JP2001179977A - Ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means capable of achieving an enhanced adhesion between a substrate having resistive heating elements and a fluid passage groove in an ink jet head 10 and even in a black head unit having a black orifice row. SOLUTION: The ink jet head 10 comprises a top plate 1 which is so constituted that two parallel orifice rows of, for example, a photo color ink orifice row 23 and a color ink orifice row 24 and a supplying hole group for supplying each ink to the respective orifices are integrally formed thereon and an elastic member such as a plate spring 25 provided to a recessed section 6 disposed between two orifice rows. A cutout 28 is provided at a weight acting point of the plate spring 25 as the elastic member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet recording head used in an ink jet recording apparatus.

[0002]

2. Description of the Related Art Heretofore, as an energy generating element for ejecting ink droplets of an ink jet recording apparatus of this type, an element using an electromechanical transducer such as a piezo element, or irradiating an electromagnetic wave such as a laser to generate heat has been used. And a method in which a liquid is heated by an electrothermal conversion element having a heating resistor.

In this type of ink jet recording apparatus, a recording head for ejecting a plurality of different types of liquids (inks) through two orifice rows has been proposed in response to demands for high image quality / high speed printing performance.

FIG. 10 shows a perspective view of an example of a conventional recording head. In FIG. 10, reference numeral 10 denotes an ink jet recording head, 1 is a top plate provided with a liquid flow channel, a liquid chamber, and an orifice row, and 2 is an electric board for mounting a resistance heating element and a carriage. The wiring board 3 is connected to an elastic body that presses and fixes the substrate 2 having the heating element against the top plate 1, and the reference numerals 23 and 24 are perforated in the top plate 1 and the photo color inks (y, m, c) and a color ink orifice row and a color orifice row 6 for discharging color inks (Y, M, C) are provided between the photo color orifice row 23 and the color orifice row 24 at the center of the top plate 1. The concave portions 9 are ribs provided in the concave portion 6.

[0005] This two-row arrangement is particularly advantageous when the top plate 1 is manufactured by injection molding, since the dies can be manufactured so that the first row and the second row are symmetrical. Is excellent in mass productivity as compared with the configuration having the above arrangement.

[0006]

However, in the above-mentioned conventional example, the liquid chamber is constituted by the liquid channel groove and the liquid chamber frame provided on the wiring board 2 having the resistive heating element.
Is pressed against the top plate 1 by the elastic body 3. 1) Near the boundary of each color of the top plate 2, “shrinkage” occurs at the time of molding due to the influence of the liquid chamber frame 20 (see FIG. 5 described later), and the resistive heating is performed. There is a problem that the adhesiveness between the substrate 2 having the elements and the liquid flow channel groove is deteriorated, resulting in uneven printing.

2) Further, if the "closed" portion is pressed against the substrate 2 with a stronger elastic body 3, each orifice of the top plate 1 may be distorted.

3) Further, the orifice rows 23 and 24 when the ink jet recording head unit 10 is completed are
It may be different from the time of completion.

In order to solve the above problems 1) to 3), for example, Japanese Patent Application Laid-Open No.
According to Japanese Patent Application Laid-Open No. 119285/1992, a method of inserting a wedge into the concave portion 8 provided between the photo-color ink orifice row 2 and the color orifice row 24 at the center of the top plate 3 has been used. However, satisfactory adhesion of the black head unit having the black orifice row cannot be sufficiently obtained by the above-mentioned conventional method.

The present invention has been made in view of the above situation, and has as its object to provide means for further improving / eliminating the above problems.

[0011]

SUMMARY OF THE INVENTION Therefore, in the present invention, there is provided an ink jet recording head according to any one of the following items (1) to (6) to achieve the above object. It is.

(1) A ceiling in which two liquid passage groove groups for forming a liquid passage, two liquid chamber frames and an ink introduction passage are formed, and a plurality of ink discharge ports are arranged in two rows. A plate, two substrates on each of which a plurality of resistive heating elements for respectively discharging ink are formed, corresponding to the two ink discharge ports, and the substrate and the top plate for each substrate. And two first elastic members that are pressed and fixed, and the liquid flow path and the liquid chamber are formed by joining the substrate and the top plate, and between the ink discharge port rows of the top plate. Is an ink jet recording head in which a groove separating an ink ejection port array is formed, and a groove is formed in the top plate, a second elastic member is provided, and a notch is formed at a load application point of the second elastic member. An ink jet recording head characterized by being provided De.

(2) The notch of the second elastic member is
The ink jet recording head according to the above (1), wherein the ink jet recording head corresponds to the warpage of the liquid channel groove row of the top plate.

(3) The notch of the second elastic member is
The ink jet recording head according to the above (1), which corresponds to the shape of the liquid chamber frame of the top plate.

(4) The ink jet recording according to (1), wherein a flexible wiring board having connection pads for making electrical contact with the carriage is connected to the board, and the wiring board is fixed to the top plate. head.

(5) An ink jet recording head, characterized in that the top plate according to (1) is a resin integrally formed.

(6) An ink discharge port array is provided with ribs in the vicinity of both ends of the groove in the direction perpendicular to the groove.
The inkjet recording head according to the above.

[0018]

According to the construction of the present invention as described above, the minimum force can be attained by inserting an elastic member provided with a notch at the load application point into the concave portion provided in the center of the top plate and provided in the two orifice rows. By pressing the substrate against the top plate with the elastic body, it is possible to 1) improve the adhesion and eliminate uneven printing, and 2) minimize the deformation of the orifice row.

3) Even when the ink jet recording head unit is completed, the arrangement of orifice rows on the top plate alone can be reproduced.

4) Further, by changing the position of the cutout of the elastic body, the adhesion of the black head unit can be improved.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail based on a plurality of examples with reference to the drawings.

[0022]

(Embodiment 1) FIG. 1 is a perspective view showing the structure of an ink jet recording head unit 10 according to Embodiment 1 of the present invention (corresponding to FIG. 10 of the conventional example).

In FIG. 1, 1 is a top plate provided with a liquid flow channel liquid chamber and an orifice array, 2 is a wiring board for electrically connecting a substrate on which a resistance heating element is mounted and a carriage side, Reference numeral 3 denotes a substrate 2 having the heating element,
The elastic bodies 23 and 24 which are pressed against and fixed to the top plate 1 are perforated and each photo color ink (y, m, c) is formed.
And a color ink orifice row and a color orifice row 6 for discharging color inks (Y, M, C), respectively, are provided at the center of the top plate 1 and are liquids discharged from a photo color orifice row 23 and a color orifice row 24. Recesses provided to prevent mixing of
Is a rib provided in the concave portion 6, and 25 is a V-shaped elastic member (leaf spring) having a notch 28 at each load application point.

FIG. 2 is an exploded perspective view showing the detailed configuration of the ink jet recording head unit 10 shown in FIG. 1, and is a schematic diagram drawn so that the outline of the component configuration and assembly can be understood. In FIG. 2, reference numeral 4 denotes a substrate including the above-described plurality of resistive heating elements, which is a wiring substrate 2TAB (Tape).
It is electrically connected by Automated Bonding mounting.

FIG. 3 is a sectional view of the ink jet recording head unit 10 shown in FIG. In FIG.
Is a liquid introduction path for guiding the ink from the ink container to the liquid chamber, and the ink passes through the liquid introduction path 7 via the ink supply port 34 and flows between the top plate 1 and the substrate 4 having the resistive heating element. The liquid enters the formed liquid chamber 8, and further from the liquid chamber 8, enters the liquid introduction passage 7 having the resistive heating element. Then, the discharge port 5 is formed by film boiling caused by the thermal energy of the resistive heating element.
Is discharged from.

FIGS. 4A and 4B are diagrams showing the warpage of the liquid flow channel of the color head unit. FIG. 4A is a plan view of the orifice row of the top plate 1 as viewed from above, and FIG. FIG.

In FIG. 4B, reference numeral 20 denotes a liquid chamber frame for each color, and reference numeral 26 denotes a liquid channel groove forming portion. FIG. 5 is an enlarged perspective view of each color space.

In FIGS. 1 to 3, the top plate 1 is integrally formed, and the photo color ink orifice row 23 or the color ink orifice row 24, the liquid flow channel groove 26, the liquid chamber frame 20, and the liquid introduction path 7 are It is processed by molding or laser processing.

The orifice rows 23 and 24 and the liquid flow channel 26 need to be processed with high precision. In addition, it is necessary to select a material which is hard to be immersed in the ink or the moldability of these integrally molded products. As a specific material, polysulfone is preferable, but other materials may be used.

At this time, as shown in FIG. 4B, the liquid channel groove forming portion 26 warps the three peaks of several μm due to the difference in thickness between the liquid chamber 8 and the liquid chamber frame 20. Will happen. In this case, in particular, the adhesion between the substrate 4 having the resistive heating element in the intercolor portion and the liquid flow channel 26 is deteriorated, and “uneven printing” occurs at the end portion of each color. Is cut in the elastic member 25 so as to press.

The V-shaped elastic member 25 is inserted into the concave portion 6 before the wiring board 2 is fixed to the top plate 1 by the elastic body 3 or the wiring board 2 is fixed to the top board 1 by the elastic body 3. Insert after fixing with. In the first embodiment, a V-shaped elastic member formed of a SUS plate is used, but a U-shaped elastic member may be used. Further, a material such as an elastomer may be used.

The liquid chamber 8 is formed by the top plate 1 and the substrate 4 having a resistive heating element. In order to completely seal the space therebetween and to prevent ink leakage, the liquid chamber 8 has a substrate 4 having a resistive heating element.
Is pressed against the top plate 1 by the elastic body 3 and then sealed with a sealant.

FIG. 6 is an external perspective view of an ink jet printer having the ink jet recording head according to the first embodiment of the present invention.

In FIG. 6, reference numeral 50 denotes a carriage on which a recording head is mounted. Reference numeral 51 denotes a head cap for preventing ink from being dried from a plurality of orifices formed at the tip of the head for discharging ink, and a head. Is a head recovery unit in which a suction pump for sucking ink from a plurality of orifices when the operation of the device is defective is incorporated. 5
Reference numeral 2 denotes a paper feeding surface on which recording paper is conveyed.

The black ink cartridge 61 and the color ink cartridge 62 are mounted on the carriage 50 in a horizontal line. The carriage 50 includes the recovery unit 5
The position on 1 is the home position, and printing is started by starting to operate leftward in the figure.

FIG. 7 shows a holder 30 provided with a plurality of ink jet recording units 10 each having an ink ejecting portion constituting an ink jet recording head according to the first embodiment of the present invention, and an ink tank mounted on the holder 30. 4
FIG. The holder 30 connects the ink jet recording head unit 10 and the ink tank 40 and holds the ink tank 40.

The ink jet recording head unit 10 according to the first embodiment has a structure in which two rows of color ink orifices are provided. One row 23 uses a low density color ink, and the other row 24 uses a high density color ink. The ink is ejected. By doing this,
Even if the head unit is repeatedly attached and detached, the light ink and the dark ink are prevented from being mixed by the groove provided in the supply port group of the head.

On the bottom surface of the holder 30, each flow path 32a, 32b, 32c for guiding ink to the ink discharge portion of the ink jet recording head unit 10 and each flow path 3 not shown
A flow path forming member 31 in which 2d, 32e, and 32f are formed is provided. The flow path forming member 31 includes the flow paths 32a, 32b, 32 formed inside the flow path forming member 31.
c, a transparent material such that the ink running out of the liquid tank 40 can be confirmed by the mixture of the bubbles by visually checking the state of the ink such as the ink introduced into the ink head unit 10 and the bubbles mixed in the ink. It is preferable to be formed in this way, and it is comprised in this way.

The ink tank 40 is formed so as to be mounted on the holder 30, and a plurality of supply ports 41 are provided at the bottom corresponding to the number of ink jet recording head units of the holder 30, and six supply ports 41 are provided in the first embodiment. For example, six types of dark yellow ink, dark magenta ink, dark yellow ink, light magenta ink, and single cyan ink are separately stored in the liquid tank 40.

(Second Embodiment) In the first embodiment, the color head unit has been described. Next, in the second embodiment, the black head unit will be described.

Since the configuration of the recording head 10 is the same as that in the first embodiment, repeated description will be omitted.

FIG. 8 is a view of the black head unit viewed from the same direction as in FIG. 4 of the first embodiment.
(A) is a plan view, and (b) is a front view as viewed from an arrow B. It can be seen that the shape and number of the liquid chamber frame are different from those of the color of the first embodiment. In this case, as compared with the case of FIG. 4, the warpage of the liquid channel groove forming portion 27 has a mountain shape of about 10 μ as shown in FIG. When the substrate 4 having the heating element is pressed by the elastic body 3, the angle of the warp is reversed as shown in FIG. Thereafter, when a straight elastic member such as 25 'is inserted, the warp returns to its original state, as shown in Fig. 3', and the adhesion between the substrate 4 having the heating element and both ends of the liquid flow channel array deteriorates. Become. Therefore, the center of the elastic member 25 'is cut out,
When the pressing force at the central portion is reduced as shown in FIG. 3, good adhesion is obtained over the entire area of the liquid flow groove array 27 as shown in FIG.

[0043]

As described above, according to the present invention,
By inserting an elastic member having a notch at a load application point into a concave portion provided between two orifice rows,
The following effects are obtained respectively.

It is possible to 1) improve the adhesion and eliminate uneven printing, and 2) minimize deformation of the orifice array.

3) Further, even when the ink jet recording head unit is completed, the arrangement of the orifices on the top plate alone can be reproduced.

4) By the above 1) to 3), the printing quality is improved, and the productivity is improved.

5) Further, by changing the position of the cutout of the elastic member, the adhesion of the black head unit can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an inkjet recording head unit according to a first embodiment.

FIG. 2 is an exploded perspective view of the configuration of the unit 10 of FIG.

FIG. 3 is a cross-sectional view schematically showing an internal configuration and a liquid path of the unit 10 of FIG.

FIGS. 4A and 4B are diagrams showing a warpage of a liquid flow channel of a color head unit; FIG.

FIG. 5 is an enlarged perspective view showing a color space.

FIG. 6 is an external perspective view of an example of an inkjet printer including the inkjet recording head according to the first embodiment.

FIG. 7 is an external perspective view of an example of an ink jet printer equipped with the ink jet recording head cartridge of the first embodiment.

FIG. 8A is a plan view illustrating warpage of a liquid flow channel groove of the black head unit according to the second embodiment, and FIG.

FIG. 9 is a schematic diagram showing a change in warpage of a liquid flow channel of the black head unit according to the second embodiment.

FIG. 10 is a perspective view showing the configuration of an example of a conventional ink jet recording head.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 top plate 2 wiring board 3 elastic body 4 substrate 6 concave portion 7 liquid introduction path 8 liquid chamber 9 rib 10 inkjet recording head unit 20 liquid chamber frame 23 photo color ink orifice row 24 color orifice row 25, 25 'elastic member 26, 27 Liquid flow channel groove 28 Notch 30 Holder 31 Flow path forming material 40 Ink tank 41 Supply port 50 Carriage 51 Head recovery unit 52 Paper feed surface 61 Black ink cartridge 62 Color ink cartridge

Claims (6)

[Claims] 1. A top plate in which two liquid flow channel groups for forming a liquid flow channel, two liquid chamber frames and an ink introduction channel are formed, and a plurality of ink discharge ports are arranged in two rows. And a plurality of resistive heating elements for individually ejecting ink corresponding to the two ink ejection ports, respectively.
And two first elastic members for pressing and fixing the substrate and the top plate to each of the substrates, wherein the liquid flow path and the liquid are formed by joining the substrate and the top plate. An ink jet recording head in which a chamber is formed and a groove separating the ink discharge port array is formed between the ink discharge port rows of the top plate, wherein a second elastic member is provided in the groove of the top plate. An ink jet recording head having a notch provided at a load application point of the second elastic member. 2. The ink jet recording head according to claim 1, wherein the notch of the second elastic member corresponds to the warpage of the liquid passage groove array of the top plate. 3. The ink jet recording head according to claim 1, wherein the notch of the second elastic member corresponds to the shape of the liquid chamber frame of the top plate. 4. The ink jet recording head according to claim 1, wherein a flexible wiring substrate having connection pads for making electrical contact with the carriage is connected to the substrate, and the wiring substrate is fixed to the top plate. 5. An ink jet recording head, wherein the top plate according to claim 1 is a resin integrally formed. 6. An ink jet recording head according to claim 1, wherein ribs are provided in the vicinity of both ends of said groove in a direction perpendicular to an ink discharge port array.