Droplet generator and ink-jet recording device using thereof

Abstract

A droplet generator comprising a first unit having an elongate liquid chamber one end thereof is open and at least one raw of orifices disposed in a line oppositely to the open end in the longitudinal direction of the first unit, a second unit having an elongate diaphragm provided on the bottom of the second unit and a plurality of vibrators provided within the diaphragm area, a vibrating apparatus provided on the top of the vibrators, and a stationary section to fix the vibrating apparatus; wherein

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the external view and the internal structure of a droplet generator which is an embodiment of this invention.

FIG. 2 is a magnified view of part A of the cut-away area of FIG. 1 for explanation of the details.

FIG. 3 shows a magnified view of part B of FIG. 1 to explain details of the ink chamber and orifices.

FIG. 4 shows the transverse sectional view of the center part of the droplet generator in FIG. 1.

FIG. 5 shows the longitudinal sectional view of the center part of the droplet generator in FIG. 1.

FIG. 6 shows the cross sectional view taken along the line C-C of FIG. 5 to explain the relationship of the resonator, the diaphragm, and the ink chamber.

FIG. 7 shows graphs representing relationships between vibration frequency and amplitude amplification ratio to explain the effect of steps provided on the resonance vibration member.

FIG. 8 shows the appearance and the internal structure of the ink-jet head equipped with the droplet generator of this invention.

FIG. 9 shows the transverse sectional views of the center part of the ink-jet head of FIG. 8.

FIG. 10 is the magnified view of FIG. 9 to explain the flying status of ink droplets.

FIG. 11 shows the longitudinal sectional view of the center part of the ink-jet head of FIG. 8.

FIG. 12 shows the configuration of the whole ink-jet apparatus equipped with the ink-jet head of this invention.

Claims

1. A droplet generator comprising a first unit having an elongate liquid chamber one end thereof is open and at least one raw of orifices disposed in a line oppositely to the open end in the longitudinal direction of the first unit, a second unit having an elongate diaphragm provided on the bottom of the second unit and a plurality of vibrators provided within the diaphragm area, a vibrating apparatus provided on the top of the vibrators, and a stationary section to fix the vibrating apparatus; wherein the diaphragm of the second unit is provided closely and oppositely to the open end of the liquid chamber of the first unit.

2. The droplet generator of claim 1, wherein the plurality of vibrators are formed by a plurality of columnar structures disposed in the longitudinal direction of the elongate diaphragm.

3. The droplet generator of claim 2, wherein one end of the plurality of columnar structures opposite to the diaphragm is combined in a body with a structure having a preset area.

4. The droplet generator of any of claims 1 to 3, wherein the vibrating apparatus is made of a lamination of 2 or more layers of piezoelectric elements.

5. The droplet generator of claim 1, wherein the liquid chamber of the first unit contains at least one step on the wall between the open end and the orifices.

6. The droplet generator of claim 1, wherein the liquid chamber of the first unit provides with a multiple of steps in the direction of liquid flowing from orifices.

7. The droplet generator of claim 5 or 6, wherein the positions and intervals of steps in the elongate liquid chamber of the first unit are determined so that the distance between the open end and the step, the distance between orifices and the step, and the step-step distance may be a little shorter than the wavelength of vibration to be expected from the vibration frequency and the acoustic velocity of the liquid to be used.

8. The droplet generator of claim 5 or 6, wherein the positions and intervals of steps in the elongate liquid chamber of the first unit are determined so that some of the distance between the open end and the step, the distance between orifices and the step, and the step-step distance may be a little shorter than the wavelength of vibration to be expected from the vibration frequency and the acoustic velocity of the liquid to be used and others of the distances may be a little longer than thereof.

9. The droplet generator of claim 2, wherein the plurality of columnar structures provide with at least one step.

10. The droplet generator of any of claims 1 to 9, wherein the vibrating apparatus applies vibrations of some kHz to some 10 kHz to eject a plurality of liquid droplets continuously.

11. A droplet generator comprising an elongate liquid chamber, a plurality of orifices disposed at least in one line at one end of the liquid chamber, a diaphragm provided oppositely to the surface contains orifices of the liquid chamber, a plurality of vibrators provided on the diaphragm opposite to the liquid chamber, and a vibrating apparatus to vibrate the vibrators.

12. An ink-jet recording device comprising a first unit having an elongate liquid chamber one end thereof is open and at least one raw of orifices disposed in a line oppositely to the open end in the longitudinal direction of the first unit, a second unit having an elongate diaphragm provided on the bottom of the unit and a plurality of vibrators within the diaphragm area, a vibrating apparatus provided on the top of the vibrators, and a stationary section to fix the vibrating apparatus; wherein the diaphragm of the second unit is provided closely and oppositely to the open end of the liquid chamber of the first unit, and further comprises a plurality of electrode provided along the ejection of liquid droplets outside the orifices to selectively charge liquid droplets ejected from the orifices, an electrode apparatus to change the charged droplets and a gutter-like recovery apparatus to recover liquid droplets.