Head Drive Unit And Inkjet Printer

A head drive unit comprising:

• an inkjet head driven based on a drive signal;
• and
• a head drive apparatus that outputs a discharge signal to the inkjet head based on image data and a print timing signal that are input from an external apparatus, and discharges a droplet from a nozzle to form an image on a recording medium,
• wherein the head drive apparatus comprises:
• a drive signal output unit for outputting either the discharge signal used for discharging a droplet from the nozzle to form an image or a flushing signal used for forcedly discharging a droplet from the nozzle without forming an image as a drive signal to the inkjet head;
• a cycle generation unit for generating a cyclic flushing timing signal for the flushing signal;
• an input interruption detection unit for detecting that no input is made and input of the print timing signal is interrupted even though a preset time has elapsed by monitoring input of the print timing signal;
• and
• a drive signal selection unit for selecting the flushing signal as the drive signal output from the drive signal output unit and continuously applying the flushing signal to all the nozzles of the inkjet head in synchronization with the flushing timing signal when the input interruption detection unit detects that input of the print timing signal has been interrupted.

A head drive unit comprising:

• an inkjet head driven based on a drive signal;
• and
• a head drive apparatus that outputs a discharge signal to the inkjet head based on image data and a print timing signal that are input from an external apparatus, and discharges a droplet from a nozzle to form an image on a recording medium,
• wherein the head drive apparatus comprises:
• a drive signal output unit for outputting either the discharge signal used for discharging a droplet from the nozzle to form an image or a meniscus oscillation signal for an oscillating liquid surface at a tip of the nozzle without discharging a droplet from the nozzle or a flushing signal used for forcedly discharging a droplet from the nozzle without forming an image to the inkjet head;
• a cycle generation unit for generating at least either a cyclic oscillation timing signal for the meniscus oscillation signal or a cyclic flushing timing signal for the flushing signal;
• an input interruption detection unit for detecting that no input is made and input of the print timing signal is interrupted even though a preset time has elapsed by monitoring input of the print timing signal;
• and
• a drive signal selection unit for selecting the meniscus oscillation signal or the flushing signal as the drive signal output from the drive signal output unit and continuously applying the selected signal to all the nozzles of the inkjet head in synchronization with the oscillation timing signal or the flushing timing signal when the input interruption detection unit detects that input of the print timing signal has been interrupted.