Bubble Jet Head - Canon BJ-W7000 Service Manual

es CHAPTER 2OPERATION al
2. Bubble Jet Head
After dust is filtered by the mesh ink filter, ink in the ink sponge is send to the bubble jet nozzles via the
joint pipe of the cartridge body.
When head drive current flows to the heater plate in the nozzles, the ink boils to generate lots of bubbles.
Finally, these bubbles boil to form on one single bubble. The head drive current is stopped before the ink
droplet leaves the nozzle. Bubbles continue to be formed by residual heat in the heater, and ink droplets are
sprayed from the nozzle tips.
After the ink droplet is sprayed, the nozzles are filled again with ink from the ink sponge by capillary action
and cool the heater.
Figure 2-302
@® Ink filter Nozzle holes
@® Joint pipe @® Heater plate
© Plastic cover
@@ Aluminum base plate
® Ink chamber @ Silicon plate
© Face plate @ PcB
© Ink droplets
® Signal circuit
@ Bubble