JP2012020482A - Inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the effect of disconnection of a light emitting element.SOLUTION: In an inkjet recording device 10 including a recording head 20 ejecting ink of an ultraviolet curing type, a conveying device 30 conveying a recording medium P facing an ink ejection surface of the recording head, and an ultraviolet ray irradiation device 40 provided downstream of the recording head relative to the conveying direction in which the conveying device conveys the recording medium, the ultraviolet ray irradiation device forms a plurality of groups in which a plurality of light emitting elements arranged along a column in a direction different from the conveying direction F are connected in series on a plane parallel to the recording medium conveyed by the conveying device, and includes an energization part 50 for performing energization to each group.

Description

  The present invention relates to an ink jet recording apparatus using ultraviolet curable ink.

Conventionally, in an inkjet recording apparatus using ultraviolet curable ink, after ejecting ink droplets from an inkjet head provided above a recording medium, an LED of an ultraviolet light source is irradiated to cure the ink and fix it. Yes.
And in order to equalize the amount of irradiation of ultraviolet rays, a unit was formed by arranging LEDs at the apexes of equilateral triangles arranged on the plane without gaps, and ultraviolet irradiation was performed by the units. Further, in the prior art, in order to suppress the influence of the light amount change due to the temperature change of the LED, the temperature of the LED is detected, and control for increasing or decreasing the electric energy supplied to the LED is performed based on the detected temperature (for example, , See Patent Document 1).

  In addition, in the ink jet recording apparatus in which the LEDs are unitized as described above, each LED is further divided into a plurality of groups, and a pulse circuit for supplying a pulse current to the LEDs of each group is provided, and current pulses to be supplied to each group A conventional technique has been devised to increase the lifetime of the LED and make the irradiation light uniform by appropriately adjusting the frequency and phase of the LED (for example, see Patent Document 2).

JP 2005-153193 A JP 2006-231795 A

When a plurality of LEDs are arranged in a two-dimensional shape in the direction perpendicular to the conveyance direction and the conveyance direction to achieve uniform UV irradiation on the plane of the recording medium, each LED has a failure such as disconnection due to its lifetime, for example. When this occurs, the amount of UV irradiation is reduced only in that portion, and there is a problem that UV curing and fixing cannot be achieved partially.
Therefore, in each of the above prior arts, it is possible to make the irradiation amount of each LED uniform and extend the life, but if the individual LED is disconnected due to a failure or a lifespan, it is no longer irradiated. It was impossible to avoid unevenness in the amount of light, and it was impossible to cope with a decrease in recording image quality and occurrence of recording failure.

  An object of the present invention is to provide an ink jet recording apparatus capable of effectively preventing an adverse effect on image formation by preliminary ejection ink due to failure or failure of individual light sources when a plurality of irradiation light sources are used. To do.

  According to a first aspect of the present invention, there is provided a recording head that discharges ultraviolet curable ink, a transport device that transports a recording medium to a position facing the ink ejection surface of the recording head, and the transport device transports the recording medium. In the inkjet recording apparatus, the ultraviolet irradiation apparatus includes an ultraviolet irradiation apparatus that is provided on the downstream side of the recording head in the conveyance direction and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. A plurality of groups in which a plurality of light emitting elements arranged in a direction different from the transport direction are connected in series on a plane parallel to the recording medium transported by the transport device and energizing each of the groups It comprises a part.

  According to a second aspect of the present invention, there is provided a recording head that discharges ultraviolet curable ink, a transport device that transports a recording medium to a position facing the ink ejection surface of the recording head, and the transport device transports the recording medium. In the inkjet recording apparatus, the ultraviolet irradiation apparatus includes an ultraviolet irradiation apparatus that is provided on the downstream side of the recording head in the conveyance direction and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. A group in which a plurality of light emitting elements arranged in a direction different from the transport direction and obliquely intersecting the transport direction on a plane parallel to the recording medium transported by the transport device are connected in series And a plurality of energization sections for energizing each of the groups.

  According to a third aspect of the present invention, there is provided a recording head that discharges ultraviolet curable ink, a transport device that transports a recording medium to a position facing the ink ejection surface of the recording head, and the transport device transports the recording medium. In the inkjet recording apparatus, the ultraviolet irradiation apparatus includes an ultraviolet irradiation apparatus that is provided on the downstream side of the recording head in the conveyance direction and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. A plurality of groups in which a plurality of light emitting elements arranged in a direction different from the transport direction and orthogonal to the transport direction on a plane parallel to the recording medium transported by the transport device are connected in series It is characterized by having an energization part which energizes each of the group while forming.

  The invention according to claim 4 has the same configuration as that of the invention according to claim 2, and two units each holding the plurality of light emitting elements are arranged side by side in the transport direction of the recording medium, and the recording medium A movable mechanism that enables movement of at least one unit along a direction orthogonal to the transport direction of the plurality of light emitting elements arranged in one row among the plurality of light emitting elements connected in series. The energizing unit is controlled so that the same triangular area emits light in opposite directions with respect to each unit, and the triangular area is formed on the width of the recording medium or the recording surface of the recording medium. And a light emission control unit that controls the movable mechanism so as to form a parallelogram region that matches the width of the recorded image.

  The invention described in claim 5 has the same configuration as that of the invention described in claim 4, and width detection for detecting the width of the conveyed recording medium or the width of the recording image formed on the recording surface of the recording medium. The light emission control unit includes the energization unit and the movable mechanism so that the detected width of the recording medium or the width of the area where the recording is performed is a parallelogram area. A first light emission control unit to be controlled is provided.

  The invention described in claim 6 has the same configuration as that of the invention described in claim 2 or 3, and two sets of units each holding the plurality of light emitting elements in a rectangular plane are arranged in the transport direction of the recording medium. A movable mechanism that is arranged and capable of moving at least one unit along a direction orthogonal to the conveyance direction of the recording medium, and the width of the recording medium or the width of the recording image formed on the recording surface of the recording medium And a light emission control unit that controls the movable mechanism to shift the units in the width direction so that the widths match when the unit is wider than the single unit. .

  The invention according to claim 7 has the same configuration as that of the invention according to any one of claims 1 to 6, and the individual light emitting elements connected to each row of the plurality of light emitting elements connected in series. A second light emission control unit that controls the amount of irradiation light based on the number information is provided.

  The invention according to claim 8 has the same configuration as that of the invention according to any one of claims 1 to 7, and disconnection is detected for each column of the plurality of light emitting elements connected in series. Provided with a detection unit, for the energization unit that can be energized for each column of the plurality of light emitting elements connected in series, other than the row of the light emitting elements in which disconnection is detected by the disconnection detection unit, A third light emission control unit that performs control so that the amount of irradiation light increases with respect to the row of light emitting elements located upstream and downstream in the transport direction with respect to the row of light emitting elements in which the disconnection is detected; It is characterized by.

  The invention according to claim 9 is provided with the same configuration as that of the invention according to any one of claims 1 to 7, and disconnection is detected for each column of the plurality of light emitting elements connected in series. A detection unit is provided, and when the disconnection detection unit detects a disconnection in any one of the light emitting element columns, the detection unit includes a transport control unit that controls the transport device so that the speed is lower than when no disconnection is detected. It is characterized by that.

  The invention described in claim 10 has the same configuration as that of the invention described in any one of claims 1 to 9, and disconnection is detected for each column of the plurality of light emitting elements connected in series. A detection unit is provided, and when the disconnection is detected by the disconnection detection unit, a notification unit that warns of disconnection is provided.

  The invention described in claim 11 has the same configuration as that of the invention described in claim 10, and the disconnection warning is performed only at the first recording per day.

  The invention described in claim 12 has the same configuration as that of the invention described in any one of claims 1 to 11, and the energization unit performs energization control to each light emitting element by PWM control. It is characterized by.

In the present invention, since a plurality of groups in which a plurality of light emitting elements arranged in a direction different from the conveyance direction of the recording medium are connected in series is formed, and an energization unit for energizing each group is provided, When a wire or a light emitting element is disconnected, it is possible to compensate for a decrease in the amount of irradiated light by turning off the light due to the disconnection in the light emitting elements arranged in the transport direction of the recording medium configured as different groups. The situation that occurs can be avoided, and relatively good recording can be performed even when a disconnection occurs.
Furthermore, the arrangement direction of the groups of light emitting elements may be a direction that obliquely intersects or is orthogonal to the transport direction.

  Further, in the case where a plurality of groups in which a plurality of light emitting elements are arranged in a direction obliquely intersecting the transport direction is formed, two units emit light in a triangular area in opposite directions, and one side of each other matches. By adopting a configuration in which the movable mechanism is controlled as described above, the parallelogram region can be caused to emit light. In such a configuration, the width of the parallelogram area can be made variable by adjusting the number of rows forming each triangular area, and the width of the parallelogram can be set on the recording medium. By controlling the energization unit so as to coincide with the width or the width of the recorded image, it is possible to make the UV irradiation amount uniform in the width direction, avoid unnecessary lighting of the light emitting elements, and save power. It becomes possible.

  Further, when the width of the recording medium or the width of the recording image is detected by the width detecting means when emitting light in the parallelogram area and irradiating with ultraviolet rays, the width of the recording medium or the width of the recording image is automatically set. It is more preferable from the standpoint that it is possible to obtain the target, emit light within an appropriate range, and perform ultraviolet irradiation.

  Further, when the two units are configured to be shifted in the width direction, the irradiation range can be widened, and thus when performing ultraviolet irradiation on a recording medium or recording image wider than the unit alone. It is more preferable from the viewpoint that it is possible to cope with various recording media or recording ranges by performing the widening movement of the unit so as to match the width.

  Further, when the second light emission control unit that controls the amount of irradiation light based on the information on the number of individual light emitting elements connected to each column of the plurality of light emitting elements connected in series is provided, Even when the number of individual light emitting elements is different, it is possible to make the irradiation amount uniform for each light emitting element. For example, it is possible to make the irradiation amount uniform in the direction orthogonal to the transport direction.

  Further, when a plurality of light emitting elements connected in series due to disconnection are extinguished, the recording is conveyed in the direction intersecting the light emitting element rows when the irradiation amount of the light emitting elements in the upstream or downstream row is increased. The medium is more preferable from the viewpoint that the light emitting elements in the adjacent row can compensate for the decrease in the irradiation amount of ultraviolet rays due to the disconnected light emitting elements, and that good recording can be performed even if the disconnection occurs.

  In addition, when the disconnection detection unit detects a disconnection in any of the light emitting element rows, it is disconnected and extinguished when the transport device is controlled to be slower than when no disconnection is detected. It is more preferable from the viewpoint that it becomes possible to avoid shortage of the irradiation amount of ultraviolet rays due to the above.

  Furthermore, when a plurality of light emitting elements connected in series due to disconnection are extinguished, the disconnection is detected by the disconnection detection unit, and when the warning is given by the notification means, the disconnection can be quickly recognized and fixed. This is more preferable from the viewpoint that it is possible to avoid continuing recording with defects occurring.

  Furthermore, if the system is configured to warn only at the first recording per day, it avoids repeated or continuous warnings when repair work such as disconnection or replacement of light emitting elements is not performed immediately. It is more preferable from the viewpoint that it is possible to obtain a degree of freedom in appropriately selecting the timing of the return operation.

  Furthermore, when the power supply control to each light emitting element is performed by PWM control, the light emitting element can be turned on with a small current, and the light emission amount can be controlled without changing the current value itself. From the viewpoint of becoming, it is more preferable.

1 is a schematic diagram illustrating an outline of an ink jet recording apparatus according to a first embodiment. 1 is a block diagram illustrating an overall configuration of an ink jet recording apparatus. It is a top view of a LED array. The wiring for energizing each ultraviolet LED held in the LED array is shown. It is a block diagram which shows the control system centering on the electricity supply part which energizes with respect to one group of ultraviolet LED. It is a flowchart which shows a 1st disconnection process. It is a display example of a warning display screen. 8A and 8B are operation explanatory views of the ultraviolet irradiation device in the second disconnection process. It is a flowchart which shows a 2nd disconnection process. It is a flowchart which shows the example which added the process which stops electricity supply to the group which disconnected in the 2nd disconnection process of FIG. It is a top view of the ultraviolet irradiation device of a second embodiment. FIG. 12A is a plan view of the ultraviolet irradiation apparatus according to the third embodiment, and FIG. 12B is a plan view of the recording medium conveyed. It is a top view of the ultraviolet irradiation device of a fourth embodiment. It is a flowchart of the irradiation control with respect to the ultraviolet irradiation device which a control part performs. It is operation | movement explanatory drawing of irradiation control when the width | variety of a recording medium is wide. FIG. 16A is a plan view showing a state at the time of disconnection detection of the ultraviolet irradiation apparatus of the application example, and FIG. 16B is a plan view showing a state in which irradiation control for the disconnection is performed. It is a flowchart of irradiation control of an application example.

(First embodiment)
Hereinafter, an inkjet recording apparatus will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the overall configuration of the inkjet recording apparatus 10, and FIG. 2 is a block diagram. Further, the X-axis direction in FIG. 1 indicates the horizontal direction, and the Z-axis direction indicates the vertical vertical direction.
As shown in FIG. 1, the ink jet recording apparatus 10 is a line type ink jet printer, and ejects ink from a recording head 20 to a recording medium P to form an image on the recording medium P. Here, the line-type ink jet printer refers to a state in which the recording head 20 that ejects ink is fixed and the recording medium P is transported in the predetermined transport direction F by the transport device 30 and transported below the recording head 20. The recording head 20 discharges ink toward the recording medium P to form an image on the recording medium P.

  The inkjet recording apparatus 10 includes a recording head 20 that performs recording by discharging ultraviolet curable ink to the recording medium P, and a medium supply unit 11 that feeds unused recording medium P and supplies the recording head 20 to the recording head 20. A medium collection unit 12 that collects the recording medium P that has been recorded by the recording head 20, a conveyance device 30 that conveys the recording medium P from the medium supply unit 11 to the medium collection unit 12, and a conveyance path of the recording medium P. A trigger sensor 13, an encoder 16 that detects the conveyance speed of the recording medium P, an ultraviolet irradiation device 40 that cures the ultraviolet curable ink applied to the recording medium P by the recording head 20, and the above-described configurations. A control unit 70 that performs operation control, a support frame 14 that supports each of the above components, and a PC (Personal Computer) 17 connected to the control unit 70 are provided.

As shown in FIG. 1, the medium supply unit 11 is a starting point in the conveyance path of the recording medium P, holds a roll of unused recording medium P, and feeds the recording medium P from the roll by the feeding motor 11a. ing.
Further, the medium recovery unit 12 is an end point in the conveyance path of the recording medium P, and collects the recording medium P by winding it with a winding roll of the recording medium P that has been recorded by the recording head 20. For this reason, the medium recovery unit 12 includes a winding motor 12a that rotationally drives the winding roll.

The transport device 30 transports the recording medium P from the medium supply unit 11 to the medium recovery unit 12 through the platen 15 serving as a recording position provided on the upper portion of the support frame 14.
The transport device 30 includes a plurality of transport rollers 31 arranged at various locations along the transport path from the medium supply unit 11 through the platen 15 to the medium recovery unit 12, and the recording medium P is formed by the transport rollers 31. While applying a predetermined tension so as not to sag, a transport motor (not shown) that drives each transport roller 31 so as to pass through the platen 15 at a constant transport speed is driven.

  Further, any of the transport rollers 31 is equipped with the encoder 16 described above, and the transport speed of the recording medium P is detected by the control unit 70 from the rotational speed of the transport rollers 31. Thereby, the control unit 70 controls the transport device 30 so as to maintain a predetermined target transport speed, and drives the feeding motor 11a and the take-up motor 12a at appropriate speeds so that no slack is generated in the recording medium P. Transport.

  The support frame 14 accommodates the above-described transport device 30, the medium supply unit 11, and the medium recovery unit 12 inside, and a smooth platen 15 that is horizontally attached to the upper portion thereof, and a vertically lower side with respect to the platen 15. The recording head 20 that is directed to eject ink and the ultraviolet irradiation device 40 that is disposed on the downstream side in the transport direction with respect to the recording head 20 are supported.

(Recording head)
A plurality of (for example, four) recording heads 20 are prepared for each color to be used, and in each of these, the discharge nozzles are directed vertically downward. The recording heads 20 for each color are provided side by side along the transport direction F (parallel to the X-axis direction) of the recording medium P so that the recording heads 20 are substantially equally spaced. The recording head 20 is arranged in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side along the conveyance direction F of the recording medium P. The arrangement order of the recording heads 20 can be changed as appropriate. Moreover, the color and the number of colors of the ink used are not limited to this.

Each recording head 20 has a nozzle in a direction perpendicular to the conveyance direction F of the recording medium P (the width direction of the recording medium P conveyed on the platen 15, strictly speaking, the horizontal direction and the direction orthogonal to the conveyance direction. In the following description, this direction is referred to as the Y-axis direction), and the recording is performed by ejecting ink toward the recording medium P conveyed by the conveying device 30. A color image can be formed on the medium P.
The length of each recording head 20 in the Y-axis direction corresponds to the maximum width of the recording medium P targeted by the inkjet recording apparatus 10, and the nozzle surface has a width exceeding the maximum recording medium P (image formation). This is a full-line type head in which a plurality of nozzles for ink discharge are arranged over the entire width of the range.
In this embodiment, the full-line type head is described. However, the present invention is not limited to the full-line type head, and the recording medium is transported in a predetermined direction by a transport device and ejects ink. However, the present invention is also applicable to a scan type head that reciprocates in the direction perpendicular to the conveyance direction of the recording medium along the surface of the recording medium to form an image on the recording medium.

In addition, each recording head 20 includes a drive control unit 21 that provides a piezoelectric element in a pressure chamber communicating with the ejection nozzle and applies a pulse voltage, and controls the driving of the transported recording medium P at an appropriate timing. By controlling the unit 21 to drive, image formation corresponding to the recording image data is performed on the recording medium P. The drive timing of the drive control unit 21 is determined based on the sensor output of the trigger sensor 13 that optically detects the recording medium P arranged upstream in the transport direction.
In addition, the method for ejecting ink is not limited to the above-described one. For example, an electro-mechanical conversion method (for example, single cavity type, double cavity type, bender type, piston type, shear mode type) , Shared wall type, etc.), electro-thermal conversion method (for example, thermal ink jet type, bubble jet (registered trademark) type, etc.), electrostatic attraction method (for example, electrolytic control type, slit jet type, etc.) and discharge method (for example, Any type of discharge recording head may be used.
The trigger sensor 13 described above is provided on the upstream side in the transport direction of each recording head 20 so that the recording timing of each recording head 20 is controlled according to the position of the recording medium P detected by the trigger sensor 13. It has become.

Each of the recording heads 20 is provided with an ink supply unit 22 including an ink tank that stores ink and a pressurizing unit that supplies ink to the recording head 20 from the ink tank. Ink is supplied into each head 20.
In the inkjet recording apparatus 10, the ink supply unit 22 supplies ultraviolet curable ink to the recording head. Such an ultraviolet curable ink is an ink containing a component (a UV curable component such as a monomer, oligomer, low molecular weight homopolymer or copolymer) that is cured (polymerized) by application of UV energy and a polymerization initiator. When light is received, the polymerization starts, the viscosity increases with the progress of the polymerization, and eventually cures. Here, as the ultraviolet curable ink used in the present embodiment, a radical polymerization ink containing a radical polymerization compound as a polymerizable monomer or a photopolymerization initiator, a cationic polymerization ink containing a cation polymerization compound, or the like is used. Preferably used. The radical polymerization ink does not start the polymerization reaction unless the amount of ultraviolet light applied to the ink exceeds a certain threshold, but has a characteristic that the radical polymerization reaction is easily inhibited by oxygen in the air. Unlike radical polymerization inks, cationic polymerization inks do not inhibit the polymerization reaction by oxygen in the air, but have the property that when the ink is irradiated with ultraviolet light, the polymerization reaction proceeds by the amount of the irradiated ultraviolet light. .

(UV irradiation device)
The ultraviolet irradiation device 40 will be described with reference to FIGS.
The ultraviolet irradiation device 40 includes an ultraviolet LED (Light Emitting Diode) 41 as a plurality of light emitting elements, an LED array 42 as an LED unit holding the ultraviolet LEDs 41 arranged in a horizontal plane, and the ultraviolet LEDs 41 of the LED array 42. It is mainly comprised from the electricity supply part 50 which supplies electricity with respect to.
FIG. 3 is a plan view of the LED array 42. As shown in the figure, the LED array 42 holds a plurality of ultraviolet LEDs 41 side by side on the same plane, and the plane holding each LED 41 is parallel to the XY plane and is close to and opposed to the upper surface of the platen 15. It is supported by the support frame 14.

In the LED array 42, the ultraviolet LEDs 41 are arranged on intersections of lattices of equal intervals parallel to the X-axis direction and the Y-axis direction on a square plane parallel to the XY plane. That is, the ultraviolet LEDs 41 are two-dimensionally arranged along the XY plane, and are arranged in parallel in both the X-axis direction and the Y-axis direction. Moreover, as shown in FIG. 3, each ultraviolet LED 41 is in any of the oblique directions (lower left oblique direction and lower right oblique direction in FIG. 3) that form an angle of 45 degrees with respect to both the X axis direction and the Y axis direction. Are also lined up in parallel.
The LED array 42 is provided with 13 × 13 = 169 ultraviolet LEDs 41, but the number of individuals may be increased or decreased.
Further, the width in the X-axis direction and the width in the Y-axis direction of the region where each ultraviolet LED 41 is attached in the LED array 42 are the same, and both of them match the printable width of the recording head 20. That is, as shown in FIG. 3, the UV curable ink is cured on the recording medium P having the maximum width, which is somewhat wider than the maximum width of the recording medium P usable in the inkjet recording apparatus 10. It is possible.

  FIG. 4 shows wiring for energizing each ultraviolet LED 41 held in the LED array 42. As illustrated, the ultraviolet LEDs 41 are arranged along a direction inclined at 45 degrees with respect to the X-axis direction and the Y-axis direction (lower left oblique direction in FIG. 3), and a plurality of ultraviolet LEDs 41 arranged in the left oblique lower direction are arranged. The ultraviolet LED 41 is connected in series, and wiring is performed so that energization is performed from the A side (A1 to A25) to the B side (B1 to B25). A plurality of ultraviolet LEDs 41 connected in series in a line along the lower left diagonal direction constitute one group, and in the case of 13 × 13 = 169 ultraviolet LEDs 41 described above, 25 groups are formed. It has become. Moreover, among the groups, the group located on the diagonal line has the largest number of individuals of the ultraviolet LED 41, and the group having fewer individuals of the ultraviolet LED 41 is formed as the distance from the group increases (the upper left corner and the lower right corner). Only the ultraviolet LED 41 in FIG. 1 is a single unit, but this is also referred to as a group for convenience).

FIG. 5 is a configuration diagram showing a control system centering on the energization unit 50 that energizes one group of the ultraviolet LEDs 41.
As shown in the figure, the energization section 50 has a constant cycle from the A side to the B side with respect to one or more M LEDs (13 in the example of FIG. 4, but the number is not limited) connected in series. A PWM control unit 51 that repeatedly energizes ON and OFF, an error amplifier 54A that controls energization to the PWM control unit 51, and a disconnection detection unit 52 that includes a comparator 54B for detecting disconnection of the ultraviolet LED 41. I have. A resistor 53 for preventing reverse withstand voltage is connected in parallel with the ultraviolet LED 41 connected in series. The energization unit 50 is provided for each group of ultraviolet LEDs 41.
The control part 70 sets the magnitude | size of the electric current supplied with respect to ultraviolet LED41. Thereby, the PWM control unit 51 can appropriately control the light amount of each ultraviolet LED 41 through the switch means 55. When the ultraviolet LED 41 connected in series is disconnected, the voltage rises and is detected by the comparator 54B. Thereby, the disconnection detection signal of the disconnection detection unit 52 is output to the control unit 70. Similarly, when the ultraviolet LED 41 is disconnected, the current does not flow through the resistor Rs, so that the disconnection detection signal A is output to the control unit 70. For this reason, the control part 70 judges a disconnection based on one of the disconnection detection signals.

(Control part)
As shown in FIG. 2, the control unit 70 is connected to the PC 17 via an interface (for example, USB [Universal Serial Bus]). The PC 17 inputs image data to be recorded on the recording medium P to the control unit 70, and displays a notification screen on the display device 17 a provided in the PC 17 in accordance with a notification command issued from the control unit 70.
On the other hand, the control unit 70 controls the conveyance device 30 and the drive control unit 21 of the recording head 20 according to the image data input from the PC 17 to form an image on the recording medium P. Is well known and will not be described.

  Since the number of individuals of the ultraviolet LEDs 41 may be different for each group of ultraviolet LEDs 41 connected in series, the control unit 70 sets the magnitude of the current to be energized according to the number of individuals of the ultraviolet LEDs 41. Thus, the amount of each ultraviolet irradiation of the ultraviolet LED 41 is made uniform. The information on the number of the individual UV LEDs 41 is set from the PC 17 connected via the interface or set in the control unit 70 in advance. Thereby, the control unit 70 functions as a second light emission control unit.

Next, the process at the time of detecting the occurrence of disconnection of the ultraviolet irradiation device 40 performed by the control unit 70 will be described.
As described above, the ultraviolet irradiation device 40 is provided with the disconnection detecting unit 52 for each group of the ultraviolet LEDs 41, and can detect the disconnection individually.
The control unit 70 uses the disconnection detection unit 52 to perform a first disconnection process that notifies when a disconnection is detected and a second disconnection process that suppresses a decrease in the amount of ultraviolet irradiation when a disconnection is detected. It is said.

(First disconnection process)
FIG. 6 is a flowchart showing the first disconnection process.
As shown in the figure, when printing is started (step S1), the control unit 70 energizes each group of the ultraviolet LED 41 through each PWM control circuit 51 at a predetermined cycle and duty ratio, thereby The LED 41 is turned on (step S3).

At this time, the control unit 70 determines whether a disconnection is detected for the disconnection detection unit 52 provided for each group of the ultraviolet LEDs 41 (step S5).
When a disconnection occurs in any one of the ultraviolet LEDs 41, no current flows to all the ultraviolet LEDs 41 in the same group, so that the disconnection detection unit 52 provided in the group detects the occurrence of the disconnection and notifies the control unit 70. Output.

When the disconnection is detected, the control unit 70 determines whether or not the current printing is the first printing today (step S7).
That is, the control unit 70 includes a built-in clock and can always acquire the current time. The control unit 7 incorporates a counter that is reset when the date changes in conjunction with the built-in clock, and counts the number of executions of recording on the recording medium P. When it is determined whether or not the printing is the first printing today, it is determined whether or not the recording number counter is “1”.

If it is the first printing today, a warning display command is input to the PC 17 (step S9). FIG. 7 is a display example of a warning display screen. The PC 17 receives the warning display command and executes the display of the warning display screen of FIG.
The image data of the display screen shown in this figure may be transmitted from the control unit 70 to the PC 17 or stored on the PC 17 side.

On the other hand, in step S5, when no disconnection is detected from any of the disconnection detection units 52, the first disconnection process ends without performing the notification process.
Further, in step S7, even when a disconnection from any one of the disconnection detection units 52 is detected, but the first printing is not performed, the first disconnection process is ended without performing the notification process.

(Second disconnection process)
8A and 8B are explanatory diagrams of the operation of the ultraviolet irradiation device in the second disconnection process, and FIG. 9 is a flowchart showing the second disconnection process.
As shown in the figure, when printing is started (step S11), the control unit 70 energizes each group of the ultraviolet LEDs 41 through each PWM control circuit 51 at a predetermined cycle and duty ratio, and outputs each ultraviolet ray. The LED 41 is turned on (step S13).

At this time, the control unit 70 determines whether or not a disconnection is detected for the disconnection detection unit 52 provided for each group of the ultraviolet LEDs 41 (step S5).
If any one of the UV LEDs 41 is disconnected, no current flows to all the UV LEDs 41 connected in series, and as shown in FIG. 8A, all the UV LEDs 41 connected in series are turned off. (The UV LED 41 that is turned off is marked with x in the figure). Then, the disconnection in the group is detected by the disconnection detection unit 52 and input to the control unit 70.

  Then, when a disconnection is detected, the control unit 70 identifies in which group the disconnection has occurred (step S17). For example, in each of the plurality of disconnection detection units 52, the signal type of the detection signal input to the control unit 70 is unique (for example, the detection signal is a voltage signal and the voltage value is changed for each group), or The control unit 70 specifies in which group of the ultraviolet LEDs 41 the disconnection has occurred, for example, by receiving detection signals from the plurality of disconnection detection units 52 at different input ports.

Next, when the group of the ultraviolet LED 41 that has caused the disconnection is specified, the control unit 70 further specifies a group adjacent to the group (step S19).
For example, the control unit 70 stores arrangement data for specifying the order in which the groups of the ultraviolet LEDs 41 are arranged, and specifies a group adjacent to the group in which the disconnection has occurred by referring to the data. Then, the PWM control unit 51 of the adjacent group is controlled to increase the duty ratio, and the light emission amount of the ultraviolet LED 41 belonging to the adjacent group is increased. That is, as shown in FIG. 8B, by increasing the light emission amount for the two groups of ultraviolet LED 41 adjacent to both sides of the group of the ultraviolet LED 41 that is extinguished due to the disconnection, the irradiation amount decreased due to the disconnection is reduced. I make up for it. Thus, the control unit 70 functions as a third light emission control unit.

  In step S15, if no disconnection is detected from any of the disconnection detectors 52, the second disconnection process is terminated, and normal ultraviolet irradiation is performed as it is.

  In addition, although the case where the control which raises the light emission amount was performed for two groups adjacent on both sides of the group of the ultraviolet LED 41 which caused the disconnection was illustrated, the light emission amount may be increased only on one side group instead of the both sides.

  In other words, it is desirable to set the current set value during normal light emission in consideration of the case where the light emission amount is increased, and the current set value for the PWM control unit 51 when increasing the light emission amount is set as normal light emission. It is desirable to determine the current setting value at the time. In addition, since the number of ultraviolet LEDs 41 connected in series differs from group to group, the current setting value when performing control to increase the amount of light emission may be determined individually for each group.

  Moreover, although the case where the arrangement | positioning data of each group was utilized when specifying other adjacent groups with respect to the group of ultraviolet LED41 which produced the disconnection was illustrated, it is not restricted to this, For example, it is disconnected in each group In this case, it is possible to prepare data in a table format that determines in advance which group the light emission amount is to be increased, and perform control for specifying the group that increases the light emission amount with reference to the table.

  As shown in FIG. 10, when the group of the ultraviolet LEDs 41 causing the disconnection is specified by the process of step S17, the process of stopping energization to the PWM control unit 51 of the group (step S18). May be added. Even if the current does not flow to the ultraviolet LED 41 due to the disconnection, the PWM control unit 51 performs the process of generating the pulse signal. Therefore, as in step S18, the PWM control unit 51 is turned off to save power. be able to.

  In the second disconnection process, control is performed to increase the light emission amount of the group adjacent to the group that has generated the disconnection at the time of disconnection detection. Instead, the transport speed of the transport device 30 is set to the normal speed at the time of disconnection detection. You may perform control as a conveyance control part which switches to low speed rather than conveyance speed. In this case, the amount of light emission is reduced by turning off the ultraviolet LED 41 due to disconnection, but the recording medium P passes by that amount, so that the amount of ultraviolet rays received during the passage is sufficiently secured, and the ultraviolet curable ink is sufficient. Curing can be realized.

(Effect of the first embodiment)
As described above, since the ultraviolet irradiation device 40 of the ink jet recording apparatus 10 performs energization by connecting a plurality of grouped ultraviolet LEDs 41 in series, the energization unit 50 may be provided for each group. The manufacturing cost of the apparatus can be reduced as compared with the case where the energization unit is provided.
Further, since the ultraviolet LEDs 41 are connected in series, the value of the current flowing from the energization unit 50 can be reduced as compared with the case where they are connected in parallel, and a highly specific circuit that handles a high current can be dispensed with.

Furthermore, the ultraviolet irradiation device 40 forms a plurality of groups of the plurality of ultraviolet LEDs 41 arranged along a row that is oblique with respect to the conveyance direction F of the recording medium P, and each ultraviolet ray is grouped by the energizing unit 50 for each group. The LED 41 is connected in series and energized.
For this reason, the entire group is extinguished due to the occurrence of the disconnection, but the row of the ultraviolet LEDs 41 forming the group is not parallel to the transport direction of the recording medium P, and thus is locally in the width direction of the recording medium. In particular, it is possible to avoid insufficient curing of the ink due to a reduction in the amount of ultraviolet irradiation, and it is possible to reduce the influence of disconnection and perform stable ultraviolet irradiation.

Further, since the control unit 70 performs the first disconnection process in the inkjet recording apparatus 10, the operator can quickly recognize the disconnection when any of the ultraviolet LEDs 41 of the ultraviolet irradiation device 40 is disconnected. It becomes.
Further, in the first disconnection process, since a warning display for notifying the disconnection is performed only at the first recording of the day, it is possible to avoid a complicated situation in which the warning display is performed at each printing.

Moreover, since the control part 70 performs the 2nd disconnection process, the inkjet recording device 10 can avoid generation | occurrence | production of insufficient irradiation amount of an ultraviolet-ray, even if a disconnection arises about any ultraviolet LED41, and ultraviolet curing Occurrence of insufficient curing of the mold ink can be prevented.
In addition, since replacement of parts and repair work are not required, it is particularly effective when printing on the recording medium P is required prior to repair or the like.

  In addition, although the group of several ultraviolet LED41 connected in series illustrated the case where all arranged in the direction inclined 45 degree | times with respect to the X-axis direction and the Y-axis direction, it is not limited to this direction. That is, the group of ultraviolet LEDs 41 connected in series may be arranged along other directions as long as they are parallel to the XY plane and different from the transport direction.

(Second embodiment)
As a second embodiment, another example of an ultraviolet irradiation device is shown. FIG. 11 is a plan view of an ultraviolet irradiation apparatus 40A as another example.
This ultraviolet irradiating device 40A is the same in other respects (arrangement of each ultraviolet LED 41 in the LED array 42, etc.) except that the connection method between the ultraviolet irradiating device 40 and each ultraviolet LED 41 is different. Further, the same components as those of the ultraviolet irradiation device 40 are denoted by the same reference numerals.

The ultraviolet irradiation device 40 described above is connected in series with a group of ultraviolet LEDs 41 aligned in the lower left diagonal direction as one group. In the ultraviolet irradiation device 40A, ultraviolet light corresponding to two columns aligned in the lower left diagonal direction is connected. The LEDs 41 are connected in series as one group.
That is, the groups are formed such that the ends are connected by wiring, and the total number of individuals of the two connected UV LEDs 41 is the same as that of the diagonal rows. The ultraviolet LEDs 41 forming each group are wired so that energization is performed from the A side (A1 to A13) to the B side (B1 to B13).

As a result, the number of UV LED 41 groups in the UV irradiation device 40A is approximately half the number of UV LED 41 groups in the UV irradiation device 40, and the number of UV LEDs 41 connected in series in each group is made uniform. Therefore, it is possible to use the energization units 50 connected to each group having the same characteristics.
Therefore, the ultraviolet irradiation device 40A can obtain the same technical effect as the ultraviolet irradiation device 40 and can improve productivity by uniformizing parts.

(Third embodiment)
As a third embodiment, another example of an ultraviolet irradiation device is shown. 12A is a plan view of an ultraviolet irradiation apparatus 40B as another example, and FIG. 12B is a plan view showing a state in which the recording medium P is conveyed below the ultraviolet irradiation apparatus 40B.
This ultraviolet irradiating device 40B is the same as the other (arrangement of each ultraviolet LED 41 in the LED array 42, etc.) except that the connection method between the ultraviolet irradiating device 40 and each ultraviolet LED 41 is different. Further, the same components as those of the ultraviolet irradiation device 40 are denoted by the same reference numerals.

The ultraviolet irradiation device 40 described above is connected in series with a group of ultraviolet LEDs 41 arranged in a diagonally lower left direction as one group. In the ultraviolet irradiation device 40B, a plane parallel to the recording medium P to be conveyed is used. In FIG. 1, the UV LEDs 41 for one row aligned along the direction orthogonal to the transport direction F (Y-axis direction) are connected in series as one group. The ultraviolet LEDs 41 forming each group are wired so that energization is performed from the A side (A1 to A13) to the B side (B1 to B13).
As a result, the number of UV LED 41 groups in the UV irradiation device 40B is approximately half of the number of UV LED 41 groups in the UV irradiation device 40 (the same number as that of the UV irradiation device 40A described above). It is possible to make the number of ultraviolet LEDs 41 to be uniform, and it is possible to use exactly the same energization unit 50 connected to each group.
Therefore, the ultraviolet irradiation device 40B can obtain the same technical effect as the ultraviolet irradiation device 40 and improve the productivity.

(Fourth embodiment)
As the fourth embodiment, another example of the ultraviolet irradiation device is shown. FIG. 13 is a plan view of an ultraviolet irradiation apparatus 40C as another example.
The ultraviolet irradiation device 40C includes two LED arrays 42a and 42b that are the same as the ultraviolet irradiation device 40 described above, and a movable mechanism 60C that can individually move these along the Y-axis direction, and the recording that is conveyed. The point provided with the width detection unit 65C that detects the width in the Y-axis direction of the medium P is different from the control content performed by the control unit 70, and other configurations are the same as those of the ultraviolet irradiation device 40. is there. Further, the same components as those of the ultraviolet irradiation device 40 are denoted by the same reference numerals.

The two LED arrays 42a and 42b have the same structure as the LED array 42 of the ultraviolet irradiation device 40, and the groups of the ultraviolet LEDs 41 are formed along the same 45 ° direction.
The movable mechanism 60C supports each LED array 42a, 42b by a slide guide (not shown) so as to be slidable along the Y-axis direction, and two actuators (not shown) for individually moving and positioning the LED arrays 42a, 42b. Abbreviation). Each actuator is not particularly limited as long as the amount of operation can be controlled. For example, a rotary stepping motor or a servo motor and a combination of a conversion mechanism that converts a rotation operation into a straight operation may be used, or a linear motor that performs a straight operation. Alternatively, a voice coil motor or the like may be used. In either case, these actuators are connected to the control unit 70 via a motor driver, and their operation amounts are individually controlled.
Further, the movable mechanism 60 </ b> C has two LED arrays 42 a and 42 b arranged adjacent to each other along the conveyance direction of the recording medium P.

  The width detection unit 65C is located upstream of the movable mechanism 60C in the conveyance direction of the recording medium P, and a light source that irradiates light to the passage region of the recording medium P from above and a width direction (Y-axis direction). The width detection unit 65C receives the reflected light from the recording medium P that passes through the irradiation from the light source and detects the width thereof. To do. The width of the recording medium P detected by the width detector 65C is output to the controller 70.

The control unit 70 performs irradiation control for selecting and lighting a group of ultraviolet LEDs 41 in accordance with the width of the recording medium P to be conveyed with respect to the ultraviolet irradiation device 40C having the above configuration.
That is, when the recording medium P is narrower than the width of the single LED array 42a or 42b in the Y-axis direction, the LED arrays 42a and 42b are moved in the opposite directions along the Y-axis direction by the movable mechanism 60C in the irradiation control. Move. Then, the movable mechanism 60C is controlled so that the width of the portion where the LED arrays 42a and 42b overlap each other in the Y-axis direction matches the width of the recording medium P.

  Furthermore, the region of the right triangle is turned on by turning on the ultraviolet LEDs 41 belonging to a plurality of groups from the corner on one side in the width direction (for example, the right side in FIG. 13) at the downstream end of the LED array 42a in the transport direction. Similarly, the same right triangle is obtained by turning on the ultraviolet LEDs 41 belonging to a group of a plurality of groups from the corner on the opposite side in the width direction (for example, the left side in FIG. 13) at the upstream end in the transport direction of the LED array 42b. Turn on the area. At this time, the light emitting areas of the right triangles of the respective LED arrays 42a and 42b are in a state where they are opposite to each other by 180 degrees around the Z axis and are in contact with the same base, and are adjacent to each other as shown in FIG. A light emitting region having a shape is formed.

  Then, the group of the ultraviolet LEDs 41 that are turned on is specified so that the width in the Y-axis direction of the light emission region of the parallelogram coincides with the width of the recording medium P detected by the width detector 65C. It is determined how many groups from the corners are lit for each LED array 42a, 42b, and each energization unit 50 is controlled. As a result, the ultraviolet LED 41 on the outer side in the width direction of the recording medium P can be turned off, and unnecessary power consumption due to the lighting of the ultraviolet LED 41 that does not contribute to the curing of the ultraviolet curable ink can be avoided, thereby saving power. It is possible.

  Further, as shown in FIG. 13, in the light emission area of the parallelogram, since the number of light emission of the ultraviolet LED 41 in the transport direction F is uniform in the entire width of the recording medium P, the ultraviolet curing of the recording medium P is made uniform. It is possible to plan.

Note that when the recording medium P is irradiated with ultraviolet rays in the light emission area of the parallelogram as described above, the area of the right triangle becomes smaller as the width of the recording medium P becomes narrower. The number also decreases.
Therefore, when the recording medium P is always transported at a constant transport speed, the amount of ultraviolet irradiation is reduced as the width of the recording medium P becomes narrower.
Accordingly, when the width of the recording medium P is narrowed so that the irradiation amount of the ultraviolet rays does not become insufficient due to the width of the recording medium P, the duty ratio is increased to increase the amount of light in each ultraviolet LED 41, and the recording medium. It is desirable to control the irradiation amount of P so as to maintain a constant level.
Accordingly, the control unit 70 includes a table in which the width of the recording medium P and a duty ratio appropriate for the width are determined. When performing irradiation control, each control unit 70 has a light amount corresponding to the width of the recording medium P. The PWM control unit 51 is controlled.
In this case as well, the conveyance speed may be switched to a low speed instead of compensating for the shortage of the irradiation amount by increasing the light quantity of each ultraviolet LED 41.

FIG. 14 is a flowchart showing printing control including irradiation control for the ultraviolet irradiation device 40C performed by the control unit 70.
As illustrated, when the recording medium P is transported to the width detection unit 65C, the control unit 70 detects the width of the recording medium P through the width detection unit 65C (step S21).
When the detected width of the recording medium P is acquired, the control unit 70 controls the movable unit 60C so that the width of the overlapping portion of the LED arrays 42a and 42b matches the detected width of the recording medium P. The LED arrays 42a and 42b are moved (step S23).
Next, the control unit 70 specifies a group of ultraviolet LEDs 41 for lighting a right-angled triangular region in which the base length matches the width of the recording medium P in each of the LED arrays 42a and 42b (step S25).
Further, the control unit 70 refers to the duty ratio table and acquires the duty ratio according to the width of the recording medium P (step S27). Then, control for the PWM control unit 51 is started so as to achieve the duty ratio, and ultraviolet irradiation is performed in the light emission region of the parallelogram corresponding to the width of the recording medium P (step S29).

The ultraviolet irradiation device 40C moves the two LED arrays 42a and 42b relative to each other in the Y-axis direction by the movable portion 60C, so that the recording medium having a width wider than the width of the LED arrays 42a and 42b alone in the Y-axis direction. It is also possible to irradiate P with ultraviolet rays.
In that case, when the width of the recording medium P is detected by the width detection unit 65C, the LED arrays 42a and 42b are moved in opposite directions by the movable unit 60C, and the total width of the two LED arrays 42a and 42b is The movable portion 60C is controlled so as to match the width of the recording medium P.
In this case, the overlapping portions of the LED arrays 42a and 42b have two UV LEDs 41 arranged in the transport direction F, so that when all of them are lit, the irradiation amount is larger than that of the non-overlapping portions. Since it becomes excessive, each energization part 50 is controlled so that a part is extinguished.
That is, as shown in FIG. 15, when the width of the recording medium P is narrower than the array width, only the right triangle area is lit for each of the LED arrays 42a and 42b, but the width of the recording medium P is larger than the array width. If it is wide, the LED arrays 42a and 42b are controlled to turn off only the right triangle area.
In this case, 13 portions of the ultraviolet LEDs 41 that are lit along the transport direction F are arranged in the non-overlapping portions of the LED arrays 42a and 42b, and the portion of the LED arrays 42a and 42b that is lit along the transport direction F is aligned. Since 18 LEDs 41 are arranged, the amount of irradiation at the center overlapping portion is increased, and the ultraviolet rays are not uniformly irradiated over the entire width of the two LED arrays 42a and 42b. In this case, the duty ratio of the ultraviolet LED 41 is set so that the irradiation amount of the portion where no overlap occurs is sufficient for ink curing. As a result, the UV irradiation amount exceeds the required amount in the overlapping portion, but there is no influence on the UV curable ink unless the irradiation amount is insufficient.
In this case, since the amount of ultraviolet irradiation in the portion where the LED arrays 42a and 42b overlap is larger than the necessary amount, the power saving is inhibited, but all the two LED arrays 42a and 42b Since some of the ultraviolet LEDs 41 are extinguished as compared with the case where they are turned on, power saving can be achieved according to the width of the recording medium P.

In the ultraviolet irradiation device 40C, the width detection unit 65C is disposed immediately in front of the LED arrays 42a and 42b. However, the present invention is not limited to this, and may be provided further upstream. In this case, since the width of the recording medium P can be detected at an earlier stage, the movement of the LED arrays 42a and 42b and the specification / lighting of the ultraviolet LEDs 41 can be executed earlier.
In the ultraviolet irradiation device 40C, the width detection unit 65C is provided to detect the width of the recording medium P. However, the operator reads the recording medium width preset in the data for printing, or the operator, for example, the PC 17 For example, the irradiation range may be specified based on the width of the recording medium on which the setting input has been performed.

  In the above example, the ultraviolet irradiation area is controlled based on the width of the recording medium P itself. However, the ultraviolet irradiation area is controlled based on the width of the recording image formed on the recording surface of the recording medium P. May be. Also in this case, the width detection unit 65C may detect the boundary position based on the difference in the brightness value of the reflected light between the printing unit and the non-printing unit to detect the width of the recorded image. Further, the width of the recording image set in the data for printing described above or the width of the recording image set and input by the operator may be read and acquired.

(Application examples)
In the first embodiment, the second disconnection process is applied to a group in which a plurality of ultraviolet LEDs 41 are connected in series. However, the ultraviolet LEDs 41 are not connected in series and are individually energized individually. It is also applicable to cases where
FIG. 16 is a plan view showing an application example in which the second disconnection process is applied when energization is performed individually for each ultraviolet LED.
An energization unit 50 is provided for each ultraviolet LED 41 provided in the LED array 42D, and a disconnection detection unit 52 is provided for each ultraviolet LED 41 individually.
And when disconnection generate | occur | produces in any ultraviolet LED41 (FIG. 16 (A)), only the said ultraviolet LED41 will go out. When the disconnection of the ultraviolet LED 41 is recognized by the control unit 70 via the disconnection detection unit 52, the control unit 70 energizes the ultraviolet LED 41 adjacent to the ultraviolet LED 41 on the upstream side and the downstream side in the transport direction. Control is performed to increase the light emission amount by increasing the duty ratio with respect to the PWM control unit 51 of the unit 50 (FIG. 16B).
Thereby, it is possible to effectively suppress the reduction in the amount of ultraviolet irradiation due to the disconnection of the single ultraviolet LED 41.
In this case, the control unit 70 refers to the position data indicating the position of each ultraviolet LED 41, and the ultraviolet LED 41 whose detection of the disconnection is adjacent to both the position and the conveyance direction of the ultraviolet LED 41 may be specified. When a break occurs in the ultraviolet LED 41, a table that specifies in advance which of the ultraviolet LEDs 41 the light emission intensity is increased is provided, and when the broken ultraviolet LED 41 is identified, the ultraviolet LED 41 that increases the light emission intensity is read with reference to the table. It is good also as a structure.

FIG. 17 is a flowchart showing the disconnection process of the reference example.
As shown in the figure, when printing is started (step S51), the control unit 70 energizes each ultraviolet LED 41 through each PWM control circuit 51 at a predetermined cycle and duty ratio, and turns each ultraviolet LED 41 on. Lights up (step S53).
At this time, the control unit 70 determines whether or not a disconnection has been detected for the disconnection detection unit 52 provided for each ultraviolet LED 41 (step S55).
If any one of the ultraviolet LEDs 41 is disconnected, the disconnection detecting unit 52 detects the disconnection and inputs it to the control unit 70.
Then, the control unit 70 identifies which ultraviolet LED 41 is broken (step S57). The identification can be specified by making the signal type of the detection signal of each disconnection detection unit 52 unique or by the control unit 70 receiving the detection signal from each disconnection detection unit 52 at a separate input port, for example. .
Next, when specifying the ultraviolet LED 41 that has caused the disconnection, the control unit 70 further specifies the ultraviolet LED 41 adjacent on the upstream side and the downstream side in the transport direction of the ultraviolet LED 41 (step S59). In this case, the control part 70 memorize | stores the data of arrangement | positioning of ultraviolet LED41, and specifies the ultraviolet LED 41 adjacent to the ultraviolet LED41 which produced the disconnection with reference to the said data. Or the control part 70 may prepare the table which specified which light emission amount of which ultraviolet LED41 should be increased when a disconnection arises about all the ultraviolet LED41, and may refer this.
Then, the PWM control unit 51 of the adjacent ultraviolet LED 41 is controlled to increase the duty ratio, and the light emission amount of the adjacent ultraviolet LED 41 is increased.
In step S55, if no disconnection is detected from any of the disconnection detectors 52, the disconnection process ends and normal ultraviolet irradiation is performed as it is.

  In addition, although control which increases the light emission amount of the bidirectional | two-way ultraviolet LED41 of the conveyance direction upstream and downstream of the ultraviolet LED41 which produced the disconnection is performed, you may raise the light emission amount only to the ultraviolet LED41 of one side instead of both sides. In this case as well, the conveyance speed may be switched to a low speed instead of compensating for the shortage of the irradiation amount by increasing the light quantity of each ultraviolet LED 41.

10 Inkjet recording device 17 PC (notification means)
20 Recording head 30 Conveying device 40, 40A, 40B, 40C, 40D UV irradiation device 41 UV LED
42, 42a, 42b LED array (unit)
50 energization unit 51 PWM control unit 52 disconnection detection unit 60C movable mechanism 65C width detection unit 70 control unit (light emission control unit, first light emission control unit, second light emission control unit, third light emission control unit, transport control unit )
F Transport direction P Recording medium

Claims (12)

A recording head that discharges ultraviolet curable ink; and
A conveying device that conveys a recording medium to a position facing the ink ejection surface of the recording head;
Inkjet including an ultraviolet irradiation device that is provided on the downstream side of the recording head in the conveyance direction in which the conveyance device conveys a recording medium, and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. In the recording device,
The ultraviolet irradiation device forms a plurality of groups in which a plurality of light emitting elements arranged in a direction different from the transport direction on a plane parallel to the recording medium transported by the transport device are connected in series, and each of the groups An ink jet recording apparatus comprising an energization unit for energizing the printer. A recording head that discharges ultraviolet curable ink; and
A conveying device that conveys a recording medium to a position facing the ink ejection surface of the recording head;
Inkjet including an ultraviolet irradiation device that is provided on the downstream side of the recording head in the conveyance direction in which the conveyance device conveys a recording medium, and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. In the recording device,
The ultraviolet irradiation device has a plurality of light emitting elements arranged in a direction different from the transport direction on a plane parallel to the recording medium transported by the transport device and obliquely intersecting the transport direction An ink jet recording apparatus comprising: a plurality of groups connected in series; and an energization unit configured to energize each of the groups. A recording head that discharges ultraviolet curable ink; and
A conveying device that conveys a recording medium to a position facing the ink ejection surface of the recording head;
Inkjet including an ultraviolet irradiation device that is provided on the downstream side of the recording head in the conveyance direction in which the conveyance device conveys a recording medium, and includes a plurality of light emitting elements arranged two-dimensionally in a conveyance direction and a direction orthogonal to the conveyance direction. In the recording device,
The ultraviolet irradiation device includes a plurality of light emitting elements arranged in series in a direction different from the transport direction on a plane parallel to the recording medium transported by the transport device and orthogonal to the transport direction. An ink jet recording apparatus comprising: a plurality of connected groups, and an energization unit that energizes each of the groups. Two units each holding the plurality of light emitting elements are arranged side by side in the conveyance direction of the recording medium,
A movable mechanism that enables movement of at least one unit along a direction orthogonal to the conveyance direction of the recording medium;
The energization unit is capable of energization in units of light emitting elements arranged in a row among the plurality of light emitting elements connected in series,
The energizing unit is controlled so that the same triangular area emits light in the opposite directions with respect to each unit, and the triangular area is a recording image formed on the width of the recording medium or on the recording surface of the recording medium. The inkjet recording apparatus according to claim 2, further comprising: a light emission control unit that controls the movable mechanism so as to be a parallelogram region that matches the width of the ink. A width detector for detecting the width of the recording medium being conveyed or the width of a recording image formed on the recording surface of the recording medium;
The light emission control unit controls the energization unit and the movable mechanism so that the width of the detected recording medium or the width of the area where the recording is performed becomes a parallelogram area that matches the width. The inkjet recording apparatus according to claim 4, further comprising: a light emission control unit. Two sets of units each holding the plurality of light emitting elements in a rectangular plane are arranged in the transport direction of the recording medium,
A movable mechanism that enables movement of at least one unit along a direction orthogonal to the conveyance direction of the recording medium;
When the width of the recording medium or the width of the recording image formed on the recording surface of the recording medium is wider than the width of the unit alone, the units are shifted in the width direction so as to match the width, The inkjet recording apparatus according to claim 2, further comprising a light emission control unit that performs control for the movable mechanism.   7. A second light emission control unit that controls the amount of irradiation light based on information on the number of light emitting elements connected to each column of the plurality of light emitting elements connected in series. The ink jet recording apparatus according to any one of the above. Provided with a disconnection detector for detecting disconnection for each column of the plurality of light emitting elements connected in series,
With respect to the energization unit that allows energization for each column of the plurality of light emitting elements connected in series, the disconnection is detected except for the column of the light emitting elements in which the disconnection detection unit has detected disconnection. A third light emission control unit is provided for performing control so that the amount of irradiation light is increased with respect to the row of light emitting elements positioned upstream or downstream in the transport direction with respect to the row of light emitting elements. Item 8. The ink jet recording apparatus according to any one of Items 1 to 7. Provided with a disconnection detector for detecting disconnection for each column of the plurality of light emitting elements connected in series,
When the disconnection detection unit detects a disconnection in any one of the light emitting element rows, the disconnection detection unit includes a transport control unit that controls the transport device so that the speed is lower than when no disconnection is detected. The ink jet recording apparatus according to claim 1. Provided with a disconnection detector for detecting disconnection for each column of the plurality of light emitting elements connected in series,
The inkjet recording apparatus according to claim 1, further comprising a notification unit that warns of a disconnection when a disconnection is detected by the disconnection detection unit.   11. The ink jet recording apparatus according to claim 10, wherein the disconnection warning is performed only at the first recording per day.   The inkjet recording apparatus according to any one of claims 1 to 11, wherein the energization unit performs energization control to the light emitting elements by PWM control.

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