Chapter 22-13F-2-12e) Printhead maintenance unitThe printer performs cleaning operations of the printhead at the carriage homeposition.In the wiping operation, the printhead installed in the carriage are wiped as the purge motor rotates when the carriage is stopped at the carriagehomeposition. The maintenance jets are the carriage passes through the maintenance jet tray, located on the right side of the platen, while the carriage ismoving forward. The suction operation is performed using the suction cap of the purge unit.f) Gap adjustment unitThe printhead height adjustment lever located on the right side of the carriage works in coordination with the height adjustment cam. The height adjustmentrollers located at the bottom-right edge of the carriage front are moved up and down by this mechanism, and this moves the head holder position up ordown to change the gap between the face of the printhead and the media.g) Registration sensor unitThe resistration sensor at left bottom of the carriage consists of two LEDs and receiver sensor.h) Rail cleaner unitThe rail cleaner at far right of the carriage is used to prevent contamination of the rail.i) Internal temperature detectionA thermistor for measuring the internal temperature is installed on the head relay PCB on the rear of the head holder.2.3.2.4 Printhead2.3.2.4.1 Structure of printhead0008-6344A printhead has six nozzle arrays. Each nozzle can be controlled individually so that a six-color discharge action is performed by a single printhead.a) Nozzle arraysEach nozzle array provides 1280 nozzles arranged in a two-column staggered pattern. Each column is comprised of 640 nozzles separated by an intervalof 1/600inch and is arranged in a staggered pattern to form 1280 nozzles separated by an interval of 1/1200 inch.Carriage relay PCBHead relay PCBCarriage coversensorRegistrationsensor Printhead heightadjustment leverSensor FlagCarriage HP / headheight sensorMaintenance-jet tray