JP2004042474A - Ink jet recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent generation of troubles such as an image quality decrease, a cost increase, an increase of a recording apparatus size, an increase of power consumption, fixing dapples, yellowing of a material to be recorded, an increase of noise and an increase of a temperature rise time by a relatively simple arrangement while ink is enabled to be speedily fixed in the ink jet recording apparatus. <P>SOLUTION: In the ink jet recording apparatus which uses an ink jet recording head and records by jetting ink to a medium to be recorded, a conductor set opposite to the ink jet recording head, and the ink jet recording head are provided with exciting coils. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ink jet recording apparatus that discharges colored liquid droplets onto a recording material in accordance with print data, and more particularly, to a recording apparatus having a heating / drying unit for fixing a recording material.
[0002]
[Prior art]
The ink jet recording method is a method in which an image is formed by discharging a single color ink or a plurality of colors of ink corresponding to color recording onto a recording material (paper, cloth, OHP paper, printed circuit board, or the like). An ink jet recording apparatus employing this method includes a carriage on which a recording head and an ink tank are mounted, a transport section for transporting a recording material, and a control section for controlling these.
[0003]
Such an ink jet recording apparatus discharges ink droplets from a plurality of discharge ports while serially scanning a recording head in a direction (main scanning direction) substantially perpendicular to a conveying direction (sub-scanning direction) of a recording material. At the time of recording, the recording material is intermittently conveyed by an amount equal to the recording width to sequentially record on the recording material. Since this recording method is performed by directly discharging ink onto a recording material in accordance with a recording signal, it is already widely used as a high-speed, easy and inexpensive recording method, and has an advantage that it can also record on plain paper. , Its future potential is greatly expected.
[0004]
Since recording on plain paper has a lower ink absorption speed than dedicated paper having excellent ink absorbency, it is desirable to heat the recording material to promote fixing of the ink. In particular, when recording a color image, the amount of ink is large and fixing takes a long time as compared with the case of monochrome recording. Therefore, heating the recording material to promote fixing of the ink shortens the recording time. Is crucial above.
[0005]
As shown in FIG. 5, the fixing device used for this purpose is (1) a rotating body having a heater inside, that is, a fixing roller 30 is pressed against a recording material. A method of heating and drying a recording material, and a method of heating and drying a recording material by a guide plate (platen) 31 having a planar heater or a heater 32 in contact with the recording material as shown in FIG. (E.g., Japanese Patent No. 2575136, Japanese Patent No. 2461641, Japanese Patent Application Laid-Open No. 58-72460, Japanese Patent Application Laid-Open No. 62-135368, Japanese Patent Application Laid-Open No. 5-11200, Japanese Patent Application Laid-Open No. 5-104706, Japanese Patent Application JP-A-8-150706, JP-A-11-5178, JP-A-11-123816, etc.) and (3) a method of heating and drying a recording material by radiation emitted from a halogen lamp (for example, As shown in FIG. 7, (4) a method in which hot air is applied to a recording material by a fan 34 and a heater 32, and the material is heated and dried (FIG. 7). For example, JP-A-2761671, JP-A-5-338126, JP-A-9-164667, JP-A-8-314327, and (5) radiant heat and hot air are applied to a recording material by a halogen lamp and a fan, and the recording material is heated. -There was a method of drying (for example, JP-A-8-224871).
[0006]
By the way, the method using a roller has a drawback that it takes time until the fixing roller reaches a predetermined temperature, and the time from when the power of the ink jet recording apparatus is turned on until the start of recording, that is, a so-called temperature rise time is long. In order to shorten the temperature rise time, there has been proposed a method of heating and drying a recording material using a heating film 36 having a small heat capacity (6) as shown in FIG. I have.
[0007]
On the other hand, in the methods (3) and (5) using a halogen lamp, since the absorptance of radiant light differs depending on the ink color, fixing unevenness is likely to occur, and ink is applied on the surface of the recording material. There is a problem that the non-existing part is discolored yellow due to radiant heat. The fixing unevenness and the yellow discoloration problem due to the difference in the absorptivity can be solved by applying radiation light to the recording material from the back side of the ink-coated surface and heating and drying the recording material (for example, JP-A-9-164667 and JP-A-10-1998). No. 86353) has been proposed.
[0008]
(4) In the method using a fan, the generation of noise by the fan becomes a problem, and when blowing air on the ink-coated surface of the recording material, the undried ink flows due to the wind pressure. There was a problem of doing it.
[0009]
However, even if any of the methods (1) to (6) is used, a portion other than the ink-coated portion of the recording material is heated, so that there is a problem that the power is wasted correspondingly. Was.
[0010]
[Problems to be solved by the invention]
To solve the problem that extra power is consumed for heating and drying the recording material, for example, as shown in FIG. 19, (7) a plurality of small heating means and the power to the heating means are controlled. Means for controlling the power to the heating means according to the paper size and print density to reduce the power consumption for heating and drying (Japanese Patent Application Laid-Open No. H11-115175), and (8) A method in which a small heater for scanning is provided and only necessary parts are heated and dried (JP-A-6-238882). (9) A method in which waste heat generated from an optical system, a driving system, an electronic circuit, and the like is guided to a recording material by a fan. (JP-A-7-323533 and JP-A-8-258254) have been proposed.
[0011]
However, (7) the method using a plurality of heating means does not solve the problem of a long temperature rise time. Further, in (7), a plurality of small heating means are provided, and in (8) a method using a small heater for scanning on the surface of the recording material, a scanning mechanism for the small heater is provided, so that the structure of the recording apparatus itself becomes complicated. In any case, problems such as an increase in cost and an increase in the size of the recording apparatus are newly generated. In the method (9) using waste heat, there is a problem that the temperature rise time is required and the amount of generated heat is not controlled, so that the drying effect becomes incomplete.
[0012]
Further, there has been proposed a method of heating and drying only an ink-coated portion of a recording material. For example, (9) a method has been proposed in which a carriage is provided with a heater and a halogen lamp for heating / drying. However, in this method, the temperature of the recording nozzle is high, so that the ejection stability of the ink is reduced, The ink dries and causes nozzle clogging, all of which cause poor image quality. Also. (10) A method has been proposed in which a recording head is provided with a microwave generating means, and the ink on the recording material is irradiated with the microwave and heated and dried (JP-A-7-314661). Some of the microwaves heated the undischarged ink in the nozzles, which reduced the ejection stability of the inks and dried the inks in the nozzles, causing clogging of the nozzles, all of which could cause poor image quality. . Further, in order to avoid microwave exposure of the user of the recording apparatus, a microwave shielding means such as a wire mesh is necessary so that the microwave does not leak out of the apparatus, and there is a problem that the size of the recording apparatus is enlarged. .
[0013]
Further, in a so-called bubble jet (registered trademark) type ink jet printer that generates bubbles in the ink by using thermal energy and discharges the ink based on the generation of the bubbles, (11) an ink discharge head provided in the recording head is provided. A method has been proposed in which the heat of a heater is transmitted to a recording material by radiation or contact from a heat-dissipating fixing plate provided on the recording head and heated and dried (Japanese Patent Application Laid-Open Nos. 10-785 and 10-272778). However, this method has a problem in that the amount of generated heat is not controlled similarly to the method using waste heat in (9), so that the drying effect becomes incomplete.
[0014]
Therefore, the present invention has been made in view of the unsolved problems of the conventional technology, and can fix the ink quickly, while lowering the image quality, increasing the cost, increasing the size of the recording apparatus, and reducing the consumption. An object of the present invention is to provide an ink jet recording apparatus which does not cause problems such as an increase in power, occurrence of fixing unevenness, yellow discoloration of a recording material, an increase in noise, and an increase in temperature rise time.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, an ink jet recording apparatus according to the present invention is characterized in that a conductor provided to face the ink jet recording head, and the ink jet recording head includes an exciting coil.
[0016]
Preferably, control means for turning on or off the exciting coil is provided.
[0017]
Preferably, the control means includes a control means for turning on or off the exciting coil in accordance with a print density of the ink jet recording head.
[0018]
Preferably, the control means includes a control means for turning on or off the exciting coil in accordance with the type of the recording material.
[0019]
Preferably, the control means includes a control means for turning on or off the excitation coil in accordance with a print density of the ink jet recording head and a type of a recording material.
[0020]
More preferably, an alternating current of 20 kHz or more is applied to the exciting coil.
[0021]
(Action)
According to the above configuration, it is possible to quickly fix the ink by a simple and low-cost means in which the conductor provided opposite to the ink jet recording head and the ink jet recording head include an exciting coil. It is possible to prevent problems such as a decrease in image quality, an increase in cost, an increase in power consumption, an occurrence of fixing unevenness, yellow discoloration of the recording material, an increase in noise, and an increase in temperature rise time.
[0022]
Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. May be substituted.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
[0024]
FIG. 1 is a perspective view for explaining an example of an ink jet recording apparatus according to the present invention. The carriage 11 is moved by a carriage drive motor 13 via a carriage drive belt 14 in a direction perpendicular to the sheet passing direction of the recording material 12. The recording material is conveyed by a paper passing motor (not shown). The operations of the paper passing motor and the carriage drive motor are controlled by a control circuit (not shown). The discharge recovery unit 16 includes a discharge recovery pump (not shown), and when the ink jet recording head (not shown) is brought into contact with the discharge recovery pump, the recovery pump can suck ink. The ink jet recording apparatus includes a conductor 23 according to claims 1 and 2 of the present invention.
[0025]
FIG. 2 is a perspective view for explaining the shape of the conductor 23 as viewed from the opposite side of the recording head. The material of the conductor is a magnetic material such as nickel, stainless steel, and iron. A plurality of grooves 24 are provided on the opposite side of the conductor from the recording head. The groove 24 prevents heat transfer in the scanning direction of the carriage in the conductor, and increases the heating and drying efficiency of the recording material.
[0026]
FIG. 3 is a cross-sectional view for explaining the thickness t of the conductor 23 at the deepest portion of the groove. The same thickness t depends on the material of the same conductor. For example, nickel can have a high heating / drying efficiency of 120 μm or less for copper, 30 μm or less for copper, 400 μm or less for stainless steel, and 200 μm or less for iron. , These values are desirable.
[0027]
FIG. 4 is an enlarged view of the carriage portion viewed from the recording material direction. The ink droplet is ejected from a nozzle 20 provided on the inkjet recording head 19. The same number of ink jet recording heads and nozzles as the number of ink colors to be ejected are provided. The ink jet recording apparatus is provided with excitation coils 22 on both sides of the recording head according to claims 1 and 2 of the present invention.
[0028]
FIG. 5 is an enlarged view for explaining the structure of the exciting coil. The coil 26 is wound around the core 25. The core is preferably made of iron, ferrite, permalloy, or the like, having a relatively high magnetic attraction and a low residual magnetic flux density.
[0029]
FIG. 6 is a schematic diagram for explaining the operation of the exciting coil 22. In FIG. 1, the recording material 12, the exciting coil 22, and the recording head 19 are illustrated as being separated from each other for easy understanding, but they are actually installed at an interval of 1 mm or less. The excitation coil is supplied with an alternating current from an excitation coil application current control circuit (not shown), and repeatedly generates and eliminates a magnetic flux H around the excitation coil. When the fluctuating magnetic flux H crosses the conductor 23, an eddy current is generated inside the conductor so as to generate a magnetic field that prevents a change in the magnetic field. As a result, the conductor generates Joule heat. This Joule heat is transmitted to the recording material and heats and dries it. The alternating current frequency applied to the exciting coil is 20 kHz or more according to claim 6 of the present invention, because it exceeds the audible range of humans, so that no noise is generated at the time of energization. The excitation coil is installed toward the same location so that the ink droplet 21 discharged from the nozzle generates heat most efficiently near the location where the ink droplet reaches the recording material.
[0030]
FIG. 7 is a diagram showing a control flow of the exciting coil application current control circuit. This control flow is processed in parallel with an image forming flow (not shown). The control flow includes a control method for turning on or off the exciting coil in accordance with the print density of the ink jet recording head and the type of the recording material. When the paper supply is started, the exciting coil application current control circuit determines the type of recording material in step S1, and if the ink permeability is low, such as plain paper, proceeds to step S2. Conversely, the following processing is not performed for a sheet having a high ink permeability such as a coated sheet. When the ink is discharged in step S3 for determining the ink discharge, the process proceeds to step S4 for setting the exciting coil application current amount. If the ink is not ejected, the process proceeds to step S6 for determining the end of sheet feeding. In step S4, the optimum amount of applied current is determined based on the ink ejection density and the type of the recording material. In step S5, the position of the exciting coil is detected, and the process proceeds to step S6. In step S6, if the exciting coil is located above the ink discharge point, the process proceeds to step S7, and if not, the process returns to step S5. In step S7, an optimal amount of current is applied to the exciting coil 22. In step S8, if the sheet feeding has been completed, the above processing is ended, and if not, the process returns to step S3.
[0031]
(Second embodiment)
Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings.
[0032]
In the first embodiment, the exciting coils 22 are provided on both sides of the recording head 19, but the exciting coils may be provided inside the recording head.
[0033]
FIG. 8 is a perspective view for explaining an example of an ink jet recording apparatus in which the excitation coil is installed inside the recording head. The ink jet recording apparatus includes a conductor 23 according to claims 1 and 2 of the present invention. FIG. 8 is the same as FIG. 1 except that the location of the exciting coil, which will be described later, is different, so that the description is omitted. Further, the material and structure of the conductor 23 are the same as those of the first embodiment, and the description is omitted.
[0034]
FIG. 9 is an enlarged view of the carriage portion viewed from the recording material direction. Since the ink jet recording apparatus is the same as FIG. 4 except that an exciting coil 22 is provided between the recording heads according to claims 1 and 2 of the present invention, the description is omitted. The function of the exciting coil, the structure of the exciting coil, and the control flow of the exciting coil application current control circuit applied to the exciting coil are the same as those in the first embodiment, and therefore, the description thereof is omitted.
[0035]
(Third embodiment)
Hereinafter, a third embodiment of the present invention will be described in detail with reference to the drawings.
[0036]
In the first and second embodiments, the exciting coil 22 is provided on the recording head 19 side. However, the core of the exciting coil may be hollow and the recording head may be included.
[0037]
FIG. 10 is a perspective view for explaining an example of an ink jet recording apparatus in which the excitation coil includes the recording head. The ink jet recording apparatus includes a conductor 23 according to claims 1 and 2 of the present invention. FIG. 10 is the same as FIG. 1 except that the location of the exciting coil, which will be described later, is different, so that the description is omitted. Further, the material and structure of the conductor 23 are the same as those of the first embodiment, and the description is omitted.
[0038]
FIG. 11 is an enlarged view of the carriage portion viewed from the recording material direction. The ink jet recording apparatus includes an exciting coil 22 according to claims 1 and 2 of the present invention. The excitation coil is the same as that of FIG. 4 except that it includes the recording head 19, and therefore, the description is omitted.
[0039]
FIG. 12 is an enlarged view for explaining the excitation coil and the recording head. The core 25 is hollow and contains the recording head 19. A coil 26 is wound around the core. Since the material of the core is the same as that of the first embodiment, the description is omitted.
[0040]
FIG. 13 is a schematic diagram for explaining the function of the exciting coil. In FIG. 1, the recording material 12, the exciting coil 22, and the recording head 19 are shown separated from each other for the sake of simplicity. However, they are actually installed at intervals of 1 mm or less. The excitation coil is supplied with an alternating current from an excitation coil application current control circuit (not shown), and repeatedly generates and eliminates a magnetic flux H around the excitation coil. When the fluctuating magnetic flux H crosses the conductor 23, an eddy current is generated inside the conductor so as to generate a magnetic field that prevents a change in the magnetic field. As a result, the conductor generates Joule heat. The alternating current frequency applied to the exciting coil is 20 kHz or more according to claim 6 of the present invention, because it exceeds the audible range of humans, so that no noise is generated at the time of energization.
[0041]
FIG. 14 is a diagram showing a control flow of the exciting coil application current control circuit. This control flow is processed in parallel with an image forming flow (not shown). The control flow includes a control method for turning on or off the exciting coil in accordance with the print density of the ink jet recording head and the type of the recording material. When the paper supply is started, the exciting coil application current control circuit determines the type of recording material in step S1, and if the ink permeability is low, such as plain paper, proceeds to step S2. Conversely, the following processing is not performed for a sheet having a high ink permeability such as a coated sheet. When the ink is discharged in step S3 for determining the ink discharge, the process proceeds to step S4 for setting the exciting coil application current amount. If the ink is not ejected, the process proceeds to step S6 for determining the end of sheet feeding. In step S4, an optimal amount of applied current is determined based on the ink ejection density and the type of recording material. In step S5, an optimal amount of current is applied to the exciting coil 22. In step S6, if the sheet feeding has been completed, the above processing is ended, and if not, the process returns to step S3. In the third embodiment, since the recording material can be heated and dried at the same time as the ink discharge, the heating and drying can be performed more quickly than in the first and second embodiments.
[0042]
【The invention's effect】
As described above, the ink jet recording apparatus according to the present invention heats and dries only the portion of the recording material to which the ink is applied, so that the ink can be quickly fixed, while lowering the image quality, increasing the cost, It is possible to prevent problems such as an increase in the size of the recording apparatus, an increase in power consumption, the occurrence of fixing unevenness, yellow discoloration of the recording material, an increase in noise, and an increase in temperature rise time.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating an example of a configuration of a recording apparatus according to a first embodiment of the present invention.
FIG. 2 is an enlarged view for explaining a structure of a conductor of the recording apparatus according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view for explaining a structure of a conductor of the recording apparatus according to the first embodiment of the present invention.
FIG. 4 is a perspective view illustrating an example of a configuration of a carriage of the recording apparatus according to the first embodiment of the present invention.
FIG. 5 is a diagram for explaining an example of a configuration of an exciting coil of the recording apparatus according to the first embodiment of the present invention.
FIG. 6 is a schematic diagram for explaining the function of an exciting coil of the recording apparatus according to the first embodiment of the present invention.
FIG. 7 is a flowchart for explaining a control method of a heating / fixing mechanism of the recording apparatus according to the first embodiment of the present invention.
FIG. 8 is a perspective view illustrating an example of a configuration of a recording apparatus according to a second embodiment of the present invention.
FIG. 9 is a perspective view illustrating an example of a configuration of a carriage of a recording apparatus according to a second embodiment of the present invention.
FIG. 10 is a perspective view illustrating an example of a configuration of a recording apparatus according to a third embodiment of the present invention.
FIG. 11 is a perspective view illustrating an example of a configuration of a carriage of a recording apparatus according to a third embodiment of the present invention.
FIG. 12 is a diagram illustrating an example of a configuration of an exciting coil of a recording apparatus according to a third embodiment of the present invention.
FIG. 13 is a schematic diagram for explaining the function of an exciting coil of a recording apparatus according to a third embodiment of the present invention.
FIG. 14 is a diagram showing a control flow of an exciting coil application current control circuit.
FIG. 15 is a perspective view for explaining an example of the configuration of a conventional recording apparatus having a rotating body having a heating element therein.
FIG. 16 is a perspective view illustrating an example of a configuration of a recording apparatus including a conventional guide plate (platen) including a planar heater or a heating element.
FIG. 17 is a perspective view illustrating an example of a configuration of a recording apparatus including a conventional fan.
FIG. 18 is a perspective view illustrating an example of a configuration of a recording apparatus including a conventional heating film.
FIG. 19 is a perspective view illustrating an example of a configuration of a conventional recording apparatus including a plurality of rotating bodies each including a heating element therein.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Carriage 12 Recording material 13 Carriage drive motor 14 Carriage drive belt 15 Carriage drive rail 16 Discharge recovery part 17, 18 Conveyance roller 19 Inkjet recording head 20 Nozzle 21 Ink droplet 22 Excitation coil 23 Conductor 24 Groove 25 Core 26 Coil 30 Fixing roller 31 Guide plate 32 Heater 33 Motor 34 Fan 35 Heating body 36 Heating film 37 Heating film guide roller

Claims (7)

Using an inkjet recording head provided with a scanning unit that scans in a direction orthogonal to the transport direction of the recording material,
Among ink jet recording apparatuses that perform recording by discharging ink on a recording material,
In an inkjet recording apparatus having heating means for drying an ink image formed on the recording material by the inkjet recording head,
An ink jet recording apparatus, wherein the heating means is an excitation coil provided on the ink jet recording head and a conductor provided opposite the ink jet recording head. An ink jet recording apparatus comprising: a control unit for turning on or off the exciting coil in accordance with a printing situation of the ink jet recording head. 3. The ink jet recording apparatus according to claim 2, wherein the control unit includes a control unit that turns on or off the exciting coil in accordance with a print density of the ink jet recording head. 3. The ink jet recording apparatus according to claim 2, wherein the control unit includes a control unit that turns on or off the exciting coil according to a type of the recording material. 3. The ink jet recording apparatus according to claim 2, wherein the control unit includes a control unit for turning on or off the exciting coil in accordance with a print density of the ink jet recording head and a type of a recording material. . 6. The ink jet recording apparatus according to claim 1, wherein an alternating current of 20 kHz or more is applied to the exciting coil. 7. The inkjet recording according to claim 1, wherein the inkjet recording head generates bubbles in the ink by using thermal energy and discharges the ink based on the generation of the bubbles. apparatus.

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