JP2018158573A - Conveying device, conveying system, and timing adjustment method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the acquisition accuracy of processing position information by a head unit. SOLUTION: This is a transport device having a head unit and processing an object to be transported at a first moving speed by the head unit, which is installed corresponding to the head unit and is to be transported. A sensor that acquires information on an object, a calculation unit that detects a detection result indicating the position, moving speed, first movement amount, or a combination thereof based on the information acquired by the sensor, and the conveyed object. The measurement unit that measures the second movement amount of the object to move, the detection result when the object to be transported is conveyed at the second movement speed lower than the first movement speed, and the second movement amount. Based on the above, the above problem is solved by providing an adjusting unit for adjusting the acquisition timing of the information used for detecting the detection result by the calculation unit when the transported object is transported at the first moving speed. Solve. [Selection diagram] Fig. 1

Description

  The present invention relates to a transport apparatus, a transport system, and a timing adjustment method.

  Conventionally, methods for performing various processes using a head unit are known. For example, a method of forming an image by a so-called ink jet method in which ink is ejected from a print head is known. A method for improving the print quality of an image printed on a print medium by this image formation is known.

  For example, a method of adjusting the position of the print head is known in order to improve print quality. Specifically, first, a position change in the lateral direction of a web that is a printing medium passing through a continuous paper printing system is detected by a sensor. A method of adjusting the position of the print head in the lateral direction so as to compensate for the position variation detected by this sensor is known (see, for example, Patent Document 1).

  However, for example, when improving the image quality of an image to be formed, it may be required to improve the liquid landing position. On the other hand, in the conventional technology, since the sensor acquisition accuracy is poor, there is a problem that the information acquisition accuracy related to the processing position such as the liquid landing position may deteriorate.

  One aspect of the present invention is that an apparatus that can improve the accuracy of acquiring information related to the processing position of an apparatus that performs processing on an object to be conveyed using a head unit, such as an apparatus that discharges liquid, can be provided. Objective.

In order to solve the above-described problem, it is an aspect of the present invention.
A transport apparatus that has a head unit and performs processing by the head unit for a transported object transported at a first moving speed.
A sensor that is installed corresponding to the head unit and acquires information of the conveyed object;
A calculation unit for detecting a detection result indicating a position, a moving speed, a first moving amount, or a combination of these, based on information acquired by the sensor;
A measuring unit for measuring a second movement amount by which the conveyed object moves;
Based on the detection result and the second movement amount when the transported object is transported at a second moving speed that is lower than the first moving speed, the transported object is moved at the first moving speed. And an adjustment unit that adjusts the acquisition timing of the information used for detection of the detection result by the calculation unit.

  It is possible to provide an apparatus that can improve the acquisition accuracy of information related to the processing position of the conveyed object.

It is the schematic which shows an example of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is the schematic which shows the example of whole structure of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is a figure which shows an example of the external shape of the liquid discharge head unit which concerns on one Embodiment of this invention. It is a schematic diagram which shows the example of arrangement | positioning of the sensor in the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is a block diagram which shows the hardware structural example which implement | achieves the detection part which concerns on one Embodiment of this invention. It is an external view which shows an example of the sensor device which concerns on one Embodiment of this invention. It is a functional block diagram which shows an example of the function structure which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the correlation calculation method which concerns on one Embodiment of this invention. It is a figure which shows an example of the search method of the peak position in the correlation calculation which concerns on one Embodiment of this invention. It is a figure which shows the example of a calculation result of the correlation calculation which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of the control part which concerns on one Embodiment of this invention. It is a block diagram which shows an example of the hardware constitutions of the data management apparatus which the control part which concerns on one Embodiment of this invention has. It is a block diagram which shows an example of the hardware constitutions of the image output apparatus which the control part which concerns on one Embodiment of this invention has. It is a flowchart which shows the process example which concerns on one Embodiment of this invention. It is a timing chart which shows the example of adjustment concerning one embodiment of the present invention. It is a figure which shows an example of the effect which concerns on one Embodiment of this invention. It is a figure which shows an example of the shift | offset | difference of a landing position. It is a timing chart and a conceptual diagram showing an example of detection by a sensor concerning one embodiment of the present invention. It is a figure which shows an example of the influence which eccentricity etc. of a roller have on the shift | offset | difference of a landing position. It is a figure which shows the example from which the position of a recording medium fluctuates in an orthogonal direction. It is a figure which shows an example of the cause which color misregistration arises. It is a block diagram which shows an example of the moving mechanism for moving the liquid discharge head unit which the apparatus which discharges the liquid which concerns on one Embodiment of this invention has. It is the schematic which shows the 1st modification of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is the schematic which shows the 2nd modification of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is the schematic which shows the 3rd modification of the apparatus which discharges the liquid which concerns on one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that, in the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

<Example of overall configuration>
Hereinafter, an example will be described in which the head unit of the transport device is a liquid discharge head unit that discharges liquid, and the position at which the liquid discharge head unit discharges liquid onto the web is the “processing position”. When the head unit included in the transport device is a liquid discharge head unit that discharges liquid, the transport device is a device that discharges liquid.

  FIG. 1 is a schematic view showing an example of an apparatus for ejecting liquid according to an embodiment of the present invention. In such an apparatus for ejecting liquid, the ejected liquid is a recording liquid such as aqueous or oil-based ink. Hereinafter, an example in which the apparatus for ejecting liquid is an image forming apparatus will be described.

  The apparatus 110 that discharges liquid conveys an object to be conveyed such as the web 120. In the example shown in the figure, the apparatus 110 for ejecting liquid forms an image by ejecting liquid onto the web 120 conveyed by the roller 130 or the like. When an image is formed, the web 120 can be said to be a recording medium. The web 120 is a so-called continuous paper printing medium or the like. That is, the web 120 is a roll-shaped sheet or the like that can be wound.

  For example, the device 110 for ejecting liquid is a so-called production printer. In the following description, an example will be described in which the roller 130 adjusts the tension of the web 120 and the web 120 is conveyed in the illustrated direction (hereinafter referred to as “conveying direction 10”). Further, in the figure, the direction orthogonal to the transport direction 10 is referred to as “orthogonal direction 20”. Further, in this example, the device 110 that ejects liquid ejects ink of each of four colors, black (K), cyan (C), magenta (M), and yellow (Y), to obtain a predetermined amount of web 120. This is an inkjet printer that forms an image at a location.

  FIG. 2 is a schematic diagram illustrating an example of the overall configuration of a device for ejecting liquid according to an embodiment of the present invention. As shown in the figure, the device 110 for ejecting liquid has four liquid ejection head units for ejecting each of the four colors of ink.

  Each liquid discharge head unit performs a process of discharging each liquid of each color on the web 120 conveyed in the conveyance direction 10. The web 120 is transported by two pairs of nip rollers, a roller 230, and the like. Hereinafter, of the two pairs of nip rollers, the nip roller installed on the upstream side of each liquid ejection head unit is referred to as a “first nip roller NR1”. On the other hand, a nip roller installed on the downstream side of the first nip roller NR1 and each liquid discharge head unit is referred to as a “second nip roller NR2”. Each nip roller rotates with a conveyed object such as the web 120 interposed therebetween, as shown in the figure. Thus, each nip roller and roller 230 is a mechanism or the like that conveys the web 120 and the like in a predetermined direction.

  In addition, the device 110 that discharges the liquid includes a measuring device that measures the amount of movement of the web 120 by conveyance by the roller 230 or the like. For example, the measuring device is an encoder ENC. Specifically, the encoder ENC is a device including a rotation plate and a rotation detection sensor that reads surface information of the rotation plate. For example, the rotating plate of the encoder ENC is installed on the rotating shaft of the roller 230 as illustrated. When the roller 230 rotates, the rotating plate rotates, and the rotation detection sensor outputs an encoder pulse ENP that is a pulse corresponding to the rotation amount. Note that the measuring device is not limited to the encoder ENC and may be any type of device that can measure the movement amount. Furthermore, the measuring device may be installed at a position other than that shown in the figure as long as the movement amount can be measured.

  The recording medium of the web 120 is preferably long. Specifically, the length of the recording medium is preferably longer than the distance between the first nip roller NR1 and the second nip roller NR2. Furthermore, the recording medium is not limited to the web. That is, the recording medium may be a sheet that is folded and stored, so-called “Z paper” or the like.

  Hereinafter, in the illustrated overall configuration example, each liquid discharge head unit is installed in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side toward the downstream side. To do. That is, the liquid discharge head unit installed on the most upstream side (hereinafter referred to as “black liquid discharge head unit 210K”) is used for black (K). A liquid discharge head unit (hereinafter referred to as “cyan liquid discharge head unit 210C”) installed next to the black liquid discharge head unit 210K is used for cyan (C). Further, a liquid discharge head unit (hereinafter referred to as “magenta liquid discharge head unit 210M”) installed next to the cyan liquid discharge head unit 210C is used for magenta (M). Subsequently, the liquid discharge head unit (hereinafter referred to as “yellow liquid discharge head unit 210Y”) installed on the most downstream side is used for yellow (Y).

  Each liquid discharge head unit discharges each color ink to a predetermined portion of the web 120 based on image data or the like. The position where the ejected ink lands on the web 120 (hereinafter referred to as “landing position”) is almost immediately below the position where the liquid ejection head unit performs ejection (hereinafter referred to as “ejection position”). Hereinafter, an example will be described in which a processing position, which is a position of a transported object that is processed by the liquid discharge head unit, is a discharge position. As described above, since the discharge position for the transported object is almost immediately below the landing position on the transported object, the processing position may be described as the landing position.

  In this example, black ink is ejected to the landing position (hereinafter referred to as “black landing position PK”) of the black liquid discharge head unit 210K. Similarly, cyan ink is ejected to the landing position of the cyan liquid ejection head unit 210C (hereinafter referred to as “cyan landing position PC”). Further, the magenta ink is ejected to the landing position of the magenta liquid ejection head unit 210M (hereinafter referred to as “magenta landing position PM”). The yellow ink is ejected to the landing position (hereinafter referred to as “yellow landing position PY”) of the yellow liquid ejection head unit 210Y.

  Hereinafter, the timing at which each head unit executes processing is referred to as “processing timing”. Specifically, at the processing timing, each liquid ejection head unit ejects ink. For example, the controller 520 connected to each liquid discharge head unit performs control of each processing timing at which each liquid discharge head unit discharges ink and control of the actuator ACT provided in each liquid discharge head unit. Note that two or more controllers and circuits may perform the processing timing control and the actuator ACT control. The actuator ACT will be described later.

  In the illustrated example, a plurality of rollers are installed for each liquid ejection head unit. As shown in the figure, for example, the plurality of rollers are respectively installed on the upstream side and the downstream side across the liquid discharge head units. Specifically, a roller (hereinafter referred to as “first roller”) that supports the web 120 is installed on the upstream side of each landing position for each liquid discharge head unit in the conveyance path of the web 120. In addition, rollers (hereinafter referred to as “second rollers”) that support the web 120 downstream from each landing position are respectively installed.

  In this way, when the first roller and the second roller are installed, so-called “flapping” is reduced at each landing position. The first roller and the second roller are provided on the recording medium conveyance path, and are driven rollers, for example. Further, the first roller and the second roller may be rollers that are rotationally driven by a motor or the like.

  The first roller that is an example of the first support member and the second roller that is an example of the second support member may not be a rotating body such as a driven roller. That is, the first roller and the second roller may be support members that support the object to be conveyed. For example, the first support member and the second support member may be pipes or shafts having a circular cross section. In addition, the first support member and the second support member may be curved plates or the like in which a portion in contact with the object to be conveyed has an arc shape. Hereinafter, an example in which the first support member is the first roller and the second support member is the second roller will be described.

  Specifically, the first black roller CR1K is installed on the upstream side in the conveyance direction of the web 120 at the black landing position PK. On the other hand, the second black roller CR2K is installed downstream from the black landing position PK in the web conveyance direction.

  Similarly, a cyan first roller CR1C and a cyan second roller CR2C are respectively installed on the cyan liquid discharge head unit 210C. Further, a first magenta roller CR1M and a second magenta roller CR2M are installed for the magenta liquid ejection head unit 210M. Further, a yellow first roller CR1Y and a yellow second roller CR2Y are respectively installed on the yellow liquid discharge head unit 210Y.

  FIG. 3 is a diagram showing an example of the outer shape of the liquid discharge head unit according to the embodiment of the present invention. As shown in FIG. 3, FIG. 3A is a schematic plan view illustrating an example of four liquid discharge head units 210 </ b> K to 210 </ b> Y included in the device 110 that discharges liquid.

  As shown in FIG. 3A, each liquid discharge head unit is a line-type head unit in this example. In other words, the apparatus 110 that ejects liquid has four liquid ejection head units 210K, 210C corresponding to black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side in the transport direction 10. 210M and 210Y are arranged.

  In this example, the black (K) liquid discharge head unit 210K has four heads 210K-1, 210K-2, 210K-3, and 210K-4 arranged in a staggered manner in the orthogonal direction. Accordingly, the device 110 that ejects liquid can form an image in the entire region in the width direction (orthogonal direction) in the region (printing region) where the image is formed on the web 120. The configurations of the other liquid discharge head units 210C, 210M, and 210Y are the same as the configuration of the black (K) liquid discharge head unit 210K, and thus the description thereof is omitted.

  In this example, the example in which the liquid discharge head unit is configured by four heads has been described. However, the liquid discharge head unit may be configured by a single head.

<Example of detection unit>
For example, as illustrated in FIG. 2, the apparatus 110 that ejects liquid includes a sensor device that is an example of hardware that configures a detection unit for each liquid ejection head unit. A sensor device is a unit that includes a sensor. The sensor is a device that can acquire information on the web 120. Then, based on the information acquired by the sensor, the device 110 that ejects the liquid detects the position of the recording medium in the orthogonal direction, the transport direction, or both directions. Further, the apparatus 110 for discharging liquid may further include a sensor device in addition to the illustrated sensor device. For example, a sensor device may be further provided upstream of the illustrated sensor device. Hereinafter, as illustrated, a configuration in which the apparatus 110 for ejecting liquid includes four sensor devices will be described. The sensor is not limited to being installed at the illustrated configuration and illustrated position.

  In the following description, a sensor device including a sensor installed for the black liquid discharge head unit 210K is referred to as a “black sensor device SENK”. Similarly, a sensor device installed for the cyan liquid ejection head unit 210C is referred to as “cyan sensor device SENC”. Further, the sensor device installed for the magenta liquid ejection head unit 210M is referred to as “magenta sensor device SENM”. Furthermore, the sensor device installed for the yellow liquid ejection head unit 210Y is referred to as “yellow sensor device SENY”. In the following description, the black sensor device SENK, the cyan sensor device SENC, the magenta sensor device SENM, and the yellow sensor device SENY may be simply referred to as “sensor device SEN”.

  In the following description, “position where the sensor is installed” refers to a position where information is acquired. Therefore, it is not necessary to install all the components of the sensor device at the “position where the sensor is installed”, and devices other than those necessary for obtaining information on the web 120 are connected by cables and installed at other positions. May be. The black sensor device SENK, the cyan sensor device SENC, the magenta sensor device SENM, and the yellow sensor device SENY indicate examples of positions where the sensors are installed.

  The position where the sensor is installed is preferably close to each landing position. If a sensor is installed at a position close to each landing position, the distance between each landing position and the sensor becomes short. And if the distance between each landing position and the sensor is shortened, errors in detection can be reduced. Therefore, the image forming apparatus can detect the position of the conveyed object with high accuracy by the sensor.

  Specifically, the position close to each landing position is, for example, between each first roller and each second roller, as shown in FIG. That is, in the illustrated example, it is desirable that the position where the black sensor device SENK is installed is the inter-black roller INTK1 as illustrated. Similarly, the position where the cyan sensor device SENC is installed is preferably between the cyan rollers INTC1 as shown in the figure. Further, it is desirable that the position where the magenta sensor device SENM is installed is the magenta roller INTM1 as illustrated. Furthermore, the position where the yellow sensor device SENY is installed is preferably between the yellow rollers INTY1, as shown in the figure.

  Thus, when a sensor is installed between the rollers, the sensor can detect the position of the recording medium at a position close to each landing position. In many cases, the meandering speed, which is the movement speed in the orthogonal direction, and the conveyance speed, which is the movement speed in the conveyance direction, are relatively stable between the rollers. Therefore, a device that discharges liquid can accurately detect the position of the object to be transported.

  Furthermore, the position where the sensor is installed is preferably a position closer to the first roller than the landing position between the rollers. That is, the position where the sensor is installed is desirably upstream of each landing position.

  Specifically, the position where the black sensor device SENK is installed is from the black landing position PK to the position where the first black roller CR1K is installed upstream (hereinafter referred to as “black upstream section INTK2”). Is desirable). Similarly, the position where the cyan sensor device SENC is installed is from the cyan landing position PC to the position where the first cyan roller CR1C is installed upstream (hereinafter referred to as “cyan upstream section INTC2”). ) Is desirable. Further, the position where the magenta sensor device SENM is installed is from the magenta landing position PM to the position where the first magenta roller CR1M is installed upstream (hereinafter referred to as “magenta upstream section INTM2”). It is desirable that Furthermore, the position where the yellow sensor device SENY is installed is from the yellow landing position PY to the position where the first yellow roller CR1Y is installed toward the upstream side (hereinafter referred to as “yellow upstream section INTY2”). ) Is desirable.

  When sensors are installed in the black upstream section INTK2, the cyan upstream section INTC2, the magenta upstream section INTM2, and the yellow upstream section INTY2, the device 110 that discharges liquid can detect the position of the conveyed object with high accuracy. .

  When the sensor is installed at such a position, the sensor is installed upstream from each landing position. Therefore, the apparatus 110 that ejects the liquid can first detect the position of the recording medium with high accuracy in the orthogonal direction, the transport direction, or both directions based on the data imaged by the sensor on the upstream side. And since it can detect with sufficient precision in an orthogonal direction, a conveyance direction, or both directions, the apparatus 110 which discharges a liquid can calculate the process timing which each liquid discharge head unit discharges a liquid, the amount which both head units move, or both. That is, when the web 120 is conveyed to the landing position after the position is detected on the upstream side, the processing timing is calculated or the head unit is moved during that time. The position can be changed.

  If the position immediately below each liquid discharge head unit is the position where the sensor is installed, color misregistration may occur due to a delay for the control operation. Therefore, when the position where the sensor is installed is upstream from each landing position, the device 110 that ejects liquid can reduce color misregistration and improve image quality. In addition, there are cases where the vicinity of each landing position or the like is set as a position where a sensor or the like is installed. Therefore, the position where the sensor is installed is desirably closer to each first roller than each landing position.

  In addition, when the control operation delay as described above does not become a problem, and when there is no restriction on the position, the position of the sensor may be, for example, directly below each liquid discharge head unit. When the sensor is directly below, the accurate amount of movement immediately below can be detected by the sensor. Therefore, if the control operation or the like can be performed quickly, it is desirable that the sensor is located closer to the position immediately below each liquid discharge head unit. On the other hand, the sensor does not have to be directly under each liquid discharge head unit, and the same calculation is performed even when the sensor is not directly under.

  If the error can be tolerated, the position of the sensor is directly below each liquid discharge head unit 210 or between each first roller and each second roller and downstream from just below each liquid discharge head unit. Or the like.

  FIG. 4 is a schematic diagram illustrating an example of arrangement of sensors in the apparatus 110 for ejecting liquid according to an embodiment of the present invention. For example, each sensor is disposed at a position where the surface of the web 120 as illustrated can be detected.

  First, each sensor is provided at a position facing each liquid ejection head unit 210 with the web 120 interposed therebetween. Each sensor includes, for example, a light emitting element that irradiates the web 120 with laser light or the like, and an imaging element that images a region irradiated with light by the light emitting element.

  Further, in the illustrated configuration, each liquid ejection head unit and each sensor includes at least a part of each image formation area where each liquid ejection head unit forms an image and each detection area where each sensor detects. It is desirable that the positions overlap each other.

  Actuators ACTK, ACTC, ACTM, and ACTY are actuators that can move each head unit in a direction orthogonal to the transport direction 10. Hereinafter, the actuators may be collectively referred to as “actuator ACT”. The actuator ACT will be described later.

<Example of hardware configuration of sensor device>
Examples of the sensor device include an optical sensor that uses light such as infrared rays, a sensor that uses laser, air pressure, photoelectric, or ultrasonic waves. The optical sensor may be, for example, a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera.

  Furthermore, the optical sensor is preferably a global shutter. With the global shutter, even if the moving speed is high, the optical sensor can reduce the so-called image shift that occurs due to the shift of the shutter release timing, as compared with a rolling shutter or the like. In addition, the sensor preferably has a configuration described below, for example. That is, the sensor for realizing the detection unit is, for example, a sensor that can acquire information on the surface of the recording medium. The sensors may be the same type or different types. In the following description, all the sensors are of the same type. In the following description, the sensor is described as an example of an optical sensor.

  FIG. 5 is a block diagram illustrating a hardware configuration example that implements the detection unit according to the embodiment of the present invention. For example, the detection unit is realized by hardware such as the sensor device SEN as illustrated, and is connected to hardware such as the controller 520.

  First, the sensor device SEN is, for example, the following apparatus.

  FIG. 6 is an external view showing an example of a sensor device according to an embodiment of the present invention.

  The illustrated sensor device SEN is configured to image a speckle pattern or the like formed by applying light from a light source to an object to be conveyed such as a web 120. Specifically, the sensor device SEN first has an optical system such as a semiconductor laser light source (LD) and a collimating optical system (CL). The sensor device SEN captures an image in which a speckle pattern or the like is captured. Therefore, a CMOS image sensor which is an example of a sensor OS, and a telecentric imaging optical system for condensing and imaging a speckle pattern on the CMOS image sensor ( TO). The speckle pattern will be described later.

  In the example of the configuration shown in the figure, the CMOS image sensors provided in different sensor devices SEN capture an image in which a speckle pattern is captured, for example, at each of time “TM1” and time “TM2”. Then, based on the image captured at time “TM1” and the image captured at time “TM2”, controller 520 performs processing such as cross-correlation calculation. In this case, it is possible to calculate the distance that the object has actually moved relative to the distance from one sensor device to the other sensor device between time TM1 and time TM2. Details will be described later. In addition, the same CMOS image sensor captures an image indicating a pattern or the like at each of the separated times TM1 and TM2, and a speckle pattern captured at the time TM1 and an image indicating the speckle pattern captured at the time TM2. It may be used to perform processing such as cross-correlation calculation. In this case, the controller 520 can output the amount of movement of the object from time TM1 to time TM2. In the illustrated example, the size of the sensor device is a width W × depth D × height H 15 × 60 × 32 [mm]. Further, the light source is not limited to an apparatus using laser light. For example, the light source may be an LED (Light Emitting Diode) or an organic EL (Electro-Luminescence). Depending on the type of light source, the pattern may not be a speckle pattern. Hereinafter, an example in which the pattern indicating the surface information is a speckle pattern will be described. The CMOS image sensor is an example of hardware that realizes an imaging unit. In this example, the hardware for performing the correlation calculation is described as the controller 520. However, the correlation calculation may be executed by an FPGA circuit mounted on any sensor device.

  The control circuit 52 controls the sensor OS, the light source LG, and the like inside the sensor device SEN. Specifically, for example, the control circuit 52 outputs a trigger signal to the sensor OS to control the timing at which the sensor OS releases the shutter. Further, the control circuit 52 performs control so that a two-dimensional image can be acquired from the sensor OS. Then, the control circuit 52 captures the image from the sensor OS and sends the generated two-dimensional image to the storage device 53 or the like. The control circuit 52 is, for example, an FPGA circuit.

  The storage device 53 is a so-called memory or the like. It is desirable that the two-dimensional image sent from the control circuit 52 or the like can be divided and stored in different storage areas.

  For example, the controller 520 performs calculation using image data stored in the storage device 53.

  The control circuit 52 and the controller 520 are, for example, a CPU (Central Processing Unit) or an electronic circuit. Note that the control circuit 52, the storage device 53, and the controller 520 need not be different devices. For example, the control circuit 52 and the controller 520 may be one CPU or the like.

<Functional configuration example>
FIG. 7 is a functional block diagram showing an example of a functional configuration according to an embodiment of the present invention. Hereinafter, as illustrated, a combination of the black liquid discharge head unit 210K and the cyan liquid discharge head unit 210C among the detection units installed for each liquid discharge head unit 210 will be described as an example.

  Further, as shown in the figure, the detection unit 52A for the black liquid ejection head unit 210K acquires information related to “A position”, and the detection unit 52B for the cyan liquid ejection head unit 210C acquires information related to “B position”. An example of obtaining will be described. First, the detection unit 52A for the black liquid ejection head unit 210K includes, for example, an imaging unit 16A, an imaging control unit 14A, an image storage unit 15A, and the like. In this example, the detection unit 52B for the cyan liquid ejection head unit 210C has, for example, the same configuration as the detection unit 52A, and includes an imaging unit 16B, an imaging control unit 14B, an image storage unit 15B, and the like. Hereinafter, the detection unit 52A will be described as an example.

  The imaging unit 16A images the web 120 conveyed in the conveyance direction 10 as illustrated. The imaging unit 16A is realized by, for example, the sensor OS illustrated in FIG.

  The imaging control unit 14A includes a shutter control unit 141A and an image capturing unit 142A. The imaging control unit 14A is realized by, for example, the control circuit 52 shown in FIG.

  The image capturing unit 142A acquires an image captured by the imaging unit 16A.

  The shutter control unit 141A controls the timing at which the imaging unit 16A captures an image.

  The image storage unit 15A stores the image captured by the imaging control unit 14A. The image storage unit 15A is realized by, for example, the storage device 53 shown in FIG.

  The calculation unit 53F can calculate the position of the pattern that the web 120 has, the movement speed at which the web 120 is conveyed, and the movement amount at which the web 120 is conveyed based on the images stored in the image storage units 15A and 15B. Configured. And the output of the calculation part 53F is used for both the process of adjusting the acquisition timing mentioned later, and the process of making a process position track the position variation of the web 120 during a process.

  The measurement unit 110F20 has a counting function of counting the encoder pulse ENP output from the encoder ENC attached to the roller 230 shown in FIG.

  The shift amount calculation unit 110F50 is an ideal inter-sensor distance L from “A position” to “B position” based on the output of the measurement unit 110F20 and the output of the calculation unit 53F in the process of adjusting the acquisition timing described later. It has a function of calculating a deviation amount ΔL with respect to. Details of the calculation will be described later.

  The adjustment unit 110F40 outputs data indicating the shutter release timing to the shutter control unit 141A based on the output of the measurement unit 110F20 or based on the output of the measurement unit 110F20 and the calculation result of the deviation amount calculation unit 110F50. Therefore, it has a function of adjusting the acquisition timing. That is, the adjustment unit 110F40 outputs the shutter release timing to the shutter control unit 141A so that an image indicating the “A position” and an image indicating the “B position” are captured at predetermined intervals, respectively. Note that the adjustment unit 110F40 does not output the timing at which the shutter control unit 141B releases the shutter, but adjusts the acquisition timing used to calculate the detection result by changing the image to be calculated by the calculation unit 53F. May be.

  The moving unit 110F80 is a function used for processing for causing the processing position to follow the positional variation of the web 120 being processed, which will be described later. That is, the moving unit 110F80 has a function of moving the liquid ejection head unit 210 based on the amount of movement or moving speed in the orthogonal direction calculated by the calculating unit 53F. The moving unit 110F80 includes an actuator controller CTRC and an actuator. Details of the moving unit 110F80 will be described later.

  The control unit 110F30 performs control to cause each of the plurality of liquid ejection head units to eject liquid. And control part 110F30 is used for the process which makes a processing position track the position change of web 120 under processing mentioned below. When performing the process of tracking the processing position, the control unit 110F30 causes the liquid discharge head unit 210 to discharge the liquid at the processing timing determined based on the detection result by the calculation unit 53F. The first control signal SIG1 for black In addition, the second control signal SIG2 for cyan is output.

  The calculation unit 53F, the measurement unit 110F20, the deviation amount calculation unit 110F50, the adjustment unit 110F40, and the control unit 110F30 are realized by, for example, the controller 520 shown in FIG.

<Description of speckle pattern>
The web 120 is a member having scattering properties on the surface or inside thereof. Therefore, when the web 120 is irradiated with laser light, the reflected light is diffusely reflected. A pattern is formed on the web 120 by the diffuse reflection. That is, the pattern is a so-called speckle pattern called “speckle”. Therefore, when the web 120 is imaged, an image showing a speckle pattern is obtained. Since the position where the speckle pattern is present is known from this image, it is possible to detect where the predetermined position of the web 120 is. This speckle pattern is generated because the irradiated laser beam interferes with the uneven shape formed on the surface or inside of the web 120.

  When the web 120 is conveyed, the speckle pattern of the web 120 is also conveyed. Therefore, when the same speckle pattern is detected at different times, the movement amount is obtained. That is, when the same speckle pattern is detected and the movement amount of the pattern is obtained, the calculation unit 53F can obtain the movement amount of the web 120. When the obtained movement amount is converted per unit time, the calculation unit 53F can obtain the movement speed at which the web 120 has moved. The required moving amount or moving speed is not limited to the conveyance direction of the web 120. Since the imaging unit 16A outputs two-dimensional image data, the calculation unit 53F can obtain a two-dimensional movement amount or movement speed.

<Calculation Example of Calculation Unit 53F>
The calculation unit 53F performs a cross-correlation operation on the image data D1 (n) and D2 (n) acquired by the detection units 52A and 52B. Hereinafter, an image generated by the cross correlation calculation is referred to as a “correlation image”. For example, the calculation unit 53F calculates the shift amount ΔD (n) based on the correlation image.

For example, the cross-correlation calculation is a calculation represented by the following equation (1).

D1 * D2 * = F-1 [F [D1] · F [D2] *] (1)

In the above equation (1), the image data D1 (n), that is, the image data indicating the image picked up at the “position A” is “D1”. Similarly, in the above equation (1), image data D2 (n), that is, image data indicating an image picked up at the “B position” is “D2”. Furthermore, in the above equation (1), the Fourier transform is indicated by “F []”, and the inverse Fourier transform is indicated by “F-1 []”. Furthermore, in the above equation (1), the complex conjugate is indicated by “*” and the cross-correlation operation is indicated by “★”.

  As shown in the above equation (1), when the cross-correlation calculation “D1 * D2” is performed on the image data D1 and D2, image data indicating a correlation image is obtained. If the image data D1 and D2 are two-dimensional image data, the image data indicating the correlation image is two-dimensional image data. When the image data D1 and D2 are one-dimensional image data, the image data indicating the correlation image is one-dimensional image data.

In the correlation image, for example, when a broad luminance distribution becomes a problem, the phase only correlation method may be used. The phase only correlation method is, for example, a calculation represented by the following equation (2).

D1 * D2 * = F-1 [P [F [D1]] · P [F [D2] *]] (2)

In the above equation (2), “P []” indicates that only the phase is extracted from the complex amplitude. The amplitudes are all “1”.

  In this way, the calculation unit 53F can calculate the shift amount ΔD (n) based on the correlation image even with a broad luminance distribution.

  The correlation image indicates the correlation between the image data D1 and D2. Specifically, as the degree of coincidence between the image data D1 and D2 increases, a sharp peak, that is, a so-called correlation peak luminance is output at a position closer to the center of the correlation image. When the image data D1 and D2 match, the center and peak position of the correlation image overlap.

<Example of correlation calculation>
The detailed contents of the correlation calculation will be described.

  FIG. 8 is a block diagram showing an example of a correlation calculation method according to an embodiment of the present invention. For example, when the calculation unit 53F performs the correlation calculation with the configuration as illustrated, the calculation unit 53F outputs a detection result indicating the relative position, the moving amount, the moving speed, or a combination thereof of the web 120 at the position where the image data is captured. can do.

  Specifically, as illustrated, the calculation unit 53F includes a first two-dimensional Fourier transform unit FT1, a second two-dimensional Fourier transform unit FT2, a correlation image data generation unit DMK, a peak position search unit SR, and a calculation unit. This is a configuration having a CAL and a conversion result storage unit MEM.

  The first two-dimensional Fourier transform unit FT1 transforms the first image data D1. Specifically, the first two-dimensional Fourier transform unit FT1 includes a Fourier transform unit FT1a for the orthogonal direction and a Fourier transform unit FT1b for the transport direction.

  The orthogonal direction Fourier transform unit FT1a performs one-dimensional Fourier transform on the first image data D1 in the orthogonal direction. Then, the Fourier transform unit FT1b for the transport direction performs one-dimensional Fourier transform on the first image data D1 in the transport direction based on the conversion result by the Fourier transform unit FT1a for the orthogonal direction. In this way, the Fourier transform unit FT1a for the orthogonal direction and the Fourier transform unit FT1b for the transport direction perform one-dimensional Fourier transform in the orthogonal direction and the transport direction, respectively. The first two-dimensional Fourier transform unit FT1 outputs the conversion result thus converted to the correlation image data generation unit DMK.

  Similarly, the second two-dimensional Fourier transform unit FT2 transforms the second image data D2. Specifically, the second two-dimensional Fourier transform unit FT2 includes a Fourier transform unit FT2a for orthogonal directions, a Fourier transform unit FT2b for transport directions, and a complex conjugate unit FT2c.

  The orthogonal direction Fourier transform unit FT2a performs one-dimensional Fourier transform on the second image data D2 in the orthogonal direction. Then, the Fourier transform unit FT2b for the transport direction performs one-dimensional Fourier transform on the second image data D2 in the transport direction based on the conversion result by the Fourier transform unit FT2a for the orthogonal direction. In this way, the Fourier transform unit FT2a for the orthogonal direction and the Fourier transform unit FT2b for the transport direction perform one-dimensional Fourier transform in the orthogonal direction and the transport direction, respectively.

  Next, the complex conjugate unit FT2c calculates the complex conjugate of the conversion result obtained by the Fourier transform unit FT2a for the orthogonal direction and the Fourier transform unit FT2b for the transport direction. Then, the second two-dimensional Fourier transform unit FT2 outputs the complex conjugate calculated by the complex conjugate unit FT2c to the correlation image data generation unit DMK.

  Subsequently, the correlation image data generation unit DMK outputs the conversion result of the first image data D1 output from the first two-dimensional Fourier transform unit FT1 and the second image output from the second two-dimensional Fourier transform unit FT2. Correlation image data is generated based on the conversion result of the data D2.

  The correlation image data generation unit DMK includes an integration unit DMKa and a two-dimensional inverse Fourier transform unit DMKb.

  The integrating unit DMKa integrates the conversion result of the first image data D1 and the conversion result of the second image data D2. Then, the integration unit DMKa outputs the integration result to the two-dimensional inverse Fourier transform unit DMKb.

  The two-dimensional inverse Fourier transform unit DMKb performs a two-dimensional inverse Fourier transform on the integration result obtained by the integration unit DMKa. In this way, when the two-dimensional inverse Fourier transform is performed, correlation image data is generated. Then, the two-dimensional inverse Fourier transform unit DMKb outputs the correlation image data to the peak position search unit SR.

  In the generated correlation image data, the peak position search unit SR searches for a peak position having a peak luminance (peak value) that is the steepest (that is, the rising edge is steep). First, the correlation image data is input with a value indicating the intensity of light, that is, the luminance. The luminance is input in a matrix.

  In the correlation image data, the luminance is arranged at the pixel pitch interval of the area sensor, that is, at the pixel size interval. Therefore, it is desirable that the search for the peak position is performed after performing so-called subpixel processing. Thus, when the subpixel processing is performed, the peak position can be searched with high accuracy. Therefore, the calculation unit 53F can output the position, the movement amount, the movement speed, and the like with high accuracy.

  For example, the search by the peak position search unit SR is performed as follows.

  FIG. 9 is a diagram illustrating an example of a peak position search method in correlation calculation according to an embodiment of the present invention. In the figure, the horizontal axis indicates the position in the transport direction in the image indicated by the correlation image data. On the other hand, the vertical axis indicates the luminance of the image indicated by the correlation image data.

  Hereinafter, three data of the first data value q1, the second data value q2, and the third data value q3 in the luminance indicated by the correlation image data will be described as an example. That is, in this example, the peak position search unit SR searches for the peak position P in the curve k connecting the first data value q1, the second data value q2, and the third data value q3.

  First, the peak position search unit SR calculates each difference in luminance of the image indicated by the correlation image data. And the peak position search part SR extracts the combination of the data value from which the difference value becomes the largest among the calculated differences. Next, the peak position search unit SR extracts a combination adjacent to a combination of data values having the largest difference value. In this way, the peak position search unit SR can extract three pieces of data as shown in the first data value q1, the second data value q2, and the third data value q3. When the curve k is calculated by connecting the three extracted data, the peak position search unit SR can search for the peak position P. In this way, the peak position search unit SR can search for the peak position P at a higher speed by reducing the amount of calculation such as subpixel processing. Note that the position of the combination of data values with the largest difference value is the steepest position. The subpixel processing may be processing other than the above processing.

  As described above, when the peak position search unit SR searches for a peak position, for example, the following calculation result is obtained.

  FIG. 10 is a diagram illustrating a calculation result example of the correlation calculation according to the embodiment of the present invention. The figure shows the correlation strength distribution of the cross-correlation function. In the figure, the X axis and the Y axis indicate pixel serial numbers. A peak position such as a “correlation peak” shown in the figure is searched by the peak position search unit SR.

  The calculation unit CAL calculates a relative position, a moving amount, a moving speed, or the like of the web. For example, the calculation unit CAL can calculate the relative position and the movement amount by calculating the difference between the center position of the correlation image data and the peak position searched by the peak position search unit SR.

  Further, the calculation unit CAL can calculate the movement speed by dividing the movement amount by time, for example.

  As described above, the calculation unit 53F can detect the relative position, the movement amount, the movement speed, and the like by the correlation calculation. Note that the detection method of the relative position, the movement amount, the movement speed, and the like is not limited to this. For example, the calculation unit 53F may detect a relative position, a movement amount, a movement speed, or the like as follows.

  First, the calculation unit 53F binarizes each luminance of the first image data and the second image data. That is, the calculation unit 53F sets “0” if the luminance is equal to or lower than a preset threshold value, and sets “1” if the luminance is larger than the threshold value. The calculation unit 53F may detect the relative position by comparing the binarized first image data and second image data.

  In addition, although the figure demonstrated the example which has a fluctuation | variation in a Y direction, when there exists a fluctuation | variation in a X direction, a peak position generate | occur | produces in the position shifted | deviated also to the X direction.

  The calculation unit 53F may detect the relative position, the movement amount, the movement speed, or the like by a detection method other than this. For example, the calculation unit 53F may detect the relative position from each pattern appearing in each image data by so-called pattern matching processing or the like.

<Description of Controller 520>
The controller 520 (FIG. 2), which is an example of the control unit, has a configuration described below, for example.

  FIG. 11 is a block diagram illustrating an example of a hardware configuration of a control unit according to an embodiment of the present invention. For example, the controller 520 includes a host device 71 that is an information processing device and the like, and a printer device 72. In the illustrated example, the controller 520 causes the printer device 72 to form an image on the recording medium based on the image data and control data input from the host device 71.

  The host device 71 is, for example, a PC (Personal Computer). The printer device 72 includes a printer controller 72C and a printer engine 72E.

  The printer controller 72C controls the operation of the printer engine 72E. First, the printer controller 72C transmits / receives control data to / from the host device 71 via the control line 70LC. Further, the printer controller 72C transmits / receives control data to / from the printer engine 72E via the control line 72LC. By transmitting and receiving this control data, various printing conditions and the like indicated by the control data are input to the printer controller 72C, and the printer controller 72C stores the printing conditions and the like using a register or the like. Next, the printer controller 72C controls the printer engine 72E based on the control data, and forms an image according to the print job data, that is, the control data.

  The printer controller 72C includes a CPU 72Cp, a print control device 72Cc, and a storage device 72Cm. The CPU 72Cp and the print control device 72Cc are connected by a bus 72Cb and communicate with each other. The bus 72Cb is connected to the control line 70LC via a communication I / F (interface) or the like.

  The CPU 72Cp controls the operation of the entire printer device 72 by a control program or the like. That is, the CPU 72Cp is an arithmetic device and a control device.

  Based on the control data transmitted from the host device 71, the print control device 72Cc transmits / receives data indicating a command or status to the printer engine 72E. Thereby, the print control device 72Cc controls the printer engine 72E.

  Data lines 70LD-C, 70LD-M, 70LD-Y and 70LD-K, that is, a plurality of data lines are connected to the printer engine 72E. Then, the printer engine 72E receives image data from the upper apparatus 71 via a plurality of data lines. Next, the printer engine 72E performs image formation for each color based on control by the printer controller 72C.

  The printer engine 72E includes data management devices 72EC, 72EM, 72EY, and 72EK, that is, a plurality of data management devices. The printer engine 72E includes an image output device 72Ei and a conveyance control device 72Ec.

  FIG. 12 is a block diagram illustrating an example of a hardware configuration of a data management apparatus included in the control unit according to the embodiment of the present invention. For example, the plurality of data management devices have the same configuration. Hereinafter, an example in which each data management device has the same configuration will be described, and the data management device 72EC will be described as an example. Therefore, the overlapping description is omitted.

  The data management device 72EC includes a logic circuit 72ECl and a storage device 72ECm. As shown in the figure, the logic circuit 72ECl is connected to the host device 71 via the data line 70LD-C. Further, the logic circuit 72ECl is connected to the print control device 72Cc via the control line 72LC. The logic circuit 72ECl is realized by an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or the like.

  The logic circuit 72ECl stores the image data input from the host device 71 in the storage device 72ECm based on the control signal input from the printer controller 72C (FIG. 11).

  The logic circuit 72ECl reads cyan image data Ic from the storage device 72ECm based on a control signal input from the printer controller 72C. Next, the logic circuit 72ECl sends the read cyan image data Ic to the image output device 72Ei.

  Note that the storage device 72ECm desirably has a capacity capable of storing image data of about three pages. When image data of about three pages can be stored, the storage device 72ECm can store image data input from the host device 71, image data during image formation, and image data for next image formation.

  FIG. 13 is a block diagram illustrating an example of a hardware configuration of an image output apparatus included in a control unit according to an embodiment of the present invention. As shown in the figure, the image output device 72Ei includes an output control device 72Eic, a black liquid discharge head unit 210K, a cyan liquid discharge head unit 210C, a magenta liquid discharge head unit 210M, and a yellow liquid discharge head that are liquid discharge head units for each color. Control unit 210Y.

  The output control device 72Eic outputs the image data of each color to the liquid ejection head unit of each color. In other words, the output control device 72Eic controls the liquid discharge head unit of each color based on the input image data.

  The output control device 72Eic controls a plurality of liquid ejection head units simultaneously or individually. That is, the output control device 72Eic performs control to change the timing at which each liquid ejection head unit ejects liquid in response to timing input. The output control device 72Eic may control any of the liquid ejection head units based on a control signal input from the printer controller 72C. Further, the output control device 72Eic may control any of the liquid ejection head units based on an operation by the user.

  The printer device 72 is an example in which a route for inputting image data from the host device 71 and a route used for transmission / reception between the host device 71 and the printer device 72 based on the control data are different from each other.

  The printer device 72 may be configured to form an image with one black color, for example. In order to increase the speed of image formation when performing image formation with one black color, for example, a configuration including one data management device and four black liquid discharge head units may be used. In this way, black ink is ejected by each of the plurality of black liquid ejection head units. Therefore, it is possible to perform faster image formation as compared with a configuration in which one black liquid discharge head unit is used.

  The conveyance control device 72Ec is a motor or the like that conveys the web 120. For example, the conveyance control device 72Ec controls a motor or the like connected to each roller or the like to convey the web 120.

<Processing example>
FIG. 14 is a flowchart showing an example of processing according to an embodiment of the present invention. For example, the apparatus 110 that discharges liquid performs the following overall processing.

  Further, in the following example, the device 110 that ejects liquid transports the object to be transported in the transport direction at the “first moving speed” when performing image formation. On the other hand, when adjusting the acquisition timing of data used to calculate the detection result, the apparatus 110 that ejects liquid uses a preset moving speed for adjustment (hereinafter referred to as “second moving speed”). It is desirable to carry out adjustment by conveying the object to be conveyed in the conveying direction. Hereinafter, a preferred embodiment will be described as an example.

  In step S10, the device 110 that discharges the liquid sets the second movement speed. For example, the apparatus 110 that ejects liquid performs detection timing adjustment as a preparation stage before image formation. Further, it is desirable that the second movement speed is lower than the first movement speed. For example, the first moving speed is a high speed such as 1000 mm / s (millimeter per second) or more. On the other hand, the second moving speed is a low speed of about several tens of mm / s, for example. By conveying at such a low speed, disturbances such as slip of the web 120 can be suppressed.

  In step S11, the adjustment unit 110F40 of the device 110 that ejects liquid sets an initial value as the correction value ΔL. For example, the initial value is “0” or the like. In addition, a value to be an initial value may be set in advance by a user or the like.

  In step S12, the adjustment unit 110F40 of the apparatus 110 that ejects liquid calculates a value obtained by adding the relative distance L, which is the interval at which the sensors are installed, and the correction value ΔL.

  In the initial state, “ΔL = 0” is set in step S11, so that “L + ΔL = L”. That is, the initial state is a so-called ideal state where there is no correction by the correction value ΔL. Therefore, in the ideal state, the object to be transported takes time of “L ÷ movement speed” to be transported at the relative distance L that is the distance between the sensors.

  In step S13, the measurement unit 110F20 of the apparatus 110 that discharges the liquid measures the movement amount when the second movement speed is set and is conveyed from the output of the encoder ENC or the like. Hereinafter, the movement amount of the conveyed object calculated by the calculation unit 53F is referred to as a “first movement amount”. On the other hand, the amount of movement of the conveyed object measured by a measuring unit such as an encoder is referred to as a “second movement amount”.

  In step S13, the measurement unit 110F20 counts the encoder pulse ENP with reference to the home position of the encoder ENC in order to determine whether or not the sensor is ready to start imaging. The encoder pulse ENP is an example of the second movement amount. The encoder ENC outputs an encoder pulse ENP at every predetermined rotation angle according to the rotation amount of the roller 230, that is, the movement amount of the conveyed object. Therefore, when the encoder pulse ENP is counted, the device 110 that ejects liquid can determine the timing of starting imaging by multiplying the interval at which the encoder pulse is output by the counter value. The count value counted in steps S13 and S14 is set as the first count value.

  In step S14, the adjustment unit 110F40 of the apparatus 110 that ejects liquid determines whether or not the first count value is equal to a set value that is a timing at which the sensor starts imaging. For example, a plurality of set values are set from 0 ° to 360 ° with respect to the home position of the encoder ENC so as to be detected and canceled by fluctuations in the rotation period of the roller 230. The cancellation of the period variation will be described later.

  Next, when the adjustment unit 110F40 of the device 110 that ejects liquid determines that the first count value is equal to the set value (YES in step S14), the device 110 that ejects liquid proceeds to step S15. On the other hand, when the adjustment unit 110F40 of the device 110 that ejects liquid determines that the first count value is not equal to the set value (NO in step S14), the device 110 that ejects liquid proceeds to step S13.

  In step S15, the imaging unit 16A of the device 110 that discharges the liquid captures the first image. That is, in the functional configuration shown in FIG. 7, image data on the upstream side (corresponding to “position A”) is captured.

  In step S16, the measurement unit 110F20 of the apparatus 110 that ejects liquid counts the encoder pulse ENP. As described above, the encoder pulse ENP is an example of the second movement amount. The second movement amount measured in step S16 is a value starting from the position where the first sensor detects. Specifically, in the case shown in FIG. 2, the count value starting from the position of the black sensor device SENK is set as the second count value. The apparatus 110 that ejects the liquid measures the relative distance L between the black sensor device SENK and the cyan sensor device SENC by counting encoder pulses ENP that are examples of the second movement amount. This count value is set as the second count value. The relative distance L can also be said to be a reference value for the distance between the sensors.

  Further, the counter for counting the first count value and the counter for counting the second count value may be different counters. For example, the counter may be different for each sensor interval. For example, in the example shown in FIG. 2, the black sensor device SENK to the cyan sensor device SENC, and the black sensor device SENK to the magenta sensor device SENM may be counted by different counters. Further, the distance between the sensors does not need to be from the black sensor device SENK, and may be counted from the cyan sensor device SENC to the magenta sensor device SENM.

  In step S <b> 17, the adjustment unit 110 </ b> F 40 of the apparatus 110 that ejects liquid determines whether or not the second count value obtained by counting the second movement amount is equal to “L + ΔL”. That is, in step S17, the apparatus that ejects the liquid determines whether or not the second count value obtained by counting the encoder pulse ENP is the sensor interval between the upstream sensor and the downstream sensor, that is, “L + ΔL”. Judging.

  Next, when the adjustment unit 110F40 of the device 110 that ejects liquid determines that the second movement amount is equal to “L + ΔL” (YES in step S17), the device 110 that ejects liquid proceeds to step S18. On the other hand, when adjustment unit 110F40 of the device that discharges the liquid determines that the second movement amount is not equal to “L + ΔL” (NO in step S17), device 110 that discharges the liquid proceeds to step S16.

  In step S <b> 18, the imaging unit 16 </ b> B of the device 110 that ejects liquid captures a second image. That is, in the functional configuration shown in FIG. 7, image data on the downstream side (corresponding to “B position”) is captured.

  The apparatus 110 that ejects liquid repeats Steps S13 to S19, thereby calculating a plurality of deviation amounts using a plurality of rotational positions as start timings, statistically processing the plurality of deviation amounts, and calculating an average value ΔDave or the like. It is desirable to calculate As described above, a plurality of rotational positions are stored as set values. By capturing the first image at different rotational positions, it is possible to acquire deviation amounts from different rotational angles. By statistically processing a plurality of deviation amounts and calculating the average value ΔDave, the rotation cycle fluctuation of the roller 230 can be canceled.

  First, if there is upstream image data and downstream image data, the apparatus 110 that ejects the liquid actually moves when L + ΔL moves based on the result of the correlation calculation as described above by the calculation unit 53F. The position of the web 120 can be detected from the image captured by the sensor. Thus, the deviation amount calculation unit 110F50 can detect how much the sensor interval has deviated with respect to the distance of L + ΔL. That is, the actual sensor interval can be detected. For example, when the first image data and the second image data are obtained in step S15 and step S18, the apparatus 110 that ejects the liquid detects the deviation amount of the sensor interval between the black sensor device SENK and the cyan sensor device SENC. it can. In this manner, the device 110 that ejects liquid can obtain a value indicating the amount of deviation of the sensor interval (hereinafter simply referred to as “deviation amount”) based on the detection result of the sensor.

Therefore, as shown in the drawing, when the first image data and the second image data are acquired a plurality of times, the deviation amount calculation unit 110F50 of the device 110 that ejects liquid can calculate a plurality of deviation amounts. Note that the predetermined number of times indicating how many deviation amounts are calculated is set in advance by a user or the like.

  In step S19, the deviation amount calculation unit 110F50 of the apparatus 110 that ejects liquid determines whether or not the number of deviations calculated is equal to the predetermined number. That is, the deviation amount calculation unit 110F50 of the apparatus 110 that ejects liquid repeats steps S13 to S19 to determine whether or not a preset number and deviation amount are collected.

  Next, when the deviation amount calculation unit 110F50 of the device 110 that ejects liquid determines that the deviation count is equal to the predetermined number of times (YES in step S19), the device 110 that ejects liquid proceeds to step S20. On the other hand, when the deviation amount calculation unit 110F50 of the device 110 that ejects liquid determines that the deviation count is not equal to the predetermined number of times (NO in step S19), the device 110 that ejects liquid proceeds to step S16.

  In step S20, the deviation amount calculation unit 110F50 of the apparatus 110 that ejects liquid calculates an average value ΔDave of the deviation amount and the like. That is, in step S20, the deviation amount calculation unit 110F50 of the apparatus 110 that ejects liquid performs statistical processing on a plurality of deviation amounts to calculate a statistical value. For example, the statistic is an average value or a moving average value. Hereinafter, an example in which the statistical value is the average value ΔDave will be described.

  In step S21, the adjustment unit 110F40 of the apparatus 110 that ejects liquid determines whether or not the average value ΔDave is smaller than the determination value. Note that the determination value is a value indicating a range of an allowable deviation amount based on specifications and the like. The determination value is a value set in advance by the user or the like. Therefore, the adjustment unit 110F40 of the apparatus 110 that ejects liquid determines whether or not the average value ΔDave is in an allowable range.

  Next, when the adjustment unit 110F40 of the device 110 that ejects liquid determines that the average value ΔDave is smaller than the determination value (YES in step S21), the device that ejects liquid proceeds to step S23. On the other hand, when adjustment unit 110F40 of the device that ejects liquid determines that average value ΔDave is equal to or greater than the determination value (NO in step S21), device 110 that ejects liquid proceeds to step S22.

  In step S22, the adjustment unit 110F40 of the device 110 that discharges the liquid calculates the correction value ΔL. Thus, the calculated correction value ΔL is reflected in step S12. In this way, the device 110 that ejects liquid can adjust the data acquisition timing of each sensor. Details of the adjustment will be described later.

  In step S <b> 23, the apparatus for ejecting liquid performs processing by the head unit such as image formation while moving the object to be conveyed at the first movement speed, that is, at a high speed. And the calculation part 53F of the apparatus which discharges a liquid calculates the detection results, such as a position of the web 120, based on the output data of the sensor acquired by the acquisition timing correct | amended by correction value (DELTA) L during a process. Further, as described above, the apparatus 110 for ejecting liquid adjusts the processing timing for performing liquid ejection and the like during processing based on the detection result obtained in this manner, and adjusts each head unit in the orthogonal direction. Move or combine them.

  As described above, the example in which the apparatus that discharges the liquid performs the adjustment before the process (step S23 and the like) is performed has been described. However, the adjustment may be performed between jobs.

<Example of acquisition timing adjustment>
FIG. 15 is a timing chart showing an adjustment example according to an embodiment of the present invention. When the process illustrated in FIG. 14 is performed, the adjustment unit 110F40 of the apparatus 110 that discharges liquid can be adjusted as illustrated, for example.

  Hereinafter, as illustrated, a combination of a black sensor device SENK (an example of an upstream sensor) and a cyan sensor device SENC (an example of a downstream sensor) will be described as an example. Furthermore, in this example, it is assumed that the black sensor device SENK and the cyan sensor device SENC are installed such that the sensor interval between the sensors provided therein, that is, the relative distance L is “100 mm (millimeters)”. . However, in this example, it is assumed that an attachment error M has occurred in attaching the sensor. In the following description, the attachment error M is “+0.5 mm”, that is, as shown in the drawing, the cyan sensor device SENC is attached to the position where “M = + 0.5 mm” from the relative distance L. To do. In the following description, it is assumed that there is no disturbance other than the attachment error M.

  In this example, it is assumed that the encoder pulse ENP is “1 pulse (pulse) = 0.1 mm”. Then, the encoder counter CN2 counts the encoder pulse ENP.

  Next, the acquisition timing signal SH1 is a signal that controls the timing at which the black sensor device SENK performs imaging. That is, as illustrated, at the first acquisition timing TS1 at which the acquisition timing signal SH1 is asserted (ON), the black sensor device SENK releases the shutter and generates the first image data D1.

  Similarly, the acquisition timing signal SH2 is a signal that controls the timing at which the cyan sensor device SENC performs imaging. That is, as illustrated, at the second acquisition timing TS2 at which the acquisition timing signal SH2 is asserted, the cyan sensor device SENC releases the shutter and generates the second image data D2. In this example, the time after which the acquisition timing signal SH2 is asserted (ON) is adjusted after the acquisition timing signal SH1 is asserted. Therefore, in this example, at the timing when the acquisition timing signal SH1 is asserted, that is, at the first acquisition timing TS1, the encoder counter CN2 is reset and the encoder counter CN2 starts counting up as illustrated.

  In the process shown in FIG. 14, first, an initial value corresponding to a state in which there is no attachment error M is set (step S11). Thus, when set, since “correction value ΔL = 0”, when the second movement amount is the relative distance L, that is, the encoder counter CN2 becomes “1000” (YES in step S17), the cyan sensor The device SENC releases the shutter and generates the second image data D2 (pre-adjustment timing TBE, step S18).

  Even if the second image data D2 is generated at a timing such as the pre-adjustment timing TBE, if the moving speed is low, such as the second moving speed, the web 120 is unlikely to slip, so the second image data D2 is generated. The image data D2 is highly likely to include a predetermined portion indicated by the first image data D1. Therefore, for example, the apparatus that ejects the liquid can calculate the amount of deviation by comparing the position of a predetermined location in the second image data D2 with the position such as the center coordinates of the second image data D2. As described above, when the deviation amount is repeatedly calculated a predetermined number of times, the device that ejects liquid can calculate the average deviation amount ΔDave (step S20). Hereinafter, the average value ΔDave is also assumed to be “−0.5 mm”.

  In the example illustrated, the acquisition timing of the cyan sensor device SENC is adjusted to a timing delayed by “5 pulses” from the pre-adjustment timing TBE because the average value ΔDave is “−0.5 mm”.

  Therefore, in this example, the correction value ΔL is calculated as “+0.5 mm” so as to cancel the average value ΔDave (step S22). When such a correction value ΔL is set (step S12), the acquisition timing of the cyan sensor device SENC is adjusted by the correction value ΔL from the pre-adjustment timing TBE to become the second acquisition timing TS2. That is, the adjustment unit 110F40 of the apparatus 110 that ejects liquid sets the acquisition timing of the cyan sensor device SENC to “L + ΔL = 1000 + 5 = 1005 pulse” after adjustment.

  When such adjustment is performed, for example, the following effects are obtained.

<Effect example>
FIG. 16 is a diagram illustrating an example of the effect according to the embodiment of the present invention. First, it is assumed that the sensor has, for example, one pixel of “8 μm (micrometer)” and 256 pixels in the transport direction. In the case of a sensor having such a specification, the range in which the sensor can detect the position and the like is about “2 mm”. That is, the range in which the sensor can detect the position and the like is about “± 1 mm”.

  Hereinafter, it is assumed that the specification is such that the sensor can detect a range of “± 1 mm”. That is, in the illustrated example, the sensor can detect the position of the conveyed object in the illustrated detection range RAN1 around the origin “0”.

  Furthermore, in the following description, it is assumed that the transported object varies within a range of “± 0.6 mm”. That is, the position of the transported object fluctuates in the illustrated fluctuation range RAN2 around the origin “0” in the illustrated example due to a slip or the like. As shown in the figure, since the detection range RAN1 is in the range of “± 1 mm”, the sensor can detect the position of the conveyed object that fluctuates within the fluctuation range RAN2 if there is no attachment error M or the like. The fluctuation is output as a value detected by the sensor, that is, a value on the vertical axis.

  On the other hand, for example, as in FIG. 15, it is assumed that the attachment error M is “+0.5 mm”. As described above, when there is an attachment error M, in this figure, the conveyed object fluctuates around “+0.5 mm”. Therefore, when there is an attachment error M, the conveyed object fluctuates within a fluctuation range RAN3 that is a range of “−0.1 mm to +1.6 mm”. Variations such as the variation range RAN3 include variations outside the detection range RAN1. Specifically, among the fluctuations such as the fluctuation range RAN3, fluctuations of “+1.0 mm to +1.6 mm” exceeding “+1.0 mm” cannot be detected by the sensor having the illustrated specification.

  Therefore, as shown in FIG. 15, when adjustment is performed, the device 110 that ejects liquid can cancel the attachment error M and the like. That is, in the example shown in FIG. 16, when the adjustment is performed, the influence of the attachment error M is reduced, so that the device 110 that ejects the liquid can detect the variation of the conveyed object as in the variation range RAN2. it can.

  With the configuration as described above, the apparatus 110 that ejects liquid can adjust the acquisition timing of data used for detection of the detection result by the calculation unit 53F illustrated in FIG. 7 by using the adjustment unit 110F40.

  For example, if a sensor that realizes the detection unit 52A and the detection unit 52B is newly installed or the position where the sensor is installed is changed, an attachment error M or the like is likely to occur. Thus, when there is an attachment error M or the like, the sensor interval is often not a reference value such as the relative distance L or the like.

  Therefore, the apparatus 110 that ejects the liquid adjusts the acquisition timing by, for example, the process illustrated in FIG. 14 before the process such as the image formation is performed (step S23 in FIG. 14). Specifically, for example, as illustrated in FIG. 15, the apparatus 110 that ejects liquid first measures the second movement amount like the encoder counter CN2 by the measurement unit 110F20 illustrated in FIG. 7. When the second movement amount reaches a predetermined value, for example, the second image data D2 can be generated by the downstream detection unit 52B shown in FIG. 7 at the pre-adjustment timing TBE shown in FIG. Next, the apparatus 110 that ejects the liquid can calculate the shift amount ΔD based on the detection result output at the pre-adjustment timing TBE such as the second image data D2.

<Calculation of calculation part in process>
As illustrated in FIG. 7, the imaging unit 16 </ b> A and the imaging unit 16 </ b> B are installed at predetermined intervals in the transport direction 10. Then, the web 120 is imaged at each position by the imaging unit 16A and the imaging unit 16B. During processing, the web 120 is moving at the first moving speed.

  By the adjustment as described above, the imaging timing of the imaging unit 16A and the imaging interval of the imaging unit 16B become “L + ΔL”. In the following example, the imaging unit 16A is the most upstream sensor, and an example in which the imaging timing of the imaging unit 16A is not adjusted will be described.

  Adjustment unit 110F40 outputs an imaging instruction to shutter control unit 141A. Further, the adjustment unit 110F40 outputs an imaging instruction to the shutter control unit 141B at a position of L + ΔL after outputting an imaging instruction to the shutter control unit 141A based on the data output from the measurement unit 110F20.

  The imaging unit 16A and the imaging unit 16B perform imaging at intervals of L + ΔL and output image data including a speckle pattern. Based on this image data, the calculation unit 53F performs a correlation calculation.

  Next, based on the result of the correlation calculation, information such as a position difference, a movement amount, or a movement speed between the image data D1 and the image data D2 at L + ΔL is output. For example, in the orthogonal direction, it is possible to detect how much the web 120 has moved in the orthogonal direction between the image data D1 and the image data D2. Note that the result of the correlation calculation may be detected not as a movement amount but as a movement speed. In this way, the calculation unit 53F can calculate the amount of movement by which the moving unit 110F80 moves the cyan liquid ejection head unit 210C in the orthogonal direction during processing from the calculation result of the correlation calculation. The movement in the orthogonal direction will be described later.

  Furthermore, the calculation unit 53F can determine how much the web movement amount in the transport direction has shifted based on the result of the correlation calculation. Based on this result, the controller 110F30 can change the ejection timing of the liquid ejection head unit. The change in processing timing such as liquid ejection will be described later.

  If the sensor is also used in this way, the cost for installing the device in each direction can be reduced. In addition, since the number of sensors can be reduced, space can be saved.

<Processing timing change example>
FIG. 17 is a diagram illustrating an example of deviation of landing positions. The figure shows an example of the deviation of the position where the liquid has landed without correction.

  The first graph G1 shows the actual web position. On the other hand, the second graph G2 is the position of the web calculated based on the encoder pulse from the encoder ENC. That is, if there is a difference between the first graph G1 and the second graph G2, the actual web position in the transport direction is different from the calculated web position, so that the landing position is likely to be misaligned. .

  For example, in the liquid discharge by the black liquid discharge head unit 210K, a deviation amount σ is generated. Further, the amount of deviation may be different for each liquid ejection head unit. That is, in the ejection other than black, each misalignment amount is often different from the misalignment amount σ.

  The amount of misalignment is caused by, for example, roller eccentricity, thermal expansion of the roller, slip generated between the web and the roller, expansion / contraction of the recording medium, and combinations thereof.

  FIG. 18 is a timing chart and a conceptual diagram showing an example of detection by a sensor according to an embodiment of the present invention.

  In the illustrated example, the horizontal axis represents the encoder pulse ENP output from the encoder ENC. Further, the movement amount per pulse of the encoder pulse ENP is defined as a unit movement amount PD. The first acquisition timing TS1 is an acquisition timing at which the black sensor device SENK acquires data. The first processing timing TE1 is the processing timing at which black liquid is discharged, and the second acquisition timing TS2 is the cyan sensor device SENC installed between the black liquid discharging head unit 210K and the cyan liquid discharging head unit 210C. Is the acquisition timing for acquiring data. The pre-adjustment timing TBE is a timing at which the cyan sensor device SENC performs detection when the adjustment shown in the flow of FIG. 14 is not performed. Further, the pre-change processing timing TE2 ′ is set based on the timing at which the cyan liquid is scheduled to be discharged, and the second processing timing TE2 is changed based on the image data captured by the sensor device SENK and the sensor device SENC. It is set as the process timing at which the liquid is discharged.

  In this example, a position where the cyan sensor device SENC performs detection is hereinafter referred to as a “detection position”. As described above, the detection position is assumed to be a position “installation distance (D−M)” from the landing position of the cyan liquid ejection head unit 210C.

  First, the first acquisition timing TS1 at which the black sensor device SENK detects is the timing at which the encoder pulse ENP has reached a predetermined value. The first acquisition timing TS1 is a timing earlier than the timing at which the black liquid discharge head unit 210K discharges liquid by “installation distance D / unit movement amount PD”. Further, at the first acquisition timing TS1, the black sensor device SENK acquires image data. In the illustrated example, the image acquired at the first acquisition timing TS1 is indicated by the first image signal PA. The image data corresponds to the image data D1 (n) at “position A” shown in FIG.

  Next, the apparatus 110 that discharges the liquid turns on the first control signal SIG1 in FIG. 7 so that the black liquid discharge head unit 210K discharges the liquid at the first processing timing TE1. The first processing timing TE1 is also a timing at which the encoder pulse ENP becomes a predetermined value. Note that the first processing timing TE1 may be counted from the first timing T1.

  Next, at the second acquisition timing TS2, the cyan sensor device SENC acquires image data. This second acquisition timing TS2 is the timing after adjustment by the processing shown in FIG. The pre-adjustment timing TBE shown in the figure is an imaging timing by the cyan sensor device SENC when the process shown in FIG. 14 is not performed. In this example, it is found in steps S19 and S20 in FIG. 14 that when the cyan sensor device SENC performs imaging at the timing L, which is the number of encoder pulses ENP between the head units, it is too early for the position to be imaged. Therefore, the timing at which the cyan sensor device images is adjusted after the number of pulses corresponding to ΔL. That is, since the position of the cyan sensor device SENC is shifted toward the cyan liquid ejection head unit 210C by the “mounting error M”, detection is performed after the number of pulses corresponding to ΔL. In the illustrated example, the image acquired at the second acquisition timing TS2 is indicated by the second image signal PB, and the image data corresponds to the image data D2 (n) at the “B position” shown in FIG. Next, the calculation unit 53F of the apparatus 110 that ejects liquid performs a cross-correlation operation on the image data D1 (n) and D2 (n). In this way, the image forming apparatus can calculate the shift amount ΔD (0).

  When the conveyance state is the same as the conveyance at the second moving speed, that is, when the roller has no thermal expansion and there is no slip between the roller and the web 120, the device 110 that discharges the liquid The number of encoder pulses required to move the predetermined position of the web 120 from the black liquid discharge head unit 210K to the cyan liquid discharge head unit 210C is “L”.

  On the other hand, in actuality, when the web 120 is moved at the first movement speed that is faster than the second movement speed, slipping often occurs between the roller and the web 120.

  FIG. 19 is a diagram illustrating an example of the influence of the eccentricity of the roller or the like on the deviation of the landing position. The illustrated graph shows an example of the influence of slippage between the roller and the web, thermal expansion and eccentricity of the roller, and the like. That is, each graph shows the difference between the web position calculated based on the encoder signal from the encoder ENC and the actual position by the “deviation amount” on the vertical axis. The illustrated example shows an example in which the roller has an outer diameter of “φ60” and the roller material is aluminum.

  The third graph G3 shows the amount of deviation when the roller has an eccentric amount “0.01 mm”. As shown by the third graph G3, the amount of deviation due to eccentricity often becomes a period synchronized with the rotation period of the roller. Further, the amount of deviation due to eccentricity is often proportional to the amount of eccentricity, but is often not accumulated.

  The fourth graph G4 shows the amount of deviation when the roller has eccentricity and thermal expansion. The thermal expansion is an example when there is a temperature change of “−10 ° C.”.

  The fifth graph G5 shows the amount of deviation when the roller has eccentricity and slippage generated between the web and the roller. Note that the slip generated between the web and the roller is an example of “0.1%”.

  Further, in order to reduce the meandering of the web, a so-called tension may be applied to pull the web in the conveyance direction. Depending on the tension, the web may stretch or shrink. Further, the expansion and contraction of the web may vary depending on the thickness, width, coating amount, etc. of the web.

  Returning to FIG. 18, based on the image data D2 (n) acquired at the second acquisition timing TS2 and the image data D1 (n) acquired at the first acquisition timing TS1, the calculation unit 53F of the device 110 that ejects liquid. Calculates the deviation amount ΔD (0). Then, the apparatus 110 that ejects the liquid changes the processing timing at which the cyan liquid ejection head unit 210C ejects the liquid, that is, the second processing timing TE2, based on the shift amount ΔD (0) and the unit movement amount PD.

  Actually, after the lapse of the number of pulses of “L”, the cyan liquid discharge head unit 210C discharges the liquid at the position where the liquid discharge head unit 210C discharges the liquid because of thermal expansion or slip of the roller. It is in the position of the amount of deviation ΔD (0) from the position where it does. Therefore, the timing at which the cyan liquid discharge head unit 210C should discharge the liquid is shifted by “ΔD (0) / PD”. Therefore, the apparatus 110 that discharges the liquid changes the processing timing from the pre-change processing timing TE2 ′ to the second processing timing TE2 so that the liquid can be discharged at a position where the deviation amount ΔD (0) is from the ideal position. To do.

  As described above, the apparatus 110 that ejects the liquid shifts the timing at which the second control signal SIG2 is turned “ON” by “ΔD (0) / PD” from the pre-change processing timing TE2 ′ to the second processing timing TE2. change. In this way, even when there is thermal expansion of the roller, slip between the web and the roller, etc., the apparatus 110 that discharges the liquid changes the processing timing based on the shift amount ΔD (0) and the unit movement amount PD. In the transport direction, the accuracy of the liquid landing position can be improved.

  In addition, the ideal moving speed may be set in advance for each mode in the apparatus 110 that ejects liquid. The ideal moving speed is a moving speed in a state where there is no thermal expansion or the like.

  The example in which the processing timing is determined by changing the processing timing based on the encoder pulse ENP has been described above. However, the apparatus 110 that ejects the liquid ejects the liquid based on the shift amount, the moving speed “V”, and the installation distance “D”. The processing timing for discharging the liquid to the head unit may be determined by direct calculation. In addition, a plurality of the above processes may be performed in parallel. That is, in FIG. 18, the acquisition of the image data D1 is performed once, but actually, the acquisition of the image data D1 is performed a plurality of times during the period of FIG. 18, and the position of each image data D1 moves after L + ΔL. The corresponding image data D2 may be acquired.

  <Example of variation in the orthogonal direction of the web being processed>

  FIG. 20 is a diagram illustrating an example in which the position of the recording medium varies in the orthogonal direction. Hereinafter, an example in which the web 120 is conveyed in the conveyance direction 10 as illustrated in FIG. As shown in this example, the web 120 is conveyed by a roller or the like. Thus, when the web 120 is conveyed, the position of the web 120 may fluctuate in the orthogonal direction as shown in FIG. 20B, for example. That is, the web 120 may “meander” as shown.

  In the example shown in the figure, the rollers are arranged obliquely. In the figure, the state of being “oblique” is described in an easy-to-understand manner, and the inclination of the roller or the like may be less than in the illustrated example.

  The variation in the position of the web 120 in the orthogonal direction, that is, “meandering” occurs due to, for example, eccentricity of a roller related to conveyance, misalignment, or cutting of the web 120 by a blade. In addition, when the web 120 is narrow in the orthogonal direction, the thermal expansion of the roller may affect the variation in the position of the web 120 in the orthogonal direction.

  For example, when vibrations occur due to roller eccentricity or blade cutting, the web 120 may “meander” as shown. In addition, the blade 120 may not be evenly cut, and the web 120 may “meander” as illustrated depending on the physical characteristics of the web 120, that is, the shape after the web 120 is cut. is there.

  FIG. 21 is a diagram illustrating an example of a cause of color misregistration. As described with reference to FIG. 20, when the position of the recording medium fluctuates in the orthogonal direction, that is, “meandering” occurs, the following color misregistration is likely to occur.

  Specifically, when an image is formed on a recording medium using a plurality of colors, that is, when a color image is formed, the image forming apparatus discharges each liquid discharge head unit as illustrated. A color image by a so-called color plane is formed on the web 120 by superimposing the inks of the respective colors.

  On the other hand, there is a position variation as described in FIG. For example, “meandering” may occur based on the reference line 320. In this case, when each liquid discharge head unit discharges ink to the same position, the position of the web 120 fluctuates in the orthogonal direction due to “meandering” between the liquid discharge head units. May occur. In other words, the color misalignment 330 occurs when the position of a line or the like formed by the ink ejected by each liquid ejection head unit deviates in the orthogonal direction. As described above, when the color misregistration 330 occurs, the image quality of the image formed on the web 120 may deteriorate.

  <Example of movement of orthogonal position>

  The position in the orthogonal direction, the movement speed, or the first movement amount is obtained from the calculation result of the calculation unit 53F as described above. Detection of the image data D1 and image data D2 to be calculated by the calculation unit 53F is image data similar to the image data used for adjusting the processing timing. That is, the image data is detected at the timing adjusted based on steps S13 to S21 in the flow of FIG.

  FIG. 22 is a block diagram illustrating an example of a moving mechanism for moving a liquid discharge head unit included in a liquid discharge apparatus according to an embodiment of the present invention. The moving mechanism is a hardware configuration example that realizes the function of the moving unit 110F80 shown in FIG. For example, the moving mechanism is realized by hardware as illustrated. The illustrated example is an example of a moving unit that moves the cyan liquid discharge head unit 210C.

  First, in the illustrated example, an actuator ACT such as a linear actuator that moves the cyan liquid discharge head unit 210C is installed in the cyan liquid discharge head unit 210C. The actuator ACT is connected to an actuator controller CTRL that controls the actuator ACT.

  The actuator ACT is, for example, a linear actuator or a motor. Further, the actuator ACT may include a control circuit, a power supply circuit, a mechanical component, and the like.

  The actuator controller CTRL receives a detection result indicating the position, the first movement amount, or the movement speed of the web 120 in the orthogonal direction calculated by the calculation unit 53F. Then, the actuator controller CTRL moves the cyan liquid ejection head unit 210C by the actuator ACT so as to compensate for the variation in the position of the web 120 indicated by the detection result. Instead of the detection result, an instruction signal for driving the actuator, a movement timing, or the like may be input to the actuator controller.

  In the illustrated example, the detection result is, for example, a fluctuation Δ. Therefore, in this example, the actuator controller CTRL moves the cyan liquid ejection head unit 210C in the orthogonal direction 20 so as to compensate for the variation Δ.

  If there is a moving part realized by such a moving mechanism or the like, each liquid discharge head unit can be moved during the process. Therefore, the conveying device can be moved by “meandering” or the like during the process. Even if the angle fluctuates in the orthogonal direction 20, processing can be performed with high accuracy by following the liquid discharge head unit.

  Further, when the data acquisition timing is adjusted, the influence of disturbance such as the attachment error M is reduced. Thus, when the influence of disturbance such as the attachment error M is reduced, for example, as shown in FIG. 16, the detection range in which the detection unit 52B can perform detection can be widened. Further, in the detection range, the detection unit 52B can detect the position of the conveyed object. Thus, when a detection result is obtained in a wide range, the transport device can perform processing with high accuracy by the head unit.

  In addition, the apparatus for ejecting liquid according to the embodiment obtains detection results such as the position in the transport direction, the orthogonal direction, or both of these directions, the movement speed, or the first movement amount for each liquid ejection head unit.

  Therefore, the apparatus for ejecting liquid according to the embodiment can determine the processing timing for ejecting the liquid for each liquid ejection head unit based on the detection result and the like. Therefore, as compared with the above-described comparative example or the like, the apparatus for ejecting liquid according to the embodiment can accurately compensate for the deviation generated at the liquid landing position in the transport direction.

  Furthermore, in the apparatus for ejecting liquid according to the embodiment, since the position of the web can be directly detected, the influence of the thermal expansion of the roller can be canceled with high accuracy. In addition, in the apparatus for ejecting liquid according to an embodiment of the present invention, if detection is performed at a position close to the liquid ejection head unit, the influence of web expansion and contraction can be canceled with high accuracy.

  Thus, when the influence of roller eccentricity, roller thermal expansion, slip generated between the web and the roller, expansion / contraction of the recording medium, and combinations thereof can be reduced, the device for discharging liquid is discharged. The accuracy of the liquid landing position can be further improved.

  In addition, when an image is formed on a recording medium by ejecting a liquid, the apparatus for ejecting the liquid according to the embodiment reduces the color misregistration when the landing positions of the ejected liquids of the respective colors are improved. The quality of the image to be displayed can be improved.

  Furthermore, each detection unit determines the position, moving speed, first moving amount, or a combination of these for each liquid ejection head unit based on patterns that the conveyed object has at two or more different timings. To detect. In this way, since the processing timing at which each liquid discharge head unit discharges the liquid is controlled based on the respective detection results, the apparatus that discharges the liquid can more accurately detect the deviation that occurs at the liquid landing position. Can compensate well.

  In addition to the detection result, when the measurement result by the measurement unit is also used, the apparatus for ejecting the liquid can more reliably detect the position of the recording medium.

  The adjustment is preferably performed at a low speed such as the second movement speed. If it is before adjustment, the acquisition timing is, for example, pre-adjustment timing TBE (FIG. 15). And in order to calculate deviation | shift amount (DELTA) D, if the predetermined location detected on the upstream side is not somewhere in the image data obtained at the pre-adjustment timing TBE, the detection unit 52B will detect the predetermined location. Since it cannot be detected, it is difficult for the deviation amount calculation unit 110F50 to calculate the deviation amount ΔD. On the other hand, if the moving speed is low, there is a high possibility that a predetermined portion detected on the upstream side is captured even in the image data obtained at the pre-adjustment timing TBE. In other words, the device that discharges the liquid is easily adjusted when the second movement speed is set.

<Modification>
Note that the detection unit captures images twice with one sensor, compares the images generated by the respective images, and outputs detection results such as the position of the web 120, the amount of movement, the movement speed, or a combination thereof. May be.

  The embodiment according to the present invention may be realized by a transport system such as a system that ejects liquid having one or more devices. For example, the black liquid discharge head unit 210K and the cyan liquid discharge head unit 210C are apparatuses in the same casing, and the magenta liquid discharge head unit 210M and the yellow liquid discharge head unit 210Y are apparatuses in the same casing, both of which are included. You may implement | achieve by the system which discharges a liquid.

  Further, in the apparatus for ejecting liquid and the system for ejecting liquid according to the present invention, the liquid is not limited to ink, and may be another type of recording liquid or fixing processing liquid. In other words, the apparatus for ejecting liquid and the system for ejecting liquid according to the present invention may be applied to an apparatus for ejecting a liquid of a type other than ink.

  Therefore, the apparatus for ejecting liquid and the system for ejecting liquid according to the present invention are not limited to forming an image. For example, the formed object may be a three-dimensional structure.

  Further, the conveyed object is not limited to a recording medium such as paper. The material to be conveyed may be a material to which a liquid can adhere. For example, the material to which the liquid can be attached is not limited as long as the liquid such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or a combination thereof can be attached temporarily.

  The present invention can also be applied to an apparatus that performs some processing on a transported object using line-shaped head units arranged in a direction orthogonal to the transport direction.

<First Modification>
The first support member and the second support member may be combined. For example, the first support member and the second support member may have the following configurations.

  FIG. 23 is a schematic diagram illustrating a first modification of the apparatus for ejecting liquid according to an embodiment of the present invention. Compared to FIG. 2, the arrangement of the first support member and the second support member is different in the illustrated configuration. As illustrated, the first support member and the second support member may be realized by, for example, the first member RL1, the second member RL2, the third member RL3, the fourth member RL4, and the fifth member RL5. . That is, the second support member provided on the upstream side of each liquid discharge head unit and the first support member provided on the downstream side of each liquid discharge head unit may be combined. Note that the first support member and the second support member may be combined with a roller or a curved plate.

<Second Modification>
For example, the transport device may perform processing such as reading on the transported object as follows.

  FIG. 24 is a schematic diagram illustrating a second modification of the apparatus for ejecting liquid according to an embodiment of the present invention. Hereinafter, as illustrated, a case where the web 120 is conveyed from the upstream side to the downstream side (from left to right in the drawing) will be described as an example.

  As shown in the figure, in this modification, the head unit includes a CIS (Contact Image Sensor) head.

  The head unit is composed of one or more CIS heads installed in the orthogonal direction 20. For example, as illustrated, the transport apparatus includes two head units such as a head unit HD1 and a head unit HD2. The number of head units is not limited to two, and may be three or more.

  As illustrated, each of the head unit HD1 and the head unit HD2 includes one or more CIS heads. Hereinafter, the head unit includes one CIS head. For example, the head unit may include a plurality of CIS heads at positions where the two CIS heads are staggered.

  The head unit HD1 and the head unit HD2 constitute a so-called scanner. Therefore, the head unit HD1 and the head unit HD2 read an image or the like formed on the surface of the web 120, and output image data indicating the read image or the like. The transport device can generate an image connected in the orthogonal direction 20 by connecting the image data output from the head units.

  In this example, the transport device includes a controller 520, a first actuator controller CT1, and a second actuator controller CT2. The controller 520, the first actuator controller CT1, and the second actuator controller CT2 are information processing apparatuses. Specifically, the controller 520, the first actuator controller CT1, and the second actuator controller CT2 have a hardware configuration including an arithmetic device such as a CPU, an electronic circuit, or a combination thereof, a control device, a storage device, an interface, and the like. The controller 520, the first actuator controller CT1, and the second actuator controller CT2 may be a plurality of devices or may be configured by the same device.

  Sensor devices SEN1 and SEN2 are installed for each head unit. And a conveyance apparatus can detect the surface information of the web 120 with a sensor device, and can detect the relative position between a plurality of detection results, a moving speed, a moving amount, or a combination thereof.

  In this example, a plurality of rollers are installed for the two head units HD1 and HD2. As shown in the drawing, the plurality of rollers are installed on the upstream side and the downstream side, respectively, with the two head units HD1 and HD2 interposed therebetween, for example.

  As described above, when the sensor device detects the inter-roller INT, the conveying device can detect the position of the web 120 at a position close to the processing position. Further, the inter-roller INT often has a relatively stable moving speed. Therefore, the transport apparatus can accurately detect the relative position, speed, amount of movement, or a combination thereof among a plurality of detection results in the transport direction, the orthogonal direction, or both directions.

  In addition, the position where the sensor device is installed is preferably a position closer to the first roller R1 than the processing position in the inter-roller INT. That is, it is desirable for the sensor device to perform detection upstream of the processing position. Specifically, in the illustrated example, the sensor device SEN1 is desirably installed at a position closer to the first roller R1 than the processing position where the head unit HD1 performs processing. That is, in the illustrated example, the sensor device SEN1 performs detection in a section between the processing position where the head unit HD1 performs processing and the first roller R1 (hereinafter referred to as “first upstream section INT1”). desirable.

  Similarly, in the illustrated example, the sensor device SEN2 is desirably installed at a position closer to the first roller R1 than the processing position where the head unit HD2 performs processing. That is, in the illustrated example, the sensor device SEN2 performs detection in a section between the processing position where the head unit HD2 performs processing and the first roller R1 (hereinafter referred to as “second upstream section INT2”). desirable.

  When sensor devices are installed in the first upstream section INT1 and the second upstream section INT2, the transport apparatus can detect the position of the object to be transported with high accuracy. When the sensor device is installed at such a position, the sensor device is installed upstream from the processing position. Therefore, the transport apparatus can first detect the surface information of the transported object by the sensor device on the upstream side. Based on the detection result, the transport device can calculate the processing timing by the head unit, the amount by which the head unit is moved, or both in the orthogonal direction, the transport direction, or both directions. That is, since the processing timing is calculated or the head unit is moved while the web 120 is transported to the processing position after the position of the transported object is detected on the upstream side, the transporting device is accurate. The processing position can be changed.

  When the sensor device is installed almost directly below the head unit, processing may be delayed due to processing time calculation or processing time such as moving the head unit. Therefore, if the position where the sensor device is installed is upstream from the processing position, the transport device can reduce delay in processing. Further, the processing position, that is, the vicinity immediately below the head unit may be restricted to a position where a sensor device or the like is installed. Therefore, the position where the sensor device is installed is preferably closer to the first roller R1 than the processing position, that is, upstream from the processing position.

  There is a case where light is emitted from the light source to the web 120 in both the processing by the head unit and the detection by the sensor device. And especially when the transparency of the web 120 is high, each light may become disturbance. Therefore, it may be desirable that the sensor device and the head unit are not on the same optical axis.

  On the other hand, when the transparency of the web 120 is not high, the position where the sensor device is installed may be, for example, directly below the head unit. In the illustrated example, the position immediately below the head unit is the back side of the processing position. That is, in the transport direction, the processing position and the position where the sensor device is installed are substantially the same, and one surface (front side) of the web 120 is a processing target, and the other surface (back surface) of the web 120 is a sensor. In some cases, the device may be a detection target.

  As described above, when the sensor device is directly under the head unit, an accurate movement amount directly under the head unit can be detected by the sensor device. Therefore, it is desirable that the sensor device be in a position close to the position immediately below the head unit if the respective lights are not disturbed and the control or the like can be performed quickly. On the other hand, the sensor device does not have to be almost directly below the head unit, and the same calculation is performed even when the sensor device is not directly below.

  If the error can be tolerated, the position where the sensor device is installed may be a position almost directly below the head unit or between the rollers INT and downstream of the head unit.

<Third Modification>
For example, the apparatus 110 that discharges the liquid may use a belt or the like as the transported object as follows.

  FIG. 25 is a schematic diagram illustrating a third modification of the apparatus for ejecting liquid according to an embodiment of the present invention. In this modification, the head units 350 </ b> C, 350 </ b> M, 350 </ b> Y, and 350 </ b> K eject ink droplets to form an image on the outer peripheral surface of the transfer belt 328. Hereinafter, the head units 350C, 350M, 350Y, and 350K are collectively referred to as a “head unit group 350”.

  Next, the drying mechanism 370 dries the image formed on the transfer belt 328 to form a film.

  Subsequently, in the transfer unit where the transfer belt 328 faces the transfer roller 330, the device 110 that discharges the liquid transfers the filmed image on the transfer belt 328 onto a sheet.

  The cleaning roller 323 cleans the surface of the transfer belt 328 after transfer.

  As described above, in this variation, in the apparatus for ejecting liquid, the head units 350C, 350M, 350Y, and 350K, the drying mechanism 370, the cleaning roller 323, the transfer roller 330, and the like are provided around the transfer belt 328.

  In this modification, the transfer belt 328 is stretched around a drive roller 321, a counter roller 322, four shape maintaining rollers 324, and eight support rollers 325C1, 325C2, 325M1, 325M2, 325Y1, 325Y2, 325K1, and 325K2, etc. It moves in the direction of the arrow in the figure following the drive roller 321 rotated by the transfer belt drive motor 327. The direction in which the transfer belt 328 moves due to the rotation of the driving roller 321 is defined as the moving direction.

  Further, the eight support rollers 325C1, 325C2, 325M1, 325M2, 325Y1, 325Y2, 325K1, and 325K2 provided to face the head unit group 350 are transferred belt 328 when ink droplets are ejected from each head unit 350. Maintain the tensile state of. The transfer motor 331 rotates the transfer roller 330.

  Further, in this modification, the sensor device 332C is disposed between the support roller 325C1 and the support roller 325C2 and on the upstream side in the moving direction of the transfer belt 328 from the ejection position of the head unit 350C. Further, the sensor device 332C includes a speckle sensor.

  The speckle sensor is an example of a sensor that acquires information on the transfer belt 328. Further, the sensor device 332M is also provided for the head unit 350M in the same positional relationship as the positional relationship of the support roller 325C1, the support roller 325C2, and the sensor device 332C with respect to the head unit 350C.

  In this modification, actuators 333M, 333Y, and 333K are provided in the head unit M, the head unit Y, and the head unit K, respectively. The actuator 333M is an actuator that moves the head unit M in a direction orthogonal to the moving direction of the transfer belt 328. Similarly, the actuators 333Y and 333K are actuators that move the head unit 350Y and the head unit 350K in directions orthogonal to the moving direction of the transfer belt 328, respectively.

  The control board 340 detects the movement amount of the transfer belt 328 in the orthogonal direction, the movement amount of the transfer belt 328 in the movement direction, and the like based on the image data acquired from the sensor devices 332C, 332M, 332Y, and 332K. The control board 340 controls the actuators 333M, 333Y, and 333K according to the amount of movement of the transfer belt 328 in the orthogonal direction, and moves the head units 350M, 350Y, and 350K in the orthogonal direction. Further, the control substrate 340 controls the ejection timing of the head units 350M, 350Y, and 350K according to the movement amount of the transfer belt 328 in the movement direction.

  Further, the control board 340 outputs drive signals to the transfer belt drive motor 327 and the transfer motor 331.

<Effect in the third modification>
According to this modification, even when the transfer belt 328 moves in the orthogonal direction perpendicular to the movement direction driven by the drive roller 321 during the movement of the transfer belt 328, the liquid is discharged according to the detected movement amount. The apparatus 110 that can move the head units 350M, 350Y, and 350K in the orthogonal directions. For this reason, the apparatus 110 that ejects liquid can form a high-quality image on the transfer belt 328.

  Further, even when the transfer belt 328 moves in a moving direction different from the assumed movement direction in the driving direction of the driving roller 321, the apparatus 110 that discharges the liquid according to the detected moving amount is used for the head units 350M, 350Y, and 350K. The discharge timing can be changed. For this reason, the apparatus 110 that ejects liquid can form a high-quality image on the transfer belt 328.

  In the above example, the movement amount in the orthogonal direction of the transfer belt 328 and the movement amount in the movement direction of the transfer belt 328 are calculated based on the image data acquired from the sensor devices 332C, 332M, 332Y, and 332K. When only such a movement amount is used, only one of the movement amounts may be calculated.

  In this modification, the head unit 350C does not include an actuator, but may include it. Then, by moving the head unit 350C in the orthogonal direction, it is possible to control the position in the direction orthogonal to the transfer direction of the transfer P when the image is transferred from the transfer belt 328 to the sheet.

  In the above example, an example in which an image is formed on the transfer belt 328 using a plurality of head units has been described. However, the present invention can also be applied to the case where an image is formed by one head unit.

  Further, for example, the embodiment according to the present invention may be a transport device that performs patterning processing on a substrate, which is a transported object, by the head unit emitting laser. Specifically, the transport apparatus first has laser heads arranged in a line in a direction orthogonal to the transport direction in which the substrate is transported. The transfer device detects the position of the substrate and moves the head unit based on the detection result. In this example, the processing position is the processing position at which the laser is irradiated on the substrate.

  Further, the transport device does not have to have a plurality of head units. That is, the present invention can be applied to a case where processing is continued at a reference position with respect to an object to be conveyed.

  Further, in the embodiment according to the present invention, it is realized by a program for causing a computer to execute part or all of the timing adjustment method such as causing a computer to discharge liquid such as a transport device, an information processing device, or a combination thereof. Also good.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to such specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Or it can be changed.

110 Liquid Discharge Device 120 Web 210K Black Liquid Discharge Head Unit 210C Cyan Liquid Discharge Head Unit 210M Magenta Liquid Discharge Head Unit 210Y Yellow Liquid Discharge Head Unit SENK Black Sensor Device SENC Cyan Sensor Device SENM Magenta Sensor Device SENY For Yellow Sensor device 520 controller

Japanese Patent Laying-Open No. 2015-13476

Claims (16)

A transport apparatus that has a head unit and performs processing by the head unit for a transported object transported at a first moving speed,
A sensor that is installed corresponding to the head unit and acquires information of the conveyed object;
A calculation unit for detecting a detection result indicating a position, a moving speed, a first moving amount, or a combination of these, based on information acquired by the sensor;
A measuring unit for measuring a second movement amount by which the conveyed object moves;
Based on the detection result and the second movement amount when the transported object is transported at a second moving speed that is lower than the first moving speed, the transported object is moved at the first moving speed. An adjustment unit that adjusts an acquisition timing of the information used for detection of a detection result by the calculation unit when being conveyed. The measuring unit is an encoder installed on a roller that conveys the object to be conveyed,
The transport apparatus according to claim 1, wherein the second movement amount is a pulse output from the encoder.   The deviation amount calculation part which calculates the deviation | shift amount from a reference value based on the said detection result by the information obtained at the said acquisition timing determined based on the said 2nd movement amount is further provided. The transfer apparatus according to any one of the above. The deviation amount calculation unit calculates a plurality of deviation amounts, and calculates an average value based on the plurality of deviation amounts,
The said adjustment part adjusts based on the said average value, The conveying apparatus of Claim 3 characterized by the above-mentioned. A first support member provided on an upstream side in a transport direction in which the transported object is transported from a processing position where the head unit performs the processing on a predetermined portion of the transported object;
A second support member provided downstream of the processing position in the transport direction,
5. The transport device according to claim 1, wherein the sensor is provided between the first support member and the second support member. 6.   The transport apparatus according to claim 5, wherein the sensor is installed at a position closer to the first support member than the processing position.   The transport apparatus according to claim 1, wherein the sensor is an optical sensor.   The transport apparatus according to claim 1, wherein the calculation unit obtains the detection result based on a pattern of the transported object.   The calculation unit may calculate the position, the movement speed, the first movement amount, or a combination thereof based on the patterns acquired at two or more timings at which at least one timing is adjusted by the adjustment unit. The transport device according to claim 8, wherein the transport device is detected. The pattern is generated by interference of light applied to the uneven shape formed on the transported object,
The transport device according to claim 8, wherein the calculation unit obtains the detection result based on an image obtained by capturing the pattern.   11. The transport apparatus according to claim 1, wherein an image is formed on the transported object when the processing is performed.   The transport apparatus according to claim 1, wherein the object to be transported is a sheet that is continuously long along a transport direction. A control unit that causes the head unit to perform the processing based on the detection result with respect to the object to be conveyed at the first movement speed;
The said control part produces | generates each process timing with which the said head unit performs the said process based on the said detection result with respect to the to-be-conveyed object conveyed with a 1st moving speed. The transfer device according to any one of 12.   The transport apparatus according to claim 13, wherein the control unit causes the head unit to perform the processing based on the second movement amount and the detection result. A transport system having a head unit and having at least one device for processing a transported object transported at a first moving speed by the head unit;
A sensor that is installed corresponding to the head unit and acquires information of the conveyed object;
A calculation unit for detecting a detection result indicating a position, a moving speed, a first moving amount, or a combination of these, based on information acquired by the sensor;
A measuring unit for measuring a second movement amount by which the conveyed object moves;
The transported object is transported at the first moving speed based on the detection result and the second moving amount when the transported object moves at a second moving speed that is lower than the first moving speed. An adjustment unit that adjusts an acquisition timing of the information used for detection of a detection result by the calculation unit. A timing adjustment method that is performed by an apparatus that has a head unit and performs processing by the head unit on an object to be conveyed at a first movement speed,
A detection procedure in which the apparatus outputs a detection result indicating the position, movement speed, first movement amount, or combination thereof of the object to be conveyed based on information acquired by a sensor installed corresponding to the head unit. When,
A measurement procedure in which the apparatus measures a second movement amount by which the conveyed object moves; and
An adjustment procedure in which the apparatus adjusts an acquisition timing of the information to be detected in the detection procedure when the object is conveyed at the first movement speed based on the detection result and the second movement amount. A timing adjustment method comprising:

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