Piezoelectric device, droplet jetting device using the same, and image output device

1. A piezoelectric device comprising:

a flexible substrate;

a piezoelectric element comprising a pair of electrodes, each of said pair of electrodes being disposed on said flexible substrate;

a switching element connected to one of said pair of electrodes; and

a common line connected to the other of said pair of electrodes,

wherein said piezoelectric element is provided on a surface of said flexible substrate while said switching element is provided in said flexible substrate.

2. The piezoelectric device according to claim 1 , wherein said switching element is a thin film transistor.

3. The piezoelectric device according to claim 1 , wherein a plurality of said piezoelectric elements are disposed in a matrix on said flexible substrate.

4. The piezoelectric device according to claim 1 , wherein said device further includes a supporting member for supporting said flexible substrate; and wherein said piezoelectric element is provided in a region between portions supported by said supporting member.

5. The piezoelectric device according to claim 4 , wherein said switching element is provided at a portion of said flexible substrate, supported by said supporting member.

6. The piezoelectric device according to claim 1 , wherein said flexible substrate is thinned.

7. The piezoelectric device according to claim 1 , wherein said device further includes a vibration plate provided separately from said flexible substrate and in contact with said piezoelectric element.

8. The piezoelectric device according to claim 1 , wherein said device further includes a circuit for sending an electric signal to said piezoelectric element to control its operation; and said switching element is provided between said piezoelectric element and said circuit.

9. The piezoelectric device according to claim 1 , wherein said device further includes a circuit for receiving an electric signal from said piezoelectric element to read its operation; and said switching element is provided between said piezoelectric element and said circuit.

10. A droplet jetting device, comprising:

a liquid housing part for housing a liquid;

a nozzle connected to said liquid housing; and

a piezoelectric device according to claim 1 configured so as to apply a pressure to said liquid housed in said liquid housing part.

11. An image output device for outputting an image by spraying droplets, wherein said image output device includes a droplet jetting device according to claim 10 .

12. A method for driving the piezoelectric device according to claim 1 comprising: turning on said switching element according to a control signal; supplying a data signal to said piezoelectric element; and vibrating a movable region of said flexible substrate by transmitting movement of said piezoelectric element.

13. A method for driving the piezoelectric device according to claim 9 comprising: transforming said piezoelectric element according to an external force; and outputting an electric signal from said piezoelectric element through said switching element.

14. A method for driving the droplet jetting device according to claim 10 comprising:

turning on said switching element according to a control signal;

supplying a data signal to said piezoelectric element;

vibrating a movable region of said flexible substrate by transmitting movement of said piezoelectric element; and

jetting a droplet from said nozzle according to a pressure rising in said liquid housing.