JP2015131451A - Inkjet printing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that an ink mist amount sucked by a suction fan under a conveyance belt is reduced and ink attachment to an inkjet head or a member around the inkjet head is facilitated when conveyance is performed while narrowing a paper sheet interval in an inkjet printing device.SOLUTION: An inkjet printing device 1 includes: a head holder 32 having a head group on which a plurality of head arrays each comprising an inkjet head 110 are arrayed; a conveyance part 60 which conveys paper sheets P at a first paper sheet interval or a second paper sheet interval narrower than the first paper sheet interval in sub-scanning direction with belt suction fans 131, 132 under a conveyance belt having a vent hole; an ink mist recovery part 150 which is disposed opposite to the upper side of the conveyance belt, forms an air current exhausted from the interior of the head holder 32 and recovers ink mist; and a control part 80 which controls the movement of the ink mist recovery part 150. Therein, the control part 80 moves the ink mist recovery part 150 when the conveyance part 60 conveys paper sheets at the second paper sheet interval.

Description

Embodiments described herein relate generally to an ink jet printing apparatus that reduces paper contamination due to dripping while increasing printing productivity.

The line-type inkjet printing apparatus has a plurality of inkjet heads arranged in the main scanning direction, which is a direction orthogonal to the paper conveyance direction, and ink obtained from image data for the paper conveyed in the sub-scanning direction. Printing is performed on the paper by ejecting ink from the nozzles of the inkjet head based on the number of drops of the drop data.

When ink is ejected from the nozzles of an inkjet head, ink (hereinafter referred to as ink mist) that is different from the main droplet of ink for printing an image is generated due to various effects such as ink ejection speed and ink viscosity. .

The generated ink mist floats under the ink jet head and may adhere to the ink jet head and peripheral members of the ink jet head when left for a long time.

On the other hand, an inkjet printing apparatus such as that disclosed in Patent Document 1 is a system in which suction means is provided under a conveying belt having a vent hole and the sheet on the conveying belt is conveyed while being sucked. In this way, when the paper on the transport belt is transported while being sucked, the ink floating under the inkjet head when the paper interval between the paper existing on the transport belt overlaps with the vent hole The mist can be sucked by the suction means to prevent ink from adhering to the inkjet head and the peripheral members of the inkjet head.

By the way, in order to increase the productivity of printing in recent ink jet printing apparatuses, a means is adopted in which the paper interval on the conveyor belt is narrowed and conveyed. Also in Patent Document 1, in order to increase the productivity of printing, it is assumed to take a means of transporting paper with a narrower interval.

JP 2009-13329 A

However, in the ink jet printing apparatus such as Patent Document 1, when the paper interval is narrowed and transported, the productivity of printing increases. On the other hand, the area where the air hole of the transport belt overlaps the paper interval is reduced, Accordingly, the amount of ink mist sucked is reduced, and ink adhesion to the ink jet head and members around the ink jet head is likely to occur.

For this reason, there is a problem that ink adhering to the ink jet head and the peripheral member of the ink jet head hangs down from the member (hereinafter referred to as liquid dripping) and soils the conveyed paper.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce paper contamination due to ink dripping caused by ink mist adhesion even when the interval of conveyed paper is narrowed while increasing printing productivity.

According to the first feature of the ink jet printing apparatus according to the present invention, the ink jet head ejects ink from the nozzles on the ejection surface based on the image data, and the main scanning direction which is a direction orthogonal to the paper transport direction. A sheet is conveyed at a plurality of intervals in the sub-scanning direction by a head holder having a head group in which a plurality of head arrays composed of the inkjet heads are arranged in parallel and a suction means under a conveying belt having a vent hole. A transport unit, an ink mist recovery unit that is provided above the transport belt and that forms an air flow exhausted from the head holder and recovers ink mist, and a control that controls the operation of the ink mist recovery unit And the control unit is formed by the operation of the ink mist collection unit in accordance with the interval between sheets conveyed by the conveyance unit. To control the flow rate of the flow.

According to the second feature of the ink jet printing apparatus according to the present invention, the acquisition unit that acquires the drop number of the ink drop data according to the image data, and the control unit, the acquisition unit acquired by the acquisition unit When the number of drops is larger than a predetermined threshold, the air volume of the ink mist collection unit is increased.

According to the third feature of the ink jet printing apparatus according to the present invention, an air supply unit that further forms an air flow for supplying air into the head holder at one end of the head holder in the main scanning direction or the sub scanning direction. The ink mist collecting unit is provided at the other end of the head holder, and the control unit is configured to provide a nozzle of the inkjet head that discharges the number of drops determined to be larger than the predetermined threshold. When it is determined that the ink mist collection unit is disposed closer to the air supply unit than the ink mist collection unit, the ink mist collection unit and the air supply unit are operated.

According to the first feature of the ink jet printing apparatus according to the present invention, an ink mist collecting unit is provided above the conveying belt, and when the paper interval on the conveying belt is narrowed, the ink mist collecting unit causes the ink mist collecting unit to move below the ink jet head. Collect the floating ink mist. For example, control is performed to increase the air volume of the air flow formed by the operation of the ink mist collecting unit as the paper interval on the conveyor belt becomes narrower. In this way, even if the ink mist is sucked only by the suction fan under the conveyor belt, it is difficult to suck the ink mist by the ink mist collecting means. Since ink does not adhere, it is possible to prevent the conveyed paper from being soiled by dripping.

Further, according to the second feature of the ink jet printing apparatus according to the present invention, the ink jet printing apparatus further includes an acquisition unit that acquires the number of ink drops, and when it is determined that the condition is such that more ink mist is generated than the acquired number of drops, The amount of air generated by the operation of the ink mist collecting unit, not the suction fan under the transport belt, is increased. By doing so, it is possible to efficiently collect ink mist while transporting the paper stably.

Furthermore, according to the third feature of the ink jet printing apparatus according to the present invention, the nozzle of the ink jet head that further includes an air supply unit and satisfies the condition that a lot of ink mist is generated is not the ink mist collecting unit but near the air supply unit. In this case, the ink mist collecting unit and the air supply unit are operated. By doing in this way, the ink mist which generate | occur | produced many on the air supply part side can be efficiently collect | recovered by the ink mist collection | recovery part.

1 is an overall view of an inkjet printing apparatus. It is a block diagram of a control part. It is a top view of an inkjet unit. This is a flow from receiving a print job to printing. (A) It is a figure when a sheet | seat does not exist on the ventilation hole of a conveyance belt. (B) It is a figure when a sheet | seat exists on the ventilation hole of a conveyance belt. FIG. 6 is a diagram defining a sheet interval on a conveyance belt. It is a figure at the time of providing an air supply part.

<Example 1>
Embodiments of the present invention will be described below with reference to the drawings.

Hereinafter, the entire inkjet printing apparatus will be described with reference to FIG.

As shown in FIG. 1, the inkjet printing apparatus 1 includes a side paper feed unit 10, an internal paper feed unit 20, a printing unit 30, a paper discharge unit 40, and a reversing unit 50.

The side paper feeder 10 includes a paper feeder 11 on which paper P is stacked, a primary paper feeder 12 that conveys only the uppermost paper P from the paper feeder 11 onto the paper feed conveyance path FR, And a secondary paper feeding unit 14 for carrying the paper P conveyed by the primary paper feeding unit 12 onto the circulation conveyance path CR.

The internal paper feeder 20 includes a paper feeder 21a on which the paper P is stacked, a primary paper feeder 22a that conveys only the uppermost paper P from the paper feeder 21a onto the paper feed conveyance path FR, and paper A sheet feeding table 21A on which P is stacked, a primary sheet feeding unit 22A for conveying only the uppermost sheet P from the sheet feeding table 21A onto the sheet feeding conveyance path FR, and a sheet feeding table on which the sheet P is stacked. 21c, a primary paper supply unit 22c that conveys only the uppermost paper P from the paper supply table 21c onto the paper supply conveyance path FR, a paper supply table 21d on which the paper P is stacked, and the paper supply table 21d. And a primary paper feed unit 22d for transporting only the uppermost sheet P onto the paper feed transport path FR.

As described above, the paper P is transported to the secondary paper feeder 14 from the side paper feeder 10 and the internal paper feeder 20, and further, the paper P is transported from the reversing unit 50 described later.

Therefore, in front of the secondary paper feeding unit 14 in the transport direction, the transport path of the fed paper P and the path through which the paper P printed on one side is circulated and merged join A point exists. Based on this merging point, the path on the paper feed mechanism side is referred to as a paper feed conveyance path FR, and the other path is referred to as a circulation conveyance path CR.

The printing unit 30 includes an inkjet head unit 31 in which a plurality of inkjet heads are incorporated, and a discharge mechanism that moves the inkjet head unit 31 and the like. The inkjet head unit 31 includes a plurality of line-type inkjet heads 110 to 116 arranged in a plurality of lines in the main scanning direction, that is, the direction orthogonal to the conveyance direction of the paper P. The inkjet heads 110 to 116 have a plurality of nozzle rows on the ink ejection surface, and eject ink from each nozzle.

The paper P fed by the secondary paper feed unit 14 is placed on the transport belt 133 by belt suction fans 131 and 132 installed in the annular transport belt 133 and corresponding to the back surface of the transport path surface of the paper P. The ink is sucked by the ink, transported at a predetermined transport speed, and printed by the ink ejected from the inkjet heads 110 to 116.

The belt suction fans 131 and 132 convey the paper P on the conveyance belt 133 while the air volume is adjusted by the control unit 80.

The paper P printed by the printing unit 30 is conveyed on the circulation conveyance path CR in the housing by a conveyance roller or the like disposed on the circulation conveyance path CR. On the circulation conveyance path CR, a switching mechanism 43 that switches between guiding the paper P conveyed on the circulation conveyance path CR to the paper discharge unit 40 or recirculating on the circulation conveyance path CR is provided. .

The switching mechanism 43 switches the paper P in order to guide the paper P to one of a paper discharge unit 40 and a reversing unit 50 described later.

The paper discharge unit 40 includes a tray-shaped paper discharge table 41 protruding from the casing of the inkjet printing apparatus 1 and a pair of paper discharge rollers 42 that guide the paper P to the paper discharge table 41. Then, the paper P guided to the paper discharge unit 40 by the switching mechanism 43 is transported to the paper discharge table 41 by the paper discharge roller 42 and stacked on the paper discharge table 41 with the printing surface down.

The reversing unit 50 includes a reversing table 51 for reversing the paper P, and a reversing roller 52 that transports the paper P from the circulation conveyance path CR to the reversing table 51 or conveys the paper P from the reversing table 51 onto the circulation conveyance path CR It has.

The sheet P guided to the reversing unit 50 by the switching mechanism 43 is transported from the circulation transport path CR to the reversing table 51 by the reversing roller 52, and is transported from the reversing table 51 to the circulation transport path CR after a predetermined time. The front and back are reversed with respect to the circulation conveyance path CR. The sheet P with the front and back reversed is conveyed toward the printing unit 30 on the circulation conveyance path CR by a plurality of rollers such as a conveyance roller 53 provided on the circulation conveyance path CR.

The transport unit 60 includes the side paper feed unit 10, the internal paper feed unit 20, the paper discharge unit 40, the reversing unit 50, and the transport belt 133. The transport unit 60 generates a transport schedule so as to maintain the paper interval L, and transports the paper P on the transport belt 133. Similarly, the conveyance unit 60 maintains the sheet interval L of any of a plurality of predetermined sheet intervals L in the side sheet supply unit 10, the internal sheet supply unit 20, the sheet discharge unit 40, and the reversing unit 50. A conveyance schedule is generated and the paper P is conveyed.

Hereinafter, the configuration of the control unit will be described with reference to FIG.

As shown in FIG. 2, the inkjet printing apparatus 1 includes a side paper feed unit 10, an internal paper feed unit 20, a printing unit 30, a paper discharge unit 40, a reversing unit 50, a transport unit 60, and an operation panel. Unit 70, control unit 80, acquisition unit 90, and image processing unit 100. Among these configurations, the side paper feed unit 10, the internal paper feed unit 20, the printing unit 30, the paper discharge unit 40, the reversing unit 50, and the transport unit 60 have been described above, and thus description thereof is omitted. To do.

The operation panel unit 70 is provided in the inkjet printing apparatus 1 and displays print settings and the like on the panel so that the user can make print settings. The print settings here are a print speed priority mode, print density, color mode, and the like. In addition, when the printing speed priority mode in which the printing speed is higher than the normal printing speed is selected by the conveyance unit 60, the paper is conveyed at a paper interval L2 that is narrower than the paper interval L1 of normal paper conveyance. Set.

The control unit 80 includes a CPU 81, a ROM 82 storing operation programs and various tables of the CPU 81, image data read by an image reading unit (not shown), or image data transmitted from a computer device (not shown). Furthermore, it has a RAM 83 for storing a print job including various printing conditions from the operation panel unit 70 or a computer device (not shown).

As shown in FIG. 2, the CPU 81 executes the operation program stored in the ROM 82, whereby the entire apparatus, that is, the side paper feeding unit 10, the internal paper feeding unit 20, the printing unit 30, and the paper ejection unit. 40, the reversing unit 50, the transport unit 60, the operation panel unit 70, the acquisition unit 90, and the image processing unit 100 are controlled.

The predetermined threshold value set here is regarded as a large amount of ink mist generated when the number of drops acquired by the acquisition unit 90 exceeds the predetermined threshold value. That is, the ink mist amount tends to increase as the number of drops increases. For example, when an inkjet head is capable of ejecting ink from 0 to 7 drops from a nozzle, ink mist is allowed at 0 to 4 drops, and a lot of ink mist is generated at 5 to 7 drops. Tend to be unacceptable.

Therefore, the CPU 81 causes the ink mist collection units 150 to 156 to collect the ink mist floating under the inkjet head when the number of drops acquired by the acquisition unit 90 exceeds a predetermined threshold. The mist collection | recovery parts 150-156 are controlled. In the present embodiment, the predetermined threshold is set to 5 drops or more as the number of drops that adversely affect the print image.

The acquisition unit 90 is a communication interface that receives a print job from an information terminal device such as a PC, and acquires print settings input from the operation panel unit 70. The acquisition unit 90 passes image data included in the received print job to the control unit 80. Then, the control unit 80 delivers the image data to the image processing unit 100.

The image processing unit 100 performs image processing on the image data received from the acquisition unit 90. For example, image processing such as RIP processing or RGB-CMYK conversion processing is performed. Further, the image processing unit 100 calculates the amount of ink ejected from the printing unit 30 based on each color component value. The control unit 80 passes the image data processed by the image processing unit 100 to the printing unit 30 and causes it to be printed.

Based on the print job received by the acquisition unit 90, the RIP process is developed into a bitmap with a predetermined resolution of a red (hereinafter, R) component, a green (hereinafter, G) component, and a blue (hereinafter, B) component. Image data that is the resulting raster data is generated. Here, in the image data, the R component value (for example, 0 to 255), the G component value (for example, 0 to 255), and the B component value (for example, for each pixel developed at a predetermined resolution). , 0-255).

The RGB-CMYK conversion unit processing uses R, G, and B component image data generated by RIP processing, using a lookup table, a cyan (hereinafter referred to as C) component, a magenta (hereinafter referred to as M) component, yellow (Hereinafter referred to as Y) component and black (hereinafter referred to as K) component are converted into image data.

Further, the image processing unit 100 generates drop data in which the number of drops ejected from the inkjet heads 110 to 116 is calculated based on the CMYK component values. Then, the acquisition unit 90 acquires the drop data generated by the image processing unit 100.

Hereinafter, the plane of the inkjet head unit will be described with reference to FIG.

As shown in FIG. 3, the inkjet head unit 31 includes a plurality of line-type inkjet heads 110 to 116 and a head holder 32 arranged in a plurality of lines in the main scanning direction, that is, a direction orthogonal to the transport direction of the paper P. .

The paper P is conveyed from the nozzles on the ejection surfaces of the plurality of inkjet heads 110 to 116 while being conveyed by the conveyance belt 133 in the sub-scanning direction, which is a direction perpendicular to the main scanning direction, immediately below the inkjet head unit 31. An image is printed by ejecting.

The inkjet head unit 31 includes a head group including inkjet heads 110 to 116 of each color of black (K), cyan (C), magenta (M), and yellow (Y) in a head holder 32 having a rectangular parallelepiped shape. Specifically, inkjet heads 110a to 110f storing black (K) ink, inkjet heads 110a to 112f storing cyan (C) ink, and inkjet heads 110a to 110f storing magenta (M) ink. 114 f and inkjet heads 110 a to 116 f storing yellow (Y) ink are fixed to the head holder 32.

The inkjet heads 110a, 110c, and 110e are arranged in one row in the main scanning direction as the head row 110A, and the inkjet heads 110b, 110d, and 110f are arranged in one row in the main scanning direction as the head row 110B. The inkjet heads 110a, 110c, and 110e of the head row 110A and the inkjet heads 110b, 110d, and 110f of the head row 110B can discharge cyan (C) ink without any gap in the main scanning direction of the paper P being conveyed. In order to make it possible, they are arranged in a staggered pattern in the sub-scanning direction. Similarly to the inkjet head 110, head rows 112A and 112B are formed on the inkjet head 112, head rows 114A and 114B are formed on the inkjet head 114, and head rows 116A and 116B are formed on the inkjet head 116. Is formed. A head group is formed by a set of such ink jet heads 110 to 116.

During printing, various colors are formed by discharging these inks on the same pixel. The ink jet heads 110 to 116 are supplied with ink from an ink cartridge having an ink tank via an ink supply path (both not shown).

In addition to the inkjet heads 110 to 116, the head holder 32 is provided with an ink mist collection unit 150 that collects ink mist by generating an air flow exhausted from the head holder 32 corresponding to the inkjet heads 110 to 116. Mainly, the ink mist collection units 150 to 156 collect an ink mist by generating an air flow under the head group.

As described above, the ink mist collecting units 150 to 156 provided at one end of the head holder 32 operate, thereby forming an air flow under the head holder 32, and ink generated by ejection from the inkjet heads 110 to 116. Mist can be recovered.

Hereinafter, a flow from reception of a print job to printing will be described with reference to FIG.

The acquisition unit 90 of the inkjet printing apparatus 1 receives a print job (S100).

The acquisition unit 90 acquires image data from the print job acquired by the acquisition unit 90 (S102). Then, the acquisition unit 90 delivers the image data to the image processing unit 100, performs image processing on the image data acquired by the image processing unit 100, and generates drop data.

The acquisition unit 90 acquires the number of drops of drop data corresponding to the image data generated by the image processing unit 100 (S104). The drop data is data representing the number of drops based on CMYK component values for ejection from each nozzle of the inkjet heads 110 to 116.

The control unit 80 determines whether the printing speed priority mode is selected by the operation panel unit 70 (S106). When it is determined that the printing speed priority mode is selected by the operation panel unit 70 (S106: YES), the control unit 80 sets the sheet interval to L2 (S108) and causes the conveyance unit 60 to convey the sheet P. .

The control unit 80 starts the operation of the ink mist collection units 150 to 156 when the conveyance unit 60 conveys the paper P at L2. In this case, the control unit 80 causes the ink mist collection units 150 to 156 to operate as described later.

The control unit 80 is formed by the operation of the ink mist collection units 150 to 156 because a large amount of ink mist is generated when the number of drops of the drop data acquired by the acquisition unit 90 is greater than or equal to a predetermined threshold (S112: YES). The ink mist collecting units 150 to 156 are operated in the “strong mode” so as to increase the air volume to be increased (S114). As a result, a larger air flow is generated than when the ink mist collection units 150 to 156 operate in the “normal mode”, and the ink mist collection under the head holder 32 by the ink mist collection units 150 to 156 is performed in the “normal mode”. Can be more.

The inkjet heads 110 to 116 of the inkjet printing apparatus 1 discharge and print based on the number of drops of the drop data acquired by the acquisition unit 90 (S116). In this case, the operation of the ink mist collecting units 150 to 156 is in a state that continues until the printing of the print job is completed.

In S106, when the control unit 80 determines that the print speed priority mode is not selected by the operation panel unit 70 (S106: NO), the sheet interval is set to L1 (S118), and the sheet P is transferred to the transport unit 60. Transport. Thereafter, the process proceeds to S116 for printing.

In S112, the control unit 80 operates the ink mist collection units 150 to 156 in a normal operation when the number of drops of the drop data acquired by the acquisition unit 90 is equal to or less than a predetermined threshold (S112: NO) (S120).

FIG. 5A is a diagram when the sheet P does not exist on the ventilation holes of the conveyance belt. Hereinafter, the inkjet head unit 31 when the paper P does not exist on the vent holes of the transport belt will be described with reference to FIG.

As shown in FIG. 5A, suction fans 131 and 132 are provided below the transport belt 133 having the air holes.

As shown in FIG. 5A, in the state where the paper P does not exist on the conveying belt 133 having the air holes, the air holes are not blocked by the paper P. The ink mist floating in step S is sucked by the suction fans 131 and 132 so that the ink mist does not adhere to the ink jet head 110 on the paper P. This is to prevent so-called dripping from the ink-adhered member when the ink mist adheres to the ink-jet head 110 or the peripheral member of the ink-jet head 110.

FIG. 5B is a diagram when the paper P is present on the vent hole of the transport belt. Hereinafter, the inkjet head unit 31 when the paper P is present on the air hole of the transport belt will be described with reference to FIG.

On the other hand, as shown in FIG. 5B, when the paper P is present on the transport belt 133 having the air holes, the paper P is sucked by the suction fans 131 and 132 and the ink jet head 110 of the ink jet head unit 31. Transported under. Although not shown, the paper P is also transported under the inkjet heads 112 to 116 as in the inkjet head 110.

On the paper P transported on the transport belt 133, ink ejected by the ink jet head 110 is landed and an image is formed (printed). In this case, main droplets and ink mist are generated by ejecting ink from the inkjet head 110. The main droplet is ink for forming an image.

An ink mist collection unit 150 provided above the transport belt 133 collects ink mist generated by ejecting ink with the inkjet head 110. The ink mist collecting unit 150 collects the ink mist by generating an air flow under the ink jet head 110 of the ink jet head unit 31 and forming an air flow from the ink jet head 110 toward the ink mist collecting unit 150. .

Hereinafter, the sheet interval on the conveyor belt will be described with reference to FIG.

As shown in FIG. 6, when there are a plurality of sheets P under the inkjet heads 110 </ b> A and 110 </ b> B of the inkjet head unit 31 and on the conveying belt 133 having the air holes, the sheet interval L between the sheets P and P is determined. The sheet P is transported on the transport belt 133 while maintaining the above.

Although not shown, while the paper interval L and the air holes overlap, the suction fans 131 and 132 under the transport belt 133 suck the ink mist under the inkjet heads 110A and 110B. Specifically, when the paper P is transported at the paper interval L1 for normal paper transport, the suction fans 131 and 132 under the transport belt 133 suck the ink mist under the inkjet heads 110A and 110B.

On the other hand, when the paper P is transported at a paper interval L2 that is narrower than the paper interval L1 for normal paper transport, even if the paper space L and the vent hole overlap, an ink mist collecting unit provided above the transport belt 133 150 operates to collect ink mist.

<Example 2>
As shown in FIG. 7, the inkjet printing apparatus 1 according to the second embodiment further includes air supply units 160 to 166. The rest of the configuration is the same as in the first embodiment, and a description thereof will be omitted. The head holder 32 includes air supply units 160 to 166 at one end of the head holder 32 in the main scanning direction, that is, a direction orthogonal to the conveyance direction of the paper P, and generates an air flow to be supplied into the head holder 32.

The ink mist collection units 150 to 156 are provided at the other end opposite to one end of the head holder 32.

When the transport unit 60 transports the paper P at L2, the control unit 80 starts the operation of the air supply units 160 to 166 in addition to the ink mist collection units 150 to 156 depending on the situation. Since the operations of the ink mist collection units 150 to 156 are the same as those in the first embodiment, a description thereof will be omitted.

When the control unit 80 starts the operation of the ink mist collection units 150 to 156, the number of drops determined to be greater than the predetermined threshold when the number of drops of the drop data acquired by the acquisition unit 90 is equal to or greater than the predetermined threshold. If it is determined that the nozzle of the inkjet head that discharges the ink is disposed closer to the air supply unit 160 to 166 than the ink mist collection unit 150 to 156, the air supply unit 160 to 166 is added to the ink mist collection unit 150 to 156. Also work.

Specifically, when attention is paid to the inkjet heads 110a, 110b, 110c, and 110d, the control unit 80 is determined to be larger than the predetermined threshold when the number of drops of the drop data acquired by the acquisition unit 90 is equal to or greater than a predetermined threshold. When the nozzles of the inkjet head that discharges the number of drops are nozzles of the inkjet heads 110a, 110b, and 110c, since the nozzles are arranged near the air supply unit 160, the air supply unit 160 also operates in addition to the ink mist collection unit 150 Let In this case, the air supply units 162 to 166 are also operated in conjunction with the operation of the air supply unit 160. Similarly, in conjunction with the operation of the ink mist collection unit 150, the ink mist collection units 152 to 156 are also operated.

On the other hand, when focusing on the inkjet head 110d, the control unit 80 ejects the number of drops determined to be greater than the predetermined threshold when the number of drops of the drop data acquired by the acquisition unit 90 is equal to or greater than the predetermined threshold. It is determined whether the nozzle of the head is close to the ink mist collection unit 150 or the air supply unit 160.

When the control unit 80 determines that the nozzle of the inkjet head that discharges the number of drops determined to be greater than the predetermined threshold is close to the ink mist collection unit 150, the control unit 80 operates the ink mist collection unit 150. In this case, in conjunction with the operation of the ink mist collection unit 150, the ink mist collection units 152 to 156 are also operated.

On the other hand, when the control unit 80 determines that the nozzle of the inkjet head that discharges the number of drops determined to be greater than the predetermined threshold is close to the air supply unit 160, the control unit 80 operates the ink mist collection unit 150 and the air supply unit 160. . In this case, the air supply units 162 to 166 are also operated in conjunction with the operation of the air supply unit 160. Similarly, in conjunction with the operation of the ink mist collection unit 150, the ink mist collection units 152 to 156 are also operated. By doing in this way, the ink mist collection | recovery in the ink mist collection | recovery part 150 can be performed efficiently, conveying the paper P on the conveyance belt 133 stably.

In the present embodiment, the ink mist collection units 150 to 156 are provided in the head holder 32. However, the present invention is not limited to this, and the ink mist collection units 150 to 156 may not be provided in the head holder 32 as long as they are provided above the transport belt 133. In this embodiment, the air supply units 160 to 166 and the ink mist collection units 150 to 156 are provided in the main scanning direction, that is, the direction orthogonal to the conveyance direction of the paper P, but may be provided in the sub-scanning direction. Good.

In this embodiment, the print speed priority mode is set by the operation panel unit 70, but may be included in the print settings of the print job regardless of the operation panel unit 70. Further, the sheet interval L may be changed for each job or may be changed for each page. Accordingly, the operations of the ink mist collecting units 150 to 156 or the air supply units 160 to 166 may be varied for each job or may be varied for each page.

In the present embodiment, the ink mist collection units 150 to 156 are provided for each of the inkjet heads 110 to 116, but may be provided for each of the head arrays 110A to 116B or for each head. In this embodiment, the ink mist collecting units 150 to 156 are operated when the paper interval L2 is set. However, the ink mist collecting units 150 to 156 are decreased as the paper interval L2 is reduced, that is, as the paper interval is reduced. You may make it increase the air volume formed by this operation | movement.

As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 10 ... Side paper feeding part 20 ... Internal paper feeding part 30 ... Printing part 31 ... Inkjet head unit 32 ... Head holder 40 ... Paper discharge part 50 ... Reversing part 60 ... Conveying part 70 ... Operation panel part 80 ... Control unit 81 ... CPU
82 ... ROM
83 ... RAM
DESCRIPTION OF SYMBOLS 90 ... Acquisition part 100 ... Image processing part 110 ... Inkjet head 131,132 ... Belt suction fan 133 ... Conveyance belt 150,152,154,156 ... Ink mist collection | recovery part

Claims (3)

An inkjet head that ejects ink from nozzles on the ejection surface based on image data;
A head holder having a head group in which a plurality of head arrays composed of the inkjet heads are arranged so as to be parallel to a main scanning direction which is a direction orthogonal to a paper transport direction;
A transport unit that transports the paper at a plurality of paper intervals in the sub-scanning direction by suction means under the transport belt having the air holes;
An ink mist collecting section that is provided facing the upper side of the conveyor belt and collects ink mist by forming an air flow exhausted from the head holder;
A control unit for controlling the operation of the ink mist collection unit,
The ink jet printing apparatus, wherein the control unit controls an air volume of an air flow formed by an operation of the ink mist collecting unit according to a paper interval conveyed by the conveying unit. Furthermore, an acquisition unit that acquires the number of drops of ink drop data according to the image data;
2. The inkjet printing apparatus according to claim 1, wherein when the number of drops acquired by the acquisition unit is greater than a predetermined threshold, the control unit increases the air volume of the ink mist collection unit. Furthermore, an air supply unit for forming an air flow to be supplied into the head holder is provided at one end of the head holder in the main scanning direction or the sub-scanning direction,
The ink mist collection unit is provided at the other end of the head holder,
When the control unit determines that the nozzle of the inkjet head that discharges the number of drops determined to be greater than the predetermined threshold is disposed closer to the air supply unit than the ink mist collection unit, The ink jet printing apparatus according to claim 2, wherein an ink mist collecting unit and the air supply unit are operated.