JP2019018457A - Inkjet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To identify a stray light and its path without causing clogging of a head. An inkjet printer 1 includes a head 30 that ejects ultraviolet curable ink toward a recording medium 9, a main scanning direction driving mechanism 22 that moves the head 30 in the main scanning direction, and a head 30 in the main scanning direction. The ultraviolet irradiator 40L, which is arranged side by side and moves in the main scanning direction together with the head 30 by the main scanning direction driving mechanism 22 and irradiates ultraviolet rays toward the recording medium 9, and the main scanning together with the head 30 by the main scanning direction driving mechanism 22. It is provided with an inspection light irradiator 50L that moves in a direction and irradiates an inspection light having a wavelength outside the wavelength band that cures the ultraviolet curable ink toward the recording medium. [Selection diagram] Fig. 1

Description

  The present invention relates to an inkjet printer.

  Patent Document 1 discloses a serial head type ink jet printer. The inkjet printer includes a table on which a recording medium is placed, a guide rail extending in the left-right direction above the table, and a head attached to the guide rail and movable in the left-right direction along the guide rail. And an ultraviolet irradiator provided adjacent to the left and right sides of the head, a left / right drive mechanism for driving the head and the ultraviolet irradiator in the left / right direction, and a front / rear drive mechanism for driving the guide rail in the front / rear direction. The guide rail is intermittently driven by the front-rear drive mechanism, and the head and the ultraviolet irradiator are driven in the left-right direction by the left-right drive mechanism while the ultraviolet irradiator is lit while the guide rail is stopped each time. When the head moves in the left-right direction, ink is ejected from the nozzles of the head to the recording medium, and ultraviolet rays emitted downward from the ultraviolet irradiator toward the recording medium irradiate the ink on the recording medium. Then, the ink is cured by ultraviolet rays and fixed on the recording medium.

Japanese Patent Laid-Open No. 2015-37870

  By the way, ultraviolet rays are reflected by the surface of a member arranged around the recording medium, for example, a support for the recording medium or a mounting jig for fixing the recording medium (hereinafter referred to as a jig). Reflection). In addition, when the jig has a thickness and the jig member is a light-transmitting material, not only the surface reflection but also ultraviolet rays (light rays) that pass through the jig surface and enter the jig. The “light guide” that passes through the inside (thickness portion) of the jig of the light transmissive member occurs. The light guided inside the jig is reflected or diffused in various directions inside the jig, and as a result, the guided light beam is emitted from various points different from the incident point at various angles. Phenomenon occurs inside the jig. Such an optical phenomenon is referred to as “stray light” caused by light guide.

  The head includes a plurality of nozzles for ejecting ink on the lower surface of the head, which is the surface facing the storage medium and the jig. When a part of the stray light generated as a result of the ultraviolet light irradiated from the ultraviolet irradiator toward the recording medium being guided into the jig made of a light transmissive material enters the lower surface of the head from the jig. The ink hardens in the vicinity of the nozzle opening formed on the lower surface of the head, particularly in the region from the nozzle opening to the inner part of the nozzle, resulting in nozzle clogging. In order to prevent the generation of such stray light, it is necessary to specify the cause of stray light generation and the path of the stray light. However, it is difficult to specify the cause and path of stray light.

  Therefore, the present invention has been made in view of the above circumstances, and a problem to be solved by the present invention is to be able to identify stray light and its path without causing clogging of the nozzles of the head. .

A main invention for solving the above problems is a head that discharges ultraviolet curable ink toward a recording medium, a main scanning direction driving mechanism that moves the head in a main scanning direction, and the head in the main scanning direction. An ultraviolet irradiator that is arranged side by side, moves in the main scanning direction together with the head by the main scanning direction driving mechanism, and irradiates ultraviolet rays toward the recording medium, and the main scanning direction along with the head by the main scanning direction driving mechanism. And an inspection light irradiator that moves in the scanning direction and irradiates the recording medium with inspection light having a wavelength outside the wavelength band for curing the ultraviolet curable ink.
Other characteristics of the present invention will be made clear by the description and drawings described later.

According to the present invention, stray light generated by inspection light emitted from the inspection light irradiator can be visually recognized instead of stray light generated by ultraviolet light emitted from the ultraviolet irradiator, and its transmission path can be specified.
Since the wavelength of the inspection light emitted from the inspection light irradiator is outside the wavelength band for curing the UV curable ink, stray light generated by the inspection light emitted from the inspection light irradiator may be incident on the nozzle of the head or its periphery. UV curable ink does not cure. Therefore, it is possible to take measures such as identifying the stray light transmission path without causing clogging of the nozzles and applying a black tape on the jig so as to block the stray light transmission path before printing. .

FIG. 1 is a front view of the inside of the inkjet printer. FIG. 2 is a bottom view of the carriage, ultraviolet irradiator, and visible light irradiator of the inkjet printer. FIG. 3 is a block diagram of the ink jet printer.

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

[1. Inkjet printer configuration]
FIG. 1 is a front view of the inside of a housing of a flat bed type and serial head type ink jet printer 1. FIG. 2 is a bottom view of the carriage 23, the ultraviolet irradiators 40L and 40R, and the visible light irradiators 50L and 50R of the inkjet printer 1. FIG. 3 is a block diagram of the ink jet printer 1. In the following description, the moving direction of the recording medium 9 printed by the inkjet printer 1 is referred to as the sub-scanning direction, the direction perpendicular to the sub-scanning direction is referred to as the main scanning direction, and the main scanning direction and the sub-scanning direction are referred to. The vertical direction is called the vertical direction. The vertical direction is the vertical direction, but is not necessarily the vertical direction. The main scanning direction is sometimes referred to as the left-right direction.

  As shown in FIGS. 1 to 3, the inkjet printer 1 includes a guide rail 11, a sub-scanning direction driving mechanism 12, a support base 13, a guide rail 21, a main scanning direction driving mechanism 22, a carriage 23, A plurality of heads 30, a plurality of light receiving units 35, ultraviolet irradiators 40 </ b> L and 40 </ b> R, visible light irradiators (inspection light irradiators) 50 </ b> L and 50 </ b> R, and a controller 60 are provided.

  As shown in FIG. 1, the guide rail 11 extends in the sub-scanning direction and is attached to the housing. A support base 13 is attached to the guide rail 11, and the support base 13 is guided by the guide rail 11 in the sub-scanning direction. A sub-scanning direction driving mechanism 12 is connected to the support base 13. The sub-scanning direction drive mechanism 12 includes a motor, an encoder, a transmission mechanism, and the like, and moves the support base 13 in the sub-scanning direction.

  The upper surface of the support base 13 is formed in a planar shape extending in the main scanning direction and the sub-scanning direction. A base plate 16 is placed on the support base 13. A jig 14 is stacked on the base plate 16. The jig 14 is a plate-like member in which an opening 15 is formed. The opening 15 is a recess formed on the upper surface of the stack of the base plate 16 and the jig 14. The jig 14 and the base plate 16 are mounted on the support base 13, and the recording medium 9 is fitted into the opening 15 to be surrounded by the jig 14, thereby determining the position of the recording medium 9. The jig 14 and the base plate 16 can be attached to and detached from the support base 13.

The jig 14 and the base plate 16 have a property of transmitting ultraviolet light and visible light. The jig 14 and the base plate 16 may be detachably stacked. Alternatively, the jig 14 and the base plate 16 may be integrated.
The recording medium 9 is, for example, a case or a plate material. The recording medium 9 has a property of shielding ultraviolet light and visible light without transmitting them. However, the recording medium 9 may have a property of transmitting ultraviolet light and visible light.
Since the jig 14 and the base plate 16 are translucent and have a thickness, the light incident on the jig 14 or the base plate 16 is likely to generate stray light inside the jig 14 or the base plate 16.

  A guide rail 21 is provided above the support base 13. The guide rail 21 extends in the main scanning direction and is attached to the housing. A carriage 23 is attached to the guide rail 21, and the carriage 23 is guided by the guide rail 21 in the main scanning direction. A main scanning direction driving mechanism 22 is connected to the carriage 23. The main scanning direction drive mechanism 22 includes a motor, an encoder, a transmission mechanism, and the like, and moves the carriage 23 in the main scanning direction.

  A plurality of heads 30 that are vertically opposed to the support base 13, the base plate 16, the jig 14, and the recording medium 9 are mounted on the carriage 23. These heads 30 are arranged at intervals in the main scanning direction. A plurality of nozzles are formed on the lower surface of the head 30, and the head 30 ejects ink from the nozzles toward the recording medium 9 below, whereby an image is formed on the recording medium 9. The ink ejected by the head 30 is made of an ultraviolet curable resin.

  A plurality of light receiving portions 35 that receive visible light (inspection light) from below are mounted on the carriage 23. The light receiving unit 35 is a visible light sensor that detects visible light received from below. The light receiving unit 35 is an incident part of a light guide such as an optical fiber or a light guide plate, and visible light incident on the light receiving unit 35 is transmitted to the visible light sensor provided at a position different from the light receiving unit 35 by the light guide. It may be guided. In this case, the light guide may be provided from the plurality of light receiving units 35 to one visible light sensor.

  The light receiving portions 35 are arranged in the main scanning direction with an interval therebetween. The heads 30 are arranged between the adjacent light receiving parts 35, and the light receiving parts 35 and the heads 30 are alternately arranged in the main scanning direction. Accordingly, the light receiving portions 35 are disposed adjacent to the left and right sides of the head 30.

  Visible light irradiators 50L and 50R and ultraviolet irradiators 40L and 40R are attached to the left and right sides of the carriage 23, respectively. The left visible light irradiator 50L is disposed adjacent to the left side of the carriage 23, and the left ultraviolet irradiator 40L is disposed adjacent to the left side of the left visible light irradiator 50L. The right visible light irradiator 50R is disposed adjacent to the right side of the carriage 23, and the right ultraviolet irradiator 40R is disposed adjacent to the right side of the right visible light irradiator 50R. As described above, since the visible light irradiators 50L and 50R and the ultraviolet irradiators 40L and 40R are arranged in the main scanning direction and attached to the carriage 23, the ultraviolet irradiators 40L and 40R and the visible light irradiators 50L and 50R are provided. Arranged side by side with the head 30 in the main scanning direction. Further, the ultraviolet irradiators 40L and 40R and the visible light irradiators 50L and 50R are arranged side by side with the light receiving unit 35 in the main scanning direction.

  The ultraviolet irradiators 40L and 40R irradiate ultraviolet rays downward. The wavelength band of the ultraviolet rays emitted from the ultraviolet irradiators 40L and 40R includes at least the wavelength band for curing the ink ejected by the head 30.

  As shown in FIG. 2, the left ultraviolet irradiator 40L includes a plurality of ultraviolet LEDs (light emitting diodes) 41L arranged in a grid in the main scanning direction and the sub-scanning direction. The right UV irradiator 40R also has a grid array of UV LEDs 41R.

  The visible light irradiators 50L and 50R irradiate visible light downward. The wavelength of visible light emitted from the visible light irradiators 50 </ b> L and 50 </ b> R is out of the wavelength band for curing the ink ejected by the head 30.

  The left visible light irradiator 50L includes a plurality of visible light LEDs 51L arranged linearly in the sub-scanning direction. The visible light irradiator 50R on the right also has a visible light LED 51R in a linear array.

The interval W1 between the ultraviolet irradiator 40L and the visible light irradiator 50L on the right side thereof is equal to the interval W2 between the head 30 and the light receiving unit 35 on the right side thereof. That is, the vector directed from the ultraviolet irradiator 40L to the visible light irradiator 50L and the vector directed from the head 30 to the right-side light receiving unit 35 have the same size and direction.
Here, the interval W1 between the ultraviolet irradiator 40L and the visible light irradiator 50L is a center line parallel to the sub-scanning direction through the row of the ultraviolet LEDs 41L closest to the visible light irradiator 50L, and the visible light irradiator 50L. The distance from the center line parallel to the sub-scanning direction through the row of visible light LEDs 51L. The distance W2 between the head 30 and the right-side light receiving unit 35 is the distance between the center line passing through the head 30 and parallel to the sub-scanning direction and the center line passing through the light receiving unit 35 and parallel to the sub-scanning direction. Say.

The interval W3 between the ultraviolet irradiator 40R and the visible light irradiator 50R on the left side thereof is equal to the interval W4 between the head 30 and the light receiving unit 35 on the left side thereof. That is, the vector directed from the ultraviolet irradiator 40R to the visible light irradiator 50R and the vector directed from the head 30 to the light receiving unit 35 on the left are equal in size and direction.
Here, the interval W3 between the ultraviolet irradiator 40R and the visible light irradiator 50R is the center line parallel to the sub-scanning direction through the row of the ultraviolet LEDs 41L closest to the visible light irradiator 50R, and the visible light irradiator 50R. The distance from the center line parallel to the sub-scanning direction through the row of visible light LEDs 51R. The distance W4 between the head 30 and the light receiving unit 35 adjacent to the left is the distance between the center line passing through the head 30 and parallel to the sub-scanning direction and the center line passing through the light receiving unit 35 and parallel to the sub-scanning direction. Say.

  Of the rows of the light receiving portions 35 arranged in the main scanning direction, the light receiving portions 35 other than both ends are referred to as a light receiving portion 35A (see FIG. 2). The distance W5 between the visible light irradiator 50L and the light receiving unit 35A exceeds the distance W6 between the head 30 and the ultraviolet irradiator 40L closest to the ultraviolet irradiator 40L, and the head 30 and the ultraviolet irradiator 40L farthest from the ultraviolet irradiator 40L. Is less than the interval W7. The distance W8 between the visible light irradiator 50R and the light receiving unit 35A exceeds the distance W9 between the head 30 and the ultraviolet irradiator 40R closest to the ultraviolet irradiator 40R, and the head 30 and the ultraviolet irradiator 40R farthest from the ultraviolet irradiator 40R. Is less than the interval W10.

  As shown in FIG. 3, the inkjet printer 1 is provided with a control unit 60 and drivers 61L, 62L, 61R, and 62R. The control unit 60 is a microcomputer having a CPU, RAM, ROM and the like. The controller 60 controls the sub-scanning direction driving mechanism 12 to move the support base 13 in the sub-scanning direction while recognizing the position of the support base 13. Further, the control unit 60 controls the main scanning direction driving mechanism 22 to move the carriage 23 in the main scanning direction while recognizing the position of the carriage 23. In addition, the control unit 60 controls the head 30 so that the head 30 performs a discharge operation.

  The control unit 60 controls the driver 61 so that the driver 61 drives the ultraviolet LED 41L. The ultraviolet LED 41R, the visible light LED 51L, and the visible light LED 51R are also driven by the drivers 62 to 64.

[2. Stray light specific operation of inkjet printer]
The stray light specifying operation of the inkjet printer 1 will be described. The stray light specification means that light is propagated from the visible light irradiators 50L and 50R to the light receiving unit 35 by light guiding instead of unnecessary ultraviolet stray light that propagates from the ultraviolet irradiators 40L and 40R to the lower surface of the head 30 by light guiding. This refers to specifying the stray light of visible light and its path.

  First, when the control unit 60 controls the sub-scanning direction driving mechanism 12 while recognizing the position of the support base 13, the support base 13 moves in the sub-scanning direction and stops.

  Next, the control unit 60 operates the main scanning direction driving mechanism 22 while recognizing the position of the carriage 23, so that the carriage 23 moves to the right. While the carriage 23 is moving, the visible light irradiator 50L is turned on by the controller 60, and the visible light irradiator 50R and the ultraviolet irradiators 40L and 40R are turned off by the controller 60. At this time, the visible light emitted from the visible light irradiator 50 </ b> L is guided by the jig 14 or the base plate 16, so that stray light may be generated inside the jig 14 or the base plate 16. When the stray light enters the light receiving unit 35 from below the light receiving unit 35, the output of the light receiving unit 35 changes, and the control unit 60 recognizes and stores the position of the carriage 23 and the position of the support base 13 at that time. Thereby, generation | occurrence | production of the stray light of the visible light which injects into the light receiving part 35 from the downward direction of the light receiving part 35 can be specified, and the position of the carriage 23 and the support stand 13 which generate | occur | produce such stray light is specified. Can do. When the ultraviolet irradiator 40L is lit at the same position as the position of the visible light irradiator 50L when visible stray light is generated, ultraviolet stray light is generated and the stray light travels from below the head 30 to the bottom surface of the head 30. Is incident on. This is because the interval W1 between the ultraviolet irradiator 40L and the visible light irradiator 50L is equal to the interval W2 between the head 30 and the right-side light receiving unit 35.

  Next, the control unit 60 controls the sub-scanning direction driving mechanism 12 while recognizing the position of the support base 13, whereby the support base 13 moves in the sub-scanning direction and stops.

  Next, the controller 23 controls the main scanning direction driving mechanism 22 while recognizing the position of the carriage 23, whereby the carriage 23 moves to the left. While the carriage 23 is moving, the visible light irradiator 50R is turned on by the control unit 60, and the visible light irradiator 50L is turned off by the control unit 60. At this time, the visible light emitted from the visible light irradiator 50 </ b> R is guided by the jig 14 and the base plate 16, so that stray light incident on the light receiving unit 35 from below the light receiving unit 35 may be generated. When stray light incident on 35 is generated, the output of the light receiving unit 35 changes, and the control unit 60 recognizes and stores the position of the carriage 23 and the position of the support base 13 at that time. As a result, it is possible to specify the generation of stray light that enters the light receiving unit 35 from below the light receiving unit 35, and it is possible to specify the positions of the carriage 23 and the support base 13 where such stray light is generated.

Thereafter, the inkjet printer 1 repeatedly executes the above operation.
Even if visible stray light enters the lower surface of the head 30 from below the head 30, the ink in the nozzles of the head 30 is not cured. This is because the wavelength of visible light is out of the wavelength band for curing the ink.

[3. Instruction operation of inkjet printer]
Since the ink jet printer 1 executes an operation for instructing the stray light generation position after the above stray light specifying operation, the operation will be described.

  The control unit 60 lights one or both of the visible light irradiators 50L and 50R. Then, the control unit 60 controls the main scanning direction driving mechanism 22 while recognizing the position of the carriage 23, thereby moving the carriage 23 to the position stored as described above and stopping. Further, the control unit 60 controls the sub-scanning direction driving mechanism 12 while recognizing the position of the support base 13, thereby moving the support base 23 to the position stored as described above and stopping it. Stray light propagating from the visible light irradiators 50L and 50R to the light receiving unit 35 is generated, and the user can visually recognize the stray light and its route. Then, the user can take measures against stray light. For example, the surface of the jig 14 or the base plate 16 can be masked to block the stray light path.

[4. (Printing operation of inkjet printer)
Next, the printing operation of the inkjet printer 1 will be described.
The printing operation of the inkjet printer 1 is executed by alternately repeating the movement of the support base 13 by a predetermined distance, the movement of the carriage 23 and the ink ejection of the head 30. Specifically, when the control unit 60 intermittently operates the sub-scanning direction driving mechanism 12, the support base 13 and the recording medium 9 are intermittently moved by a predetermined distance in the sub-scanning direction. During each temporary stop of the support base 13 and the recording medium 9, the control unit 60 operates the main scanning direction driving mechanism 22 to move the carriage 23 in the main scanning direction by the main scanning direction driving mechanism 22. When the control unit 60 controls the head 30 during the movement, the head 30 ejects ink.

  During the printing operation, the ultraviolet irradiators 40L and 40R are turned on / off by the controller 60. Specifically, when the head 30 moves to the right, the ultraviolet irradiator 40L is turned on by the control unit 60, and the ultraviolet irradiator 40R is turned off by the control unit 60. On the other hand, when the head 30 moves leftward, the ultraviolet irradiator 40R is turned on by the control unit 60, and the ultraviolet irradiator 40L is turned off by the control unit 60. Note that the visible light irradiators 50L and 50R are turned off by the control unit 60 during the printing operation.

  As described above, when visible stray light is generated, countermeasures are taken, and stray light that enters the head 30 does not occur during the printing operation. Therefore, clogging of the head 30 can be prevented.

[5. effect〕
According to the embodiment of the present invention described above, the following effects can be obtained.

(1) The head 30, the ultraviolet irradiators 40L and 40R, and the visible light irradiators 50L and 50R are integrally moved by the main scanning direction driving mechanism 22. Therefore, the stray light of the visible light emitted from the visible light irradiators 50L and 50R can be generated by turning on the visible light irradiators 50L and 50R. Therefore, visible stray light emitted from the visible light irradiators 50L and 50R can be regarded as ultraviolet stray light reaching the lower surface of the head 30 from the ultraviolet irradiators 40L and 40R. By specifying the visible light stray light and its path, the ultraviolet stray light and its path can be specified. By taking such a countermeasure against stray light, it is possible to prevent ultraviolet stray light reaching the lower surface of the head 30 from the ultraviolet irradiators 40L and 40R during the above-described printing operation. Therefore, clogging of the nozzles of the head 30 can be prevented.
Further, since the wavelength of visible light emitted from the visible light irradiators 50L and 50R is outside the wavelength band for curing the ultraviolet curable ink, the visible light irradiators 50L and 50R are used in the stray light characteristic operation and the instruction operation described above. Even when visible stray light emitted from the head 30 enters the lower surface of the head 30 from below the head 30, the nozzles of the head 30 are not clogged.

(2) In the stray light characteristic operation and the instruction operation described above, the visible light irradiators 50L and 50R are turned on by the control unit 60, but the ultraviolet irradiators 40L and 40R are turned off by the control unit 60. Therefore, clogging of the nozzles of the head 30 due to ultraviolet rays can be suppressed while identifying stray light of visible light emitted from the visible light irradiators 50L and 50R and its path.

(3) The visible light irradiator 50L and the ultraviolet irradiator 40L are arranged adjacent to each other. Therefore, if the stray light of visible light emitted from the visible light irradiator 50L reaches the lower surface of the head 30 or its periphery, the stray light of the visible light and its path are ultraviolet rays that reach the lower surface of the head 30 from the ultraviolet irradiator 40L. Stray light and its path. Similarly, it is assumed that the stray light of visible light reaching the lower surface of the head 30 or its periphery from the visible light irradiator 50R and its path are the stray light of ultraviolet light reaching the lower surface of the head 30 from the ultraviolet irradiator 40R and its path. Can do. Thus, by identifying such visible light stray light and its path, it is possible to identify ultraviolet stray light and its path.

(4) The visible light irradiator 50L is disposed adjacent to the right side of the ultraviolet irradiator 40L, and the light receiving unit 35 is disposed adjacent to the right side of the head 30. Therefore, visible stray light reaching the light receiving unit 35 from the visible light irradiator 50L can be assumed as ultraviolet stray light reaching the lower surface of the head 30 from the ultraviolet irradiator 40L. Furthermore, by detecting the visible stray light reaching the light receiving unit 35 from the visible light irradiator 50L, the visible stray light can be specified. Similarly, by detecting visible stray light reaching the light receiving unit 35 on the left side of the head 30 from the visible light irradiator 50R, the stray light of the visible light is identified and assumed to be ultraviolet stray light. it can.

(5) The vector from the ultraviolet irradiator 40L toward the visible light irradiator 50L and the vector from the head 30 toward the right adjacent light receiving unit 35 are equal in size and direction. Therefore, the accuracy of assuming the stray light of visible light reaching the light receiving unit 35 from the visible light irradiator 50L as stray light of ultraviolet light reaching the lower surface of the head 30 from the ultraviolet irradiator 40L is improved. Similarly, visible stray light reaching the light receiving unit 35 on the left side of the head 30 from the visible light irradiator 50R can be accurately assumed as ultraviolet stray light from the ultraviolet irradiator 40R.

(6) The light receiving portions 35 </ b> A other than both ends in the rows of the light receiving portions 35 arranged in the main scanning direction are disposed between the adjacent heads 30. Therefore, the space between the heads 30 can be effectively used as the installation location of the light receiving unit 35A.

(7) In the light receiving unit 35A, the distance from the visible light irradiator 50L exceeds the distance W6 between the head 30 and the ultraviolet irradiator 40L closest to the ultraviolet irradiator 40L, and the head 30 and the ultraviolet light farthest from the ultraviolet irradiator 40L. It is arranged at a position less than the distance W7 from the irradiator 40L. Therefore, the visible stray light incident on the light receiving unit 35A can be assumed as the ultraviolet stray light of any head 30 from the ultraviolet irradiator 40L.

(8) Since the jig 14 and the base plate 16 are permeable to ultraviolet rays, the ultraviolet rays emitted from the ultraviolet irradiators 40L and 40R are guided by the jig 14 or the base plate 16, so that the ultraviolet stray light is predicted. The light enters the lower surface of the head 30 from a difficult direction. Even in such a case, since the jig 14 and the base plate 16 are transparent to visible light, the visible light stray light passes through the jig 14 or the base plate 16 along the same locus as the ultraviolet stray light. Therefore, visible stray light reaching the light receiving unit 35 from the visible light irradiator 50L can be regarded as ultraviolet stray light reaching the lower surface of the head 30 from the ultraviolet irradiator 40L.

=== Modification ===
As mentioned above, although the form for implementing this invention was demonstrated, the said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. Further, the present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention. Changes from the above embodiment will be described below. The changes described below may be applied in combination as much as possible.

(1) In the above embodiment, the path from the jig 14 and the base plate 16 to the lower surface of the head or the light receiving unit 35 is limited to the stray light caused by the light guide, that is, the stray light generated inside the jig 14 and the base plate 16. However, the present invention is not limited to this, and may be stray light caused by an optical phenomenon other than light guide. For example, reflected light generated on the surfaces or side surfaces of the jig 14 and the base plate 16 by the visible light emitted from the visible light irradiators 50L and 50R, and a path reaching the light receiving unit 35 is also generated inside the jig 14 and the base plate 16. Similar to stray light, the user may visually identify the route by specifying with visible light.

(2) In the above embodiment, when stray light enters the light receiving unit 35 during the stray light specifying operation, the control unit 60 recognizes and stores the position of the carriage 23 and the position of the support base 13 at that time. On the other hand, when visible stray light enters the light receiving unit 35 during the stray light specifying operation, the control unit 60 may control the main scanning direction driving mechanism 22 to stop the carriage 23. If the carriage 23 stops, the stray light incident on the light receiving unit 35 has been generated, and the user can visually recognize the stray light and its route.

(3) In the said embodiment, the light-receiving part 35 was a visible light sensor. On the other hand, the light receiving part 35 is an incident part of the light guide, and the visible light incident on the light receiving part 35 is guided by the light guide to a visible light sensor provided at a position different from the light receiving part 35. Good. In this case, the light guide may be provided from the plurality of light receiving units 35 to one visible light sensor.

(4) In the above embodiment, the visible light irradiators 50L and 50R that irradiate visible light are used. However, irradiation with light other than visible light (however, light that deviates from a wavelength band for curing ink) is used. You may change to a vessel. In this case, the light receiving unit 35 as an optical sensor exhibits sensitivity to light emitted from the irradiator.
For example, the visible light irradiators 50L and 50R may be changed to infrared irradiators, and the light receiving unit 35 may be changed to an infrared sensor.

(5) In the above embodiment, the light receiving unit 35 is provided in the carriage 23, but the light receiving unit 35 may not be provided. In this case, the movement of the support base 13 by a predetermined distance and the low-speed movement of the carriage 23 with the visible light irradiators 50L and 50R turned on are alternately repeated. Thus, when the inkjet printer 1 is operating, the user can visually recognize the stray light of visible light and its path by observing the carriage 23 and its periphery.

(6) In the above embodiment, the support base 13 is guided in the sub-scanning direction by the guide rail 11, and the support base 13 is moved in the sub-scanning direction by the power of the sub-scanning direction driving mechanism 12. On the other hand, the support base 13 may be fixed without moving. In this case, the guide rail 21 is guided in the sub scanning direction by a guide extending in the sub scanning direction. Then, the guide rail 21 moves in the sub-scanning direction together with the carriage 23 by the power of the sub-scanning direction driving mechanism.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet printer, 9 ... Recording medium, 13 ... Support stand, 14 ... Jig, 22 ... Main scanning direction drive mechanism, 30 ... Head, 40R ... Ultraviolet irradiator, 40L ... Ultraviolet irradiator, 50L ... Visible light irradiator (Inspection light irradiator), 50L ... visible light irradiator (inspection light irradiator), 60 ... control unit

Claims (9)

A head for discharging ultraviolet curable ink toward a recording medium;
A main scanning direction driving mechanism for moving the head in the main scanning direction;
An ultraviolet irradiator that is arranged alongside the head in the main scanning direction, moves in the main scanning direction together with the head by the main scanning direction driving mechanism, and irradiates ultraviolet rays toward the recording medium;
An inspection light irradiator that irradiates the recording medium with inspection light having a wavelength outside the wavelength band that moves in the main scanning direction together with the head by the main scanning direction driving mechanism and cures the ultraviolet curable ink;
An inkjet printer comprising: The inkjet printer according to claim 1, further comprising a control unit that operates the main scanning direction driving mechanism in a state where the ultraviolet irradiator is turned off and the inspection light irradiator is turned on. The inkjet printer according to claim 1, wherein the inspection light irradiator is moved in the main scanning direction together with the head by the main scanning direction driving mechanism in a state adjacent to the ultraviolet irradiator. The inkjet according to any one of claims 1 to 3, further comprising a light receiving unit that moves in the main scanning direction together with the head by the main scanning direction driving mechanism in a state adjacent to the head and receives the inspection light. Printer. The inspection light irradiator is arranged side by side with the ultraviolet irradiator in the main scanning direction,
The light receiving unit is arranged alongside the head in the main scanning direction,
The inkjet printer according to claim 4, wherein a direction from the ultraviolet irradiator toward the inspection light irradiator and a direction from the head toward the light receiving unit are the same. The inkjet printer according to claim 5, wherein an interval between the inspection light irradiator and the ultraviolet irradiator is equal to an interval between the light receiving unit and the head. The plurality of heads are moved in the main scanning direction by the main scanning direction driving mechanism in a state in which the plurality of heads are arranged in the main scanning direction, and the main scanning direction driving is performed in a state in which the light receiving unit is disposed between the adjacent heads. The ink jet printer according to claim 4, wherein the ink jet printer moves in a main scanning direction by a mechanism. An interval between the inspection light irradiator and the light receiving unit exceeds an interval between the head and the ultraviolet irradiator that is closest to the ultraviolet irradiator among the plurality of heads, and the ultraviolet irradiator among the plurality of heads. The ink jet printer according to claim 7, wherein a distance between the head farthest from the head and the ultraviolet irradiator is less. The inkjet printer according to any one of claims 1 to 8, further comprising a jig that determines a position of the recording medium, opposes the head, and transmits the ultraviolet light and the inspection light.

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