JP4082957B2 - Droplet ejection apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a droplet ejection apparatus and an image forming apparatus, and more particularly, by the thickness of the diaphragm to transmit the expansion and contraction of the actuator such as a piezoelectric element in the pressurized liquid chamber to a suitable size, the vibrating plate and the actuator The present invention also relates to a droplet discharge device and an image forming apparatus that prevent adhesion failure and the like from occurring when a diaphragm and a flow path plate are joined.
[0002]
[Prior art]
In general, when electroforming plating is performed by forming a pattern with a non-conductive resist on the electrode substrate, the larger the resist shielding area, the more the electric field at that part concentrates on the electrode part at the resist end, and the plating film thickness increases. There is a tendency to become thicker.
For example, if it is a component with a relatively small pattern such as a nozzle plate, these uneven thicknesses are at a level that does not bother much, but in a component on which many fine patterns are formed such as a diaphragm of an ink jet head The variation in film thickness due to the pattern is large, and the uneven thickness is increased.
[0003]
These uneven thicknesses become a serious problem when the diaphragm and the flow path plate, or between the diaphragm and the actuator are joined. If the uneven thickness is large, an adhesive larger than the uneven thickness is required for complete joining.
Specifically, if the uneven thickness is 10 μm, it is necessary to apply an adhesive having a thickness of 10 μm or more in order to join them completely. Here, the increase in the amount of the adhesive causes the thick portion of the diaphragm to protrude, and the fine pattern portion comes into contact with the adjacent pattern, or the diaphragm portion of the diaphragm is filled with the adhesive.
These are serious defects for the printing characteristics of inkjet heads.
[0004]
[Problems to be solved by the invention]
As described above, the uneven thickness of the vibration part region of the diaphragm affects the joining of the diaphragm and the actuator, and the uneven thickness of the entire diaphragm affects the joining of the diaphragm and the flow path plate.
Accordingly, the present invention is, inter electroforming moving plate and the actuator vibration that is produced by plating, a good bonding property of the vibration plate and the channel plates, the purpose of obtaining a stable droplet discharge device indicia shooting characteristics To do .
It is another object of the present invention to obtain a film thickness correction pattern for leveling for producing a diaphragm .
Further, by forming a recording apparatus using Tokurae was droplet discharge device, and to obtain the images forming apparatus capable of high quality printing.
[0005]
[Means for Solving the Problems]
The present invention is intended to achieve the above object, and the invention according to claim 1 is a liquid droplet ejection apparatus having a vibrating plate made by electroforming plating and having a vibrating portion region formed of a fine pattern. The vibration part region is a rectangular region, and the vibration plate is a droplet discharge device having a plurality of groove patterns only in a diagonal region on the outer periphery of the vibration part region.
[0006]
According to a second aspect of the present invention, in the droplet discharge device according to the first aspect, the fine pattern includes a plurality of vibrating portion rows.
According to a third aspect of the present invention, in the droplet discharge device according to the first or second aspect, the diagonal region is located at an outer peripheral portion in the arrangement direction of the vibration portion row of the ink supply port provided in the vibration plate. It is characterized by.
[0007]
A fourth aspect of the present invention, the droplet ejecting apparatus according to claim 3, wherein the ink supply port is characterized by being kicked set individually corresponding to the vibration part of the vibrating region.
According to a fifth aspect of the present invention, in the liquid droplet ejection apparatus according to the fourth aspect , the ink supply ports are arranged at the same pitch in the same direction as the arrangement direction of the vibrating section row, and have a width in a direction perpendicular to the arrangement direction. Is 3 times or more the width in the arrangement direction.
The invention of claim 6, characterized in that it is a picture image forming apparatus equipped with the droplet discharge device according to claim 1-5.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples shown in FIGS.
(First embodiment)
FIG. 1 is a schematic plan view showing the diaphragm of the first embodiment used in the ink jet head of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.
The diaphragm 1 of the first embodiment shown in FIGS. 1 and 2 is formed by electroforming plating. At the center of the vibration plate 1, there is a fine pattern of vibration portion rows arranged corresponding to a plurality of pressurized liquid chambers formed on a flow path plate (not shown). The vibration part row is composed of a plurality of diaphragms formed at equal intervals, and each diaphragm functions as an individual vibration part 2, and a fine pattern part as a whole is a vibration part region. Moreover, between the adjacent vibration parts 2, and the outer peripheral part of a vibration part area | region are the junction parts 3 to which the flow-path board which is not shown in figure is joined, and it is formed thickly.
An ink supply port 4 for supplying ink to a common liquid chamber formed in the flow path plate is formed on both sides intersecting with the arrangement direction of the vibration unit rows.
In addition, alignment marks 5 that are used when assembling the diaphragm 1 and the flow path plate are formed at appropriate locations on the outer peripheral portion of the vibration section region.
[0009]
The diaphragm shown in FIG. 1 has a thickness so that a flow path plate (not shown) is joined to the surface of FIG. 1 and each pressurized liquid chamber formed on the flow path plate corresponds to each of the plurality of vibration portions 2. It joins by the junction part 3 formed in the meat | flesh. A nozzle plate in which nozzle holes corresponding to the pressurized liquid chamber are formed is joined to the further surface side of the flow path plate.
Further, an actuator made of a piezoelectric element (not shown) or the like is joined to the back surface of the diaphragm in FIG.
[0010]
FIG. 3 is a manufacturing process diagram showing an embodiment of a manufacturing method of a diaphragm used in the ink jet head of the present invention.
First, a conductive substrate 11 is prepared (FIG. 3A), a resist 12 is formed on a portion of the conductive substrate 11 where the ink supply port 4 is formed (FIG. 3B), and thin film electroforming is performed. A thin film 13 to be a diaphragm is formed (FIG. 3C).
Thereafter, patterning for forming a plurality of diaphragms is performed with a non-conductive resist 14 (FIG. 3D), and electroforming is performed to form a thick portion 15 serving as a joining region (FIG. 3D E)).
Next, the resists 12 and 14 are removed (FIG. 3 (F)), and the conductive substrate 11 is peeled off to form the vibration plate 1 in which the vibration portion 2, the joint portion 3, and the ink supply port 4 are formed. (FIG. 3G).
[0011]
When such a diaphragm is formed by electroforming, the electric field concentrates on the outer peripheral portion of the region covered with the resist, and the electroformed film thickness tends to increase. For this reason, it becomes more difficult to form the electroformed plating diaphragm with a uniform film thickness as the integration degree of the head increases and the fine patterns are concentrated and formed.
In the diaphragm 1 shown in FIG. 1, even if the B part and the C part, which are the same vibration part region, are compared, the part B surrounded by the vibration part region is thick, and there is no vibration part region in three directions. The C portion is formed with a small film thickness. This film thickness difference reaches 4 to 5 μm in the case of a diaphragm having a total film thickness of 30 μm. Further, the outer periphery is not surrounded by the vibration part region, and in the D part having no pattern, the film thickness is further reduced, and the uneven thickness amount in the entire diaphragm is close to 10 μm.
[0012]
This uneven thickness causes bonding failure and adhesive sticking at the time of vibration plate-channel plate bonding, vibration plate-actuator bonding.
For this reason, the present invention sets the uneven thickness of the electroformed plating total film thickness in the vibration part region to 3 μm or less, preferably 2 μm or less, and the uneven thickness of the electroformed plating total film thickness in the entire diaphragm. By suppressing the thickness to 5 μm or less, it is possible to obtain an ink jet head with good bondability.
[0013]
(Second embodiment)
FIG. 4 is a schematic plan view showing the diaphragm of the second embodiment used in the ink jet head of the present invention.
In order to reduce the uneven thickness generated in the vibration plate produced by electroforming plating, the thickness of the thick film portion, that is, the joint portion 3 is reduced, the film thickness of the thin film portion, that is, the vibration portion 2 is increased, or both. A combination method is conceivable.
As shown in FIG. 4, the thickness of the thick film portion is reduced by forming the pattern extraction portion 6 where no pattern is formed in the portion where the fine pattern is formed. The wider the pattern punched portion 6, the greater the effect, but even with a width of about 200 to 300 μm, it is possible to reduce the uneven thickness of about 0.5 μm. In order to make the uneven thickness more uniform, it is possible to increase the pattern extraction width at the center of the pattern.
[0014]
(Third embodiment)
The problem here is that there is a concern that the characteristic of the vibration part changes due to the provision of the pattern removal part 6 and the head characteristic changes.
FIG. 5 is a schematic plan view showing a means for solving this problem and showing a diaphragm according to a third embodiment used in the ink jet head of the present invention.
The diaphragm 1 of the third embodiment shown in FIG. 5 has two rows of vibrating portions 2, that is, two vibrating portion rows, and each actuator is joined to an actuator joining position 7 for each row. .
As shown in FIG. 5, it is effective to provide the pattern removing portion 6 in the inter-row portion (the portion not joined to the actuator) of the vibrating portion row in the vibrating portion region. As a result, an ink jet head having good bonding properties without affecting vibration characteristics is formed.
[0015]
(Fourth embodiment)
FIG. 6 shows a means for increasing the film thickness of the thin film portion, and is a schematic plan view showing the diaphragm of the fourth embodiment used in the ink jet head of the present invention.
For this purpose, as shown in FIG. 6, it is effective to form the groove pattern 8 in the outer portion in the column direction of the vibrating portion row of the diaphragm 1. It is desirable that the groove pattern 8 be formed at a pitch equivalent to that of the vibration part row in the vibration part region.
[0016]
(5th Example)
FIG. 7 is a schematic plan view showing the diaphragm of the fifth embodiment used in the ink jet head of the present invention.
Although the diaphragm 1 of the fourth embodiment is provided with a groove pattern on the entire surface, the diaphragm of the fifth embodiment is provided with a groove pattern 8 as a vibrating portion in order to ensure the sealing performance of the joining of the diaphragm and the channel plate. It is provided only in the thinnest region on the outer periphery of the region.
[0017]
(Sixth embodiment)
FIG. 8 is a schematic plan view showing a diaphragm according to a sixth embodiment used in the ink jet head of the present invention.
In the diaphragm 1 of the sixth embodiment shown in FIG. 8, the ink supply ports 4 are individually provided corresponding to the individual vibration portions 2 as means for aligning the film thickness in the vibration portion area and the vicinity of the ink supply ports. By arranging the individual ink supply ports 4 at the same pitch as the arrangement of the individual vibrating portions 2, the film thickness of the partition wall between the ink supply ports is increased, and is approximately equal to the film thickness of the vibrating portion region.
In addition, this effect is greatly affected by the length of the partition wall. When the length is short, the influence of the outer peripheral portion is large and the fluctuation of the film thickness is small. In order to obtain a sufficient effect, the length of about 3 times in the width direction is required.
[0018]
(Seventh embodiment)
FIG. 9 is a schematic plan view showing a diaphragm according to a seventh embodiment used in the ink jet head of the present invention.
When the diaphragm 1 as shown in FIG. 9 was formed so that the total film thickness of the electroforming plating was 30 μm by using the configurations of the first to sixth embodiments together, the measured value was 28 in the vibration part region. It was confirmed that 0.7-30.9 μm, thickness deviation 2.2 μm, and 27.0-30.9 μm and thickness deviation 3.9 μm were achieved throughout the diaphragm.
[0019]
(Eighth embodiment)
Next, an embodiment of an ink jet recording apparatus equipped with the ink jet heads of the first to seventh embodiments will be described. Although the eighth embodiment will be described with respect to an ink jet recording apparatus, the present invention can be similarly applied to a droplet discharge apparatus and an image forming apparatus.
FIG. 10 is a perspective view showing a main part of an ink jet recording apparatus according to an embodiment of the present invention, and FIG. 11 is a side sectional view of a mechanism part of the ink jet recording apparatus.
The ink jet recording apparatus according to this embodiment includes a carriage 33 that can move in the main scanning direction inside the recording apparatus main body 21, a recording head 34 that includes the ink jet head according to the present invention mounted on the carriage, and ink that supplies ink to the recording head. The printing mechanism 22 including the cartridge 35 is accommodated.
In addition, a sheet feeding cassette (or a sheet feeding tray) 24 on which a large number of sheets 23 can be stacked from the front side is detachably attached to the lower part of the recording apparatus main body 21, and the sheets 23 are manually inserted. The manual feed tray 25 for feeding paper can be opened up, the paper 23 fed from the paper feed cassette 24 or the manual feed tray 25 is taken in, and a required image is recorded by the printing mechanism unit 22. The paper is discharged to a paper discharge tray 26 attached to the.
[0020]
The printing mechanism 22 holds the carriage 33 slidably in the main scanning direction (in the direction perpendicular to the paper in FIG. 11) with a main guide rod 31 and a sub guide rod 32 which are guide members horizontally mounted on left and right side plates (not shown). To do. The carriage 33 is provided with a plurality of recording heads 34 composed of inkjet heads that are droplet discharge heads according to the present invention that discharge ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). Are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward. Further, the carriage 33 is mounted with replaceable ink cartridges 35 for supplying inks of the respective colors to the recording head 34. The ink cartridge 35 has an atmosphere port communicating with the atmosphere above, a supply port for supplying ink to the recording head 34 below, and a porous body filled with ink inside, and a porous capillary tube. The ink supplied to the recording head 34 by the force is maintained at a slight negative pressure.
Further, although the recording heads of the respective colors are used as the recording heads 34 in this embodiment, one recording head having nozzles for ejecting ink droplets of the respective colors may be used.
[0021]
Furthermore, the ink jet head used as the recording head 34 is a piezoelectric type that pressurizes ink through a vibration plate that forms a liquid chamber wall surface with an electromechanical conversion element such as a piezoelectric element, or a bubble is generated by a heating resistor to generate ink. A bubble type that pressurizes, or an electrostatic type that pressurizes ink by displacing the diaphragm with an electrostatic force between the diaphragm that forms the wall surface of the ink flow path and the electrode facing it can be used. In this embodiment, a piezo ink jet head is used.
[0022]
Here, the carriage 33 is slidably fitted to the main guide rod 31 on the rear side (downstream side in the paper conveyance direction), and is slidably mounted on the sub guide rod 32 on the front side (upstream side in the paper conveyance direction). It is location. In order to move and scan the carriage 33 in the main scanning direction, a timing belt 40 is stretched between a driving pulley 38 and a driven pulley 39 that are rotationally driven by a main scanning motor 37, and the timing belt 40 is moved to the carriage 33. The carriage 33 is driven to reciprocate by forward and reverse rotation of the main scanning motor 37.
[0023]
On the other hand, in order to convey the paper 23 set in the paper feed cassette 24 to the lower side of the recording head 34, the paper feed roller 41 and the friction pad 42 for separating and feeding the paper 23 from the paper feed cassette 24 and the paper 23 are guided. The guide member 43 to be transported, the transport roller 44 for reversing and transporting the fed paper 23, the transport roller 45 pressed against the peripheral surface of the transport roller 44, and the feed angle of the paper 23 from the transport roller 44 are defined. A tip roller 46 is provided. The transport roller 44 is rotationally driven by a sub-scanning motor 47 through a gear train. A printing receiving member 49 is provided as a paper guide member for guiding the paper 23 fed from the transport roller 44 below the recording head 34 corresponding to the range of movement of the carriage 33 in the main scanning direction. A conveyance roller 51 and a spur 52 that are rotationally driven to send the paper 23 in the paper discharge direction are provided on the downstream side of the printing receiving member 49 in the paper conveyance direction, and the paper 23 is further delivered to the paper discharge tray 26. A roller 53 and a spur 54, and guide members 55 and 56 that form a paper discharge path are disposed.
[0024]
At the time of recording, the recording head 34 is driven according to the image signal while moving the carriage 33, thereby ejecting ink onto the stopped paper 23 to record one line. Record the line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 23 reaches the recording area, the recording operation is terminated and the paper 23 is discharged. In this case, the inkjet head according to the present invention constituting the recording head 34 has improved controllability of ink droplet ejection and suppressed characteristic fluctuations, so that an image with high image quality can be recorded stably.
[0025]
Further, a recovery device 57 for recovering defective ejection of the recording head 34 is disposed at a position outside the recording area on the right end side in the movement direction of the carriage 33. The recovery device 57 has a cap unit, a suction unit, and a cleaning unit. The carriage 33 is moved to the recovery device 57 side during printing standby, and the recording head 34 is capped by the capping unit, and the ejection port portion is kept in a wet state to prevent ejection failure due to ink drying. Further, by ejecting ink that is not related to recording during recording or the like, the ink viscosity of all the ejection ports is made constant and stable ejection performance is maintained.
When ejection failure occurs, the ejection port of the recording head 34 is sealed with a capping unit, bubbles are sucked out together with ink from the ejection port with a suction unit through a tube, and ink or dust adhering to the ejection port surface is cleaned. It is removed by the means and the ejection failure is recovered. The sucked ink is discharged into a waste ink reservoir (not shown) installed at the lower part of the main body and absorbed and held by an ink absorber inside the waste ink reservoir.
[0026]
【The invention's effect】
The present invention, vibration by forming a film thickness correction pattern for equalizing the thickness on the dynamic plate, it is possible to reduce the thickness deviation amount of the total thickness of the vibration plate, the droplets having a uniform one indicia copy properties A discharge device can be obtained.
[0027]
The present invention also electroforming by forming a plurality of groove patterns in the plating thin film portion, it is possible to increase the thickness of the plating total film thickness of the thin portion by concentrating the electric field of the groove, uniform one indicia copy properties Ru can be obtained droplet discharge device having a.
[0028]
In addition, the present invention increases the film thickness of the ink supply port by individually providing the ink supply ports formed on the vibration plate formed by electroforming plating in correspondence with the individual flow paths. the thickness and can be approximately equal, it is possible to obtain an ink jet head having a uniform one indicia copy properties.
Further, according to the present invention , the length of the ink supply port in the direction perpendicular to the arrangement direction is set to be three times or more the arrangement pitch, so that the escape of the electric field to the outer peripheral portion can be suppressed, and the increase in the thickness is effective. Can be implemented.
Further, the image forming apparatus of the present invention can be uniformly printed by mounting the droplet discharge apparatus of the present invention, and can form a high-quality image.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a diaphragm according to a first embodiment used in an ink jet head of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA of FIG.
FIG. 3 is a manufacturing process diagram showing an embodiment of a manufacturing method of a diaphragm used in an inkjet head.
FIG. 4 is a schematic plan view showing a diaphragm of a second embodiment used in the ink jet head of the present invention.
FIG. 5 is a schematic plan view showing a diaphragm of a third embodiment used in the inkjet head of the present invention.
FIG. 6 is a schematic plan view showing a diaphragm according to a fourth embodiment used in the ink jet head of the present invention.
FIG. 7 is a schematic plan view showing a diaphragm of a fifth embodiment used in the ink jet head of the present invention.
FIG. 8 is a schematic plan view showing a diaphragm according to a sixth embodiment used in the ink jet head of the present invention.
FIG. 9 is a schematic plan view showing a diaphragm of a seventh embodiment used in the ink jet head of the present invention.
FIG. 10 is a perspective view showing a main part of an ink jet recording apparatus according to an embodiment of the present invention.
11 is a side sectional view of a mechanism portion of the ink jet recording apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Diaphragm, 2 ... Vibration part, 3 ... Joint part, 4 ... Ink supply port, 5 ... Alignment mark, 6 ... Pattern removal part, 7 ... Actuator joining position, 8 ... Groove pattern, 11 ... Conductive substrate, 12 DESCRIPTION OF SYMBOLS: Resist, 13 ... Thin film, 14 ... Resist, 15 ... Thick part, 21 ... Recording apparatus main body, 22 ... Printing mechanism part, 23 ... Paper, 24 ... Paper feed cassette, 25 ... Manual feed tray, 26 ... Paper discharge tray, DESCRIPTION OF SYMBOLS 31 ... Main guide rod, 32 ... Sub guide rod, 33 ... Carriage, 34 ... Recording head, 35 ... Ink cartridge, 37 ... Main scanning motor, 38 ... Drive pulley, 39 ... Drive pulley, 40 ... Timing belt, 41 ... Feed Paper roller, 42: Friction pad, 43: Guide member, 44 ... Conveying roller, 45 ... Conveying roller, 46 ... End roller, 47 ... Sub-scanning motor, 49 ... Printing receiving member, 5 ... conveying rollers, 52, 54 ... spur, 53 ... discharge rollers, 55, 56 ... guide member, 57 ... recovery device.

Claims (6)

In a droplet discharge device having a vibration plate formed by electroforming plating and having a vibration portion region formed of a fine pattern, the vibration portion region is a rectangular region, and the vibration plate is the vibration portion. A droplet discharge device having a plurality of groove patterns only in diagonal regions on the outer periphery of the region.   The liquid droplet ejection apparatus according to claim 1, wherein the fine pattern includes a plurality of vibrating portion rows. 3. The droplet discharge device according to claim 1, wherein the diagonal region is located at an outer peripheral portion in an arrangement direction of a vibrating portion row of an ink supply port provided in the vibration plate.   The droplet discharge device according to claim 3, wherein the ink supply port is individually provided corresponding to a vibration part in the vibration part region.   The ink supply ports are arranged at the same pitch in the same direction as the arrangement direction of the vibration unit rows, and the width in the direction perpendicular to the arrangement direction is three times or more the width in the arrangement direction. Item 5. The droplet discharge device according to Item 4.   An image forming apparatus comprising the droplet discharge device according to claim 1.

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