Droplet ejection apparatus and a method of detecting and judging head failure in the same
First Claim
1. A droplet ejection apparatus comprising:
- a plurality of droplet ejection heads, each of the droplet ejection heads including;
a cavity filled with a liquid;
a nozzle communicating with the cavity; and
an actuator which changes an internal pressure of the cavity to eject the liquid in the form of droplets through the nozzle in response to the pressure changes;
a driving circuit which drives the actuator of each droplet ejection head;
a residual vibration detector detecting a residual vibration of an electromotive voltage generated from the actuator after the actuator has been driven by the driving circuit;
a pulse generator generating reference pulses;
an information processor carrying out a computation for the number of reference pulses generated by the pulse generator based on the residual vibration of the electromotive voltage detected by the residual vibration detector;
a time measurer measuring a lapsed time since the actuator has been driven by the driving circuit;
a head failure judge judging a head failure in the droplet ejection heads based on the computation result of the information processor and the lapsed time measured by the time measurer; and
a switch switching a connection of the actuator from the driving circuit to the residual vibration detector after carrying out the droplet ejection operation by driving the actuator.
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Abstract
It is an object of the invention to provide a droplet ejection apparatus and a method of detecting and judging a head failure that can detect an ejection failure and carry out appropriate recovery processing according to a cause thereof. The droplet ejection apparatus of the invention includes a plurality of droplet ejection heads, each of the droplet ejection heads including a diaphragm and an actuator which displaces the diaphragm; a driving circuit which drives the actuator of each droplet ejection head; residual vibration detecting means 16 for detecting a residual vibration of the diaphragm displaced by the actuator after the actuator has, been driven by the driving circuit; pulse generating means for generating reference pulses; computation means 17 for carrying out a computation for the number of reference pulses generated by the pulse generating means on the basis of the residual vibration of the diaphragm detected by the residual vibration detecting means; time measuring means for measuring a lapsed time since the actuator has been driven by the driving circuit; and head failure judging means 20 for judging a head failure in the droplet ejection heads on the basis of the computation result of the computation means 17 and the lapsed time measured by the time measuring means.
74 Citations
10 Claims
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1. A droplet ejection apparatus comprising:
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a plurality of droplet ejection heads, each of the droplet ejection heads including;
a cavity filled with a liquid;
a nozzle communicating with the cavity; and
an actuator which changes an internal pressure of the cavity to eject the liquid in the form of droplets through the nozzle in response to the pressure changes;
a driving circuit which drives the actuator of each droplet ejection head;
a residual vibration detector detecting a residual vibration of an electromotive voltage generated from the actuator after the actuator has been driven by the driving circuit;
a pulse generator generating reference pulses;
an information processor carrying out a computation for the number of reference pulses generated by the pulse generator based on the residual vibration of the electromotive voltage detected by the residual vibration detector;
a time measurer measuring a lapsed time since the actuator has been driven by the driving circuit;
a head failure judge judging a head failure in the droplet ejection heads based on the computation result of the information processor and the lapsed time measured by the time measurer; and
a switch switching a connection of the actuator from the driving circuit to the residual vibration detector after carrying out the droplet ejection operation by driving the actuator. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9)
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2. A method of detecting and judging a head failure in a droplet ejection apparatus, the method comprising the steps of:
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detecting a residual vibration of an electromotive voltage generated from an actuator in a droplet ejection head after carrying out a droplet ejection operation by driving the actuator with a driving circuit by switching a connection of the actuator from the driving circuit to a residual vibration detector;
generating reference pulses at the same time when detecting the residual vibration of the electromotive voltage;
carrying out an operation for the number of reference pulses generated based on the residual vibration of the electromotive voltage;
measuring a lapsed time since the actuator has been driven by the driving circuit; and
judging a head failure in the droplet ejection head based on the computation result and the measured lapsed time. - View Dependent Claims (10)
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Specification