JPH1095114A - Ink-jet type line recording head and recording apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attempt the simplification of an ink supply pipe opening to head units and to enable simple replacement of the head units by fixing the units to a support base attachably/detachably in the paper feed direction in stages in a staggering manner in the paper breadth direction. SOLUTION: Head units 40, 41 are arranged in two stages in the paper feed direction (arrow A), the units 40, 41 are plover-shaped and positioned so that the nozzle openings of the end parts of the units 40, 41 are the pitch P of the nozzle opening of each nozzle, and fixed attachably/detachably to a support base 42. The base 42 has a distribution channel 48 for supplying ink introduced from an ink supply opening formed on the back side to an ink distribution opening 50. Since in each head 40, 41, each opening is positioned independently to the base 42 on the basis of a positioning hole, the accumulated error of an ink drop arrival position which is apt to occur in a recording head having numbers of nozzle openings can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-nozzle ink jet recording head constituted by using a plurality of head units.

[0002]

2. Description of the Related Art Ink jet printers are serial systems in which a recording head having a recording height of about the character height is reciprocated in the paper width direction and a predetermined amount of recording paper is fed each time printing of one line is completed. , And has a problem that the printing speed is lower than that of a page printer. In order to solve such problems,
A recording head in which nozzle openings are arranged in a region corresponding to the width of a recording sheet, that is, a so-called line recording head, has been proposed. However, even if the ink ejection capability from one nozzle opening varies, the printing quality is greatly reduced. However, there is a problem that the production yield is extremely low and the cost is high.

In order to solve such a problem, a recording head having a relatively large production yield and a small recording width may be used as a unit, and a plurality of such recording heads may be arranged in the paper width direction to form a recording head having a large number of nozzles. For example, many proposals have been made as disclosed in Japanese Patent Publication No. 2-57506 and Japanese Patent Publication No. 3-5992.

In the case where a line recording head is formed by arranging a large number of units on the same substrate as described above, the cost can be reduced as compared with the case where the line recording head is formed as a single recording head. On the other hand, there is a problem that the work of aligning each unit and attaching it to the support, and a piping for supplying ink to each unit individually are required, and the structure around the support and the head is complicated.

Furthermore, since the nozzle opening rows are discretely provided for each unit, there is a problem that the operation for maintaining the ink discharge capability becomes complicated.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an ink jet recording head comprising a large number of units which can simplify an ink supply path. is there.

Another object of the present invention is to provide a recording apparatus provided with a capping device for maintaining and recovering the ink discharge capability.

[0008]

According to the present invention, there is provided a nozzle plate having a plurality of nozzle openings, a reservoir for receiving ink from outside, and a reservoir and ink supply for supplying ink from outside. A flow path forming substrate having a plurality of pressure generating chambers connected to each of the nozzle openings and connected through a port, an elastic plate sealing the other surface of the flow path forming substrate, A head unit comprising a pressurizing means for pressurizing the chamber, and a support base formed with a flow path for distributing the ink, wherein the head unit can be detachably attached in a plurality of stages in the paper feeding direction in a staggered manner in the paper width direction. It was fixed to the support base.

[0009]

FIG. 1, FIG. 2 and FIG. 3 show an embodiment of a recording head according to the present invention.
2 is a perspective view showing an assembly, FIGS. 2A and 2B are views showing structures on a nozzle opening row forming side and an electrode side, respectively, and FIG.
FIG. 1 is a cross-sectional view showing, in an enlarged manner, the vicinity of two pressure generating chambers. In FIG. 1, reference numeral 1 denotes a flow path forming substrate formed by etching a silicon single crystal substrate.
4 and 5 are cut out by etching so as to form a parallelogram parallel to the crystal orientation <111> of the silicon single crystal substrate.

As shown in FIG. 4, the four sides 2 to 4 intersect with the opposite two sides 2 and 3 and the other two sides 4 and 5 at about 70.5 degrees and 109.5 degrees, respectively. Along with
A wall perpendicular to the surface of the silicon single crystal substrate is provided.

Reference numerals 6 and 7 denote pressure generating chambers formed in parallel with the sides 4 and 5, respectively, wherein the walls in the longitudinal direction are parallel to the sides 4 and 5 and perpendicular to the surface of the silicon single crystal substrate. In this embodiment, two rows are arranged in a zigzag pattern, and the ends on the center side are arranged parallel to a line perpendicular to the sides 4 and 5. The pressure generating chambers 6 and 7 communicate with nozzle opening rows 8 and 9 described later on the center side, respectively.
The third side is connected to reservoirs 12 and 13 to be described later via ink supply ports 10 and 11.

Reference numerals 12 and 13 denote reservoirs each having a concave portion for supplying ink to the pressure generating chambers 6 and 7 in each row. As shown in FIG. Opposite sides 12a and 13a are parallel to sides 2 and 3, sides 12b and 13b opposite sides 4 and 5 are parallel to sides 2 and 3, and other sides 12c and 13c are nozzle opening rows 8 and 9.
Are formed in a substantially triangular shape parallel to
Holes 16 and 17 communicating with the ink introduction ports 14 and 15 are formed at diagonal points where a and the sides 12b and 13b are in contact.

Then, as shown in FIG.
The wall forming b and sides 13a and 13b is also formed as a plane perpendicular to the surface of the silicon single crystal substrate. In the drawings, parentheses <> indicate a surface appearing by etching, and numbers in parentheses () indicate angles with respect to the surface.

Reference numeral 20 denotes a nozzle plate, which has two nozzle opening rows 8 in accordance with the arrangement pitch of the pressure generating chambers 6 and 7.
9 are formed to seal one surface of the flow path forming substrate 1. The nozzle opening rows 8 and 9 are formed so as to be perpendicular to the sides 4 and 5 of the flow path forming substrate 1 because they are formed in accordance with the positions of the pressure generating chambers 6 and 7 described above. I have.

An elastic plate 21 for sealing the other surface of the flow path forming substrate 1 is made of an elastic thin plate made of an electrically insulating material such as zirconia or silicon oxide. , 17 and ink inlets 14 and 15 are formed, and the lower electrode 2 is formed on the surface.
2 are formed.

Each of the ink inlets 14 and 15 is formed as a tube having a flange 34a formed at one end as shown in FIG. 5, and a filter for removing air bubbles and dust in the ink is provided at an outlet thereof. The connecting device 3 configured to house 35
4 is fixed.

Reference numeral 23 denotes a piezoelectric material film formed on the surface of the lower electrode 22 by a film forming method or the like.
The upper electrodes 24 and 25 which are electrically independent from each other are formed at positions facing the respective pressure generating chambers 6 and 7 as shown in FIG.
Lead portions 24b and 25b for connecting the connection terminals 4 and 25 to the connection terminal portions 24a and 25a are formed.

The connection terminals 24a and 25a have high electric resistance in the direction in which the pressure generating chambers 6 and 7 are arranged, that is, in the direction parallel to the plane including the lower electrode. The circuit board 2 is provided via the anisotropic conductive adhesive layers 26 and 27 having high conductivity in the vertical direction, that is, the thickness direction.
8 is fixed. A flexible cable 29 connected to an external drive circuit is connected to the circuit board 28, and a semiconductor integrated circuit 30 that converts print data from the flexible cable 29 into a drive signal is fixed on the surface.

The drive signal from the semiconductor integrated circuit 30 is applied to the conductive patterns 31 and 3 formed on the circuit board 28.
2, and selectively supplied to the individual upper electrodes 24, 25 via the conductive adhesive layers 26, 27.

Reference numerals 38 and 39 denote flow path forming substrates 1.
5 shows a through hole formed at a position facing the reference holes 36 and 37 of the nozzle plate.

FIGS. 6, 7 and 8 show an embodiment of a recording head using the above-described head unit. In the drawings, reference numerals 40 and 41 denote the above-described head units, respectively, in the paper feed direction. (In the direction indicated by arrow A in the figure), the head units 40, 41 in each stage are staggered, and the nozzle openings at the ends of the vertically adjacent head units 40, 41 , 41 and are detachably fixed to the support base 42 while being positioned so as to have a pitch P between the nozzle openings.

The adjacent head units 40 and 41 of each stage
A wiper 7 which is a cleaning member to be described later
Concave portions 44, 45 for accommodating 8, 79 are formed.

The support base 42 is provided with a distribution channel 48 for supplying ink flowing from an ink supply port 47 provided on the back surface side to an ink distribution port 50 described later. On the front side, a step 52 supporting an area of the head units 40 and 41 facing the reservoir according to the arrangement position of the head units 40 and 41, and a head unit 40 and 41
Of the semiconductor integrated circuit 30 are formed.

The head unit 40, 41
Positioning pins 53 and 55 are implanted so as to correspond to the positioning holes 36 and 37, and ink distribution ports 50 and 50 are opened. Flexible cable 2 is provided in recess 54
A connector 56 for connecting the other end of the connector 9 is provided.

In the support base 2 configured as described above,
The other ends of the cables 29 (FIG. 1) of the head units 40 and 41 are connected to the connector 56, and the ink distribution ports 50 and 5 are connected.
Packing 60 having a valve function made of an elastic material at 0
Stuff.

Next, when the positioning holes 36 and 37 of the head unit 40 are aligned with the positioning pins 53 and 55, the ends of the connection pipes 34 and 34 of the head units 40 and 41 are inserted into the openings 60a which are expanded above the packing 60. To position. In this state, the head units 40 and 41 are
2, the head units 40 and 41 are guided by the positioning pins 53 and 55, and
34 moves while pushing and expanding the packings 60, 60 and is accommodated in the concave portion 52 of the support base 42.

When the head units 40 and 41 are recessed in the base 42, the positioning holes 36 and 37 of the nozzle plate 20 are
3, 55, the reservoir area is supported by the steps 52, 52 of the support base 42, and the connecting pipes 34, 34 have elasticity of the packing 60 as shown in FIG. Is fixed to the support base 42.

Thus, each head unit 40, 41
Is that, since each nozzle opening is independently positioned on the support base 42 with reference to the positioning holes 36 and 37, the occurrence of the cumulative error of the landing position of the ink droplet which tends to occur in the recording head having the multiple nozzle openings is reduced. Can be prevented.

The connecting pipes 34, 34 are
Since the distribution ports 50, 50 are fixed to the distribution ports 50, 50 by the elasticity of 0, 60, a slight displacement between the connection pipes 34, 34 and the ink distribution ports 50, 50 is absorbed by the elastic deformation of the packings 60, 60. The liquid-tight state between the two is maintained.

At the stage when all the head units 40 and 41 have been mounted on the support substrate 42, as shown in FIG. 8, the head units 40 and 41 are located in the areas facing the nozzle openings and the areas facing the recesses. Windows 62, 63, 64, 6
The fixing plate 66 provided with
1 and is fixed to the support base 42 with a screw 67 or the like.

FIG. 9 shows an embodiment of a recording apparatus using the recording head 70 described above.
Means that the nozzle opening surface of the recording head 70 faces the platen 71 by the moving means, and the nozzle opening arrangement direction is
The recording head 70 is positioned so as to be parallel to the first axis, and the gap between the recording head and the recording medium on the platen 71 is retracted to a distance suitable for printing or a position where a capping device 73 described below can be brought into contact. It is configured as follows.

Reference numeral 73 denotes the above-described capping device, which is capable of moving back and forth in a direction perpendicular to the nozzle opening surface of the recording head 70 (direction of arrow B in the drawing) and in a vertical direction (direction of arrow C in the drawing). The moving unit 7 moves in the direction (the direction of arrow D in the drawing) parallel to the surface of the head units 40 and 41 in the arrangement area of the nozzle openings of the units 40 and 41.
2 attached.

FIG. 10 shows an embodiment of the above-described capping device 73 with the mounting base omitted, and the nozzle openings of each head unit 40, 41 are adjusted in accordance with the arrangement pitch of the head units 40, 41. The base 75 is provided with caps 76 and 77 for sealing the base member and wipers 78 and 79 made of an elastic plate constituting a cleaning member between the caps 76 and 77. Each cap 76, 77
Is connected to a suction pump (not shown) via a tube 80 so as to be supplied with a negative pressure. The capping device main body thus configured is supported by the mounting base so as not to hinder the printing operation and the cleaning operation.

In this embodiment, when an ink tank (not shown) is connected to the ink supply port 47, ink flows into each ink distribution port 50 via the distribution channel 48 of the support base 42.

When the capping device 73 is brought into contact with the recording head 70 in this state, the nozzle openings 8 and 9 (FIG. 1) of the head units 40 and 41 are closed by the cap 76 as shown in FIG. Sealed. Then, when a negative pressure from a negative pressure generating means such as a suction pump (not shown) is applied, the negative pressure acts on the reservoirs 12 and 13 via the pressure generating chambers 6 and 7, and the reservoir 1 and the ink inlets 14 and 15 are used.
Flow into 2 and 13. The ink flowing into the reservoirs 12 and 13 further flows into the pressure generating chambers 6 and 7 via the ink supply ports 10 and 11 and is discharged from the nozzle opening rows 8 and 9.

The reservoirs 12 and 13 are connected to the ink inlet 1
4 and 15, the flow rate does not decrease in areas far from the ink introduction ports 14 and 15 even though the flow rate of the ink decreases, and the ink supply ports 10 and 11 are reduced. Via pressure generating chambers 6 and 7
When the ink flows into the reservoirs 12 and 13, the bubbles are discharged from the nozzle opening rows 8 and 9 via the pressure generating chambers 6 and 7, regardless of the presence of bubbles in any of the reservoirs 12 and 13.

In this manner, when the recording heads 40 and 41 are completely filled with ink, the capping device 7
0 is moved to the platen side, then lowered and retracted from the recording head 70 (the state shown by the dashed line in FIG. 9). Then, the distance between the recording head 70 and the platen 71 is adjusted to a printable distance by the moving device 72.

When print data is output from a host device (not shown), this signal is input to the semiconductor integrated circuit 30 via the cable 29, converted into a drive signal corresponding to the print data, and supplied to the upper electrodes 24 and 25. . This allows
Only the area to which the drive signal of the piezoelectric vibrator is supplied selectively undergoes bending displacement, and the specific pressure generating chambers 6 and 7 expand,
The ink is contracted to suck the ink into the pressure generating chambers 6 and 7 and pressurize the ink, and the nozzle opening rows 8 and
Ink droplets are ejected from the nozzle openings 9 to form dots on the recording medium of the platen 71.

By the way, even if there is a large difference in the coefficient of thermal expansion between the material forming the support base 73 and the material forming the head units 40, 41, the head units 40, 41
Is small in size with respect to the support base 73, the stress due to the difference in thermal expansion acting on the head units 40 and 41 is small, and the displacement of the dot landing position due to the temperature change,
In addition, damage to the head unit can be prevented.

When the capping device 73 is moved toward the recording head 70 at the stage when printing is completed, the tips of the wipers 78 and 79 are opposed to the concave portions 64 and 65 respectively.
The caps 76 and 77 seal the nozzle openings of the head units 40 and 41, respectively.

When the ink discharge performance is reduced by printing for a long time, the tips of the caps 76 and 77 are separated from the nozzle plate 20, and the tips of the wipers 78 and 79 abut against the head units 40 and 41 to elastically deform. The capping device is slightly retracted to the position for receiving the nozzle (FIG. 11 (b)), and the capping device is aligned with the nozzle openings (direction indicated by arrow D in the figure).
When reciprocating, the wipers 78 and 79 resiliently contact the corresponding head units 40 and 41 by their own elasticity to wipe the nozzle openings, and wipe off ink residue and paper dust near the nozzle openings.

When the wiping operation is completed, the recording head 72 is sealed by the capping device 73 and ink droplets are ejected from the nozzle openings to recover the meniscus.
Prepare for the next print.

The head unit 40,
When a failure occurs in the head 41, the fixing plate 66 is removed from the head units 40 and 41, and the packing 60 and the packing 60 are moved in a direction perpendicular to the head unit mounting surface of the support base 72.
60 to overcome the elastic force of the head unit 40.
, And the head unit 40 is removed from the support base 72.

When the connecting pipe 34 comes out of the packing 60,
The packing 60 seals the opening 60 a by its own elasticity to prevent the ink from leaking from the distribution channel 48 and the distribution channel 48.
Prevent air from entering the air.

Next, the positioning hole 3 of the head unit 40
When the head unit 40 is pushed toward the support base with the positioning pins 6 and 37 aligned with the positioning pins 53 and 54, the head unit 4
Numeral 0 is guided by the positioning pins 53 and 54, and the connecting pipe 34 moves while pushing and expanding the packing 60 to enter the recess 52, and the connecting pipe 34 is fixed to the support base 42 by the elasticity of the packing. When the fixing plate 66 is fixed to the support base 42, the replacement of the head unit 40 is completed.

In the above-described embodiment, the entire recording head is sealed by the same capping device. However, as shown in FIG. 11, the head units 40, 41 of each stage constituting the recording head. Caps 76 and 77 and wipers 78 on different bases 81 and 82 corresponding to
79, the bases 81, 82 can be moved independently, and independent suction pumps are connected to the caps 76, 77 of each stage via tubes 83, 84, respectively. The head can be sealed more finely and the cleaning can be performed corresponding to the head unit.

[0047]

As described above, according to the present invention, a nozzle plate having a plurality of nozzle openings is provided,
A reservoir for receiving supply of ink from the outside, a flow path forming substrate having a plurality of pressure generating chambers connected to the reservoir via the ink supply port and communicating with each of the nozzle openings, and the other surface of the flow path forming substrate A head unit composed of an elastic plate for sealing the pressure generating unit and a pressurizing unit for pressurizing the pressure generating chamber, and a support base on which a flow path for distributing the ink is formed. Since the ink supply pipes to a plurality of head units can be simplified, the head units can be easily replaced because they are fixed to the support base in a staggered manner so as to be removable in the paper width direction.

[Brief description of the drawings]

FIG. 1 is an assembled perspective view showing an embodiment of a recording head according to the present invention.

FIGS. 2 (a) and 2 (b) show the nozzle opening side,
FIG. 3 is a diagram showing a structure on the electrode side.

FIG. 3 is an enlarged view showing a structure near one pressure generating chamber in the recording head in a cross section taken along line AA in FIG.

FIG. 4 is a diagram schematically showing an etched surface of a flow path forming substrate constituting the recording head.

FIGS. 5A and 5B are enlarged views showing a state immediately before fixing a head unit to a support base, and a vicinity of a distribution port and a connecting pipe in a fixed state, respectively.

FIG. 6 is a plan view showing an embodiment of the recording head of the present invention with a fixing plate removed.

FIG. 7 is a perspective view showing an embodiment of the recording head of the present invention with a fixing plate removed.

FIG. 8 is a perspective view showing an embodiment of the recording head of the present invention.

FIG. 9 is a perspective view showing one embodiment of a recording apparatus using the recording head of the present invention.

FIG. 10 is a perspective view showing one embodiment of a capping device.

FIGS. 11A and 11B are diagrams respectively showing a sealing state of a recording head by a capping device and a cleaning state. FIG.

FIG. 12 is a perspective view showing another embodiment of the capping device.

[Explanation of symbols]

 Reference Signs List 1 flow path forming substrate 2, 3, 4, 5 side 6, 7 pressure generating chamber 8, 9 nozzle opening row 10, 11 ink supply port 12, 13 reservoir 14, 15 ink introduction port 16, 17 hole 20 nozzle plate 21 elasticity Plate 22 Lower electrode 23 Piezoelectric vibrating plate 24, 25 Upper electrode 29 Flexible cable 30 Semiconductor integrated circuit 30 34 Connection tube 35 Filter 40, 41 Head unit 42 Support base 44, 45 Wiper accommodating recess 47 Ink supply port 64 Concave 50 Ink distribution port 52 Stepped portion 56 Connector 53, 55 Positioning pin 54 Depression 60 Packing 64 Depression 66 Fixing plate 70 Recording head 71 Platen 72 Moving device 73 Capping device 76, 77 Cap 78, 79 Wiper

Claims (9)

[Claims] 1. A nozzle plate having a plurality of nozzle openings, a reservoir receiving ink supply from the outside, and a plurality of pressures connected to the reservoir via an ink supply port and communicating with each of the nozzle openings. Distributing ink; a head unit including a flow path forming substrate having a generating chamber, an elastic plate for sealing the other surface of the flow path forming substrate, and pressurizing means for pressing the pressure generating chamber; An ink jet recording head comprising a support base having a flow path formed therein, wherein the head units are removably fixed to the support base in a plurality of stages in a paper feed direction in a staggered manner in a paper width direction. 2. A connection pipe, which communicates with a reservoir and protrudes to the outside, is fixed to the recording head unit, and a connection port which communicates with the distribution channel and elastically holds the connection pipe is formed. The ink jet recording head according to claim 1, wherein: 3. The ink jet recording head according to claim 2, wherein a filter is housed in the connection pipe. 4. The ink jet recording head according to claim 2, wherein a packing which is always closed at the connection port and is opened by inserting the connection pipe is inserted. 5. The ink jet type according to claim 1, wherein a positioning hole having the nozzle opening as a reference position is implanted in the head unit, and a positioning pin inserted into the positioning hole is implanted in the support base. Recording head. 6. An ink jet recording head according to claim 1, wherein each of said head units is provided with drive circuit means for converting a print signal supplied from outside into a drive signal. 7. The ink jet recording head according to claim 6, wherein a connector for connecting to an external drive circuit is provided on the support base, and the drive circuit means is connected to the connector via a flexible cable. 8. A nozzle plate provided with a plurality of nozzle openings, a reservoir receiving ink supply from the outside, and a plurality of pressures connected to the reservoir via an ink supply port and communicating with each of the nozzle openings. Distributing ink; a head unit including a flow path forming substrate having a generating chamber, an elastic plate for sealing the other surface of the flow path forming substrate, and pressurizing means for pressing the pressure generating chamber; An ink jet type recording head comprising a support base having a flow path formed therein, the head units being removably fixed to the support base in a staggered manner in a paper feed direction in a plurality of stages in a paper width direction; A cap is provided at a position opposing the nozzle opening row of the unit, and a capping device provided with a wiping member between the caps is provided so as to be able to advance and retreat with respect to the recording head. An ink jet recording apparatus. 9. The ink jet recording apparatus according to claim 8, further comprising a recess for accommodating the wiping member when the recording head is sealed by the capping device.