JP3244946B2 - Inkjet head - Google Patents

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, and more particularly to a head of an ink jet recording apparatus.

[0002]

2. Description of the Related Art Known documents describing conventional ink jet heads include, for example, Japanese Patent Publication No. Sho 62-596.
No. 72 publication. According to this publication, a lid member is provided on an ink flow channel of a base on which an active element for discharging liquid is provided along an ink flow channel formed of a cured layer of a photosensitive resin. This is to form an ink flow path.

Japanese Patent Application Laid-Open No. 4-185444 discloses an ink jet head which pressurizes ink in an ink flow path and ejects ink droplets, wherein the ink flow path has one surface having a piezoelectric element, The other surface facing the surface and a side wall interposed between the two surfaces to form the ink flow path, the side wall being integrally formed with a lid plate forming the other surface; The side wall is formed of a photosensitive resin on a lid plate. That is,
The ink passage groove is formed on the lid member.

[0004]

In the liquid chamber of the ink jet head, ensuring the bonding strength of the liquid chamber forming member is a very important characteristic item for maintaining reliability and performance. If the intensity is not obtained, a leak occurs between the channels, and when a plurality of channels are driven simultaneously, the speed of the ink droplets is lower than when driven alone, and the image quality is disturbed. Further, if the ink leaks from the liquid chamber due to insufficient strength and the ink comes into contact with the actuator, and the driving efficiency of the actuator is reduced, or if the actuator is in an even worse state, safety such as heat generation and smoking is impaired.

Further, if there is a large difference in the area ratio between the resin-formed portion and the non-formed portion on the substrate, there is a problem that the substrate is warped due to shrinkage due to joining. As a result, the connection with the ink supply pipe cannot be obtained, and problems such as leakage of ink occur.

In the above-mentioned Japanese Patent Publication No. 62-59672, the common liquid chamber is not shown, so that no remarkable phenomenon is observed. However, unlike the common liquid chamber, the photosensitive resin does not exist. Then, contraction deformation occurs at the time of joining.
In addition, if the photosensitive resin is provided only on the side where the active element is provided, cracks may occur at the interface due to bonding, or peeling of the photosensitive resin may occur.

Further, the above-mentioned Japanese Patent Application Laid-Open No. 4-185444
In the publication, after forming a flow path with a photosensitive resin on a lid member, the flow path is joined to an active element and integrated with a head. Also in this case, since there is a resin member on one side,
Stress occurs at the time of joining, and the internal stress after joining causes peeling and cracking. In addition, since there is no column, the stress of the internal pressure acts greatly on the common liquid chamber, causing peeling and leakage to the outside.

The present invention has been made in view of such circumstances. By forming a flow path on both substrates, the resin is not concentrated on one of the substrates. To prevent the occurrence of peeling,
It is an object of the present invention to provide an ink jet head that maintains the flatness and bonding strength by providing a column in the common liquid chamber and increases the resistance to internal pressure of the head.

[0009]

In order to achieve the above object, the present invention provides: (1) a liquid chamber portion comprising a nozzle plate having a plurality of nozzles and a diaphragm; And an on-demand type ink jet head in which liquid chambers are formed of a photosensitive resin on the vibration plate and joined by temperature and pressure, respectively, wherein the liquid chambers are provided corresponding to each actuator. and a pressurized liquid chamber section, Ri Do from the common liquid chamber to be distributed to the pressurized liquid chamber portion, the said common liquid chamber and the nozzle plate at a position separated from the pressure chamber portion and the outer wall Shake
A pillar where the photosensitive resin formed on the moving plate is joined and integrated
And (2) the odor described in (1) above.
And (3) the column is formed in the same shape at the joining interface.
Te, the shape of the pillars, the length the liquid flow direction in the flow direction, it has a long shape than the length in the direction Cartesian flow, further, (4) the (1), (2) or
In (3), a plurality of the columns are arranged in the common liquid chamber, and further (5) the (1), (2),
(3) or (4), wherein the columns are made of the same photosensitive resin and are formed on the vibration plate and the nozzle plate at the same time when the liquid chamber is formed.

[0010]

In the ink jet head of the present invention, the liquid chamber portion includes a nozzle plate and a vibrating plate, and the liquid chambers are formed of a photosensitive resin on the nozzle plate and the vibrating plate, respectively, and both are joined by temperature and pressure. to an on-demand type ink jet head integrated, (1) the photosensitive resin formed on the vibration plate and the nozzle plate on are formed with the same kind of photosensitive resin, the flow path portion both substrates In this case, the resin is not concentrated on one side, and cracks and peeling due to curing shrinkage due to heat bonding can be prevented. The liquid chamber is composed of a pressurized liquid chamber portion provided corresponding to each actuator, and a common liquid chamber portion distributed to the pressurized liquid chamber portion. Since the column is provided at a position separated from the wall, by providing the column in the common liquid chamber portion, flatness and bonding strength are maintained, and resistance to the internal pressure of the head is increased. (2) Since the pillars are formed in the same shape at the joint interface, by making the pillar portions the same shape, the ink flow flowing in the liquid chamber becomes smooth, so that a large amount of ink is printed when printing at high speed. Of ink is required, but ink can be supplied to the pressurized chamber.
(3) The shape of the column is such that the length in the flow direction is longer than the length in the direction perpendicular to the flow with respect to the flow direction of the liquid. Thereby, the flow of the supply liquid chamber becomes smooth. (4) Since the plurality of columns are arranged in the common liquid chamber, providing a plurality of columns prevents stress concentration at one location and maintains flatness. (5) Since the columns are made of the same photosensitive resin and are formed simultaneously on the vibration plate and the nozzle plate when the liquid chamber is formed, the process can be simplified.

[0011]

Embodiments will be described below with reference to the drawings. FIGS. 1A and 1B are configuration diagrams for explaining an embodiment of an ink jet head according to the present invention.
1A is a sectional view, and FIG. 1B is an exploded view of a liquid chamber.
In the figure, 1 is a liquid chamber part, 2 is an actuating part, 3 is a substrate,
4 is a piezoelectric element, 5 is a diaphragm, and 6 and 7 are photosensitive resins (DF
R), 8 is a nozzle plate, 9 is a nozzle, 10 is a pressurized liquid chamber, 1
1 is a common liquid chamber, and 12 is an ink supply port. The ink jet head according to the present invention includes an actuator section 2 and a liquid chamber section 1.
It is composed of The liquid chamber section 1 is composed of a nozzle plate 8 and a vibration plate 5, and a pressurizing chamber 10 is provided so as to correspond to each nozzle 9.

First, the invention according to claims 1 to 4 will be described. The liquid chamber is made of nozzle plate, diaphragm and photosensitive resin
At the time of formation, two divided surfaces are conceivable, that is , a bonding interface is made of one substrate and a photosensitive resin or a photosensitive resin formed on a vibration plate and a nozzle plate. In terms of the process, lamination on one substrate surface can be simplified. However, by patterning on each substrate (vibrating plate and nozzle plate), the stress is divided into two by the formation of the resin, and the deformation of the substrate is reduced. Therefore, as shown in the embodiment, the surface of the nozzle plate 8 has D
By providing the DFR 6 on the surface of the FR 7 and the diaphragm 5, the stress balance between the two is maintained.

Also, a photosensitive resin (DFR) used for both.
By setting the thickness ratio of 6, 7 to 1 to 3, the contraction balance at the time of joining is maintained, and a liquid chamber flow path without deformation is obtained.
At this time, if the substrate material is different, it is preferable to form the pattern using a photosensitive resin suitable for each. From the viewpoint of bonding strength, if the same type of photosensitive resin is not used, cracks occur due to a difference in expansion coefficient when heated, and the resin is peeled off from the substrate.

As described above, the photosensitive resin formed on the vibration plate and the nozzle plate is formed of the same kind of photosensitive resin, and the thickness ratio of the photosensitive resin film is 1 to 3. Since the flow path is formed on both substrates, the resin is not concentrated on one side, and cracks and peeling due to curing shrinkage due to heat bonding can be prevented.

FIG . 2 is a plan view of the liquid chamber portion. In the drawing, reference numeral 20 denotes a column, and other portions having the same function as in FIG. 1 are denoted by the same reference numerals. The liquid chamber section 1 includes a common liquid chamber 11 and a pressurized liquid chamber 10.
It is composed of The common liquid chamber 11 is patterned and formed on each substrate with a member equivalent to a photosensitive resin forming other liquid chambers (outer walls 6, 7 and pressurized liquid chamber 10).

As described above, the liquid chamber comprises the pressurized liquid chamber provided for each actuator and the common liquid chamber distributed to the pressurized liquid chamber. Since the column is provided at a position separated from the pressurizing chamber and the outer wall, flatness and bonding strength are maintained by providing the column in the common liquid chamber,
The head is more resistant to internal pressure. In addition, since the columns are formed in the same shape at the joint interface, by making the shapes of the column portions the same, the flow of the ink flowing in the liquid chamber becomes smooth, whereby a large amount of ink is printed when printing at high speed. Although ink is required, ink can be supplied to the pressure chamber.

3 (a) and 3 (b) are diagrams showing the shape of the pillar portion. FIG. 3 (a) is a streamline shape, and FIG. 3 (b) is an egg shape. The basic shape of the shape is such that the length L in the downstream direction with respect to the direction in which the liquid flows, that is, the ink supply port, is longer than the length M in the direction perpendicular to the flow. In addition, no corners are provided so that the ink flows smoothly. A streamline shape (Fig. (A)) or an egg shape (Fig. (B)) as shown in the embodiment is desirable.

As described above, the shape of the column is such that the length in the flow direction is longer than the length in the direction perpendicular to the flow with respect to the flow direction of the liquid. The flow of the supply liquid chamber becomes smooth by adopting a shape that does not become flat.

When the number of pillars is not one large one but a plurality of smaller ones are dispersed and arranged in the common liquid chamber 11, the stress is dispersed and the flow resistance is reduced. Therefore, a distributed arrangement is desirable. Further, since a force acts in a direction in which the photosensitive resin is peeled off by the internal pressure, a peeling strength is further increased if there is a large area without pillars. As described above, since the plurality of columns are arranged in the common liquid chamber, by providing a plurality of columns, concentration of stress at one location can be prevented and planarity can be maintained.

FIGS. 4 (a) and 4 (b) are views showing the joined state with and without a pillar in the common liquid chamber.
It is A sectional drawing. FIG. 4A shows a case without pillars, and FIG.
(B) is a case where there is a pillar. In the figure, 30 is an adhesive,
In addition, the portions having the same functions as those in FIG. 1 are denoted by the same reference numerals. As shown in FIG. 4 (a), when there is no pillar, a member is pressed at the time of joining, and the rigidity of the substrate is lower due to the curing shrinkage of the resin (a diaphragm is shown in this example).
Is deformed. The deformation amount δ at this time differs depending on the temperature, the pressing force, and the conditions of the jig. Due to this deformation, bonding with the piezoelectric (active) element 4 cannot be obtained, and the performance efficiency of the piezoelectric element decreases. In the worst case, the piezoelectric element 4
In some cases, it does not adhere and does not function.

In the embodiment, only the active element portion is shown. However, even when the ink supply port is connected, the ink supply pipe is not connected to the ink supply port 12 provided in the diaphragm 5, so that the ink leaks. Cause it to do so.
As shown in FIG. 4 (b), a case where there is a pillar is shown. However, according to the present invention, deformation can be prevented, and the above-described problem is improved.

Next, the invention according to claim 5 will be described. The pillars provided in the common liquid chamber 11 form a pattern with the same type of photosensitive resin by using a photolithography process together when forming the flow path. Thereby, the joining can be performed under the same conditions as the joining of the flow path portion, and the shrinkage rate becomes constant, so that the flatness can be maintained. As described above, since the columns are formed of the same photosensitive resin on the vibration plate and the nozzle plate at the same time when the liquid chamber is formed, the process can be simplified.

[0023]

【The invention's effect】

(1) Effect corresponding to claim 1 : By forming the flow path portion on both substrates, the resin is not concentrated on one side, and cracks and peeling due to curing shrinkage due to heat bonding can be prevented. In addition, by providing a column in the common liquid chamber,
And the joint strength is maintained. This allows the inside of the head
Increased resistance to pressure. (2) Effect corresponding to the second aspect : By making the shape of the pillar portions the same, the flow of ink flowing in the liquid chamber becomes smooth. Thus, a large amount of ink is required for high-speed printing, but ink can be supplied to the pressure chamber. (3) Effect corresponding to claim 3 : The flow of the supply liquid chamber becomes smooth by making the column shape a shape that does not cause flow resistance. (4) Effect corresponding to claim 4 : By providing a plurality of pillars, stress concentration at one location can be prevented and planarity can be maintained. (5) Effect corresponding to claim 5 : The process can be simplified by forming the column portion with the same photosensitive resin as the liquid chamber forming member.

[Brief description of the drawings]

FIG. 1 is a configuration diagram for explaining an embodiment of an inkjet head according to the present invention.

FIG. 2 is a plan view of a liquid chamber in the present invention.

FIG. 3 is a view showing a shape of a pillar in the present invention.

FIG. 4 is a sectional view taken along the line AA in FIG. 2, showing a joined state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Liquid chamber part, 2 ... Actuate part, 3 ... Substrate, 4 ... Piezoelectric element, 5 ... Vibration plate, 6, 7 ... Photosensitive resin (DFR),
8 ... Nozzle plate, 9 ... Nozzle, 10 ... Pressurized liquid chamber, 11 ... Common liquid chamber, 12 ... Ink supply port, 20 ... Column, 30 ... Adhesive.

Continued on the front page (72) Michio Umezawa, Inventor Ricoh, 1-3-6 Nakamagome, Ota-ku, Tokyo (72) Inventor Tetsuro Hirota 1-3-6, Nakamagome, Ota-ku, Tokyo, Ltd. Inside Ricoh (72) Inventor Shuzo Matsumoto 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Hideyuki Makita 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Tsutomu Sasaki 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72) Inventor Yoshihisa Ota 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Company (72 ) Inventor Taeko Murai 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-6-122196 (JP, A) JP-A-6-84222 (JP, A) JP-A-2-84340 (JP, A) JP-A-64-45650 (JP, A) JP-A-5-28638 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB Name) B41J 2/045 B41J 2/055 B41J 2/16

Claims (5)

(57) [Claims] 1. A liquid chamber portion includes a nozzle plate having a plurality of nozzles and a vibration plate, and a liquid chamber is formed of a photosensitive resin on each of the nozzle plate and the vibration plate, and both are joined by temperature and pressure. in the on-demand type ink jet head integrated with, it from the liquid chamber portion, and a pressurized liquid chamber which is provided corresponding to each actuator, and a common liquid chamber to be distributed to the pressurized liquid chamber portion The common liquid chamber is formed on the nozzle plate and the diaphragm at a position separated from the pressure chamber and the outer wall.
An ink jet head comprising a pillar formed by joining photosensitive resins together . 2. An ink jet head according to claim 1, characterized in that said post is formed in the same shape at the bonding interface. The shape of claim 3, wherein the pillar, the flow direction of the length of the flow direction liquid, according to claim 1, wherein it is in the shape longer than the length in the direction perpendicular to the flow Inkjet head. 4. The method of claim 1 to 3 inkjet head according to any one, characterized in that said post is a plurality disposed in said common liquid chamber. Wherein said post is at the same photosensitive resin, according to claim 1 to 4 inkjet head according to any one, characterized in that it is formed simultaneously with the liquid chamber formed in the diaphragm and the nozzle plate.