JP2018069663A - Printer and adjustment method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of highly accurately correcting landing position deviations of ink droplets in a direction orthogonal to a conveyance direction of a printing medium.SOLUTION: A textile printing apparatus 100 comprises: a conveyor belt 23 conveying a fabric 1 in a conveyance direction; a printing section 40 performing printing by imparting ink droplets to the fabric 1 conveyed; and an apparatus control section 80 controlling positions where the ink droplets are imparted. The apparatus control section 80 corrects the positions where the ink droplets are imparted in a direction intersecting with the conveyance direction based on displacement characteristic data indicating a displacement amount in the direction intersecting with the conveyance direction of the conveyor belt 23 in association with movement in the conveyance direction of the conveyor belt 23.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a printing apparatus that performs printing on a belt-carrying print medium and a method for adjusting the printing apparatus.

  2. Description of the Related Art Conventionally, as a printing apparatus, for example, an ink jet printer that performs printing on a print medium conveyed by a conveyance belt, such as a textile printing apparatus that performs printing on a long cloth, is known. In such a printing apparatus, a technique for suppressing a decrease in print quality due to the conveyance accuracy (error) of the print medium by the conveyance belt has been studied. For example, Patent Document 1 discloses a conveyance belt that conveys a print medium (printing paper) in the conveyance direction (sub-scanning direction), and a line that is arranged so that nozzles extend along a main scanning direction orthogonal to the conveyance direction. There is described a printing apparatus (image forming apparatus) that includes a head and correction means that corrects the ejection timing of the ink droplets from the line head in association with the landing position deviation of the ink droplets associated with the rotation of the conveyor belt. . Further, for example, Patent Document 2 describes a printing apparatus including a meandering detecting unit that detects meandering of a conveyed printing medium (recording medium) and a control unit that performs meandering canceling processing for canceling the detected meandering. Has been.

JP 2014-69322 A Japanese Patent Laying-Open No. 2015-187035

However, the printing apparatus described in Patent Document 1 can correct the ink droplet landing position deviation in the conveyance direction (sub-scanning direction) accompanying conveyance, but the ink droplet landing position deviation in the main scanning direction orthogonal to the conveyance direction. There was a problem that it was not possible to correct.
Further, in the printing apparatus described in Patent Document 2, it is possible to suppress wrinkling of the printing medium by detecting the meandering of the printing medium and eliminating the meandering, but the conveyance direction (sub-scanning direction) and There is room for improvement in correcting the landing position deviation of the ink droplets in the orthogonal main scanning direction, for example, sufficient correction accuracy may not be obtained for the ink droplet size and pitch accuracy. .

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following application examples or forms.

  Application Example 1 A printing apparatus according to this application example includes a conveyance belt that conveys a print medium in a conveyance direction, a printing unit that performs printing by applying ink droplets to the conveyed print medium, and the ink droplets. A displacement characteristic indicating a displacement amount of the conveyance belt in a direction intersecting the conveyance direction as the conveyance belt moves in the conveyance direction. Based on the data, the position where the ink droplet is applied in a direction intersecting the transport direction is corrected.

  According to this application example, the control unit in the direction intersecting the transport direction based on the displacement characteristic data indicating the amount of displacement in the direction intersecting the transport direction of the transport belt accompanying the movement of the transport belt in the transport direction. The position where the ink droplet is applied is corrected. In other words, the position of the ink droplets applied to the print medium that is transported by the transport belt and whose position is displaced with the displacement of the transport belt intersects the transport direction of the transport belt as the transport belt moves in the transport direction. Correction is performed based on displacement characteristic data indicating the amount of displacement in the direction. As a result, it is possible to perform correction with respect to the displacement in the direction intersecting the conveyance direction of the conveyance belt with higher accuracy, and it is possible to more effectively suppress a decrease in print quality due to the displacement.

  Application Example 2 In the printing apparatus according to the application example described above, the control unit determines a reference position of the printing in a direction intersecting the transport direction based on the displacement characteristic data.

  According to this application example, the control unit in the direction intersecting the transport direction based on the displacement characteristic data indicating the amount of displacement in the direction intersecting the transport direction of the transport belt accompanying the movement of the transport belt in the transport direction. Determine the reference position for printing. As a result, printing on a print medium that is transported by the transport belt and whose position is displaced in accordance with the displacement of the transport belt can be performed at a more appropriate position.

  Application Example 3 In the printing apparatus according to the application example described above, the displacement characteristic data includes data for at least one period in which the displacement amount changes, and the control unit rotates the conveyor belt within the one period. Based on the amount of displacement obtained corresponding to the position, the position at which the ink droplet is applied in the direction intersecting the transport direction at the rounding position is corrected.

  According to this application example, the displacement characteristic data indicating the displacement amount in the direction intersecting the conveyance direction of the conveyance belt accompanying the movement of the conveyance belt in the conveyance direction includes data for at least one cycle in which the displacement amount changes. It is out. Further, the control unit corrects the position at which the ink droplet is applied in the direction intersecting the conveyance direction at the circumference position based on the displacement amount obtained corresponding to the circumference position of the conveyance belt within one cycle. That is, displacement position data (displacement characteristic data) in which the position of an ink droplet applied to a print medium that is transported by a transport belt and displaced in accordance with the displacement of the transport belt corresponds to the movement position of the transport belt in the transport direction Is corrected based on As a result, correction accompanying displacement in the direction intersecting the transport direction of the transport belt can be performed with higher accuracy, and deterioration in print quality can be suppressed.

  Application Example 4 In the printing apparatus according to the application example described above, an image processing unit that acquires the displacement characteristic data by performing image recognition and image processing on a predetermined pattern printed by the printing unit in order to measure the displacement amount. It is characterized by providing.

  According to this application example, the printing apparatus recognizes an image of a predetermined pattern printed by the printing unit in order to measure a displacement amount in a direction intersecting the conveyance direction of the conveyance belt as the conveyance belt moves in the conveyance direction. An image processing unit that acquires displacement characteristic data by performing image processing is provided. Therefore, for example, the user of the printing apparatus can update the displacement characteristic data so as to correspond to the latest state of the printing apparatus. As a result, correction accompanying displacement in the direction intersecting the transport direction of the transport belt can be performed with higher accuracy, and deterioration in print quality can be suppressed.

  Application Example 5 An adjustment method of a printing apparatus according to this application example includes a conveyance belt that conveys a print medium in a conveyance direction, a printing unit that performs printing by applying ink droplets to the conveyed print medium, and A method of adjusting a printing apparatus comprising: obtaining displacement characteristic data indicating a displacement amount of the conveyance belt in a direction intersecting the conveyance direction as the conveyance belt moves in the conveyance direction; And determining the rotation position of the conveyor belt for adjusting the printing device based on displacement characteristic data, and applying the ink droplets in the direction intersecting the conveyance direction at the determined rotation position It is characterized in that the position to be adjusted is adjusted.

  The adjustment method of the printing apparatus according to this application example includes a step of acquiring displacement characteristic data indicating a displacement amount in a direction intersecting the conveyance direction of the conveyance belt accompanying the movement of the conveyance belt in the conveyance direction, and the acquired displacement characteristic And a step of determining the rotation position of the conveying belt for adjusting the printing apparatus based on the data. Further, the position at which the ink droplets are applied in the direction intersecting the transport direction is adjusted at the rotation position determined here. In other words, the adjustment of the position for applying the ink droplets in the direction intersecting the transport direction is based on the displacement characteristic data indicating the amount of displacement in the direction intersecting the transport direction of the transport belt as the transport belt moves in the transport direction. Perform at the determined rounding position. Therefore, it is possible to adjust the position where the ink droplets are applied at a position where the displacement in the direction intersecting the conveyance direction of the conveyance belt is more stable, and thus it is possible to perform more appropriate adjustment. .

  Application Example 6 In the adjustment method of the printing apparatus according to the application example described above, based on the displacement characteristic data, a center value of a width at which the transport belt is displaced in a direction intersecting the transport direction is obtained, and the center value is obtained. The rotation position of the conveyance belt where the conveyance belt is located is determined as the rotation position of the conveyance belt for adjusting the printing apparatus.

  According to this application example, the adjustment of the position at which the ink droplets are applied in the direction intersecting the transport direction at the circumferential position of the transport belt where the transport belt is positioned at the center value of the width in which the transport belt is displaced in the direction intersecting the transport direction. Therefore, it is possible to adjust the position where the ink droplets are applied at a position where the displacement in the direction intersecting the transport direction of the transport belt is more stable, and more appropriate adjustment can be performed. It becomes possible.

  Application Example 7 In the method for adjusting a printing apparatus according to the application example described above, based on the displacement characteristic data, the most frequent position where the conveyance belt is most frequently located in a direction intersecting the conveyance direction is obtained. The rotation position of the conveyance belt at which the conveyance belt is positioned is determined as the rotation position of the conveyance belt for adjusting the printing apparatus.

  According to this application example, the position where ink droplets are applied in the direction intersecting the transport direction can be adjusted at the most frequent position where the transport belt is located most in the direction intersecting the transport direction. It is possible to perform an effective adjustment with a higher contribution ratio of time to be reflected.

Schematic showing a textile printing apparatus as a “printing apparatus” according to an embodiment Block diagram explaining functions of apparatus control unit and image processing apparatus Illustration of basic functions of the printer driver Schematic diagram showing an example of nozzle arrangement as seen from the bottom of the head Explanatory drawing which shows the example of the predetermined pattern for calculating | requiring displacement amount Graph showing an example of plotting displacement characteristics data of a conveyor belt A graph showing an example of plotting two periods of displacement characteristic data obtained by measurement

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention. In the following drawings, the scale may be different from the actual scale for easy understanding. Also, in the coordinates added to the drawings, the Z-axis direction is the vertical direction, the + Z direction is the upward direction, the X-axis direction is the front-rear direction, the -X direction is the front direction, the Y-axis direction is the left-right direction, and the + Y direction is the left direction. The XY plane is a horizontal plane.

(Embodiment)
<Basic configuration of printing device (printing device)>
FIG. 1 is a schematic diagram showing a textile printing apparatus 100 as a “printing apparatus” according to the present embodiment, and shows the textile printing apparatus 100 installed on the floor 9 from the front.
The textile printing apparatus 100 is an ink jet printing apparatus that prints the textile 1 by ejecting (applying) ink droplets onto the textile 1 as a “printing medium” to form an image. As the fabric 1, for example, a fabric such as cotton, silk, wool, chemical fiber, and mixed spinning is used.
The textile printing device 100 includes a fabric supply unit 10, a fabric transport unit 20, a fabric collection unit 30, a printing unit 40, a maintenance unit 50, a fabric pressing unit 60, a device control unit 80, an image processing device 90, and the like.

The cloth supply unit 10 accommodates the cloth 1 before ink is applied, that is, a desired image is not formed. The fabric supply unit 10 includes a shaft portion 11 and a bearing portion 12.
The shaft portion 11 supports the belt-like fabric 1 wound in a roll shape so as to be rotatable in the circumferential direction. The shaft portion 11 is detachably attached to the bearing portion 12.
The bearing unit 12 includes a rotation driving unit (not shown) that rotates the shaft unit 11 and rotatably supports the shaft unit 11. The rotation driving unit is controlled by the device control unit 80, and in the case of the fabric 1 that is easily stretched, the rotation driving unit rotates the shaft unit 11 in the feeding direction. Further, in the case of the fabric 1 that needs to be tensioned, control is performed to apply a load so as not to rotate.

  The fabric transport unit 20 transports the fabric 1 through a transport path from the fabric supply unit 10 through the printing unit 40 to the fabric collection unit 30. The fabric transport unit 20 includes transport rollers 21, 26, 28, a tension roller 22, a transport belt 23, a belt rotation roller 24, a belt driving roller 25, a drying unit 27, a belt guide 29, and the like.

  The conveyor belt 23 is formed in an endless shape and is hung on a belt rotating roller 24 and a belt driving roller 25. The conveyance belt 23 is held in a state where a predetermined tension is applied so that a portion between the belt rotation roller 24 and the belt driving roller 25 is parallel to the floor surface 9. An adhesive layer (not shown) that adheres the fabric 1 is provided on the surface (support surface 23 a) of the transport belt 23. The conveyor belt 23 supports the fabric 1 with a support surface 23a provided with an adhesive layer.

The belt rotation roller 24 and the belt drive roller 25 support the inner peripheral surface 23 b of the transport belt 23. In addition, the structure provided with the support part which supports the conveyance belt 23 from the internal peripheral surface 23b between the belt rotation roller 24 and the belt drive roller 25 may be sufficient.
In the transport path, the belt driving roller 25 is disposed on the downstream side of the belt rotating roller 24. The rotation of the belt driving roller 25 is controlled by the device control unit 80. The conveyance belt 23 is rotated by the rotation of the belt driving roller 25, and the belt rotation roller 24 is rotated with the rotation of the conveyance belt 23. By the rotation of the transport belt 23, the fabric 1 supported by the transport belt 23 (support surface 23a) is transported in the transport direction. That is, the direction from the belt rotation roller 24 toward the belt drive roller 25 is the transport direction.

The tension roller 22 is provided between the fabric supply unit 10 and the transport belt 23 in the transport path, and generates a predetermined tension on the fabric 1 between the transport belt 23 (the support surface 23a that adheres to the fabric 1). .
The conveyance roller 21 relays the fabric 1 between the fabric supply unit 10 and the tension roller 22.
The conveyance roller 26 relays the fabric 1 conveyed by the conveyance belt 23.
The drying unit 27 is provided between the transport roller 26 and the transport roller 28 and guides and dries the fabric 1 after the ink is applied. The conveyance roller 28 relays the fabric 1 guided by the drying unit 27 to the fabric collection unit 30.

  The belt guide 29 is a pair of flat guides provided so as to sandwich the conveyor belt 23 from both ends in the width direction of the conveyor belt 23 in an area (printing area) facing the printing unit 40 of the conveyor belt 23. In the printing region, the conveyance belt 23 is prevented from being displaced in a direction intersecting the conveyance direction.

The fabric collection unit 30 accommodates the fabric 1 that has been applied with ink and has been dried (that is, on which desired image formation (printing) has been performed). The fabric collection unit 30 includes a shaft portion 31 and a bearing portion 32.
The shaft portion 31 is provided so as to be rotatable in the circumferential direction in order to house the fabric 1 in a roll shape. The shaft portion 31 is detachably attached to the bearing portion 32.
The bearing portion 32 has a rotation drive portion (not shown) that drives the shaft portion 31 to rotate, and supports the shaft portion 31 rotatably. The rotation drive unit is controlled by the device control unit 80 and rotates the shaft unit 31 in the direction in which the fabric 1 is wound.

The printing unit 40 is controlled by the device control unit 80 and ejects ink droplets onto the fabric 1. The printing unit 40 includes a head 41, a head moving unit 42, and an ink supply unit (not shown). The head 41 includes an ejection surface 41a that ejects ink supplied from the ink supply unit as ink droplets. A plurality of nozzles 43 for discharging ink droplets are formed on the discharge surface 41a. In the printing region, the ejection surface 41 a is provided so as to face the fabric 1 conveyed by the conveyance belt 23.
The head moving unit 42 includes a carriage on which the head 41 is mounted, a guide shaft provided in a direction intersecting the conveyance direction of the fabric 1, a drive mechanism that moves the carriage along the guide shaft, and the like (not shown). The head 41 is moved in the width direction (X-axis direction) of the fabric 1 intersecting the transport direction.

FIG. 4 is a schematic diagram illustrating an example of the arrangement of the nozzles 43 as viewed from the lower surface of the head 41.
In the head 41, for example, four nozzle rows are formed by a plurality of nozzles 43 arranged along the transport direction (Y-axis direction) of the fabric 1, and inks of different colors for each nozzle row (for example, cyan: C, magenta: M, yellow: Y, black: K) are ejected. In the example shown in FIG. 4, each nozzle row is composed of 400 nozzles 43 of # 1 to # 400.

  The maintenance unit 50 (see FIG. 1) is controlled by the device control unit 80 and performs maintenance of the transport belt 23. The maintenance unit 50 includes a processing unit 51, a base unit 52, and the like. The processing unit 51 conveys, for example, a removal unit that removes foreign matters such as dust and lint attached to the conveyance belt 23, and an adhesion layer repair unit that repairs the adhesion layer when the adhesion layer of the conveyance belt 23 deteriorates. It has a mechanism for performing various processing on the belt 23 (not shown). The base 52 supports the processing unit 51 so as to be movable up and down.

  The fabric pressing unit 60 is installed on the upper side of the transport belt 23 on the upstream side of the transport path from the printing unit 40. The fabric pressing portion 60 presses the fabric 1 to the support surface 23a having the adhesive layer, and prevents the fabric 1 from separating (floating) from the transport belt 23.

FIG. 2 is a block diagram illustrating the functions of the device control unit 80 and the image processing device 90.
The image processing apparatus 90 includes an image control unit 91, an input unit 92, a display unit 93, a storage unit 94, and the like, and exchanges data with an external electronic device connected via a network or the like and printing performed by the textile printing apparatus 100. It performs job control, image processing related to printing, and the like. The image processing apparatus 90 is configured using a personal computer as a preferred example.
Software for operating the image processing apparatus 90 includes general image processing application software (hereinafter referred to as an application) that handles image data to be printed, and printing necessary for the textile printing apparatus 100 to perform printing based on the image data. Includes printer driver software (hereinafter referred to as printer driver) that generates data.

The image control unit 91 includes a central processing unit (CPU) 95, an application specific integrated circuit (ASIC) 96, a digital signal processor (DSP) 97, a memory 98, an interface 99, and the like.
The input unit 92 is information input means as a human interface. Specifically, for example, a port to which a keyboard or an information input device is connected.
The display unit 93 is an information display unit (display) as a human interface, and information input from the input unit 92, information to be printed, information related to a print job, and the like are controlled under the control of the image control unit 91. Is displayed.
The storage unit 94 is a rewritable storage medium such as a hard disk drive (HDD) or a memory card. The storage unit 94 stores software (programs operating on the image control unit 91) that operates the image processing apparatus 90, images to be printed, and print jobs. Related information and the like are stored.
The memory 98 is a storage medium that secures an area for storing a program for the CPU 95 to operate, an operation area for the operation, and the like, and includes a storage element such as a RAM or an EEPROM.

The apparatus control unit 80 includes an interface 81, a CPU 82, a memory 83, a drive control unit 84, and the like, and comprehensively controls each drive unit of the textile printing apparatus 100. Specifically, the apparatus control unit 80 performs control of the printing unit 40 (ink ejection control with respect to the head 41 and head movement control with respect to the head moving unit 42), transport drive control with respect to the fabric transport unit 20, and the like.
At the time of printing, the apparatus control unit 80 mainly uses a carriage that supports the head 41 along the guide shaft for the fabric 1 supplied to the printing area by the fabric transport unit 20 according to the print data sent from the image processing apparatus 90. An operation of ejecting ink droplets from the head 41 while moving in the scanning direction (X-axis direction), and an operation of moving the fabric 1 in the transport direction (+ Y direction) intersecting the main scanning direction by the fabric transport unit 20 (transport belt 23). And repeat. By these operations, a desired image is formed (printed) on the fabric 1.

The interface 81 is connected to the image processing apparatus 90 (interface 99) and transmits / receives data to / from the image processing apparatus 90.
The CPU 82 is an arithmetic processing device for performing drive control of the entire textile printing apparatus 100.
The memory 83 is a storage medium that secures an area for storing a program for the CPU 82 to operate, a work area for the operation, and the like, and includes a storage element such as a RAM or an EEPROM.
The CPU 82 is connected to the fabric supply unit 10, the fabric transport unit 20, the fabric collection unit 30, and the printing unit 40 via the drive control unit 84 according to the program stored in the memory 83 and the print data received from the image processing apparatus 90. The maintenance unit 50 and the fabric pressing unit 60 are controlled.

<Basic functions of the printer driver>
FIG. 3 is an explanatory diagram of the basic functions of the printer driver.
Printing on the fabric 1 is started when print data is transmitted from the image processing apparatus 90 to the apparatus control unit 80 by the printer driver. The print data is generated by the printer driver.
The print data generation process will be described below with reference to FIG.

  The printer driver receives image data from the application, converts it into print data in a format that can be interpreted by the device control unit 80, and outputs the print data to the device control unit 80. When converting image data from an application into print data, the printer driver performs resolution conversion processing, color conversion processing, halftone processing, rasterization processing, command addition processing, and the like.

The resolution conversion process is a process of converting the image data output from the application into a resolution (printing resolution) when printing on the fabric 1. For example, when the print resolution is specified as 720 × 720 dpi, vector format image data received from the application is converted into bitmap format image data with a resolution of 720 × 720 dpi. Each pixel data of the image data after the resolution conversion process is composed of pixels arranged in a matrix. Each pixel has a gradation value of, for example, 256 gradations in the RGB color space. That is, the pixel data after resolution conversion indicates the gradation value of the corresponding pixel.
Pixel data corresponding to one column of pixels arranged in a predetermined direction among pixels arranged in a matrix is called raster data. The predetermined direction in which the pixels corresponding to the raster data are arranged corresponds to the moving direction (main scanning direction) of the head 41 when printing an image.

The color conversion process is a process for converting RGB data into data in the CMYK color system space. The CMYK colors are cyan (C), magenta (M), yellow (Y), and black (K), and the image data in the CMYK color system space is data corresponding to the ink color that the textile printing apparatus 100 has. . Therefore, for example, when the textile printing apparatus 100 uses 10 types of CMYK color inks, the printer driver generates CMYK color 10-dimensional space image data based on the RGB data.
This color conversion processing is performed based on a table (color conversion lookup table LUT) in which gradation values of RGB data and gradation values of CMYK color system data are associated with each other. Note that the pixel data after the color conversion processing is, for example, CMYK color system data of 256 gradations represented by the CMYK color system space.

  The halftone process is a process for converting high gradation number (256 gradations) data into gradation number data that can be formed by the textile printing apparatus 100. By this halftone processing, data indicating 256 gradations indicates, for example, 1-bit data indicating 2 gradations (with or without dots) or 4 gradations (without dots, small dots, medium dots, large dots). Converted to 2-bit data. Specifically, from the dot generation rate table corresponding to the gradation value (0 to 255) and the dot generation rate, the dot generation rate corresponding to the gradation value (for example, in the case of 4 gradations, no dot, small Pixel data is created so that dots are formed in a dispersed manner using the dither method, error diffusion method, etc. at the obtained generation rate. The

  The rasterizing process is a process of rearranging pixel data arranged in a matrix (for example, 1-bit or 2-bit data as described above) according to the dot formation order at the time of printing. The rasterizing process includes an allocating process for allocating image data composed of pixel data after halftone processing to each pass operation in which the head 41 (nozzle row) ejects ink droplets while scanning and moving. When the allocation process is completed, the pixel data arranged in a matrix is allocated to the actual nozzles forming each raster line constituting the print image.

The command addition process is a process for adding command data corresponding to the printing method to the rasterized data. The command data includes, for example, conveyance data related to the conveyance specifications (movement amount and speed in the conveyance direction) of the print medium (fabric 1).
These processes by the printer driver are performed by the ASIC 96 and the DSP 97 (see FIG. 2) under the control of the CPU 95, and the generated print data is transmitted to the apparatus control unit 80 via the interface 99 by the print data transmission process. Is done.

  In the textile printing apparatus 100 having the basic configuration described above, when the transport belt 23 is slightly displaced in the width direction (X-axis direction) of the fabric 1 that intersects the transport direction (Y-axis direction) in the printing region, it is accompanied accordingly. Accordingly, when the position of the fabric 1 in the X-axis direction is displaced, the landing position (dot position formed by the ink droplets) of the ink droplets ejected onto the fabric 1 is shifted, and the print quality constituted by a plurality of dots. (Image quality) sometimes deteriorated.

  The displacement in the width direction (X-axis direction) of the fabric 1 that intersects the transport direction (Y-axis direction) of the transport belt 23 is to guide the belt guide 29 so as to contact the end of the transport belt 23 in the width direction. , Large meandering is suppressed. However, for example, when there is a variation in the width of the conveyance belt 23 or when there are irregularities at the end in the width direction depending on the degree of processing of the conveyance belt 23, the conveyance belt 23 rotates with the rotation of the conveyance belt 23. The conveyor belt 23 may be slightly displaced due to the stress from the belt guide 29 that is in sliding contact with the belt 23. In addition to such factors, for example, due to eccentricity of the transport rollers 21, 26, 28, the tension roller 22, the transport belt 23, the belt rotation roller 24, the belt drive roller 25, and the like, variation in assembly accuracy, etc. The conveyor belt 23 may be slightly displaced.

Therefore, in the printing apparatus 100 of the present embodiment, the displacement amount in the direction intersecting the conveyance direction of the conveyance belt 23 accompanying the movement of the conveyance belt 23 in the conveyance direction is evaluated in advance as displacement characteristic data that the printing apparatus 100 has. Based on the displacement characteristic data, the apparatus control unit 80 can correct the position at which the ink droplet is applied in the direction intersecting the transport direction.
This will be specifically described below.

<Displacement characteristic data>
First, displacement characteristic data and its acquisition method will be described. The adjustment method of the textile printing apparatus 100 according to the present invention includes a step of acquiring the displacement characteristic data.
The amount of displacement by which the transport belt 23 is displaced in the direction intersecting the transport direction is such that a predetermined pattern is printed on a print medium (fabric 1 or print paper) placed on (supported by) the transport belt 23 and transported to the printing area. It is obtained by analyzing a predetermined printed pattern.

FIG. 5 is an explanatory diagram showing an example of a predetermined pattern for obtaining the displacement amount.
The predetermined pattern includes a landing pattern (dot row K shown in FIG. 5) by ink droplets ejected from a specific nozzle row provided in the head 41. The specific nozzle row is one of the nozzle rows constituted by a plurality of nozzles 43 (see FIG. 4) arranged along the transport direction, for example, nozzles that eject black ink (K). Is a column. Note that the dot row K as the predetermined pattern shown in FIG. 5 is shown as a ruled line made up of dot rows.

First, the conveyor belt 23 is stopped at the origin position of the conveyor system, and the head 41 is stopped at a predetermined position in the main scanning direction (X-axis direction) (for example, approximately the center position of the width of the conveyor belt 23). One-shot ink droplets are ejected to form the dot row K1. Next, the print medium is moved in the transport direction (+ Y direction) by a length D equivalent to that of the nozzle row, and one-shot ink droplets are again ejected from the nozzle row to form the dot row K2. Similarly, the movement of the printing medium and the ejection of ink droplets are repeated to print the dot row K as a predetermined pattern consisting of the dot rows K1 to Kn.
Here, the origin position of the transport system is a predetermined position in which the circumferential position of the transport belt 23 constituting the fabric transport unit 20 and the rotation position of each transport roller are specified, and may be any position that can be reproduced. . Information about the rotation position of the conveyance belt 23 and the rotation position of each conveyance roller is obtained by, for example, an encoder provided at various places.

  Next, the printing medium on which the predetermined pattern (dot row K) is printed is removed from the textile printing apparatus 100, and the amount of displacement in the main scanning direction (X-axis direction) of the dot rows K1 to Kn is measured. The method for measuring the amount of displacement is not particularly limited. For example, an image of a predetermined pattern (dot row K) is obtained as image data using a CCD (Charge Coupled Device) image sensor or the like, and is obtained by image processing. In the present embodiment, the displacement amount can be obtained by capturing a predetermined pattern (dot array K) as image data in the image processing apparatus 90 and performing image processing by the image control unit 91. In other words, the image processing device 90 has a function as an “image processing unit” that acquires the displacement characteristic data by recognizing a predetermined pattern printed by the printing unit 40 to measure the amount of displacement and performing image processing. Yes.

In addition, in order to be able to measure the displacement amount without removing the printing medium on which the predetermined pattern (dot row K) is printed from the textile printing apparatus 100, the textile printing apparatus 100 includes an image acquisition unit such as a CCD image sensor. Also good. In this case, the image acquisition unit is arranged at a position where the image of the printed predetermined pattern (dot row K) can be acquired, that is, downstream of the transport path of the fabric 1 with respect to the head 41. The image data acquired by the image acquisition unit is preferably configured to be transmitted to the image processing apparatus 90. In this case, the image processing apparatus 90 including the image acquisition unit functions as an “image processing unit”.
In this configuration, when acquiring an image of a predetermined pattern (dot row K), for example, the predetermined pattern (dot row) is prevented from being affected by the displacement in the direction intersecting the transport direction of the transport belt 23. It is preferable that a straight line serving as a reference (a reference line extending in the transport direction) is provided in advance on the print medium on which K) is printed. By doing so, the displacement amount can be obtained as a relative value with respect to the reference line in the X-axis direction.

As a method for obtaining the displacement amount by image processing from image data of a predetermined pattern (dot row K), for example, the position of the center of gravity P of each of the dot rows K1 to Kn (the center of gravity position of the dot row K3 is shown in FIG. 5). There is a method of obtaining the displacement amount in the X-axis direction. The displacement characteristic data is obtained as a value of a difference between the position (X value) of the center of gravity P of each dot row Kn with respect to the position (X value) of the center of gravity P of the dot row K1 at the reference position.
FIG. 6 is a graph showing an example in which the displacement characteristic data of the conveyor belt 23 obtained from the image data of the predetermined pattern (dot row K) in FIG. 5 is plotted. For example, as in the dot row K2 shown in FIG. 5, when the print position is shifted in the + X direction with respect to the dot row K1 at the reference position, the print medium (conveyance belt 23) is displaced in the -X direction. This means that the graph shown in FIG. 6 is a reverse plot with respect to FIG.

  The predetermined pattern is not limited to the above-described pattern. Any pattern may be used as long as the displacement amount in the direction intersecting the conveyance direction of the conveyance belt 23 can be acquired as the displacement characteristic data by the position of the conveyance system (fabric conveyance unit 20) (for example, the circumferential position of the conveyance belt 23). For example, ink droplets are ejected at a constant interval from a specific nozzle 43 that is moved to a substantially central position of the width of the conveyor belt 23 while the conveyor belt 23 circulates from the origin position of the conveyor system at a constant speed, and a continuous dot row. It may be a pattern obtained by forming.

When the displacement in the direction intersecting the conveyance direction of the conveyance belt 23 due to the movement of the conveyance belt 23 in the conveyance direction is caused by the unevenness of the end portion in the width direction of the conveyance belt 23, the period of the displacement characteristic data is If the other factors are combined, the cycle may become longer.
FIG. 7 is a graph showing an example in which two periods of displacement characteristic data obtained by measurement are plotted. When there are a plurality of main factors that cause the transport belt 23 to be displaced in the direction crossing the transport direction, the period T of the displacement characteristic data is longer than the rotation period of the transport belt 23.
In this way, when the displacement characteristic data is obtained as a characteristic having periodicity, it intersects with the conveyance direction based on the displacement characteristic data according to the conveyance amount from the origin position of the conveyance system regardless of the factor. By correcting the position where the ink droplets are applied in the direction in which printing is performed, it is possible to suppress a decrease in print quality. Further, by adjusting the textile printing apparatus 100 based on the width of displacement in the direction intersecting the conveyance direction of the conveyance belt 23 and the distribution of the displacement position, it is possible to suppress a decrease in print quality.
The adjustment method and correction method will be specifically described below.

<Determination of adjustment position of printing device (printing device)>
One of the adjustment contents of the printing apparatus 100 is adjustment of the ink droplet landing position in the main scanning direction (X-axis direction). This involves correction of the ink droplet landing position deviation accompanying the scanning movement of the head 41. First, the ink droplet landing position in the forward path of the scanning movement is determined as the target point, and then the ink droplet landing position in the backward path of the scanning movement. Adjust the position so that it matches the ink droplet landing position in the forward path (correction of misalignment).
The target point determines the position of the print area in the main scanning direction (X-axis direction). By determining the target point, the position of the pixel data arranged in a matrix of the print image on the cloth 1 on the X-axis is determined. It is determined. That is, when the position where the deviation of the ink droplet landing position in the forward and backward scanning movements is adjusted is moved on the X axis, the position of the printing area is also moved by the amount of movement.

  The adjustment method of the printing apparatus 100 according to the present embodiment includes a step of determining the rotation position of the transport belt 23 for adjusting the printing apparatus 100 based on the displacement characteristic data. Specifically, the rotation position of the conveyor belt 23 that determines the target point described above is determined based on the displacement characteristic data. More specifically, based on the displacement characteristic data, the center value of the width at which the transport belt 23 is displaced in the direction intersecting the transport direction is obtained, and the rotation position of the transport belt 23 at which the transport belt 23 is located at the center value, The target point is determined as the rotation position of the conveyor belt 23. For example, in the case of the example shown in FIG. 7, the widths (x1 to x3) in which the positions of y1, y2, and y3 are displaced in the direction intersecting the conveyance direction as the rotation positions of the conveyance belt 23 within the period T. Since the rotation position of the conveying belt 23 is located at the center value (x3) of the printing belt 100, adjustment of the printing apparatus 100 (determination of target point and correction of deviation of ink droplet landing position) is performed at any of these positions. Do.

The positions of y1, y2, and y3 can reproduce the amount of displacement in the direction intersecting the conveyance direction of the conveyance belt 23 when periodicity is recognized in the displacement characteristic data, that is, the position of the conveyance system (fabric conveyance unit 20). In this case, by referring to the displacement characteristic data, the position where x3 is given can be easily obtained.
For example, when the displacement characteristic data is obtained as a function f (m, n, l) with factors m, n, and l, a center value x3 is obtained from the minimum value x1 and the maximum value x2, and x3 is given. A method of deriving the position of the transport system (fabric transport unit 20) as m, n, and l may be used.

In the present embodiment, the displacement characteristic data obtained by the image processing apparatus 90 is stored in the memory 83 provided in the apparatus control unit 80. The apparatus control unit 80 determines a reference position for printing in a direction intersecting the transport direction based on the displacement characteristic data stored in the memory 83. Specifically, first, the device control unit 80 derives and derives the position of the conveyance system (fabric conveyance unit 20) that determines the target point (for example, the circumferential position of the conveyance belt 23) based on the displacement characteristic data. The conveyance system (fabric conveyance unit 20) is driven so as to be in the position. Next, the apparatus control unit 80 derives a target point (ink droplet landing position in the forward path of scanning movement) based on the displacement characteristic data, drives the head moving unit 42, and moves the head 41 to the target point. .
The operator of the textile printing apparatus 100 can adjust the ink droplet landing position on the return path of the scanning movement (correct the misalignment) so as to match the target point.

As described above, the target point defines a printing area in the main scanning direction (X-axis direction), and determining the target point corresponds to determining a printing reference position in a direction crossing the transport direction. .
In addition, since the target point defines a print area in the main scanning direction (X-axis direction), determining the target point based on the displacement characteristic data means that the conveyance is performed based on the displacement characteristic data. This corresponds to correcting the position where the ink droplet is applied in the direction intersecting the direction.

<Ink ejection position correction>
In the present embodiment, when the displacement characteristic data is obtained as characteristic data having periodicity, that is, when the displacement characteristic data includes data for at least one period in which the displacement amount changes, the device control unit 80 Based on the amount of displacement obtained corresponding to the rotation position of the conveyance belt 23 in one cycle, the position at which ink droplets are applied in the direction intersecting the conveyance direction at the rotation position is corrected.

  Specifically, for example, only a nozzle row that discharges black ink is used, and the feed pitch in the transport direction (Y-axis direction) is one transport by n passes at a pitch D from the reference position. When a straight line extending in the direction (Y-axis direction) is to be printed, when the conveyor belt 23 is displaced according to the displacement characteristic data as shown in FIG. 6, the printed straight line is shown in FIG. It becomes such a discontinuous straight line. Since the displacement amount corresponding to the rotation position of the conveyance belt 23 is known from the displacement characteristic data, the apparatus control unit 80 discharges ink droplets corresponding to the position of each pass (that is, the rotation position of the conveyance belt 23). By controlling the correction of timing, a discontinuous straight line can be printed as a straight line closer to a single straight line.

More specifically, the apparatus control unit 80 has an ink droplet ejection timing correction amount corresponding to the correction amount in the X-axis direction as a data table. By correcting the timing of driving the head 41 by the drive control unit 84 (see FIG. 2) by the correction amount corresponding to each pass, the position of the straight line to be printed can be corrected to an appropriate position.
Since the ink droplet ejection timing correction amount is simply calculated based on the carriage movement speed, real-time correction is performed so that the integral value of the ink droplet discharge coincides with the correction amount in the X-axis direction while detecting the carriage movement speed. May be performed.

As described above, according to the printing apparatus and the adjustment method of the printing apparatus according to the present embodiment, the following effects can be obtained.
The apparatus control unit 80 applies ink droplets in the direction intersecting the transport direction based on the displacement characteristic data indicating the displacement amount in the direction intersecting the transport direction of the transport belt 23 as the transport belt 23 moves in the transport direction. Correct the position to be applied. That is, the position of the ink droplet that is conveyed by the conveyor belt 23 and applied to the fabric 1 whose position is displaced with the displacement of the conveyor belt 23 is the conveyance of the conveyor belt 23 in accordance with the movement of the conveyor belt 23 in the conveyance direction. Correction is performed based on the displacement characteristic data indicating the amount of displacement in the direction intersecting the direction. As a result, it is possible to perform correction with respect to the displacement in the direction intersecting the conveyance direction of the conveyance belt 23 with higher accuracy, and it is possible to more effectively suppress a decrease in print quality due to the displacement.

  In addition, the apparatus control unit 80 performs printing in the direction intersecting the transport direction based on the displacement characteristic data indicating the displacement amount in the direction intersecting the transport direction of the transport belt 23 due to the movement of the transport belt 23 in the transport direction. Determine the reference position. As a result, printing on the fabric 1 that is transported by the transport belt 23 and whose position is displaced in accordance with the displacement of the transport belt 23 can be performed at a more appropriate position.

  Further, when the displacement characteristic data indicating the amount of displacement in the direction intersecting the conveyance direction of the conveyance belt 23 due to the movement of the conveyance belt 23 in the conveyance direction is obtained as the characteristic data having periodicity That is, when the displacement characteristic data includes data for at least one cycle in which the displacement amount changes, the device control unit 80 obtains the displacement amount obtained corresponding to the rotation position of the conveyor belt 23 within one cycle. Based on this, the position at which the ink droplets are applied in the direction intersecting the transport direction at the rounding position is corrected. That is, the position of the ink droplet applied to the fabric 1 that is transported by the transport belt 23 and is displaced along with the displacement of the transport belt 23 is the displacement amount data (displacement) corresponding to the movement position of the transport belt 23 in the transport direction. Is corrected based on the characteristic data. As a result, correction accompanying displacement in the direction intersecting the transport direction of the transport belt 23 can be performed with higher accuracy, and deterioration in print quality can be suppressed.

  Further, the textile printing apparatus 100 recognizes an image of a predetermined pattern printed by the printing unit 40 in order to measure the amount of displacement in the direction intersecting the transport direction of the transport belt 23 as the transport belt 23 moves in the transport direction, An image processing apparatus 90 is provided as an image processing unit that acquires displacement characteristic data by performing image processing. Therefore, for example, the user of the textile printing apparatus 100 can update the displacement characteristic data so as to correspond to the latest state of the textile printing apparatus 100. As a result, correction accompanying displacement in the direction intersecting the transport direction of the transport belt 23 can be performed with higher accuracy, and deterioration in print quality can be suppressed.

  Further, the adjustment method of the textile printing apparatus 100 according to the present embodiment includes a step of obtaining displacement characteristic data indicating a displacement amount in a direction intersecting the conveyance direction of the conveyance belt 23 due to the movement of the conveyance belt 23 in the conveyance direction; And a step of determining the rotation position of the conveyor belt 23 for adjusting the printing apparatus 100 based on the acquired displacement characteristic data. Further, the position at which the ink droplets are applied in the direction intersecting the transport direction is adjusted at the rotation position determined here. That is, the adjustment of the position at which the ink droplets are applied in the direction intersecting the transport direction is converted into displacement characteristic data indicating the amount of displacement in the direction intersecting the transport direction of the transport belt 23 as the transport belt 23 moves in the transport direction. It is performed at the round position determined based on the above. For this reason, it is possible to adjust the position where the ink droplets are applied at a position where the displacement in the direction intersecting the transport direction of the transport belt 23 is more stable, and thus more appropriate adjustment can be performed. Become.

  Further, the position at which the ink droplets are applied in the direction intersecting the transport direction is adjusted at the circumferential position of the transport belt 23 where the transport belt 23 is positioned at the center value of the width in which the transport belt 23 is displaced in the direction intersecting the transport direction. Therefore, it is possible to adjust the position where the ink droplets are applied at a position where the displacement in the direction intersecting the transport direction of the transport belt 23 is more stable, and more appropriate adjustment can be performed. It becomes.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the above-described embodiment. A modification will be described below. Here, the same components as those in the above-described embodiment are denoted by the same reference numerals, and redundant description is omitted.

(Modification 1)
In the above embodiment, the conveyor belt 23 in which the conveyor belt 23 is positioned at the center value of the width in which the conveyor belt 23 is displaced in the direction intersecting the conveyor direction is determined as the rotation position of the conveyor belt 23 that determines the target point in the adjustment of the printing apparatus 100. However, the present invention is not limited to this.
Based on the displacement characteristic data, the most frequent position where the conveyor belt 23 is located most in the direction intersecting the conveyance direction is obtained, and the rotation position of the conveyor belt 23 where the conveyor belt 23 is located at the most frequent position is determined by the printing apparatus 100. A method of determining the rotation position of the conveyance belt 23 to be adjusted may be used. According to this method, the position at which ink droplets are applied in the direction intersecting the transport direction can be adjusted at the most frequent position where the transport belt 23 is located most in the direction intersecting the transport direction. It is possible to perform an effective adjustment with a higher contribution ratio of time to be reflected.

(Modification 2)
In the above-described embodiment, the predetermined pattern printed by the printing unit 40 is recognized in order to measure the amount of displacement in the direction intersecting the transport direction of the transport belt 23 as the transport belt 23 moves in the transport direction, and image processing is performed. In this example, the image processing apparatus 90 has the function as the “image processing unit” for obtaining the displacement characteristic data. However, the textile printing apparatus 100 may not include the “image processing unit”.
For example, the manufacturer that manufactures the printing apparatus 100 acquires the displacement characteristic data of the transport belt 23 for each printing apparatus 100, stores the displacement characteristic data in the memory 83 or the storage unit 94, and provides the printing apparatus 100 to the user. It may be. In the use stage of the user, the apparatus control unit 80 can obtain the displacement characteristic data stored in the memory 83 or the storage unit 94, so that the same adjustment and correction as in the above embodiment can be performed.
Alternatively, when the textile printing apparatus 100 is maintained, means other than the image processing apparatus 90 are used by printing a predetermined pattern for obtaining the displacement characteristic data described in the above embodiment and analyzing the result. Alternatively, the displacement characteristic data may be generated.

  DESCRIPTION OF SYMBOLS 1 ... Fabric, 10 ... Fabric supply part, 11 ... Shaft part, 12 ... Bearing part, 20 ... Fabric conveyance part, 21 ... Conveyance roller, 22 ... Tension roller, 23 ... Conveyance belt, 23a ... Support surface, 23b ... Inner circumference 24, belt rotation roller, 25 ... belt drive roller, 26 ... transport roller, 27 ... drying unit, 28 ... transport roller, 29 ... belt guide, 30 ... fabric recovery section, 31 ... shaft section, 32 ... bearing section, DESCRIPTION OF SYMBOLS 40 ... Printing part, 41 ... Head, 41a ... Discharge surface, 42 ... Head moving part, 43 ... Nozzle, 50 ... Maintenance part, 51 ... Processing part, 52 ... Base part, 60 ... Fabric pressing part, 80 ... Apparatus control part , 81, interface, 82, CPU, 83, memory, 84, drive control unit, 90, image processing device, 91, image control unit, 92, input unit, 93, display unit, 94, storage unit, 95, C U, 96 ... ASIC, 97 ... DSP, 98 ... memory, 99 ... interface, 100 ... printing apparatus.

Claims (7)

A transport belt for transporting the print medium in the transport direction;
A printing unit that performs printing by applying ink droplets to the conveyed printing medium;
A controller for controlling a position to apply the ink droplets,
The controller in the direction intersecting the transport direction based on displacement characteristic data indicating a displacement amount of the transport belt in a direction intersecting the transport direction as the transport belt moves in the transport direction. A printing apparatus that corrects a position where an ink droplet is applied.   The printing apparatus according to claim 1, wherein the control unit determines a reference position for the printing in a direction intersecting the transport direction based on the displacement characteristic data. The displacement characteristic data includes data for at least one period in which the displacement amount changes,
A position at which the control unit applies the ink droplets in a direction intersecting the transport direction at the rotation position based on the displacement amount obtained corresponding to the rotation position of the transport belt within the one cycle. The printing apparatus according to claim 1, wherein correction is performed.   4. An image processing unit for acquiring the displacement characteristic data by recognizing a predetermined pattern printed by the printing unit to measure the amount of displacement and performing image processing. The printing apparatus as described in any one of. A transport belt for transporting the print medium in the transport direction;
A method for adjusting a printing apparatus comprising: a printing unit that performs printing by applying ink droplets to the conveyed printing medium,
Obtaining displacement characteristic data indicating a displacement amount of the transport belt in a direction intersecting the transport direction accompanying the movement of the transport belt in the transport direction;
Determining, based on the displacement characteristic data, a rotation position of the conveyor belt that performs adjustment of the printing apparatus,
A method for adjusting a printing apparatus, comprising: adjusting a position at which the ink droplet is applied in a direction intersecting the transport direction at the determined rounding position.   Based on the displacement characteristic data, a center value of a width in which the transport belt is displaced in a direction intersecting the transport direction is obtained, and the rotation position of the transport belt at which the transport belt is positioned is the center value. The method of adjusting a printing apparatus according to claim 5, wherein the rotation position of the conveying belt for performing the adjustment is determined.   Based on the displacement characteristic data, the most frequent position where the conveyor belt is located most in the direction intersecting the conveyance direction is obtained, and the rotation position of the conveyor belt where the conveyor belt is located at the most frequent position is 6. The method of adjusting a printing apparatus according to claim 5, wherein the rotation position of the conveying belt for adjusting the printing apparatus is determined.

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