JP2007144848A - Image-forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device capable of stably conveying recording media at high speed without generating malfunction such as jam. <P>SOLUTION: A planar plate shape table 22 supporting the recording medium P from under the under face is constituted of a planar plate shape table upper section 26 where the suction holes 27 penetrating through in a location where the medium moves on an image recording area R are arranged and a table lower section 23 where a barrier wall 25 dividing the suction holes 27 arranged in the table upper section 26 a peripheral portion E and the portion C other than that from the lower face is arranged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly, to an image forming apparatus that forms an image on a recording medium supported by a recording medium support unit.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus is known as an image forming apparatus capable of printing on various recording media including plain paper. An ink jet recording apparatus records ink by directly ejecting ink onto a recording medium from an ejection port (hereinafter referred to as a nozzle) provided on a surface of the recording head that faces the recording medium, and landing, penetrating, or fixing on the recording medium. A recording apparatus forms an image on a medium. Such an ink jet recording apparatus has very excellent characteristics in terms of process simplicity, quietness during printing, formed image quality, and the like.

  In recent years, when a material such as a resin or metal that does not absorb ink is used as a recording medium of an ink jet recording apparatus, an active energy ray curable ink is often used to fix the ink on the recording medium. An inkjet recording apparatus using an active energy ray-curable ink is usually provided with an ultraviolet irradiation device that irradiates an active energy ray to cure the ink, and landed on a recording medium from the light source of the ultraviolet irradiation device. The ink is cured and fixed on the recording medium by irradiating the ink with ultraviolet rays having an active energy amount that cures the ink, thereby forming an image.

  However, in such an ink jet recording apparatus, since the end of the recording medium is easily bent due to heat generated by irradiation of active energy rays or moisture due to natural leaving of the recording medium, the recording medium in this state is transported. , Such as a jam is likely to occur.

  For this reason, a technique has been disclosed in which a suction hole is provided in a transport belt for transporting a recording medium, and the recording medium is transported while being sucked from the suction hole to the transport belt (see, for example, Patent Document 1).

Further, a technique for preventing the end of the recording medium from floating by pressing the end of the recording medium with an auxiliary roller has been disclosed (for example, see Patent Document 2).
JP 2002-103598 A JP 2001-278498 A

  However, as disclosed in Patent Document 1, the means for sucking and transporting the entire recording medium with a uniform force is used when the recording medium is transported at a high speed and in a narrow space due to a change in the flow of wind due to transportation. There is a problem that the end portion of the glass tends to float.

  Further, as in Patent Document 2, the means for pressing the end of the recording medium with the auxiliary roller has a problem that an image cannot be formed at the pressed position.

  The present invention has been made in view of the above points, and has an object to provide an ink jet recording apparatus capable of stably transporting a recording medium at high speed without causing a failure such as a jam. To do.

In order to solve such a problem, the invention described in claim 1
In an image forming apparatus for forming an image on a recording medium held on a recording medium support by a suction force using a suction device,
The portion that holds the peripheral portion of the recording medium by the recording medium support portion is provided with more suction holes that penetrate the recording medium support portion than the other portions.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the suction force is controlled by at least one of the number of the suction holes or the hole diameter.

The invention according to claim 3 is the image forming apparatus according to claim 1 or 2,
A suction device for sucking a peripheral portion of the recording medium, and a suction device for sucking a portion other than the peripheral portion,
The suction force of the suction device that sucks the peripheral portion of the recording body is larger than the suction force of the suction device that sucks a portion other than the peripheral portion.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the suction device is mounted other than the recording medium support portion. .

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the suction force at the periphery of the recording medium corresponds to a different size of the recording medium. It is characterized by that.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the recording medium support portion has a honeycomb structure.

According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects,
The ink is an active energy ray-curable ink that is cured by irradiation with an active energy ray,
An irradiating device for irradiating the active energy ray-curable ink discharged onto the recording medium with an active energy ray by light is provided.

  The invention according to claim 8 is the image forming apparatus according to claim 7, wherein the irradiation device is an ultraviolet irradiation device.

  According to the first aspect of the present invention, since the recording medium is held by the recording medium support portion in proportion to the suction force received from the back surface, the peripheral portion of the recording medium has a stronger suction force than the other portions. It is strongly held, and there is an effect of reducing the occurrence of floating and peeling of the end of the recording medium. Also, there is an effect that it is possible to prevent a failure of the image recording apparatus such as a jam due to the floating or peeling of the recording medium.

  According to the second aspect of the present invention, since the suction force can be controlled by the number of suction holes and the hole diameter, appropriate suction corresponding to the type and size of the recording medium and the moving speed of the recording medium. The effect which can be made into power is produced.

  According to the third aspect of the present invention, the suction device having different suction force is provided, and the suction device having a strong suction force is used in the peripheral portion of the recording medium, so that the peripheral portion is stronger than the central portion of the recording medium. The effect which can attach holding force is produced.

  According to the fourth aspect of the present invention, since the suction device is mounted in addition to the recording medium support portion, the recording medium support portion becomes light and can be transported at high speed.

  According to the fifth aspect of the present invention, even when recording media having different sizes are used, there is an effect that the suction force of the peripheral portion can be increased corresponding to the size of the recording media.

  According to the invention described in claim 6, since the recording medium support portion using the honeycomb structure is lightweight and has high strength, there is an effect that it can be stably conveyed at high speed.

  According to the seventh aspect of the present invention, when an image is formed by the image forming apparatus using the active energy ray-curable ink, the peripheral portion of the recording medium is supported by the recording medium with a stronger suction force than the other portions. Therefore, it is possible to reduce the lifting of the end portion of the recording medium and to prevent a failure of the image recording apparatus such as a jam.

  According to the eighth aspect of the present invention, when an image is formed by the image forming apparatus using the ultraviolet irradiation device, the peripheral portion of the recording medium is held by the recording medium support portion with a stronger suction force than the other portions. Therefore, it is possible to reduce the lifting of the end portion of the recording medium and to prevent a failure of the image recording apparatus such as a jam.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiments described below are provided with various technically preferable limitations for carrying out the present invention, but the scope of the invention is not limited to the embodiments and the illustrated examples.

  FIG. 1 is a perspective view showing a schematic configuration of an image forming apparatus according to the present invention, and FIG. 2 is a cross-sectional view showing a schematic configuration of the image forming apparatus according to the present invention. In this embodiment, an example in which the image forming apparatus is an inkjet recording apparatus will be described.

As shown in FIG. 1, the ink jet recording apparatus 1 according to this embodiment includes a support base 5 having a shape in which an upper plate 2 and a lower plate 3 as a substrate are connected by four support columns 4. Casters 6 are respectively disposed on the lower surfaces of the columns 4, and the support base 5 can be moved by the rotation of the casters 6.
On the other hand, on the upper surface of the upper plate 2, a first support plate 7 extending in a direction (hereinafter referred to as a main scanning direction X) orthogonal to the longitudinal direction of the upper plate 2 (hereinafter referred to as a sub-scanning direction Y). A long guide rail 8 having a substantially quadrangular prism shape is attached to the upper surface of the first support plate 7.

The guide rail 8 described above is provided with a carriage 9 that can reciprocate along the main scanning direction X. The carriage 9 includes a support portion 10 supported by the guide rail 8, a substantially rectangular parallelepiped main body portion 11, and a connecting member 12 that connects the support portion 10 and the main body portion 11.
In the region in which the carriage 9 having such a configuration moves along the main scanning direction X, the main body 11 corresponds to the operation mode of the main body 11 as shown in FIG. There are an image recording area R which is an area where an image is formed by ejecting ink and a maintenance area M where the main body 11 removes ink adhering to the nozzle.
Further, the carriage 9 moves in a direction orthogonal to the upper surface of the upper plate 2 (hereinafter referred to as a vertical direction Z) according to the recording medium P to be used. For example, when thin paper or the like is used for the recording medium P, the carriage 9 moves in a direction close to the upper surface of the upper plate 2, that is, downward, and the recording medium P is thick. When cardboard, polycarbonate, or the like is used, it moves in a direction away from the upper surface of the upper plate 2, that is, upward.

Inside the main body 11 of the carriage 9 described above, each of yellow (Y), magenta (M), cyan (C), and black (K) is directed toward the recording surface of the recording medium P as shown in FIG. A total of four recording heads 13 for discharging process color ink are mounted. The recording heads 13 are formed in a substantially rectangular parallelepiped shape, and are arranged so that the longitudinal sides of the recording heads 13 are substantially parallel to each other in the main scanning direction X.
A number of nozzles (not shown) for ejecting ink as ink droplets are arranged on the surface (hereinafter referred to as ejection surface) facing the upper plate 2 of each recording head 13. These recording heads 13 are each provided with an element that applies pressure to the ink inside, for example, by a piezo element or a heating element. When these elements are driven, ink is individually supplied from each nozzle. It is discharged as a droplet.

A horizontal plate-like second support plate 14 extends in the main scanning direction X on the downstream side of the carriage 9 in the sub-scanning direction Y. At both ends of the second support plate 14, substantially rectangular support portions 15 that support the second support plate 14 are provided on the upper plate 2, respectively.
On the second support plate 14, an ultraviolet irradiation device 16 that irradiates the recording medium P with ultraviolet rays is supported by the second support plate 14 in the image recording region R of the upper plate 2. The ultraviolet irradiation device 16 is provided with a substantially box-shaped housing 17. An ultraviolet light source (not shown) is disposed inside the casing 17, and the recording medium P is irradiated with ultraviolet rays that cure the ink ejected from the ultraviolet light source onto the upper surface of the recording medium P. It has become.

  Note that a known light source such as a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a black light, a cold cathode tube, or an LED (Light Emitting Diode) can be applied to the ultraviolet light source in the present embodiment. There is no particular limitation.

  At one end of the ultraviolet irradiation device 16 in the main scanning direction X, a cooling device 18 that blows cooling air in the direction of the upper plate 2 is provided. The cooling device 18 is provided with a rotatable cooling fan (not shown). The cooling fan is disposed so as to form a predetermined angle with respect to the second support plate 14 so as to efficiently blow cooling air to the recording medium P passing under the ultraviolet irradiation device 16.

  A recording medium scanning unit 19 is provided on the upper surface of the upper plate 2 on the opposite side of the image recording region R from the maintenance region M. As shown in FIGS. 1 and 2, the recording medium scanning unit 19 is formed in a flat plate shape that is long in the sub-scanning direction Y and fixed to the upper plate 2, and can be moved back and forth along the fixing member 20. The moving member 21 is configured. The moving member 21 is movable by a linear actuator, and the moving member 21 is reciprocated using electromagnetic force generated when the fixed member 20 is supplied with power. Further, a flat table 22 that supports the recording medium P from the lower surface is fixed to the upper surface of the moving member 21 described above so that it can reciprocate in the sub-scanning direction Y as the moving member 21 moves. It has become. This flat table 22 is a recording medium support in the present embodiment.

  The flat table 22 is provided with a lower table 23 as shown in FIG. The table lower portion 23 is provided with a barrier 24 that is divided into a portion that moves on the image region R and a portion other than that portion. Further, a barrier 25 is provided at a portion of the table lower portion 23 that is separated by the barrier 24 and moves on the image region R. The barrier 25 is divided into a peripheral portion E and a central portion C that is other than the peripheral portion E.

  On the upper part of the table lower part 23, there is provided a table upper part 26 which is flat and has the same size as the peripheral part of the table lower part 23. The table upper part 26 is provided with a penetrating suction hole 27, and the suction hole 27 arranged in the table upper part 26 is closer to the peripheral part E than the part corresponding to the upper part of the central part C of the table lower part 23. Many are arranged in the part which hits the upper part. The peripheral portion E corresponds to the peripheral portion of the recording medium P supported by the table 22, and the central portion C corresponds to the central portion of the recording medium P. In the direction perpendicular to the sub-scanning direction Y in the peripheral part E, it is desirable that a larger number of suction holes 27 are arranged than in the other peripheral parts E.

  The table lower portion 23 includes a suction device 28 that sucks a portion corresponding to the peripheral portion E of the table upper portion 26 from the back surface, and a suction device 29 that sucks a portion corresponding to the central portion C of the table upper portion 26 from the back surface. A suction pipe 30 is connected between the suction devices 28 and 29 and the table lower portion 23. The suction device 28 has a larger suction force than the suction device 29. The force with which the recording medium P is held on the table upper portion 26 is proportional to the suction force received from the back surface. For this reason, the peripheral part of the recording medium P supported by the table upper part 26 is attracted more strongly than the part other than the peripheral part and is strongly held.

  FIG. 3 shows an example in which the suction holes 27 having the same size are arranged more in the peripheral portion E of the table upper portion 26 than in the central portion C. However, the present invention is not limited to this. The suction holes may be arranged so that the density of the suction holes is higher than the density of the suction holes in the central portion C. For example, in the peripheral portion E, a configuration in which suction holes having a larger hole diameter than the central portion C or a large number of suction holes having a larger hole diameter may be used.

The ink in the present embodiment is an ultraviolet curable ink that cures when irradiated with ultraviolet rays.
Here, the ultraviolet curable ink means a radical polymerization ink containing a radical polymerizable compound as a polymerizable compound and a cationic polymerization ink containing a cationic polymerizable compound.
As the ink used in the present embodiment, both of the above-described inks can be applied. However, the cationic polymerization ink that has little or no inhibition of the polymerization reaction by oxygen is superior in functionality and versatility. In particular, it is preferable to use a cationic polymerization ink.
A hybrid ink in which radical polymerization ink and cationic polymerization ink are combined is also applicable.

  Next, the control configuration of the inkjet recording apparatus 1 in the present embodiment will be described.

  As shown in FIG. 4, the inkjet recording apparatus 1 includes a control unit 31 that controls each unit of the inkjet recording apparatus 1.

A carriage 9 is connected to the control unit 31, and reciprocation along the main scanning direction X is controlled by the control unit 31. The control unit 31 is connected with a recording head 13 that ejects ink onto the recording medium P, and controls the timing and amount of ink ejected from the recording head 13 in response to the movement of the carriage 9. Drive control is performed by the unit 31.
Furthermore, the control unit 31 is connected to an ultraviolet irradiation device 16 that irradiates ultraviolet rays toward the recording medium P, and the control unit 31 controls energization of the ultraviolet light source of the ultraviolet irradiation device 16. Yes.

The control unit 31 is connected to a recording medium scanning unit 19 that supports the recording medium P and conveys the recording medium P in the sub-scanning direction Y. The recording medium scanning unit 19 conveys the recording medium P corresponding to the movement of the carriage 9. Control is performed by the control unit 31.
In addition, suction devices 28 and 29 for sucking the recording medium P from the back surface are connected to the control unit 31, respectively. The number and size of the suction holes 27, the material, size, thickness, and the like of the recording medium P The suction force at the periphery and the center of the recording medium P is controlled in accordance with the conveyance speed of the recording medium P.

  Next, the operation of the ink jet recording apparatus 1 in the present embodiment will be described.

  When predetermined image information is sent to the ink jet recording apparatus 1, the control unit 31 drives and controls the recording medium scanning unit 19 to move the moving member 21 in the sub-scanning direction Y along the fixed member 20. The mounted table 22 is moved directly below the carriage 9.

  At this time, since the peripheral portion E of the recording medium P mounted on the table 22 is sucked more strongly than the other portion C of the recording medium P from the back surface, it is held on the table 22 with a force proportional to the suction force. Is done. For this reason, even if the table 22 moves in the sub-scanning direction Y, it is possible to prevent the peripheral portion E of the recording medium P from floating from the table 22.

When the recording medium P of the table 22 is disposed below the carriage 9, ink of a required color is ejected from the nozzles of the recording head 13 to a predetermined position of the recording medium P. The ink that has landed on the upper surface of the recording medium P is irradiated with ultraviolet rays from the ultraviolet irradiation device 16, and the ink is fixed to the recording medium P. Then, the table 22 moves in the sub-scanning direction Y with the intermittent movement of the moving member 21.
Thereafter, the same operation is repeated, a desired image is formed on the upper surface of the recording medium P, and a series of image forming operations is completed.

  As described above, according to the inkjet recording apparatus 1 of the present embodiment, the peripheral portion of the recording medium P can be supported on the table with a stronger suction force than the other portions with a simple configuration. It is possible to prevent a failure such as a jam from occurring in the image forming apparatus even if it is conveyed at high speed. Further, even if a cooling fan is provided in the vicinity of the ultraviolet irradiation device and the cooling fan blows cooling air to the recording medium, the recording medium can be prevented from being lifted or peeled off by the cooling air.

  In the present embodiment, an example in which different suction devices 28 and 29 are used for the suction hole 27 arranged in the peripheral portion E of the recording medium P and the suction hole 27 of the other portion C is shown. The present invention is not limited, and when the configuration is such that a hole having a large hole diameter is arranged in the peripheral portion E of the recording medium P or a plurality of suction holes having a large hole diameter are arranged, the recording medium P is used by using the same suction device. You may make it strengthen the suction | attraction force of the peripheral part of.

Furthermore, in the present embodiment, an example is shown in which the barrier 25 is provided inside the table lower portion 23 and the recording medium P is sucked into the peripheral portion E and the other portion C of the recording medium P in advance. However, the configuration may be such that the peripheral portion E and the other portion C of the recording medium P are separated according to the size of the recording medium P to be used.
For example, a configuration such as a table 32 that supports recording media P of A3 size and A4 size shown in FIG. 5 may be used.
Specifically, the box 33 includes a portion that moves on the image region R, a barrier 34 that divides the other portion, and a portion that moves on the image region R partitioned by the barrier 34, and an A4 size recording medium. A barrier 35 that divides the portion S larger than the peripheral portion of the portion where P is supported and a portion T other than the portion S, and a rotating portion 36 that connects the portion S and the portion T by rotation are provided. An A3 size recording medium is supported on the portion of the lid portion 37 that moves on the image area R, and an A4 size recording medium is supported on the portion of the lid portion 37 that corresponds to the upper portion of the portion S of the box portion 33. In the portion corresponding to the peripheral portion of the recording medium, more suction holes 38 pass through than the other portions. The box portion 33 is provided with a suction device 39 that sucks a portion corresponding to the portion S of the lid portion 32 from the back surface. A suction pipe 40 is connected between the suction device 39 and the box portion 33. Has been.
In such a table 32, when the A3 size recording medium P is supported, the rotating unit 36 is rotated by a motor, a solenoid or the like to connect the part S and the part T, and from the entire back surface of the A3 size recording medium. Suction is performed by a suction device 39. Further, when the A4 size recording medium P is supported on the table 32, the rotating unit 36 separates the part S and the part T, and only the part S is sucked by the suction device 39.
Moreover, although the example which controls the communication of the part S and the part T by the rotation part 36 was shown, you may make it control using not only this but a shutter, a valve, etc.

  Furthermore, a recording medium having a plurality of sizes is configured using a configuration in which the rotating unit is rotated according to the size of the recording medium used as described above and a structure in which a barrier is provided in advance as in the present embodiment. Depending on the situation, suction may be performed.

In the present embodiment, an example in which nothing other than the barrier 25 is arranged inside the table lower portion 23 is shown, but the present invention is not limited to this, and the honeycomb portion is not provided in the box portion where the barrier is not provided. A material may be used. FIG. 6 shows an example of the honeycomb material. Since this honeycomb material can use a box portion that is light and has high strength, the table can be conveyed at high speed.
Furthermore, not only a honeycomb material having a honeycomb structure but also a material having a polygonal structure such as a triangle or a quadrangle may be used.

1 is a perspective view showing an external configuration of an ink jet recording apparatus according to the present invention. FIG. 3 is an enlarged side view illustrating a configuration of a main part of the ink jet recording apparatus according to the invention. It is a perspective view which shows the structure of the cover part and box part which concern on this invention. It is a block diagram which shows the control structure of the inkjet recording device which concerns on this invention. It is a perspective view which shows another structure of the cover part and box part which concern on this invention. It is a perspective view which shows the structure inside the box part concerning this invention.

Explanation of symbols

1 Inkjet recording device 16 UV irradiation device 22, 32 Table 27, 38 Suction holes 28, 29, 39 Suction device

Claims (8)

In an image forming apparatus for forming an image on a recording medium held on a recording medium support by a suction force using a suction device,
The image forming apparatus according to claim 1, wherein a portion of the recording medium support portion that holds the peripheral portion of the recording medium is provided with more suction holes that penetrate the recording medium support portion than other portions.   The image forming apparatus according to claim 1, wherein the suction force is controlled by at least one of the number of suction holes or the hole diameter. A suction device for sucking a peripheral portion of the recording medium, and a suction device for sucking a portion other than the peripheral portion,
3. The image formation according to claim 1, wherein a suction force of a suction device that sucks a peripheral portion of the recording body is larger than a suction force of a suction device that sucks a portion other than the peripheral portion. apparatus.   The image forming apparatus according to claim 1, wherein the suction device is mounted on a portion other than the recording medium support portion.   5. The image forming apparatus according to claim 1, wherein the suction force of the peripheral portion of the recording medium corresponds to different sizes of the recording medium.   The image forming apparatus according to claim 1, wherein the recording medium support portion has a honeycomb structure. The ink is an active energy ray-curable ink that is cured by irradiation with an active energy ray,
The image forming apparatus according to claim 1, further comprising an irradiation device that irradiates the active energy ray-curable ink ejected onto the recording medium with active energy rays generated by light. .   The image forming apparatus according to claim 7, wherein the irradiation device is an ultraviolet irradiation device.

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