A liquid jet apparatus comprises a recording head including a plurality of discharge ports for discharging the liquid therethrough, and a plurality of energy generating units respectively arranged correspondingly to the plural discharge ports for generating energy used for discharging the liquid. A driving...http://www.google.com.au/patents/US4866462?utm_source=gb-gplus-sharePatent US4866462 - Liquid jet recording apparatus capable of being driven at selected different frequencies
