JP2005138397A - Image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance image quality by preventing a loss in image from being caused by ink inferior in ink droplet arrival performance. <P>SOLUTION: This image recording apparatus is equipped with an inkjet recording part which is arranged on an upstream side in the direction of carrying a recording medium by a carrying part, and which records an ink image by applying light to the ink on the recording medium so as to cure the ink, after the photo-setting ink is ejected toward the recording medium. The image recording apparatus is also equipped with a toner recording part which is arranged on at least either the upstream side or downstream side in the carrying direction of the inkjet recording part, and which records a toner image by attaching toner to the recording medium. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image recording apparatus, and more particularly to an image recording apparatus using photocurable ink.

Conventionally, an ink jet recording apparatus that records an image on a transparent recording medium has been developed. In such an ink jet recording apparatus, since the recording medium is not colored, not only the actual image portion but also the background portion is printed using, for example, white ink (see, for example, Patent Document 1). .
JP 2003-182061 A

Here, a general white ink has a lower dispersibility of pigment than other color inks, and the density tends to vary, so that the landing performance is inferior to other color inks. When the landing performance is inferior, a defective portion such as a streak is generated in the back printed portion.
In addition, since titanium oxide contained in the white ink as a colorant has a specific gravity of 4 or more, which is higher than that of other colorants, there is a possibility that the titanium oxide is deposited in the ink flow path and clogs the flow path. If the ink flow path is clogged, the white image is liable to be lost, and the maintenance is troublesome.

  An object of the present invention is to prevent image loss due to ink having poor landing performance and to improve image quality.

An image recording apparatus according to the invention of claim 1
A transport unit for transporting the recording medium;
Disposed on the upstream side of the transport direction of the recording medium by the transport unit, after ejecting photocurable ink toward the recording medium, the ink on the recording medium is irradiated with light and cured. An ink jet recording unit for recording an ink image;
And a toner recording unit that is disposed on at least one of the upstream side and the downstream side in the transport direction of the ink jet recording unit and that attaches toner to a recording medium and records a toner image.

According to a second aspect of the present invention, in the image recording apparatus according to the first aspect,
The toner recording unit records white images by attaching white toner to a recording medium.

The invention described in claim 3 is the image recording apparatus according to claim 2,
The toner recording unit is arranged on the downstream side in the transport direction of the ink jet recording unit.

Invention of Claim 4 is an image recording apparatus as described in any one of Claims 1-3,
The toner recording unit is characterized in that after the recording medium is charged with a DC voltage, the toner is attached onto the recording medium with a voltage obtained by superimposing an AC voltage on the DC voltage.

  According to the first aspect of the present invention, since the ink jet recording unit and the toner recording unit are provided, the ink image and the toner image are individually recorded on the recording medium. Therefore, in the case of an ink having a landing performance that is inferior to that of other inks, the toner image is recorded using the toner of the color, thereby preventing image loss and improving the image quality.

  According to the second aspect of the invention, since the toner recording unit records a white image, the white image is recorded without discharging the white ink from the ink jet recording unit. Therefore, the white ink is unnecessary, and the image quality can be improved by preventing the loss of the white image and the clogging of the ink flow path caused by the characteristics of the white ink. Further, since the clogging of the ink flow path is prevented, maintenance work can be saved.

  According to the third aspect of the present invention, since the toner recording portion is arranged on the downstream side of the ink jet recording portion, the toner recording portion records a white image with the white toner after the image is recorded by the ink jet recording portion. be able to. In this way, if the back-printed portion is recorded with white toner, image defects such as streaks can be prevented from occurring in the back-printed portion, and the image quality can be improved.

  Here, in order to record a toner image on a recording medium, the rubbing development in which the recording medium is brought into contact with an intermediate transfer body such as a photosensitive drum on which the toner image is formed, and the toner image is recorded on the recording medium. In general, the rubbing development method is used, but when the ink image is recorded on the recording medium prior to the toner image, the toner image is recorded on the recording medium. As a result of this contact, rubbing traces are formed on the ink image and the image quality is degraded. However, if the toner recording unit charges the recording medium with a DC voltage and deposits the toner on the recording medium with a voltage obtained by superimposing the AC voltage on the DC voltage as in the invention described in claim 4, the recording is performed. Even if the medium and the intermediate transfer member are not in contact with each other, a toner image can be recorded on the recording medium, and deterioration in image quality can be suppressed.

The present embodiment will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.
First, the main configuration of the image recording apparatus of the present embodiment will be described with reference to FIG. FIG. 1 is a main configuration diagram of an image recording apparatus.

  In the image recording apparatus 1, for example, a transport unit 2 including a plurality of rollers 21 is provided to transport a transparent long recording medium P. In the transport unit 2, a support roller (not shown) that rotatably supports the recording medium P wound in a roll shape is disposed on the most upstream side in the transport direction A of the recording medium P, and is disposed on the most downstream side. Is provided with a winding roller (not shown) for winding the recording medium P on which an image is recorded. Between the support roller and the winding roller, an ink jet recording unit 3 that records an ink image on the recording medium P on the upstream side, and a toner recording unit 4 that records a toner image on the recording medium P on the downstream side. And are provided.

  The ink jet recording unit 3 records an ink image by irradiating the ink on the recording medium P with light and curing it after ejecting the photocurable ink toward the recording medium P. Yes. The ink jet recording unit 3 extends in a direction orthogonal to the transport direction A and ejects yellow (Y), magenta (M), cyan (C), and black (K) inks to the recording medium P, respectively. Four line type recording heads 31 are arranged along the conveyance direction A. A light irradiation device 32 that irradiates the ink on the recording medium P with light and cures the ink is provided downstream of the recording head 31.

  The toner recording unit 4 is configured to record a white image by attaching white toner to the recording medium P. The toner recording unit 4 includes a charging unit 5 that charges the recording medium P with a DC voltage. The charging unit 5 includes a charger 52 that charges the recording medium P with a DC voltage supplied from a DC power source 51, and the charger 52 is disposed above the recording medium P conveyed by the conveying unit 2. ing.

An exposure unit 6 that exposes the recording medium P based on white image data is disposed on the downstream side of the charging unit 5 of the toner recording unit 4 so as to face the recording medium P.
On the downstream side of the exposure unit 6 of the toner recording unit 4, an image recording unit 7 that records a white image by attaching white toner to the recording medium P is provided. The image recording unit 7 is provided with a bias power source 71 that applies a bias voltage obtained by superimposing an AC voltage on a DC voltage to white toner. When a bias voltage is applied, the white toner is scattered on the recording medium P and adheres to the exposed portion of the recording medium P (jumping development method). Here, a preferable value as the bias voltage is a value to which the jumping development method is stably applied. For example, when the reference DC voltage is 500 V, the superimposed AC voltage is 500 Hz to 1000 Hz, −2 kV to It is preferable to be within the range of 2 kV.

  A fixing unit 8 that fixes the white toner recorded on the recording medium P and records a white image is provided on the downstream side of the image recording unit 7 of the toner recording unit 4. The fixing unit 8 is provided with a pair of fixing rollers 81 for melting the white toner by heating the recording medium P and fixing the white image on the recording medium P. Here, the heating temperature by the fixing roller 81 is preferably set to 120 ° C. to 130 ° C. while melting the white toner but not disturbing the ink image on the recording medium P.

  Even if the image recording speeds of the ink jet recording unit 3 and the toner recording unit 4 are different between the ink jet recording unit 3 and the toner recording unit 4, the conveyance of the recording medium P is stabilized by loosening the recording medium P. A dancer roller 9 that can be moved up and down is provided.

Further, the image recording apparatus 1 is provided with a control device that controls each drive unit. The control device includes an interface, a recording circuit, a CPU, and the like, and controls various devices connected to the interface according to a control program and control data written in the recording circuit.
The drive sources of the transport unit 2, the inkjet recording unit 3, the toner recording unit 4, and the dancer roller 9 are electrically connected to the interface. In addition to the above, each drive unit of the image recording apparatus 1 is connected to this interface.
The CPU expands a program designated from various programs stored in the recording circuit to a work area in the recording circuit, and executes various processes according to the program in accordance with input signals from each unit. It has become.

Next, the operation of the image recording apparatus 1 of the present embodiment will be described.
The control device controls the transport unit 2 so that the recording medium P is transported continuously at the image recording timing. As the recording medium P is conveyed, the control device controls the recording head 31 so that ink is ejected from each recording head 31, and the light irradiation device 32 emits light toward the recording medium P. Then, the light irradiation device 32 is controlled to record an ink image on the recording medium P. This ink image is a real image portion.

Thereafter, the control device controls the dancer roller 9 to loosen the recording medium P so that the recording medium P is stably conveyed to the toner recording unit 4.
When the ink image recorded by the ink jet recording unit 3 enters the toner recording unit 4, the control device controls the charging unit 5 so that the recording medium P is charged with a DC voltage by the charger 52.

Thereafter, the control device controls the exposure unit 6 to expose the surface of the recording medium P based on the white image data, and then controls the bias power source 64 to apply the bias voltage to the white toner to scatter the white toner. The white image is recorded on the recording medium P.
Then, the control device controls the fixing unit 8 to melt the white toner on the recording medium P and fix the white image on the recording medium P. In this way, the white image is printed on the actual image portion made of the ink image, and the background portion made of the white image is recorded.

As described above, according to the image recording apparatus 1 of the present embodiment, since the ink image and the white image are individually recorded on the recording medium P, the white ink whose landing performance is inferior to other inks is used. Even if it is not used, a white image can be recorded. As a result, image loss can be prevented, and the image can be improved in image quality.
As described above, when the white ink is not necessary, it is possible to prevent the loss of the white image caused by the characteristics of the white ink and the clogging of the ink flow path, and to improve the image quality. Further, since the clogging of the ink flow path is prevented, maintenance work can be saved.
Further, after the image is recorded by the ink jet recording unit 3, the toner recording unit 4 records a white image with the white toner. High image quality can be achieved.

  Here, the rubbing development method is generally used for recording the toner image. However, when the rubbing development method is used, the ink image is recorded on the recording medium P before the toner image. The contact when the toner image is recorded on the recording medium P forms a rubbing trace on the ink image and degrades the image quality. However, as described above, if the toner recording unit 4 charges the recording medium P with a DC voltage and then attaches white toner on the recording medium P with a voltage obtained by superimposing the AC voltage on the DC voltage, the recording medium A white image can be recorded on the recording medium P without bringing an intermediate transfer member or the like into contact with P, and deterioration in image quality can be suppressed.

Of course, the present invention is not limited to this embodiment and can be modified as appropriate.
For example, in the present embodiment, the configuration in which the light irradiation device 32 is disposed on the downstream side of the plurality of recording heads 31 has been exemplified. However, for example, the light irradiation device 32 is disposed immediately downstream of each recording head 31. If so, it is possible to prevent the inks from being mixed on the recording medium P.
Further, in the present embodiment, the case where the line type recording head 31 is used in the inkjet recording unit 3 has been described as an example, but a serial type recording head may be used instead of the line type. Absent.

Further, in the present embodiment, only the case where the toner recording unit 4 records a white image as a background portion with white toner is illustrated, but the actual image portion may be recorded with white toner. In such a case, the toner recording unit may be disposed on at least one of the upstream side and the downstream side in the transport direction of the ink jet recording unit.
Further, the toner recording unit may record a toner image using a toner of a color other than white. In such a case, it is preferable from the viewpoint of improving the image quality to use a toner of an ink color having poor landing performance. .

It is explanatory drawing showing the main structures of the image recording apparatus in this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Conveying part 3 Inkjet recording part 4 Toner recording part 31 Recording head 32 Light irradiation apparatus A Conveying direction P Recording medium

Claims (4)

A transport unit for transporting the recording medium;
Disposed on the upstream side of the transport direction of the recording medium by the transport unit, after ejecting photocurable ink toward the recording medium, the ink on the recording medium is irradiated with light and cured. An ink jet recording unit for recording an ink image;
An image recording apparatus comprising: a toner recording unit disposed on at least one of an upstream side and a downstream side in the transport direction of the ink jet recording unit to attach a toner to a recording medium and record a toner image. The image recording apparatus according to claim 1,
The toner recording section records a white image by attaching white toner to a recording medium. The image recording apparatus according to claim 2,
The image recording apparatus, wherein the toner recording unit is disposed downstream of the ink jet recording unit in the transport direction. In the image recording device according to any one of claims 1 to 3,
The toner recording unit, after charging the recording medium with a DC voltage, causes the toner to adhere to the recording medium with a voltage obtained by superimposing an AC voltage on the DC voltage.

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