Liquid ejection head and liquid ejection apparatus

Patent metadata

Field	Value
Publication number	US-9254658-B2
Application number	US-201314397938-A
Country	US
Kind code	B2
Filing date	May 31, 2013
Priority date	Jun 18, 2012
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

A liquid ejection head includes, a first support member including a flow path for supplying liquid and an opening communicating with the flow path; at least one second support member that includes an individual liquid chamber communicating with the opening and arranged on the first support member along the flow path; and a recording element substrate including an energy-generating element for generating energy for ejecting the liquid, and a supply port for supplying the liquid to the energy-generating element, the supply port communicating with the individual liquid chamber, the recording element substrate being supported by a back surface of the second support member with respect to an opposite surface thereof facing the first support member. When P (μJ/pL) represents energy to be input per ejection liquid droplet volume in the energy-generating element, thermal resistance R (K/W) of a shortest heat transfer path of the second support member between the recording element substrate and the first support member satisfies:

R ≧ 1.4 / ln{0.525e 1.004P − 0.372 } −1 .

First claim

The invention claimed is:

1. A liquid ejection head, comprising:
a first support member including a flow path for supplying liquid and an opening communicating with the flow path;
at least one second support member including an individual liquid chamber communicating with the opening, the at least one second support member being arranged on the first support member along the flow path; and
a recording element substrate including an energy-generating element for generating energy to be used for ejecting the liquid, and a supply port for supplying the liquid to the energy-generating element, the supply port communicating with the individual liquid chamber, the recording element substrate being supported by a back surface of the at least one second support member with respect to an opposite surface thereof facing the first support member, wherein when energy to be input per ejection liquid droplet volume in the energy-generating element is defined as P (μJ/pL), a thermal resistance R (K/W) of a shortest heat transfer path of the at least one second support member between the recording element substrate and the first support member satisfies the following expression:
R≧ 1.4/ln{0.525 e 1.004P −0.372} −1 .

2. A liquid ejection head according to claim 1 , wherein the first support member comprises an inflow port for allowing the liquid to flow into the flow path and an outflow port for allowing the liquid to flow out from the flow path, and the liquid having flown out from the outflow port flows into the inflow port through a circulation path provided outside of the liquid ejection head.

3. A liquid ejection head according to claim 1 , wherein a plurality of the second support members are arranged in a longer direction of the first support member.

4. A liquid ejection head according to claim 1 , wherein the flow path extends so as to meander in a longer direction of the first support member.

5. A liquid ejection head according to claim 1 , wherein, when the energy-generating element is driven at a drive frequency of 1.8 kHz or less, a ratio Q/Q′ between ejection energy per unit time Q to be applied from the energy-generating element to the liquid and a heat discharge per unit time Q′ to be transferred from the energy-generating element as a generation source to the first support member is 5.1 or more.

6. A liquid ejection head according to claim 2 , wherein a heat discharge per unit time Q′ to be transferred from the energy-generating element as a generation source to the first support member during driving under maximum load regarding all the recording element substrates is determined by the following expression:

Q
′

=

(

Δ
⁢

⁢

Vd
/
Vd

)

·
Cp

(

C
/
100

)

·

∑

n
=
1

N

⁢

⁢

(

F
+

f
⁡

(

N
-
n
+
1

)

)

-
1

where Vd represents an ejection amount per ejection operation from one ejection orifice (ng);
C represents a temperature coefficient of Vd (%/K);
ΔVd represents a deviation of Vd causing visually recognizable unevenness (ng);
Cp represents a specific heat of the liquid (W/g/K);
F represents a flow rate of the liquid at an exit of the flow path (g/s);
f represents an ejection amount per recording element substrate during driving under maximum load (g/s); and
N represents a total number of the recording element substrates.

7. A liquid ejection head according to claim 1 , wherein the thermal resistance R of the at least one second support member in both end portions of the liquid ejection head in a longer direction of the liquid ejection head is larger than the thermal resistance R of the at least one second support member in a center portion of the liquid ejection head in the longer direction of the liquid ejection head.

8. A liquid ejection head according to claim 1 , wherein the at least one second support member contains a space portion partitioned from the individual liquid chamber.

9. A liquid ejection head according to claim 1 , wherein the individual liquid chamber provided in the at least one second support member has a width of 3 mm or more in an array direction in which ejection orifices for ejecting the liquid are arranged.

10. A liquid ejection head according to claim 1 , wherein the individual liquid chamber provided in the at least one second support member has a width of 3 mm or more in a paper conveyance direction.

11. A liquid ejection head according to claim 1 , further comprising a terminal support positioned adjacent to the at least one second support member on the first support member, wherein the terminal support supports a lead terminal electrically connected to a signal input electrode of the recording element substrate and has a modulus of elasticity higher than a modulus of elasticity of the at least one second support member.

12. A liquid ejection apparatus, comprising:
the liquid ejection head according to claim 1 ; and
a cooler for cooling the liquid supplied to the flow path.

13. A liquid ejection head, comprising:
a first support member including a flow path for supplying liquid and multiple openings communicating with the flow path;
at least one second support member arranged on the first support member; and
multiple recording element substrates each including an energy-generating element for generating energy to be used for ejecting the liquid, the multiple recording element substrates being arranged on a back surface of the at least one second support member with respect to a surface thereof on which the first support member is arranged,
wherein when energy to be input per ejec

Assignees

• Canon Kk

Inventors

• Yamada Kazuhiro
• Iwanaga Shuzo
• Goto Ryohei
• Moriya Takatsugu
• Tamenaga Zentaro

Classifications

• B41J2/155 Primary

  for line printing · CPC title

• B41J2202/20

  Modules · CPC title

• B41J29/02

  Framework · CPC title

• B41J2202/12

  with ink circulating through the whole print head · CPC title

• B41J2/14427 Primary

  Structure of ink jet print heads with thermal bend detached actuators · CPC title