The present invention relates to an ink jet recording head used for such a recording apparatus that forms images by jetting recording liquid, such as ink, in the form of a droplet from its liquid jetting holes. It also relates to a method for manufacturing an ink jet recording head.
An ink jet recording apparatus is a recording apparatus which uses a so-called nonimpact recording method. Thus, it is characterized in that not only does it make virtually no noise when it is recording, but also, it is capable of recording on a variety of recording media at a high speed. Because of these characteristics, an ink jet recording apparatus is widely used as a part of the recording mechanism of a printer, a copying machine, a facsimile machine, wordprocessor, or the like.
The typical ink jetting methods used by a recording head mounted in an ink jet recording apparatus, such as those mentioned above, are as follows. One of them is the method which uses an electro-mechanical transducer, such as a piezoelectric element. Another one is the method which heats ink by irradiating ink with electromagnetic waves, such as laser light, to jet ink droplets. Also known is an ink jetting method which heats ink with the use of an electrothermal transducer, such as a heat generating resistor, to cause the ink to boil in the manner of so-called film boiling so that the ink is jetted by the pressure generated by the boiling of the ink, that is, the growth of a bubble in the ink.
Among the various ink jet recording heads mentioned above, there is the ink jet recording head which uses electrothermal transducers and records images by jetting ink onto a recording medium. More specifically, the ink jet recording head is provided with recording liquid chambers, in which an electrothermal transducer is disposed. In operation, recording signals, which are in the form of an electrical pulse, are sent to the electrothermal transducer. As the electrothermal transducer receives recording signals, it generates heat (thermal energy), causing the ink in the recording liquid chamber to boil (changes in phase); it generates a bubble (bubbles) in the ink in the recording liquid chamber. As the bubble grows, it increases the pressure in the recording liquid chamber. As a result, the ink is jetted out of the microscopic outlet (nozzle), onto recording medium, forming an image on the recording medium. That is, an ink jet recording head which uses electrothermal transducers has: nozzles, one end of which opens outwardly; ink passages through which the nozzles are supplied with ink; and a common liquid (ink) chamber (or chambers), from which ink is delivered to each of the nozzles.
Further, some ink jet recording heads are structured so that their ink containers are separable from their ink jet recording head portions, whereas others are structured so that their ink jet containers are not separable from their ink jet recording head portions.
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The ink jet cartridge which will be described next is a color ink jet cartridge which prints images by jetting yellow, magenta, and cyan inks.
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There are also supporting members 801 formed of a resinous substance. A supporting member 801 formed of a resinous substance is lower in the positional accuracy with which the recording chip can be bonded to the supporting member 801 than a supporting member 801 formed of alumina or the like. However, it is advantageous in that it can be less expensively manufactured than a supporting member 801 formed of alumina or the like.
As the adhesive for bonding the recording chip to the supporting member 801, it is common practice to use one of the adhesives which are curable with ultraviolet rays and heat, because they are easy to handle in the bonding step in the manufacture of an ink jet recording head portion.
In the case of an ink jet recording head portion which is in accordance with the invention disclosed in Japanese Laid-open patent Application 2002-154209, each of the partitioning walls of the supporting member, which keeps the adjacent two common liquid passages from each other, is thicker than the distance between the openings of the adjacent two common liquid passages. This structural arrangement does not require the positional accuracy with which the adhesive is applied to the partitioning walls of the supporting member, to be very high. Therefore, this structural arrangement makes it unnecessary for the recording chip to be positioned relative to the supporting member, with extremely high accuracy.
In recent years, ink jet recording heads have been continuously falling in price. In order to reduce an ink jet recording head in its manufacturing cost, it is required to manufacture an ink jet recording head without raising the accuracy with which a recording chip is positioned relative to the supporting member, and also, with the use of an inexpensive manufacturing apparatuses. However, relaxing the accuracy with which a recording chip is positioned relative to its supporting member is likely to cause the following problems.
That is, when the adhesive for bonding a recording chip to a supporting member was applied to the supporting member, the adhesive failed to land on the center of the adhesive application surface of the partitioning wall, in terms of the widthwise direction of the partitioning wall, and therefore, the body of the applied adhesive slumped into the adjacent common ink passage(s). This resulted in the problem that the ink in a given common ink passage and the ink in the adjacent common ink passage mixed with each other in the ink jet recording head. The results of the analysis of this problem revealed that in order to ensure that the adhesive accurately lands on the center of the adhesive application surface of the partitioning wall, in terms of the widthwise direction of the partitioning wall, in a manner of drawing a fine line on the adhesive application surface of the partitioning wall with the adhesive, the adhesive application needle has to be highly accurately positioned relative to the supporting member. More specifically, the amount of the positional deviation between the needle and supporting member had to be no more than ±50 μm.
Reducing an adhesive application needle in diameter allows the abovementioned positioning accuracy to be relaxed. However, reducing an adhesive application needle in diameter increases the needle in flow resistance. Thus, it reduces the amount by which adhesive can be squeezed out of the adhesive applicator per unit length of time. Therefore, it increases the amount of time necessary to coat each recording head with the adhesive. This increases the length of time necessary to coat each recording head with the adhesive, and also, complicates the manufacturing line, which results in reduction in the productivity of the manufacturing line, and also, results in increase in manufacturing cost.
The primary object of the present invention is to provide an ink jet recording head which does not suffer from the problems which a conventional ink jet recording head, that is, an ink jet recording head in accordance with the above described background technologies, suffers, and also, to provide a method for manufacturing the ink jet recording head which does not suffer from the problem which a conventional ink jet recording head suffers.
Another object of the present invention is to provide an ink jet recording head which is satisfactory and stable in print quality, and yet, is no lower in manufacturing efficiency and no higher in manufacturing cost than a conventional ink jet recording head.
The present invention relates to an ink jet recording head, which has a recording chip and its supporting member, and which is manufactured by coating the chip supporting surface of the supporting member with adhesive. It also relates to a method for manufacturing the ink jet recording head. According to the present invention made to achieve the objects described above, the adhesive application area of the recording chip supporting member of an ink jet recording cartridge is shaped so that it surrounds the common ink passages(s) of the supporting member, and also, so that one of the lengthwise end portions of each of the columnar portions of the adhesive application area is wider than the rest of the columnar portion.
Also according to the present invention, it is possible to provide an ink jet recording head which is satisfactory and stable in print quality, and yet, is no lower in manufacturing efficiency and no higher in manufacturing cost than a conventional ink jet recording head.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
Hereinafter, the present invention will be described with reference to the appended drawings.
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The recording chip H1101 is made up of a substrate formed of silicon, multiple energy generating elements (unshown) for jetting ink, electrical wiring (unshown) formed of aluminum or the like. The multiple energy generating elements and wiring are formed on one of the primary surfaces of the silicon substrate, with the use of a film formation technology. The silicon substrate is 0.62 mm in thickness.
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The electrical wiring board (plate) H1301 has a device hole (unshown), in which the recording chip H1101 fits. Further, the electrical wiring board H1301 has: electrical terminals which correspond to the electrodes (unshown) of the recording chip; and external signal input terminals H1303, through which the recording chip H1101 receives drive control signals from the main assembly of the printer. The external signal input terminals H1303 are in connection to the electrical terminals H1302 through the wiring formed of copper foil.
The supporting member H1501 is formed of a resinous substance by molding. In this embodiment, a resinous composite, which contains glass filler by 35% for rigidity, is used as the material for the supporting member H1501. This supporting member has ink delivery passages H1502, which are in connection to an ink storage portion (unshown). The recording chip supporting surface H1504 of the supporting member H1501 is provided with an adhesive application area H1503. In the case of the ink jet recording cartridge in this embodiment, the ink jet recording head is immovably attached to the ink container formed of a relatively inexpensive resinous substance. However, this embodiment is not intended to limit the present invention in scope. That is, the ink jet recording cartridge may be structured so that the ink container is separable from the ink jet recording head portion. Further, it may be formed of such a substance as aluminum.
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In this embodiment, therefore, the portion (b) of each of the columnar area (b) of the adhesive application area H1503 is widened to 0.6 mm, as shown in
Further, shaping the adhesive application area H1503 as shown in
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The level of viscosity of the adhesive H1201 is optional. That is, it may be selected as fits, as long as the body of the applied adhesive H1201 on the adhesive application area H1503 remains stable in shape. In this embodiment, an adhesive which is 14,000 mPa×s in viscosity, and 1.8 in thixotropic index was used as the adhesive H1201.
The adhesive H1201 is applied to the columnar portions of the adhesive application area H1503 and also, the rest of the adhesive application area H1503, with the adhesive application needle H1202. In a case where the direction in which the adhesive H1201 is applied to each of the columnar portions of the adhesive application area H1503 is parallel to the direction indicated by an arrow mark Y (which is parallel to direction in which ink jetting holes are aligned), the application is started at a point in one of the wide portions of each of the columnar portions of the adhesive application area H1503, and then, is continued in the direction parallel to the direction Y through the narrow portion of the columnar portion, and is ended in the other wide portion of the columnar portion, as shown in
As will be evident from the description of this embodiment given above, the present invention makes it possible to provide a reliable ink jet recording head without drastically improving in accuracy the apparatus for manufacturing an ink jet recording head.
The width of the columnar portions of the adhesive application area H1503 does not need to be limited to the value in this embodiment. That is, it has only to be determined according to the adhesive selection, needle size, manufacturing apparatus accuracy, amount by which the adhesive is applied, etc.
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According to each of the above described preferred embodiments of the present invention, the supporting member H1501 is shaped so that at least one of the lengthwise end portion of each of the columnar portions of the adhesive application area H1503, more specifically, the lengthwise end portion in which the application of the adhesive H1201 to the adhesive application area H1503 in a manner of drawing a fine line on the adhesive application area H1503 with the adhesive H1201 is started, is wider than the other portion (lengthwise center portion) of the columnar portion.
Shaping the supporting member H1501 as described above makes it possible to compensate for the positional deviation of the body of the applied adhesive H1201, which is attributable to the inaccuracy with which the supporting member H1501 and needle H1202 are positioned relative to each other, without drastically improving in accuracy the apparatus for assembling an ink jet recording head. Therefore, it can prevent the problem that after the application of the adhesive H1201 to the adhesive application area H1503, the body of the applied adhesive H1201 slumps into the ink delivery passage(s) of the supporting member H1501. Therefore, it can prevent the problem that the ink in a given ink delivery passage H1502 and the ink in the adjacent ink delivery passage(s) H1502 mix in the ink jet recording head. Thus, it makes it possible to provide an ink jet recording head which does not suffer from the problem that an ink jet recording head prints unsatisfactory images due to the ink mixture which occurs in the ink jet recording head because of the mixture between the ink in a given ink delivery passage of the supporting member and the ink in the adjacent ink delivery passage(s) of the supporting member of the head. Further, shaping the supporting member H1501 as described above makes it possible to satisfactorily apply the adhesive H1201 without reducing the diameter of the needle H1202. Thus, it can prevent the problem that the productivity in the manufacturing of an ink jet recording head is reduced by the reduction in the diameter of the needle H1202.
As will be evident from the description of the preferred embodiments of the present invention given above, the present invention can provide an ink jet recording head which is satisfactory and stable in image quality, and yet, inexpensive because it is simple in structure and low in manufacturing cost.
Further, not only is the present invention satisfactorily applicable to an ordinary printing apparatus, but also, a copying machine, a facsimile machine, a wordprocessor having a printing portion, a multifunction recording apparatus made up of a combination of the preceding apparatuses, etc.
Further, an ink jet recording head in accordance with the present invention can be satisfactory mounted in a printer, a copying machine, a facsimile machine, a word processor having a printer portion, an industrial recording apparatus made up of a complex combination of the preceding apparatuses, etc.
The usage of an ink jet recording apparatus in accordance with the present invention makes it possible to record on such recording medium as paper, thread, fiber, leather, metal, plastic, glass, lumber, ceramic, etc. Incidentally, “recording” mentioned in the description of the preferred embodiments of the present invention given above means placing on recording medium, not only an image, such as a letter and a figure, that has a meaning, but also, a meaningless image such as a meaningless pattern.
While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
This application claims priority from Japanese Patent Application No. 046252/2008 filed Feb. 27, 2008 which is hereby incorporated by reference.
Number | Date | Country | Kind |
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2008-046252 | Feb 2008 | JP | national |
Number | Name | Date | Kind |
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6652702 | Miyazaki et al. | Nov 2003 | B2 |
6799831 | Inamoto et al. | Oct 2004 | B2 |
20070285465 | Shibata et al. | Dec 2007 | A1 |
Number | Date | Country |
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2002-154209 | May 2002 | JP |
Number | Date | Country | |
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20090213169 A1 | Aug 2009 | US |