JP2002254629A - Ink jet head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized and inexpensive ink jet head excellent in a printing quality by preventing mal-functioning of drive elements. SOLUTION: In the ink jet head, driver ICs 31, 32 as the plural drive elements to apply a voltage are provided on a printed board 13, and a power source line to input the drive voltage for operating the plural driver ICs 31, 32 is formed on the printed board 13 for the respective driver ICs 31, 32 as power source line patterns 35, 26. Thus, a voltage drop caused by the resistance of the power source line patterns 35, 36 formed on the printed board 13 is suppressed to supply a proper operating voltage to respective plural driver ICs 31, 32, for improving the print quality by preventing the mal-functioning of the driver ICs 31, 32, and making the ink jet head small size and inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink-jet head, and more particularly, to an ink-jet head which discharges ink droplets only when recording is required and attaches the ink droplets to a recording paper.

[0002]

2. Description of the Related Art The non-impact recording method has attracted attention for office use and the like because noise generation during recording is negligibly small. Among the non-impact recording methods, the so-called ink jet recording method, which is capable of high-speed recording and capable of recording on so-called plain paper without requiring a special fixing process, is an extremely powerful method. Has been proposed and has already been commercialized and put to practical use.

In such an ink jet recording method, recording is performed by flying small droplets of a recording liquid called so-called ink and attaching the droplets to a recording medium. Depending on the control method for controlling the flight direction of the aircraft, it is roughly classified into several types.

In particular, in recent years, as a method capable of achieving high density and high integration using a silicon substrate, Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 3-29 is disclosed in Japanese Patent Application Publication No.
There is a technique described in Japanese Patent No. 3141. This technology is
This is a recording method (electrostatic ink jet recording apparatus) in which a voltage is applied to the electrode between the substrate and the diaphragm and the diaphragm is bent by electrostatic force to eject ink, and the head forming method is to etch the silicon substrate. Thus, a liquid chamber and a diaphragm are formed.

Further, in the case of an electrostatic ink jet head, a vibrating plate is provided in a part of an ink liquid chamber, and a counter electrode is provided in a direction different from that of the ink liquid chamber. There is one that realizes stable driving of a plate (see JP-A-6-50601). That is, in this electrostatic inkjet head, a common electrode is formed on a vibration plate, an individual electrode facing the common electrode is formed on an electrode substrate, and both electrodes are arranged with high precision and a minute gap. In addition, by using a substrate such as silicon which is easily etched as an electrode substrate, a groove for forming a minute gap and an individual electrode located at the bottom thereof can be easily formed. The size of the minute gap is several μm or less. This is because if the gap is large, the voltage for deforming the diaphragm becomes very large. In order to drive at least 100 V or less, the voltage needs to be several μm or less.

Conventionally, as a method for mounting a driver IC of an ink jet recording apparatus, a character or bit image is printed by selectively distorting a piezoelectric element according to a print command to contract an ink chamber and causing ink to fly from a nozzle. An ink jet printer comprising a head data signal generating circuit, a high voltage power supply for driving the head, a charging control circuit for applying a high voltage to the piezoelectric element, and an ink jet head driving circuit, wherein the ink jet head driving circuit is provided near the ink jet head. There has been proposed an ink jet printer in which the charge control circuit is mounted on a main body substrate (see Japanese Patent Application Laid-Open No. Hei 5-116282).

[0007]

However, the ink jet head has been miniaturized to the point where the pitch of the input pads of the driver ICs (driving elements) is 100 μm or less, and has been put to practical use. However, the wiring pattern becomes thinner, the resistance of the wiring pattern becomes higher, and there is a possibility that a malfunction of the driver IC may occur.

However, in the prior art described in the above publication,
Although the wiring pattern can be shortened, no consideration is given to the operation failure of the driver IC due to the thinning of the wiring pattern and the increase in its resistance, and there is a demand for technical development for this problem.

Therefore, the invention according to claim 1 is provided on a diaphragm substrate which forms a part of a pressurized liquid chamber communicating with a nozzle formed on a nozzle substrate, and applies pressure to ink in each pressurized liquid chamber. A plurality of driving elements for applying a voltage are provided on a printed circuit board between a plurality of diaphragms to which voltage is applied and an individual electrode formed with a minute gap at a position facing the diaphragm on the electrode substrate. By providing a power supply line for inputting a drive voltage for operating a plurality of drive elements on the printed circuit board individually for each drive element, a voltage drop due to a pattern resistance of the power supply line formed on the printed circuit board is suppressed, An object of the present invention is to provide a small and inexpensive inkjet head that supplies good operating quality by supplying an appropriate operating voltage to each of a plurality of drive elements and preventing unnecessary operation of the drive elements. To have.

According to a second aspect of the present invention, a printed circuit board includes:
A power supply input terminal for inputting a drive voltage for operating the drive element from the outside is provided in common for the plurality of drive elements, and the drive voltage is supplied to each of the plurality of drive elements from the common power supply input terminal through an individual power supply line. By reducing the number of power supply input terminals, suppressing the voltage drop due to the pattern resistance of the power supply line formed on the printed circuit board, supplying an appropriate operating voltage to each of the plurality of drive elements, An object of the present invention is to provide an ink jet head which prevents unnecessary operation, has good printing quality, and is smaller and cheaper.

According to a third aspect of the present invention, a pressure plate is formed on a diaphragm substrate forming a part of a pressurized liquid chamber communicating with a nozzle formed on a nozzle substrate, and a pressure is applied to ink in each pressurized liquid chamber. A plurality of driving elements for applying a driving pulse are provided on the printed circuit board between the plurality of diaphragms and the individual electrodes formed on the electrode substrate at a position opposed to the diaphragm with a small gap, and the plurality of A signal line for inputting a drive pulse for operating the drive element is provided on the printed circuit board individually for each drive element, thereby suppressing a voltage drop of the drive pulse due to a pattern resistance of the signal line formed on the printed circuit board. In this way, an appropriate driving pulse is supplied to each of a plurality of driving elements to prevent unnecessary operation of the driving elements, thereby providing a small and inexpensive ink jet head having good printing quality. It is aimed at.

According to a fourth aspect of the present invention, a printed circuit board includes:
A drive pulse input terminal for inputting drive pulses from outside
By providing a drive pulse to each of the plurality of drive elements by providing a common signal to the plurality of drive elements and supplying a drive pulse to each of the plurality of drive elements via an individual signal line from the common drive pulse input terminal, while reducing the number of drive pulse input terminals Suppresses the voltage drop of the drive pulse due to the pattern resistance of the signal line formed on the printed circuit board, supplies an appropriate drive pulse to each of a plurality of drive elements, prevents unnecessary operation of the drive elements, and improves print quality Accordingly, it is an object of the present invention to provide a more compact and inexpensive inkjet head.

[0013]

According to the first aspect of the present invention, there is provided an ink jet head having a nozzle substrate having at least a plurality of nozzles for discharging ink, a pressurized liquid chamber communicating with the nozzle, and a pressurized liquid chamber. A vibrating plate substrate on which a plurality of vibrating plates are formed to form a part of the liquid chamber and apply pressure to the ink in each of the pressurized liquid chambers, and individual electrodes are formed with a minute gap at a position facing the vibrating plate Electrode substrate, and a printed circuit board provided with a drive element for applying a voltage to the individual electrode, an inkjet head comprising:
The printed board achieves the above object by providing a plurality of drive elements and separately providing power supply lines for inputting drive voltages for operating the plurality of drive elements.

According to the above construction, the plurality of pressure plates formed on the vibration plate substrate forming a part of the pressurized liquid chamber communicating with the nozzle formed on the nozzle substrate and applying pressure to the ink in each pressurized liquid chamber are formed. A plurality of drive elements for applying a voltage are provided on a printed circuit board between a diaphragm and an individual electrode formed with a minute gap at a position facing the diaphragm on the electrode substrate, and the plurality of drive elements are provided. The power supply line for inputting the drive voltage for operating the drive is individually provided on the printed circuit board for each drive element. Appropriate operating voltage can be supplied to each element, preventing unnecessary operation of the drive element, improving print quality, and making the inkjet head small and inexpensive. It can be a thing.

In this case, for example, as described in claim 2, in the printed circuit board, a power supply input terminal for externally inputting a drive voltage for operating the drive element is shared by the plurality of drive elements. The drive voltage may be provided from the common power supply input terminal to each of the plurality of drive elements via the individual power supply line.

According to the above arrangement, a power supply input terminal for externally inputting a drive voltage for operating the drive element is provided on the printed circuit board in common for the plurality of drive elements, and an individual power supply is provided from the common power supply input terminal. Since a drive voltage is supplied to each of the plurality of drive elements by a line, the number of power supply input terminals is reduced, and a voltage drop due to a pattern resistance of a power supply line formed on a printed circuit board is suppressed, and each of the plurality of drive elements is controlled. In addition, it is possible to supply an appropriate operating voltage, prevent the operation of the driving element from being unnecessary, improve the printing quality, and further reduce the size and cost of the inkjet head.

According to a third aspect of the present invention, there is provided an ink jet head including a nozzle substrate having at least a plurality of nozzles for discharging ink, a pressurized liquid chamber communicating with the nozzle, and a part of the pressurized liquid chamber. A diaphragm substrate formed with a plurality of diaphragms for applying pressure to ink in each of the pressurized liquid chambers, and an electrode substrate on which individual electrodes are formed with a small gap at a position facing the diaphragm, A printed circuit board provided with a drive element for applying a drive pulse to the individual electrode, wherein the printed board is provided with a plurality of drive elements, and the drive pulse is input to the plurality of drive elements. The above-described object is achieved by providing the signal lines individually.

According to the above arrangement, a plurality of pressure liquid chambers formed on the diaphragm substrate forming a part of the pressurized liquid chamber communicating with the nozzle formed on the nozzle substrate and applying pressure to the ink in each pressurized liquid chamber. A plurality of drive elements for applying a drive pulse are provided on the printed circuit board between the diaphragm and an individual electrode formed on the electrode substrate with a small gap at a position facing the diaphragm, and the plurality of drive elements are provided. Since signal lines for inputting drive pulses for operating the elements are individually provided on the printed circuit board for each drive element, the voltage drop of the drive pulse due to the pattern resistance of the signal lines formed on the printed circuit board is suppressed. In addition, it is possible to supply an appropriate drive pulse to each of the plurality of drive elements, thereby preventing unnecessary operation of the drive elements, improving print quality, and improving ink jet printing. Toheddo the can be made compact and inexpensive.

In this case, for example, in the printed circuit board, a drive pulse input terminal for inputting the drive pulse from outside is provided commonly to the plurality of drive elements. The drive pulse may be supplied from the common drive pulse input terminal to each of the plurality of drive elements via the individual signal line.

According to the above configuration, a drive pulse input terminal for inputting a drive pulse from the outside is provided in common for a plurality of drive elements on a printed circuit board, and individual signal lines are provided from the common drive pulse input terminal. Since a drive pulse is supplied to each of the plurality of drive elements, the number of drive pulse input terminals is reduced, and a voltage drop of the drive pulse due to a pattern resistance of a signal line formed on a printed circuit board is suppressed, thereby enabling a plurality of drive pulses. Appropriate driving pulses can be supplied to the respective elements, and the unnecessary operation of the driving elements can be prevented, so that the printing quality can be improved and the inkjet head can be made smaller and less expensive.

[0021]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 3 show a first embodiment of the ink jet head of the present invention. FIG. 1 shows an electrostatic head to which the first embodiment of the ink jet head of the present invention is applied. FIG. 2 is an exploded perspective view of the inkjet head 1 of FIG. 1, and FIG. 2 is a sectional view of a main part of the inkjet head 1 of FIG.

In FIG. 1 and FIG. 2, the ink jet head 1 has a frame 4 to which a filter 3 is heat-sealed and bonded to a joint 2 for supplying ink from an ink supply tank or an ink cartridge. As shown in FIG. 2, an actuator unit 7 having a nozzle substrate 6 bonded thereto is bonded on the electrostatic actuator 5.

As shown in FIG. 2, the electrostatic actuator 5 has an electrode substrate 8, a vibrating plate substrate 9, and a liquid chamber substrate 10 laminated in this order, and the nozzle substrate 6 is bonded onto the liquid chamber substrate 10 with an adhesive. ing.

The diaphragm substrate 9 is formed with a desired thickness and a fine pattern with high precision by etching a metal such as SUS or Si. 9 itself can also be used as a common electrode. When an insulating material such as glass is used as the material of the diaphragm substrate 9, a metal such as Al, Cu, Cr, Ni, or Au is formed on the surface by a method such as evaporation or sputtering. Thus, a common electrode can be formed. The diaphragm substrate 9 has a concave portion in which the diaphragm 11 is formed on the bottom surface by a known method such as mechanical processing such as partial polishing or electroforming such as etching.

The electrode substrate 8 forms a gap of a desired height by etching a metal such as SUS or Si or the like, and further forms an insulating layer in the gap with an insulating material such as resin or SiO _2. Formed, and the individual electrodes 12
An electrode material such as Ni, Al, Ti / Pt, and Cu is formed into a desired thickness by a film forming technique such as sputtering, CVD, or vapor deposition. After that, in the electrode substrate 8, a photoresist is formed and etched, so that the individual electrodes 12 are formed only in the gap.

Accordingly, the electrode substrate 8 is made of a conductor or a semiconductor and has a conductive substrate, an insulating layer formed thereon, and an individual electrode 12 formed of a conductive material on the insulating layer. Consists of Further, by extracting and fixing a part of the common electrode in a region other than the common electrode forming portion on the surface of the electrode substrate 8, the individual electrode 12 is formed.
And the common electrode can be formed in substantially the same plane, and connection to a printed board (printed board for driving the head) 13 described later becomes easy.

The diaphragm substrate 9 and the electrode substrate 8 are joined by a direct joining method such as an adhesive or anodic joining.

Further, on the individual electrodes 12 of the electrode substrate 8, for the purpose of preventing the electrodes from being damaged by a short circuit or electric discharge, a SiO 2 portion except for a connection portion with the printed substrate 13 is formed.
_An insulating layer made of ₂ or a resist material may be formed.

The liquid chamber substrate 10 is made of glass, metal, or
The liquid chamber substrate 10 is formed of Si
And a common liquid chamber 15 for supplying ink in communication with each of the pressurized liquid chambers 14.
And a liquid chamber substrate 1 between the common liquid chamber 15 and each pressurized liquid chamber 14.
The fluid resistance 16 formed by joining the nozzle substrate 6 to the nozzle substrate 6 is formed. Liquid chamber substrate 10 and diaphragm substrate 9
Are joined using an adhesive or a dry film.

The nozzle substrate 6 is bonded to the liquid chamber substrate 10 with an adhesive, and the nozzle substrate 6 is formed with a nozzle hole 17 communicating with each pressurized liquid chamber 14. The nozzle substrate 6 discharges the ink in the pressurized liquid chamber 14 from the nozzle hole 17 onto a recording medium such as paper. The surface on the ink ejection side (ejection surface) of the nozzle substrate 6 is subjected to a water-repellent treatment by a known method (plating, coating with a water-repellent agent, or the like) in order to ensure water repellency with the ink.

In the frame 4, an ink flow path 18 communicating with the common liquid chamber 15 is formed, and insertion grooves 19 are formed on both side surfaces thereof. The ink is supplied from the ink cartridge through the joint 2, and the ink flow path 18 transfers the supplied ink to the electrostatic actuator 5.
Is supplied to the common liquid chamber 15.

The insertion groove 19 of the frame 4 has a driver I
A printed circuit board 13 on which C20 is mounted by wire bonding is inserted, and the printed circuit board 13 is connected to the individual electrodes 12. As the printed board 13, a plate-shaped printed board made of glass epoxy resin, phenol resin, or the like, or a film-shaped printed board (FPC) made of polyimide resin, PET resin, or the like is used. An electrode lead for applying a voltage to 12 is formed.

As a method of electrically connecting the electrode leads on the printed circuit board 13 to the individual electrodes 12 and the electrode pads of the common electrode, for example, a method of thermocompression bonding of solder or a method of thermocompression bonding with an anisotropic conductive adhesive Alternatively, a method in which electrodes are pressed against each other, a wire bonding method, or the like can be used. The wire bonding method is a connection method that has low connection resistance and high reliability because the electrodes are directly connected to each other with a metal wire. The method of thermocompression bonding of solder, the method of thermocompression bonding with an anisotropic conductive adhesive, and the method of press-contacting between electrodes can be performed easily at low cost because the connection between multiple electrodes can be performed at once. This is an excellent method in that there is. Furthermore, among these, the method of thermocompression bonding between the FPC and the electrode substrate 8 using solder or an anisotropic conductive film, since the substrates are bonded after the compression, electric connection and fixing of the FPC are performed simultaneously. This is an excellent connection method in that a new bonding step for bonding is not required to improve reliability so that a connection portion is not removed during processing, assembly, printing operation, or the like.

The individual electrode 1 is provided on the outer portion of the diaphragm 11 between the electrostatic actuator 5 and the nozzle substrate 6.
An adhesive 21 for sealing a diaphragm gap is applied to seal a pressure chamber between the diaphragm 2 and the diaphragm 11, and a nozzle is provided between a corner of the nozzle substrate 6 and the frame 4. An adhesive 22 for sealing the plate is applied.

FIG. 3 shows an example in which the printed circuit board 13 is formed by FPC. On the printed circuit board 13, two driver ICs (driving elements) are used as the driver ICs 20.
31 and 32 are mounted. On the printed circuit board 13,
An input terminal group 33 and an output terminal group 34 are formed. The output terminal group 34 is connected to the individual electrodes 12 of the actuator 5 and to output terminals of the driver ICs 31 and 32. Drive pulses are supplied from the output terminals of the driver ICs 31 and 32 to the individual electrodes 12 from the output terminal group 34 in accordance with the image information. Driver IC 31, 3
As the mounting method 2, general IC (Integr.) Such as TAB method, wire bonding method, flip chip mounting method, etc.
(ated circuit: integrated circuit) can be used. The input terminals of the driver ICs 31 and 32 are connected to the input terminal group 33. The input terminal group 33 includes a power supply terminal Vcc and signal terminals S1 to S4. The input terminals of the driver ICs 31 and 32 include a power supply (usually 5 V or 3.3 V) for driving circuits in the driver ICs 31 and 32 and a ground terminal. There are terminals for signals such as a clock, data, and a latch for inputting data.

By the way, in order to increase the printing speed, 1
Nozzle 17 formed by one inkjet head 1
It is effective to increase the number. On the other hand, driver I
For C31 and C32, if the number of channels is too large, the size of the driver ICs 31 and 32 becomes large, and it becomes impossible to effectively remove the driver ICs 31 and 32 from one silicon wafer, or the yield of the driver ICs 31 and 32 becomes low. The problem of worsening occurs. Therefore, there is an optimum value for the size of the driver ICs 31 and 32. Usually, the length is about 14 mm or less, preferably
It is about 10 mm. Also, the pitch of the terminals (pads) of the driver ICs 31 and 32 is usually 70 to 80 μm even if it is narrow due to mounting restrictions when connecting to the printed circuit board 13.
Up to about m is the limit in mass production. Therefore, within the size of such driver ICs 31 and 32, 120 to 140 channels (when the size is 10 mm)
Can only take a degree. As a result, if the number of nozzles 17 exceeds this number, the driver IC 3
Providing a plurality of 1 and 32 is necessary in terms of improving yield and reducing costs.

However, when a plurality of driver ICs 31 and 32 are provided, the number of input terminals of the driver ICs 31 and 32 increases accordingly. Therefore, the printed circuit board 13
The number of input signal terminals increases, and a controller board formed of an external substrate (microprocessor, ROM, RAM, I / O element, etc. is generally used.
The detailed description is omitted), the number of poles of a connector such as FPC or FFC (referred to as a flexible flat cable) or the like, which is a printed circuit board 13, increases cost. As a result, as shown in FIG.
The connection between the input terminal 3 and the driver ICs 31 and 32 is as follows.
Only one driver IC 31 is used, and the other driver IC 32 is connected from the driver IC 31.

At this time, for the power supply lines for driving the driver ICs 31 and 32, the input terminal Vcc of the printed circuit board 13 is provided, and the power supply line patterns 35 and 36 are directly provided.
Connect with. This is because the input pads of the driver ICs 31 and 32 are thin and the wiring pattern of the FPC is also thin. Therefore, when a power supply line is connected to the driver IC 32 via the driver IC 31, a voltage drop due to the resistance of the FPC pattern occurs, and This is to prevent the actual voltage applied to the power supply pad from decreasing. Further, the driver ICs 31 and 32 are set to 5 V ± 5% or 3.3 V ± 5% as a normal power supply, and the voltage supplied to the printed circuit board 13 is controlled by a microprocessor, ROM, RAM, etc. of the main body. In order to standardize the IC of
5V ± 5% or 3.3V ± 5% is supplied. Therefore, when the substantial voltage applied to the driver ICs 31 and 32 decreases, the driver ICs 31 and 32 do not operate normally.

Therefore, in the ink jet head 1 of this embodiment, the power supply terminals Vcc of the input terminal group 33 of the printed circuit board 13 and the power supply terminals of the driver ICs 31 and 32 are directly connected by the power supply line patterns 35 and 36. .

Therefore, the FP which is the printed circuit board 13
There is no voltage drop due to the pattern resistance of C, and both driver ICs 31 and 32 can operate normally.

Next, the operation of the present embodiment will be described. First, the ink jet head 1 fills the pressurized liquid chamber 14 in the entire ink supply channel with the ink supplied to the ink supply port through the ink flow path 18, the common liquid chamber 15, and the fluid resistance 16. When the individual electrodes 12 are individually energized, an electrostatic force is generated between the individual electrodes 12 and the diaphragm 11, and the diaphragm 11
Displace to the side. When the diaphragm 11 is displaced, the ink flows from the common liquid chamber 15 through the fluid resistance 16 into the pressurized liquid chamber 14, and the volume of the pressurized liquid chamber 14 increases. Here, when the pulse voltage applied to the individual electrode 12 is released, the electrostatic force between the individual electrode 12 and the diaphragm 11 disappears, and the diaphragm 11 returns to the original state.

The pressurized liquid chamber 1 due to the elastic force of the diaphragm 11
With the pressure increase of 4, ink is ejected from the nozzle holes 17.

In the ink jet head 1 according to the present embodiment, the driver ICs 31 and 32, which are a plurality of drive elements for applying a voltage, are provided on the printed circuit board 13, and a drive voltage for operating the driver ICs 31 and 32 is input. Power supply lines to be connected to the respective driver ICs 31 and 32
The power supply line patterns 35 and 36 are individually formed on the printed circuit board 13 each time.

Accordingly, it is possible to suppress a voltage drop due to the pattern resistance of the power supply line patterns 35 and 36, which are power supply lines formed on the printed circuit board 13, and supply an appropriate operating voltage to each of the plurality of driver ICs 31 and 32. This makes it possible to prevent unnecessary operation of the driver ICs 31 and 32, improve print quality, and reduce the size and cost of the inkjet head 1.

Example 1 An ink jet head having the following specifications was actually manufactured. A printed circuit board 30 made of FPC as shown in FIG. 3 was connected to this inkjet head, and patterns of driver ICs 31 and 32 of FPC were formed with a width of 40 μm and a pitch of 80 μm.

Specification of head Number of nozzles: 192 nozzles Array density of nozzles (= array density of individual electrodes): 300d
pi Diaphragm plate size: width 140 μm, length 2 mm, thickness 2 μm Common electrode width: 0.5 mm Individual electrode width: 130 μm Gap: 0.5 μm Specification of anisotropic conductive film Thickness: 25 μm, particle diameter: 5 μm Driving condition Driving voltage: 30 V Pulse width: 10 μsec Continuous driving frequency: 16 kHz Specification of driver IC Number: 96 channels / two used Pad pitch: 80 μm Chip size: 2 mm × 11 mm × 0.4 mm When driven under the following driving conditions, good ink ejection with little variation in ejection characteristics from all nozzles was observed, and a high-quality printed image was obtained. In addition, when the drive pulses were observed at the output terminals of the driver ICs 31 and 32 with an oscilloscope, variations in rise time and fall time between channels were small.

For comparison, the power supply line of the FPC is also input to the driver IC 31 and input to the driver IC 32 via the driver IC 31. As a result, the output waveform of the driving pulse of the driver IC 32 is delayed. This was revealed by oscilloscope observation.

In the present embodiment, a so-called side shooter type ink jet head has been described as an example, but it is needless to say that the present invention can be similarly applied to an edge shooter type ink jet head.

Further, in this embodiment, the case of flip-chip mounting is exemplified as a mounting method of the driver IC. However, the problem of the capacitance due to the pattern similarly occurs in any mounting method. Can be applied to

Further, in this embodiment, the driver IC
Is described, but the same can be applied to the case where the number of driver ICs is three or more, which is particularly effective since the length of the wiring pattern becomes longer.

FIG. 4 is a plan view of a printed circuit board 40 of an ink jet head to which the second embodiment of the ink jet head of the present invention is applied.

This embodiment is applied to the same ink jet head as that of the first embodiment. In the description of this embodiment, the same components are denoted by the same reference numerals. The detailed description will be omitted, and the description will be made using the reference numerals used in the first embodiment as needed, as necessary.

In FIG. 4, the printed circuit board 40 has an FP
The printed circuit board 40 has driver ICs (driver ICs) 41 and 42 mounted thereon. The printed circuit board 40 includes an input terminal group 43 and an output terminal group 44.
Are formed, and the output terminal group 44 is connected to the individual electrode 12 of the actuator 5 and the driver IC
41 and 42 are connected to output terminals. Driver IC
Drive pulses are supplied from the output terminals 41 and 42 to the individual electrodes 12 from the output terminal group 44 in accordance with image information.

The input terminal group 43 of the printed circuit board 40 includes
Only one power supply terminal Vcc is provided.
One driver IC 41, 42 has one of the input terminal groups 43
From one power supply terminal Vcc to each power supply line pattern 45, 4
At 6, power supply voltages are supplied.

The input terminal group 43 is provided with each input signal S
One signal input terminal S1 to S4 is provided for each of the signal input terminals S1 to S4 of the input terminal group 43.
4 is directly connected to one driver IC 41, and the other driver IC 42 receives an input signal via the driver IC 41.

Accordingly, the number of input terminals of the input terminal group 43 of the printed circuit board 40 can be reduced, and the number of poles of the connector and the number of FPC or FFC cores for connection to the main body are reduced, thereby reducing costs. be able to.

FIG. 5 is a plan view of a printed circuit board 50 of an ink jet head of an ink jet recording apparatus to which the third embodiment of the ink jet head of the present invention is applied.

This embodiment is applied to the same ink jet head as that of the first embodiment. In the description of this embodiment, the same components are denoted by the same reference numerals. The detailed description will be omitted, and the description will be made using the reference numerals used in the first embodiment as needed, as necessary.

In FIG. 5, the printed circuit board 50 is an FP
The printed circuit board 50 has driver ICs (driver ICs) 51 and 52 mounted thereon. The printed circuit board 50 has an input terminal group 53 and an output terminal group 54.
Are formed. The output terminal group 54 is connected to the individual electrodes 12 of the actuator 5 and the driver IC
51 and 52 are connected to output terminals. Driver IC
Drive pulses Vp are supplied from the output terminals 51 and 52 to the individual electrodes 12 from the output terminal group 54 in accordance with image information.

The input terminal group 53 of the printed circuit board 50 includes:
Two terminals for supplying the drive pulse Vp are provided to the driver ICs 51 and 52, and one signal input terminal S1 to S4 is provided for each input signal S1 to S4.

The drive pulse Vp of the input terminal group 53
Are connected to driver ICs 51 and 52 by drive pulse pattern lines 55 and 56, respectively. This is because the input pads of the driver ICs 51 and 52 are thin and the wiring pattern of the FPC, which is the printed circuit board 50, is also thin. This is to prevent the voltage of the driving pulse Vp actually applied to the driver ICs 51 and 52 from dropping due to the drop. Further, when the drive pulse Vp input to the driver ICs 51 and 52 decreases, the voltage of the drive pulse Vp supplied to the individual electrodes 12 of the actuator 5 decreases, and the displacement characteristics of the diaphragm 11 vary between the driver IC 51 and the driver IC 52. In this case, the ink ejection characteristics vary, and the print quality deteriorates.

Therefore, in this embodiment, the drive pulse Vp terminal of the input terminal group 53 of the printed circuit board 50 and the power supply terminals of the driver ICs 51 and 52 are directly connected by the drive pulse pattern lines 55 and 56. , FPC to prevent the voltage drop due to the pattern resistance,
Both C51 and C52 can perform a normal operation.

As described above, the input terminal group 53 is provided with one signal input terminal S1 to S4 for each of the input signals S1 to S4. S4 are directly connected to one driver IC 51, and the other driver ICs 52
An input signal is input via 51.

Next, the operation of the present embodiment will be described. In the inkjet head 1 of the present embodiment, first, the ink supplied to the ink supply port is filled in the pressurized liquid chamber 14 in the entire ink supply channel through the ink flow path 18, the common liquid chamber 15, and the fluid resistance 16, When the individual electrodes 12 are individually energized according to the image information, the individual electrodes 12
Electrostatic force is generated between the vibration plate 11 and the vibration plate 11.
Is displaced toward the individual electrode 12 side. When the diaphragm 11 is displaced, the ink flows from the common liquid chamber 15 through the fluid resistance 16 into the pressurized liquid chamber 14, and the volume of the pressurized liquid chamber 14 increases.
Here, when the pulse voltage applied to the individual electrode 12 is released, the electrostatic force between the individual electrode 12 and the diaphragm 11 disappears, and the diaphragm 11 returns to the original state.

The pressurized liquid chamber 1 due to the elastic force of the diaphragm 11
With the pressure increase of 4, ink is ejected from the nozzle holes 17.

In the ink jet head 1 according to the present embodiment, the driver ICs 51 and 52 which are a plurality of drive elements for applying the drive pulse Vp are provided on the printed circuit board 50, and the drive ICs for operating the driver ICs 51 and 52 are provided. Drive pulse pattern lines 55 and 56 as signal lines for inputting the pulse Vp
Each of the printed circuit boards 51 and 52 is individually formed.

Therefore, the driving pulse pattern lines 55 and 5 which are signal lines formed on the printed circuit board 50
6, a suitable drive pulse Vp can be supplied to each of the plurality of driver ICs 51 and 52 by suppressing the voltage drop of the drive pulse Vp due to the pattern resistance of the driver IC.
The operation quality of the inkjet head 1 can be improved by preventing unnecessary operations of the ink jet heads 51 and 52 and improving the print quality.

Example 2 An ink jet head having the following specifications was actually manufactured. A printed circuit board 50 made of FPC as shown in FIG. 5 was connected to the ink jet head, and patterns of driver ICs 51 and 52 of FPC were formed with a width of 40 μm and a pitch of 80 μm.

Specification of head Number of nozzles: 192 nozzles Array density of nozzles (= array density of individual electrodes): 300d
pi Diaphragm plate size: width 140 μm, length 2 mm, thickness 2 μm Common electrode width: 0.5 mm Individual electrode width: 130 μm Gap: 0.5 μm Specification of anisotropic conductive film Thickness: 25 μm, particle diameter: 5 μm Driving condition Driving voltage: 30 V Pulse width: 10 μsec Continuous driving frequency: 16 kHz Specification of driver IC Number: 96 channels / two used Pad pitch: 80 μm Chip size: 2 mm × 11 mm × 0.4 mm When driven under the following driving conditions, good ink ejection with little variation in ejection characteristics from all nozzles was observed, and a high-quality printed image was obtained. When the driving pulse was observed at the output terminals of the driver ICs 51 and 52 with an oscilloscope, the variation between the rise time and the fall time between the channels was small.

For comparison, the supply line of the driving pulse of the FPC is also input to the driver IC 51 and the driver IC 52
Observed by an oscilloscope, it was found that when the driver IC 51 was input via the driver IC 51, the output voltage of the drive pulse Vp of the driver IC 52 was lower than that of the driver IC 51.

In the present embodiment, a so-called side shooter type ink jet head has been described as an example, but the present invention can be applied to an edge shooter type ink jet head.

Further, in this embodiment, the case of flip-chip mounting is exemplified as a method of mounting the driver IC. However, in any mounting method, the problem of the capacitance due to the pattern similarly occurs. And can be similarly applied.

Further, in this embodiment, the driver IC
Is described, but the same can be applied to the case where the number of driver ICs is three or more, which is particularly effective since the length of the wiring pattern becomes longer.

FIG. 6 is a plan view of a printed circuit board 60 of an ink jet head of an ink jet recording apparatus to which the fourth embodiment of the ink jet head of the present invention is applied.

This embodiment is applied to the same ink jet head as that of the first embodiment. In the description of this embodiment, the same components are denoted by the same reference numerals. The detailed description will be omitted, and the description will be made using the reference numerals used in the first embodiment as needed, as necessary.

In FIG. 6, the printed circuit board 60 is an FP
The printed circuit board 60 has driver ICs (driver ICs) 61 and 62 mounted thereon. The printed circuit board 60 has an input terminal group 63 and an output terminal group 64.
Are formed, and the output terminal group 64 is connected to the individual electrode 12 of the actuator 5 and the driver IC
61 and 62 are connected to the output terminals. Driver IC
Drive pulses are supplied from the output terminals 61 and 62 to the individual electrodes 12 from the output terminal group 64 according to image information.

The input terminal group 63 of the printed circuit board 60 includes:
Only one terminal for one drive pulse Vp is provided.
One driver IC 61, 62 has one of the input terminal groups 63.
Drive pulses Vp are supplied from drive pulse terminals Vp on drive pulse pattern lines 65 and 66, respectively.

The input terminal group 63 is provided with each input signal S
One signal input terminal S1 to S4 is provided for each of the signal input terminals S1 to S4 of the input terminal group 63.
4 is directly connected to one driver IC 61 by drive pulse pattern lines 65 and 66, and is connected to another driver IC 61.
An input signal is input to 62 via the driver IC 61.

Therefore, the number of input terminals of the input terminal group 63 of the printed circuit board 60 can be reduced, and the number of connector poles and the number of FPC or FFC cores for connection to the main body are reduced, thereby reducing costs. be able to.

As described above, the invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the gist of the invention. It goes without saying that it is possible.

[0082]

According to the first aspect of the present invention, the ink jet head is formed on the diaphragm substrate which forms a part of the pressurized liquid chamber communicating with the nozzle formed on the nozzle substrate.
A plurality of diaphragms for applying pressure to the ink in each pressurized liquid chamber,
A plurality of drive elements for applying a voltage are provided on a printed circuit board between the electrode substrate and an individual electrode formed with a minute gap at a position facing the vibration plate, and a drive for operating the plurality of drive elements Power supply lines for inputting voltage are individually provided on the printed circuit board for each drive element, so voltage drops due to pattern resistance of the power supply line formed on the printed circuit board are suppressed, making it suitable for each of multiple drive elements It is possible to supply a high operating voltage, to prevent unnecessary operation of the driving element, to improve the printing quality, and to make the ink jet head small and inexpensive.

According to the second aspect of the present invention, the printed circuit board is provided with a power supply input terminal for externally inputting a drive voltage for operating the drive element, to the plurality of drive elements. Since the drive voltage is supplied from the power input terminal to each of the multiple drive elements via individual power lines, the number of power input terminals is reduced, and the voltage drop due to the pattern resistance of the power line formed on the printed circuit board is suppressed. In addition, it is possible to supply an appropriate operating voltage to each of the plurality of driving elements, to prevent unnecessary operation of the driving elements, to improve print quality, and to make the inkjet head more compact and inexpensive. can do.

According to the third aspect of the invention, the ink jet head is formed on the diaphragm substrate which forms a part of the pressurized liquid chamber communicating with the nozzle formed on the nozzle substrate. A plurality of driving elements for applying a driving pulse are applied to a printed circuit board between a plurality of vibration plates for applying pressure to ink and an individual electrode formed with a minute gap at a position facing the vibration plate on the electrode substrate. In addition, since a signal line for inputting a driving pulse for operating the plurality of driving elements is individually provided on the printed circuit board for each driving element, the driving pulse due to the pattern resistance of the signal line formed on the printed circuit board is provided. , And appropriate drive pulses can be supplied to each of the plurality of drive elements, thereby preventing unnecessary operation of the drive elements and improving print quality. Preparative it is, the ink jet head can be made compact and inexpensive.

According to the ink jet head of the present invention, a drive pulse input terminal for inputting a drive pulse from the outside is provided in common for a plurality of drive elements on the printed circuit board, and the common drive pulse input terminal is provided. Since drive pulses are supplied from terminals to individual drive lines via individual signal lines, while reducing the number of drive pulse input terminals,
By suppressing the voltage drop of the drive pulse due to the pattern resistance of the signal line formed on the printed circuit board, it is possible to supply an appropriate drive pulse to each of a plurality of drive elements, preventing unnecessary operation of the drive elements and printing. The quality can be improved, and the inkjet head can be made smaller and less expensive.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of an inkjet head to which an inkjet head according to a first embodiment of the present invention has been applied.

FIG. 2 is a front sectional view of a main part of the inkjet head of FIG. 1;

FIG. 3 is a schematic plan view of a printed board of the inkjet head of FIG. 1;

FIG. 4 is a schematic plan view of a printed circuit board of an inkjet head to which a second embodiment of the inkjet head according to the invention is applied.

FIG. 5 is a schematic plan view of a printed circuit board of an ink jet head to which a third embodiment of the ink jet head of the present invention is applied.

FIG. 6 is a schematic plan view of a printed circuit board of an inkjet head to which an inkjet head according to a fourth embodiment of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ink jet head 2 Joint part 3 Filter 4 Frame 5 Electrostatic actuator 6 Nozzle substrate 7 Actuator unit 8 Electrode substrate 9 Vibrating plate substrate 10 Liquid chamber substrate 11 Vibrating plate 12 Individual electrode 13 Printed circuit board 14 Pressurized liquid chamber 15 Common liquid chamber 16 Liquid resistance 17 Nozzle hole 18 Ink flow path 19 Insertion groove 20 Driver IC 21, 22 Adhesive 31, 32 Driver IC 33 Input terminal group 34 Output terminal group 40, 50, 60 Printed circuit boards 41, 42, 51, 52, 61, 62 Driver IC 43, 53, 63 Input terminal group 44, 54, 64 Output terminal group 35, 36, 45, 46 Power supply line pattern 55, 56, 65, 66 Drive pulse pattern line

Claims (4)

[Claims] A pressurized liquid chamber communicating with the nozzle; a pressurized liquid chamber communicating with the nozzle; and a part of the pressurized liquid chamber formed in each of the pressurized liquid chambers. A vibrating plate substrate on which a plurality of vibrating plates for applying pressure to ink are formed, an electrode substrate on which individual electrodes are formed with a small gap at a position facing the vibrating plate, and a drive for applying a voltage to the individual electrodes And a printed board provided with elements, wherein the printed board is provided with a plurality of drive elements, and a power supply line for inputting a drive voltage for operating the plurality of drive elements,
An ink jet head, which is provided individually. 2. The printed circuit board, wherein a power supply input terminal for externally inputting a drive voltage for operating the drive element is provided commonly to the plurality of drive elements. 2. The ink jet head according to claim 1, wherein the drive voltage is supplied to each of the plurality of drive elements by a separate power supply line. 3. A nozzle substrate on which a plurality of nozzles for discharging ink are formed, a pressurized liquid chamber communicating with the nozzle, and a part of the pressurized liquid chamber, wherein a part of the pressurized liquid chamber is formed. A diaphragm substrate on which a plurality of diaphragms for applying pressure to ink are formed, an electrode substrate on which individual electrodes are formed with a small gap at a position facing the diaphragm, and a drive pulse is applied to the individual electrodes. A printed circuit board provided with a driving element, and an ink jet head comprising: a plurality of driving elements provided on the printed circuit board; and a signal line for inputting the driving pulse to the plurality of driving elements.
An ink jet head, which is provided individually. 4. The printed circuit board, wherein a drive pulse input terminal for inputting the drive pulse from the outside is provided in common for the plurality of drive elements, and the individual drive pulse input terminals are provided from the common drive pulse input terminal. 4. The ink jet head according to claim 3, wherein the drive pulse is supplied to each of the plurality of drive elements via a signal line.