Patent ID: 7547084

Claim:
A method of operating a fluid ejection device having a plurality of fluid ejecting elements, wherein N of the plurality of fluid ejecting elements are arranged into a plurality of zones with each zone having at least one fluid ejecting element, the method comprising: storing a value being one of an enabling value or a disabling value in each of N memory elements of a shift register, each memory element corresponding to a different one of the N fluid ejecting elements; enabling each fluid ejecting element to eject fluid when the value stored in the corresponding memory element of the shift register is an enabling value; and controlling individually for each zone a duration that an enabling value is stored in each corresponding memory element of the zones, wherein the N memory elements comprise: a first set of N memory elements each having a different element position and storing a first enable value; a second set of N memory elements each having a different element position and storing a second enable value; and N combiners each having a first input coupled to one of the first set of N memory elements and a second input coupled to one of the second set of N memory elements having a same element position as the memory element of the first set of N memory elements coupled to the first input, each of the N combiners providing, at an output, an enable value having an enable state when the first and second enable values of corresponding memory elements of the first and second set of N memory elements both have an enable state, wherein each of the N combiners and the corresponding memory elements form a different one of the N memory elements.