JPH10151741A - Ink jet recording head unit and ink jet recording head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the joint between a plurality of head units arranged to constitute a recording head and a flexible cable. SOLUTION: The side walls at the opposite ends of nozzle openings 6, 7 make an angle α to the arranging direction of the nozzle openings. Third and fourth side walls 2, 4 on the opposite sides are shifted by an amount ΔL when the adjacent nozzle openings of a plurality of head units are arranged with respect to the arranging line of nozzle opening at the upper and lower ends at the arranging pitch of nozzle opening of each head unit thus aligning the joint terminal part of respective head units vertically to the side edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pressure generating chamber provided in a partial area of a pressure generating chamber communicating with a nozzle opening.
The present invention relates to an ink jet recording head in which a plurality of head units for generating ink droplets by pressurizing ink in a pressure generating chamber are arranged in tandem, and more particularly to a wiring structure for supplying a drive signal to each head unit.

[0002]

2. Description of the Related Art In order to cope with high-speed printing and high-density printing, the number of nozzle openings per recording head has been increased. However, an ink jet recording head uses a liquid called ink. In relation to this, it is necessary to form a large number of nozzle openings and pressure generating chambers with uniformity and high accuracy because they are sensitive to the effects of non-uniformity such as fluid resistance in the flow paths of nozzle openings and pressure generating chambers. In addition, if a defect occurs in one of the flow path and the pressure generating means, the printing quality is extremely reduced and the recording head is no longer used, so that the production yield is considerably higher than other recording heads. Have the problem of being low.

In order to solve such a problem, a recording head having a relatively small number of nozzles is constructed, and a plurality of such recording head units are fixed to one substrate to constitute one recording head. However, since the thickness of the wall of the adjacent unit is equal to or larger than the arrangement pitch of the nozzle openings, it is necessary to displace the unit by the width of one unit in a zigzag manner. There is a problem that it becomes about twice as large.

In order to solve such a problem, the present applicant has previously provided a plurality of pressure generating chambers 61 for pressurizing ink by pressure generating means as shown in FIG. The nozzle openings 62 are arranged in a line while being inclined at an angle α, and the upper and lower side walls 63 of the nozzle openings 62 are inclined by an angle α in the arrangement direction of the nozzle openings 62, and the side walls 65 on both sides are arranged in the arrangement direction of the nozzle openings 62. A plurality of head units 66 configured to be parallel to
7 is proposed.

[0005] According to this, since the wall surfaces 63 facing the head units are inclined, if they are shifted in parallel along the wall surfaces 63, the pitch of the nozzle openings 62 of the head units 66 facing each other becomes less than the pitch. The head unit 66 can be adjusted, and the offset amount ΔS in the width direction of the head unit 66 can be reduced, so that a recording head having a relatively small width can be configured.

[0006]

However, a step is generated between the units due to the offset existing between the units, and the alignment between the connection terminals arranged on both sides of the recording head unit and the connection terminals of the flexible cable is performed. There is a disadvantage that errors tend to occur and connection of a flexible cable becomes difficult. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a recording head unit that can accurately position a connection portion of a flexible cable. It is another object of the present invention to provide a recording head using a plurality of the recording head units.

[0007]

According to the present invention, in order to solve such a problem, the nozzle openings are arranged at a predetermined angle α with respect to the arrangement direction of the nozzle openings for ejecting ink droplets. A pressure generating chamber communicating with the pressure generating chamber, pressure generating means for pressurizing the pressure generating chamber, and a connection terminal for supplying a drive signal to the pressure generating means by being connected to an electrode of the pressure generating means by a conductive means. In the recording head unit, the first and second side walls located at both ends of the nozzle opening have the angle α with respect to the direction in which the nozzle openings are arranged, and the third and fourth side walls on both sides are vertically At each end, with respect to the arrangement line of the nozzle openings, the nozzle openings adjacent to the plurality of head units have a displacement amount when arranged in accordance with the arrangement pitch of the nozzle openings of each head unit. Formed.

[0008]

When a plurality of head units are arranged, the entire side wall is aligned in a straight line, and the connecting terminal portion is positioned perpendicular to the side wall. By simply forming the recording head unit in a predetermined shape, the positioning can be performed by matching the side wall of the recording head unit.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of the present invention. 1 and 2 show an embodiment of an ink jet recording head using a recording head unit according to the present invention, with a flexible cable removed, and a schematic diagram showing a cable for supplying a drive signal. In the figure, reference numerals 1, 1, and 1 denote recording head units characterized by the present invention having the same structure. In each unit, the outer peripheral side walls 2, 3, 4, and 5 have a parallelogram shape. It is formed as follows.

In the central area of each unit 1, 1, 1, two rows of nozzle openings 6, 7 are parallel to each other so as to have an inclination of an angle α with respect to the side walls 3, 5 so as to fill each other. The connection terminals 8, 8, 8 ９, 9, 9. 9, 9} are formed.

Each of the units 1, 1, 1 is fixed to a fixing substrate, in this embodiment three nozzle plates 10, so that the side walls 2, 4 on both sides of the units are located substantially in a straight line. I have. Reference numerals 11 and 12 in the drawings denote through holes for positioning.

On the other hand, the flexible cable 13 is made of a flexible conductive material obtained by attaching a metal foil C made of copper or the like (see FIG. 4) to a base material B of a heat-resistant electrical insulating film such as polyimide, and constitutes a recording head. Head unit 1,
The length of the recording head unit 1, 1, 1, 1 is equal to the length of the recording head unit 1, 1, 1, 1.
９, 9, 9, 9 and ‥‥, so that they can be bent and connected to the piezoelectric vibrators 37 and 38 as shown in FIG. The head unit 1 is cut in a band shape so as to have a large width of about ΔW, and
Connection terminal portions 16, 16, 16, having the same arrangement pitch as the connection terminal portions 8, 8, 8,..., 9, 9, 9,.
１７, 17, 17, 17, and ‥‥ are formed so as to extend in a direction perpendicular to the side edges 14, 15.

In this embodiment, a semiconductor integrated device (not shown) for generating a drive signal based on an external print signal is mounted on the flexible cable 13 and the drive signal output from the semiconductor integrated circuit is transmitted to the conductive patterns 18 and 1.
8, 18,..., 19, 19, 19, and 19 are configured to supply the connection terminals 16, 17, respectively. In the figure, reference numeral 20 denotes a window for mounting the semiconductor integrated device, reference numeral 21 denotes a conductive pattern for supplying a print signal from an external drive circuit to the semiconductor integrated device, and reference numeral 22 denotes a connection terminal with the external device.

FIG. 4 is a view showing an embodiment of the above-mentioned recording head in a longitudinal sectional structure of a pressure generating chamber.
FIG. 5 is a view showing the arrangement of the pressure generating chambers 32 and 33, the nozzle openings 6, 7 and the ink supply ports 46 and 47 of the pressure generating chamber forming substrate 31 by removing the elastic plate 34 on the upper surface described later.

In FIG. 4, reference numeral 31 denotes a spacer, which is formed on a substrate made of a ceramic plate such as zirconia (ZrO 2) having a thickness suitable for forming the pressure generating chambers 32 and 33 having a depth of about 150 μm. As shown in (1), the pressure generating chambers 32, 33 are arranged such that the longitudinal axis thereof is inclined at an angle α with respect to the arrangement direction of the nozzle openings 6, 7.

In FIG. 5, the two rows of nozzle openings 6 and 7 facing each other are arranged in a staggered manner so that the pressure generating chambers 32 and 33 of each row fill the gap at an equal pitch P in the main scanning direction. Although they are arranged, it is not necessary that the nozzle openings 6 and 7 are arranged at the same pitch in the main scanning direction, and the nozzle openings 6 and 7 may be arranged at the same position in the main scanning direction.

In the embodiment shown in FIG. 5, the distances L1 and L2 and the distances L3 and L4 are determined by the two nozzle openings 6 ', which are located diagonally to the side walls 2, 4 on both sides of the unit 1.
The distance between the nozzle opening 7 'and the nozzle openings 6 "and 7" is set to be equal.

In addition, the position of the nozzle opening row of each unit in the sub-scanning direction is such that when the two units 1 and 1 are vertically arranged, the lowermost nozzle opening of the upper unit 1 and the lower nozzle opening The distance in the sub-scanning direction from the uppermost nozzle opening of the unit 1 located on the side is determined to be equal to the nozzle pitch of the same nozzle opening row in the unit. The position of the nozzle opening row of each unit 1 in the main scanning direction is such that the lower side wall 5 of the unit 1 located on the upper side and the upper side wall 3 of the unit 1 located on the lower side correspond to the outer shape accuracy of the unit 1. And the amount of deviation ΔL between the nozzle opening rows is determined such that the distance ΔG is such that contact or interference does not occur even when the positioning accuracy between the units is considered.
At this time, the side wall 2 has an angle β with respect to the side wall 3 and has an angle γ with respect to the side wall 5.

By adopting the angles of the side walls 2 to 5 and the arrangement of the nozzle openings, the side walls 2 and 4 of the unit 1 can be positioned on the same straight line between the two units 1 and 1. Become.

That is, the nozzle openings 6 and 7 of the unit 1
Is P, the number of the nozzle openings 6 and 7 is N, and the first side wall 2 and the arrangement lines A and A ′ of the nozzle openings 6 and 7 and the third
Is the angle formed by the line B parallel to the side wall 4 of tan θ, tan θ = ΔL / [(N−1) × P + P] = N / (N ×
P) The relationship is set as follows.

As a result, even if the two units 1, 1 are arranged so that their side walls 2, 4 are located on the same line, the rows of nozzle openings 6, 7 between the units are mutually aligned in the main scanning direction. Although the gap is shifted by the distance ΔL and a slight gap ΔG is left in the sub-scanning direction, the pitch of the entire nozzle openings in the sub-scanning direction is the same even near the boundary between the two units 1 and 1 without disturbing the original pitch P of the unit It can be.

Preferably, when the distance ΔL between the nozzle opening rows is set to be an integral multiple of the pitch between the nozzle openings in the sub-scanning direction, the control of the dot formation position in the main scanning direction and the end of the ink droplet ejection timing Control can be simplified.

Numeral 34 denotes an elastic plate which exhibits a sufficient bonding force when fired integrally with the spacer 31.
It is made of a material that is elastically deformed by the flexural vibration of the piezoelectric vibrators 37 and 38 described later, for example, a thin plate of zirconia having a thickness of about 7 μm.

Reference numerals 37, 38 # denote the above-described piezoelectric vibrators, respectively, and the lower electrodes 39, 38 formed on the surface of the elastic plate 34.
A green sheet made of a piezoelectric material is formed on the surface of the piezoelectric element 40 so as to face the pressure generating chambers 32 and 33.

In the figure, reference numeral 41 denotes a cover plate integrally attached to the other surface of the spacer 31. In this embodiment, the cover plate has a thickness of 100 μm.
Nozzle communication holes 42 and 43 connecting the nozzle openings 6 and 7 of the nozzle plate 10 with the pressure generating chambers 32 and 33, and reservoirs 44 and 45 described later.
And ink supply ports 46 and 47 for connecting the pressure generating chambers 32 and 33 to the pressure generating chambers 32 and 33, respectively.

Numeral 48 denotes a reservoir forming plate, which is made of a corrosion-resistant plate made of, for example, stainless steel having a thickness of 150 μm, which is suitable for forming the reservoir, and which has reservoirs 44 and 45, pressure generating chambers 32 and 33 and nozzle openings. Nozzle communication holes 49 and 50 connecting the nozzles 6 and 7 are formed.

Of these members 31, 34, 41, 48, members 31, 34, 41 made of a ceramic material
Are integrally fixed by firing, and then fixed to a reservoir forming plate 48 made of metal or the like by a joining method suitable for joining ceramic and metal.
Is configured.

On the surfaces of the piezoelectric vibrators 37 and 38, upper electrodes 51 and 52 are formed by vapor deposition or the like. At this time, connection patterns 53 and 5 are formed in accordance with the formation of the upper electrodes 51 and 52.
4 are formed.

The connection patterns 53 and 54 are shown in FIG.
As shown in (a), each piezoelectric vibrator 3 extends from the ends of the piezoelectric vibrators 37 and 38 to the vicinity of the side walls 2 and 4 of the unit 1.
7 and 38, and extend in substantially the same direction as the connection terminal portions 8, 38.
It is bent in the direction of 9 and connected to the connection terminals 8 and 9. Reference numerals 55 and 56 in the figure denote insulating layers formed between the lower electrodes 39 and 40 and the connection patterns 53 and 54.

When a plurality of recording head units 1 constructed as described above, in this embodiment three are fixed to the nozzle plate 10, the side walls 2, 4 on both sides of each head unit 1 are positioned on the same line. In addition, the uppermost nozzle opening facing one head unit 1 and the lowermost nozzle opening of another adjacent head unit 1 coincide with the pitch P of the nozzle openings 6 and 7 which is the original head unit. When the distance ΔG is adjusted as described above, each head unit 1, 1,.
1 ‥‥ nozzle openings 6, 6, 6, ‥‥, 7, 7, 7, ‥
‥ are all arranged at the same pitch.

Next, the flexible cable 13 is arranged such that its side edges 14, 15 are parallel to the side walls 2, 4 of the recording head unit 1, 1, 1 #, and each of the connection terminal portions 16, 16, 1
6, ‥‥, 17,17,17, ‥‥ are positioned so as to face the connection terminal portions 8,8,8 ‥‥, 9,9,9 ‥‥ of each head unit 1, and the connection terminal portions 16, 17 and the connection terminal portions 8 and 9 are joined by soldering or the like so as to form a conductive relationship.

When positioning the flexible cable 13, the connection terminals 16 of the flexible cable 13
16, 16, ‥‥, 17, 17, 17, and １７ are formed so as to be substantially perpendicular to respective side edges 14 and 15 of the flexible cable 13, and a plurality of head units 1, 1,. 1, the connection terminals 8, 8, 8,..., 9, 9, 9,.
‥ are formed perpendicular to the side walls 2, 4, so that the side edges 14, 15 of the flexible cable 13 are parallel to the side walls 2, 4 of the head unit 1, 1, 1 、 , 16, 16, ‥‥, 17, 17, 17, ‥‥ are aligned so that all the connection terminals 16, 16, 16, ‥‥, 1
7, 17, 17,... Are all positioned at predetermined positions.

Preferably, the connection terminal portion of the flexible cable 13 is peeled off in a length direction at a constant width, and the copper foil forming the conductive pattern is exposed to form a tab T. Side edge 1 of cable
When bent at a right angle with lines parallel to 4 and 15 and formed into a “Z” shape, the front end side serving as a connection terminal portion is also at a right angle, so that the front end of each tab is connected to the connection terminal portion 7 of the unit 1.
8 can be formed in substantially the same shape.

Therefore, the connection terminals of the flexible cable 13 can be accurately aligned with the connection terminals 7 and 8 of the head unit 1 as described above.

In this embodiment, when a print signal and a drive voltage are supplied from the external drive circuit to the connection terminal 22, the drive signal and the drive voltage are supplied to the semiconductor integrated device (not shown) via the conductive path 21 of the flexible cable 13, A drive signal is supplied to the connection terminals 8, 9 via the conductive patterns 18, 19, and the piezoelectric vibrators 17, 18 of the recording head unit 1, 1, 1, 1 via the connection patterns 55, 56.
Is also supplied with a drive signal. Thereby, the piezoelectric vibrator 3
The pressure generating chambers 32 and 33 expand and contract by flexing and displacing the pressure generating chambers 7 and 38, thereby ejecting ink droplets from the nozzle openings 6 and 7.

In the above-described embodiment, the tab is formed at the end of the flexible cable, and the connection is made via the tab. However, only the insulating layer of the flexible cable on the side facing the recording head unit 1 is used. Peel off the
You may make it connect from a base material.

In the above embodiment, the piezoelectric vibrator is formed by sticking a ceramic green sheet. However, the same effect can be obtained by applying the present invention to a piezoelectric vibrator formed by vapor deposition of a piezoelectric material. Obviously,

Further, in the above embodiment, a semiconductor integrated circuit is provided on the flexible cable to generate a drive signal in the flexible cable area.
Obviously, the same operation is achieved even when a drive signal is generated by an external drive circuit and supplied.

[0039]

As described above, in the present invention,
A pressure generating chamber that is arranged to be inclined at a predetermined angle α with respect to the arrangement direction of the nozzle openings that eject ink droplets and communicates with the nozzle openings, and a pressure generating unit that pressurizes the pressure generating chambers;
In a recording head unit having an electrode of a pressure generating means and a connection terminal connected to the pressure generating means and supplying a drive signal to the pressure generating means, first and second side walls located at both ends of the nozzle opening have a nozzle opening. Angle α to the array direction
The third and fourth side walls on both sides are arranged such that adjacent nozzle openings of a plurality of head units are arranged at the upper and lower ends with respect to the arrangement line of the nozzle openings at the arrangement pitch of the nozzle openings of each head unit. Since it is formed so as to have a deviation amount when arranged together, when a plurality of head units are arranged, the entire side wall is aligned in a straight line, and the connection terminal portion can be positioned perpendicular to the side wall, so that driving Just by forming the flexible cable for supplying the signal in such a shape that the opposite side edges are parallel to each other, it is possible to accurately position the flexible cable by fitting it to the side wall of the recording head unit.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a recording head according to the present invention with a flexible cable removed.

FIG. 2 is a view showing one embodiment of a flexible cable connected to the recording head.

FIGS. 3A and 3B are enlarged views showing a terminal portion formed near a side wall of a head unit and a connection terminal portion on a side edge of a flexible cable, respectively.

FIG. 4 is a view showing one embodiment of a recording head unit constituting the ink jet recording head of the present invention, with a cross-sectional structure near a pressure generating chamber.

FIG. 5 is a diagram showing the arrangement of pressure generating chambers, nozzle openings, and ink supply ports, and the relationship between these and sidewalls.

FIG. 6 is a diagram showing an ink jet recording head using a conventional head unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording head unit 2, 3, 4, 5 Side wall of head unit 6, 7 Nozzle opening 8, 9 Connection terminal part of recording head unit 10 Nozzle plate 13 Flexible cable 16, 17 Connection terminal part of flexible cable 18, 19 Conductive pattern 31 elastic plate 32, 33 pressure generating chamber 37, 38 piezoelectric vibrator 39, 40 lower electrode 44, 45 reservoir 46, 47 ink supply port 51, 52 upper electrode

Claims (9)

[Claims] 1. A pressure generating chamber which is arranged to be inclined at a predetermined angle α with respect to an arrangement direction of nozzle openings for discharging ink droplets and communicates with the nozzle openings, and a pressure generating means for pressurizing the pressure generating chamber And a connection terminal part connected to the electrode of the pressure generating means by a conductive means and supplying a driving signal to the pressure generating means, wherein the first and second terminals located at both ends of the nozzle opening are provided. The second side wall has an angle α with respect to the arrangement direction of the nozzle openings, and the third and fourth side walls on both sides respectively have a plurality of head units at upper and lower ends with respect to the arrangement line of the nozzle openings. An ink jet recording head unit formed so as to have a deviation amount when adjacent nozzle openings are arranged in accordance with the arrangement pitch of the nozzle openings of each head unit. 2. When a plurality of nozzle openings are arranged so that the pitch of the nozzle openings at the lower end and the upper end of an adjacent recording head unit matches the arrangement pitch of the nozzle openings of the recording head unit, the third and fourth arrangements are performed. 2. The ink jet recording head unit according to claim 1, wherein the side wall is configured to be located substantially on the same line. 3. When the pitch of the nozzle openings is P, the number of nozzle openings is N, the deviation is ΔL, and the angle between the third and fourth side walls and the arrangement line of the nozzle openings is θ, tan θ = ΔL / [(N−1) × P + P] = N / (N ×
2. The ink jet recording head unit according to claim 1, wherein the relationship is set as follows. 4. First and second side walls located at both ends of the nozzle opening have an angle α with respect to the arrangement direction of the nozzle openings, and third and fourth side walls on both sides have upper and lower ends. Each of the nozzle openings has an amount of displacement when the nozzle openings adjacent to the plurality of head units are arranged in accordance with the arrangement pitch of the nozzle openings of each head unit with respect to the arrangement line of the nozzle openings, and the pitch of the nozzle openings Is P, the number of nozzle openings is N, the displacement is ΔL, and the angle between the third and fourth side walls and the arrangement line of the nozzle openings is θ, tan θ = ΔL / [(N−1) × P + P] = N / (N ×
P) An ink jet recording head in which a plurality of recording head units configured to satisfy the following relationship are arranged such that the third and fourth side walls of each unit are located on the same line. 5. When a plurality of nozzle openings are arranged so that the pitch of the nozzle openings at the lower end and the upper end of an adjacent print head unit coincides with the arrangement pitch of the nozzle openings of the print head unit, the third and the fourth are set. The ink jet recording head according to claim 4, wherein the recording head unit is configured such that a side wall is located substantially on the same line. 6. A connection terminal portion of the recording head unit having a side edge parallel to the third and fourth side walls of each of the head units and near the side edge so as to extend perpendicular to the side edge. The ink jet recording head according to claim 4, further comprising a flexible cable having a connection terminal portion connected to the recording medium. 7. The ink jet recording head according to claim 6, wherein the connection terminal portion of the flexible cable is formed as a tab. 8. The ink jet recording apparatus according to claim 7, wherein the tab is bent in a “Z” shape so that a constant gap is secured between the main body of the flexible cable and the piezoelectric vibrator. head. 9. The method according to claim 8, wherein the connection terminal portion is a third side wall or a fourth side wall.
Is formed as a tab whose extension direction is substantially perpendicular to the side wall of the flexible cable, and the tab is bent in a “Z” shape so that a constant gap is secured between the main body of the flexible cable and the piezoelectric vibrator. The ink jet recording head according to claim 7, wherein