JP2019006096A - Liquid discharge device, method and system - Google Patents

Abstract

To provide a liquid discharge device capable of detecting at high accuracy, the position of a material to be transported or the like in a transport direction or the direction orthogonal thereto.SOLUTION: A liquid discharge device having liquid discharge head units 210K, 210C, 210M and 210Y includes: light sources LGY1, LGY2, LGM1, LGM2, LGC1, LGC2, LGIR1, LGIR2 which irradiate a material to be transported with a light having high relative intensity in a wavelength region high in liquid relative reflectance; and optical sensors OS2, OS3, OS4 and OS5 imaging the material to be transported irradiated with light. Besides, the device is equipped with a transported material detection unit which detects at least either one of the transport amount or speed of the transported material on the basis of the generated image data.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an apparatus for ejecting liquid, a method for ejecting liquid, and a system for ejecting liquid.

  2. Description of the Related Art Conventionally, a method for 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, in order to further improve the image quality of an image to be formed, the direction in which the object is transported (hereinafter referred to as “transport direction”) or the direction orthogonal to the transport direction (hereinafter simply referred to as “orthogonal direction”). In other words, the position of the object to be transported may be required to be detected with high accuracy in order to improve the position where the liquid is landed. On the other hand, in the conventional technology, there is a problem that the position or the like of the object to be transported may not be accurately detected in the transport direction or the orthogonal direction.

  An object of one aspect of the present invention is to provide an apparatus for ejecting a liquid that accurately detects the position of an object to be transported in a transport direction or an orthogonal direction.

In order to solve the above-described problem, an apparatus for ejecting liquid having a liquid ejection head unit that ejects liquid, which is one embodiment of the present invention,
A light source for irradiating the object with light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high relative reflectance of the liquid;
And a detection unit configured to detect at least one of a movement amount and a movement speed of the object to be transported based on image data generated by imaging the portion irradiated with the light.

  It is possible to provide a device that ejects a liquid that can accurately detect the position or the like of a transported object in the transport direction or the orthogonal direction.

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 a schematic diagram which shows the example of arrangement | positioning of the sensor device in 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 figure which shows an example of the spectral reflectance characteristic of the yellow ink which concerns on one Embodiment of this invention. It is a figure which shows an example of the spectral intensity characteristic of the yellow light source which concerns on one Embodiment of this invention. It is a figure which shows an example of the spectral reflectance characteristic of the magenta ink which concerns on one Embodiment of this invention. It is a figure which shows an example of the spectral intensity characteristic of the red light source which concerns on one Embodiment of this invention. It is a figure which shows an example of the spectral reflectance characteristic of the cyan ink which concerns on one Embodiment of this invention. It is a figure which shows an example of the spectral intensity characteristic of the blue light source which concerns on one Embodiment of this invention. It is a block diagram which shows the hardware structural example which implement | achieves the to-be-conveyed object detection apparatus 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 a function structure using the to-be-conveyed object detection apparatus 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 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 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 an example of the process by the conveyed product detection apparatus which concerns on one Embodiment of this invention. It is a figure which shows an example of 1st image data and 2nd image data acquired by the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is a figure which shows an example of a function structure of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is the schematic which shows the 1st modification of the whole structure 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 whole structure 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 whole structure of the apparatus which discharges the liquid which concerns on one Embodiment of this invention. It is a figure which shows the modification of a detection and control by the apparatus which discharges the liquid which concerns on the 3rd modification of this invention. It is a timing chart which shows the modification of the detection and control by the apparatus which discharges the liquid which concerns on the 3rd modification of this invention. It is a block diagram which shows the modification of the hardware constitutions which implement | achieve the to-be-conveyed object detection apparatus which concerns on one Embodiment of this invention. It is a figure which shows the 1st modification of the optical sensor which concerns on one Embodiment of this invention. It is a figure which shows the 2nd modification of the optical sensor which concerns on one Embodiment of this invention. It is the schematic which shows an example of the some imaging lens used for the optical sensor 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>
FIG. 1 is a schematic view showing an example of an apparatus for ejecting liquid according to an embodiment of the present invention. For example, an apparatus for ejecting liquid is an image forming apparatus as illustrated. In such an image forming apparatus, the discharged liquid is a recording liquid such as aqueous or oil-based ink. Hereinafter, an example in which the apparatus for ejecting liquid is the image forming apparatus 110 will be described.

  The conveyed object is, for example, a recording medium. In the illustrated example, the image forming apparatus 110 forms an image by ejecting liquid onto a web 120 that is an example of a recording medium conveyed by a roller 130 or the like. The web 120 is a so-called continuous paper printing medium or the like. That is, the web 120 is roll-shaped paper or the like that can be wound. As described above, the image forming apparatus 110 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 an example of the orthogonal direction 20. Hereinafter, the image forming apparatus 110 ejects each of the four colors of black (K), cyan (C), magenta (M), and yellow (Y) to form an image on a predetermined portion of the web 120. An example of a printer will be described.

  FIG. 2 is a schematic diagram illustrating an arrangement example of sensor devices in the apparatus for ejecting liquid according to the embodiment of the present invention. For example, the image forming apparatus 110 includes a sensor device that detects the position of the web 120 at the illustrated position.

  Each sensor device is disposed near an end in the width direction of the web 120 (that is, the orthogonal direction 20) when viewed from a direction perpendicular to the recording surface of the web 120, and It is desirable to arrange in an overlapping position. Specifically, in the illustrated example, each sensor device is arranged at an arrangement position PS1, PS2, PS3, PS4, PS5, or the like.

  That is, sensor devices (SN1, SN2, SN3, SN4, SN5) are installed along the conveyance path of the web 120, respectively.

  Each sensor device includes a light source that irradiates the web 120 with light such as laser light, and a sensor that captures an area irradiated from the light source. In this configuration, the controller 520 controls the actuators AC1, AC2, AC3, and AC4, so that the image forming apparatus 110 can move each liquid ejection head unit in the orthogonal direction 20.

  In addition, the controller 520 connected to each liquid ejection head unit controls the timing at which each liquid ejection head unit performs ejection. Control and movement are not performed by the controller 520 but may be performed by two or more controllers or circuits. The actuator will be described later.

  As shown in the drawing, each sensor device is provided on the same side (the side where each liquid discharge head unit is installed with respect to the web 120) where each liquid discharge head unit performs processing.

  Since the scattered light scattered from the surface of the web 120 overlaps and interferes with the laser light emitted from the light source, a pattern such as a speckle pattern is generated. And the optical sensor which each sensor device has images such a pattern, and produces | generates image data. Thus, based on the change in the position of the pattern imaged by the optical sensor, for example, the image forming apparatus 110 can calculate the amount of movement for moving each liquid ejection head unit, the ejection timing of each liquid ejection head unit, or both. .

  Further, in the illustrated configuration, each liquid ejection head unit and each sensor device has at least one image forming area where each liquid ejection head unit forms an image and each detection area where each sensor detects. You may arrange | position so that a part may overlap.

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

  As shown in the drawing, it is desirable that the color order that absorbs light like black is the most downstream as shown in the figure. Therefore, the order of yellow (Y), magenta (M), and cyan (C) is not limited to the order shown. For example, the color order may be yellow (Y), cyan (C), magenta (M), and black (K).

  FIG. 3 is a schematic diagram illustrating an example of the overall configuration of an apparatus for ejecting liquid according to an embodiment of the present invention. As shown in the figure, the image forming apparatus 110 includes four liquid discharge head units for discharging each of the four ink colors.

  Each liquid discharge head unit discharges each color ink to a predetermined portion of the web 120 based on image data or the like. As described above, the position at which each liquid discharge head unit discharges ink (hereinafter referred to as “discharge position”) is substantially equal to the position at which the ink discharged from the liquid discharge head unit lands on the web 120. That is, the discharge position is almost directly below the liquid discharge head unit. In this example, black ink is ejected to the ejection position of the black liquid ejection head unit 210K (hereinafter referred to as “black ejection position PK”). Similarly, cyan ink is ejected to the ejection position of the cyan liquid ejection head unit 210C (hereinafter referred to as “cyan ejection position PC”). Further, the magenta ink is ejected to the ejection position of the magenta liquid ejection head unit 210M (hereinafter referred to as “magenta ejection position PM”). The yellow ink is ejected to the ejection position of the yellow liquid ejection head unit 210Y (hereinafter referred to as “yellow ejection position PY”).

  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.

  The recording medium 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. In other words, the recording medium may be paper that is folded and stored, so-called “Z paper” or the like.

  In FIG. 3, the sensor devices SN1, SN2, SN3, SN4 and SN5 are optical sensors (OS1, OS2, OS3, OS4, OS5) and light sources (LGY1, LGY2, LGM1, LGM2, LGC1, LGC2, LGIR1, LGIR2). The optical sensor is, for example, a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera. That is, the optical sensor is, for example, a sensor that can detect the surface of the web 120. The optical sensor is a sensor that can detect the surface of the web 120 during image formation, as will be described later.

  As shown in FIG. 3, the optical sensor OS1, the optical sensor OS2, the optical sensor OS3, the optical sensor OS4, and the optical sensor OS5 are installed so as to sandwich the liquid ejection head unit. As shown in the figure, it is desirable that the optical sensors be installed at intervals of equal intervals INTS. Thus, if each optical sensor is installed at equal intervals INTS, calculation using the values of equal intervals INTS can be facilitated. Each optical sensor is not limited to being installed at equal intervals INTS. That is, each optical sensor may be installed at a position where the interval between the sensors is installed in advance, with the liquid ejection head unit interposed therebetween.

  And sensor device SN1, SN2, SN3, SN4, and SN5 have a light source which irradiates light in the position which each optical sensor senses so that it may illustrate. In the illustrated example, a light source LGY1 that emits yellow light is installed for the sensor device SN1. Similarly, a light source LGY2 that emits yellow light is installed for the sensor device SN2. That is, the sensor device SN1 installed upstream of the yellow liquid ejection head unit 210Y and the sensor device SN2 installed downstream of the yellow liquid ejection head unit 210Y are relatively reflected by the yellow ink ejected by the yellow liquid ejection head unit 210Y. A light source that emits light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high rate;

  Similarly, in the illustrated example, a light source LGM1 that emits magenta light is installed for the sensor device SN2. Further, a light source LGM2 that emits magenta light is installed for the sensor device SN3. That is, the sensor device SN2 installed upstream of the magenta liquid ejection head unit 210M and the sensor device SN3 installed downstream of the magenta liquid ejection head unit 210M are relatively reflected by the magenta ink ejected by the magenta liquid ejection head unit 210M. A light source that emits light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high rate;

  In the illustrated example, a light source LGC1 that emits cyan light is installed for the sensor device SN3. Further, a light source LGC2 that emits cyan light is installed for the sensor device SN4. That is, the sensor device SN3 installed upstream of the cyan liquid ejection head unit 210C and the sensor device SN4 installed downstream of the cyan liquid ejection head unit 210C are relatively reflected by cyan ink ejected by the cyan liquid ejection head unit 210C. A light source that emits light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high rate;

  Further, in the illustrated example, a light source LGIR1 that emits infrared light is installed for the sensor device SN4. Further, a light source LGIR2 that emits infrared light is installed for the sensor device SN5. That is, the sensor device SN4 installed upstream of the black liquid ejection head unit 210K and the sensor device SN5 installed downstream of the black liquid ejection head unit 210K are relatively reflected by the black ink ejected by the black liquid ejection head unit 210K. A light source that emits light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high rate;

  FIG. 4 is a diagram showing an example of the outer shape of the liquid discharge head unit according to the embodiment of the present invention.

  An example of the outer shape of the liquid discharge head unit will be described with reference to FIG. First, FIG. 4A is a schematic plan view showing an example of four liquid discharge head units 210Y to 210K of the image forming apparatus 110 according to the embodiment of the present invention.

  As shown in FIG. 4A, the liquid discharge head unit is a line-type head unit in the present embodiment.

  In this configuration, the black liquid discharge head unit 210K has four heads 210K-1, 210K-2, 210K-3, and 210K-4 arranged in a staggered pattern in the orthogonal direction 20. Each head has a configuration as shown in FIG. 4B, for example. Thereby, the image forming apparatus 110 can form an image in the entire area in the width direction (that is, the orthogonal direction 20) of the image forming area (printing area) of the web 120. The configuration of the other liquid discharge head units 210C, 210M, and 210Y is the same as the configuration of the black liquid discharge head unit 210K, and thus the description thereof is omitted.

  As described above, in the above description, 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.

  FIG. 5 is a diagram illustrating an example of spectral reflectance characteristics of yellow ink according to an embodiment of the present invention. In the figure, the horizontal axis represents wavelength, and the vertical axis represents the relative reflectance of yellow ink for each wavelength.

  As shown in the figure, in this example, the yellow ink has a high relative reflectance with respect to light having a wavelength longer than about 500 nanometers. That is, yellow ink has a characteristic of well reflecting light having a wavelength longer than 500 nanometers. For ink having such characteristics, for example, a yellow light source having the following spectral intensity characteristics is used.

  FIG. 6 is a diagram showing an example of spectral intensity characteristics of a yellow light source according to an embodiment of the present invention. In the figure, the horizontal axis is the wavelength, and the vertical axis is the relative intensity of the light source. Specifically, the yellow light source is, for example, a yellow fluorescent LED (Light Emitting Diode). As illustrated, the yellow light source is a light source that emits light having a high relative intensity in a wavelength band longer than 500 nanometers.

  The magenta ink is a color material having the following characteristics, for example.

  FIG. 7 is a diagram illustrating an example of spectral reflectance characteristics of magenta ink according to an embodiment of the present invention. In the figure, the horizontal axis is the wavelength, and the vertical axis is the relative reflectance of the magenta ink for each wavelength.

  As shown in the figure, in this example, the magenta ink has a peak in the vicinity of about 420 nanometers, and further has a characteristic of high relative reflectance with respect to light having a wavelength longer than about 620 nanometers. That is, magenta ink has a characteristic of well reflecting light having a wavelength longer than 620 nanometers. For the ink having such characteristics, for example, a magenta light source having a spectral intensity characteristic of irradiating light having a high relative intensity in a wavelength band longer than 620 nanometers is used.

  The light source used may be a light source that emits light having a high relative intensity. For yellow ink and magenta ink having the characteristics shown in FIGS. 5 and 7, for example, the following characteristics may be used. A red LED or the like may be used as the light source.

  FIG. 8 is a diagram illustrating an example of spectral intensity characteristics of a red light source according to an embodiment of the present invention. In the figure, the horizontal axis is the wavelength, and the vertical axis is the relative intensity of the light source. As shown in the figure, in this example, the red light source is a light source having a spectral intensity characteristic in which the relative intensity peak is about 650 nanometers. That is, the red light source is a light source that irradiates light with high relative intensity to both yellow and magenta inks having the characteristics shown in FIGS. 5 and 7. Such a light source may be used for a yellow light source and a magenta light source, respectively.

  Cyan ink is a color material having the following characteristics, for example.

  FIG. 9 is a diagram illustrating an example of spectral reflectance characteristics of cyan ink according to an embodiment of the present invention. In the figure, the horizontal axis represents the wavelength, and the vertical axis represents the relative reflectance of cyan ink for each wavelength. As shown in the figure, in this example, the cyan ink has a characteristic having a peak in the vicinity of about 450 nanometers.

  For such cyan ink, for example, a blue LED or the like having the following characteristics may be used as the light source.

  FIG. 10 is a diagram illustrating an example of spectral intensity characteristics of a blue light source according to an embodiment of the present invention. In the figure, the horizontal axis is the wavelength, and the vertical axis is the relative intensity of the light source. As shown in the figure, in this example, the blue light source is a light source having a spectral intensity characteristic in which the relative intensity peak is about 480 nanometers. That is, the blue light source is a light source that irradiates light having a high relative intensity with respect to the ink having the characteristics shown in FIG. Such a light source is used for each of the cyan light sources.

  When the liquid and the light source have the above characteristics, light that is easily reflected by the liquid can be used. In the above example, a light source having a high relative intensity in a wavelength region where the relative reflectance of each ink is close to the peak is used, but the present invention is not limited to this. For example, if the region having the lowest reflectance of the ink in the visible wavelength range is 0% and the region having the highest reflectance is 100%, the light source has a high relative intensity in the region having a reflectance of at least 30% or more. good. It is even better if the light source has a high relative intensity in a region having a reflectance of 50% or more. Furthermore, it is better that the light source has a high relative intensity in a region having a reflectance of 80% or more.

  In the example shown in FIG. 3, the sensor device SN5 may be configured not to be installed. In this configuration, for example, the apparatus that ejects the liquid may predict the position or speed of the black liquid ejection head unit 210K based on the calculation result using the sensor device SN3 and the sensor device SN4. In addition, in this configuration, for example, a configuration in which sensing is performed twice by the sensor device SN4 to replace the sensor device SN5 may be used.

  In the following description, “position where the sensor is installed” refers to a position where detection or the like is performed. Therefore, it is not necessary to install all devices used for detection or the like at the “position where the sensor is installed”, and devices other than the sensor may be installed at other positions that are connected by a cable or the like.

  Furthermore, in the following description, each sensor device (SN1, SN2, SN3, SN4, SN5) may be simply referred to as “sensor device SN”. Similarly, each optical sensor (OS1, OS2, OS3, OS4, OS5) is simply described as “optical sensor OS”, and each light source (LGY1, LGY2, LGM1, LGM2, LGC1, LGC2, LGIR1, LGIR2) is generally described. Sometimes simply described as “light source LG”.

  In FIG. 3, each sensor device is installed at a position for irradiating and sensing the surface of the web 120, that is, the surface on which ink is ejected. You may install in the position which irradiates and senses the surface different from the surface, ie, a back surface.

  FIG. 11 is a block diagram illustrating an example of a hardware configuration that implements a transported object detection device according to an embodiment of the present invention. For example, the transported object detection device 600 as an example of the transported object detection unit is realized by hardware such as the sensor device SN, the storage device 53, and the controller 520 as illustrated.

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

FIG. 12 is an external view showing an example of a sensor device according to an embodiment of the present invention.
First, the sensor device SN includes a semiconductor laser light source (LD) as an example of the light source LG. In the illustrated example, one light source LG is provided, but the sensor device SN may include two or more light sources LG.

  The sensor device SN has an optical system such as a collimating optical system (CL). The sensor device SN captures a pattern or the like to obtain image data, and thus a CMOS image sensor which is an example of an optical sensor OS and a telecentric imaging optical system for condensing and forming a speckle pattern on the CMOS image sensor. (TO).

  In the illustrated example, a CMOS image sensor captures a pattern and obtains image data. And the to-be-conveyed object detection apparatus performs a correlation calculation between the image data imaged by another sensor device and the image data imaged by itself. For example, the correlation calculation is performed by the controller 520. Next, based on the movement of the correlation peak position calculated by correlation calculation or the like, the controller 520 moves the object to be conveyed from the position where one sensor device is installed to the position where the other sensor device is installed. Outputs the amount of movement. In the illustrated example, the size of the sensor device is an example in which width W × depth D × height H is 15 × 60 × 32 [mm]. Details of the correlation calculation will be described later.

  The CMOS image sensor is an example of hardware that realizes an imaging unit.

  In this configuration, the hardware for performing the correlation calculation is the controller 520, but the correlation calculation may be executed by the control circuit 52 mounted on any sensor device.

  The control circuit 52 controls the optical sensor OS and the like. Specifically, for example, the control circuit 52 outputs a trigger signal to the optical sensor OS, and controls the timing at which the optical sensor OS releases the shutter. Further, the control circuit 52 performs control so that two-dimensional image data can be acquired from the optical sensor OS. Then, the control circuit 52 picks up an image of the optical sensor OS and sends the generated two-dimensional image data to the storage device 53 or the like. The control circuit 52 may be, for example, an external FPGA (Field-Programmable Gate Array) connected to the sensor device SN.

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

  The controller 520 performs calculation and control for realizing various processes using image data and the like 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 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. The control circuit 52 and the controller 520 may be a single FPGA circuit or the like.

  FIG. 13 is a functional block diagram illustrating an example of a functional configuration using the conveyed object detection device according to the embodiment of the present invention. Hereinafter, as illustrated, a combination of the sensor device SN1 and the sensor device SN2 arranged on the upstream side and the downstream side of the yellow liquid discharge head unit 210Y in the sensor device SN will be described as an example. Further, as illustrated, the detection unit 52A that is a detection function included in the sensor device SN1 outputs a detection result related to the “A position”, and the detection unit 52B that is a detection function included in the sensor device SN2 is “B position”. An example of outputting a detection result related to "" will be described. First, the detection unit 52A 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 has the same configuration as the detection unit 52A, for example, 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 control unit 14A includes a shutter control unit 141A and an image capturing unit 142A. Note that the imaging control unit 14A is realized by, for example, the control circuit 52 or the like.

  The image capturing unit 142A acquires image data 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 data captured by the imaging control unit 14A. The image storage unit 15A is realized by the storage device 53, for example.

  Based on the respective image data stored in the image storage unit 15A and the image storage unit 15B, the calculation unit 53F moves the relative position of the web 120 between the sensor devices SN, the position of the pattern included in the web 120, and the movement of the web 120. The moving speed, the moving amount of the web 120, or a combination thereof can be calculated.

  Further, the calculation unit 53F outputs data of the time difference Δt indicating the timing of releasing the shutter to the shutter control unit 141A. That is, the calculation unit 53F outputs the shutter release timing to the shutter control unit 141A so that the image data indicating the “A position” and the image data indicating the “B position” are captured with a time difference Δt. . Further, the calculation unit 53F may control a motor or the like that conveys the web 120 so as to achieve the calculated moving speed. Note that the calculation unit 53F is realized by, for example, the controller 520 or the like.

  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, image data indicating a pattern is obtained. As described above, since the position where the pattern exists is known from the image data, the detection unit can detect where the predetermined position of the web 120 is. The pattern is generated because the irradiated laser beam interferes with the uneven shape formed on the surface or inside of the web 120.

  Therefore, when the web 120 is conveyed, the pattern of the web 120 is also conveyed. Therefore, when the same pattern is detected at different times, the calculation unit 53F can calculate the movement amount in the transport direction 10. That is, when the same pattern is detected and the movement amount of the pattern is output, the calculation unit 53F can calculate the movement amount in the transport direction 10. When the movement amount calculated in this way is converted per unit time, the calculation unit 53F can calculate the movement speed in the transport direction 10.

  In this example, the imaging unit 16 </ b> A and the imaging unit 16 </ b> B are installed at regular 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.

  Assuming that the time difference is Δt, the shutter control unit 141A causes the imaging unit 16A to image the web 120 at intervals of the time difference Δt. The calculation unit 53F calculates the movement amount of the web 120 based on the pattern indicated by the image data captured in this manner. Specifically, assuming that the moving speed in an ideal state with no deviation or the like is V [mm / s] and the imaging unit 16A and the imaging unit 16B are installed at a relative distance L [mm] in the transport direction 10, it is ideal. In the state, the interval at which the shutter is released at the “B position” after the shutter is released at the “A position”, that is, the time difference Δt is set as the following equation (1).

Δt = L / V (1)

In the above equation (1), the relative distance L [mm] is an interval between the imaging unit 16A and the imaging unit 16B, and can be specified in advance by measurement or the like.

  The calculation unit 53F performs a cross-correlation operation on the image data D1 (n) and D2 (n) indicating the respective image data captured by the detection units 52A and 52B. Hereinafter, the image data generated by the cross-correlation calculation is referred to as “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 (2).

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

In the above equation (2), the image data D1 (n), that is, the image data captured at the “position A” is “D1”. Similarly, in the above equation (2), the image data D2 (n), that is, the image data captured at the “B position” is “D2”. Furthermore, in the above equation (2), the Fourier transform is indicated by “F []”, and the inverse Fourier transform is indicated by “F-1 []”. Furthermore, in the above equation (2), the complex conjugate is indicated by “*” and the cross-correlation operation is indicated by “★”.

  As shown in the above equation (2), 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 (3).

D1 * D2 * = F-1 [P [F [D1]] · P [F [D2] *]] (3)

In the above equation (3), “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.

  Based on the result of the correlation calculation, information such as a position difference, a moving amount, a moving speed, or a combination thereof between the image data D1 imaged at the time difference Δt and the image data D2 is output. For example, in the orthogonal direction, the calculation unit 53F can calculate how much the web 120 has moved in the orthogonal direction from when the image data D1 is captured until the image data D2 is captured. Note that the calculation unit 53F may calculate not only the movement amount but also the movement speed in the orthogonal direction.

  In this configuration, the yellow liquid discharge head unit 210Y is located between the sensor device SN1 and the sensor device SN2. Since the positional relationship in the transport direction 10 between each sensor device and each liquid ejection head unit is known, the calculation unit 53F moves the liquid ejection head unit from the calculation result based on the image data D1 and D2. The amount of movement can be calculated. And based on the calculation result by the calculation part 53F, the control part 54F can control actuator AC1 and can control the position where a liquid lands.

  Furthermore, the calculation unit 53F can calculate how much the moving amount of the web 120 is deviated from the relative distance L in the transport direction 10 based on the result of the correlation calculation. That is, from the two-dimensional image data captured by the imaging units 16A and 16B, the calculation unit 53F may be used to detect the position and the like in both the transport direction and the orthogonal direction. When used in this way, the cost of installing the sensor device in each direction can be reduced. In addition, since the number of sensor devices can be reduced, space can be saved.

  Based on how much the movement amount deviates from the movement amount in the ideal state, the calculation unit 53F calculates the discharge timing of the yellow liquid discharge head unit 210Y. And based on the calculation result by the calculation part 53F, the control part 54F controls the timing at which discharge is performed by the yellow liquid discharge head unit. Specifically, the processing timing for discharging the liquid is controlled by the signal SIG1 for the yellow liquid discharge head unit 210Y output from the control unit 54F. Note that the control unit 54F is realized by, for example, the controller 520 or the like.

<Example of correlation calculation>
FIG. 14 is a configuration diagram showing an example of a correlation calculation method according to an embodiment of the present invention. For example, the calculation unit 53F can output a detection result indicating the relative position of the web at the sensor position, the moving amount, the moving speed, a combination thereof, or the like when performing the correlation calculation with the configuration as illustrated.

  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. 15 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 conveyance direction in the correlation image data. On the other hand, the vertical axis indicates the luminance of the pixel 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 part SR calculates each difference of the brightness | luminance of the pixel which correlation image data shows. 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. 16 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.

<Example of misalignment>
FIG. 17 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 transported in the transport 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 vary in the orthogonal direction as shown in FIG. 17B, for example. That is, the web 120 may “meander” as shown in FIG.

  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.

  FIG. 18 is a diagram illustrating an example of a cause of color misregistration. As will be described with reference to FIG. 17, when the position of the recording medium fluctuates in the orthogonal direction, that is, “meandering” occurs, color misregistration is likely to occur due to the cause shown in FIG.

  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. That is, the color misalignment 330 occurs because the line formed by the ink ejected by each liquid ejection head unit is misaligned 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 control unit>
The controller 520 (FIG. 2), which is an example of the control unit, has a configuration described below, for example.

  FIG. 19 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 main body side control device 72. In the illustrated example, the controller 520 causes an image to be formed on the recording medium based on the control of the main body side control device 72 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 main body side control 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 main body side control 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. 20 is a block diagram illustrating an example of a hardware configuration of a data management device included in a control unit according to an 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. 15).

  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. 21 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. 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.

  Note that the main body side control device 72 has different paths for inputting image data from the host device 71 and paths used for transmission / reception between the host device 71 and the main body side control device 72 based on the control data. .

  The conveyance control device 72Ec is a driver circuit or the like connected to a motor 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.

<Example of overall processing>
FIG. 22 is a flowchart illustrating an example of processing by the conveyed object detection device according to an embodiment of the present invention. For example, the transported object detection device performs the following process for each liquid ejection head unit. Hereinafter, the yellow liquid discharge head unit 210Y will be described as an example.

  In step S01, the transported object detection device irradiates light having a wavelength that matches the color, and acquires first image data. In this example, the first image data is image data captured by the optical sensor OS1 upstream of the yellow liquid ejection head unit 210Y. First, in step S01, the conveyed object detection device irradiates light from the light source LGY1. Then, in a state where light is irradiated from the light source LGY1, that is, in a state where yellow light is irradiated on the web 120, the optical sensor OS1 performs imaging and generates first image data. In the transport direction 10, the color of light projected by the light source LG upstream from the most upstream liquid discharge head unit 210 is not limited.

  In step S02, the image forming apparatus discharges liquid from the liquid discharge head unit. In this example, the image forming apparatus discharges yellow ink onto the web 120 from the yellow liquid discharge head unit 210Y.

  In step S03, the conveyed object detection device irradiates light having a wavelength that matches the color, and acquires second image data. In this example, the second image data is image data captured by the optical sensor OS2 downstream of the yellow liquid ejection head unit 210Y. First, in step S03, the conveyed object detection device irradiates light from the light source LGY2. Then, in a state where light is emitted from the light source LGY2, that is, in a state where yellow light is irradiated on the web 120, the optical sensor OS2 performs imaging and generates second image data.

  In step S04, the conveyed object detection device calculates a relative position, a position, a moving amount, a moving speed, or a combination thereof based on the first image data and the second image data. That is, in step S04, the transported object detection device can calculate the shift amount in the orthogonal direction, the shift amount in the transport direction, and the like by comparing the respective image data captured upstream and downstream of the yellow liquid ejection head unit 210Y. . In this manner, the transported object detection apparatus can calculate the movement amount and movement speed of the web 120 from the image data.

  For example, combinations of the first image data and the second image data acquired for each liquid ejection head unit are as follows.

  FIG. 23 is a diagram illustrating an example of the first image data and the second image data acquired by the apparatus for ejecting liquid according to an embodiment of the present invention. In the figure, the first image data, that is, image data generated upstream of the liquid ejection head unit is shown in the upper part. The lower part shows second image data, that is, image data generated downstream of the liquid ejection head unit.

  In the illustrated example, the first pair PR1 of the yellow light irradiation first image data IMG1Y and the yellow light irradiation second image data IMG2Y is used for the calculation for the yellow liquid discharge head unit 210Y. First, the yellow light irradiation first image data IMG1Y is before yellow ink is ejected. On the other hand, the yellow light irradiation second image data IMG2Y is after the yellow ink is ejected. Yellow ink easily reflects yellow light and easily absorbs light other than yellow light. Therefore, even when the first character CR1 and the like are formed with yellow ink by the yellow liquid discharge head unit 210Y, yellow light is easily reflected in the portion where the first character CR1 is described, and the first character CR1 is described. Less impact.

  In the illustrated example, the second pair PR2 of the magenta light irradiation first image data IMG1M and the magenta light irradiation second image data IMG2M is used for the calculation for the magenta liquid ejection head unit 210M. First, the magenta light irradiation first image data IMG1M is after the yellow ink is ejected and before the magenta ink is ejected. On the other hand, the magenta light irradiation second image data IMG2M is after the magenta ink is ejected. Magenta ink easily reflects magenta light and easily absorbs light other than magenta light. Therefore, even if the second character CR2 or the like is formed with magenta ink by the magenta liquid ejection head unit 210M, magenta light is easily reflected in the portion where the second character CR2 is described, and the second character CR2 is described. Less impact.

  In the illustrated example, the third pair PR3 of cyan light irradiation first image data IMG1C and cyan light irradiation second image data IMG2C is used for the calculation for the cyan liquid ejection head unit 210C. First, the cyan light irradiation first image data IMG1C is after the magenta ink is ejected and before the cyan ink is ejected. On the other hand, the cyan light irradiation second image data IMG2C is after the cyan ink is ejected. Cyan ink easily reflects cyan light and easily absorbs light other than cyan light. Therefore, even if the third character CR3 or the like is formed with cyan ink by the cyan liquid ejection head unit 210C, cyan light is easily reflected in the portion where the third character CR3 is described, and the third character CR3 is described. Less impact.

  In the illustrated example, the fourth pair PR4 of the infrared light irradiation first image data IMG1K and the infrared light irradiation second image data IMG2K is used for the calculation for the black liquid discharge head unit 210K. First, the infrared light irradiation first image data IMG1K is after cyan ink is ejected and before black ink is ejected. On the other hand, the infrared light irradiation second image data IMG2K is after the black ink is ejected. Black ink absorbs most wavelengths of light in the visible region. For this reason, even if the black liquid discharge head unit 210K forms characters or the like with black ink, if infrared light or the like reflected at the portion where the characters are described is used, the influence of the characters being described is small.

  As shown in the drawing, when a plurality of image data is generated by one sensor device, the number of sensors can be reduced. Further, by reducing the number of sensor devices, an effect such as a reduction in cost can be obtained.

<Functional configuration example>
FIG. 24 is a functional block diagram showing an example of a functional configuration of a device for ejecting liquid according to an embodiment of the present invention. As shown in the figure, the image forming apparatus 110 includes a plurality of detection units and at least one calculation unit 53F.

  In the example illustrated in FIG. 3, the detection units 52A, 52B, 52C, 52D, and 52E are arranged one by one at each arrangement position, and five detection units are arranged. And based on the detection result by a detection part, the calculation part 53F detects the position in the orthogonal | vertical direction of the web 120, a conveyance direction, or both directions.

  The detection unit detects the surface of the web 120 irradiated with light corresponding to the liquid discharged from the liquid discharge head unit by the light source shown in FIG. Specifically, the surface of the web 120 irradiated with light having a high relative intensity in the wavelength range corresponding to the wavelength range in which the relative reflectance of the liquid is high is detected.

  Note that the image forming apparatus 110 may further include a control unit 54F. As illustrated, the control unit 54F controls the timing at which the liquid is discharged onto the web 120, the position of the liquid discharge head unit in the orthogonal direction, and the like based on the calculation result by the calculation unit 53F.

  Similarly, for 210M, 210C, and 210K, the calculation unit 53F detects the position of the web 120 in the orthogonal direction, the conveyance direction, or both directions, based on the detection results detected using the upstream and downstream detection units. The control unit 54F controls the timing at which the liquid is discharged onto the web 120 or the position of the liquid discharge head unit in the orthogonal direction.

<First Modification>
For example, the sensor and the light source may have the following configurations.

  FIG. 25 is a schematic diagram illustrating a first modification of the overall configuration of the apparatus for ejecting liquid according to an embodiment of the present invention.

  In this 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. In the illustrated example, for each liquid discharge head unit, a roller (hereinafter referred to as a “first roller”) used to transport the web 120 to each discharge position is installed on the upstream side of each liquid discharge head unit. The Further, rollers (hereinafter referred to as “second rollers”) used to convey the web 120 downstream from the respective ejection positions are respectively installed on the downstream side of the respective liquid ejection head units. In this way, when the first roller and the second roller are installed, so-called “flapping” can be reduced at each discharge position. The first roller and the second roller are installed in the recording medium conveyance path, and are, for example, driven rollers. 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, a first yellow roller CR1Y is installed upstream of the yellow discharge position PY in the transport direction. On the other hand, the second yellow roller CR2Y is installed downstream of the yellow discharge position PY in the transport direction. Similarly, a first magenta roller CR1M and a second magenta roller CR2M are installed for the magenta liquid ejection head unit 210M. Further, a cyan first roller CR1C and a cyan second roller CR2C are respectively installed on the cyan liquid discharge head unit 210C. Further, a black first roller CR1K and a black second roller CR2K are respectively installed on the black liquid discharge head unit 210K.

  As shown in the drawing, the position where the sensor is installed is preferably a position close to each discharge position. If a sensor is installed at a position close to each discharge position, the distance between each discharge position and the sensor is shortened. When the distance between each ejection position and the sensor is shortened, errors in detection can be reduced. Therefore, the image forming apparatus can accurately detect the position and speed of the recording medium in the transport direction, the orthogonal direction, or both directions by the sensor.

  Specifically, the position close to each discharge position is between each first roller and each second roller. That is, in the illustrated example, it is desirable that the position where the first upstream sensor device SN11 and the first downstream sensor device SN12 for yellow are installed is the inter-yellow roller INTY1 as illustrated. Similarly, the position where the second upstream sensor device SN21 and the second downstream sensor device SN22 for magenta are installed is preferably the magenta roller INTM1 as illustrated. Furthermore, it is desirable that the position where the third upstream sensor device SN31 and the third downstream sensor device SN32 for cyan are installed is an inter-cyan roller INTC1, as shown in the figure. Furthermore, it is desirable that the position where the fourth upstream sensor device SN41 and the fourth downstream sensor device SN42 for black are installed is the inter-black roller INTK1 as illustrated.

  Thus, when a sensor is installed between each roller, the sensor can detect the position of the recording medium at a position close to each ejection position. In many cases, the conveyance speed is relatively stable between the rollers. Therefore, the image forming apparatus can accurately detect the position and speed of the recording medium in the transport direction and the orthogonal direction.

  In this configuration, the first image data and the second image data of the first pair PR1 are generated by the first upstream sensor device SN11 and the first downstream sensor device SN12. Further, the second upstream sensor device SN21 and the second downstream sensor device SN22 generate the first image data and the second image data of the second pair PR2. Furthermore, the first image data and the second image data of the third pair PR3 are generated by the third upstream sensor device SN31 and the third downstream sensor device SN32. Then, the fourth upstream sensor device SN41 and the fourth downstream sensor device SN42 generate the first image data and the second image data of the fourth pair PR4.

<Second Modification>
FIG. 26 is a schematic diagram illustrating a second modification of the overall configuration of the apparatus for ejecting liquid according to an embodiment of the present invention. Compared to FIG. 25, 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.

<Third Modification>
FIG. 27 is a schematic diagram illustrating a third modification of the overall configuration of the apparatus for ejecting liquid according to an embodiment of the present invention. In this example, the apparatus for ejecting liquid detects the position and the like between two points using the sensor device on the upstream side of the liquid ejection head unit whose movement or ejection timing is to be controlled and the nearest sensor device. Then, control for moving the liquid discharge head unit, changing the discharge timing, or both may be performed.

  Specifically, the first sensor device SN101 is installed on the upstream side of the yellow discharge position PY, for example. Next, the second sensor device SN102 is installed upstream of the yellow discharge position PY and between the yellow discharge position PY and the first yellow roller CR1Y (hereinafter referred to as “yellow upstream section INTY2”). It is desirable to be done. Similarly, the third sensor device SN103 is located upstream of the magenta discharge position PM and between the magenta discharge position PM and the first magenta roller CR1M (hereinafter referred to as “magenta upstream section INTM2”). It is desirable to be done. Further, the fourth sensor device SN104 is located upstream of the cyan discharge position PC and between the cyan discharge position PC and the first cyan roller CR1C (hereinafter referred to as “cyan upstream section INTC2”). Is desirable. Furthermore, the fifth sensor device SN105 is located upstream from the black discharge position PK and between the black discharge position PK and the first black roller CR1K (hereinafter referred to as “black upstream section INTK2”). It is desirable to be done.

  When sensor devices 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 image forming apparatus accurately determines the position in the orthogonal direction, the transport direction, or both directions. It can be detected well. Further, when the sensor device is installed at such a position, the sensor device is on the upstream side from each discharge position. For this reason, the image forming apparatus can first accurately detect the position and the like on the upstream side in the orthogonal direction, the transport direction, or both directions.

  Next, the image forming apparatus can calculate the ejection timing, the amount by which the liquid ejection head unit is moved, or both. That is, after the position or the like is detected on the upstream side, the image forming apparatus can perform the calculation of the discharge timing or the control of moving the liquid discharge head unit until the web 120 is conveyed to the discharge position. Therefore, the image forming apparatus can change the ejection position with high accuracy.

  Note that 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 of each ejection position, the image forming apparatus can reduce color misregistration and improve image quality. In addition, there are cases where the vicinity of each discharge position or the like is restricted to a position where the sensor is installed. Therefore, the position where the sensor is installed is preferably closer to each first roller than each discharge position.

  On the other hand, the position where the sensor is installed may be, for example, directly below each liquid discharge head unit. In the following description, an example in which the sensor is directly below each liquid discharge head unit will be described. As in this example, when the position where the sensor is installed is directly below, an accurate movement amount immediately below can be detected. Therefore, if the control operation or the like can be performed quickly, the position where the sensor is installed is preferably closer to the position immediately below each liquid ejection head unit. On the other hand, the position where the sensor is installed 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 where the sensor is installed is directly below each liquid discharge head unit or between each first roller and each second roller, and directly below each liquid discharge head unit. It may be a downstream position or the like.

  FIG. 28 is a diagram showing a modification of detection and control by the device for ejecting liquid according to the third modification of the present invention.

  In the illustrated example, the image forming apparatus has a combination of detection results (hereinafter referred to as “first result RES1”) by the first sensor device SN101 and the second sensor device SN102 installed upstream of the yellow liquid ejection head unit 210Y. Based on this, control for moving the yellow liquid discharge head unit 210Y or control for changing the discharge timing of the yellow liquid discharge head unit 210Y is performed.

  In the illustrated example, the image forming apparatus includes a combination of detection results (hereinafter referred to as “second result RES2”) by the second sensor device SN102 and the third sensor device SN103 installed upstream of the magenta liquid ejection head unit 210M. ) To move the magenta liquid discharge head unit 210M or to change the discharge timing of the magenta liquid discharge head unit 210M.

  Further, in the illustrated example, the image forming apparatus has a combination of detection results (hereinafter referred to as “third result RES3”) by the third sensor device SN103 and the fourth sensor device SN104 installed upstream of the cyan liquid ejection head unit 210C. ), Control for moving the cyan liquid discharge head unit 210C or control for changing the discharge timing of the cyan liquid discharge head unit 210C is performed.

  Similarly, in the illustrated example, the image forming apparatus has a combination of detection results (hereinafter referred to as “fourth result RES4”) by the fourth sensor device SN104 and the fifth sensor device SN105 installed upstream of the black liquid discharge head unit 210K. )), The control for moving the black liquid discharge head unit 210K or the control for changing the discharge timing of the black liquid discharge head unit 210K is performed.

  Based on the first result RES1, the second result RES2, the third result RES3, and the fourth result RES4, for example, the image forming apparatus processes as follows.

  FIG. 29 is a timing chart showing a modification of detection and control by the device for ejecting liquid according to the third modification of the present invention.

  For example, in the case of the first result RES1, the detection result by the first sensor device SN101 becomes the first sensor data S1, and the detection result by the second sensor device SN102 becomes the second sensor data S2. Similarly, for example, in the case of the second result RES2, the detection result by the second sensor device SN102 becomes the first sensor data S1, and the detection result by the third sensor device SN103 becomes the second sensor data S2. Further, for example, in the case of the third result RES3, the detection result by the third sensor device SN103 becomes the first sensor data S1, and the detection result by the fourth sensor device SN104 becomes the second sensor data S2. For example, in the case of the fourth result RES4, the detection result by the fourth sensor device SN104 becomes the first sensor data S1, and the detection result by the fifth sensor device SN105 becomes the second sensor data S2.

  As shown in the figure, the image forming apparatus calculates a variation amount and the like based on a plurality of sensor data. Specifically, based on the first sensor data S1 and the second sensor data S2, the image forming apparatus outputs a calculation result indicating the variation amount. First, when each sensor data is transmitted from the sensor device, the image forming apparatus calculates a variation amount or the like from a plurality of detection results indicated by each sensor data.

  The fluctuation amount is calculated for each liquid discharge head unit. Hereinafter, an example of calculating the fluctuation amount for the cyan liquid ejection head unit 210C will be described. In this example, the fluctuation amount is calculated based on the third result RES3, for example.

  Assume that the distance between the optical sensor OS103 mounted on the third sensor device SN103 and the optical sensor OS104 mounted on the fourth sensor device SN104, that is, the distance between the sensors is “L2”. Further, it is assumed that the moving speed detected based on the sensor data is “V”. Furthermore, it is assumed that the movement time that elapses while the conveyed object is conveyed from the position of the optical sensor OS103 to the position of the optical sensor OS4 is “T2”. In this case, the travel time is calculated as “T2 = L2 / V”.

  The sampling interval by the sensor is “A”. Furthermore, the number of samplings between sensors is “n”. In this case, the sampling count is calculated as “n = T2 / A”.

  The calculation result shown in the drawing, that is, the fluctuation amount is “ΔX”. For example, as shown in the figure, when the detection cycle is “0”, the fluctuation amount is calculated by using the first sensor data S1 before the movement time “T2” and the second sensor data S2 of the detection cycle “0”. Calculated by comparison. Specifically, the fluctuation amount is calculated as “ΔX = X2 (0) −X1 (n)”.

  Next, the image forming apparatus controls the actuator so as to compensate for the fluctuation amount “ΔX” and moves the cyan liquid discharge head unit 210C in the orthogonal direction. In this way, even if the position of the transported object fluctuates, the image forming apparatus can accurately form an image on the transported object. Further, as shown in the figure, when the fluctuation amount is calculated based on the sensor data between two points, that is, the detection results by the two detection units, the fluctuation amount can be calculated without integrating the position information of each sensor device. . Therefore, in this way, the accumulation of detection errors by each sensor device can be reduced.

  Further, the sensor data is not limited to the detection result detected by the sensor device installed one upstream from the liquid discharge head unit to be moved. In other words, the sensor device may be a sensor device installed on the upstream side of the liquid ejection head unit to be moved or controlled.

  The second sensor data S2 is preferably a detection result by a sensor device installed at a position closest to the liquid ejection head unit to be moved or controlled.

  Further, the fluctuation amount or the like may be calculated based on three or more detection results.

  As described above, the liquid ejection head unit is controlled to move based on the fluctuation amount calculated from the plurality of sensor data, and when the liquid is ejected to the web, the liquid is landed accurately in the orthogonal direction. be able to. Similarly, when the discharge timing of the liquid discharge head unit is controlled based on the amount of fluctuation in the transport direction and the liquid is discharged onto the web, the liquid can be landed with high accuracy in the transport direction.

  Note that the image forming apparatus 110 may further include a moving unit that moves each of the liquid discharge head units based on the detection result. In this way, the apparatus for ejecting liquid according to an embodiment of the present invention can accurately compensate for the deviation that occurs at the position where the liquid is landed in the orthogonal direction. In particular, when a device that discharges liquid performs image formation, the liquid discharge head unit can be moved while the image is being formed to accurately compensate for the deviation generated at the liquid landing position. Can improve the image quality of the formed image.

  The image forming apparatus may further include a measurement unit such as an encoder. Hereinafter, an example in which the measurement unit is realized by an encoder will be described. Specifically, the encoder is installed with respect to the rotation shaft of the roller 230, for example. In this way, the movement amount in the transport direction can be measured based on the rotation amount of the roller 230. When this measurement result is used together with the detection result by the sensor, the image forming apparatus can discharge the liquid onto the web 120 with higher accuracy.

<Summary>
An apparatus for ejecting a liquid according to an embodiment of the present invention provides, for each liquid ejection head unit, light having a high relative intensity in a wavelength range corresponding to a wavelength range in which the relative reflectance of the liquid is high. The amount of movement or the movement speed is detected by irradiating the light. As described above, when light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high relative reflectance of the liquid is irradiated onto a character or the like formed by a liquid such as ink, the amount of movement or the movement speed is detected. It is possible to reduce a pattern or the like in the image data to be used. On the other hand, when such a pattern enters the image data, the detection accuracy deteriorates.

  Therefore, as in an embodiment of the present invention, a light source in which a pattern is difficult to enter image data is used. In this way, when the light matched to the color is irradiated, the pattern formed by the liquid and the light are assimilated, so that the influence of the pattern is reduced. Therefore, the apparatus that discharges the liquid can detect the movement amount or the movement speed with high accuracy by the detection unit.

  Moreover, since the color of the liquid discharged for every liquid discharge head unit differs, the apparatus which discharges a liquid irradiates the light of a different wavelength for every liquid discharge head unit. For example, in a liquid ejection head unit that uses yellow liquid, a device that ejects liquid irradiates yellow light and generates image data before and after ejecting the liquid.

  In the present embodiment, the apparatus for ejecting liquid performs detection on the surface from which the liquid is ejected. However, for example, in the case of so-called show-through in which the liquid can be seen through from the back surface, the apparatus that discharges the liquid can also apply the present invention to irradiation on the back surface and detection on the back surface.

  In addition, when an image is formed on a recording medium by discharging a liquid, the apparatus for discharging a liquid according to an embodiment of the present invention reduces color misregistration when the position where the liquid is landed becomes accurate. The quality of the image to be displayed can be improved.

<Modified Example of Conveyed Object Detection Device>
For example, the transported object detection device may be the following device.

  FIG. 30 is a block diagram illustrating a modified example of the hardware configuration for realizing the transported object detection device according to the embodiment of the present invention. For example, the transported object detection device is realized by an optical sensor OS, a first light source 51AA, a second light source 51AB, a control circuit 52, a storage device 53, a controller 520, and the like as illustrated. Compared with the configuration shown in FIG. 11, the optical sensor OS and the like are different in the illustrated configuration. Hereinafter, different points will be mainly described.

  The web 120 which is an example of the detection target is irradiated with laser light or the like from the first light source 51AA and the second light source 51AB. The position where the first light source 51AA emits light is referred to as “AA position”, and similarly, the position where the second light source 51AB emits light is referred to as “AB position”.

  The first light source 51AA and the second light source 51AB include a light emitting element that emits laser light and a collimator lens that makes the laser light emitted from the light emitting element substantially parallel. Further, the first light source 51AA and the second light source 51AB are installed at a position where the laser light is irradiated from an oblique direction to the surface of the web 120.

  The optical sensor OS includes an area sensor 11, a first imaging lens 12AA at a position facing the “AA position”, and a second imaging lens 12AB at a position facing the “AB position”.

  The area sensor 11 is, for example, a sensor configured to form the image sensor 112 on the silicon substrate 111. It is assumed that there are an “AA area 11AA” and an “AB area 11AB” on the image sensor 112, each of which can acquire two-dimensional image data. The area sensor 11 is, for example, a CCD image sensor, a CMOS image sensor, a photodiode array, or the like. The area sensor 11 is accommodated in the housing 13. Further, the first imaging lens 12AA and the second imaging lens 12AB are respectively held by the first lens barrel 13AA and the second lens barrel 13AB.

  In this example, as illustrated, the optical axis of the first imaging lens 12AA coincides with the center of the “AA region 11AB”. Similarly, the optical axis of the second imaging lens 12AB coincides with the center of the “AB region 11AB”. Then, the first imaging lens 12AA and the second imaging lens 12AB image light on the “AA area 11AA” and the “AB area 11AB”, respectively, and generate two-dimensional image data.

  In this case, the controller 520 can calculate a positional deviation or the like between the “AA position” and the “AB position”. Furthermore, the controller 520 can detect the position or the like between the sensor devices arranged at different positions by acquiring and calculating the detection results at the sensor devices or the like arranged at different positions in the transport direction.

  Furthermore, the conveyed object detection apparatus can also be used as, for example, the sensor device SN2, the sensor device SN3, and the sensor device SN4 by using the first light source 51AA and the second light source 51AB as light sources of different colors. is there.

  In addition, the transported object detection device may have a configuration described below.

  FIG. 31 is a diagram showing a first modification of the optical sensor according to one embodiment of the present invention. Compared to the configuration shown in FIG. 30, the configuration of the optical sensor OS shown in the drawing is different in that the first imaging lens 12AA and the second imaging lens 12AB are integrated to form the lens 12C. On the other hand, the area sensor 11 and the like have the same configuration as that shown in FIG. 30, for example.

  In this example, it is desirable to use the aperture 121 or the like so that the images of the first imaging lens 12AA and the second imaging lens 12AB do not interfere and form an image. As described above, when the aperture 121 or the like is used, the areas where the respective images of the first imaging lens 12AA and the second imaging lens 12AB are formed can be limited. Therefore, interference between the respective image formations can be reduced, and the optical sensor OS can generate image data at the respective positions at “AA position” and “AB position” shown in FIG.

  FIG. 32 is a diagram showing a second modification example of the optical sensor according to the embodiment of the present invention. Compared with the configuration shown in FIG. 31, the configuration of the optical sensor OS shown in FIG. 32A is different in that the area sensor 11 is the second area sensor 11 ′. On the other hand, the configuration of the first imaging lens 12AA, the second imaging lens 12AB, and the like is the same as that of FIG. 31, for example.

  The second area sensor 11 ′ has, for example, the configuration shown in FIG. Specifically, as illustrated in FIG. 32B, a plurality of imaging elements b are formed on the wafer a. Next, image sensors as illustrated in FIG. 32B are cut out from the wafer a. The first image sensor 112AA and the second image sensor 112AB, which are a plurality of image sensors to be cut out, are formed on the silicon substrate 111, respectively. In contrast, the positions of the first imaging lens 12AA and the second imaging lens 12AB are determined in accordance with the interval between the first imaging element 112AA and the second imaging element 112AB.

  An image sensor is often manufactured for imaging. For this reason, the ratio between the X direction and the Y direction of the image sensor, that is, the aspect ratio, is often a ratio that matches the image format, such as square, “4: 3”, or “16: 9”. In the present embodiment, image data is captured at two or more points that are separated by a certain interval. Specifically, image data is captured for each point that is spaced apart in the X direction, which is one direction in two dimensions, that is, in the transport direction. On the other hand, the image sensor has an aspect ratio that matches the image format. Therefore, in the case of imaging at two points that are separated by a certain interval in the X direction, the imaging element in the Y direction may not be used. Further, when the pixel density is increased, an image sensor having a high pixel density is used in either the X direction or the Y direction, which may increase the cost.

  Therefore, with the configuration illustrated in FIG. 32, the first image sensor 112AA and the second image sensor 112AB that are spaced apart from each other can be formed on the silicon substrate 111. Therefore, the number of image sensors that do not use the image sensor in the Y direction can be reduced. Therefore, waste of the image sensor can be reduced. Further, since the first image sensor 112AA and the second image sensor 112AB are formed by a highly accurate semiconductor process, the interval between the first image sensor 112AA and the second image sensor 112AB can be accurately performed.

  FIG. 33 is a schematic diagram illustrating an example of a plurality of imaging lenses used in an optical sensor according to an embodiment of the present invention. A lens array as shown may be used to implement the detector.

  The illustrated lens array has a configuration in which two or more lenses are integrated. Specifically, the illustrated lens array includes a total of nine imaging lenses A1 to C3 in three rows and three columns, for example, in the vertical and horizontal directions. When such a lens array is used, image data indicating nine points can be captured. In this case, an area sensor having nine imaging areas is used.

  The apparatus for ejecting liquid according to the present invention may be realized by a system for ejecting liquid having one or more apparatuses. For example, the black liquid discharge head unit 210K and the cyan liquid discharge head unit 210C are apparatuses having the same casing, and the magenta liquid discharge head unit 210M and the yellow liquid discharge head unit 210Y are apparatuses having the same casing. You may implement | achieve by the system which discharges the liquid which has.

  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.

  Further, in the embodiment according to the present invention, the image forming apparatus, the information processing apparatus, or a combination thereof may be realized by a program for causing a computer to execute part or all of the method for causing a computer to eject liquid.

  The light source is not limited to one using laser light. For example, the light source may be an organic EL (Electro-Luminescence) other than the LED as described above. Depending on the light source, the pattern may not be a speckle pattern.

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

  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, using a laser emitted from a head unit. Specifically, the transport device first has laser heads arranged in a line in the orthogonal direction. 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.

  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 Image forming apparatus 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 520 Controller

Japanese Patent Laying-Open No. 2015-13476

Claims (14)

An apparatus for discharging liquid having a liquid discharge head unit for discharging liquid,
A light source for irradiating the transported object with light having a high relative intensity in a wavelength region having a high relative reflectance of the liquid;
Conveyed object detection that has an optical sensor that images the conveyed object irradiated with the light, and detects at least one of a movement amount or a movement speed of the conveyed object based on generated image data The apparatus which discharges a liquid provided with a part.   The apparatus for discharging a liquid according to claim 1, wherein the transported object detection unit obtains a detection result based on a pattern of the transported object. The pattern is generated by interference of light applied to the uneven shape formed on the transported object,
The apparatus for ejecting liquid according to claim 2, wherein the transported object detection unit obtains the detection result based on an image obtained by imaging the pattern.   The apparatus for discharging a liquid according to claim 2 or 3, wherein the transport object detection unit detects a position of the transport object based on a result of detecting the pattern at two or more different timings. The light source is a first light source installed upstream from the liquid ejection head unit and a second light source installed downstream from the liquid ejection head unit,
The transported object detection unit includes first and second optical sensors installed on the upstream side and the downstream side in the transport direction, respectively.
Of the plurality of image data, the first image data is generated upstream of the liquid ejection head unit,
5. The apparatus for ejecting liquid according to claim 1, wherein among the plurality of image data, second image data is generated downstream of the liquid ejection head unit. A first support member provided upstream of a position where the liquid discharged by the liquid discharge head unit lands on the transferred object, and used for transferring the transferred object;
A second support member provided downstream of the position where the liquid discharged by the liquid discharge head unit lands on the transferred object, and used for transferring the transferred object;
The transported object detection unit
The apparatus for discharging a liquid according to any one of claims 1 to 5, which is installed between the first support member and the second support member.   The apparatus for discharging liquid according to claim 6, wherein a position of the transported object detection unit is a position between the landing position and the first support member.   The apparatus for discharging a liquid according to claim 1, further comprising a moving unit that moves the liquid discharge head unit in a direction orthogonal to a direction in which the transfer object is transferred.   The apparatus which discharges the liquid of any one of Claim 1 thru | or 8 which discharges the said liquid based on the detection result by the said to-be-conveyed object detection part.   The apparatus for discharging a liquid according to claim 1, wherein the object to be transported is long.   The apparatus for ejecting liquid according to claim 1, wherein when the liquid is ejected, an image is formed on the transported object.   The apparatus for discharging a liquid according to claim 1, wherein the transported object detection unit performs detection on a surface on which the liquid is discharged. A method of discharging liquid performed by a liquid discharge device having a liquid discharge head unit for discharging liquid,
An irradiation procedure for irradiating a transported object with light having a high relative intensity in a wavelength region corresponding to a wavelength region in which the liquid has a high relative reflectance,
A transported object detection procedure in which a device that discharges liquid detects at least one of a moving amount or a moving speed of the transported object based on image data generated by imaging the portion irradiated with the light. And a method for discharging a liquid containing the same. A system for discharging liquid having one or more devices and having a liquid discharge head unit for discharging liquid,
A light source for irradiating the object with light having a high relative intensity in a wavelength region corresponding to a wavelength region having a high relative reflectance of the liquid;
Based on image data generated by imaging the location irradiated with the light, a transported object detecting unit that detects at least one of a moving amount or a moving speed of the transported object is ejected. system.

Images