Canon BJC 6000 Service Manual - Page 76

Part 4: Technical Reference BJC-6000 1.4 Print Driving The printer sends the control signals to the head in order to allow the head to discharge ink for printing. These signals consist of the drive control signals that cause ink to be discharged from the head nozzles, and the thermal control signal that controls the head temperature to ensure constant ink discharge. Both control signals are optimized by the printer controller and sent via the carriage ribbon cable contact section to the head for optimal printing. 1.4.1 Print drive control a) Black BJ cartridge control The Black BJ cartridge has 160 nozzles. Each nozzle has two heater boards in an array, large and small, one in front, the other in the rear. The front and rear heaters will be controlled to provide multi-drop driving, with both driven simultaneously to discharge a large drop, or with only the small one driven to discharge a small drop. The head's 160 nozzles are divided into 10 blocks (16 nozzles per block), with all blocks driven simultaneously, one nozzle per block in High Speed/Standard mode, or 20 nozzles per block in all other cases. The Heat ENABLE signals (HENB 0, 1, 2, 3) are the heater board's drive control signals. These signals are always fed to the head during printing, using the Block ENABLE signals (BENB 0,1), Even/Odd ENABLE signal (Even/Odd ENB), and the Heat Select signals (HSEL1A0, 1A1, 1B0, 1B1, 2A0, 2A1, 2B0, 2B1) to select the heaters to turn on. Turning HENB 0 and 2 on drives the Black BJ cartridge's large heater while HENB 1 and 3 drive the small heater. A Heat ENABLE signal consists of a pre-pulse and main pulse so that heater drive pulse width can be adjusted according to the monitored head rank and internal temperature, etc., to always ensure optimum ink discharge. HSEL1A/1B HSEL2A/2B HSEL1A/1B HSEL2A/2B HSEL1A/1B HSEL2A/2B HSEL1A/1B HSEL2A/2B BE0 O E BE1 O E BE2 O E BE3 O E BE0 O E BE1 O E BE2 O E BE3 O E A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B A/B C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D C/D : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 144 /160 BE0 - BE3: Block ENABLE 1 - 8 E: Even ENABLE A: Heat Select 1A C: Heat Select 2A O: Odd ENABLE B: Heat Select 1B D: Heat Select 2B Figure4-4 Printing Sequence (Black BJ cartridge, HQ mode) 4-4