DROPLET DISCHARGING HEAD, IMAGE FORMING APPARATUS, AND FILM FORMING APPARATUS

Abstract

A droplet discharging head includes a diaphragm, a fixing plate, and a piezoelectric element. The piezoelectric element includes a first electrode, a second electrode, a piezoelectric body layer interposed between the first and second electrodes, a first internal electrode extending from the first electrode between the first and second electrodes, and a second internal electrode extending from the second electrode between the first and second electrodes. At least a part of a first end face of the piezoelectric element is in contact with the diaphragm. The first end face includes a first end of the first electrode, a first end of the second electrode, and a first end of the piezoelectric body layer. At least a part of a second end face of the piezoelectric element is in contact with the fixing plate. The second end face includes a second end of the first electrode and a second end of the piezoelectric body layer. At least a part of the first end of the piezoelectric body layer lies between the diaphragm and the first end of the second electrode. At least a part of the second end of the piezoelectric body layer lies between the fixing plate and a second end of the second electrode. The piezoelectric body layer includes an active layer that overlaps both the first and second internal electrodes, a first inactive layer that overlaps only the first internal electrode, and a second inactive layer that overlaps only the second internal electrode. A thickness of the second inactive layer between the second electrode and the active layer is larger than a thickness of the first inactive layer between the first electrode and the active layer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanying drawings, where like numbers reference like elements.

FIG. 1 is a schematic sectional view of a droplet discharging head according to a first embodiment of the invention.

FIG. 2 is a schematic sectional view showing an example of a piezoelectric element used for the droplet discharging head.

FIGS. 3A to 3E are partial schematic sectional views showing positional relations among a diaphragm, a fixing plate, and the piezoelectric element.

FIGS. 4A and 4B are schematic sectional views showing the respective thicknesses of a first inactive layer and a second inactive layer are different from each other depending on the disposition of the piezoelectric element.

FIG. 5 is a schematic oblique perspective view showing a film forming apparatus that is one form of a droplet discharging apparatus.

FIG. 6 is a schematic oblique perspective view showing an image forming apparatus that is one form of a droplet discharging apparatus.

Claims

1. A droplet discharging head comprising: a piezoelectric element that includes a first electrode, a second electrode, a piezoelectric body layer interposed between the first and second electrodes, a first internal electrode extending from the first electrode between the first and second electrodes, and a second internal electrode extending from the second electrode between the first and second electrodes, the piezoelectric body layer including an active layer that is overlapping both the first and second internal electrodes, the piezoelectric body layer including a first inactive layer that is overlapping only the first internal electrode, the piezoelectric body layer including a second inactive layer that is overlapping only the second internal electrode, a thickness of the second inactive layer between the second electrode and the active layer being larger than a thickness of the first inactive layer between the first electrode and the active layer;a diaphragm that is in contact with at least a part of a first end face of the piezoelectric element, the first end face including a first end of the first electrode, a first end of the second electrode, and a first end of the piezoelectric body layer, at least a part of the first end of the piezoelectric body layer lying between the diaphragm and the first end of the second electrode; anda fixing plate that is in contact with at least a part of a second end face of the piezoelectric element, the second end face including a second end of the first electrode and a second end of the piezoelectric body layer, at least a part of the second end of the piezoelectric body layer lying between the fixing plate and a second end of the second electrode.

2. A droplet discharging head comprising: a piezoelectric element that includes a first electrode, a second electrode, and a piezoelectric body layer interposed between the first and second electrodes;a diaphragm that is in contact with at least a part of a first end face of the piezoelectric element, the first end face including a first end of the second electrode and a first end of the piezoelectric body layer, the diaphragm being in contact with the first end of the second electrode; anda fixing plate that is in contact with at least a part of a second end face of the piezoelectric element, the second end face including a second end of the second electrode and a second end of the piezoelectric body layer, at least a part of the second end of the piezoelectric body layer lying between the fixing plate and the second end of the second electrode.

3. The droplet discharging head according to claim 2, the first end face including a first end of the first electrode, at least a part of the first end of the piezoelectric body layer lying between the diaphragm and the first end of the first electrode.

4. A droplet discharging head comprising: a piezoelectric element, the piezoelectric element that includes a first electrode, a second electrode, and a piezoelectric body layer interposed between the first and second electrodes;a diaphragm that is in contact with at least a part of a first end face of the piezoelectric element, the first end face including a first end of the second electrode and a first end of the piezoelectric body layer, at least a part of the first end of the piezoelectric body layer lying between the diaphragm and the first end of the second electrode; anda fixing plate that is in contact with at least a part of a second end face of the piezoelectric element, the second end face including a second end of the piezoelectric body layer.

5. The droplet discharging head according to claim 4, the first end face of the piezoelectric element including a first end of the first electrode, at least a part of the first end of the piezoelectric body layer lying between the diaphragm and the first end of the first electrode.

6. The droplet discharging head according to claim 2, the first end face of the piezoelectric element including a first end of the first electrode, the first end of the first electrode being in contact with the diaphragm.

7. The droplet discharging head according to claim 1, the second end face of the piezoelectric element including a second end of the first electrode, the fixing plate being in contact with the second end of the first electrode.

8. The droplet discharging head according to claim 4, the second end face of the piezoelectric element including a second end of the second electrode, at least a part of the second end of the piezoelectric body layer lying between the fixing plate and a second end of the second electrode.

9. The droplet discharging head according to claim 2, the second end face of the piezoelectric element including the second end of the second electrode, the diaphragm being in contact with the first end of the second electrode.

10. The droplet discharging head according to claim 4, the second end face of the piezoelectric element including a second end of the second electrode, the fixing plate being in contact with the second end of the second electrode.

11. The droplet discharging head according to claim 2, the fixing plate being conductive.

12. The droplet discharging head according to claim 3, the diaphragm being conductive.

13. The droplet discharging head according to claim 1, the second electrode being coupled to a printed board.

14. The droplet discharging head according to claim 1, at least the part of the first end face of the piezoelectric element being in contact with a protrusion of the diaphragm.

15. The droplet discharging head according to claim 2, wherein: the piezoelectric element includes a first internal electrode extending from the first electrode between the first and second electrodes and a second internal electrode extending from the second electrode between the first and second electrodes;the piezoelectric body layer includes an active layer that overlaps both the first and second internal electrodes, a first inactive layer that overlaps only the first internal electrode, and a second inactive layer that overlaps only the second internal electrode; anda thickness of the first inactive layer between the first electrode and the active layer and a thickness of the second inactive layer between the second electrode and the active layer are different from each other.

16. The droplet discharging head according to claim 1, further comprising: a base coupled to the diaphragm, the base including a pressure chamber that retains a liquid material, and a portion defining an discharging port through which the liquid material is discharged.

17. The droplet discharging head according to claim 1, further comprising: a flow channel substrate coupled to the diaphragm, the flow channel substrate including a pressure chamber, the pressure chamber retaining a liquid material; anda nozzle plate coupled to the flow channel substrate, the nozzle plate including a portion defining an discharging port through which the liquid material is discharged.

18. An image forming apparatus comprising the droplet discharging head according to claim 1.

19. A film forming apparatus comprising the droplet discharging head according to claim 1.