Liquid discharge head and liquid discharge apparatus

Patent metadata

Field	Value
Publication number	US-10894265-B2
Application number	US-201916543895-A
Country	US
Kind code	B2
Filing date	Aug 19, 2019
Priority date	Sep 27, 2018
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

A liquid discharge head includes: individual channels respectively including nozzles; a supply channel allowing an outlet of a storage chamber storing a liquid to communicate with an inlet of each of the individual channels; a return channel allowing an outlet of each of the individual channels to communicate with an inlet of the storage chamber; a return filter provided in the return channel; and a return branching channel branching off from a return upstream portion of the return channel. The return upstream portion is positioned upstream of the return filter.

First claim

What is claimed is:

1. A liquid discharge head, comprising:
a plurality of individual channels respectively including a plurality of nozzles;
a supply channel allowing an outlet of a storage chamber storing a liquid to communicate with an inlet of each of the individual channels;
a return channel allowing an outlet of each of the individual channels to communicate with an inlet of the storage chamber;
a return filter provided in the return channel; and
a return branching channel branching off from a return upstream portion of the return channel to communicate between the return upstream portion and the inlet of the storage chamber, the return upstream portion being positioned upstream of the return filter.

2. The liquid discharge head according to claim 1 , further comprising a supply filter provided in the supply channel.

3. The liquid discharge head according to claim 2 , further comprising a supply branching channel branching off from a supply upstream portion of the supply channel, the supply upstream portion being positioned upstream of the supply filter.

4. The liquid discharge head according to claim 3 , wherein the supply upstream portion extends in a first direction,
a first end in the first direction of the supply upstream portion is connected to the outlet of the storage chamber, and
a second end in the first direction of the supply upstream portion is connected to the supply branching channel.

5. The liquid discharge head according to claim 4 , wherein the return upstream portion extends in the first direction,
the return upstream portion and the supply upstream portion are arranged side by side in a second direction orthogonal to the first direction,
a first end in the first direction of the return upstream portion is farther away from the supply branching channel than a second end in the first direction of the return upstream portion, and
the first end in the first direction of the return upstream portion is connected to the return branching channel.

6. The liquid discharge head according to claim 5 , wherein a communicating portion communicating with the outlet of each of the individual channels is provided in an area ranging from the second end in the first direction of the return upstream portion to a center portion in the first direction of the return upstream portion.

7. The liquid discharge head according to claim 5 , wherein the return branching channel includes an extending portion extending in the first direction from the first end in the first direction of the return upstream portion,
a length in the second direction of the extending portion is equal to a length in the second direction of the first end of the return upstream portion, and
a length in a third direction, which is orthogonal to the first direction and the second direction, of the extending portion is equal to a length in the third direction of the first end of the return upstream portion.

8. The liquid discharge head according to claim 7 , wherein the third direction is a vertical direction,
the return branching channel includes the extending portion and a protrusion protruding upward from an upper end surface of the extending portion, and
a position in the vertical direction of the upper end surface of the extending portion is identical to a position in the vertical direction of the return filter.

9. The liquid discharge head according to claim 8 , wherein the return filter extends in the first direction to partially overlap in the vertical direction with the extending portion, and
a protrusion defining member defining a part of the protrusion positioned above the return filter is joined to the return filter at a portion overlapping in the vertical direction with the extending portion.

10. The liquid discharge head according to claim 9 , further comprising a filter plate having the return filter and joined to the protrusion defining member,
wherein the filter plate has a through hole forming the protrusion.

11. The liquid discharge head according to claim 1 , wherein a channel resistance of the return branching channel is larger than a channel resistance of a downstream portion of the return filter in the return channel.

12. The liquid discharge head according to claim 11 , wherein the channel resistance of the return branching channel is equal to a channel resistance of the return filter.

13. The liquid discharge head according to claim 1 , further comprising a valve switchable between a first position and second position,
wherein the valve in the first position allows the individual channels to communicate with the storage chamber via the return channel and does not allow the individual channels to communicate with the storage chamber via the return branching channel, and
the valve in the second position allows the individual channels to communicate with the storage chamber via the return branching channel and does not allow the individual channels to communicate with the storage chamber via the return channel.

14. The liquid discharge head according to claim 13 , wherein the valve is switchable to a third position,
the valve in the third position does not allow the individual channels to communicate with the storage chamber via the return branching channel and does not allow the individual channels to communicate with the storage chamber via the return channel.

15. The liquid discharge head according to claim 1 , wherein the return branching channel does not include the return filter.

16. A liquid discharge head, comprising:
a plurality of individual channels respectively including a plurality of nozzles;
a supply channel allowing an outlet of a storage chamber storing liquid to communicate with an inlet of each of the individual channels;
a return channel allowing an outlet of each of the individual channels to communicate with an inlet of the storage chamber;
a return filter provided in the return channel;
a return branching channel branching off from a return upstream portion of the return channel, the return upstream portion being positioned upstream of the return filter;
a valve switchable between a first position and a second position, the valve in the first position not allowing the individual channels to communicate with the return branching channel and allowing the individual channels to communicate with the storage chamber via the return channel, the valve in the second position not allowing the individual channels to communicate with the storage chamber via the return channel and allowing the individual channels to communicate with the return branching channel;
a pump; and
a controller,
wherein, in a bubble removal process, the controller is configured to execute a first process in which the liquid moves from the storage chamber to flow through the supply channel, each of the individual channels, the return upstream portion, and the return branching channel by driving the pump with the valve being in the second position.

17. The liquid discharge head according to claim 16 , further comprising:
a supply filter provided in the supply channel, and
a supply branching channel branching off from a supply upstream portion of the supply channel, the supply upstream portion being positioned upstream of the supply filter,
wherein the valve is switchable to a third position,
the valve in the third position does not allow the individual channels to communicate with the return branching channel and does not allow the individual channels to communicate with the storage chamber via the return channel, and
in the bubble removal process, the contro

Assignees

• Brother Ind Ltd

Inventors

• Hayashi Hideki

Classifications

• B41J2202/12

  with ink circulating through the whole print head · CPC title

• B41J2/161

  of film type, deformed by bending and disposed on a diaphragm · CPC title

• B41J2002/14241

  having a cover around the piezoelectric thin film element · CPC title

• B41J2/055

  Devices for absorbing or preventing back-pressure · CPC title

• B41J2002/14491

  Electrical connection · CPC title