An ink jet print head has a bubble collecting device in an ink liquid chamber between a filter and an ink ejection opening for ejecting ink, a bubble moving device for moving bubbles to the bubble collecting device, and a bubble discharging device for discharging bubbles accumulated in the bubble collecting...http://www.google.com.au/patents/US6626528?utm_source=gb-gplus-sharePatent US6626528 - Ink jet print head with bubble discharge
