New System Solutions for Laser
Printer Applications
By Oreste Emanuele Zagano
STMicroelectronics
INTRODUCTION
Recently, the laser printer market has started to move
away from custom OEM-designed formatter boards, where the
brand manufacturer designs the complete system and outsources
the mass production. Replacing this is an ODM approach,
where external companies take charge of the entire system,
including the design.
This trend began first in the low-end models, like host-based
multifunction printers, but in the near future it will extend
to the mid- and high-end models also, moving most of the
system-level design from the brand manufacturer to external
third parties, with expertise in specific areas.
This opens the market to companies with strong competence
in ASICs and other areas needed to master the whole process
and to offer a complete system solutions for laser printer
brand manufacturers such as firmware, image processing,
software, board design, test and qualification,.
With a single external company undertaking the entire system
design, the printer brand manufacturer is able to reduce
the number of suppliers and take advantage of a tight synergy
among different areas that consequently results in a shorter
development time to launch new products on the market.
In order to be ready to provide best-in-class solutions,
chip-design companies must establish strong partnerships
with external companies with complementary skills, creating
a team capable of producing a full working prototype of
a formatter board, aimed at demonstrating the accumulated
system level expertise.
System description
In our lab, the initial goal was to replace the existing
formatter board inside a laser printer bought on the market
with a new one, entirely designed with a customized mass-market
chip in order to achieve a higher level of integration and
to reduce the overall cost of the BOM of the final board.
Fig. 2 - Lab test bench and equipment
The reference printers were two low-end host based single
function printer models:
· A monochrome printer with 600 x 660 dpi resolution,
20 ppm , A4 paper format, costing less than $200
· A color printer with 600 x 600 dpi resolution,
A4 paper format, costing around $450
We used the overall plastic chassis, the mechanics, and
the complete laser engine of the two reference printers,
in conjunction with the new formatter board, simply moving
the flat cable of the original formatter.
Fig. 3 - Color (top) and B&W (bottom) formatter board
replacement with our solution
The prototype is based on a development board that includes
an ARM9EJ-S® microprocessor, the standard and connectivity
peripherals (DDR2 memory, USB 2.0 host and device, Ethernet
IF, serial NOR Flash), and a Virtex 5 Xilinx® FPGA,
used to implement the specific blocks needed to manage the
serial interface and the laser engine controller.
The development board can be easily controlled by a run-time
debugger on a PC, connected with a hyperterminal serial
interface and supporting a JTAG debugger to allow firmware
development.
An adapter board was designed to connect the development
board with the specific connectors required by black and
white and color laser engines chosen for the test. The adapter
fits these two models widespread on the market, but it can
be easily modified to be compliant with other models, on
customer demand.
Hardware
The core of the system is a SPEAr600 device that provides
the main architecture built around the ARM9EJ-S® microprocessor
and a set of standard peripherals connected with an AMBA
bus. The following are the main features of the device:
Dual ARM926 (DC 16KB, IC-16KB) running up to 333 MHz
Memory controllers
DDR1/DDR2 controller
Serial Flash controller
Parallel NAND controller
Connectivity
USB 2.0 device
2 x USB 2.0 hosts
Ethernet 10/100/1000
UARTs, I2C, SPIs, IrDA
Customizable logic: 600 Kgates + 128 KByte of SRAM memory
Boot ROM: 32 KB
Color LCD controller
JPEG codec
Spread spectrum clock
ADC: 10-bit, 8 channels, 1 Ms/s
8 channels, general purpose DMA
Real time clock, timers
Multi-layer interconnect matrix
To read this full article
in PDF click this link to download
