JP2006159499A - Inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording device which can form a stable images by irradiating a flash. <P>SOLUTION: On a flash light-emitting circuit 12 which is connected with a flash light source 11, a switching element 13 which controls a power feeding amount is provided, and the irradiation of the flash light is controlled by controlling a power feeding time, the power feeding amount and a power feeding frequency to the flash light source 11. Also, on the flash light-emitting circuit 12, a plurality of capacitors 14 in which an electricity charge amount required for the irradiation of the flash is accumulated by a power source are arranged through a connection switching means 15 which switches the connection partners of respective capacitors 14. With the connection switching means 15, a detecting means 16 which detects the electricity accumulated amount of the capacitors 14 is connected. With the flash light-emitting circuit 12, the capacitors 14 of which the electricity accumulated amounts are detected to be at a reference value or higher by the detecting means 16 are connected always through the connection switching means 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ink jet recording apparatus, and more particularly to an ink jet recording apparatus using ink that is cured by irradiation with flash light.

  In recent years, an inkjet recording apparatus has been widely used because an image can be easily and inexpensively formed as compared with a method that requires plate making such as a gravure printing method and a flexographic printing method. .

  In the field of recording an image on a product or product packaging using an inkjet recording apparatus, a material having no ink absorbability such as resin or metal is often used for the product or product packaging. When such a non-ink-absorbing material is used as a recording medium, a nozzle that discharges a photocurable ink that is cured by irradiating light such as ultraviolet rays to fix the ink on the recording medium. And a light irradiation device provided with a light source that generates light for curing the ink. After the ink ejected from the nozzle is landed on the recording medium, the light irradiation device emits light. An ink jet recording apparatus is known in which an ink is cured by irradiation to be fixed on a recording medium to form an image.

As an ink jet recording apparatus using a flash light source, a technique is disclosed in which a flash light source is provided in an ink drying unit, and the ink on the recording medium is dried by irradiating the flash (see, for example, Patent Document 1). In addition, a technique of using a flash curable ink of water-based ink is disclosed in an inkjet recording apparatus provided with a flash light source as an ink curing light source (see, for example, Patent Document 2).
JP 2000-272101A JP-T-2001-512777

  However, when a flash light source is provided in an ink jet recording apparatus and flash light is instantaneously irradiated in large quantities, the light curable ink, particularly ultraviolet curable ink, boils depending on the amount of light irradiated, or the recording medium is irradiated with ultraviolet light or Since it deteriorates due to the influence of heat, there is a problem that it is difficult to obtain a high-quality recorded image.

  Accordingly, the present invention has been made in view of the above points, and provides an ink jet recording apparatus that can perform flash irradiation optimal for the type of ink and the type of recording medium by controlling the irradiation of the flash. For the purpose.

  In order to solve the above problems, the invention described in claim 1 includes a recording head that ejects photocurable ink onto a recording medium, a flash irradiation device that irradiates a flash onto the ink ejected from the recording head, and The power storage unit of the flash irradiation device, and a control device that controls a current supply period and a power supply time to the flash irradiation device.

  According to the first aspect of the present invention, since the energization cycle and the energization time for the flash light source can be controlled, the flash irradiation amount and the irradiation time can be controlled. Further, the ink discharged onto the recording medium can be irradiated with an appropriate flash to instantaneously heat the ink to a predetermined temperature and simultaneously cure the ink.

  According to a second aspect of the present invention, in the inkjet recording apparatus according to the first aspect, a plurality of the power storage units are provided, and a switching unit that switches connection between the power storage units and the flash irradiation device is provided. To do.

  In the invention described in claim 2, since the plurality of power storage means and the switching means for switching the connection between the power storage means and the flash light source are provided, the power storage means always stored and the flash irradiation device are connected and stored simultaneously. It is possible to store power storage means that is not.

According to a third aspect of the present invention, in the ink jet recording apparatus according to the first or second aspect, the recording head is a serial type recording head that reciprocates in the main scanning direction and ejects the ink. The flash irradiation device is disposed so as to be positioned on both sides of the recording head in the main scanning direction, and irradiates the flash irradiation device on the downstream side with respect to the main scanning direction of the recording head.

  According to the third aspect of the present invention, the flash irradiation device is disposed on both sides of the serial type recording head and irradiates the flash irradiation device on the downstream side with respect to the main scanning direction of the recording head. Immediately after landing, the flash irradiation device moving on the ink is irradiated.

  According to a fourth aspect of the present invention, in the ink jet recording apparatus according to any one of the first to third aspects, the flash irradiation device is a xenon light source.

  In the invention described in claim 4, by using a xenon light source as the flash irradiation device, the light emission region of the flash irradiation can include an ultraviolet region.

  According to the first aspect of the present invention, since the flash irradiation amount and irradiation time can be controlled by controlling the energization cycle and energization time to the flash light source, the type of ink used and the type of recording medium The flash can be irradiated according to the effect.

  Furthermore, according to the first aspect of the invention, the ink can be instantaneously heated to a predetermined temperature and cured by performing appropriate flash irradiation on the ink ejected onto the recording medium. Therefore, there is an effect that an image can be reliably recorded.

  According to the second aspect of the present invention, the storage means that is always stored and the flash irradiation device can be connected and the storage means that is not stored can be stored at the same time. There is an effect that light can be emitted.

  According to the third aspect of the present invention, since only one side of the flash irradiation devices disposed on both sides of the recording head is irradiated, the flash irradiation amount can be reduced as compared with the case where the flash irradiation devices on both sides are irradiated. As a result, it is possible to efficiently use the stored energy.

  According to the invention described in claim 4, by using a xenon light source as the flash irradiation device, the light emission region of the flash irradiation can include an ultraviolet region, so that the ultraviolet curable ink is cured by flash irradiation and fixed on the recording medium. The effect which can be made is produced.

  Hereinafter, embodiments of an ink jet recording apparatus according to the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

  The ink jet recording apparatus of this embodiment is an ink jet recording apparatus using a serial type recording head. As shown in FIG. 1, the inkjet recording apparatus 1 is provided with a platen 2 that supports the recording medium P from below, and a conveying apparatus 3 that intermittently conveys the recording medium P supported by the platen 2 (FIG. 4). Reference) is provided. A bar-shaped guide rail 4 is provided above the platen 2 so as to extend in the main scanning direction A perpendicular to the conveyance direction of the recording medium P. Here, the conveyance direction of the recording medium P is defined as a sub-scanning direction B. A carriage 5 is supported on the guide rail 4, and the carriage 5 is driven by a carriage driving device 6 (see FIG. 4) so that the carriage 5 can reciprocate in the main scanning direction A, which is the longitudinal direction, along the guide rail 4. Has been.

  A plurality of process color inks such as yellow (Y), magenta (M), cyan (C), and black (K) are ejected onto the carriage 5 toward the recording surface of the recording medium P based on the image data. A recording head 7 is mounted. The ink used in the present embodiment is preferably an ultraviolet curable ink that is cured by irradiation with ultraviolet rays. In the recording head 7, a plurality of nozzles (not shown) for ejecting ink are arranged along the sub-scanning direction B with a predetermined interval.

  Further, flash irradiation devices 8 for irradiating flash are provided at both ends of the plurality of recording heads 7 mounted on the carriage. In the flash irradiation device 8, a cover member 9 formed so as to open toward the recording medium P and the platen 2 is arranged in parallel with the nozzles arranged in the recording head 7. A reflection member 10 that reflects light and irradiates the recording medium P is provided on the entire inside of the cover member 9.

Inside the cover member 9 is provided a flash light source 11 that irradiates the ink ejected from the nozzles onto the recording medium P with flash (flash), cures the ultraviolet curable ink, and fixes the ink to the recording medium. .
As the flash light source 11 in the present embodiment, it is preferable to use a xenon light source that can repeatedly irradiate a predetermined amount of flash in a short time and includes a wavelength in the ultraviolet region. FIG. 2 is an explanatory diagram showing an example of the spectrum distribution of a xenon light source as the flash light source 11. As is clear from FIG. 2, the flash light source 11 emits ultraviolet rays (wavelength range of 100 to 400 nm).

  FIG. 3 shows a schematic configuration of the flash light source 11.

  A flash light emitting circuit 12 that emits flash light is connected to a flash light source 11 that uses a xenon light source. The flash light emitting circuit 12 is provided with a switching element 13 for controlling the energization amount from the flash light emitting circuit 12 to the flash light source 11, such as an IGBT, and controls the energization time, the energization amount, and the energization number to the flash light source 11. By doing so, the irradiation of the flash light is controlled. Further, the flash light emitting circuit 12 includes a plurality of capacitors 14 as power storage means for storing a charge amount necessary for flash irradiation by a power source, and is configured by a switching circuit such as an FET so that a connection destination of each capacitor 14 is connected. They are arranged via connection switching means 15 for switching. The connection switching means 15 is connected to detection means 16 for detecting the amount of electricity stored in the capacitor 14, and the flash light emission circuit 12 is connected to the reference value (the minimum requirement for flash emission) by the detection means 16. The capacitor 14 detected as being greater than or equal to the amount of stored electricity is always connected via the connection switching means 15. In addition, a power supply 17 that stores the capacitor 14 is connected via a connection switching unit 15 to the capacitor 14 that has been detected by the detection unit 16 as having an amount of power stored equal to or less than a reference value.

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

  FIG. 4 is a block diagram showing a control configuration of the inkjet recording apparatus 1.

  As shown in FIG. 4, the inkjet recording apparatus 1 includes a control device 18 that controls the operation of each unit.

  The control device 18 is connected to an image processing unit 20 that performs image processing based on image data input via an I / F (interface) 20 from a host computer such as a personal computer connected to the outside.

  Further, the control device 18 is connected to a transport device 3, a carriage drive device 6, and a print head drive unit 21 for driving the print head 7, and drives and controls each unit based on image data.

  The controller 18 is connected to the flash light source 11 and is configured to control the irradiation operation according to the presence or absence of ink ejected from the recording head and the scanning direction of the recording head. When the ink is ejected from the recording head 7, the flash light source 11 on the downstream side with respect to the main scanning direction of the recording head 7 is irradiated, and when the ink is not ejected from the recording head 7, the flash light source 11 is not irradiated. . Here, the downstream side with respect to the main scanning direction means the rear side with respect to the main scanning direction.

  The control device 18 is connected to the connection switching means 15, the detection means 16, and the flash light emission circuit 12, and is configured such that the control device 18 controls each means. The control device 18 controls the detection means 16 to detect the amount of electricity stored in the capacitor 14. Further, the control device 18 controls the connection switching means 15 so as to always connect the capacitor 14 and the flash light emission circuit 12 that are detected that the amount of charge is equal to or more than the reference value. Is connected to the power supply 17 and the capacitor 14 is stored.

  Further, the control device 18 is connected to an input means 22 for inputting the type of recording medium used for image formation and the type of ink. When a large amount of flash light is instantaneously irradiated to a recording medium or ink landed on the recording medium, the amount of light irradiated to the recording medium or ink is not appropriate. When the ink is appropriately irradiated, the ink can be cured at the same time as the ink is instantaneously heated to a predetermined temperature. The control device 18 registers the optimum flash irradiation amount for the type of recording medium and the type of ink, and the control device 18 irradiates the optimal flash for the type of recording medium and the type of ink input. In this way, the irradiation operation can be controlled.

  FIG. 5 shows the relationship between the time when the flash is irradiated and the light emission amount. Here, the light emission time T1 is a time during which a light emission amount of 1/2 h is irradiated with respect to a peak value (maximum light emission amount) h of the light emission amount due to one energization. The energization time and the light emission amount to the flash light source 11 are in a relationship in which the light emission amount increases as the energization time increases within the energized range. Further, the light emission period equal to the energization period is T2, and the light emission rate is T1 / T2.

  The light emission period T2, the light emission rate T1 / T2, and the maximum light emission amount h in one flash emission are controlled in accordance with the type of ink used for image formation and the type of recording medium. When a recording medium sensitive to the heat and light of a flash or a cationic polymerization ink is used, a flash having a low light emission rate T1 / T2 and a small maximum light emission amount h is irradiated until a predetermined irradiation amount is reached. ing. When a recording medium or radical polymerization ink that is resistant to flash heat and light is used, a flash having a relatively high light emission rate T1 / T2 and a relatively large maximum light emission amount h reaches a predetermined irradiation amount. Until it is irradiated.

  Next, the operation in this embodiment will be described.

  When image data is input to the control device 18 via the I / F 19, the image data is converted into drive data, and the transport device 3 is driven in accordance with the drive data, so that the recording medium P is moved in the sub-scanning direction B. Transport. Thereafter, the carriage driving device 6 is driven to scan the carriage 5 along the main scanning direction A immediately above the recording medium P.

  During the scanning of the carriage 5, the control device 18 controls the recording head drive unit 21 to drive the recording head 7 based on the image data, and ejects ink from each nozzle toward the recording medium P. The ink ejected from the recording head 7 lands on the recording medium P, and then the flash light source 11 disposed on the downstream side with respect to the main scanning direction of the recording head 7 is turned on to irradiate the ink with the flash. The

At this time, the control device 18 irradiates a flash from the flash light source 11 on the downstream side with respect to the main scanning direction of the recording head 7 when ink is ejected from the recording head 7, and flashes when ink is not ejected from the recording head 7. Control to prevent irradiation.
Further, the control device 18 controls the flash light source 11 based on the type of recording medium and the type of ink input by the input unit 22, so that the optimum light emission period T2, light emission rate T1 / T2, and maximum light emission amount h are set. Illuminate the flash. The flash light source 11 irradiates a portion where ink has landed on the recording medium P until a predetermined irradiation amount is reached, and the ink on the recording medium P is quickly heated and cured to be fixed on the recording medium P.

  Thereafter, an image is recorded on the recording medium P by the ink jet recording apparatus 1 repeating the above operations.

  When the flash is emitted from the flash light source 11, the detection unit 16 detects whether or not the charged amount of each capacitor 14 is equal to or greater than a reference value. The connection switching means 15 always performs the flash irradiation by switching the connection so as to always connect the capacitor 14 and the flash light emission circuit 12 having the charged amount equal to or higher than the reference value. In addition, the connection switching unit 15 connects the capacitor 14 whose power storage amount is equal to or less than the reference value and the power source 17 so that the capacitor 14 is charged.

  As described above, in the ink jet recording apparatus 1 according to the present invention, the ink ejected onto the recording medium P is irradiated with the optimum flash to heat and cure the ink on the recording medium P under the optimum conditions. Therefore, high-quality image formation can be performed.

  In addition, by providing the plurality of capacitors 14, the connection switching means 15 and the detecting means 16, the constantly stored capacitor 14 and the flash light emitting circuit 12 are connected, so that the flash 14 is always flashed without waiting for the capacitor 14 to be stored. Irradiation can be performed.

  In this embodiment, an example in which a serial type recording head is used has been described. However, the present invention is not limited to this, and a line type recording head may be used.

  In the present embodiment, an example in which two capacitors 14 are provided has been described. However, the present invention is not limited to this, and more capacitors may be provided.

  Further, a photocurable ink in which an infrared absorbent that absorbs infrared rays and generates heat is added to a photocurable ink that is cured by irradiation with ultraviolet rays may be used. The xenon light source includes not only the wavelength in the ultraviolet region but also the wavelength in the infrared region (700 to 1000 nm). The photocurable ink irradiated with infrared rays from the xenon light source is heated and the ultraviolet ray is emitted in a state where it reaches a predetermined temperature. When irradiated, it is reliably cured on the recording medium, and a high-quality image can be formed.

1 is a schematic cross-sectional view showing a schematic configuration of an ink jet recording apparatus according to the present invention. It is explanatory drawing which shows the spectrum distribution example of the flash light source which concerns on this invention. It is the schematic which shows schematic structure of the flash light source which concerns on this invention. FIG. 2 is a block diagram illustrating a schematic control configuration of the inkjet recording apparatus according to the present invention. It is a figure which shows the relationship between time when irradiating a flash | flash, and light emission amount.

Explanation of symbols

1 Inkjet recording device 7 Recording head
DESCRIPTION OF SYMBOLS 11 Flash light source 12 Flash light emission circuit 13 Switching element 14 Capacitor 15 Connection switching means 16 Detection means 17 Power supply 18 Control apparatus

Claims (4)

A recording head for ejecting photocurable ink onto a recording medium;
A flash irradiation device for irradiating a flash to ink ejected from the recording head;
Power storage means of the flash irradiation device;
An ink jet recording apparatus comprising: a control device that controls an energization cycle and an energization time for the flash irradiation device. The inkjet recording apparatus according to claim 1, wherein
A plurality of the power storage means are provided,
An ink jet recording apparatus comprising: a switching unit that switches connection between the power storage unit and the flash irradiation device. The inkjet recording apparatus according to claim 1 or 2,
The recording head is a serial type recording head that reciprocates in the main scanning direction to discharge the ink,
The flash irradiation device is disposed so as to be positioned on both sides of the recording head in the main scanning direction, and irradiates the flash irradiation device on the downstream side with respect to the main scanning direction of the recording head. Recording device. The inkjet recording apparatus according to any one of claims 1 to 3,
An ink jet recording apparatus, wherein the flash irradiation device is a xenon light source.

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