JP2001232788A - Ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet head in which thermal conduction from a circuit board having a driving IC to a head chip unit having a head chip can be suppressed and thereby temperature elevation of the heat chip can be suppressed. SOLUTION: The ink jet head comprising a circuit board (1) having a driving IC (1A), and a head chip unit (2) having a head chip (2A) controlled by a signal from the driving IC (1A) is further provided with a first supporting base (3) for securing the circuit board 1 and a second supporting base (5) being connected with the first supporting base (3) through a thermal insulation member (4) and the head chip unit (2) is secured to the second supporting base (5).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet head provided in an ink jet type printer or the like, and more particularly, to a method for suppressing heat conduction from a circuit board having a driving IC to a head chip unit having a head chip. The present invention relates to an improved inkjet head.

FIG. 7 shows an example of a conventional structure of an ink jet head mounted on an ink jet printer or the like. This inkjet head uses a drive IC
(A1) and the driving IC (A).
Head chip (B1) controlled by a signal from 1)
And a support base (C) for fixing the circuit board (A) and the head chip unit (B). FIG.
The symbol (D) indicates an air damper.

The supporting base (C) is provided with a driving IC (A
It is formed in a plate shape from an aluminum alloy having high thermal conductivity so as to function as the heat sink of 1).
The circuit board (A) is bonded to the support base (C) via heat conductive silicon (not shown) so that the heat generated by the driving IC (A1) is quickly transferred to the support base (C). And fixed with screws.

Further, the head chip unit (B)
Are a nozzle plate (B2) bonded to the end face of the head chip (B1), and a nozzle cap (B3) fitted and bonded to the head chip (B1) so as to protect the nozzle plate (B2). An ink flow path member (B4) joined to the head chip (B1) to form an ink supply path to the head chip (B1);
1) having a signal electrode (B5) formed thereon. The head chip unit (B) includes a signal electrode (B
5) is positioned so as to be substantially flush with the circuit board (A) and to be connected to the signal line printed portion (A2) of the circuit board (A) via a flexible printed wiring (FPC). In this state, it is fixed to the support base (C) by a combination of bonding and screwing.

[0005]

By the way, in the structure of the conventional ink jet head shown in FIG. 7, the circuit board (A) is joined to the support base (C) via thermally conductive silicon, Since the head chip unit (B) is fixed to (C), when the drive IC (A1) on the circuit board (A) generates heat, the generated heat is transmitted to the head chip unit (B) via the support base (C). The temperature of the head chip (B1) rises significantly. For example, when the drive IC (A1) generates heat to about 80-C by passing a current of about 50 mA, the temperature of the support base (C) and the head chip unit (B) rises to about 60-C. As a result, the viscosity of the ink in the head chip (B1) is significantly reduced, the ejection speed of the ink ejected from each nozzle of the nozzle plate (B2) is increased, and ink scattering and ejection unevenness occur. is there.

Accordingly, an object of the present invention is to provide an ink jet head capable of suppressing heat conduction from a circuit board having a drive IC to a head chip unit having a head chip, and consequently suppressing an increase in the temperature of the head chip. And

[0007]

Means for Solving the Problems As means for solving the above-mentioned problems, an ink jet head according to a first aspect of the present invention comprises:
What is claimed is: 1. An inkjet head comprising: a circuit board having a drive IC; and a head chip unit having a head chip controlled by a signal from the drive IC, wherein a first support base for fixing the circuit board is provided. A second support base connected to the support base via a heat insulating member is provided, and the head chip unit is fixed to the second support base.

In the ink jet head according to the first aspect of the present invention, since the heat insulating member suppresses heat conduction from the first support base to the second support base, the heat insulating member moves from the circuit board having the drive IC to the head chip unit having the head chip. Heat conduction is suppressed, and the temperature rise of the head chip is suppressed.

An ink jet head according to a second aspect of the present invention is an ink jet head including a circuit board having a drive IC and a head chip unit having a head chip controlled by a signal from the drive IC. A first support base for fixing a circuit board, and a second support base made of a heat insulating material connected to the first support base are provided, and the head chip unit is fixed to the second support base. I do.

In the ink jet head according to the second invention, the second support base made of a heat insulating material suppresses heat conduction from the first support base to the head chip unit. The heat conduction to the head chip unit is suppressed, and the temperature rise of the head chip is suppressed.

In the first invention or the second invention, when the first support base is made of a metal material on which a plurality of radiating fins are formed, the conduction transmitted from the drive IC on the circuit board to the first support base. The heat can be efficiently radiated by the plurality of radiating fins, and the rise in the temperature of the head chip unit can be suppressed, and the decrease in the viscosity of the ink can be further suppressed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an ink jet head according to the present invention will be described below with reference to the drawings. In the drawings to be referred to, FIG. 1 is an exploded perspective view showing the entire structure of an inkjet head according to a first embodiment corresponding to the first invention. FIG. 2 is a side view of the ink jet head according to the first embodiment in an assembled state.

As shown in FIG. 1, the ink jet head according to the first embodiment has a circuit board (1) having a drive IC (1A) and a head chip (1) controlled by a signal from the drive IC (1A). 2A) having a head chip unit (2). The inkjet head has a first support base (3) for fixing the circuit board (1), and a second support base (5) connected to the first support base (3) via a heat insulating member (4). ) Are provided. The head chip unit (2) is fixed to the second support base (5).

The circuit board (1) has a thickness of 0.8 to 1.6.
mm, a plurality of output signal lines (1B) for outputting a drive signal from the drive IC (1A) are printed on the near side in FIG. 1 (the lower edge side in FIG. 2). The circuit board (1) is provided with each drive IC.
(1A) is bonded to the first support base (3) via the thermally conductive silicon (6) so as to quickly transfer the heat generated to the first support base (3) (see FIG. 2); And,
It is fixed to the first support base (3) by a set screw (7) (see FIG. 1).

The head chip unit (2) includes a nozzle plate (2) bonded to an end face of the head chip (2A).
B), a nozzle cap (2C) fitted and bonded to the head chip (2A) so as to protect the nozzle plate (2B), and a head chip (2A) bonded and fixed to the head chip (2A). And an ink flow path member (2D) that forms an ink supply path to the ink passage. A flexible printed wiring (F) is provided on the head chip (2A).
A signal electrode (2E) for inputting a drive signal via the PC is formed by vapor deposition.

The head chip (2A) has a structure in which a similar piezoelectric ceramic cover plate (2A2) is joined to a piezoelectric ceramic actuator plate (2A1). Actuator plate (2A1)
Has a plurality of channels (not shown) forming an ink ejection passage formed in parallel, and an electrode (to which an electric field signal from the driving IC (1A) is applied) is provided on each side wall partitioning each channel. (Not shown) are formed. The cover plate (2A2) is formed with a common ink chamber (not shown) communicating with each channel of the actuator plate (2A1). Then, when the electric field signal from the drive IC (1A) of the circuit board (1) is applied to the electrodes of the actuator plate (2A1), the ink in the corresponding channel reduces the drive pressure. It is configured to be pushed out toward the nozzle plate (2B) side.

The nozzle plate (2B) has a polyimide film or the like as a base film, and a water-repellent film having a water-repellent property is laminated on a surface of the nozzle plate (2B) in order to prevent the adhesion of ink. And this nozzle plate (2B)
A plurality of ink ejection holes (not shown) corresponding to the openings of each channel of the head chip (2A) are formed using an excimer laser device or the like.

The nozzle cap (2C) is integrally formed of an appropriate metal or synthetic resin having high wear resistance. The nozzle cap (2C) is fitted to the head chip (2A) and the nozzle plate (2C).
An opening (2C1) surrounding the periphery of B) is formed. Further, a pair of left and right flange pieces (2D1) fixed to the second support base (5) via set screws (8) are integrally formed of a synthetic resin on the ink flow path member (2D). . An ink introduction pipe (2D2) is attached to the ink flow path member (2D).

The signal electrode (2E) is disposed behind the cover plate (2A2) of the head chip (2A) and is deposited on the actuator plate (2A1). Each signal line of the signal electrode (2E) is connected to each output signal line (1B) of the circuit board (1) via a flexible printed wiring (FPC). For this reason, the head chip unit (2) includes the actuator plate (2).
The signal electrode (2E) of A1) and each output signal line (1B) of the circuit board (1) are fixed to the second support base (5) in a state where they are aligned.

The first support base (3) is provided with a driving IC (1).
It is formed in a plate shape from an aluminum alloy having high heat conduction efficiency so as to function as the heat sink of A). The first support base (3) has a screw hole (3A) for fixing the support arm (9A) of the air damper (9) with a set screw (10). As shown in FIG. 2, a plurality of radiation fins (3B) are formed on the back surface of the first support base (3). And the first
At the lower part of the support base (3), a pair of left and right connection pieces (3C) with the second support base (5) are protruded in a state of being offset to the back side, and each connection piece (3C) has a screw. Insertion holes (3D) are respectively formed (see FIG. 3).

The heat insulating member (4) is made of a suitable synthetic resin having a high heat insulating property, and as shown in FIGS. 1 and 3, is superposed on the connection piece (3C) from the surface side of the first support base (3). It is formed in small pieces. The heat insulating member (4) has a screw insertion hole (3D) for the connection piece (3C).
Is formed.

The second support base (5) is integrally formed of an aluminum alloy having high heat conduction efficiency similarly to the first support base (3). This second support base (5)
The support base (5) connected to the pair of connection pieces (3C) of the first support base (3) via the pair of heat insulating members (4).
A), a pair of mounting bases (5B) extending orthogonally from both ends of the support base (5A), and a corner between the inside of each mounting base (5B) and the support base (5A). And a pair of flange receiving pieces (5C) protruding toward the front side of the support base (5A).

The support base (5A) is placed on the heat insulating member (4) such that the surface thereof is substantially flush with the surface of the first support base (3). Then, as shown in FIG. 3, the connecting piece (3C) is provided on the support base (5A).
A pair of screw insertion holes (5D) corresponding to the respective screw insertion holes (3D) are formed. Also, as shown in FIG.
The flange piece (2D1) of the ink flow path member (2D) is fixed to the flange receiving piece (5C) with a set screw (8).

FIG. 3 shows a connecting piece (3C) of the first support base (3) and a support base (5A) of the second support base (5).
And a structure in which they are connected via a heat insulating member (4). In this connection structure, from the support base (5A) side, through the screw insertion hole (5D), the screw insertion hole (4A) of the heat insulating member (4), and the screw (3D) of the connection piece (3C), the connection screw (3D) is inserted. 11) is inserted, and the heat insulating sleeve (12) is inserted into the screw insertion hole (3D) of the connection piece (3C) from the tip side of the connection screw (11). This insulation sleeve (1
2) is made of the same synthetic resin as the heat insulating member (4), and has a brim (12A) that comes into contact with the connecting piece (3C). Then, a nut (13) is screwed into the tip of the connection screw (11) so that the connection piece (3C) is tightened through the collar (12A).

The nut (13) is connected to the connecting piece (3).
This can be omitted by changing the screw insertion hole (3D) in (C) to a female screw hole (3E) as shown in FIG. In this case, the heat insulating sleeve (12) is inserted into the screw insertion hole (5D) from the front side of the support base (5A). Then, the connection screw (11) is inserted into the screw insertion hole (5D) of the support base (5A) and the screw insertion hole (4A) of the heat insulating member (4) via the heat insulating sleeve (12). Into the female screw hole (3E) of the connection piece (3C).

In the ink jet head of the first embodiment configured as described above, during operation, each drive IC (1A) on the circuit board (1) is set at 20 to 30 V, 50 m.
A drive signal of about A is output, and at that time, heat is generated to about 80-C. Then, the heat generated by each drive IC (1A) is quickly transmitted to the first support base (3) through the heat conductive silicon (6).
And the heat is dissipated from each of the heat dissipating fins (3B) on the back side. For this reason, the temperature rise of the first support base (3) is suppressed to 60-C or less, for example, about 50-C. Moreover, since each of the heat insulating members (4) and the heat insulating sleeve (12) suppresses heat conduction from the first support base (3) to the second support base (5), the second support base (5) and the head chip unit are formed. The temperature rise in (2) is suppressed to 40 ° or less. As a result, a significant decrease in the viscosity of the ink passing through each channel of the head chip (2A) is suppressed.
Therefore, according to the ink jet head of the first embodiment, it is possible to solve the problem that the ejection speed of the ink ejected from the ink ejection holes of the nozzle plate (2B) is increased to cause ink scattering or uneven ejection. Can be.

Next, an ink jet head according to a second embodiment corresponding to the first invention will be described. As shown in FIG. 5, the ink jet head of the second embodiment has a first support base (23) having a lower part formed in a flat plate shape, and the first support base (23).
A heat insulating member (24) formed in a U-shaped cross section sandwiching the lower portion of the support base (23), and a pair of support bases (25A) sandwiching the heat insulating member (24) include an attachment base (25).
B) and a second support base (25) formed orthogonal to B). In the ink jet head according to the second embodiment, a structural portion (not shown) is configured in the same manner as the ink jet head according to the first embodiment described above, and thus detailed description is omitted.

The first support base (23) corresponds to the above-mentioned first support base (3), and has a lower portion provided with a screw similar to the screw insertion hole (3D) of the first support base (3). A pair of left and right insertion holes (23D) is formed. The heat insulating member (24) corresponds to the above-described heat insulating member (4),
Screw insertion hole (24A) similar to the screw insertion hole (4A)
Are formed. And the second support base (25)
Corresponds to the above-mentioned second support base (5). A screw insertion hole (25D) similar to the screw insertion hole (5D) is formed in one support base (25A), and the other support base is formed. A female screw hole (25E) is formed in (25A).

In the ink jet head of the second embodiment, the screw insertion hole (2) of one support base (25A) is provided.
5D) to the screw insertion hole (24A) of the heat insulating member (24),
The connection screw (11) is inserted through the screw insertion hole (23D) of the first support base (23) and the screw insertion hole (24A) of the heat insulating member (24). And connection screw (11)
Is screwed into the female screw hole (25E) of the other support base (25A), whereby the lower portion of the first support base (23) and the support base (25A) of the second support base (25) are connected. It is connected via a heat insulating member (24).

In the ink jet head of the second embodiment having the above-described structure, the heat insulating member (24) suppresses heat conduction from the first support base (23) to the second support base (25). The temperature rise of the second support base (25) and the head chip unit (not shown) fixed thereto is suppressed to 40 ° or less. Therefore, also in the ink jet head of the second embodiment, the same operation and effect as those of the ink jet head of the first embodiment can be obtained.

Next, an ink jet head according to a third embodiment corresponding to the second invention will be described. As shown in FIG. 6, the ink jet head of the third embodiment has a first support base (3) of the ink jet head of the first embodiment.
A first support base (33) configured in the same manner as described above, and a second support base (35) formed of a suitable heat-insulating synthetic resin into a shape similar to that of the second support base (5), Members corresponding to the heat insulating member (4) are omitted.
In the ink jet head according to the third embodiment, a structural portion (not shown) is configured in the same manner as the ink jet head according to the first embodiment described above, and thus detailed description is omitted.

At the lower part of the first support base (33), a connecting piece (33C) corresponding to the above-mentioned connecting piece (3C) is projected, and the connecting piece (33C) is provided with the above-mentioned screw insertion hole ( 3
A pair of left and right screw insertion holes (33D) similar to D) are formed. The second support base (35) has a support base (35A) and a mounting base (35B) corresponding to the above-described support base (5A) and mounting base (5B). Screw insertion hole (5
A screw insertion hole (35D) similar to D) is formed.

In the ink jet head of the third embodiment, for example, the connection screw (11) is inserted from the connection piece (33C) side through the screw insertion hole (33D) and the screw insertion hole (35D) of the support base (35A). You. Then, the nut (13) is screwed into the distal end of the connection screw (11), so that the connection piece (33C) of the first support base (33) and the support base (3) of the second support base (35).
5A) is connected. Note that the connection screw (11) may be inserted from the support base (35A) side to the connection piece (33C) side, and the nut (13) may be screwed to the tip end.

In the ink jet head according to the third embodiment having the above-described structure, the second support base (35) formed of an appropriate synthetic resin having high heat insulation is used as the first support base (35).
In order to suppress heat conduction from the support base (33) to the head chip unit (not shown) fixed to the second support base (35), the temperature rise of the head chip unit (not shown) is suppressed to 40 ° or less. You. Therefore, also in the ink jet head of the third embodiment, the same operation and effect as those of the ink jet head of the first embodiment or the second embodiment can be obtained.

[0035]

As described above, according to the ink jet head of the first aspect, the heat insulating member suppresses heat conduction from the first support base to the second support base. Heat conduction to the head chip unit having the head chip can be suppressed, and the temperature rise of the head chip can be suppressed. Therefore, it is possible to prevent a decrease in the viscosity of the ink in the head chip, and to eliminate inconveniences such as scattering of ink ejected from the nozzle plate and uneven ejection.

Further, according to the ink jet head of the second aspect, the second support base made of a heat insulating material is the first support base.
In order to suppress heat conduction from the support base to the head chip unit, it is possible to suppress heat conduction from the circuit board having the drive IC to the head chip unit having the head chip,
The temperature rise of the head chip can be suppressed. Therefore, it is possible to prevent a decrease in the viscosity of the ink in the head chip, and to eliminate inconveniences such as scattering of ink ejected from the nozzle plate and uneven ejection.

In the ink jet head according to the first or second aspect of the present invention, when the first supporting base is made of a metal material having a plurality of radiating fins, the first supporting base is connected to the driving IC on the circuit board. The conduction heat transmitted to the member can be efficiently radiated by the plurality of radiating fins, and the heat conduction to the head chip unit side can be further suppressed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing the entire structure of an inkjet head according to a first embodiment corresponding to the first invention.

FIG. 2 is a side view of the ink jet head according to the first embodiment in an assembled state.

FIG. 3 is an enlarged sectional view of a main part in an assembled state of the ink jet head according to the first embodiment.

FIG. 4 is an enlarged sectional view of a modification of the main part shown in FIG. 3;

FIG. 5 is an enlarged sectional view of a main part in an assembled state of an ink jet head according to a second embodiment corresponding to the first invention.

FIG. 6 is an enlarged sectional view of a main part in an assembled state of an ink jet head according to a third embodiment corresponding to the second invention.

FIG. 7 is an exploded perspective view showing the entire structure of an ink jet head according to a conventional example.

[Explanation of symbols]

 1: Circuit board 1A: Drive IC 1B: Output signal line 2: Head chip unit 2A: Head chip 2B: Nozzle plate 2C: Nozzle cap 2D: Ink channel member 2E: Signal line printed board 3: First support base 3A: Screw hole 3B: Radiation fin 3C: Connection piece 3D: Screw insertion hole 3E: Female screw hole 4: Heat insulation member 4A: Screw insertion hole 5: Second support base 5A: Support base 5B: Mounting base 5C: Flange receiving piece 5D: Screw Insertion hole 6: Thermal conductive silicon 7: Set screw 8: Set screw 9: Air damper 10: Set screw 11: Connection screw 12: Heat insulation sleeve 13: Nut

Claims (3)

[Claims] 1. An ink jet head comprising: a circuit board having a drive IC; and a head chip unit having a head chip controlled by a signal from the drive IC, wherein the first support base fixes the circuit board. When,
The second support base is connected to the first support base via a heat insulating member.
An ink jet head comprising: a support base; and the head chip unit fixed to the second support base. 2. An ink jet head comprising: a circuit board having a drive IC; and a head chip unit having a head chip controlled by a signal from the drive IC, wherein the first support base fixes the circuit board. When,
An ink jet head comprising: a second support base made of a heat-insulating material connected to the first support base; and the head chip unit fixed to the second support base. 3. The ink jet head according to claim 1, wherein the first support base is made of a metal material having a plurality of radiation fins formed thereon. .