HP 1050c Service Manual - Page 295

Functional Overview At the ink collector there are two metallic pins between which the resistance is checked. When there is no leakage, there will be air present and the resistance measured will be high. In case of leakage, the collector will contain ink and there will be a potential short circuit between both electrodes through the ink, and the ink leak will detected. The LDS measures the resistance in the collector: if this resistance is below the threshold value, then the system will assume there is ink in the collector and the Printer will be stopped. Service Station The Service Station consists of a linear motion mechanism with a chassis containing one PrintHead Cleaner (PHC) for each printhead. Each PHC consists of one spittoon and reservoir, sled-type cap nozzle wiper and pen snout wiper. Attached to the Service Station chassis, one optical drop detector provides nozzle check functionality. Wipers are located symmetrically on the PHC. This, together with the Scan-axis Printhead to Printhead distance (32 mm) enables separate color / black wipe. A positive pressure priming system is implemented that injects air into the printhead regulator bagafram to induce a controlled drooling. Airflow channels are integrated into the latching system springbeam, which deliver air to the bagafram ports. The priming pump is integrated into an articulating lever mounted on the right side of the service station. The priming process occurs with each printhead over its respective spittoon to handle waste ink and facilitate post-priming servicing routines. Print Head Cleaner (PHC) The PHC case is the main structural part of the replacement module. It is the part that the customer handles and contains the other subcomponents: n Wiper. n Spittoon. n Cleaning fluid. n Cap sled assembly. HP DesignJets 1050C and 1055CM Printers Service Manual 10-9