US 7,320,509 B2
Inkjet apparatus
Shinya Kobayashi, Hitachinaka (Japan); Takahiro Yamada, Hitachinaka (Japan); and Hitoshi Kida, Hitachinaka (Japan)
Assigned to Ricoh Printing Systems, Ltd., Tokyo (Japan)
Filed on Mar. 15, 2005, as Appl. No. 11/79,774.
Claims priority of application No. P2004-073323 (JP), filed on Mar. 15, 2004.
Prior Publication US 2005/0200639 A1, Sep. 15, 2005
Int. Cl. B41J 29/38 (2006.01)
U.S. Cl. 347—10  [347/6; 347/9] 11 Claims
OG exemplary drawing
 
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.