Each of branched ink supply passages 42ai to 42an and 42bi to 42bn in a driving substrates 32 is constituted of a parallel passage portion 46a and a narrow passage portion 48a. An ink from an ink supply opening 32a is supplied to a receptacle portions 50 respectively receiving heater portions 32ai to...http://www.google.com.au/patents/US6174049?utm_source=gb-gplus-sharePatent US6174049 - Bubble jet head and bubble jet apparatus employing the same
