Canon BJC 50 Service Manual - Page 115

BJC-50 Part 4: Technical Reference b) Purging Purging is performed to correct/prevent the non-ejection of ink, which is caused by unnecessary bubbles and dust on the head faceplate. The cap and pump in the purge section are used for purging operation. c) Capping Capping operation is performed to correct/prevent the non-ejection of ink, which is caused by the dried-up of ink inside nozzles. Cap is pressed against the head faceplate when the carriage moves to the home position. When the cap moves away from the faceplate, waste ink in the cap is sucked by purging operation. The sucked ink is absorbed by the absorber in the pump and finally absorbed by the waste ink absorber. Capping is performed in the following cases: 1. When the printer is turned off with the POWER button 2. When the printer receives no data or commands for 1 minute while paper is set in the paper feeder. d) Wiping Wiping operation is performed to correct/prevent the non-ejection of ink, which is caused by paper-powder on the head faceplate or by the foreign materials in ink. The wiper is set and released by wiping hooks on the carriage. When the carriage moves from the home position, the wiper touches the aluminum plate of the head, removes the stain from the wiper and then wipes off the ink from the faceplate. Wiping operation is performed in the following cases: 1. When the number of dots printed or the print time exceeds the preset value during printing 2. After purging 3. Before capping Carriage Latch Lever BJ Head Hooks Wiper Lever Wiper 1. Wiper is set. 2. Wiper is released. Figure 4-20 Wiping Function e) Maintenance jet The maintenance jet is performed during cleaning to remove bubbles inside nozzles and the dust near ink ejection apertures. In this operation, the ink is ejected from the head into the cap and sucked into the waste ink absorber through the pump section. 4-27