Liquid ejection head and liquid ejection apparatus

A liquid ejection apparatus for ejecting a liquid onto a medium, the liquid ejection apparatus comprising:

• a conveyer for conveying the medium;
• and
• a liquid ejection head configured to eject the liquid onto the conveyed medium, wherein
• the liquid ejection head includes:
• a nozzle plate having a plurality of nozzles arranged in a first direction,
• a plurality of pressure chambers that respectively communicate with the nozzles, a volume of each of the pressure chambers being varied to eject the liquid through the corresponding nozzle,
• an actuator configured to vary the volumes of the pressure chambers independently according to drive waveforms respectively applied to the pressure chambers, and
• a drive circuit configured to generate a drive waveform for each of the pressure chambers with a delay time to cause the liquid to be ejected through the corresponding nozzle with the delay time, and
• the drive circuit is configured to determine the delay time for a drive waveform for a particular pressure chamber to be a sum of:
• a first delay time for the particular pressure chamber, wherein the first delay time for all the pressure chambers varies so as to have a triangular wave shape with respect to positions of the pressure chambers in the first direction, and
• a second delay time for the particular pressure chamber, wherein the second delay time for all the pressure chambers varies so as to have a periodic wave shape with respect to the positions of the pressure chambers in the first direction, a periodicity of the wave shape of the second delay time being different from a periodicity of the wave shape of the first delay time.