Converters; Swath Holding Area; Swath Manager; Print Engine Controller - HP DesignJet 200 Service Manual

Converters

The vector to raster converter (VRC) or raster to raster converter (RRC), depending on the
data format sent, rasterizes the data from the display list, swath by swath, and sends the
swaths to a swath holding area.

Swath Holding Area

The swath holding area is part of the DRAM that is specially allocated for this purpose. The
swath holding area is large enough to hold up to three swaths at a time.

Swath Manager

The swath manager firmware algorithm removes data from the swath holding area and
reorganizes the data for more efficient plotting. This enables the plotter to sweep the
carriage to areas that require ink and to conserve motion by not sweeping blank areas of the
media. Variables are calculated and stored during this optimization.
The swath manager then replaces the data into the swath holding area.

Print Engine Controller

The print engine controller removes the organized data from the swath holding area and
copies it to the physical swath RAM area. The plotter's microprocessor has a feature called
burst mode," enabling data to be copied from one area of memory to another very quickly.
The print engine controller uses the variables calculated by the swath manager to determine
the stop and start positions of the swath and thus control the carriage movement.

Swath RAM

The swath RAM is dedicated RAM memory and not part of the DRAM.

Cartridge Interface ASIC

The cartridge interface ASIC (Application Specific Integrated Circuit) controls the shuffling
of pure swath data to the actual firing order of the cartridge nozzles. It fetches pixels from
the physical swath RAM and sends it serially through the trailing cable to the carriage ASIC.
This sending of pixel data is initiated by means of a signal sent to the cartridge interface
ASIC by the processor support ASIC, so as to synchronize the motion of the media motor and
carriage motor with the firing of the print head drivers.

Carriage ASIC and Cartridge Drivers

The carriage ASIC generates the select and enable signals to drive the cartridge driver
integrated circuits.
The cartridge drivers provide the firing pulses for the print head nozzles.
5 20 Functional Overview
C3187 90000