Nozzle plate, liquid discharge head, liquid discharge device, and apparatus for discharging liquid

Patent metadata

Field	Value
Publication number	US-10252526-B2
Application number	US-201515510763-A
Country	US
Kind code	B2
Filing date	Oct 22, 2015
Priority date	Oct 25, 2014
Publication date	Apr 9, 2019
Grant date	Apr 9, 2019

Abstract

A nozzle plate includes a nozzle base member including a plurality of nozzle holes formed therethrough, the plurality of nozzle holes serving as nozzles that discharge droplets; and a liquid-repellent film of a liquid-repellent material formed on a droplet discharge surface of the nozzle base member, the liquid-repellent material containing a liquid-repellent group. Each of the plurality of nozzle holes includes a straight hole part, the straight hole part extending from the droplet discharge surface of the nozzle base member and having a constant diameter in a thickness direction of the nozzle base member. The liquid-repellent group contained in the liquid-repellent material is attached to an inner nozzle wall of the straight hole part. When the nozzle hole is supplied with pure water, a meniscus of the pure water stays in the straight hole part.

First claim

The invention claimed is:

1. A liquid discharge apparatus configured to perform discharge operation to discharge liquid, comprising:
a liquid supply to supply a liquid;
a nozzle base member including a plurality of nozzle holes formed therethrough, the plurality of nozzle holes serving as nozzles that, during the discharge operation of the liquid discharge apparatus, discharge droplets of the liquid supplied by the liquid supply; and
a liquid-repellent film of a liquid-repellent material formed on a droplet discharge surface of the nozzle base member, the liquid-repellent material containing a liquid-repellent group,
wherein each of the plurality of nozzle holes includes a straight hole part, the straight hole part extending from the droplet discharge surface of the nozzle base member and having a constant diameter in a thickness direction of the nozzle base member,
wherein the liquid-repellent group contained in the liquid-repellent material is attached to an inner nozzle wall of the straight hole part,
wherein for at least one nozzle hole, a central axis of the straight hole part of the nozzle hole is inclined by an inclination angle α relative to a direction perpendicular to the droplet discharge surface of the nozzle base member, where 0°≤α<90°, and
wherein the nozzle hole is disposed and configured with a length L of the straight hole part, a diameter D of the nozzle hole, and a distance X from the droplet discharge surface to a liquid level of the liquid within the nozzle hole when the liquid is not being discharged from the plurality of nozzle holes, to comport with the following formula (1):
L ·cos α−( D ·tan α)/2> X ·cos α  (1).

2. The liquid discharge apparatus as claimed in claim 1 , wherein when the liquid supply supplies pure water, as the liquid, to the nozzle hole, a meniscus of the pure water stays in the straight hole part before a next discharge from the nozzle hole.

3. The liquid discharge apparatus as claimed in claim 1 , wherein a region where a static contact angle θ with the liquid is 90° or more exists only in the straight hole part.

4. The liquid discharge apparatus as claimed in claim 1 , wherein a film thickness of the liquid-repellent film is 5-30 nm.

5. The liquid discharge apparatus as claimed in claim 1 , further comprising a plurality of concavities formed on the droplet discharge surface of the nozzle base member, wherein the liquid-repellent material that forms the liquid-repellent film is held with flowability in the concavities.

6. The liquid discharge apparatus as claimed in claim 1 , wherein the liquid to be discharged from the liquid discharge apparatus includes a surface active agent and has a static surface tension of 30×10 −2 N/m or less.

7. A nozzle plate comprising:
a nozzle base member including at least one nozzle hole formed therethrough, to discharge liquid; and
a liquid-repellent film of a liquid-repellent material containing a liquid-repellent group,
wherein the nozzle hole includes (i) a straight hole part and (ii) a tapered part,
wherein the liquid-repellent group contained in the liquid-repellent material is attached to the straight hole part and the tapered part,
a central axis of the straight hole part is inclined by an inclination angle α (0°≤α<90°) relative to a direction perpendicular to a discharge surface of the nozzle base member, and
wherein the nozzle hole is configured to satisfy the following formula (1):
L ·cos α−( D ·tan α)/2> X ·cos α  (1),

where
a length of the straight hole part of the nozzle hole is L (μm),
a diameter of the straight hole part of the nozzle hole is D (μm),
a distance from the droplet discharge surface of the nozzle base member to a liquid level of the liquid within the nozzle hole is X (μm).

8. The nozzle plate as claimed in claim 7 , wherein a region where a static contact angle θ with the liquid is 90° or more exists only in the straight hole part.

9. The nozzle plate as claimed in claim 7 , wherein a film thickness of the liquid-repellent film is 5-30 nm.

10. The nozzle plate as claimed in claim 7 , further comprising a plurality of concavities formed on a droplet discharge surface of the nozzle base member, wherein the liquid-repellent material that forms the liquid-repellent film is held with flowability in the concavities.

11. A liquid discharge head comprising the nozzle plate as claimed in claim 7 .

12. A liquid discharge device comprising the liquid discharge head as claimed in claim 11 .

13. The liquid discharge device as claimed in claim 12 , wherein the liquid discharge head is integrated with at least one of a head tank that stores liquid to be supplied to the liquid discharge head, a carriage that carries the liquid discharge head, a supply mechanism that supplies liquid to the head tank, a maintenance and recovery mechanism that maintains and recovers the liquid discharge head, and a main-scanning movement mechanism that moves the liquid discharge head in a main-scanning direction.

14. An apparatus for discharging liquid, the apparatus comprising the liquid discharge head as claimed in claim 11 .

15. The apparatus for discharging liquid as claimed in claim 14 , wherein liquid to be discharged from the liquid discharge head includes a surface active agent and has a static surface tension of 30×10 −2 N/m or less.

Assignees

• Tamai Tomohiro
• Ricoh Co Ltd

Inventors

• Tamai Tomohiro

Classifications

• B41J2002/14475

  characterised by nozzle shapes or number of orifices per chamber · CPC title

• B41J2/1612

  of stacked structure type, deformed by compression/extension and disposed on a diaphragm · CPC title

• B41J2002/14403

  including a filter · CPC title

• B41J2/1629

  wet etching · CPC title

• B41J2/1606

  Coating the nozzle area or the ink chamber · CPC title