JPS59209882A - Ink jet recording head and connecting method for the same - Google Patents

Abstract

PURPOSE:To enable to maintain the spacing between nozzles of recording heads with high accuracy, providing opening parts so that a side surface of a substrate bonded to the first or second substrate is exposed. CONSTITUTION:Openings 55A, 55B, 65C, 65D are provided at predetermined positions of the substrates 52A, 52B, 62C, 62D, and the parts of faces A-D to be bonded which parts correspond to the opening parts are exposed. Small holes are provided at centers of the exposed parts of the substrates 53, 63. A plurality of spacers 56 are passed through the small hole parts of the recording heads 50, 60, stepped parts thereof are brought into contact with exposed parts of the faces B, C, and the assembly is fastened by nuts 57. Accordingly, a fixed spacing can be maintained between the face B and the face C. In this case, the spacers 56 are preferably formed from a material having a low coefficient of thermal expansion, e.g., a glass, a ceramic or cast iron.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inkjet recording head in an inkjet recording apparatus, and more particularly to an ink-on-demand type recording head and a method for connecting a plurality of these recording heads.

Conventional inkjet recording devices generally have advantages such as being able to print at high speed with low noise, being able to use inexpensive plain paper, and requiring complex processing such as development.

Furthermore, by reducing the diameter of the dots and shortening the interval between dots, it is possible to record high-resolution images, and it is also effective for recording Chinese characters, figures, colors, etc.

Conventional electric field control methods and charge control methods have been known for this type of inkjet recording apparatus for a long time, but in these methods, in particular, means for forming ink droplets (jetting),
The injection direction control means (deflection) for forming characters requires a complicated and expensive structure.

Therefore, methods with simpler structures have been developed in recent years and are attracting attention. As shown in Japanese Patent Publication No. 53-12138, each time an electric pulse is applied to the electromechanical element of the recording head in response to an electric signal for printing, the volume of the pressure chamber is changed and the nozzle is This is an inkjet recording method (hereinafter referred to as on-demand method) in which small ink droplets are ejected from a recording medium. In this method, ink droplets can be ejected with a low driving voltage (for example, about 100 V), and ink is ejected only when necessary, and the ink circulation that collects the ejected ink that is unnecessary for pen recording. No mechanism is required, so the ink supply mechanism becomes extremely simple, and the device can be made smaller and lower in price.

The on-demand recording head described above had one nozzle in one recording head, but
The structure of a recording head that applied this heat method was published in Japanese Patent Application Laid-Open No.
-35231 publication was disclosed. This is a print head for an on-demand inkjet printing device in which a plurality of nozzles are mounted in one print head.

FIG. 1(2)(B) is a schematic diagram of this method,
FIG. 1(A) is a sectional view and FIG. 1(B) is a plan view thereof.

In both figures, the recording head 1 is composed of an A substrate (first substrate) 2 having four parts 7a inside, and a B substrate (second substrate) 3, which is flexible at least in the part forming the side surface of the pressure chamber 6. has been done. The recording head 1 includes a plurality of nozzles 4,
A plurality of necks 5 and pressure chambers 6 communicating with the nozzle 4
and a common ink chamber 7 distributing ink from the ink tank 8 into said pressure chamber 6, and said part 4.5.6.
．． 7 is a multi-nozzle type recording head having a structure t arranged in the same plane. Recording ink is supplied from the inlet 8 to the common ink chamber 7 of the recording head 1 through an ink supply pipe 9. The common ink chamber 7 is branched into a plurality of pressure chambers 6 that communicate with a plurality of nozzles 4 corresponding to pixels in the vertical direction of the image. Further, a part of the wall of the pressure chamber 6 is an iJ flexible wall, and a piezoelectric transducer IO electrically connected to the electronic pulse generator 11 is adhered to the outside thereof. The piezoelectric transducer 10 is a suitable flexible plate that can be bent inward of the pressure chamber 6 when it receives an electrical signal from the electronic pulse generator 11, and is made of, for example, a piezoelectric crystal. It is glued to the outer wall surface of 6.

In this method, the piezoelectric transducer 10 is caused to rapidly bend the flexible wall of the pressure chamber 60 inward by an electric signal from the electronic pulse generator 11, and the resulting rapid decrease in the volume of the pressure chamber 6 is caused by the internal Dot recording is achieved by ejecting ink as small ink droplets from the nozzle 4 and causing them to fly and reach the opposing recording paper. (Thus, dots in the first row of the required pixels are recorded by on-demand ink ejection by a plurality of nozzle rows, and then the recording head is shifted relative to the recording paper to print the dots in the second and third rows. The dots are recorded one after another to record the required i-patterns such as characters.

The multi-nozzle recording head described above enables faster printing than a single-nozzle recording head, and conventionally the distance between nozzles is 0.2 to 0.4 m.
A nozzle arrangement of 16 nozzles in 7 rows was realized.

However, due to various restrictions, it is difficult to reduce the nozzle spacing in the single row arrangement to 0.2 mm or less. To solve this problem, a multi-nozzle recording head was developed in which multiple nozzles were mounted in two rows in a staggered arrangement by stacking substrates with multiple nozzles arranged in one row.This enabled high-resolution printing that doubled the dot recording density. was achieved. Figure 2 (
5) and (B) are a perspective view and a schematic sectional view of this type of recording head. In these figures, there are substrates 12A, which are the second substrate, on both sides of the substrate 13, which is the first substrate.
The plurality of nozzle rows 14A and 14B, which are connected to each other in a two-row staggered arrangement, are connected to the plurality of pressure chamber rows 16A and 16B and the piezoelectric transducer row 2OA of W@, respectively.
, 20B is compatible. Here, the nozzles, that is, the ink ejection ports are arranged along the bonding surface of the first substrate and the second substrate. The inkjet shown in Figure 2 records characters and figures that require high resolution, such as Chinese characters, by ejecting small droplets of ink from each nozzle on demand while shifting the recording head with such a configuration relative to the recording paper. By providing common ink chambers for the nozzle rows 14A and 14B in the recording head, it is possible to create a head that can print color ink for each nozzle row.

On the other hand, in order to obtain print quality close to that of normal type, it is necessary to increase the density of dots from the sharp nozzle to the needle nozzle. It is extremely difficult to make it 0.05 to 0.15 crane.

FIGS. 3 and 4 show another conventionally proposed recording head, which is disclosed in Japanese Patent Application Laid-Open No. 56-62163. In FIG. 3, the holder 3DK is fixed based on the outer shape of two recording heads 31 and 32 made in the same shape, and the height of the nozzles of one recording head 31 is the same as that of the other recording head 320 and nozzle 34 (r ) Exactly half the difference between height and nozzle pitch.

A holder 41 is manufactured as shown in Figure 4.The two recording heads arranged in this way provide twice the resolution of the conventional one. The nozzles 43 and 44 are positioned and fixed on the basis of the external shape, and the ink droplets are ejected from the nozzles 43 and 44.

However, since the recording head joining methods shown in FIGS. 3 and 4 are based on the outer shape, the dimensional accuracy between the nozzles of the two recording heads is inaccurate due to the dimensional error between the outer shape and the nozzles. This results in a loss of print quality. In addition, the entire recording head including the boulder becomes large and heavy, and the load on the drive system for mounting it on a carriage and moving it at high speed increases.

Purpose of the Invention The present invention maintains the nozzle spacing between the recording heads with high accuracy when combining a plurality of recording heads, and also maintains a lightweight and lightweight structure.
The purpose is to perform coupling using a small coupling means and to eliminate the effects of temperature changes. This aims to provide a recording head-to-recording head combination method that achieves high-resolution printing with excellent print quality, high-speed recording, and even color recording.

Structure of the Invention The first invention of the present application is to bond a second plate having at least a flexible portion to one or both sides of the first substrate, and to
In an inkjet recording head in which a nozzle, an ink flow path, and a pressure chamber are formed facing the joint surface of the substrate and the second plate, and a pressurizing means is provided for each pressure chamber. An ink-end recording head characterized in that an opening is formed in at least a portion of the substrate so that a side surface of the other substrate bonded to the first or second substrate is exposed.

In the second invention of the present application, a second substrate having at least a flexible portion on one or both sides of the first substrate is bonded, and a nozzle and an ink are provided between the first substrate and the second substrate. In an inkjet recording head that forms a flow path and a pressure chamber, and is provided with a pressurizing means for each pressure chamber, another recording head is connected to the surface of the other substrate exposed on a part of the first or second substrate as a reference. 1. A method for joining ink-end printheads, characterized in that a plurality of printheads are joined by holding them together using a connecting member.

EXAMPLES Hereinafter, examples according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a perspective view showing the combined state of the inkjet recording head according to the present invention, and FIG. 6 is a front view of the inkjet recording head as seen from the nozzle surface side. Shame, 60 is a recording head manufactured in almost the same shape, and the central substrate 53, 63,
Substrates 52A, 52B, 62C, 62 joined to both sides and having flexible parts at least corresponding to the pressurizing chambers
The base body is made up of D.

In addition, the above bonding surfaces are A side, B side, 0 side, D side from the left side in the figure.
Hereinafter referred to as the surface. Here 54A% 54B164C16
4D is a row of nozzles formed on each of the A side, B side, 0 side, and D side of the above-mentioned joint surface. The ink supply system including the nozzles may be formed on the side surfaces of the substrates 53 and 63 instead of inside the substrates 52A, 52B, 62C, and 62E.

Further, 51A, 51B\51C, and 61D are piezoelectric transducer elements arranged and bonded on the surfaces of the above-mentioned substrates 52, 52B, 62C, and 62D. The above recording head 50,
The structure of ω is the same as that shown in FIGS.

JdR ports 55A, 55E, 65C, and 65D are located at the positions of the substrates 52A, 52B, 62C, and 62D, and correspond to the openings on the bonding surfaces A, B, 0, and D. The part is I! It's out. In addition, the board 5
A small hole is made in the center of the exposed part of 3.63. The winnow is a columnar spacer serving as a connecting member having a stepped part in order to abut the exposed parts of the joint surfaces B and 0 and hold the joint surfaces at a constant distance, and three to four spacers are suitable for stability. be. Machine screws are formed at both ends of the spacer group and can be tightened with nuts 57Vc. That is, the force of the recording head and the small hole part of the mark? Pass through M several spacer shells so that their stepped portions come into contact with the exposed portions of joint surfaces B and C, and tighten with nuts 57. As a result, the B side and the 0 side can be maintained at an interval of I4. In this case, the spacer 56 can be made of stainless steel or the like, but is preferably made of a material with a small coefficient of thermal expansion, such as glass,
Ceramics, cast iron, etc. are suitable.

The yaku is a spacer that is joined using an adhesive, which is different from the connection method of the spacer. The spacer 58 is made to have a certain length, and after bringing both ends into close contact with the exposed portions of the B side and the 0 side of the bonding surface, the B side and the 0 side where the nozzle is connected are fixed with adhesive. It is held one foot apart.

As the adhesive to be used, a low viscosity ebonized cow thread adhesive or the like is effective. The method of injecting the adhesive is as follows:
At least one narrow slit-like groove is provided on the plane of the peak, and after the spacer 58 is brought into contact with the exposed portion, an adhesive is injected into the narrow groove to create a reference surface for the spacer frame to abut. Adhesion is more reliable because the adhesive penetrates into the inside of the container due to capillary action.

Note that the length of the stepped portion of the spacer % or the total length of the spacer frame is such that the interval between each nozzle row 54A, 54B, 64C, 64D is an integral multiple of the dot interval so that the dot interval on the recording paper is uniform. It can be added like this.

FIG. 7 shows two groups of recording heads, 60 being the spacer 58.
In Figure 0, which is an example of a high-resolution inkjet recording head connected via
4B% 64C164D t)) Each / 7: k hitch d ij All are made to the same dimensions, and the nozzles in each row are arranged with a difference of d/4 from each other. 0 Such a multi-nozzle arrangement is formed. The integrated recording head is mounted on a carriage and moved at a constant speed, ejecting ink droplets on demand and sweeping them against the opposing recording paper, thereby creating a four-way recording head with a single row of nozzles. High resolution recording with twice the dot density is achieved.

FIG. 8 shows a color recording apparatus in which two recording heads 70 and 80 are coupled via a spacer 78. Each recording head 7
0 and 80 are the central substrate 73, wings and their jiNa, respectively.
(7) Tr flexible plates 72Y%72M, 82C, 82K Collared and connected. Each flexible plate 72Y, 72M
, 82C, 82K K U nozzle row 74Y, 74M
584C and 84K were formed, respectively.
(2), magenta (goods) N cyan (Q), black (6
) By supplying and ejecting inks of the four colors, it is possible to form a color image in the form of a donmatrix of the four colors and their mixed colors.

FIG. 9 shows a high-speed recording device in which a plurality of recording heads 91, 92, and 93 are connected via a spacer 9495.

High-speed printing can be achieved by combining a plurality of print head groups in this way and making it possible to simultaneously eject ink droplets from a plurality of nozzle rows.

In the above embodiment, the nozzle array of the recording head is located on the joint surface between the first substrate and the second substrate bonded on both sides of the substrate, and is provided on the second substrate side. Even if the pressure chambers in the ink flow paths are provided on the first substrate side, the uninvented recording head coupling method of maintaining a constant interval with respect to the joint UIJJ as shown in FIG. 1O is still effective. be. At the same time, as shown in the first OFA, the spacer 10
3.104 is not necessarily the first substrate 101A, 102A
One side of the first board 1 does not have to be installed only between the sides of the first board 1.
01A, and the other side may be extended between the side surface of the second substrate 102B. Of course, a spacer may be installed between the second substrates of the recording heads to be connected.

4. Effects of the Invention □ As can be seen from the detailed description of the present invention, the uninvented coupling method and coupling device can adjust the nozzle spacing in multiple rows of multiple recording heads with high precision. In addition, since they can be easily combined, the nozzle arrays of the highly integrated and combined print head can form high-resolution printing close to printed characters, color image printing, and high-speed printing with accurate dot patterns. Furthermore, the nozzle row spacing of each head is less affected by temperature and other changes in the external environment, so accuracy is stable. Furthermore, the coupling method and device of the present invention can avoid an increase in the size and weight of the recording head section and can be easily assembled, making it possible to provide a compact, lightweight, and low-cost recording device. The highly integrated and combined recording head according to the present invention can be widely used in various applications such as block and facsimile machines, in addition to the above-mentioned recording devices of various companies.

[Brief explanation of the drawing]

FIGS. 1(4) and (B) are schematic cross-sectional views and plan views showing an example of an inkjet recording head, a second device, and (B)
1 is a perspective view and a schematic cross-sectional view showing another example of an inkjet recording head, FIGS. 3 and 4 are diagrams showing a previously proposed recording head coupling method, and FIGS. 5 and 6 are diagrams showing a method of combining recording heads according to the present invention. FIGS. 7 to 10 are front views of a high-speed recording apparatus according to the present invention, and other embodiments of the method of connecting inkjet recording heads according to the present invention. Kaku, Seal, 70.80.91.92.93.101.10
2...Record hect 53.63.73, feather, l0IA,
102A...1st +/) board 52A,, 52B
, 62C, 62D, 72Y-72M, 82C-8
2K. 101B, 102B...second substrate 54A,
54B, f54C-64D-74Y-74M-84C
,84K-/suru56, fat, 78.94.95.10
3.104-x pacer agent Yoshimi Kuwahara 48 Kiku 6 figure 10 figure 1 υ call

Claims (1)

[Scope of Claims] (1) A second plate having at least a flexible portion is bonded to one or both sides of the first substrate, and the bonding surface between the first substrate and the second plate is In an inkjet recording head in which a nozzle, an ink flow path, and a pressure chamber are formed facing the substrate, and a pressurizing means is provided for each pressure chamber, at least a part of the first or second substrate is provided with the first or second substrate. An inkjet recording head characterized in that an opening is formed so that a side surface of the other substrate to be bonded to the second substrate is exposed. (2) On the side surface of the other substrate exposed through the opening formed in at least a portion of the first or second substrate,
The inkjet recording head according to claim 1, wherein at least one narrow groove is provided. (3) The inkjet recording head according to claim 1 or 2-1, wherein the pressure means is a piezoelectric element. (4) A second substrate having at least a flexible portion on one or both sides of the first substrate is bonded, and a nozzle and an ink flow path are provided between the first substrate and the second substrate. , of an inkjet recording head which forms pressure chambers and is provided with a pressurizing means for each pressure chamber; 1. A method for joining inkjet recording heads, characterized in that a plurality of recording heads are joined by holding a space between them using a connecting member. (5) The inkjet according to claim 4, wherein the connecting member is a columnar spacer made of a material with a small coefficient of thermal expansion and having at least one set of parallel planes. Method for coupling recording heads. (6)' The method of claim 4 or 4, characterized in that the connecting member is coupled to the plurality of recording heads using screws, adhesives, or a combination thereof. The method for combining inkjet recording heads according to item 5.