JP2010046853A - Inkjet recording head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately hold an ink cartridge relative to a carriage with a comparatively simple means, and to achieve high-definition recording free from image deterioration to be caused by deviation of a recording head due to tilt of an ink ejection port array. <P>SOLUTION: A Y-direction butting part 31 used for positioning a carriage at the time of mounting, is provided on a first plate 22 that is a support substrate for supporting recording element substrates 24a and 24b. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording head that is held by a recording apparatus main body and performs recording by discharging ink.

  2. Description of the Related Art With the spread of information processing equipment such as copying machines, word processors, computers, and communication equipment, as one of output devices for image recording (printing) of these equipment, an ink jet recording apparatus that performs recording by an ink jet method There is. The ink jet recording apparatus has an advantage that an ink jet recording head as a recording means can be easily made compact, and a high-definition image can be recorded at high speed. In addition, it can be printed on plain paper without requiring special processing, so the running cost is low, and because it is a non-impact method, noise is low, and ink of multiple colors (color, density) is used. By doing so, there is an advantage that it is easy to record a color image.

  As a typical ink discharge method in this ink jet recording apparatus, there is a method using an electrothermal conversion element. In this method, bubbles are generated by the heat generated by the electrothermal transducer, and recording is performed on a recording medium by discharging minute droplets from minute discharge ports using the pressure generated when bubbles are generated. is there. In general, it is composed of an ink jet recording head for forming droplets and a supply system for supplying ink to the head.

  An ink jet recording head using an electrothermal conversion element has an electrothermal conversion element provided in a recording liquid chamber. By applying an electric pulse as a recording signal to this, thermal energy is given to the recording liquid, and the bubble pressure at the time of phase change of the recording liquid, that is, when the recording liquid is foamed (when boiling) is used for discharging the recording droplets. is doing.

  As a configuration example of a conventional ink jet recording head, for example, there is a method disclosed in Patent Document 1.

  Configuration examples of these conventional ink jet recording heads are shown in FIGS. 7 shows an ink jet recording head (referred to as a recording head cartridge) having a recording head main body and an ink holding and supplying system. FIG. 7A is a perspective view of the whole, and FIG. The perspective view of the state which removed the tank is shown. FIG. 6 is an exploded perspective view of the recording head portion of the recording head cartridge. FIG. 8 shows a lower plan view of the recording head portion of the recording head cartridge.

  The recording head cartridge includes an ink tank 61 that stores ink, and a recording head main body 60 on which a recording element substrate that discharges ink supplied from the ink tank 61 from nozzles according to recording information is mounted. ing. It adopts a so-called cartridge system that is detachably mounted on the carriage of the recording apparatus main body.

  This recording head cartridge is provided with, for example, black, cyan, magenta, and yellow independent ink tanks as the ink tank 61. As shown in FIG. 7B, these ink tanks are mounted so as to be independently detachable from the recording head main body 60.

  As shown in FIG. 6, the recording head main body portion includes an ink supply unit 40 that supplies ink from the ink tank 61 to the recording head main body portion 60, and a recording element unit that includes a plurality of recording element substrates for discharging ink. 50.

  The ink supply unit 40 includes an ink supply member, an ink supply filter, a seal rubber, and a flow path member. A seal rubber for preventing the ink from evaporating from the engagement portion and a filter for preventing the entry of dust from the outside are attached to the engagement portion of the ink supply member with the ink supply port of the ink tank 61. A flow path member that forms an ink supply path connected to the ink flow path is attached to the recording element unit side of the ink supply member.

  The recording element unit 50 has a first plate in which an ink supply port communicating with the ink supply path of the flow path member is formed, and a recording element substrate is bonded and fixed on one surface thereof. Yes. On the recording element substrate 54, a plurality of recording elements for ejecting ink and electric wiring made of Al or the like for supplying electric power to each recording element are formed on one side of the Si substrate by a film forming technique. Further, a plurality of ink flow paths and a plurality of ejection openings corresponding to the recording elements are formed on one side by a photolithography technique. An ink supply port for supplying ink to the ink flow path is opened on the back surface, and the recording element substrate is fixed so that the ink supply port communicates with the ink supply port of the first plate 54. ing. Further, the electric wiring tape 51 is fixed to the lower surface of the first plate 54 so as to be electrically connected to the recording element substrate. The electrical wiring tape 51 applies an electrical signal for ejecting ink onto the recording element substrate, and includes electrical wiring corresponding to the recording element substrate. An electrical contact substrate 53 having an external signal input terminal for receiving an electrical signal from the main body is connected to the end of the electrical distribution tape 51. The electrical contact substrate 53 is positioned and fixed on the back side of the ink supply member. The recording element unit is composed of the recording element substrate, the first plate, the electrical wiring tape, and the electrical contact substrate.

  As shown in FIG. 8, the ink supply unit 40 has a structure for mounting the recording head cartridge on the carriage of the ink jet recording apparatus main body. An abutting portion 71 in the Y direction (recording medium transport direction) is formed on the lower surface of the ink supply member as an abutting reference for positioning the recording head cartridge at a predetermined mounting position by contacting the corresponding portion of the carriage. ing. The recording element unit 50 and the ink supply unit 40 have two Y-direction reference surfaces provided on the end face of the first plate of the recording element unit, and Y-direction abutting portions to the carriage provided on the ink supply member. Is positioned and fixed in the Y direction.

The ink supply unit 40 and the recording element unit 50 are configured to communicate with each other between the ink supply paths, and have a hole corresponding to the ink supply path to be connected between the two portions. By sandwiching the joint seal member 41, which is an elastic member, the screw-fixing boss portion 42 of the ink supply unit 40 and the screw-fixing fixing portion 55 of the recording element unit 50 are brought into pressure contact with each other by using the screws 52. The recording element unit 50 is connected, sealed, and coupled so as to be fixed.
JP 2002-209094 A

  In recent years, with the widespread use of ink jet recording systems, there has been a demand for higher definition and higher speed recording operations. Therefore, an ink jet recording head in which a large number of ejection openings are arranged at high density is used. In an ink jet recording apparatus capable of color recording, an ink jet recording head provided with a plurality of ejection opening arrays is used.

  The ink droplets ejected from the ink jet recording head and adhered to the recording medium spread on the recording medium to form dots, and an image is recorded as an aggregate of the dots. The area of one dot greatly depends on the size of the ink droplet, that is, the ink discharge amount. In order to achieve high-definition and high-quality recording comparable to silver salt photographs using the inkjet method, the ink ejected from the inkjet recording head tends to be as fine as possible.

  Incidentally, an ink jet recording head such as the recording head cartridge described in the background art is positioned with respect to a guide shaft of a recording apparatus via a carriage, and main scanning (movement) is performed. An image is generated and printed on the assumption that each ejection port array is accurately perpendicular to the main scan. However, in practice, the inkjet recording head and the carriage may have manufacturing variations, and thus the ejection port array may not be completely perpendicular to the guide shaft.

  Due to this assumption and actual deviation (inclination), the original dot arrangement cannot be performed, and as a result, there is a possibility of causing image degradation such as band unevenness between passes. In particular, as described above, when the ink discharge amount is made finer, the area of one dot becomes smaller, and even if the inclination is the same as the conventional one, the change of the area factor becomes larger and the image deterioration tends to be more conspicuous. is there.

  For this reason, even in the ink jet recording head, it is necessary to hold the ink discharge port array with higher accuracy than the positioning portion with respect to the carriage. For this purpose, it is required that the ink jet recording head be manufactured with high accuracy so that the ejection port array is as perpendicular as possible to the carriage.

  On the other hand, efforts have been made to further expand the color reproduction range in order to achieve high-definition and high-quality recording comparable to silver salt photography using the inkjet method. In recent years, high-quality printers are not limited to conventional black, cyan, magenta, and yellow, and tend to include a large number of ink types such as monochrome inks such as photo black and gray, or special color inks such as green and red. For this reason, in a so-called on-carriage type printer in which a recording head main body and ink tanks are stacked on a carriage, the recording head main body tends to be large because many ink tanks are connected to the recording head main body.

  The strength of the ink supply unit of the recording head main body made of a resin member is reduced by increasing the size. Therefore, in the conventional positioning of the ink supply unit and the carriage, the Y-direction abutting portion provided on the ink supply member at the time of mounting can be modified, and the coupling accuracy between the ink supply unit and the recording element unit can be maintained by the deformation at the time of coupling. Therefore, it is more difficult than ever to ensure tilt accuracy.

  In other words, while there is a demand for improvement in tilt accuracy as the dots become finer, the strength tends to decrease due to the increase in the size of the head as the number of colors increases, making it difficult to ensure accuracy with conventional methods.

  In view of the above problems, the present invention can hold the ink discharge port array with high accuracy perpendicular to the main scanning direction of the recording apparatus main body with relatively simple means, and does not cause image degradation due to the inclination of the discharge port array. The purpose is to enable high-definition recording.

  The present invention is an ink jet recording head of an ink jet recording apparatus provided with a carriage that moves in a second direction that intersects a first direction that is a transport direction of a recording medium, and a liquid droplet is applied to the recording medium. The inkjet recording head includes a recording element substrate that discharges the recording element and a support substrate that supports the recording element substrate.

  In order to achieve the above object, an ink jet recording head according to an aspect of the present invention includes a first direction abutting portion used for positioning in the first direction when the ink jet recording head is attached to the carriage. The first direction abutting portion is provided on the support substrate, and a concave step is provided on the end surface of the first direction abutting portion on the front side of the mounting locus to the carriage.

  According to the present invention, the ink discharge port array can be accurately held perpendicularly to the main scanning direction of the recording apparatus main body with a relatively simple means, and image deterioration due to the inclination of the discharge port array does not occur. High definition recording is possible.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 to 5 are explanatory views for explaining a preferred ink jet recording head to which the present invention is implemented or applied. Hereinafter, each component will be described with reference to these drawings.

  The ink jet recording head (recording head cartridge) of the present embodiment is positioned on a carriage 34 (FIG. 4) of the ink jet recording apparatus main body by positioning means, and is electrically connected and fixedly supported by contact of electrical contacts. At the same time, it is detachable from the carriage. Further, an ink tank is detachably attached to the ink jet recording head. This ink jet recording head is equipped with six ink tanks, and ink tanks for matte black, photo black, cyan, magenta, yellow, and gray inks are provided. Each of these ink tanks is detachable independently from the ink jet recording head, and can be individually replaced. With such a configuration, the ink tank can be replaced as appropriate, and the ink can be used without waste, so that the running cost of printing in the inkjet recording apparatus can be kept low.

Next, the ink jet recording head will be described in detail in order for each component constituting the ink jet recording head.
(1) Printhead body The printhead body uses a bubble jet (registered trademark) system that uses an electrothermal transducer that generates thermal energy to cause film boiling of ink in response to an electrical signal. is doing. Further, it is a so-called side shooter type in which the electrothermal converter and the ink discharge port are arranged to face each other.

  As shown in the exploded perspective view of FIG. 1, the recording head main body portion includes a recording element unit 20 and an ink supply unit 10.

  Further, as shown in FIG. 2, the recording element unit 20 includes a first recording element substrate 24a, a second recording element substrate 24b, a first plate 22, an electrical wiring tape (electrical wiring substrate) 26, and an electrical contact substrate. 25 and the second plate 23. The ink supply unit 10 includes an ink supply member 15, a flow path forming member 16, a joint seal member 11, a filter 13, and a seal rubber 14.

(1-1) Recording Element Unit The first plate 22 is a support substrate that supports the recording element substrates 24a and 24b, and is formed of, for example, an alumina (Al ₂ O ₃ ) material having a thickness of 2 to 6 mm. . The first plate 22 serves as an ink supply port for supplying one type of ink to the first recording element substrate 24a and for supplying the other five types of ink to the second recording element substrate 24b. And things are formed. Further, screwing portions for connection with the ink supply unit 10 are formed on both sides.

  In the first recording element substrate 24a, for example, an ink supply port which is a long groove-like through-hole serving as an ink flow path is formed in a row on a Si substrate having a thickness of 0.5 to 1 mm. On both sides of the ink supply port, the electrothermal conversion elements are arranged and arranged in a row, and an electric wiring (not shown) made of Al or the like for supplying electric power to the electrothermal conversion elements is formed. ing. These electrothermal conversion elements and electric wiring are formed by a film forming technique.

  The electrothermal conversion elements are arranged in a staggered manner in each row, that is, the positions of the ejection ports in each row are slightly shifted so as not to line up in a direction orthogonal to the row direction. Furthermore, electrode portions for supplying electric power to the electric wiring are formed along the outer sides of the electrothermal transducer, and bumps made of Au or the like are formed on the electrode portions. Yes.

  On the surface of the Si substrate on which these are formed, there is an ink channel wall that forms an ink channel corresponding to the electrothermal conversion element and a ceiling part that covers the ink channel wall. A structure made of a resin material having an outlet opened is formed by photolithography. The discharge ports are provided to face the electrothermal conversion elements, and form discharge port groups. In the first recording element, the ink supplied from the ink flow path is discharged from the discharge port facing each electrothermal conversion element by the pressure of the bubbles generated by the heat generated by each electrothermal conversion element. Each color has 512 discharge ports, and the discharge amount is 20 to 40 pl.

  The second recording element substrate 24b has the same configuration as that of the first recording element substrate 24a, but is different from the first recording element substrate 24a in that five ink supply ports are formed and one color is provided. There are 512 to 1536 discharge ports per one, and the discharge amount is 1 to 10 pl.

  The recording element substrate 24 is connected so that each ink supply port thereof communicates with each ink supply port of the first plate 22, and each is positioned with high accuracy with respect to the first plate 22. Bonded and fixed. The first adhesive used for the bonding is desirably a low viscosity, low curing temperature, cured in a short time, has a relatively high hardness after curing, and has ink resistance. For example, a thermosetting adhesive mainly composed of an epoxy resin is used as the first adhesive, and the thickness of the adhesive layer at that time is desirably 50 μm or less.

The second plate 23 is, for example, a single plate-like member having a thickness of 0.5 to 1 mm, and is made of alumina (Al ₂ O ₃ ). The first recording element substrate 24a and the second recording element substrate 24b, which are bonded and fixed to the first plate 22, have two openings larger than the respective outer dimensions. The second plate 23 is bonded to the first plate 22 with a second adhesive. As a result, when the electric wiring tape 26 is bonded, the electric wiring tape 26 comes into contact with the first recording element substrate 24a and the second recording element substrate 24b on the bonding plane and can be electrically connected. .

  The electric wiring tape 26 forms an electric signal path for applying an electric signal for ejecting ink to the first recording element substrate 24a and the second recording element substrate 24b. The electrical wiring tape 26 has two openings corresponding to the respective recording element substrates 24. In the vicinity of the edge of the opening, electrode terminals connected to the electrode portions of the respective recording element substrates 24 are formed. At the end of the electrical wiring tape 26, an electrical terminal connection portion for electrical connection with the electrical contact substrate 25 having an external signal input terminal for receiving an electrical signal is formed, and the electrode terminal and electrical terminal connection are formed. The parts are connected by a continuous copper foil wiring pattern.

  The electrical wiring tape 26 is bonded and fixed to the lower surface of the second plate 23 with a third adhesive on the back surface, and is further bent to one side of the first plate 22 and bonded and fixed to the side surface of the first plate 22. Has been. As the third adhesive, for example, a thermosetting adhesive having an epoxy resin as a main component and a thickness of 10 to 100 μm is used.

  The electrical connection between the electrical wiring tape 26 and the first recording element substrate 24a and the second recording element substrate 24b is achieved by, for example, thermal ultrasound between the electrode portion of the recording element substrate 24 and the electrode terminal of the electrical wiring tape 26. This is done by electrical bonding using a crimping method. The electrical connection portion between the first recording element substrate 24a and the second recording element substrate 24b and the electric wiring tape 26 is sealed with the first sealing agent and the second sealing agent. This protects the electrical connection part from ink corrosion and external impact. The first sealing agent is mainly used for sealing from the back side of the connection portion between the electrode terminal of the electric wiring tape 26 and the electrode portion of the recording element substrate 24 and sealing the outer peripheral portion of the recording element substrate 24. The second sealant is used for sealing from the front side of the connection portion.

  An electrical contact substrate 25 is electrically connected to the end of the electrical wiring tape 26 by thermocompression bonding using an anisotropic conductive film or the like. The electrical contact substrate 25 is formed with terminal positioning holes for positioning and terminal coupling holes for fixing.

(1-2) Ink Supply Unit As shown in FIG. 2, the ink supply member 15 is a component of the ink supply unit 10 for guiding ink from the ink tank to the recording element unit 20. The ink supply unit 15 is formed by resin molding, for example. A joint portion that is in contact with the ink supply port portion of the ink tank is provided at the bottom of the ink tank housing portion of the ink supply member 15. Here, a filter 13 for preventing entry of dust from the outside is joined by welding, and a seal rubber 14 is attached to prevent evaporation of ink from the joint portion. In the ink supply member 15, an ink flow path extending from the contact surface with the ink tank to the lower surface of the joint portion is formed.

  On the bottom surface of the ink supply member 15, a flow path forming member 16 having an ink introduction port for supplying ink to the recording element unit 20 is communicated with the ink introduction port and the ink flow path of the ink supply member 15. Positioned and attached by ultrasonic welding.

(1-3) Coupling of Recording Element Unit and Ink Supply Unit FIG. 3 is a perspective view showing a state after the recording element unit 20 and the ink supply unit 10 of the present invention are fixed with screws. The recording element unit 20 and the ink supply unit 10 have a joint seal member 11 provided with holes at positions corresponding to the ink supply port of the first plate 22 and the ink introduction port of the flow path forming member 15. It is clamped by two screws and fixed with pinching.

  The joint seal member 11 is made of an elastic material such as rubber, which has a low compression set, and is pressed between the ink supply port and the ink introduction port so that ink leakage does not occur. Can be communicated to.

(1-4) Mounting on Carriage As shown in FIG. 4, the ink jet recording head is mounted on the carriage 34 of the main body of the ink jet recording apparatus. The ink supply unit 10 and the recording element unit 20 are formed with a structure for mounting the inkjet recording head on the carriage 34 of the inkjet recording apparatus main body. That is, the ink supply unit 15 is provided with a mounting guide for guiding the ink jet recording head to the mounting position of the carriage 34 by contacting the corresponding part of the carriage 34. Further, at the upper part of the ink supply unit 10, there is provided an engaging portion for contacting the head set lever 33 on the main body side and mounting and fixing the ink jet recording head to the carriage 34.

  In order to suppress image deterioration such as band unevenness due to change in area factor due to tilt, ink discharge is perpendicular to the main scanning direction of the printer (second direction intersecting the first direction which is the conveyance direction of the recording medium). It is necessary to arrange the exit row with high accuracy. As an ink jet recording head, an abutting reference in the Y direction (the first direction described above) for contacting the corresponding portion of the carriage to position the ink jet recording head at a predetermined mounting position, and an ink ejection port array, that is, recording It is required to position and fix the element substrate vertically with high accuracy.

  In the ink jet recording head of the conventional example, the abutting reference in the Y direction is provided for the ink supply member 15 constituting the ink supply unit 10. Since the ink supply member 15 is made of resin, the strength cannot be ensured, and the ink supply member 15 may be deformed or may be displaced when the recording element unit 20 and the ink supply unit 10 are coupled with screws.

  On the other hand, in the present embodiment, as shown in FIG. 5A, the first plate 22 which is a support substrate for supporting the recording element substrate 24 constituting the recording element unit 20 is projected to the carriage in the Y direction. The abutting part 31 (first direction abutting part) was provided. The recording element substrate 24 is accurately stacked on the first plate 22 as a support substrate so as to be substantially orthogonal to the Y-direction abutting portion 31 used for mounting on the carriage by image processing.

  Since the Y-direction abutting portion, which is also a reference for mounting on the carriage, is used as a reference for image processing when the recording element substrate 24 is stacked, a high-precision stacking accuracy of the substrate remains as it is. Accuracy. In addition, since the ink supply member 15 is not affected by the deformation of the ink supply member 15 or the coupling accuracy between the ink supply unit 10 and the recording element unit 20, the ink discharge port array is highly accurate with respect to the abutting reference in the Y direction compared to the conventional method. Can be configured.

  The first plate 22 is made of a ceramic sintered body, which is alumina (Al 2 O 3) in this embodiment, and has extremely high rigidity compared to the resin, so that it is not deformed by an external force such as a mounting force on the carriage. High accuracy can be secured. Here, in the present embodiment, a resin carriage is used. This is to reduce the weight of the carriage and facilitate the main scanning operation.

  For this reason, in the present embodiment, high-strength ceramic alumina is used for abutting in the Y direction with respect to the resin carriage. Therefore, there is a concern that the corresponding portion of the carriage may be scraped during mounting. FIG. 5B is a side view in the direction of the arrow in FIG. 5A and shows a mounting locus of the Y-direction abutting portion 31 with respect to the corresponding portion of the carriage. Therefore, a concave step 32 is provided on the lower surface side (the front end surface of the mounting locus) of the Y-direction abutting portion 31 so that the Y-direction abutting portion 31 of the head does not scrape the carriage in the carriage mounting locus. Prevented edge interference. For this reason, even if the Y-direction abutting portion 31 is made of ceramic, it can be mounted with high accuracy without shaving the carriage.

  As described above, according to this embodiment, the Y-direction abutting portion of the ink supply member is provided by providing the Y-direction abutting portion used for positioning at the time of attachment to the carriage on the support substrate that supports the recording element substrate. The influence of the deformation of the part is suppressed. Further, the occurrence of inclination due to the influence of the assembly accuracy between the ink supply unit and the recording element unit can be suppressed. Therefore, the accuracy of the ink discharge port array in the scanning direction is improved. Further, since the support substrate is made of a ceramic sintered body such as alumina, the influence of deformation due to external force can be eliminated. In addition, for the concern that the ceramic abutting part scrapes the resin carriage during mounting, interference on the rotation locus can be avoided by the concave step on the lower surface of the abutting part.

  As described above, the recording head is accurately held with respect to the carriage, and image deterioration such as unevenness due to the dot formation position shift due to the inclination of the ejection port array can be suppressed.

1 is an exploded perspective view of an ink jet recording head according to an embodiment of the present invention. FIG. 2 is a further exploded exploded perspective view of the ink jet recording head of FIG. 1. FIG. 2 is a perspective view illustrating a state in which an ink supply unit and a recording element unit of the ink jet recording head of FIG. 1 are combined. FIG. 2 is a perspective view illustrating a relationship between a printer main body and an ink jet recording head according to an embodiment of the present invention. 5A is a bottom plan view of the ink jet recording head of FIG. 1, and FIG. 5B is a side view showing a mounting locus of the ink jet recording head of FIG. 1 on the carriage. It is an exploded perspective view of a conventional inkjet recording head. FIG. 7A is a perspective view of a conventional ink jet recording head, FIG. 7A shows a state where an ink tank is attached, and FIG. 7B shows a state where the ink tank is removed. It is a bottom plan view of a conventional inkjet recording head.

Explanation of symbols

22 First plate 23 Second plate 24a, 24b Recording element substrate 31 Y-direction abutting portion 32 Concave step 34 of Y-direction abutting portion Carriage 70 Recording head cartridge

Claims (4)

An ink jet recording apparatus having an ink jet recording apparatus having a carriage that moves in a second direction that intersects a first direction that is a conveyance direction of the recording medium, and that records ink droplets onto the recording medium. An ink jet recording head including an element substrate and a support substrate that supports the recording element substrate,
A first direction abutting portion used for positioning in the first direction when the inkjet recording head is attached to the carriage;
The first direction abutting portion is provided on the support substrate, and the first direction abutting portion has a concave step on the front end surface of the mounting locus to the carriage. Inkjet recording head.   The ink jet recording head according to claim 1, wherein the recording element substrate is provided on the support substrate with reference to the first direction abutting portion.   The inkjet recording head according to claim 1, wherein the support substrate is made of a ceramic sintered body.   4. The ink jet recording head according to claim 1, wherein the support substrate is made of alumina.

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