, cleaning control, and remaining ink level for each nozzle array.
IC3100
IC604
IC2900
IC2802IC1201
IC802IC803IC302
IC603
IC601
IC602
IC301
IC2IC1 IC701BAT801
IC2902