JP4475777B2 - Inkjet printer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet printer that forms an image or the like by depositing ink droplets on a recording sheet in a predetermined pattern.
[0002]
[Prior art]
Conventionally, an ink jet printer has been used as a recording apparatus for forming an image or the like on recording paper.
[0003]
In such an ink jet printer recording method, ink droplets are ejected toward the recording paper using heat energy generated by a heating element, using a deformation of a piezoelectric element, and further accompanied by irradiation of electromagnetic waves. Among them, the thermal jet type using the heat energy of the heating element is easy to form the heating element and even a heating element with a small area is used. Since relatively large heat energy can be generated, it is attracting attention as being suitable for high-density recording.
[0004]
As such a thermal jet type ink jet printer, for example, as shown in FIG. 3, a plurality of heating elements 23 are provided on the upper surface of a substrate 22, and a plurality of ink discharge holes corresponding to the heating elements 23 are formed on the substrate 21. The nozzle member 24 having 25 is disposed with a predetermined interval therebetween, and the ink jet head 21 in which the gap between the substrate 22 and the nozzle member 24 is filled with the ink 26 and the recording paper M are used as the nozzle member 24. It is known to include a transport roller 27 for transporting the ink on the ink discharge hole 25 and a platen 29 disposed at a position facing the ink jet head 21, using the transport roller 27 and the like. While supplying the recording paper M between the ink ejection holes 25 of the inkjet head 21 and the platen 29, the heating element 23 is converted into image data. Then, the heat A is selectively generated, and bubbles A are generated in the ink 26 by the heat energy, and a part of the ink 26 is externally discharged from the ink discharge holes 25 of the nozzle member 24 by the pressure of the generated bubbles A. A predetermined image is recorded by discharging the ink to the recording paper M and causing it to adhere to the recording paper M.
[0005]
The platen 29 is for supporting the recording paper M supplied onto the ink jet head 21 from behind, and is arranged at a predetermined interval from the outer surface of the nozzle member 24.
[0006]
Further, on the downstream side of the recording head M in the transport direction with respect to the ink jet head 21, a transport roller 28 for guiding the recording paper M after ink adhesion to the discharge portion of the printer main body is disposed.
[0007]
[Problems to be solved by the invention]
By the way, according to the conventional ink jet printer described above, the transport rollers 27 and 28 for transporting the recording paper M are arranged on both sides of the ink jet head 21 so as to support the recording paper M on the ink jet head 21. Since the only thing to do is the platen 29, the running of the recording paper M tends to be unstable on the ink jet head 21, and when the recording paper M is conveyed at high speed, the surface roughness of the recording paper M is localized. Due to the difference, the recording paper M may cause “flickering” between the inkjet head 21 and the platen 29. When such “fluttering” occurs, it is difficult to land the ink accurately on a predetermined position of the recording paper M, and there is a defect that the image is distorted and the image becomes unclear.
[0008]
Further, in the above-described conventional ink jet printer, there is no support for the recording paper M after the trailing edge of the recording paper M has passed the position of the conveying roller 27. The distance between the paper M and the ink-jet head 21 changes, which causes a disadvantage that a desired image cannot be obtained. In order to prevent such a disadvantage, the recording area is changed from the rear end of the recording paper M to the recording area. If the distance to the final line is set to be long, the margin area of the recording paper M becomes wide, and the disadvantage that the recording paper M is wasted is induced.
[0009]
The present invention has been devised in view of the above-described drawbacks, and the object of the present invention is to reduce the “flutter” of the recording paper even when the recording paper is conveyed at high speed, and to obtain a clear and good image. An object is to provide a highly reliable inkjet printer.
[0010]
[Means for Solving the Problems]
An ink jet printer according to the present invention, provided with a heating element on the upper surface of the substrate, on the substrate, the nozzle member having an ink discharge hole, disposed at a predetermined interval, between the substrate and the nozzle member of the ink jet head formed by filling the ink into the gap, in an ink jet printer including a conveying means, for conveying the recording sheet on the ink discharge hole of the nozzle member, said ink-jet head, thermal conductivity 1. with 0 W / m · K or more in which the guide member is mounted, in sliding contact on the recording paper in the guide member upstream side of the recording paper with respect to the ink discharge hole, stored in said ink jet head It is configured to conduct a part of heat to the recording paper through the guide member .
[0011]
Further, in the ink jet head of the present invention, the guide member is formed by a metal, and may be grounded.
[0013]
Further, in the ink jet head of the present invention, the the conveying means and the guide member is provided with opposed, the recording sheet is configured to close contact with the guide member by said conveying means Also good .
In the inkjet head of the present invention, a driver IC may be mounted on the substrate, and the driver IC may be covered by the guide member.

[0014]
According to the ink jet printer of the present invention, the recording paper supplied onto the ink jet head is well supported by a guide member or the like in the vicinity of the ink jet head, and the recording paper travels stably. Even in this case, there is almost no occurrence of “flutter” of the recording paper on the ink-jet head, and distortion or the like is caused by accurately landing the ink droplets ejected from the ink ejection holes at predetermined positions on the recording paper. It is possible to form a clear image with little.
[0015]
Further, according to the ink jet printer of the present invention, the running of the recording paper supplied onto the ink ejection holes of the ink jet head is stabilized as described above, so that the rear end of the recording paper is curled. In addition, the rear end portion of the recording paper is satisfactorily supported by a guide member or the like until immediately before being supplied onto the ink ejection holes. Accordingly, the distance from the trailing edge of the recording paper to the final line of the recording area can be set short, and the blank area provided on the trailing edge of the recording paper can be reduced.
[0016]
Further, according to the ink jet printer of the present invention, the guide member is made of metal and kept at a ground potential, so that even if the recording paper supplied onto the ink jet head is charged with static electricity. These electric charges are easily released to the ground potential via the guide member. Therefore, the recording paper is not attracted to the ink jet head side due to the electrostatic attraction described above, and this can effectively prevent the fluctuation of the distance between the ink jet head and the recording paper.
[0017]
Furthermore, according to the ink jet printer of the present invention, the guide member is made of a metal having a thermal conductivity of 1.0 W / m · k or more, so that the heat accumulated in the ink jet head with the use of the ink jet head can be reduced. The portion is satisfactorily conducted to the recording paper before printing through the guide member or the like, and the recording paper can be warmed in advance. In this case, drying of the ink adhering to the recording paper is accelerated, and for example, high-speed recording with a printing cycle of 0.8 msec / Line or less can be sufficiently handled.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a diagram showing a configuration of an ink jet printer according to an embodiment of the present invention. The ink jet printer shown in FIG. 1 generally includes an ink jet head 1 and a transport roller 10 as a transport means. Has been.
[0019]
The ink jet head 1 is based on a substrate 2 made of an electrically insulating material such as alumina ceramics, and supports the heat generating element 3, the electrode 4, the nozzle member 7 and the like on the upper surface thereof.
[0020]
When the substrate 2 is made of, for example, alumina ceramics, an appropriate organic solvent or solvent is added to and mixed with ceramic raw material powders such as alumina, silica, and magnesia to form a slurry. A ceramic green sheet is obtained by adopting a calender roll method or the like, and thereafter, the ceramic green sheet is punched into a predetermined shape and then fired at a high temperature so as to form a predetermined rectangular shape.
[0021]
Further, a glaze layer (not shown) is deposited and formed on the upper surface of the substrate 2 over the entire surface, and a plurality of heating elements 3 are electrically connected to both ends of the heating elements 3 on the upper surface of the glaze layer. The electrode 4 is attached.
[0022]
The plurality of heating elements 3 are linearly arranged in the main scanning direction at a dot density of, for example, 600 dpi (dot per inch), and are formed of an electric resistance material such as Ta—SiO _2. When the power supply is applied via, Joule heat is generated, and a predetermined temperature necessary to form the bubbles A in the ink 8 is reached.
[0023]
The heating element 3 is formed by employing a conventionally well-known thin film forming technique, specifically, a sputtering method, a photolithography technique, and an etching technique, and processing the above-described electric resistance material into a predetermined pattern.
[0024]
Further, a protective film 5 is deposited on the upper surfaces of the heat generating element 3 and the electrode 5, and the heat generating element 3 and the electrode 4 are covered with the protective film 5.
[0025]
The protective film 5 is made of an inorganic material such as silicon nitride, and protects the heat generating element 3 and the electrode 4 from corrosion caused by contact with moisture contained in the ink 9.
[0026]
Further, a nozzle member 6 having a plurality of ink ejection holes 7 is disposed on the substrate 2 in parallel with the substrate 2 with a predetermined interval therebetween.
[0027]
The nozzle member 6 is placed on the substrate 2 via a spacer (not shown), whereby a gap of about 10 μm to 100 μm is provided between the nozzle member 6 and the substrate 2.
[0028]
The ink discharge holes 7 of the nozzle member 6 are disposed above the heat generating element 3 so as to discharge ink droplets toward the recording paper during the recording operation of the ink jet head, and correspond to the heat generating element 3 on a one-to-one basis. Thus, they are arranged at a predetermined density over the main scanning direction.
[0029]
The nozzle member 6 is made of a resin material such as polyimide resin or epoxy resin, and a liquid precursor of these resin materials is applied to the upper surface of the substrate using a dispenser or the like, and this is applied to a well-known photolithography technique and etching. It is formed by adopting technology and processing it into a predetermined shape.
[0030]
Further, the gap formed between the substrate 2 and the nozzle member 6 is filled with ink 8.
[0031]
As the ink 8, for example, pigment-type oil-based ink or water-based dye ink is used. The ink 8 is supplied between the substrate 2 and the nozzle member 6 from an ink tank (not shown), When a bubble A is generated in the ink 8, a part of the ink 8 becomes an ink droplet and is discharged from the ink discharge hole 7 to the outside by the pressure of the bubble A.
[0032]
And the guide member 9 is attached to the inkjet head 1 mentioned above.
The guide member 9 is made of a metal such as aluminum or stainless steel into a predetermined shape, and is fixed to the inkjet head 1 by screwing or the like.
[0033]
The guide member 9 is in sliding contact with the recording paper M on the upstream side in the transport direction of the recording paper M with respect to the ink ejection holes 7, and a part of the guide member 9 is in contact with the recording paper M near the ink ejection holes 7. Thus, the distance between the ink ejection holes 7 and the recording paper M can be kept substantially constant.
[0034]
On the other hand, the transport roller 10 is configured by winding a material having a high friction coefficient around a support rod made of metal, for example, rubber having a hardness of 30 ° to 60 °, for example, and faces the guide member 9 described above. At the position, the guide member 9 is disposed in a pressure contact state.
[0035]
In addition to the function of conveying the recording paper M in a predetermined direction, the conveying roller 10 has a function of satisfactorily bringing the recording paper M into close contact with the guide member 9 and is driven at a predetermined feeding speed by a drive motor (not shown). Rotated and driven.
[0036]
As described above, the ink jet printer of the present embodiment described above supplies the heating element 3 of the ink jet head 1 to the image while supplying the recording paper M onto the ink discharge hole 7 of the ink jet head 1 via the guide member 9 and the conveying roller 10. Based on the data, heat is selectively generated individually, and bubbles A are generated in the ink 9 by this thermal energy, and a part of the ink 9 is partially discharged by the pressure generated by the generated bubbles A. A predetermined image is recorded by discharging the ink to the outside and attaching it to the recording paper M.
[0037]
According to the ink jet printer of the present embodiment as described above, since the recording paper M is supported in the vicinity of the ink discharge holes 7 by the guide member 9 and the conveying roller 10, the running state of the recording paper M is stabilized. The distance between the ink discharge hole 7 and the recording paper M is kept substantially constant. For this reason, even when the recording paper M is transported at a high speed, there is almost no “flutter” of the recording paper M on the inkjet head 1, and the ink droplets ejected from the ink ejection holes 7 are recorded on the recording paper. By accurately landing at a predetermined position of M, it is possible to form a clear image with little distortion.
[0038]
Further, in this case, since the traveling of the recording paper M supplied onto the ink ejection holes 7 of the inkjet head 1 is stabilized as described above, even when the trailing edge of the recording paper M is curled, The recording paper M is satisfactorily supported by the guide member 9 and the transport roller 10 until just before being supplied onto the ink ejection holes 7. Therefore, the distance from the trailing edge of the recording paper M to the last line of the recording area can be set short, and the blank area provided on the trailing edge side of the recording paper M can be reduced.
[0039]
Furthermore, if the guide member 9 is formed of a metal such as aluminum or stainless steel and is held at a ground potential by connecting it to a ground wiring, the recording paper M supplied onto the inkjet head 1 is used. Even when static electricity is charged, these charges can be released to the ground potential through the guide member 9 satisfactorily. Therefore, the recording paper M is not attracted to the ink jet head 1 side by electrostatic attraction, and this can effectively prevent the fluctuation in the distance between the ink jet head 1 and the recording paper M. Therefore, it is preferable that the guide member 9 is made of metal and kept at the ground potential.
[0040]
Furthermore, if the guide member 9 is formed of a metal having a thermal conductivity of 1.0 W / m · K or more, such as aluminum or stainless steel, the heat accumulated in the inkjet head 1 as the inkjet head 1 is used. Part of the recording paper M can be satisfactorily conducted to the recording paper M before printing through the guide member 9 and the like, and the recording paper M can be warmed in advance. In this case, drying of the ink 9 attached to the recording paper M is accelerated, and for example, high-speed recording with a printing cycle of 0.8 msec / Line or less can be sufficiently handled. Therefore, the guide member 9 is preferably formed of a metal having a thermal conductivity of 1.0 W / m · k or more.
[0041]
In addition, this invention is not limited to the above-mentioned form, A various change, improvement, etc. are possible in the range which does not deviate from the summary of this invention.
[0042]
For example, when the driver IC 11 is mounted on the substrate 2 of the inkjet head 1 in the above-described embodiment, the driver IC 11 may be configured to be covered with the guide member 9 as shown in FIG. Since the member 9 also serves as a cover member for the driver IC 11, the overall structure of the ink jet head 1 can be reduced in size as compared with a case where a cover member for the driver IC 11 is separately attached.
[0043]
Further, in the above-described embodiment, on both sides of the ink jet head 1, to feed the recording paper M between the guide member 9 and the transporting roller 10 and the recording paper M after ink adhesion to the discharge portion of the printer main body. The transport roller may be provided separately, or a platen 20 for supporting the recording paper M from behind may be disposed at a position facing the ink ejection holes 7 of the inkjet head 1.
[0044]
Further, in the above-described embodiment, the transport roller 10 is used as the transport unit. However, instead of this, a plurality of gears arranged in the main scanning direction may be used as the transport unit.
[0045]
【The invention's effect】
According to the ink jet printer of the present invention, the recording paper supplied onto the ink jet head is well supported by a guide member or the like in the vicinity of the ink jet head, and the recording paper travels stably. Even in this case, there is almost no occurrence of “flutter” of the recording paper on the ink-jet head, and distortion or the like is caused by accurately landing the ink droplets ejected from the ink ejection holes at predetermined positions on the recording paper. It is possible to form a clear image with little.
[0046]
Further, according to the ink jet printer of the present invention, the running of the recording paper supplied onto the ink ejection holes of the ink jet head is stabilized as described above, so that the rear end of the recording paper is curled. However, the recording paper is favorably supported by the guide member or the like until just before being supplied onto the ink ejection holes. Accordingly, the distance from the trailing edge of the recording paper to the final line of the recording area can be set short, and the blank area provided on the trailing edge of the recording paper can be reduced.
[0047]
Further, according to the ink jet printer of the present invention, the guide member is made of metal and kept at a ground potential, so that even if the recording paper supplied onto the ink jet head is charged with static electricity. These electric charges are easily released to the ground potential via the guide member. Therefore, the recording paper is not attracted to the ink jet head side due to the electrostatic attraction described above, and this can effectively prevent the fluctuation of the distance between the ink jet head and the recording paper.
[0048]
Furthermore, according to the ink jet printer of the present invention, the guide member is made of a metal having a thermal conductivity of 1.0 W / m · k or more, so that the heat accumulated in the ink jet head with the use of the ink jet head can be reduced. The portion is satisfactorily conducted to the recording paper before printing through the guide member or the like, and the recording paper can be warmed in advance. In this case, drying of the ink adhering to the recording paper is accelerated, and for example, high-speed recording with a printing cycle of 0.8 msec / Line or less can be sufficiently handled.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a configuration of an ink jet printer according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating a configuration of an inkjet printer according to another embodiment of the present invention.
FIG. 3 is a diagram illustrating a configuration of a conventional inkjet printer.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inkjet head, 2 ... Board | substrate, 3 ... Heat generating element, 6 ... Nozzle member, 7 ... Ink ejection hole, 8 ... Ink, 9 ... Guide member, 10 * ..Conveying means (conveying rollers)

Claims (4)

Provided with a heating element on the upper surface of the substrate, on the substrate, the nozzle member having an ink discharge hole, disposed at a predetermined interval, the ink was filled into the gap between the substrate and the nozzle member an ink jet head comprising Te, and conveying means for conveying the recording sheet on the ink discharge hole of the nozzle member, in an ink jet printer having a,
Said ink-jet head, together with the guide member thermal conductivity of 1.0 W / m · K or more is attached, the recording sheet conveyance direction upstream side of the recording paper the guide member with respect to the ink discharge hole An ink jet printer configured to conduct a part of heat accumulated in the ink jet head to the recording paper through the guide member .   The inkjet printer according to claim 1, wherein the guide member is made of metal and grounded. 3. The structure according to claim 1, wherein the conveying unit and the guide member are provided to face each other, and the recording unit is configured to closely contact the guide member by the conveying unit. The inkjet printer as described. 4. The ink jet printer according to claim 1, wherein a driver IC is mounted on the substrate, and the driver IC is covered by the guide member.

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