JP2024045796A - Printing device - Google Patents

Abstract

[Problem] In a printing device, the transport direction of a print substrate is quickly and accurately determined, and the printing unit is controlled based on the transport direction. [Solution] The printing device (inkjet printing device 1) includes a printing unit (inkjet head 10) that prints on the print substrate M, and a control unit 21 that determines the transport directions D1, D2 of the print substrate M based on the phase difference of an encoder 110 provided on a transport device (conveyor 100) that transports the print substrate M, and controls the printing unit based on the determined transport directions D1, D2. [Selected Figure] Figure 3

Description

The present invention relates to a printing device that prints on a substrate based on a determined transport direction.

A printing device has been proposed that selectively uses a first printing mode in which one end of the print head in the main scanning direction is used as the reference position for printing, and a second printing mode in which the other end is used as the reference position for printing, and prints by reversing the printing direction of the image between the first printing mode and the second printing mode (see, for example, Patent Document 1).

JP 2020-203449 A

However, some transport devices, such as conveyors that transport printed materials such as cardboard, are capable of switching the transport direction of the printed material between left and right. In a printing device that prints on a printed material transported by such a transport device, there are restrictions on the placement of the printing unit, and it becomes necessary to prepare two printing units, one dedicated to the left direction and one dedicated to the right direction.

Note that it is conceivable to control the printing section by determining the conveying direction of the printing material based on the position of the printing material detected by a sensor, but such control of the printing section based on the position of the printing material is Since the detection sensor is placed immediately before the printing section, image processing may not be able to keep up after acquiring the detection signal of the printing material. Further, for example, there is a problem that it takes time from the start of conveyance of the printing medium to the determination of the conveyance direction, making it impossible to control the printing unit immediately after the start of conveyance of the printing medium.

The object of the present invention is to provide a printing device that can quickly and accurately determine the transport direction of the printed material and control the printing unit based on the transport direction.

In one aspect, the printing device includes a printing unit that prints on a substrate, and a control unit that determines the transport direction of the substrate based on the phase difference of an encoder provided on a transport device that transports the substrate, and controls the printing unit based on the determined transport direction.

According to the aspect, it is possible to quickly and accurately determine the conveyance direction of the printing material, and to control the printing section based on the conveyance direction.

1 is a perspective view showing an inkjet printing apparatus (transport direction is to the left) according to an embodiment. It is a perspective view showing an inkjet printing device (conveyance direction is rightward) in one embodiment. FIG. 1 is a block diagram showing a control configuration of an inkjet printing apparatus according to an embodiment. FIG. 3 is an explanatory diagram for explaining a phase difference of an encoder in one embodiment. 4 is a flowchart illustrating control of an inkjet head in one embodiment. FIG. 11 is an explanatory diagram for explaining control of the inkjet head (transport direction is leftward) in one embodiment. FIG. 2 is an explanatory diagram for explaining control of an inkjet head (the transport direction is rightward) in one embodiment. FIG. 3 is an explanatory diagram for explaining a reference position of image data in one embodiment. 13A and 13B are explanatory diagrams illustrating an inkjet head according to a modified example of the embodiment. FIG. 7 is a front view showing an inkjet head in another embodiment. FIG. 3 is a block diagram showing a control configuration of an inkjet printing device in another embodiment. FIG. 7 is an explanatory diagram (Part 1) for explaining control of a first fan and a second fan in another embodiment. FIG. 11 is a second explanatory diagram for explaining control of the first fan and the second fan in another embodiment. FIG. 7 is an explanatory diagram (part 3) for explaining control of the first fan and the second fan in another embodiment.

The printing device according to the embodiment of the present invention will be described below with reference to the drawings, using an inkjet printing device as an example.

<One embodiment>
1 and 2 are perspective views showing an inkjet printing apparatus 1. FIG.

FIG. 3 is a block diagram showing the control configuration of the inkjet printing apparatus 1. As shown in FIG.

1 and 2, as well as FIGS. 6A, 6B, 8, 9, and 11A to 11C, which will be described later, the front and rear, left and right, and up and down directions correspond to the transport directions D1 and D2 of the conveyor 100. This is an example for convenience of explanation when the left direction and the right direction are used, and the front-rear direction and the left-right direction are horizontal directions, and the up-down direction is a vertical direction.

As shown in Figures 1 to 3, the inkjet printing device 1 includes an inkjet head 10, a first sensor 31, and a second sensor 32. As shown in Figure 3, the inkjet printing device 1 further includes a control unit 21, a memory unit 22, and an interface unit 23. The inkjet printing device 1 is disposed on the front side of the conveyor 100. Here, a system including the inkjet printing device 1 (printing device) and the conveyor 100 (transport device) can be called a printing system.

As shown in Figures 6A and 6B described later, the inkjet head 10 has a plurality of heads 11, each of which is provided with a plurality of nozzles 11a that eject ink. The nozzles 11a are an example of an ejection section. The inkjet head 10 can also be called a print bar. The inkjet head 10 is preferably connected to an ink supply section, such as an ink circulation section, and is supplied with ink.

The inkjet head 10 is an example of a printing unit that prints on the print substrate M, and the nozzle 11a ejects ink in a lateral direction (rearward) to print on the print substrate M transported on the conveyor 100. The lateral direction in which the nozzle 11a ejects ink is a direction that intersects the vertical direction (up and down direction in FIG. 1) and the transport directions D1 and D2 (left and right directions) of the print substrate M, and is, for example, a horizontal direction. However, the lateral direction is not limited to the horizontal direction, and may be a direction that is inclined up and down with respect to the horizontal direction. The inkjet head 10 may also eject ink downward to print on the print substrate M. The printing unit, which is an example of the inkjet head 10, may be a printing unit other than the inkjet type, such as a thermal type. In this case, the printing device according to this embodiment is a printing device other than the inkjet printing device 1.

As shown in FIGS. 6A and 6B, the inkjet head 10 (illustrated with an imaginary two-dot chain line to represent the head 11 located on the back side) has a plurality of heads 11. For example, the inkjet head 10 has 12 heads 11. Of these 12 heads 11, each of the six heads 11 on the right side has a nozzle row in which nozzles 11a that eject black (K) ink are arranged vertically, and a nozzle row that ejects cyan (C) ink. A nozzle row in which nozzles 11a are arranged in the vertical direction is provided. Of the 12 heads 11, each of the six heads 11 on the left side has a nozzle row in which nozzles 11a for ejecting magenta (M) ink are arranged in the vertical direction, and a nozzle row for ejecting yellow (Y) ink. A nozzle row in which nozzles 11a are arranged in the vertical direction is provided. The above-mentioned six heads 11 are arranged in a staggered manner in the height direction with different positions in the left and right direction (conveying directions D1, D2). As a result, in the inkjet head 10, the plurality of nozzles 11a provided in each head 11 are arranged in the transport directions D1, D2 and in the vertical direction.

As one example, the inkjet head 10 prints, in four colors (full color) - black (K), cyan (C), magenta (M), and yellow (Y) - on the side (front) of the printing substrate M, text such as "XX apple" or "Harvest date * month * day" (where * is variable printing) or a predetermined image such as a pattern of two apples, as shown in Figures 1 and 2.

The conveyor 100 is an example of a conveyance device that conveys the printing material M, and is, for example, a belt conveyor disposed as part of a box making machine. The printing material M is, for example, a three-dimensional object such as a cardboard (box), but is not particularly limited. The conveyor 100 can switch the conveyance directions D1 and D2 between a leftward conveyance direction D1 and a rightward conveyance direction D2. The conveyor 100 is provided with an encoder 110. The encoder 110 is connected to, for example, a conveyance member (belt, pulley, etc.) of the conveyor 100, a drive source (motor, etc.) that drives this conveyance member, a transmission mechanism (gear, etc.) that transmits the power generated by this drive source, etc. It would be nice if it could be installed. Note that the conveyor 100 may be a roller conveyor instead of a belt conveyor. Although not shown in FIGS. 1 and 2, the printing material M conveyed on the conveyor 100 is guided by a conveyance guide arranged on the rear side of the conveyor 100, and the inkjet head 10 is attached to the guided printing material M. It is a good idea to print it.

The control unit 21 shown in FIG. 3 includes a processor (for example, a CPU: Central Processing Unit) that functions as an arithmetic processing unit that controls the operation of the entire inkjet printing apparatus 1, and controls each unit such as the inkjet head 10.

The storage unit 22 has memories such as a ROM (Read Only Memory), which is a read-only semiconductor memory in which a specific control program is pre-recorded, and a RAM (Random Access Memory), which is a semiconductor memory that can be written and read at any time and is used as a working memory area as necessary when the processor executes various control programs.

The interface unit 23 exchanges various information with external devices such as the conveyor 100 (encoder 110), the print control device, and the user terminal. For example, the interface unit 23 receives the output signal of the encoder 110 and a print job including image data to be printed (for example, image data of the character "B" shown in FIG. 7).

The first sensor 31 is disposed on the right side (an example of one side) of the inkjet head 10 in the left-right direction (conveyance directions D1, D2), and the second sensor 32 is disposed on the right side (an example of one side) of the inkjet head 10 in the left-right direction (conveyance directions D1, D2). is placed on the left side (an example of the other side). For example, the first sensor 31 and the second sensor 32 are optical sensors, and detect the printing medium M. In this case, the control unit 21 can determine the conveyance state such as passage of the printing medium M based on the detection signal (detection result) of the presence or absence of the printing medium M output by the first sensor 31 and the second sensor 32. can.

For example, as shown in FIG. 1, when the printing material M is transported in the transport direction D1, which is the left direction, the first sensor 31 is located upstream of the inkjet head 10 in the transport direction D1 and therefore functions as a supply side sensor (paper feed sensor), and the second sensor 32 is located downstream of the inkjet head 10 in the transport direction D1 and therefore functions as a discharge side sensor (paper discharge sensor).

Further, as shown in FIG. 2, when the printing medium M is transported in the transport direction D2, which is the right direction, the first sensor 31 is located downstream of the inkjet head 10 in the transport direction D2, so it is used as a discharge side sensor. Since the second sensor 32 is located upstream of the inkjet head 10 in the transport direction D2, it functions as a supply-side sensor.

The control unit 21 controls the inkjet head 10 based on the detection time when one of the first sensor 31 and the second sensor 32 on the upstream side in the transport direction D1, D2 (supply side sensor) detects the printing medium M. good. Further, the control unit 21 controls the conveyance of the printing medium M based on the fact that one of the first sensor 31 and the second sensor 32 on the downstream side in the transport direction D1, D2 (discharge side sensor) detects the printing medium M. It is a good idea to determine that it is being performed normally.

FIG. 4 is an explanatory diagram for explaining the phase difference of the encoder 110.

In the example shown in FIG. 4, encoder 110 is a rotary encoder that detects rotation of conveyor 100. When the conveyor 100 rotates forward, the B phase rises after the A phase rises in the output signal output from the encoder 110. On the other hand, when the conveyor 100 reverses, the A phase rises after the B phase rises in the output signal output from the encoder 110. Therefore, the control unit 21 can determine the transport directions D1 and D2 of the printing medium M based on the phase difference obtained from the encoder 110. Note that the control unit 21 may determine the conveyance directions D1 and D2 by acquiring information about the conveyance directions D1 and D2 determined by a device on the conveyor 100 side based on the phase difference of the encoder 110. Furthermore, the encoder 110 may be a linear encoder that detects horizontal movement of the conveyor 100.

Figure 5 is a flowchart explaining the control of the inkjet head 10.

Figures 6A and 6B are explanatory diagrams for explaining the control of the inkjet head 10.

As shown in FIG. 5, when conveyance and printing of the printing medium M is started, the control unit 21 first determines the conveyance directions D1 and D2 from the phase difference of the encoder 110 (step S1).

As shown in FIG. 6A, when the control unit 21 determines that the conveyance direction D1 of the printing medium M is the left direction (step S1: D1), the control unit 21 controls the first The inkjet head 10 is controlled based on the detection time when the sensor 31 detected the printing medium M (step S2), and printing is started (step S4).

For example, since the distances a, b, c, d in the transport direction D1 from the first sensor 31 differ for each head 11, the control unit 21 controls the nozzle 11a of the head 11 according to the distances a, b, c, d. Adjust the discharge timing from Note that since two rows of nozzles 11a are provided for each head 11, the distances in the transport direction D1 from the first sensor 31 are different between the nozzles 11a of these two rows, so even if the same head 11 is used, each row of nozzles 11a is different. The ejection timing of the nozzle 11a may also be different.

Next, when the control unit 21 determines that the transport direction D2 of the substrate M is to the right as shown in FIG. 6B (step S1: D2), it controls the inkjet head 10 based on the detection time when the second sensor 32 located upstream of the inkjet head 10 in the transport direction D2 detects the substrate M (step S3), and starts printing (step S4).

For example, the control unit 21 has different distances a, b, c, and d from the second sensor 32 in the conveying direction D2 for each head 11, and even for the same head 11, the example of FIG. 6A (distance from the first sensor 31) Since the distances a, b, c, and d are different from those shown in FIG.

The color of the printed image will be different if the inks are ejected in the order of black (K), cyan (C), magenta (M), and yellow (Y), as in the example of FIG. 6A where the transport direction D1 is to the left, and if the inks are ejected in the opposite order, as in the example of FIG. 6B where the transport direction D2 is to the right. Therefore, in controlling each of the transport directions D1 and D2 (steps S2 and S3), the control unit 21 may not only change the ink ejection timing, but also set a color profile to adjust the color according to the transport directions D1 and D2.

In addition, in the example in which the conveying direction D1 in FIG. 6A is to the left, the control unit 21 controls the control unit 21 to control the reference position P1 at the left end of the image data shown in FIG. 7 (corresponding to the reference position P1 of the lower right end head 11 shown in FIG. ), whereas in the example in which the transport direction D2 in FIG. 6B is in the right direction, the image data is read from the reference position P2 at the right end of the image data shown in FIG. The image data is read from the reference position P2 (corresponding to the reference position P2).

When the printing of the printing medium M is completed, the control unit 21 determines whether there is a next printing medium M (step S5), and if there is a next printing medium M (step S5: YES), the control unit 21 starts the printing process (step S4). ). Further, if there is no next printing medium M (step S5: NO), the control unit 21 ends the process shown in FIG. 5.

In the embodiment described above, the inkjet printing device 1, which is an example of a printing device, includes an inkjet head 10, which is an example of a printing unit that prints on a printing material M, and an example of a conveyance device, which transports the printing material M. A control unit 21 that determines the conveyance directions D1 and D2 of the printing medium M based on the phase difference of an encoder 110 provided on a certain conveyor 100 and controls the inkjet head 10 based on the determined conveyance directions D1 and D2. Be prepared.

In this way, the control unit 21 can control the inkjet head 10 based on the transport directions D1 and D2 of the printing medium M determined from the phase difference of the encoder 110. Therefore, compared to a mode in which a total of two dedicated inkjet heads 10 are arranged in each of the transport directions D1 and D2, the configuration of the inkjet printing apparatus 1 can be simplified and costs can be reduced. Further, since it is possible to omit restrictions on the arrangement of the inkjet printing apparatus 1 according to the transport directions D1 and D2, changing settings, etc., the layout of the inkjet printing apparatus 1 can be easily changed. Furthermore, compared to a mode in which the transport directions D1 and D2 of the print medium M are determined based on the detection result of a sensor that detects the position of the print medium M, the transport direction can be quickly and accurately determined immediately after the start of transport of the print medium M. D1 and D2 can be distinguished. Therefore, according to the present embodiment, the transport directions D1 and D2 of the printing medium M can be quickly and accurately determined, and the inkjet head 10 (printing section) can be controlled based on the transport directions D1 and D2.

Further, in the present embodiment, the inkjet printing apparatus 1 is arranged on the right side (an example of one side) of the inkjet head 10 in the transport directions D1 and D2, and includes a first sensor 31 that detects the printing medium M, and a first sensor 31 that detects the printing medium M, and a , D2 (an example of the other side) of the inkjet head 10, and detects the printing medium M. The control unit 21 controls the inkjet head 10 based on the detection time when one of the first sensor 31 and the second sensor 32 on the upstream side in the transport direction D1, D2 detects the printing medium M.

As a result, one of the first sensor 31 and the second sensor 32 can function as a supply side sensor (paper feed sensor) regardless of the transport direction D1, D2, and the timing of ink ejection from the nozzle 11a can be adjusted. In addition, the other of the first sensor 31 and the second sensor 32 can function as a discharge side sensor (paper discharge sensor) and can be used to determine whether the transport of the printing material M is being performed normally.

<Modification of one embodiment>
FIG. 8 is an explanatory diagram for explaining an inkjet head 50 in a modified example.

The multiple nozzles 51a, which are an example of the ejection section of the head 51 of the inkjet head 50 in this modified example, eject white (W) ink, which is an example of an ink for undercoat printing, in addition to the four colors of ink ejected by the nozzles 11a of the inkjet head 10 shown in Figures 6A and 6B above, namely black (K), cyan (C), magenta (M), and yellow (Y).

8, the inkjet head 50 (illustrated by an imaginary two-dot chain line to represent the head 51 located on the rear side) has a plurality of heads 51. For example, the inkjet head 50 has six heads 51 each provided with two rows of nozzles 51a that eject white (W) and black (K) ink, six heads 51 each provided with two rows of nozzles 51a that eject cyan (C) and magenta (M) ink, and six heads 51 each provided with two rows of nozzles 51a that eject yellow (Y) and white (W) ink. The six heads 51 are arranged in a staggered pattern in the height direction with different left-right positions. As a result, in the inkjet head 50, the nozzles 51a provided in each head 51 are arranged in the transport directions D1 and D2 (left-right direction) and the up-down direction.

Further, in the inkjet head 50, among the plurality of nozzles 51a, the nozzles 51a located at both ends (left end and right end) in the transport directions D1 and D2 eject white (W) ink. Therefore, regardless of whether the transport direction D1 or D2 is the left or right direction, the inkjet head 50 can eject white (W) ink before other inks.

In this modification described above, the inkjet head 50, which is an example of a printing section, has a plurality of nozzles 51a, which are an example of a plurality of ejection sections that are arranged in at least the transport directions D1 and D2 and eject ink. Of the plurality of nozzles 51a, the nozzles 51a located at both ends in the transport directions D1 and D2 eject white (W) ink, which is an example of base printing ink.

As a result, regardless of whether the transport direction D1 or D2 is left or right, the nozzle 51a of the inkjet head 50 can eject white (W) ink before other inks to perform base printing. .

<Other embodiments>
FIG. 9 is a front view showing an ink-jet head 10 according to another embodiment.

Figure 10 is a block diagram showing the control configuration of an inkjet printing device 2 in another embodiment.

The inkjet printing device 2 in this embodiment is the same as the inkjet printing device 1 in the above-described embodiment, except that it further includes a first duct 61, a second duct 62, a first fan 71, and a second fan 72. can be made identical to Therefore, detailed explanation will be omitted.

The first duct 61 shown in FIG. 9 is disposed to the right (one side) of the inkjet head 10 (nozzle 11a shown in FIG. 6A and FIG. 6B, which is an example of an ejection section) in the transport directions D1 and D2, and forms a flow path for air sucked in by the first fan 71 shown in FIG. 10. The second duct 62 is disposed to the left (the other side) of the inkjet head 10 (nozzle 11a) in the transport directions D1 and D2, and forms a flow path for air sucked in by the second fan 72.

The first fan 71 sucks the mist of ink ejected by the nozzle 11a from the right side of the inkjet head 10 through the first duct 61. The second fan 72 sucks the mist of ink ejected by the nozzle 11a from the left side of the inkjet head 10 through the second duct 62. The first duct 61 and the second duct 62 may be provided one each inside the inkjet head 10, or multiple each (for example, on the upstream and downstream sides of each of the four rows of heads 11 aligned in the transport directions D1 and D2). Even in this case, the first fan 71 and the second fan 72 can suck the mist from both sides of the nozzle 11a in the transport directions D1 and D2. The first fan 71 and the second fan 72 may suck the mist from both sides of the inkjet head 50 (nozzle 51a) in the transport directions D1 and D2 in the modified example shown in FIG. 8 described above.

The control unit 21 controls the first fan 71 and the second fan 72 based on the transport directions D1 and D2. For example, in the case where the transport direction D1 is the left direction as shown in FIG. 11A to FIG. 11C, when the inkjet head 10 is ejecting ink as shown in FIG. 11A, the control unit 21 causes the second fan 72 connected to the second duct 62 located downstream of the transport direction D1 to suck in the mist that flows from the inkjet head 10 in the transport direction D1 (left direction) due to the airflow accompanying the transport of the print material M (first control). In this first control, if the mist is also sucked in from the upstream side of the transport direction D1, the landing accuracy of the ink will deteriorate due to turbulence in the airflow, so the control unit 21 may stop the first fan 71 connected to the first duct 61 located upstream of the transport direction D1.

Further, as shown in FIG. 11B, when there is no printing material M facing the inkjet head 10, the control unit 21 connects to the first duct 61 on the upstream side in the transport direction D1 in order to suck the diffused mist. The mist is sucked by both the first fan 71 that has been moved and the second fan 72 that is connected to the second duct 62 on the downstream side in the transport direction D1 (second control).

Also, as shown in FIG. 11C, when the inkjet head 10 is not ejecting ink and the printing material M is in a position facing the first duct 61 upstream of the inkjet head 10, the control unit 21 may suck in mist from the downstream second duct 62 while causing the first fan 71 connected to the first duct 61 to blow air to generate an airflow that passes through the gap between the printing material M and the second duct 62 in order to assist in the suction of mist from the second duct 62 (third control). In this case, the air blown out by the first fan 71 can also blow away dust and other particles adhering to the printing material M.

The control unit 21 may repeat the first control, the second control, and the third control, or may repeat only the first control and the second control, each time one printing material M is transported. The first fan 71 and the second fan 72 may at least suck in air (mist) and blow out air, but may only blow out air. In this case, the control unit 21 may blow out dust adhering to the printing material M, for example, by causing the first fan 71 and the second fan 72 located at least upstream of the nozzle 11a in the transport directions D1 and D2 to blow out air.

In the other embodiments described above, the same effects as in the above-described one embodiment can be achieved, namely, the conveyance directions D1 and D2 of the printing medium M can be quickly and accurately determined, and the conveyance directions D1 and D2 can be quickly and accurately determined. Effects such as being able to control the inkjet head 10 (printing section) based on the following can be obtained.

In the present embodiment, the inkjet head 10, which is an example of a printing unit, has an ejection unit (nozzle 11a shown in Figures 6A and 6B) that ejects ink. The inkjet printing device 1 further includes a first fan 71 that sucks in the mist of ink ejected by the nozzle 11a (inkjet head 10) from one side of the nozzle 11a in the transport directions D1 and D2, and a second fan 72 that sucks in the mist from the other side of the nozzle 11a in the transport directions D1 and D2. The control unit 21 controls the first fan 71 and the second fan 72 based on the transport directions D1 and D2.

As a result, regardless of whether the transport directions D1 and D2 are left or right, it is possible to perform control such as sucking in mist only from the downstream side of the nozzle 11a in the transport directions D1 and D2, as shown in Figure 11A, for example.

The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the gist of the invention in the implementation stage. Various inventions can be formed by appropriately combining the multiple components disclosed in the above-described embodiments. For example, all the components shown in each embodiment can be appropriately combined. Of course, various modifications and applications are possible without departing from the spirit of the invention. The invention described in the claims of this application as originally filed is described below.

[Additional note 1]
a printing section that prints on the substrate;
and a control unit that determines the conveyance direction of the printing medium based on a phase difference of an encoder provided in a conveyance device that conveys the printing medium, and controls the printing unit based on the determined conveyance direction. Characteristic printing device.

[Appendix 2]
a first sensor disposed on one side of the printing unit in the transport direction and configured to detect the printing material;
a second sensor disposed on the other side of the printing unit in the transport direction and configured to detect the printing material;
The printing device according to claim 1, wherein the control unit controls the printing unit based on a detection time at which one of the first sensor and the second sensor, which is upstream in the transport direction, detects the printing substrate.

[Additional note 3]
The printing unit includes at least a plurality of ejection units arranged in the transport direction and ejecting ink,
The printing device according to appendix 1 or 2, wherein the ejection portions located at both ends of the transport direction among the plurality of ejection portions eject base printing ink.

[Additional note 4]
The printing section has a discharge section that discharges ink,
The printing device includes:
a first fan that sucks ink mist ejected from the ejection section from one side of the ejection section in the transport direction;
further comprising: a second fan that sucks the mist from the other side of the discharge section in the transport direction;
The printing apparatus according to appendix 1 or 2, wherein the control unit controls the first fan and the second fan based on the transport direction.

REFERENCE SIGNS LIST 1, 2 Inkjet printing device 10 Inkjet head 11 Head 11a Nozzle 21 Control unit 22 Memory unit 23 Interface unit 31 First sensor 32 Second sensor 50 Inkjet head 51 Head 51a Nozzle 61 First duct 62 Second duct 71 First fan 72 Second fan 100 Conveyor 110 Encoder D1, D2 Transport direction M Printing material P1, P2 Reference position

Claims (4)

A printing unit that prints on a substrate;
a control unit that determines a transport direction of the printing substrate based on a phase difference of an encoder provided in a transport device that transports the printing substrate, and controls the printing unit based on the determined transport direction. a first sensor disposed on one side of the printing unit in the transport direction and configured to detect the printing material;
a second sensor disposed on the other side of the printing unit in the transport direction and configured to detect the printing material;
The printing device according to claim 1 , wherein the control unit controls the printing unit based on a detection time at which one of the first sensor and the second sensor, which is located upstream in the transport direction, detects the printing substrate. The printing unit includes at least a plurality of ejection units arranged in the transport direction and ejecting ink,
The printing apparatus according to claim 1 or 2, wherein among the plurality of ejection units, ejection units located at both ends in the transport direction eject base printing ink. The printing section has a discharge section that discharges ink,
The printing device includes:
a first fan that sucks ink mist ejected from the ejection section from one side of the ejection section in the transport direction;
further comprising: a second fan that sucks the mist from the other side of the discharge section in the transport direction;
The printing apparatus according to claim 1 or 2, wherein the control unit controls the first fan and the second fan based on the transport direction.

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