Droplet jetting apparatus and display device manufacturing method

1. A droplet jetting apparatus, comprising:

an actuator becoming deformed by a command waveform application;

an elastic body adhered to the actuator and becoming deformed in response to a deformation of the actuator;

an ink chamber filled with ink, jetting a droplet of the ink in response to a deformation of the elastic body;

a voltage information acquirer acquiring a voltage waveform of the actuator just after the command waveform has begun to fall down; and

a sense/decider sensing at least any of an abnormality in the ink chamber, a failure of the actuator, and a defective adhesion between the actuator and the elastic body based on the acquired voltage waveform, and deciding whether or not the ink is being jetted normally.

2. The droplet jetting apparatus according to claim 1 , further comprising:

a memory storing previously a normal time voltage waveform of the actuator indicating that the ink is being jetted normally; and

wherein the sense/decider compares the voltage waveform with the normal time voltage waveform, senses at least any of the abnormality in the ink chamber, the failure of the actuator, and the defective adhesion between the actuator and the elastic body, and decides whether or not the ink is being jetted normally.

3. The droplet jetting apparatus according to claim 1 , further comprising:

a voltage application stopper stopping the command waveform application to the actuator when it is decided that the ink is not being jetted normally.

4. The droplet jetting apparatus according to claim 1 , further comprising:

a memory storing previously a normal time voltage waveform of the actuator indicating that the ink is being jetted normally; and

wherein

the sense/decider calculates a lower limit value of the normal time voltage waveform and a lower limit value of the voltage waveform, calculates a difference between the lower limit value of the normal time voltage waveform and the lower limit value of the voltage waveform, senses at least any of the abnormality in the ink chamber, the failure of the actuator, and the defective adhesion between the actuator and the elastic body based on the difference, and decides whether or not the ink is being jetted normally.

5. The droplet jetting apparatus according to claim 1 , further comprising:

a memory storing previously a normal time voltage waveform of the actuator indicating that the ink is being jetted normally; and

wherein

the sense/decider calculates a power spectrum by applying a Fourier transform to the normal time voltage waveform, calculates a peak value by applying the Fourier transform to the voltage waveform, calculates a power value at a frequency of the peak value from the power spectrum, calculates a difference between the peak value and the power value, senses at least any of the abnormality in the ink chamber, the failure of the actuator, and the defective adhesion between the actuator and the elastic body based on the difference, and decides whether or not the ink is being jetted normally.

6. The droplet jetting apparatus according to claim 1 , wherein the voltage information acquirer acquires the voltage waveform when the ink chamber is jetting the droplet.

7. The droplet jetting apparatus according to claim 1 , wherein the voltage information acquirer acquires the voltage waveform which is a residual oscillation waveform of the actuator.

8. The droplet jetting apparatus according to claim 1 , wherein the sense/decider applies a Fourier transform to the voltage waveform.

9. The droplet jetting apparatus according to claim 1 , wherein the voltage information acquirer senses a rising point of the command waveform and acquires the voltage waveform within an information acquiring time period when a set time period passes since a sense timing of the rising point, the information acquiring time period is set to be able to acquire the voltage waveform just after the command waveform has began to fall down.