JPH0890774A - Inkjet head and inkjet recording apparatus using the inkjet head - Google Patents

Abstract

(57) [Summary] [Purpose] During storage and distribution with a protective cap,
The deformation of the orifice plate and the intrusion of the sealing material existing between the orifice plate and one end of the heater plate into the flow path are prevented. [Structure] Inner surface of orifice plate 7 (side surface of liquid path)
Is provided with a protrusion (rib 10) facing the end of the base plate 12 on the orifice plate side.

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 for ejecting ink droplets onto a recording medium for recording and an ink jet recording apparatus using the ink jet head.

[0002]

2. Description of the Related Art Conventionally, as an ejection energy generating element of an ink jet head, an element using an electrothermal converter is well known. As one configuration of this head, there is one in which a top plate having a groove for forming a liquid path or the like provided corresponding to the electrothermal converter is bonded to the substrate on which the electrothermal converter is formed. FIG. 5 shows an example of a structure in which such a head is integrated with an ink tank.

FIG. 5 is an exploded perspective view showing an example of an ink jet head cartridge.

In FIG. 5, the head unit employs an ink jet recording system in which ink is ejected by generating heat energy in response to an electric signal to cause film boiling in the ink, and a heater board described below. 121, a wiring board 123, a top plate 116, a base plate 122, and a pressing spring 127.

The heater board 121 has a plurality of rows of electrothermal converters (heaters for discharge) for generating the above-mentioned thermal energy formed on the Si substrate by a film forming technique, and each electrothermal converter is provided with a row. Electrical wiring such as Al for supplying electricity is formed.

The wiring board 123 is a heater board 121.
Corresponding to the above wiring and connected by, for example, wire bonding, and a pad 124 located at the end of this wiring and receiving an electric signal from the main body device.

The top plate 116 is provided with partition walls for forming an ink flow path and a common liquid chamber corresponding to each of the plurality of ink ejection ports, and receives the ink supplied from the ink tank to receive the common liquid. An ink receiving port 125 for introducing into the chamber and an orifice plate 117 having a plurality of ejection ports are integrally provided. The partition walls and the like of the top plate 116 are integrally molded with the top plate 116, and polysulfone is preferable as the integrally molded material of these, but other molding resins may be used.

The base plate 122 supports the back surface of the wiring substrate 123 on a flat surface and is made of, for example, metal and forms one structural member of the recording head unit.

The presser spring 126 has an M shape, and its M
A portion of the top plate 116 corresponding to the common liquid chamber is pressed at the center of the character, and a portion of the top plate 116 corresponding to the liquid path of the top plate 116 is also pressed by line contact. Presser spring 126
The foot portion of the base plate 122 passes through the hole 128 of the base plate 122 and engages with the back surface side of the base plate 122, so that the heater board 121 and the top plate 116 are connected to each other.
It is sandwiched between the base plate 12 and the heater board 121 and the top plate 116 by the biasing force of the presser spring 126 and the front slant portion 127.
2 can be fixed by pressure.

At this time, in order to prevent crosstalk between the ink flow paths at the time of ink ejection, a top plate having a jaw portion is used (Japanese Patent Laid-Open No. 1-241046) or a tip of a heater board of the top plate. Use a rib (protrusion) on the part to be joined to
Using a sealing material such as urethane resin, acrylic resin, flexible epoxy resin, or rubber adhesive (Japanese Patent Application No. 3-
No. 004709) has been proposed.

The base plate 122 has two positioning protrusions 129 provided on the ink tank, and two positioning holes 140 for engaging with the two positioning and heat-fusion holding protrusions 130, respectively. In addition to the base plate 1
Reference numeral 22 also has a hole that allows the ink supply pipe 131 that allows ink to be supplied from the ink tank to pass therethrough. The wiring board 123 is attached to the base plate 122 by adhering it with an adhesive or the like.

Further, the ink jet cartridge in FIG. 5 has a lid member 133 which is an outer wall of the ink jet cartridge in which a portion for accommodating the recording head unit constructed as described above is formed, and an ink supply passage member 13.
5, the parallel groove 132 is formed in the lid member 133,
A parallel groove 132 is also formed in the ink supply path member 135.

The ink supply path member 135 is provided in the form of a cantilever in which the connection side between the ink supply pipe 131 and the ink conduit 136 which communicates with the ink supply pipe 131 is fixed. Conduit 136
A sealing pin 137 for ensuring a capillarity phenomenon with the ink supply tube 131 is provided in the fixing portion.

The ink tank and the ink supply pipe 131
A packing 138 for sealing is provided at the connecting portion with. A filter 139 is provided at the end of the ink supply pipe 131 on the tank side.

Since the ink supply path member 135 is formed by molding, it is not only formed at a high price with high waste, but also cantilevered in the shape of the ink conduit 136, and the ink conduit 136 in the form of a cantilever also allows the ink conduit 136 to reach the ceiling. The pressure contact state of the plate 116 with respect to the ink receiving port 125 can be stabilized.

In this example, the sealing adhesive is poured from the ink supply path side under this pressure contact state. To fix the ink supply path member 135 to the base plate 122, the back surface side pin (not shown) of the ink supply path member 135 with respect to the hole 141 of the base plate 122 is fixed to the base plate 122.
Through the hole 141 of the base plate 1
This is easily performed by heat-sealing the portion of the back surface 22 that protrudes to the back surface side. The heat-sealed slight protruding area of the back surface portion is accommodated in the recess (not shown) in the side wall surface of the head unit mounting surface of the ink tank, so that the positioning surface of the head unit can be accurately obtained.

FIG. 6 shows the form of storage and distribution of the ink jet head cartridge manufactured as described above.

FIG. 6 is a vertical cross-sectional view of the top plate of the head unit manufactured as described above, the discharge port of the heater board, and the liquid passage around the discharge port.

As shown in FIG. 6, a protective tape 143 is attached to the ejection port surface of the orifice plate 117 so that the ink in the ejection port section 142 does not stick to it even if it is left for a long time, and the protective tape 143 is also attached. The protective tape 143 is attached to the protective cap 14 in order to prevent misalignment and complete contact with the discharge port surface.
It is pressed and fixed at 4. In this case, the protective cap pressing portion is made of a material such as urethane foam that can follow the shape of the discharge port surface.

[0020]

However, since the head unit having the above-described structure is provided with ribs (protrusions) on the portion of the top plate that is joined to the tip of the heater board, the head unit as shown in FIG. A gap X is always generated between the orifice plate provided on the plate and the base plate after assembly. If the ejection port surface of the recording head unit is pressed with a protective cap in such a state and left at high temperature for a long time, the orifice plate may deform or the orifice plate and heater plate side of the orifice plate side. The sealing material existing between the end surface and the end surface may be extruded and enter the flow path, resulting in defective printing.

In particular, in the case of storage and distribution of an ink jet head which can be attached and detached on the carriage, a protective tape and a protective cap are required, and compared with the cap pressing pressure in the ejection port suction recovery operation on the printer, storage is possible. Since the pressing force of the protective cap during distribution and distribution is much stronger, it was a particular problem.

In view of the above-mentioned problems of the prior art, the present invention, therefore, deforms the orifice plate and preserves the flow of the sealing material existing between the orifice plate and one end of the heater plate during storage by a protective cap and distribution. An object of the present invention is to provide an inkjet head capable of preventing the intrusion into the road and an inkjet recording device using the inkjet head.

[0023]

In order to achieve the above object, an ink jet head of the present invention has a first member provided with a plurality of energy generating elements for ejecting ink, and is joined to the first member. And an orifice plate formed with a plurality of ink ejection openings, which abut when the first member is joined.
A groove serving as an ink flow path is formed corresponding to each of the energy generating elements in a portion of the member that is joined to the portion where the plurality of energy generating elements are provided, and one end of the groove and the ejection port of the orifice plate are formed. A second member that communicates with each other; and a third member that supports the first member to which the second member is joined and that has one end facing the orifice plate of the second member, The orifice plate of the second member facing one end of the three members is provided with a protrusion.

Further, a first member provided with a plurality of energy generating elements for ejecting ink, and a plurality of ink ejection ports that are joined to the first member and abut when the first member is joined. And a groove serving as an ink flow path corresponding to each of the energy generating elements in a portion of the first member that is joined to the portion where the plurality of energy generating elements are provided. A second member that is formed by connecting one end of the groove to the discharge port of the orifice plate and the first member to which the second member is joined, and supports the second member.
The inkjet head may include a third member whose one end faces the orifice plate of the member, and the protrusion may be provided at one end of the third member facing the orifice plate of the second member.

In the ink jet head, the energy generating element is an electrothermal converter,
Bubbles are generated in the ink by the electrothermal converter, and the ink is ejected as the bubbles are generated.

Further, an ink jet recording apparatus in which an ink jet head cartridge in which the ink jet head is integrated with an ink tank is detachably provided on a reciprocating carriage is also included in the present invention.

[0027]

According to the present invention constructed as described above, when the ink jet head is stored and distributed, a protective cap is put on the orifice plate (discharging port surface) of the top plate constituting the ink jet head and the orifice plate is pressed. By providing a protrusion at a portion of the orifice plate that faces one end of the third member (base board) or at one end of the third member (base board) that faces the orifice plate, the protrusion of the orifice plate becomes the third protrusion.
The orifice plate is prevented from being deformed by hitting the member.

Further, since the deformation of the orifice plate is restricted by the protrusion, the sealing material interposed between the orifice plate and the one end of the first member (heater board) may be extruded and leak into the flow path. It is possible to provide an inkjet recording device which is prevented and has high reliability.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 1 is a perspective view of a top plate constituting a first embodiment of an ink jet head of the present invention. FIG. 2 shows that the top plate, which is the second member shown in FIG. 1, and the heater board, which is the first member having the electrothermal converter that is the discharge energy element for discharging ink, are joined together, and the presser spring is further attached. , The top plate is crimped, and the top plate after being supported by the base plate which is the third member,
FIG. 3 is a vertical cross-sectional view of a discharge port of a heater board and a liquid passage around the discharge port.

In FIG. 1, the top plate 6 of the ink jet head of the present embodiment has a first surface to which the electrothermal converter forming surfaces of the heater boards, which are orthogonal to each other, are joined, and the electrothermal converter array direction of the heater board. Has a second surface (inner surface of the orifice plate 7) to which one end surface parallel to is joined.

On the first surface, ink channel grooves 3 corresponding to each of the plurality of electrothermal converters on the heater board.
And a common liquid chamber forming recess 5 communicating with the entire one end side of each ink flow channel groove 3 is formed. An ink ejection port 2 communicating with the outside of the top plate 6 is provided on each of the other end side surfaces of each ink channel groove 3.

The first surface is the second surface,
A step portion 8 (hereinafter referred to as an “jaw portion”) is formed between the inner side surface of the orifice plate 7 (that is, the surface on the liquid path side) and the other end side of the ink flow path groove 3, and the jaw is formed. The portion is provided with a protrusion 9 for preventing crosstalk between ink flow paths formed at the time of joining with a heater board.

In this embodiment, the top plate 6 is made of a resin such as polysulfone, polyether sulfone, polyphenylene oxide, polypropylene, etc., which has excellent ink resistance, and is integrally molded together with the orifice plate 7 in the mold. There is.

Further, as shown in FIGS. 1 and 2, a protrusion (hereinafter referred to as "rib 10") is formed on the inner surface of the orifice plate 7 (the side surface of the liquid path), as opposed to the end portion of the base plate 12 on the orifice plate side. ) Is provided, the rib 10
Also serves as a positioning member when the top plate 6 is butted against the heater board 11 to be joined.

The heater board 11 is the base plate 1
A heater board of about 100 μm is provided between the base plate 1 and the orifice plate 7 so that the sealing material can easily go around between the base plate 12 and the orifice plate 7 at the time of bonding (bonding) with the base plate 1.
It is projected and joined from 2.

In this embodiment, the rib 10 is arranged so as to be orthogonal to the groove length direction of the ink flow path groove 3, and the sealing material can easily enter right after the protrusion 9, so that when the ink is ejected. It has a structure that prevents crosstalk.

The height Y of the rib 10 formed on the orifice plate 7 is 100 μm (the orifice plate 7 and the base plate 1 facing the orifice plate 1).
2 is smaller than the gap between the end face and the end face). In order to protect the ejection surface of the recording head during physical distribution and storage of the completed recording head, a protective tape is applied and a protective cap is attached on top of it. In this way, the orifice plate surface was pressed with the protective cap. At this time, the rib 10 of the orifice plate 7 is replaced by the base plate 1
This is to prevent the orifice plate 7 from bending when it hits 2. However, this rib 10 is the heater board 1.
In consideration of the bonding accuracy between 1 and the base plate 12, the dimensional accuracy of each component, etc., when the recording head is assembled, the rib 10 abuts on the base plate 12 and the orifice plate 7 is not bent. I have to

In this embodiment, the height of the rib 10 is 4
0 μm and 80 μm, with and without protrusions 9,
A total of 6 prototypes were made, and the distribution form was equipped with a protective tape and a protective cap. Evaluation under high temperature conditions for acceleration experiments (60
C., stored for 2 months). The results are shown in Table 1.

[0040]

[Table 1] As shown in the above evaluation results, by providing the rib 10 on the inner surface of the orifice plate (side surface of the liquid passage), the orifice plate may be deformed or the orifice may be deformed by the pressing pressure of the cap even during long-term storage in a physical distribution form (with a protective cap). The occurrence of defects such as the encapsulant between the plate and the heater board getting into the nozzle disappeared.

Further, by providing the protrusions 9, the number of defects is further reduced, and the ink jet cartridge has high reliability.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention in which a top plate and a heater board provided with an electrothermal converter for ejecting ink are joined together, and a pressing spring is further provided. FIG. 4 is a vertical cross-sectional view of the top plate, the discharge port of the heater board, and the liquid path around the discharge port after the top plate is attached and the top plate is pressure-bonded and supported by the base board.

In this embodiment, as shown in FIG.
The rib 13 is provided on the end face of the No. 2 orifice plate side. As a result, it is possible to obtain the same effect as that in which the rib 10 is provided on the inner surface (liquid path side surface) of the orifice plate shown in the above-described embodiment.

(Third Embodiment) FIG. 4 is an external perspective view showing an example of an ink jet recording apparatus in which the ink jet head obtained by the present invention is mounted as a head cartridge as shown in FIG.

As shown in FIG. 4, the ink jet recording apparatus of the present embodiment has an ink jet head having a nozzle group for ejecting ink in opposition to the recording surface of the recording paper fed onto the platen 24. A cartridge 20 is provided. The head cartridge 20 is formed by integrating the recording head and the ink tank shown in the above-described embodiment as shown in FIG. 5, and is held by the carriage 16. The carriage 16 is connected to a part of a drive belt 18 that transmits the driving force of the drive motor 17, and is slidable with two guide shafts 19A and 19B arranged in parallel with each other. As a result, the head cartridge 20
Enables reciprocating movement over the entire width of the recording paper.

Further, a head recovery device 26 is arranged at one end of the movement path of the head cartridge 20, for example, at a position facing the home position. The head recovery device 26 operates by the driving force of the motor 22 via the transmission mechanism 23 and caps the head cartridge 20.

The cap portion 26 of the head recovery device 26
In association with the capping of the head cartridge 20 by A, ink is sucked by an appropriate suction means provided in the head recovery device 26 or ink is pressure-fed by an appropriate pressure means provided in an ink supply path to the head cartridge 20. The ejection recovery process such as removing the thickened ink in the nozzle by forcibly ejecting the ink from the ejection port is performed. Further, the head cartridge 20 is protected by capping at the end of recording or the like.

On the side surface of the head recovery device 26, a blade 30 made of silicon rubber as a wiping member.
Is provided. The blade 30 is a blade holding member 3
The head recovery device 2 is held at 0A in a cantilever form.
Similar to 6, the motor 22 and the transmission mechanism 23 operate to enable engagement with the ejection surface of the head cartridge 20. As a result, the blade 30 is used at an appropriate timing in the recording operation of the head cartridge 20 or after the ejection recovery process using the head recovery device 26. After the ejection recovery process, the blade 30 is projected into the movement path of the head cartridge 20 to cause dew condensation on the ejection surface of the head cartridge 20 as the head cartridge 20 moves.
It wipes off wet or dust.

The present invention brings excellent effects particularly in an ink jet type head and a recording apparatus for forming an image by ejecting flying droplets by utilizing thermal energy among the ink jet type.

With regard to its typical structure and principle, see, for example, US Pat. Nos. 4,723,129 and 4740.
What is done using the basic principles disclosed in 796 is preferred. This method can be applied to both the so-called on-demand type and continuous type, but especially in the case of the on-demand type, liquid (ink)
By applying at least one drive signal to the electrothermal converter arranged corresponding to the sheet or liquid path in which is stored, which corresponds to the recorded information and causes a rapid temperature rise exceeding nucleate boiling. , It is effective because it generates heat energy in the electrothermal converter and causes film boiling on the heat-acting surface of the recording head, resulting in the formation of bubbles in the liquid (ink) corresponding to this drive signal on a one-to-one basis. Is. The liquid (ink) is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one droplet. It is more preferable to make the driving signal into a pulse shape because bubbles can be grown and contracted immediately and appropriately, and thus a liquid (ink) with excellent responsiveness can be ejected.

As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. If the conditions described in US Pat. No. 4,313,124 of the invention relating to the rate of temperature rise of the heat acting surface are adopted, more excellent recording can be performed.

As the constitution of the recording head, in addition to the combination constitution of the ejection port, the liquid passage, and the electrothermal converter (the linear liquid passage or the right-angled liquid passage) as disclosed in the above-mentioned respective specifications. The present invention also includes configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which a heat acting portion is arranged in a bending region.

Further, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but the recording head may be integrally formed or a plurality of combinations may be used. The present invention is also extremely effective for a device provided with at least one of full colors by color mixing.

In the embodiment of the present invention described above,
Although the ink is described as a liquid, it is an ink that solidifies at room temperature or lower and softens at room temperature, or is a liquid, or the ink itself is 30 ° C. or higher and 70 ° C. or lower in the above-mentioned inkjet method. Since the temperature is generally adjusted within the range to control the temperature of the ink so that the viscosity of the ink is within the stable ejection range, it is sufficient that the ink is in a liquid state when the use recording signal is applied.

In addition, the temperature rise due to the thermal energy is positively prevented by using it as the energy for changing the state of the ink from the solid state to the liquid state, or the ink is solidified in a standing state for the purpose of preventing evaporation of the ink. In some cases, such as ink that is liquefied by applying heat energy according to a recording signal and ejected as a liquid ink, or one that has already started to solidify when it reaches a recording medium. The use of an ink having a property of being liquefied only by heat energy is also applicable to the present invention. In such a case, the ink is disclosed in JP-A-54-5684.
No. 7 or JP-A-60-71260, a mode in which the porous sheet is opposed to the electrothermal converter in the state of being held as a liquid or solid in the recess or through hole of the porous sheet. Also good. In the present invention, the most effective one for each of the above-mentioned inks is to execute the above-mentioned film boiling method.

In addition, as a form of the recording apparatus according to the present invention, in addition to one provided integrally or separately as an image output terminal of information processing equipment such as a word processor or a computer, a copying apparatus combined with a reader, and It may take the form of a facsimile machine having a transmission / reception function.

[0057]

As described above, according to the present invention, the protrusion (rib) is provided on the orifice plate facing one end of the third member (base board), or the third member (base board) facing the orifice plate is provided. Providing a protrusion (rib) at one end prevents deformation of the orifice plate and prevents the orifice plate from deforming even when a force for pushing the orifice plate for a long period of time is generated, such as during distribution storage with a protective cap. It is possible to eliminate a defect in which the sealing material interposed between one end of the member (heater board) is extruded and leaks into the ink flow path. As a result, the head manufacturing yield is also improved,
It becomes possible to supply an inexpensive and highly reliable inkjet head.

Further, by using such an ink jet head in a recording apparatus, the apparatus performance can be further improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a top plate that constitutes a first embodiment of an inkjet head of the present invention.

FIG. 2 is a diagram showing a structure in which the top plate shown in FIG. 1 and a heater board having an electrothermal converter for ejecting ink are joined, and a pressing spring is further attached to press the top plate to support it by a base board. FIG. 6 is a vertical cross-sectional view of the top plate, the discharge port of the heater board, and the liquid path around the discharge port after the heating.

FIG. 3 is a view showing a second embodiment of the present invention, in which a top plate and a heater board having an electrothermal converter for ejecting ink are joined, and a pressing spring is further attached to press the top plate. FIG. 3 is a vertical cross-sectional view of a top plate, a discharge port of a heater board, and a liquid path around the discharge port after being supported by a base plate.

FIG. 4 is an external perspective view showing an example of an inkjet recording apparatus in which the inkjet head obtained by the present invention is mounted as a head cartridge.

FIG. 5 is an exploded perspective view showing an example of an inkjet head cartridge.

FIG. 6 is a vertical cross-sectional view of a top plate of a conventional inkjet head, a discharge port of a heater board, and a liquid path around the discharge port.

[Explanation of symbols]

 2 Ink ejection port 3 Ink channel groove 5 Common liquid chamber forming recess 6 Top plate 7 Orifice plate 8 Stepped portion 9 Protrusion 10, 13 Rib 11 Heater board 12 Base plate

Claims (4)

[Claims] 1. A first member provided with a plurality of energy generating elements for ejecting ink, and a plurality of ink ejection ports joined to the first member and abutting when the first member is joined. And a groove serving as an ink flow path corresponding to each of the energy generating elements in a portion of the first member that is joined to the portion where the plurality of energy generating elements are provided. A second member, which is formed by connecting one end of the groove and the discharge port of the orifice plate to each other, and the first member to which the second member is joined, and the orifice of the second member. An ink jet head comprising: a plate and a third member whose one end faces each other, and a projection provided on an orifice plate of the second member which faces one end of the third member. 2. A first member provided with a plurality of energy generating elements for ejecting ink, and a plurality of ink ejection ports that are joined to the first member and abut when the first member is joined. And a groove serving as an ink flow path corresponding to each of the energy generating elements in a portion of the first member that is joined to the portion where the plurality of energy generating elements are provided. A second member, which is formed by connecting one end of the groove and the discharge port of the orifice plate to each other, and the first member to which the second member is joined, and the orifice of the second member. A third member having one end opposed to the plate, and the third member opposed to the orifice plate of the second member.
An inkjet head configured by providing a protrusion on one end of a member. 3. The energy generating element is an electrothermal converter, which generates bubbles in the ink by the electrothermal converter and ejects the ink as the bubbles are generated. The inkjet head according to claim 1 or claim 2. 4. The ink jet head according to claim 1, wherein an ink jet head cartridge in which the ink jet head is integrated with an ink tank is removably provided on a reciprocating carriage. Inkjet recording device.