JP3514062B2 - Ink jet recording head - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a plurality of head units that are provided with pressure generating means in a partial region of a pressure generating chamber communicating with a nozzle opening and pressurize ink in the pressure generating chamber to generate ink droplets. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ink jet recording heads arranged in tandem, and more particularly to a wiring structure for supplying a print signal to each head unit.

[0002]

2. Description of the Related Art In order to support high-speed printing and high-density printing, it has been attempted to increase the number of nozzle openings per recording head, but an ink jet recording head handles a liquid called ink. Therefore, it is required to form a large number of nozzle openings and pressure generation chambers uniformly and with high accuracy, because they are sensitive to the influence of non-uniformity such as fluid resistance of the flow passages such as nozzle openings and pressure generation chambers. In addition, if a defect occurs even in one of the flow paths and one of the pressure generating means, the print quality is extremely deteriorated and it becomes useless as a recording head. Therefore, there is a problem that the manufacturing yield is extremely low. .

[0003]

In order to solve such a problem, a plurality of recording heads having a relatively small number of pressure generating means as a unit are arranged in a row and assembled, and a recording head having a large number of nozzle openings. Is being configured. According to this, the manufacturing yield is improved by the number of the pressure generating means of the unit, and as a result, the recording head having a large number of nozzle openings can be manufactured with a high yield.

On the other hand, a print signal for pressurizing ink in the pressure generating chamber of the recording head to eject ink droplets from the nozzle opening is supplied from an external drive circuit through a flexible cable. It is necessary to secure as many signal lines as the number of lines on the flexible cable. When the number of nozzle openings increases, the width of each signal line should be narrowed or the width of the flexible cable should be widened. It is necessary to suppress the signal attenuation due to the resistance.

According to the former, there is a problem that the resistance and electrostatic capacity of the signal line increase to cause a time delay in signal attenuation and pressurization of ink in the pressure generating chamber. There is a problem that a large size gap occurs between the two, making it difficult to connect the two. In order to solve such a problem, a semiconductor device for generating a print signal is built in a flexible cable, and a print signal for pressurizing ink in each pressure generating chamber is not sent from an external drive circuit, but a print data is generated. Has been put into practical use by sending a print signal and generating a print signal by the driving integrated device on the flexible cable. According to this, it is possible to supply a print signal for pressurizing the ink in each pressure generating chamber with a signal line that is extremely smaller than the number of nozzle openings. The mounting of such a semiconductor device for generating a print signal on a flexible cable is
The flexible cable is provided with a window consisting of a through hole slightly larger than the outer circumference of the semiconductor device, and the copper foil forming the conductive pattern of the flexible cable is exposed inside the window to form a tab. It is done by soldering with.

[0006]

Although this is a very convenient method when one semiconductor device can generate a print signal for pressurizing the ink in all the pressure generating chambers. Since the number of terminals of the semiconductor device for supplying a signal to the pressurizing means of each pressure generating chamber is as many as the number of nozzle openings, when the number of nozzle openings is very large, about several hundred, these terminals are It is necessary to enlarge the size of the case of the semiconductor device, in particular, the length of the nozzle openings in the arrangement direction, to secure a region for forming the terminals so that the semiconductor device can be arranged. However, in the case of constituting one semiconductor device to accommodate a plurality of chips in one case, on necessary to supply a signal to each chip, but that Do required signal supply pattern, the piezoelectric vibrators from the semiconductor device Since the print signal supply pattern to the flexible cable is formed, the flexible cable does not have a region for forming a signal transmission pattern,
In the semiconductor device, there is no choice but to take a method of wire-connecting chips to each other to transmit a print signal. Further, according to such a method, not only the semiconductor device is specialized and the cost is increased, but also the wire in the semiconductor device is thin, which causes a loss of power particularly when driving power is supplied. is there.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an ink jet capable of supplying a print signal and driving power without requiring special processing of a semiconductor device. Type recording head.

[0008]

In order to solve such a problem, in the present invention, a pressure generating chamber communicating with a nozzle opening, a pressure generating unit for pressurizing the pressure generating chamber, and a pressure generating unit are provided. and <br/> recording head unit example Bei a connecting terminal for supplying a print signal, a semiconductor device for printing signal generating for generating a print signal which drives the pressure generating means based on a print signal from an external driving hands stage the supplies print signal from an external drive unit to the semiconductor device, the ink jet type to be connected to the connection terminal printing signal generated by said semiconductor device comprising a signal supplying member for supplying to said pressure generating means records In the head, a conductive pattern extending in the arrangement direction of the pressure generating chambers is formed at the center of the surface of the recording head unit, and is supplied by the signal supply member . The print signal or the driving power is transmitted to another area apart from the input side through the conductive pattern.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The details of the present invention will be described below with reference to illustrated embodiments. 1A and 1B show the main body of the ink jet recording head of the present invention,
1 and 2 show an embodiment of a flexible cable for supplying a print signal and driving power to the print signal and the reference numeral 1 in the figure.
Recording head units 1 and 1 having the same structure are fixed to a nozzle plate 2 which also serves as a fixed substrate so that the pitch of dots formed between them does not deviate.

These recording heads 1, 1, 1 are shown in FIG.
Drive for ejecting ink droplets generated by a semiconductor device 5 for generating a print signal, which is connected to a host by one flexible cable 3 shown in (b) and is provided in a window 4 formed in the flexible cable 3. Connected to receive signals.

Since this semiconductor device 5 needs to supply a print signal to a large number of piezoelectric vibrators, the integration density is high,
A plurality of general-purpose chips capable of driving a relatively small number of piezoelectric vibrators are housed in one case, and print signal input terminals 60 to 6 are provided on at least the short sides of both ends as shown in FIG.
5, 60 'to 65' are output terminals 66, 66, 66, ..., 66 ', 66', 6 for outputting drive signals to the long sides.
6 '... are provided.

FIG. 2 is a view showing an embodiment of each of the recording head units 1 in the longitudinal sectional structure of the pressure generating chambers 11 and 12, and FIG. 3 is a top elastic plate 1 which will be described later.
3, the pressure generating chambers 11 and 12 and the ink supply port 3 are removed.
1 is a view showing an arrangement of nozzle openings 42 and 43 and nozzle openings 42 and 43. In the drawing, reference numeral 10 is a spacer, and a depth is 150 μm.
The pressure generating chambers 11 and 12 have nozzle openings 42 on a substrate made of a ceramic plate such as zirconia (ZrO 2) having a thickness suitable for forming the pressure generating chambers 11 and 12.
The alignment lines A and 43 are arranged so that the longitudinal axis thereof is inclined at an angle θ.

Reference numeral 13 is an elastic plate, which exerts a sufficient joining force when integrally fired with the spacer 10, and
The piezoelectric vibrators 16 and 17 described later are made of a material that is elastically deformed by flexural vibration, for example, a thin plate of zirconia having a thickness of 7 μm.

Lower electrodes 14 and 15 are formed in regions of the elastic plate 13 facing the pressure generating chambers 11 and 12, and a green sheet of a piezoelectric material is baked on the surface of the lower electrodes 14 and 15 so as to face the pressure generating chambers 11 and 12. The piezoelectric vibrators 16 and 17 are connected to each other to be assembled, and the upper electrode 1 is attached to the surface of the piezoelectric vibrators 16 and 17.
8 and 19 are formed.

In the central dead space where the two rows of piezoelectric vibrators 16 and 17 are formed, as shown in FIG. 4, conductive patterns 20, 21 and 22 extending in the arrangement direction of the pressure generating chambers 11 and 12 are formed. , 23 and 24 are formed with at least one line, and in this embodiment, five lines are formed. When the recording head units 1, 1, 1 are arranged so as to function as recording heads, these conductive patterns 20 to 24 are preferably one ends 20a to 24a on the facing surfaces of the adjacent recording head units 1, 1, 1. Are formed so as to be located at the same positions as the other ends 20b to 24b.

These conductive patterns 20 to 24 are relatively wide and can be formed as thick films by the same method as that for the lower electrodes 14 and 15, that is, thick film printing of a conductive paint or sputtering of a conductive material. In particular, it is most suitable for forming a conductive pattern for supplying drive power or a ground pattern for which the resistance value needs to be as small as possible.

In FIG. 4, reference numerals 25 and 26 in the drawing denote connection terminal portions to be connected to the connection terminals 54b and 55b of the flexible cable 3, and 27 and 28 denote the piezoelectric vibrator 1.
Conductive patterns for connecting the segment electrodes 6 and 17, for example, the upper electrodes 18 and 19 and the connection terminal portions 25 and 26 are shown.

Reference numeral 30 in the drawing is a cover plate integrally attached to the other surface of the spacer 10, and in this embodiment, the thickness is 100 μm.
A thin plate of zirconia, which will be described later,
Ink supply ports 31 and 32 which connect the pressure generating chambers 11 and 12 to each other and are capable of ejecting ink droplets and have a fluid resistance enough to supply ink to the pressure generating chambers 11 and 12.
And nozzle communication holes 33 and 34 that connect the nozzle openings 42 and 43 to the pressure generating chambers 11 and 12, and an ink introduction port that supplies ink to the reservoirs 38 and 39 from the outside at a position not covered by the recording head unit 1. 35 and 36 are formed.

A reservoir forming substrate 37 communicates with the ink supply ports 31 and 32 of the ink supply port forming substrate 30 and supplies the ink supplied from the ink introducing ports 35 and 36 to the pressure generating chambers 11 and 12. 38, 39, nozzle communication holes 40, 41 for connecting the nozzle openings 42, 43 and the pressure generating chambers 11, 12 are formed.

Among these members 10, 13, 30, 37, members 10, 13, 30 made of ceramic material
Is a member 3 that is integrally formed by firing or is made of metal or the like.
7 is fixed by a joining method suitable for joining with ceramics and is assembled in the above-described recording head unit 1.

Reference numeral 2 is the above-mentioned nozzle plate, and as shown in FIG. 5, each nozzle communication hole 33, 40, and 34, 41.
Through the pressure generating chambers 11 and 12 of the recording head unit 1.
The nozzle openings 43, 44 communicating with each other are all connected to the adjacent recording head units 1, 1, 1 in the sub-scanning direction,
That is, in order to maintain a constant pitch P in the direction in which the nozzle openings are arranged, the distance ΔL is used in the main scanning direction of the recording head,
That is, they are arranged so as to be displaced in the moving direction of the carriage.

The flexible cable 5 for supplying a print signal to the recording head thus constructed has a plurality of recording head units 1, 1, 1 constituting the recording head as shown in FIG. The length that can be covered and the connection terminals 25 of the recording head units 1, 1, 1 at both ends in the width direction,
A heat-resistant electrically insulating film 51 of polyimide or the like, which is shaped to have a width such that it can contact 26, and is shaped so that the connection lines of the connection terminals 25, 26 of the recording head units 1, 1, 1 are outer ends, A copper foil is attached and a conductive pattern 52 for connecting the copper foil to a host such as a print signal supply line or a power supply line, and the other input terminal 60 ′ of the semiconductor device 5 are connected.
The pattern 53 corresponding to the connection portion with 65 ′, the output terminals 66, 66, 66, ..., 66 ′, 6 of the semiconductor device 5.
6 ', 66', ... (FIG. 7 (a)), the print signal supply patterns 54, 55 are patterned by etching, and the input terminal 6 of the semiconductor device 5 is provided in the vicinity of the window 4.
The exposed areas 56 and 57 for connecting to the terminals 60 to 65 and 60 'to 65' are formed in the areas corresponding to 0 to 65 and 60 'to 65'.

Then, as shown in FIG. 6, the semiconductor device 5
The pattern 52, 53 of the print signal supply line and the power supply line of the window 4 for mounting
A part of the heat-resistant electrically insulating film 51 of 53 is peeled off to form tabs 52a and 53a, and the tips thereof are soldered to the conductive patterns 20 to 24 of the recording head units 1, 1, 1.

Further, in the vicinity of the long side of the window 4, the window side of the drive signal supply patterns 54, 55 is exposed in the same manner as described above to form the tab 54a, and the output terminals 66, 6 of the semiconductor device are formed.
Soldered to 6 '. Further, the input terminals 60 to 65 and 60 ′ to 65 ′ on both sides of the semiconductor device 5 penetrate the exposed regions 56 and 57 and are connected to a host such as a print signal supply line or a power supply line, and a pattern 52 and a pattern 53.
Is soldered to.

On the other hand, at the other ends of the drive signal supply patterns 54 and 55 of the flexible cable 3, the connection portions 54b and 55b are formed by peeling the film 51 to expose the conductive patterns.
Are soldered to the connection terminals 25 and 26 of each recording unit 1. Reference numeral 67 in the figure denotes a conductive connecting member such as solder that connects the boundaries of the conductive patterns 20 to 24 of the recording head unit 1.

In this embodiment, when the flexible cable 3 is connected and the print signal and the drive power from the host are supplied, the first input terminals 60 to 65 of the semiconductor device 5 receive the print signal and the drive power from the patterns 52 and 53. To be supplied. The print signal and the driving power are input from the tab 52a through the conductive patterns 20 to 24 of the recording head units 1, 1, 1 to the other input terminal 60 'to 65' of the semiconductor device 5 from the tab 53a at the other end. .

In this way, the plurality of input terminals 60-65, 6
By receiving the print signal and the drive power from 0 ′ to 65 ′, the plurality of chips housed in the semiconductor device 5 generate the drive signal of each recording head unit 1, 1, 1 based on the print signal. This drive signal is output from the output terminals 66 and 66 ′ of the semiconductor device 5 to the connection terminals 25 and 26 of each recording unit 1 via the drive signal supply patterns 54 and 55 of the flexible cable 3, and the recording head unit 1 The pressure generating chambers 11 and 12 are supplied to the piezoelectric vibrators 16 and 17 of No. 1 and No. 1 to expand and contract the pressure generating chambers 11 and 12 in response to the print signal to eject ink droplets from the nozzle openings 142 and 43.

As described above, the conductive patterns 20 to 24 formed in the dead spaces of the recording heads 1, 1, 1 are wide.
Via the plurality of input terminals 60 to 65, 6 of the semiconductor device 5.
Since the print signal and the drive power are supplied to 0'-65 ', the attenuation can be reduced as compared with the case where the semiconductor device itself is provided with a signal line or a power supply line and the print signal or the drive power is supplied to a plurality of chips. Can be made smaller.

Incidentally, in the above-mentioned embodiment, the two ends
Although the print signal and the driving power are supplied from a location, a connection terminal is also provided in the central portion of the semiconductor device and connected to the conductive patterns 20 to 24 by a wire or the like so that at least a ground connection is made at a plurality of locations. If set to, a reliable noise countermeasure can be taken.

In the above embodiment, the recording head using a plurality of units for expanding and contracting the pressure generating chamber by the flexural vibration of the piezoelectric vibrator has been described as an example. It is obvious that the present invention can be applied to a bubble jet type recording head in which another recording head can be arranged adjacent to the two sides.

Further, in the above-mentioned embodiment, the case where the recording head is constructed by using three head units has been described as an example, but when a larger number of head units are used, it is shown in FIG. As described above, the flexible cable 3 requires two or more semiconductor devices 71 and 72. Even in such a case, the conductive pattern 20 to 24 of the head unit 1 is used as a print signal between the plurality of semiconductor devices 71 and 72. The same effect can be obtained even when applied as a conductive path for transmission of power and supply of driving power.

Further, although the nozzle plate is used as the fixed substrate in the above-described embodiment, the nozzle plate is provided in the head unit itself to constitute a unit capable of ejecting ink droplets independently, and a plurality of these are formed. It is obvious that the same effect can be obtained even if the circuit board is mounted on a fixed board.

[0033]

As described above, according to the present invention, the attenuation can be reduced as compared with the case where the semiconductor device itself is provided with the signal line and the power supply line to supply the print signal and the driving power to the plurality of chips. The printhead and the drive power can be prevented from being attenuated and the printhead can be reliably driven even with a long printhead.

[Brief description of drawings]

1A and 1B are views showing an embodiment of an inkjet recording head of the present invention and a flexible cable for supplying a print signal to the inkjet recording head, respectively.

FIG. 2 is a diagram showing an embodiment of a recording head unit constituting the ink jet recording head of the present invention with a sectional structure in the vicinity of a pressure generating chamber.

FIG. 3 is a diagram showing an arrangement of pressure generating chambers of a recording head unit that constitutes the same recording head.

FIG. 4 is a diagram showing an embodiment of an elastic plate of a recording head unit that constitutes the same inkjet recording head.

FIG. 5 is a diagram showing an embodiment of the nozzle plate of the ink jet recording head of the above.

FIG. 6 is an enlarged view showing a connection structure in the vicinity of a semiconductor device.

7A and 7B are a front view and a cross-sectional view, respectively, showing a terminal structure of a semiconductor device.

FIG. 8 is a diagram showing another embodiment of a flexible cable to which the present invention is applicable.

[Explanation of symbols]

1 Recording head unit 2 nozzle plate 3 flexible cable 4 windows 5 Semiconductor device 10 Spacer 11, 12 Pressure generation chamber 13 Elastic plate 16, 17 Piezoelectric vibrator 20-24 Conductive pattern formed on elastic plate 42,43 Nozzle opening

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-198876 (JP, A) JP-A-10-6496 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B41J 2/045 B41J 2/055

Claims (5)

(57) [Claims] And 1. A pressure generating chambers communicating with nozzle openings, a pressure generation means for pressurizing a pressure generation chamber, and the recording head unit example Bei connection terminal for supplying a print signal to the pressure generating means, an external drive a print signal generating semiconductor device that generates a print signal which drives the pressure generating means based on a print signal from the means supplies a print signal from the external drive unit to the semiconductor device, connected to the connection terminals In the ink jet recording head comprising a signal supply member for supplying a print signal generated by the semiconductor device to the pressure generating means, a conductive member extending in the arrangement direction of the pressure generating chambers at the center of the surface of the recording head unit. pattern is formed, the signal
An ink jet recording head for transmitting a print signal or a driving power supplied from a signal supply member to another area separated from the input side through the conductive pattern. 2. The signal supply member is a flexible cable.
The ink jet recording head according to claim 1, wherein the ink jet recording head is configured by a package, and the semiconductor device is mounted on the flexible cable. 3. The signal supply member is a flexible cable.
A window is formed in a region of the flexible cable where the semiconductor device is mounted, and a tab of a metal foil forming a conductive pattern is exposed on the window side, and is formed on the tab and the recording head unit. The ink jet recording head according to claim 2, wherein the conductive pattern is electrically connected to the conductive pattern. 4. The ink jet recording head according to claim 3 , wherein an exposed region connected to an input terminal of the semiconductor device is formed near the window. 5. The semiconductor device has a plurality of input terminal groups, and at least one of the input terminal groups is supplied with a print signal or drive power via the conductive pattern formed in the recording head unit. 1. The inkjet recording head according to 1.