JP2010149400A - Device and method for inkjet recording - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for inkjet recording which securely cures and fixes ink according to a recording state of ultraviolet curable ink. <P>SOLUTION: The device 1 for inkjet recording is provided with: a recording section 1 which moves an inkjet recording head 10 for ejecting ultraviolet curable ink, in main scanning directions (X1 and X2), thereby recording on a sheet-like recording medium S; a recording conveyance section 2 for conveying the recording medium S in a sub scanning direction (Y); a fixing section 3 which moves an ultraviolet light irradiation section 30 in the main scanning directions (X1 and X2), the ultraviolet light irradiation section 30 irradiating the ultraviolet curable ink with ultraviolet light thereby curing the ultraviolet curable ink, and which fixes the ultraviolet curable ink to the recording medium S as a result; and a fixing conveyance section 4 disposed adjacent to the downstream side of the recording conveyance section 2 in its conveying direction (sub scanning direction (Y)), which conveys the recording medium S in the sub scanning direction (Y). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ink jet recording apparatus that records on a recording medium using ultraviolet curable ink, and fixes the recorded ultraviolet curable ink on a recording medium by irradiating the cured ultraviolet light with curing.

  Inkjet recording devices are currently used in various fields because they can be lightweight and downsized and have less vibration and noise during recording, and the recording media that are to be printed are also diversifying. . Conventionally, paper has been mostly used as a recording medium, but in recent years, application to recording media other than paper has been attempted. As a recording method therefor, an ink jet recording method using an ultraviolet curable ink has been proposed.

  Ultraviolet curable ink is cured by irradiating with ultraviolet rays, so that the ink ejected from the ink jet recording head and adhered to the surface of the recording medium is irradiated with ultraviolet rays to penetrate into the recording medium or on the recording medium. It is possible to cure the ink promptly before bleeding occurs. Therefore, high quality not only on ink-absorbing recording media such as paper, fabric, and wood, but also on non-ink-absorbing recording media such as leather, glass, metal, ceramics, and films without forming an ink receiving layer. Images can be formed.

  As a method of irradiating ultraviolet rays for curing the ultraviolet curable ink recorded on the recording medium, for example, in Patent Document 1, the recording medium moves in the main scanning direction by the recording head and records on the recording medium while recording in the sub scanning direction. The point that ultraviolet rays are irradiated to the recorded recording medium while moving the ultraviolet light source in the main scanning direction is described. Patent Document 2 describes that a recording head for discharging an ultraviolet curable ink for recording and an ultraviolet irradiation device for irradiating ultraviolet rays are mounted on a carriage to perform a recording operation. Further, in Patent Document 3, an inkjet head that discharges and records ultraviolet curable ink and ultraviolet irradiation means are mounted on a carriage to perform a recording operation in the main scanning direction and convey the recording medium in the sub scanning direction. This document describes that another ultraviolet irradiation means is moved in the main scanning direction on the downstream side in the conveying direction to irradiate the recording medium with ultraviolet rays.

Further, in Patent Document 4, when performing the fixing process by heating and pressurizing the ink recorded on the recording medium, the recording medium transport unit during the recording operation by the recording head and the recording medium during the fixing process by the fixing unit It is described that the transporting operation is performed by switching the transport means.
JP 2004-167793 A Japanese Patent Laying-Open No. 2005-313445 JP 2003-191593 A JP 2003-182173 A

  In the above-described patent document, as in Patent Document 1, when ultraviolet irradiation is performed on the downstream side in the transport direction from the recording head, it is necessary to perform ultraviolet irradiation according to the transport speed of the recording medium in the recording operation by the recording head. When the recorded recording area or the ink adhesion amount changes, it is difficult to change the ultraviolet irradiation area and the irradiation amount correspondingly. Further, if the irradiation amount is set so that the ink is reliably cured and fixed even if such a change in the recording state occurs, the recording medium may be overheated by ultraviolet rays.

  It is necessary to irradiate ultraviolet rays according to the main scanning speed and the conveyance amount of the recording medium in the recording operation by the recording head. However, if the conditions related to ink curing such as the amount of deposited ink change, It is difficult to change the dose. Also, in order to set the irradiation amount so that the ink is cured and fixed reliably even if such a change in the recording state occurs, it is necessary to change the main scanning speed and the recording medium conveyance amount in the recording operation by the recording head. However, changing the recording operation causes a decrease in recording quality and recording speed.

  In addition, as in Patent Document 2, when the ultraviolet irradiation device is moved together with the recording head to cure the ink immediately after recording, it is necessary to set the irradiation amount according to the recording speed of the recording head and the amount of ejected ink. In order to cure the ink reliably, the irradiation amount must be set large, and the ultraviolet irradiation device must be enlarged accordingly. When the size of the ultraviolet irradiation device is increased, there is a problem that the size of the carriage and the driving force of the moving mechanism need to be correspondingly increased, which increases the cost burden.

  Even when the carriage-mounted irradiation means and the irradiation means on the downstream side in the transport direction are provided as in Patent Document 3, as described in Patent Documents 1 and 2, the recording speed and transport speed of the recording operation are adhered to the recording medium. It is still difficult to irradiate with ultraviolet rays so that the ink is reliably cured in accordance with the amount of ink.

  Patent Document 4 describes the point of switching between the recording operation and the fixing operation of a general ink jet recording apparatus, but does not mention the fixing operation with respect to the ultraviolet curable ink.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ink jet recording apparatus capable of reliably curing and fixing ink according to the recording state of ultraviolet curable ink.

  An ink jet recording apparatus according to the present invention includes a recording unit that moves an ink jet recording head that discharges ultraviolet curable ink in a main scanning direction to record on a recording medium, and a recording transport unit that transports the recording medium in a sub scanning direction. The ultraviolet ray curable ink is moved by moving the ultraviolet ray irradiating unit for irradiating the ultraviolet ray curable ink by irradiating the ultraviolet ray curable ink in the main scanning direction. A fixing unit that fixes the recording medium; a fixing conveyance unit that is disposed adjacent to a downstream side of the recording conveyance unit in a conveyance direction and conveys the recording medium in a sub-scanning direction; and the fixing unit and the fixing conveyance unit And a fixing control unit that performs a fixing operation. Further, the fixing control unit controls the conveyance of the fixing conveyance unit based on the length of the irradiation range of the ultraviolet irradiation unit in the sub-scanning direction and the number of times of irradiation to the same location. Further, the fixing unit has an ultraviolet irradiation unit for a head that moves together with the inkjet recording head and cures the ultraviolet curing ink immediately after recording so as to suppress bleeding.

  The ink jet recording method according to the present invention performs a recording operation on a recording medium by moving an ink jet recording head that discharges ultraviolet curable ink in the main scanning direction and transporting the recording medium in the sub scanning direction by a recording transport unit. An ultraviolet irradiation unit that carries the recorded recording medium into a fixing conveyance unit arranged adjacent to the downstream side in the conveyance direction of the recording conveyance unit and cures the ultraviolet curable ink by irradiating ultraviolet rays in the main scanning direction. A fixing operation for fixing the ultraviolet curable ink to the recording medium is performed by moving the recording medium in the sub-scanning direction by the fixing conveyance unit. Further, the recording medium is transported based on the length of the irradiation range of the ultraviolet irradiation unit in the sub-scanning direction and the number of times of irradiation to the same location.

  Since the present invention has the above-described configuration, it is possible to independently control the recording operation on the recording medium and the fixing operation of the recording medium, and the conveyance control of the recording medium in the recording operation and the fixing operation can be performed. Even if they are different, both operations can be performed in parallel. Therefore, it is possible to increase the production efficiency as compared with the case where the recording medium is transported in the recording operation and the fixing operation by a single transport unit.

  In addition, since the fixing conveyance unit is arranged adjacent to the downstream side in the sub-scanning direction of the recording conveyance unit, the recorded recording medium can be directly carried into the fixing conveyance unit, and the recording medium conveyance operation can be efficiently performed. Can be done.

  Since the fixing operation can be performed independently, it is possible to irradiate the ultraviolet irradiation portion according to the recording state of the recording medium, and the ultraviolet curing recorded while minimizing the influence of the ultraviolet rays on the recording medium. The mold ink can be reliably cured. Also, if the recording medium is transported based on the length of the irradiation range of the ultraviolet irradiation unit in the sub-scanning direction and the number of times of irradiation to the same location, the curing is performed according to the amount of the ultraviolet curable ink attached to the recording medium. Therefore, it is possible to finely adjust the irradiation amount of ultraviolet rays necessary for fixing, and a fixing operation without irradiation unevenness can be performed. Therefore, the amount of irradiation is small and curing is insufficient, or excessive irradiation of ultraviolet rays to prevent damage such as overheating to the recording medium.

  In addition, the UV curable ink immediately after recording is temporarily cured by an ultraviolet irradiation unit for the head that moves together with the ink jet recording head to prevent ink bleeding, and the temporarily cured ink is applied to the recording medium by the ultraviolet irradiation unit in the fixing unit. If the ink is completely cured by irradiation, good image recording with less ink bleeding can be performed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiments described below are preferable specific examples for carrying out the present invention, and thus various technical limitations are made. However, the present invention is particularly limited in the following description. Unless otherwise specified, the present invention is not limited to these forms.

  FIG. 1 is a perspective view showing a schematic configuration of the ink jet recording apparatus. The ink jet recording apparatus 1 includes a recording unit 1 that records on a sheet-like recording medium S by moving an ink jet recording head 10 that discharges ultraviolet curable ink in the main scanning direction (X1, X2), and the recording medium S in the sub scanning direction. The recording / carrying unit 2 for conveying in (Y) and the ultraviolet irradiation unit 30 for irradiating and curing the ultraviolet curable ink with ultraviolet rays are moved in the main scanning direction (X1, X2) to fix the ultraviolet curable ink to the recording medium S. A fixing unit 3 to be moved, and a fixing conveyance unit 4 which is arranged adjacent to the downstream side in the conveyance direction (sub-scanning direction (Y)) of the recording conveyance unit 2 and conveys the recording medium S in the sub-scanning direction (Y). I have.

  The recording unit 1 has an inkjet recording head 10 having a plurality of head units arranged in the main scanning direction mounted on a carriage 11 and supports the carriage 11 on a guide rail 12 so as to be slidable in the main scanning direction. Further, a timing belt 13 is stretched around the drive pulley and the driven pulley along the guide rail 12, and the timing belt 13 is moved in the main scanning direction by rotationally driving the drive pulley by the carriage motor 14. Yes. The carriage 11 is attached to the timing belt 13, and the carriage 11 is moved in the main scanning direction by the movement of the timing belt 13.

  The inkjet recording head 10 is configured such that ultraviolet curable ink is supplied from an ink supply mechanism (not shown) and ink is ejected from nozzles formed on the lower surface. As such an ink jet recording head, a known one can be used. A recording signal is transmitted to the ink jet recording head 10 via the flexible cable 15, and the ink jet recording head 10 is selectively driven based on the recording signal, and ultraviolet curable ink is ejected and adheres to the recording medium. .

  The recording transport unit 2 includes an endless transport belt 20 that transports the recording medium S, a pair of transport rollers 21 and 22 that stretch the transport belt 20 and move it in the sub-scanning direction, and a transport motor that rotationally drives the transport roller 21. 23.

  The recording medium S carried into the recording / conveying unit 2 from a carrying-in mechanism (not shown) is placed on the conveying belt 20. Temporary fixing means such as a detachable adhesive tape is provided on the upper surface of the conveyor belt 20, and the recording medium S placed on the conveyor belt 20 is fixed by the temporary fixing means and moved toward the recording unit 1. It is conveyed in the scanning direction.

  When the leading end of the recording medium S reaches a position facing the ink jet recording head 10, the ink jet recording head 10 ejects ultraviolet curable ink according to the recording signal while moving in the main scanning direction, and records on the recording medium. When the recording of the predetermined scanning line is completed, the conveying belt 20 conveys the predetermined scanning line in the sub-scanning direction, and discharges the ultraviolet curable ink while moving the inkjet recording head 10 with respect to the next scanning line. To do. Thus, the recording operation with the ultraviolet curable ink can be performed on the entire recording medium S by repeating the recording in the main scanning direction of the inkjet recording head 10 and the conveyance in the sub-scanning direction of the conveyance belt 20.

  The fixing unit 3 has an ultraviolet irradiation unit 30 attached to a carriage 31 and supports the carriage 31 on a guide rail 32 so as to be slidable in the main scanning direction. A timing belt 33 is stretched around the drive pulley and the driven pulley along the guide rail 32, and the timing belt 33 moves in the main scanning direction by driving the drive pulley by the carriage motor 34. Yes. The carriage 31 is attached to a timing belt 33, and the carriage 31 is moved in the main scanning direction by the movement of the timing belt 33. An irradiation control signal is transmitted to the ultraviolet irradiation unit 30 via the flexible cable 35, and the ultraviolet irradiation unit 30 irradiates the ultraviolet curable ink recorded on the recording medium S with ultraviolet rays based on the irradiation control signal.

  The distance between the inkjet recording head 10 and the ultraviolet irradiation unit 30 is set so that the influence of the ultraviolet irradiation unit 30 does not reach the inkjet recording head 10. If the interval between the two is set to be equal to or longer than the length of the recording medium S in the sub-scanning direction, the recording medium recorded by the inkjet recording head 10 is conveyed as it is and the recording medium is irradiated by the ultraviolet irradiation unit 30. Can do.

  Further, when recording on a long recording medium such as a film, fabric, synthetic leather, etc., in order to absorb the difference in processing speed between the recording unit 1 and the fixing unit 3, the recording conveying unit 2 and the fixing conveying unit. 4, the recording medium is controlled so that the recording medium is slacked downward, and the recording unit 1 and the fixing unit 3 are controlled so that the sagging amount falls within a certain range while detecting the sagging amount. Specifically, when the processing speed of the fixing unit 3 is faster than that of the recording unit 1, the fixing process is interrupted when it is detected that the amount of sag is decreasing and becomes smaller than a predetermined lower limit value. . Thereafter, when the amount of sag increases and exceeds a predetermined upper limit value, the fixing process may be resumed. Conversely, when the processing speed of the fixing unit 3 is slower than the recording unit 1, the recording process is interrupted when the amount of sag increases and exceeds the upper limit value, and then the amount of sag decreases and exceeds the lower limit value. In such a case, the recording process may be resumed.

  FIG. 2 is a schematic cross-sectional view of the ultraviolet irradiation unit 30 viewed from the sub-scanning direction. The ultraviolet irradiation unit 30 has an ultraviolet lamp 301 mounted inside a housing 300 having a rectangular shape in plan view and opened downward. A condensing reflector 302 is provided so as to surround the upper part of the ultraviolet lamp 301, and a pair of shutters 303 for shielding ultraviolet rays are provided below the ultraviolet lamp 301. In addition, a heat ray cut filter 304 is attached to the opening below the housing 300 in order to prevent the recording medium S and the transport roller 40 from being overheated during ultraviolet irradiation.

The ultraviolet light emitted from the ultraviolet lamp 301 is condensed by the reflector 302 as shown by a thin line in the figure, and is applied to the recording medium S with an intensity of 0.5 to 4 W / cm ² . The emitted ultraviolet light is condensed by a reflector 302 onto a strip-shaped irradiation region having a narrow width in the main scanning direction and a predetermined length in the sub scanning direction.

  The shutter 303 is opened and closed by a shutter operation mechanism (not shown) from an open state indicated by a solid line in the drawing to a closed state indicated by a dotted line. While the recording medium S does not reach, the shutter 303 is set in a closed state to prevent overheating due to ultraviolet irradiation of the conveying roller 40 and the like, and when the recording medium S recorded with ultraviolet curable ink arrives, the shutter 303 is opened. In this state, the recording medium S is irradiated with ultraviolet rays. In this way, by irradiating the recording medium S with ultraviolet rays by opening and closing the shutter 303, it is not necessary to turn on the ultraviolet ray 301 every time the ultraviolet ray lamp 301 is radiated. It is also possible to extend the life.

  The fixing conveyance unit 4 includes a roller conveyor in which a plurality of conveyance rollers 40 are arranged in the sub-scanning direction, and is rotated by a conveyance motor 41 so as to convey the recording medium S placed on the upper surface of the conveyance roller 40. It has become. The transport roller 40 may be a metal roller that is durable against the irradiated ultraviolet rays. Each transport roller 40 is connected by a connection mechanism (not shown) and is rotationally driven in synchronization by a transport motor 41.

  The conveyance roller 40 is disposed adjacent to the conveyance belt 20 on the downstream side in the conveyance direction of the recording medium S, and the recording medium S carried out by the conveyance belt 20 is carried onto the conveyance roller 40 as it is. Is set.

  FIG. 3 is a schematic block diagram relating to the control of the ink jet recording apparatus. The apparatus control unit 100 includes a recording control unit 101 and a fixing control unit 102, and performs a recording operation and a fixing operation based on a recording signal transmitted from the external device 200.

  The recording control unit 101 includes a head driving circuit 110 that drives the inkjet recording head 10 based on a recording signal, a carriage motor driving circuit 111 that drives a carriage motor 14 that moves the carriage 11, and a conveyance motor 23 that conveys and moves the conveyance belt 20. The conveyance motor drive circuit 112 for driving the ink is controlled, and the ultraviolet curable ink is ejected from the inkjet recording head 10 to perform the recording operation on the recording medium.

  The fixing control unit 102 includes a lamp irradiation circuit 120 that irradiates an ultraviolet lamp 301 of the ultraviolet irradiation unit 30, a shutter drive circuit 121 that opens and closes a shutter 303 of the ultraviolet irradiation unit 30, and a carriage that drives a carriage motor 34 that moves the carriage 31. The motor driving circuit 122 and the conveying motor driving circuit 123 for driving the conveying motor 41 for rotating the conveying roller 40 are controlled, and the fixing operation is performed by irradiating the ultraviolet curable ink recorded on the recording medium with ultraviolet rays.

  Fixing control is performed based on the adhesion amount of the ultraviolet curable ink recorded on the recording medium and the durability of the recording medium against ultraviolet irradiation.

  The adhesion amount of the ultraviolet curable ink is determined based on the recording signal for driving the ink jet recording head 10. Then, the ultraviolet irradiation amount necessary for curing is calculated on the basis of the determined adhesion amount, and the irradiation is performed. In this case, the fixing operation must be performed in consideration of the durability of the recording medium against the ultraviolet irradiation. .

  Although it is conceivable to change the ultraviolet intensity of the ultraviolet irradiation section according to the durability of the recording medium, even if the intensity of the ultraviolet light is weakened, if the irradiation is continued until the predetermined irradiation amount is reached, the recording medium is heated or the like. Will have a negative effect.

  In order to avoid the influence of heating accompanying such irradiation, the predetermined irradiation dose can be irradiated with the influence of heating minimized by irradiating the same place intermittently while reciprocating the ultraviolet irradiation section. .

An experiment in which ultraviolet rays are intermittently irradiated will be described below. In this experiment, the same illuminance (W / cm) was obtained while reciprocating the ultraviolet irradiation section with a scanning line of 2 m with respect to the surface of a recording medium (sheet body made of synthetic leather having a length of 0.47 m, a width of 1 m, and a thickness of 1 mm). ² ), the maximum surface temperature of the recording medium was measured when the total irradiation dose (J / cm ² ) of each irradiation pattern was the same. Here, the irradiation dose (J / cm ² ) is expressed by the following equation.
Irradiation amount (J / cm ² ) = Illuminance (W / cm ² ) × Time (seconds)

Experiments were performed on the following three patterns as irradiation patterns. The amount of irradiation with ultraviolet rays increases as the moving speed of the ultraviolet irradiation section increases, the irradiation time at the same location becomes shorter and the amount of irradiation in one scan decreases. Thus, the total irradiation amount in each irradiation pattern is made the same.
Irradiation pattern 1 (moving speed: 35.7 mm / second, number of irradiation times: once)
Irradiation pattern 2 (moving speed: 250 mm / second, number of irradiation times: 7 times)
Irradiation pattern 3 (moving speed: 500 mm / second, number of times of irradiation: 14 times)
When the temperature of the surface of the recording medium after irradiation was measured, the maximum temperature of the surface was as follows.
Irradiation pattern 1; 82 ° C
Irradiation pattern 2: 58 ° C
Irradiation pattern 3; 48 ° C
Therefore, by shortening the irradiation time of the ultraviolet rays and increasing the number of irradiations by that amount, it is possible to reliably cure the ultraviolet curable ink by irradiating a necessary irradiation amount while suppressing the influence of heating by the ultraviolet irradiation.

The fixing transport unit is transport-controlled at a transport speed such that a necessary irradiation amount is irradiated onto the recording medium by moving and controlling the ultraviolet irradiation unit in the main scanning direction with a predetermined irradiation pattern. In the case of continuous conveyance, the conveyance speed V1 is set based on the following formula. Here, L is the length of the irradiation range of the ultraviolet irradiation unit in the sub-scanning direction, T is the movement time of the ultraviolet irradiation unit per movement in the main scanning direction, and M is the number of irradiations of the ultraviolet irradiation unit.
V1 = L / (T × M)
The movement time T is calculated based on the movement control of the carriage on which the ultraviolet irradiation unit is mounted, and includes an acceleration period at the start of carriage movement, a deceleration period at the end of movement, a constant speed period between the acceleration period and the deceleration period, It is the total time of the stop period until the movement starts in the opposite direction after the movement is completed. Actually, a detection sensor for detecting the passage of the carriage may be provided in the movement path of the carriage, and the movement time T may be set based on a detection signal from the detection sensor.

  For the number of irradiations M, the irradiation amount necessary for curing the ultraviolet curable ink to be used in advance is measured by an experiment or the like, and the above-mentioned irradiation pattern experiment is performed based on the measured irradiation amount, and the optimum ultraviolet irradiation for the recording medium. The moving speed of the part and the number of irradiations are obtained. Then, the number of irradiations may be adjusted in accordance with the increase or decrease of the actually recorded ink adhesion amount with reference to the obtained number of irradiations.

  In the case of intermittent conveyance in which movement control and conveyance control are alternately performed by conveying the recording medium once after moving the carriage once instead of continuously conveying in the fixing conveyance unit, the conveyance amount per time May be set to L / M.

  Alternatively, the recording area may be determined based on a recording signal for driving the inkjet recording head 10, and the movement of the carriage 31 and the transport roller 40 may be controlled in accordance with the determined recording area. By performing the fixing operation with the movement controlled in this way, it is possible to reduce the irradiation of the ultraviolet ray to the region where the ultraviolet curable ink is not attached. Further, by controlling the shutter 303 so as to be closed in correspondence with the determined recording area, it is possible to prevent the ultraviolet ray from being irradiated to the area where the ultraviolet curable ink is not attached.

  When performing a fixing operation on a heat-sensitive recording medium, the carriage 31 and the conveyance roller 40 are controlled to move in accordance with the length of the recording medium in the scanning direction to prevent deformation and discoloration. Good.

  A detection sensor 50 for detecting the presence or absence of the recording medium S is disposed between the recording conveyance unit 2 and the fixing conveyance unit 4, and a detection signal from the detection sensor 50 is transmitted to the recording medium end detection circuit 150 for recording. It is determined whether the leading edge or trailing edge of the medium S has been detected. For example, when the detection signal of the detection sensor 50 changes from the state without the recording medium S to the state where the recording medium S is present, it is determined that the leading edge has been detected, and when the state changes from the state where the recording medium S is present to the state where the recording medium S does not exist, the rear end May be determined as having been detected. The leading edge detection signal or the trailing edge detection signal thus determined is transmitted to the recording control unit 101 and the fixing control unit 102.

  FIG. 4 is a flow relating to the recording process and the fixing process, and FIG. 5 is an operation explanatory diagram thereof. In the recording process, first, it is checked whether or not a recording signal is input (S100), and when a recording signal is input, the recording medium S is carried into the conveying belt 20 as shown in FIG. (S101).

  Next, the loaded recording medium S is transported in the sub-scanning direction by the transport belt 20, and when the arrival sensor (not shown) detects that the leading edge of the recording medium S has arrived at the recording start position of the ink jet recording head 10. The recording process is started (S102). In the recording process, the inkjet recording head 10 is driven by the recording signal to control the movement in the main scanning direction while ejecting ink to record an image of a predetermined scanning line on the recording medium, and then control the conveyance of the recording medium in the sub-scanning direction. Then, the next scan line is recorded.

  When the recording process is performed and the recording medium S is conveyed in the sub-scanning direction, the leading edge of the recording medium S is detected by the detection sensor 50 as shown in FIG. In the fixing process, it is checked whether or not the leading edge of the recording medium S has been detected (S200). When the leading edge of the recording medium S is detected, the clutch of the transport roller 40 is disengaged and set to a freely rotatable state (S201). ).

  Further, as the recording process is performed, the recording medium S is conveyed in the sub-scanning direction and supported by the conveying roller 40 from the front end. At this time, since the conveyance roller 40 rotates freely, the recording medium S smoothly transfers to the conveyance roller 40 as shown in FIG.

  When the recording process is completed (S103), an end signal is transmitted to the fixing control unit, and the clutch of the conveying roller 40 is connected (S202). Then, a clutch connection signal is transmitted to the recording control unit, and the recording control unit and the fixing control unit perform conveyance control in synchronization (S104, S203). By synchronous conveyance, as shown in FIG. 5D, the recording medium S can be transferred to the conveyance roller 40 at high speed. Then, the conveyance control of the recording medium S is performed by the conveyance roller 40 after the synchronous conveyance, and when the arrival sensor (not shown) detects that the leading edge of the recording medium S has reached the fixing start position, the fixing process is started. (S204). In the fixing process, the ultraviolet irradiation unit 30 is controlled to move in the main scanning direction, and the recording medium is transported and controlled in the sub-scanning direction while the ink is cured in a predetermined irradiation pattern, and a predetermined range of ink is sequentially fixed on the recording medium. Go.

  When the fixing process is performed and the recording medium S is conveyed in the sub-scanning direction, the rear end of the recording medium S is detected by the detection sensor 50 as shown in FIG. In the recording process, it is checked whether the trailing edge of the recording medium S is detected (S105). When the trailing edge of the recording medium S is detected, the recorded recording medium S is separated from the conveying belt 20 and completely conveyed. Since the process has shifted to step S100, the process returns to step S100 to perform the next recording process.

  Further, when the fixing process is performed and the fixing process of the entire recording medium S is completed (S205), the fixing-processed recording medium S is carried out (S206). At that time, as shown in FIG. 5F, the next recording medium S is carried in parallel with the fixing process and the recording process is performed.

  As described above, by controlling the fixing process independently of the recording process, the fixing process can be reliably performed in accordance with the recording state of the ultraviolet curable ink, and the fixing process is performed in parallel with the recording process. The speed can be improved.

  FIG. 6 is a schematic configuration diagram regarding a modified example of the fixing unit 3. In this example, a pair of head ultraviolet irradiation units 37 and 38 are attached to both sides of the inkjet recording head 10 in the main scanning direction, and the head ultraviolet irradiation units 37 and 38 move together with the inkjet recording head 10. Yes.

  The ultraviolet irradiation units 37 and 38 for the head are smaller and have a lower output than the ultraviolet irradiation unit 30, and irradiate the ultraviolet curable ink immediately after being ejected from the inkjet recording head 10 and attached to the recording medium with ultraviolet rays. Temporarily cure to the extent that it does not bleed. Then, the temporarily cured ultraviolet curable ink is completely cured by the ultraviolet irradiation unit 30, and high-quality recording processing without pixel bleeding can be performed even when the amount of ink attached is large.

  In the present invention, when performing inkjet recording using an ultraviolet curable ink, the influence of ultraviolet rays on the recording medium can be suppressed. Therefore, as a recording medium, paper, film, leather, fabric, plastic, metal, glass, ceramic, cement It can be widely used for recording media of various materials such as ceramics and porcelain.

1 is a perspective view illustrating a schematic configuration of an ink jet recording apparatus. It is the schematic sectional drawing seen from the subscanning direction regarding an ultraviolet irradiation part. FIG. 2 is a schematic block configuration diagram relating to control of an inkjet recording apparatus. It is a flow regarding a recording process and a fixing process. FIG. 10 is an operation explanatory diagram regarding a recording process and a fixing process. It is a schematic block diagram regarding the modification of a fixing | fixed part.

Explanation of symbols

1 Recording section
10 Inkjet recording head 2 Recording transport section
20 Conveyor belt 3 Fusing unit
30 UV irradiation unit 4 Fixing and conveying unit
40 Transport roller

Claims (5)

  A recording unit that moves an inkjet recording head that discharges ultraviolet curable ink in a main scanning direction to record on a recording medium, a recording conveying unit that conveys the recording medium in a sub-scanning direction, the recording unit, and the recording conveying unit A recording control unit that controls the recording operation, a fixing unit that fixes the ultraviolet curable ink to the recording medium by moving an ultraviolet irradiation unit that irradiates and cures the ultraviolet curable ink with ultraviolet rays in the main scanning direction, and A fixing conveyance unit that is arranged adjacent to the downstream side of the recording conveyance unit in the conveyance direction and conveys the recording medium in the sub-scanning direction; and a fixing unit that performs a fixing operation by controlling the fixing unit and the fixing conveyance unit An ink jet recording apparatus comprising: a control unit.   2. The inkjet according to claim 1, wherein the fixing control unit controls the conveyance of the fixing conveyance unit based on the length of the irradiation range of the ultraviolet irradiation unit in the sub-scanning direction and the number of times of irradiation to the same location. Recording device.   The inkjet recording according to claim 1, wherein the fixing unit includes an ultraviolet irradiation unit for a head that moves together with the inkjet recording head and cures the ultraviolet curing ink immediately after recording so as to suppress bleeding. apparatus.   The inkjet recording head that discharges the ultraviolet curable ink is moved in the main scanning direction, and the recording medium is conveyed in the sub-scanning direction by the recording conveyance unit to perform a recording operation on the recording medium, and the recorded recording medium is recorded in the recording medium. An ultraviolet irradiation unit that is carried into a fixing conveyance unit disposed adjacent to the downstream side in the conveyance direction of the conveyance unit and that is cured by irradiating the ultraviolet curable ink with ultraviolet rays is moved in the main scanning direction, and the fixing conveyance unit An ink jet recording method comprising: performing a fixing operation for fixing an ultraviolet curable ink to the recording medium by conveying the recording medium in a sub-scanning direction.   The inkjet recording method according to claim 4, wherein the recording medium is transported based on a length in a sub-scanning direction of an irradiation range of the ultraviolet irradiation unit and the number of times of irradiation to the same location.

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