Inkjet apparatus

1. An inkjet apparatus comprising:

a plurality of nozzles that eject ink droplets;

a plurality of piezoelectric elements provided in one-to-one correspondence with the plurality of nozzles, each of the plurality of piezoelectric elements applying pressure to a corresponding nozzle to eject ink droplets therefrom in response to an applied drive voltage;

a drive voltage generator that generates a drive voltage having a waveform;

a data processor into which is inputted both waveform adjustment data indicating a desired waveform to be applied to a piezoelectric element and ejection signals indicating whether or not each nozzle ejects an ink droplet, the data processor transferring the waveform adjustment data and the ejection signals, each of the plurality of piezoelectric elements being controlled whether or not to apply pressure to a corresponding nozzle based on the ejection signals transferred from the data processor; and

an adjustment unit that adjusts the waveform of the drive voltage for each piezoelectric element based on the waveform adjustment data transferred from the data processor and transfers the adjusted waveform to each of the plurality of piezoelectric elements,

wherein a group of ink droplets is ejected from a prescribed number of nozzles during a prescribed time period based on both the adjusted waveform and the ejection signal, and the ink droplets in the group blend with each other to attain a leveling effect, and

wherein a weight of the group of ink droplets changes depending on assortments of the adjusted waveforms and the ejection signals, the waveform adjustment data and the ejection signals being inputted into the data processor such that the weight of the ink droplets in the group is the closest to a target weight.

2. The inkjet apparatus according to claim 1 , wherein the plurality of piezoelectric elements is actuated substantially simultaneously.

3. The inkjet apparatus according to claim 1 , wherein the drive voltage generator generates a number of drive voltages having different waveforms, the number of drive voltages generated by the drive voltage generator being less than a number of nozzles.

4. The inkjet apparatus according to claim 1 , wherein the drive voltage generator generates a single drive voltage having a predetermined waveform.

5. The inkjet apparatus according to claim 1 , wherein both the waveform adjustment data and the ejection signal are digital signals.

6. The inkjet apparatus according to claim 1 , wherein the plurality of nozzles are aligned at an equi-pitch, and the prescribed number of nozzles is aligned one after another.

7. The inkjet apparatus according to claim 1 , further comprising a memory that stores combined data that is a combination of the waveform adjustment data and the ejection signal both transferred from the data processor, and transfers the combined data stored in the memory to the adjustment unit repeatedly.

8. The inkjet apparatus according to claim 7 , further comprising a selector that selectively transfers one of the combined data stored in the memory and the combined data transferred directly from the data processor to the adjustment unit based on a select signal input to the selector from the data processor.

9. The inkjet apparatus according to claim 1 , further comprising:

a memory that stores combined data that is a combination of the waveform adjustment data and the ejection signal both transferred from the data processor, and transfers the combined data stored in the memory to the adjustment unit repeatedly; and

a gate connected to the adjustment unit, the gate prohibiting the combined data stored in the memory from passing to the adjustment unit based on an instruction from the data processor.

10. The inkjet apparatus according to claim 9 , further comprising a selector that selectively transfers one of the combined data stored in the memory and the combined data transferred directly from the data processor to the memory based on a select signal input to the selector from the data processor.

11. The inkiest apparatus according to claim 1 , further comprising:

an XYZ stage transporting a substrate proximate to said plurality of nozzles; and

an XYZ controller controlling a movement of the XYZ stage in response the data processor, wherein the drive voltage applied to each of the plurality of piezoelectric elements is controlled based on the waveform adjustment data and the ejection signal so that a total weight of ink droplets ejected from a prescribed number of nozzles during a period of time when a predetermined number of ejection signals are generated is closest to a target weight and all the ink droplets blend with each other to attain a leveling effect and form a uniform film on the substrate.