Conventionally, ink jet heads employing a so-called “shared-wall head” system in which the partition walls of pressure chambers adjacent to each other serve as actuators are known. In the ink jet heads employing this system, pressure fluctuation, which is caused in the pressure chambers, deforms actuators and is spread to adjacent pressure chambers, and thus “crosstalk” is generated and variations are caused in the volume and speed of ink droplets which are ejected in accordance with an image pattern.
To cope with such problems, a technique is disclosed in which pressure fluctuation is purposely caused in pressure chambers which do not eject ink, by driving actuators with dummy pulses to compensate for changes in the volume and ejection speed of ink droplets due to crosstalk of the pressure fluctuation.
However, in the above-described conventional technique, since the pressure fluctuation which generates the crosstalk compensating for the change in ejection speed is restricted to a level where ink is not ejected from nozzles, it is difficult to obtain sufficient effects although changes in the volume and ejection speed due to the crosstalk can be reduced to a certain level.
In addition, in the above-described conventional technique, it is necessary to selectively supply to respective channels pulses for ejecting ink depending on the generation of dummy pulses and pulses with different voltages and a drive signal generating unit becomes complicated, so an inexpensive ink jet recording apparatus having high reliability cannot be provided.
In addition, a technique is disclosed in which the waveform of dummy pulses for correcting crosstalk is calculated on the basis of the response characteristics of the ink jet head and the dummy pulses of this waveform are provided to channels from which ink is not ejected. Although this technique is highly effective from the point of view of the elimination of crosstalk, a driving signal generating unit is required to generate an arbitrary waveform and thus the drive circuit becomes complicated and an inexpensive ink jet recording apparatus having high reliability cannot be provided.
In the conventional technique of correcting crosstalk, in order to set the appropriate crosstalk correction amount, the voltage amplitude of the driving signals for crosstalk correction is adjusted. Accordingly, a drive circuit of the conventional ink jet head is required to selectively supply to respective channels a drive voltage for correcting crosstalk as well as a drive voltage for ink ejection and thus the drive circuit becomes complicated.
The present invention is contrived in order to solve the above-described problems and an object of the invention is to provide a technique of reducing crosstalk, which is generated when employing a shared wall ink jet head, by simple drive control with lower power consumption than in the past.
USPTO Backgrounds
USPTO Backgrounds