JP3552004B2 - Ink jet line recording head and recording apparatus - Google Patents

Description

[0001]
TECHNICAL 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]
[Prior art]
Ink jet printers are designed so that a recording head having a recording height about the character height is reciprocated in the paper width direction, and printing is performed by a serial method in which a predetermined amount of recording paper is fed each time printing of one line is completed. It has a problem that the printing speed is lower than that of the page printer.
In order to solve such a problem, there has been proposed 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. Even if it occurs, the printing quality is greatly reduced, so that the production yield is extremely low and the cost is high.
[0003]
In order to solve such a problem, it is also possible to configure a multi-nozzle recording head by arranging a plurality of ink jet recording heads having a relatively high production yield and a small recording width in the paper width direction as a unit. Many proposals have been made as disclosed in Japanese Patent Publication No. 2-57506 and Japanese Patent Publication No. 3-5992.
[0004]
When a line recording head is configured by arranging a large number of units on the same substrate as described above, the cost can be reduced as compared with a case where the line recording head is configured as a single recording head. 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, which complicates the structure around the support and the head.
[0005]
Further, 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.
[0006]
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 including a large number of units that can simplify an ink supply path.
[0007]
It is another object of the present invention to provide a recording apparatus having a capping device for maintaining and recovering the ink ejection ability.
[0008]
[Means for Solving the Problems]
In order to solve such a problem, according to the first aspect of the present invention, a nozzle plate having a plurality of nozzle openings is connected to a reservoir for receiving ink supply from outside, and the reservoir is connected to the reservoir via an ink supply port. A flow path forming substrate provided with a plurality of pressure generating chambers communicating with each of the nozzle openings, an elastic plate sealing the other surface of the flow path forming substrate, and a pressurizing pressurizing the pressure generating chamber. Means, and a support base on which a flow path for distributing the ink is formed, wherein the support unit is detachably provided in a plurality of stages in the paper feed direction, in a staggered manner in the paper width direction. And a plurality of recesses for accommodating a wiper are formed in the support base at positions where the head unit does not exist in the wiping direction.
Further, in the invention according to claim 4 , a nozzle plate provided with a plurality of nozzle openings, a reservoir for receiving ink supply from the outside, the reservoir being connected to the reservoir via an ink supply port, and communicating with each of the nozzle openings A flow path forming substrate having a plurality of pressure generating chambers, an elastic plate for sealing the other surface of the flow path forming substrate, and a head unit including a pressing unit for pressing the pressure generating chamber, A support base in which a flow path for distributing the ink is formed, wherein the head unit is removably fixed to the support base in a plurality of stages in the paper feed direction, in a staggered manner in the paper width direction, and An ink jet type line recording head in which a plurality of recesses for accommodating wipers are formed in positions where the head units do not exist in the wiping direction, and a nozzle opening row of each head unit Comprising a cap on the opposite position, and is also constructed by providing a retractable capping device has wiping member disposed between said cap relative to said recording head.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
1, 2, and 3 each show an embodiment of a recording head according to the present invention. FIG. 1 is an assembly perspective view, and FIGS. And FIG. 3 is an enlarged cross-sectional view showing the vicinity of one pressure generating chamber. In FIG. 3, reference numeral 1 denotes a flow path formed by etching a silicon single crystal substrate. In the substrate, four opposing sides 2, 3, 4, 5 on the outer periphery are cut out by etching so as to form a parallelogram parallel to the crystal orientation <111> of the silicon single crystal substrate.
[0010]
As shown in FIG. 4, these four sides 2 to 4 have opposite sides 2 and 3 and other two sides 4 and 5 intersecting at approximately 70.5 degrees and 109.5 degrees, respectively. A wall perpendicular to the surface of the silicon single crystal substrate is provided.
[0011]
Reference numerals 6 and 7 denote pressure generating chambers formed in parallel with the sides 4 and 5, respectively, having longitudinal walls 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 so as to be parallel to a line perpendicular to the sides 4 and 5. The pressure generating chambers 6 and 7 communicate with the nozzle opening rows 8 and 9 described later on the center side, respectively, and communicate with the reservoirs 12 and 13 described later via the ink supply ports 10 and 11 on the sides 2 and 3 side. I have.
[0012]
Reference numerals 12 and 13 denote reservoirs formed of concave portions for supplying ink to the pressure generating chambers 6 and 7 in each row, and sides facing the sides 2 and 3 of the flow path forming substrate 1 as shown in FIG. The sides 12a and 13a are parallel to the sides 2 and 3, the sides 12b and 13b facing the sides 4 and 5 are parallel to the sides 2 and 3, and the other sides 12c and 13c are parallel to the nozzle opening rows 8 and 9. Holes 16 and 17 communicating with the ink introduction ports 14 and 15 are formed at diagonal points where the triangles 12a and 13a are in contact with the sides 12b and 13b.
[0013]
As shown in FIG. 4, the walls forming the sides 12a and 12b and the sides 13a and 13b are also formed as planes 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.
[0014]
Reference numeral 20 denotes a nozzle plate in which two nozzle opening rows 8 and 9 are formed in accordance with the arrangement pitch of the pressure generating chambers 6 and 7, and seals 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.
[0015]
Reference numeral 21 denotes an elastic plate for sealing the other surface of the flow path forming substrate 1, which is made of an elastic thin plate made of an electrically insulating material such as zirconia oxide or silicon oxide. Ink inlets 14 and 15 are formed at opposing positions, and a lower electrode 22 is formed on the surface.
[0016]
As shown in FIG. 5, each of the ink inlets 14 and 15 is configured as a tube having a flange 34a formed at one end, and a filter 35 for removing bubbles and dust in the ink is accommodated at the outlet side. The connecting tool 34 configured as described above is fixed.
[0017]
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, and the surface of the piezoelectric material film is opposed to the pressure generating chambers 6 and 7 as shown in FIG. Upper electrodes 24 and 25 that are electrically independent are formed, connection terminal portions 24a and 25a are formed at the ends, and lead portions 24b and 25b that connect the upper electrodes 24 and 25 and the connection terminal portions 24a and 25a are formed. Have been.
[0018]
The connection terminals 24a and 25a have high electrical 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, and have a direction perpendicular to the direction in which the pressure generating chambers 6 and 7 are arranged. That is, the circuit board 28 is fixed via the anisotropic conductive adhesive layers 26 and 27 having high conductivity in the thickness direction. A flexible cable 29 connected to an external drive circuit is connected to the circuit board 28, and a semiconductor integrated circuit 30 for converting print data from the flexible cable 29 into a drive signal is fixed on the surface.
[0019]
The drive signal from the semiconductor integrated circuit 30 is selectively supplied to the individual upper electrodes 24 and 25 via the conductive patterns 31 and 32 formed on the circuit board 28 and the conductive adhesive layers 26 and 27.
[0020]
Reference numerals 38 and 39 indicate through holes formed in the flow path forming substrate 1 at positions facing the reference holes 36 and 37 of the nozzle plate.
[0021]
FIGS. 6, 7, and 8 show an embodiment of a recording head using the above-described head unit. Reference numerals 40 and 41 in the drawings denote the above-described head units in the paper feeding direction (in the drawing). (In the direction indicated by arrow A) in two stages, the head units 40 and 41 of each stage are staggered, and the nozzle openings at the ends of the vertically adjacent head units 40 and 41 are It is positioned so as to have a pitch P of the nozzle openings and is detachably fixed to the support base 42.
[0022]
Concave portions 44 and 45 for accommodating wipers 78 and 79, which are cleaning members to be described later, are formed between adjacent head units 40 and 41 in each stage.
[0023]
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 surface side, a step 52 supporting an area facing the reservoir of the head units 40 and 41 in accordance with the arrangement position of the head units 40 and 41, and a concave portion 54 for accommodating the semiconductor integrated circuit 30 of the head units 40 and 41. Are formed.
[0024]
Positioning pins 53 and 55 are implanted in the step 52 so as to correspond to the positioning holes 36 and 37 of the head units 40 and 41, and ink distribution ports 50 and 50 are opened. A connector 56 for connecting the other end of the flexible cable 29 is provided in the recess 54.
[0025]
In the support base 2 thus configured, 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 50 have a valve function made of an elastic material. The packings 60, 60 are inserted.
[0026]
Next, when the positioning holes 36 and 37 of the head unit 40 are aligned with the positioning pins 53 and 55, the distal ends of the connection pipes 34 and 34 of the head units 40 and 41 are located at the openings 60a that expand above the packing 60. When the head units 40, 41 are pushed toward the support base 42 in this state, the head units 40, 41 are guided by the positioning pins 53, 55, and the connection pipes 34, 34 push the packings 60, 60 while spreading. It moves and is accommodated in the concave portion 52 of the support base 42.
[0027]
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 positioned at predetermined positions by the positioning pins 53 and 55, and the reservoir area is supported. The connection pipes 34, 34 are supported by the step portions 52, 52 of the base 42, and are fixed to the support base 42 by the elasticity of the packing 60 as shown in FIG.
[0028]
As a result, in each of the head units 40 and 41, since the respective nozzle openings are independently positioned on the support base 42 with reference to the positioning holes 36 and 37, ink droplets that are likely to be generated in a recording head having a large number of nozzle openings are provided. , It is possible to prevent the occurrence of a cumulative error in the landing position.
[0029]
Further, since the connection pipes 34, 34 are fixed to the distribution ports 50, 50 by the elasticity of the packings 60, 60, a slight positional shift between the connection pipes 34, 34 and the ink distribution ports 50, 50 is as follows. It is absorbed by the elastic deformation of the packings 60, 60, and the liquid-tight state between them is maintained.
[0030]
At the stage when all the head units 40 and 41 have been attached to the support substrate 42, as shown in FIG. 8, windows 62 are formed in the areas facing the nozzle openings of the head units 40 and 41 and the areas facing the recesses. A fixing plate 66 having 63, 64, 65 is brought into contact with the head units 40, 41, and is fixed to the support base 42 with screws 67 or the like.
[0031]
FIG. 9 shows an embodiment of a recording apparatus using the above-described recording head 70. In the drawing, reference numeral 72 denotes a moving means, which moves the nozzle opening surface of the recording head 70 toward the platen 71, The recording head 70 is positioned so that the arrangement direction of the openings is parallel to the axis of the platen 71, and the gap between the recording head and the recording medium on the platen 71 is a distance suitable for printing, or the capping device 73 described below is brought into contact with the recording head. It is configured to retreat to a position where it can be made.
[0032]
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). It is attached to the moving means 72 so as to be able to move in the direction parallel to the surface of the head units 40 and 41 (the direction of arrow D in the figure) in the arrangement area of the 41 nozzle openings.
[0033]
FIG. 10 shows one embodiment of the above-described capping device 73 without the mounting base, and seals the nozzle openings of each head unit 40, 41 in accordance with the arrangement pitch of the head units 40, 41. The base 75 is provided with caps 76 and 77 to be mounted and wipers 78 and 79 formed of elastic plates constituting a cleaning member between the caps 76 and 77. Each of the caps 76, 77 is connected to a suction pump (not shown) via a tube 80, and is configured to receive a negative pressure. The main body of the capping device thus configured is supported by the mounting base so as not to hinder the printing operation and the cleaning operation.
[0034]
In this embodiment, when an ink tank (not shown) is connected to the ink supply port 47, the ink flows into each ink distribution port 50 through the distribution channel 48 of the support base 42.
[0035]
When the capping device 73 is brought into contact with the recording head 70 in this state, the nozzle opening rows 8 and 9 (FIG. 1) of the head units 40 and 41 are sealed by the cap 76 as shown in FIG. You. Next, 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 reservoirs 12 and 13 from the ink introduction ports 14 and 15. Flow into 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.
[0036]
Since the reservoirs 12 and 13 are formed in a triangular shape that becomes narrower as the distance from the ink introduction ports 14 and 15 increases, the flow rate decreases in a region away from the ink introduction ports 14 and 15 even though the ink flow rate decreases. Instead, since the ink flows into the pressure generating chambers 6 and 7 via the ink supply ports 10 and 11, no matter where the air bubbles exist in the reservoirs 12 and 13, the ink flows on the ink flow and the pressure generating chambers 6 and 7 are moved. The ink is discharged from the nozzle opening rows 8 and 9 through the nozzle 7.
[0037]
In this way, at the stage when the ink has been filled into the recording heads 40 and 41, the capping device 70 is moved to the platen side, and then lowered to retract 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.
[0038]
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. As a result, only the region to which the drive signal of the piezoelectric vibrator is supplied selectively undergoes a bending displacement, and the specific pressure generating chambers 6 and 7 expand and contract to suck ink into the pressure generating chambers 6 and 7, The ink is pressurized, and ink droplets are ejected from the nozzle openings of the nozzle opening rows 8 and 9 corresponding to the print data to form dots on the recording medium of the platen 71.
[0039]
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 and 41, the head units 40 and 41 are smaller in size than the support base 73. Therefore, the stress caused by the difference in thermal expansion acting on the head units 40 and 41 is small, and it is possible to prevent the displacement of the dot landing position due to the temperature change and the damage of the head unit.
[0040]
When the capping device 73 is moved toward the recording head 70 at the end of the printing, the tips of the wipers 78 and 79 are accommodated in the recesses 64 and 65 facing each other, and the caps 76 and 77 are moved to the respective heads. The nozzle openings of the units 40 and 41 are sealed.
[0041]
When the ink ejection ability 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 on the head units 40 and 41 and undergo elastic deformation. When the capping device is reciprocated slightly in the direction in which the nozzle openings are arranged (the direction indicated by the arrow D in the figure), the wipers 78 and 79 move to the corresponding head units 40 and 41. The nozzle opening is wiped by elastic contact with its own elasticity to wipe off ink residue and paper dust near the nozzle opening.
[0042]
At the stage where 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 and prepare for the next printing.
[0043]
If the head units 40, 41 fail due to long-term use, the fixing plate 66 is removed from the head units 40, 41, and the packings 60, 60 are mounted in a direction perpendicular to the head unit mounting surface of the support base 72. The head unit 40 is pulled out so as to overcome the elastic force of the above, and the head unit 40 is removed from the support base 72.
[0044]
When the connection pipe 34 comes off from the packing 60, the packing 60 seals the opening 60 a by its own elasticity to prevent leakage of ink from the distribution channel 48 and entry of air into the distribution channel 48.
[0045]
Next, when the positioning holes 36 and 37 of the head unit 40 are aligned with the positioning pins 53 and 54 and the head unit 40 is pushed toward the support base, the head unit 40 is guided by the positioning pins 53 and 54 and the connection pipe 34 is formed. Moves while pushing and expanding the packing 60 to enter the recess 52, and the connection 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.
[0046]
In the above-described embodiment, the entire recording head is sealed by the same capping device. However, as shown in FIG. 11, the recording head corresponds to each of the head units 40 and 41 constituting the recording head. Caps 76, 77 and wipers 78, 79 are attached to different bases 81, 82, respectively, so that the bases 81, 82 can be moved independently of each other. When an independent suction pump is connected to the recording head, the recording head can be more finely sealed and cleaned corresponding to the head unit of the recording head.
[0047]
【The invention's effect】
As described above, according to the present invention, the ink supply ports for a plurality of head units can be simplified, the head units can be easily replaced , and the recording head is configured. in the vicinity of the head unit by placing the wiper Ru can be miniaturized.
[Brief description of the drawings]
FIG. 1 is an assembled perspective view showing one embodiment of a recording head of the present invention.
FIGS. 2A and 2B are diagrams showing structures on a nozzle opening side and an electrode side, respectively.
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 one 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 showing a sealed state of the recording head by the capping device and a cleaning state, respectively.
FIG. 12 is a perspective view showing another embodiment of the capping device.
[Explanation of symbols]
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 plates 24, 25 Upper electrode 29 Flexible cable 30 Semiconductor integrated circuit 30
34 Connection pipe 35 Filter 40, 41 Head unit 42 Support base 44, 45 Wiper accommodating recess 47 Ink supply port 64 Recess 50 Ink distribution port 52 Step 56 Connector 53, 55 Positioning pin 54 Recess 60 Packing 64 Recess 66 Fixing Plate 70 Recording head 71 Platen 72 Moving device 73 Capping device 76, 77 Cap 78, 79 Wiper

Claims (4)

A nozzle plate provided with a plurality of nozzle openings, a reservoir for receiving ink supply from the outside, and a plurality of pressure generating chambers connected to the reservoir via an ink supply port and communicating with each of the nozzle openings. A flow path forming substrate, an elastic plate for sealing the other surface of the flow path forming substrate, and a head unit including a pressing unit for pressing the pressure generating chamber,
A support base on which a flow path for distributing the ink is formed,
The head unit is fixed to the support base so as to be detachable in the paper width direction in a plurality of stages in the paper feed direction, in a staggered manner, and a concave portion for accommodating the wiper is provided at a position on the support base where the head unit does not exist. Ink-jet line recording heads are formed in plurality. 2. The ink jet recording head according to claim 1, wherein the concave portion for accommodating the wiper is formed between the plurality of head units of the support base. 2. The ink jet recording head according to claim 1, wherein the reservoirs of the respective head units receive ink supply from outside via respective independent filters. A nozzle plate provided with a plurality of nozzle openings, a reservoir for receiving ink supply from the outside, and a plurality of pressure generating chambers connected to the reservoir via an ink supply port and communicating with each of the nozzle openings. A flow path forming substrate, an elastic plate for sealing the other surface of the flow path forming substrate, and a head unit including a pressing unit for pressing the pressure generating chamber,
A support base on which a flow path for distributing the ink is formed,
The head unit is fixed to the support base in a plurality of stages in the paper feed direction, in a staggered manner in the paper width direction, and a concave portion for accommodating the wiper is provided at a position on the support base where the head unit does not exist. A plurality of inkjet line recording heads formed in
A recording apparatus comprising: a cap at a position facing a nozzle opening row of each of the head units; and a capping device provided with a wiping member between the caps so as to be able to advance and retreat with respect to the recording head.

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