Liquid ejection device, liquid ejection method, and program

Abstract

To provide a liquid discharge device that is excellent in accuracy of detecting discharge failure.SOLUTION: A liquid discharge device for imparting liquid to a surface to be imparted includes: a head for imparting the liquid discharged from a nozzle to the surface to be imparted; and an output part for outputting discharge failure information of the nozzle that is detected on the basis of a shape of the liquid imparted to the surface to be imparted.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection apparatus, a liquid ejection method, and a program. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a liquid ejection device that detects ejection abnormalities of a nozzle based on liquid ejected from a nozzle provided in a head and applied to a receiving surface.

[0003] As the above-mentioned liquid ejection device, one has been disclosed in which an image formed on a surface to which liquid is ejected from a nozzle is read by a reading means, and ejection abnormalities of the nozzle are detected based on the reading results (see, for example, Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] Liquid ejection devices are required to have excellent accuracy in detecting ejection abnormalities.

[0005] An object of the present invention is to provide a liquid ejection apparatus that has excellent detection accuracy for ejection abnormalities. [Means for solving the problem]

[0006] A liquid ejection device according to one aspect of the present invention is a liquid ejection device that applies a liquid to a receiving surface, the liquid ejection device including: a head that applies the liquid ejected from a nozzle to the receiving surface; and an output unit that outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface. a movement mechanism that moves the head and the liquid-receiving surface relatively along the surface of the liquid-receiving surface, and a movement control unit that controls the relative movement by the movement mechanism, wherein the movement control unit controls the height of the liquid with respect to the liquid-receiving surface by controlling the relative movement speed by the movement mechanism, and the smaller the amount of the liquid ejected from the head, the slower the relative movement speed do. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a liquid ejection device that has excellent detection accuracy for ejection abnormalities. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view illustrating an example of the overall configuration of a liquid ejection device according to an embodiment. [Figure 2] 1 is a front view illustrating an example of the overall configuration of a liquid ejection device according to an embodiment. [Figure 3] FIG. 2 is a diagram illustrating a hardware configuration of a control unit according to the embodiment. [Figure 4] 3A and 3B are diagrams illustrating an example of a configuration of a supply unit according to the embodiment. [Figure 5] FIG. 2 is a perspective view illustrating the configuration of a head according to an embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the head taken along a plane P1 in FIG. 5. [Figure 7] FIG. 2 is a diagram illustrating an example of the functional configuration of a control unit according to the first embodiment. [Figure 8] FIG. 4 is a flowchart illustrating the operation of the liquid ejection device according to the first embodiment. [Figure 9] 5A and 5B are diagrams illustrating an example of detecting an ejection abnormality in the liquid ejection device according to the first embodiment. [Figure 10] 9A and 9B are diagrams showing examples of cross-sectional shape detection results taken along line IX-IX in FIG. [Figure 11] FIG. 10 is a diagram showing the luminance distribution of the read image along the line IX-IX in FIG. 9. [Figure 12] FIG. 10 is a diagram illustrating the relationship between the relative head movement speed and the ink height. [Figure 13] FIG. 10 is a diagram showing another first example of ejection abnormality detection according to the first embodiment. [Figure 14] FIG. 10 is a diagram showing another second example of ejection abnormality detection according to the first embodiment. [Figure 15] FIG. 10 is a diagram illustrating an example of the functional configuration of a control unit of a liquid ejection device according to a second embodiment. [Figure 16] FIG. 10 is a diagram illustrating ink height according to the second embodiment. [Figure 17] 10A and 10B are diagrams illustrating an example of application of the liquid ejection device according to the embodiment to a painting robot. DETAILED DESCRIPTION OF THE INVENTION

[0009] A liquid ejection device according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the following embodiments are merely examples of liquid ejection devices that embody the technical concept of the present embodiment, and are not intended to be limiting. Furthermore, unless otherwise specified, the dimensions, materials, shapes, and relative positions of components described in the embodiments are merely illustrative examples and are not intended to limit the scope of the present invention. Note that the size, positional relationships, etc. of components shown in each drawing may be exaggerated for clarity. Furthermore, in the following description, the same names and symbols indicate components that are the same or of the same quality, and detailed descriptions will be omitted as appropriate.

[0010] In the figures shown below, directions may be indicated by the X-axis, Y-axis, and Z-axis, but the X-direction along the X-axis indicates the main scanning direction in which the carriage provided in the liquid ejection device according to the embodiment moves, the Y-direction along the Y-axis indicates the sub-scanning direction that intersects with the main scanning direction, and the Z-direction along the Z-axis indicates the direction that intersects with both the X-direction and the Y-direction.

[0011] The X direction in which the arrow points is referred to as the +X direction, and the opposite direction of the +X direction is referred to as the -X direction. The Y direction in which the arrow points is referred to as the +Y direction, and the opposite direction of the +Y direction is referred to as the -Y direction. The Z direction in which the arrow points is referred to as the +Z direction, and the opposite direction of the +Z direction is referred to as the -Z direction. In the embodiment, the liquid ejection device ejects liquid in the +Z direction, as an example. However, these do not limit the orientation of the liquid ejection device when in use, and the orientation of the liquid ejection device is arbitrary.

[0012] [Embodiment] <Example of Overall Configuration of Liquid Ejection Apparatus 1000> The configuration of a liquid ejection device 1000 according to an embodiment will be described with reference to Figures 1 and 2. Figures 1 and 2 are diagrams illustrating an example of the overall configuration of the liquid ejection device 1000, with Figure 1 being a side view and Figure 2 being a front view.

[0013] The liquid ejection device 1000 applies ink, which is an example of a liquid, to a receiving surface 100a of the target object 100. The applied ink is fixed to the receiving surface 100a after drying. Either a continuous ejection method or a droplet ejection method can be applied as the ejection method used by the liquid ejection device 1000.

[0014] The receiving surface 100a of the object 100 is not particularly limited, but examples thereof include impermeable surfaces such as the bodies of cars, trucks, and airplanes. Impermeability refers to the property that a liquid applied to a surface does not penetrate into the interior. The liquid ejection device 1000 can paint the body of a car, truck, or airplane by applying ink to the body. FIG. 1 illustrates a planar receiving surface 100a extending along both the X and Y directions.

[0015] However, the liquid receiving surface 100a is not limited to a non-permeable surface and may be a permeable surface. Furthermore, the liquid receiving surface 100a is not limited to a flat surface and may be a curved surface. The use of the liquid ejection device 1000 is not limited to painting, and may be used for forming (printing) an image with ink on a recording medium such as paper or film.

[0016] 1 and 2, the liquid ejection device 1000 includes a head 300, a movement mechanism 110, a sensor 120, and a control unit 500. The liquid ejection device 1000 is disposed so that the head 300 faces a liquid receiving surface 100a.

[0017] The head 300 has a plurality of nozzles arranged at predetermined intervals in the Y direction, and applies ink ejected from each of the plurality of nozzles to the application surface 100a. The head 300 is mounted on a carriage 1. However, the head 300 does not necessarily have to have a plurality of nozzles, and may be configured to have only one nozzle.

[0018] The movement mechanism 110 is a mechanism that moves the head 300 and the application-receiving surface 100a relatively along the surface of the application-receiving surface 100a. In this embodiment, the movement mechanism 110 moves the head 300 and the application-receiving surface 100a relatively in each of the X direction and the Y direction along the surface of the application-receiving surface 100a. The movement mechanism 110 includes an X-axis rail 101 and a Y-axis rail 102.

[0019] The Z-axis rail 103 holds the carriage 1 so that it can move in the Z direction. The X-axis rail 101 holds the Z-axis rail 103 so that the Z-axis rail 103 holding the carriage 1 can move in the X direction. The Y-axis rail 102 holds the X-axis rail 101 so that it can move in the Y direction.

[0020] The Z-direction drive unit 92 moves the carriage 1 in the Z direction along the Z-axis rail 103. The X-direction drive unit 72 moves the Z-axis rail 103 in the X direction along the X-axis rail 101. The Y-direction drive unit 82 moves the X-axis rail 101 in the Y direction along the Y-axis rail 102. Note that the movement of the carriage 1 and head 300 in the Z direction does not have to be parallel to the Z direction, and may be oblique movement as long as it includes at least a Z-direction component.

[0021] The sensor 120 outputs shape information of the ink that is ejected from the nozzles of the head 300 and applied to the ink-receiving surface 100a. The sensor 120 is provided on the carriage 1 alongside the head 300 in the X direction.

[0022] The shape of the ink is a three-dimensional shape with axes in the X direction, Y direction, and Z direction, for example. The ink shape information includes information indicating the shape of the ink or information related to the shape of the ink. In this embodiment, the ink shape information includes information on the height of the ink relative to the ink receiving surface 100a, i.e., information on the length of the ink surface relative to the ink receiving surface 100a along approximately the Z direction.

[0023] The sensor 120 is an image sensor that projects light having a striped pattern onto the ink applied to the ink-application surface 100a and outputs information about the shape of the ink obtained based on a captured image of the projected striped pattern. The sensor 120 outputs the information about the shape of the ink to the control unit 500.

[0024] The stripe pattern is a pattern in which lines of light extending in a predetermined stripe direction are arranged in a direction approximately perpendicular to the stripe extension direction. Such a stripe pattern is distorted by bending at least some of the lines of light depending on the shape of the ink onto which the stripe pattern is projected. The sensor 120 processes the captured image to obtain ink shape information from the distortion of the stripe pattern. Methods such as Fourier transform analysis and Moire interference analysis can be used for image processing.

[0025] However, the light projected by the sensor 120 is not limited to having a striped pattern, and may have various patterns such as a grid pattern or a dot array pattern as long as the pattern is a predetermined pattern.

[0026] The sensor 120 is not limited to an image sensor, but may be an optical sensor that irradiates light such as laser light onto the ink applied to the ink-receiving surface 100a and measures the shape of the ink based on the light reflected by the ink. Various methods, such as triangulation and knife-edge methods, can be applied to such optical sensors. However, using an image sensor as the sensor 120 is more preferable in terms of high-speed detection and ease of detection operation, since it can measure the shape of the ink based on a single captured image.

[0027] The sensor 120 does not necessarily have to be installed alongside the head 300 in the X direction on the carriage 1. Furthermore, the installation position of the sensor 120 is not limited to the carriage 1 on which the head 300 is mounted, but may be a carriage provided separately from the carriage 1, etc.

[0028] Furthermore, in this embodiment, the sensor 120 has a computing unit that performs image processing on the captured image, but the present invention is not limited to this. For example, the sensor 120 may output the captured image to the control unit 500 as ink shape information, and the control unit 500 may acquire the ink shape information through image processing. Alternatively, if the sensor 120 is an optical sensor, the sensor 120 may output an electrical signal based on the light intensity of light reflected by the ink to the control unit 500 as ink shape information, and the control unit 500 may acquire the ink shape information based on this electrical signal.

[0029] The control unit 500 controls the application operation of the liquid ejection device 1000 to the liquid receiving surface 100a. The control unit 500 is configured with a processor, an electric circuit, or the like mounted on an electric board. The control unit 500 is electrically connected, by wire or wirelessly, to at least each drive unit that drives the movement mechanism 110 and the head 300. However, the position of the electric board on which the control unit 500 is mounted is arbitrary, and the electric board may be disposed remotely from the head 300, etc.

[0030] The liquid ejection device 1000 ejects ink from the head 300 toward the liquid-receiving surface 100a while moving the carriage 1 in each of the X, Y, and Z directions, thereby applying ink to the liquid-receiving surface 100a.

[0031] More specifically, the liquid ejection device 1000 ejects ink from the head 300 to apply ink to the application receiving surface 100a while moving the head 300 and the application receiving surface 100a relatively in the X direction, which is the main scanning direction.

[0032] After completing one relative movement in the X direction, the liquid ejection device 1000 moves the head 300 and the liquid-receiving surface 100a relatively in the Y direction, which is the sub-scanning direction. After completing one relative movement in the Y direction, the liquid ejection device 1000 again moves the head 300 and the liquid-receiving surface 100a relatively in the X direction, ejecting ink from the head 300 to apply ink to the liquid-receiving surface 100a. The liquid ejection device 1000 repeats such relative movement in both the X direction and the Y direction to apply ink to the liquid-receiving surface 100a.

[0033] When the receiving surface 100a is a flat object extending along the X and Y directions, the liquid ejecting device 1000 does not move the head 300 and the receiving surface 100a relative to each other in the Z direction during the ink application operation. When the receiving surface 100a has a shape with different heights in the Z direction, the liquid ejecting device 1000 moves the head 300 and the receiving surface 100a relative to each other in the Z direction during the ink application operation, depending on the shape of the receiving surface 100a.

[0034] <Example of hardware configuration of control unit 500> 3 is a block diagram illustrating the hardware configuration of a control unit 500 included in the liquid ejection device 1000. The control unit 500 includes a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, and an I / F (Interface) 504. These are electrically connected to one another via a system bus. The control unit 500 is implemented by, for example, a computer.

[0035] The control unit 500 is also electrically connected to the head 300, the X-direction driving unit 72, the Y-direction driving unit 82, the Z-direction driving unit 92, the storage unit 511, the display unit 512, the operation panel 513, the sensor 120, and the like.

[0036] The CPU 501 uses the RAM 503 as a work area and executes programs stored in the ROM 502 to control the overall operation of the control unit 500 .

[0037] The ROM 502 is a non-volatile memory that stores programs for controlling the CPU 501 to perform recording operations and other fixed data.

[0038] The RAM 503 is a volatile memory that temporarily stores data such as a picture or character to be drawn on the surface 100a to which the image is to be applied, and data such as the shape of the body of the target object 100.

[0039] The I / F 504 is an interface that enables communication between the control unit 500 and an external device such as a host PC (Personal Computer).

[0040] The storage unit 511 is an external storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive) that stores preset setting values. The information stored in the storage unit 511 may be read by the CPU 501 and used when executing a program.

[0041] The display unit 512, under the control of the control unit 500, displays a screen for setting the conditions for applying ink by the liquid ejection device 1000, a screen for reporting an ejection abnormality in the nozzles of the head 300, and the like.

[0042] The operation panel 513 is an operation input device such as a touch panel, keyboard, or mouse that accepts operations of the liquid ejection device 1000. The operation panel 513 is used to input values ​​(coordinates) for specifying an area on the liquid receiving surface 100a where ink is to be ejected, the movement speed of the carriage 1, specifying image data and three-dimensional coordinate information (body data) used for applying ink to the liquid receiving surface 100a, and the distance between the head 300 and the liquid receiving surface 100a, etc.

[0043] The display unit 512 and the operation panel 513 may be configured to be operated on a single screen such as a touch panel.

[0044] The X-direction driving unit 72 drives the carriage 1 in the X direction based on instructions from the control unit 500. The Y-direction driving unit 82 drives the carriage 1 in the Y direction based on instructions from the control unit 500. The Z-direction driving unit 92 drives the carriage 1 in the Z direction based on instructions from the control unit 500.

[0045] The control unit 500 controls the movement of the carriage 1 carrying the head 300, the sensor 120, etc. in the X and Y directions by controlling the operation of the X-direction drive unit 72 and the Y-direction drive unit 82. The control unit 500 also controls the movement of the head 300 in the Z direction relative to the carriage 1 by controlling the operation of the Z-direction drive unit 92. The control unit 500 also controls the ejection of ink from the head 300.

[0046] <Configuration example of supply unit 200> 4 is a diagram illustrating an example of the configuration of the supply unit 200 in the liquid ejection device 1000. The supply unit 200 supplies ink to the head 300.

[0047] The heads 300 include a head 300Y that ejects yellow (Y) ink, a head 300M that ejects magenta (M) ink, a head 300C that ejects cyan (C) ink, and a head 300K that ejects black (K) ink. Note that head 300 is a general term used when there is no particular distinction between heads 300Y, 300M, 300C, and 300K.

[0048] The head 300 may further include a head that ejects other inks, such as a head 300Q that ejects overcoat ink and a head 300P that ejects primer ink or white ink. The supply unit 200 can supply ink of each color to the heads 300 of each color.

[0049] The supply unit 200 includes an ink tank 330 as a sealed container that contains ink 325 of each color to be ejected from each head 300. The ink tank 330 and the inlet (supply port) of the head 300 are connected via tubes 333 so that the ink can flow therethrough.

[0050] On the other hand, the ink tank 330 is connected to the compressor 230 via a pipe 331 including an air regulator 332, and the compressor 230 supplies pressurized air. As a result, pressurized ink 325 of each color is supplied to the inlet of each head 300, and the liquid ejection device 1000 ejects the ink 325 from the nozzle of each head 300.

[0051] <Configuration example of head 300> 5 and 6 are diagrams illustrating the configuration of the head 300. Fig. 5 is a perspective view, and Fig. 6 is a cross-sectional view of the head 300 taken along plane P1 in Fig. 5.

[0052] The head 300 has a plurality of ejection modules 310 arranged in one or more rows within the housing 10 .

[0053] The head 300 has a supply port 11 and a recovery port 12. The supply port 11 supplies pressurized ink from the outside to the ejection module 310, and the recovery port 12 discharges ink that has not been ejected to the outside. The housing 10 also has a connector 2.

[0054] The ejection module 310 has a nozzle plate 311 with nozzles 321 that eject ink, a flow path 322 that communicates with the nozzles 321 and supplies pressurized liquid, and a piezoelectric element 324 that drives a needle-shaped valve body that opens and closes the nozzles 321.

[0055] The nozzle plate 311 is joined to the housing 10. The flow path 322 is a flow path common to the multiple ejection modules 310 provided in the housing 10, and supplies pressurized ink from the supply port 11 and discharges ink from the recovery port 12. Note that while ink is being ejected onto the ink receiving surface 100a, it is not necessary to temporarily suspend the discharge of ink from the recovery port 12 so as not to reduce the efficiency of ink ejection from the nozzles 321.

[0056] [First embodiment] <Example of functional configuration of control unit 500> 7 is a block diagram illustrating the functional configuration of the control unit 500. The control unit 500 has an ink type acquisition unit 51, an ink amount determination unit 52, an ejection control unit 53, a speed determination unit 54, a movement control unit 55, an ejection abnormality detection unit 56, and an output unit 57.

[0057] The control unit 500 controls the operation of the liquid ejection device 1000 to apply ink to the liquid receiving surface 100a, and can also detect ejection abnormalities in the nozzles of the head 300 and output information about the nozzle ejection abnormalities.

[0058] Specifically, the control unit 500 determines the amount of ink m to be ejected from the head 300 and the relative movement speed v of the head 300 with respect to the ink-receiving surface 100a using the ink amount determination unit 52 and the speed determination unit 54, in accordance with type information U of the ink 325 acquired by the ink type acquisition unit 51. The control unit 500 controls the ejection of the ink 325 from the head 300 using the ejection control unit 53, and controls the movement of the head 300 with respect to the ink-receiving surface 100a using the movement control unit 55, in accordance with the determined ink amount m and relative movement speed v. The control unit 500 also detects an ejection abnormality in the nozzles of the head 300 using the ejection abnormality detection unit 56, based on the ink shape information output from the sensor 120, and outputs information about the nozzle ejection abnormality via the output unit 57.

[0059] The control unit 500 implements the functions of an ink type acquisition unit 51, an ink amount determination unit 52, an ejection control unit 53, a speed determination unit 54, a movement control unit 55, and an ejection abnormality detection unit 56 by having the CPU 501 load a program stored in the ROM 502 into the RAM 503 and execute it. The control unit 500 also implements the function of an output unit 57 by the I / F 504.

[0060] At least some of the functions of the control unit 500 may be performed by a component other than the control unit 500, such as the head 300 or the sensor 120. Furthermore, at least some of the functions of the control unit 500 may be distributed and realized by the control unit 500 and a component other than the control unit 500.

[0061] The ink type acquisition unit 51 acquires type information U of the ink 325 ejected from the head 300 by the liquid ejection device 1000. The ink type acquisition unit 51 can acquire the type information U of the ink 325 input by a user of the liquid ejection device 1000 (hereinafter simply referred to as the user) via, for example, the operation panel 513. The ink type acquisition unit 51 may also acquire the type information U of the ink 325 by reading it out from a memory unit 511 or the like that has been stored in advance. The ink type acquisition unit 51 outputs the ink type information U to the ink amount determination unit 52 and the speed determination unit 54.

[0062] The ink amount determination unit 52 determines the ink amount m (amount of liquid) to be ejected from the head 300 based on the type information U of the ink 325 input from the ink type acquisition unit 51, and by referencing ink information 520 stored in the storage unit 511. The ink information 520 includes information relating to the relationship between a predetermined ink type and the ink amount m. The ink amount determination unit 52 outputs information on the determined ink amount m to the ejection control unit 53.

[0063] The ejection control unit 53 controls the ejection of ink 325 by the head 300. In this embodiment, in particular, the ejection control unit 53 controls the amount of ink m ejected from the head 300, thereby controlling the height of the ink 325 applied to the ink-receiving surface 100a relative to the ink-receiving surface 100a.

[0064] In the case of a continuous ejection method, the ejection control unit 53 can increase the amount of ink m ejected from the head 300 by lengthening the time for which the head 300 ejects the ink 325, increasing the speed at which the ink 325 is ejected from the head 300, or increasing the opening area of ​​the nozzle.

[0065] Furthermore, in the case of a droplet ejection method, the ejection control unit 53 can increase the amount of ink m ejected from the head 300 by increasing the volume of an ink droplet formed from the ink 325 or by increasing the drive voltage of the head 300. The ejection control unit 53 can increase the volume of an ink droplet, for example, by combining multiple ink droplets.

[0066] The relationship information between the type of ink 325 and the ink amount m includes relationship information between the surface tension of the ink 325 associated with the type of ink 325 and the ink amount m, or relationship information between the viscosity of the ink 325 associated with the type of ink 325 and the ink amount m, etc.

[0067] The ink amount determination unit 52 determines the amount of ink m to be ejected from the head 300 so that the smaller the surface tension of the ink 325 is, the greater the amount of ink m to be ejected from the head 300. Alternatively, the ink amount determination unit 52 determines the amount of ink m to be ejected from the head 300 so that the lower the viscosity of the ink 325 is, the greater the amount of ink m to be ejected from the head 300. The ejection control unit 53 can cause the head 300 to eject the amount of ink m determined by the ink amount determination unit 52.

[0068] The speed determination unit 54 determines the relative movement speed v between the head 300 and the ink-receiving surface 100a, based on the type information U of the ink 325 input from the ink type acquisition unit 51, with reference to the ink information 520 stored in the storage unit 511. The ink information 520 includes information on the relationship between the predetermined type of ink 325 and the relative movement speed v. The speed determination unit 54 outputs information on the determined relative movement speed v to the movement control unit 55.

[0069] The movement control unit 55 controls the relative movement by the movement mechanism 110. In this embodiment, the movement control unit 55 controls the relative movement by the movement mechanism 110 by controlling the X-direction drive unit 72, the Y-direction drive unit 82, and the Z-direction drive unit 92. Furthermore, particularly in this embodiment, the movement control unit 55 controls the relative movement speed v by the movement mechanism 110, thereby being able to control the height of the ink 325 applied to the ink-receiving surface 100a relative to the ink-receiving surface 100a.

[0070] The speed determination unit 54 determines the relative movement speed v to be slower as the amount of ink m ejected from the head 300 is smaller. Furthermore, the speed determination unit 54 determines the relative movement speed v to be slower as the surface tension of the ink 325 is smaller. Furthermore, the speed determination unit 54 determines the relative movement speed v to be slower as the viscosity of the ink 325 is lower. The movement control unit 55 can move the head 300 relative to the application receiving surface 100a at the relative movement speed v determined by the speed determination unit 54.

[0071] The ejection abnormality detection unit 56 detects ejection abnormalities of the nozzles based on the shape of the ink 325 applied to the ink receiving surface 100a. In this embodiment, the ejection abnormality detection unit 56 detects ejection abnormality information Ne of the nozzles based on shape information of the ink 325 output from the sensor 120. The ejection abnormality detection unit 56 outputs the detected ejection abnormality information Ne of the nozzles via the output unit 57. In this embodiment, the nozzle ejection abnormality information Ne includes ejection abnormality nozzle information Nn that identifies the ejection abnormal nozzle among the multiple nozzles.

[0072] The ejection abnormality detection unit 56 can output the nozzle ejection abnormality information Ne to the display unit 512 via the output unit 57, for example, and display it on the display unit 512. Alternatively, the ejection abnormality detection unit 56 can output the nozzle ejection abnormality information Ne to the memory unit 511 via the output unit 57 and store it in the memory unit 511, or can transmit the nozzle ejection abnormality information Ne to an external device of the liquid ejection device 1000.

[0073] <Example of Operation of Liquid Discharge Apparatus 1000> Fig. 8 is a flowchart illustrating an example of the operation of the liquid ejection device 1000. Fig. 8 illustrates an example of an ejection abnormality detection operation by the liquid ejection device 1000. The liquid ejection device 1000 starts the operation of Fig. 8 when it receives an ejection abnormality detection instruction input by the user using, for example, the operation panel 513.

[0074] First, in step S81, the liquid ejection device 1000 acquires type information U of the ink 325 ejected from the head 300 by the liquid ejection device 1000 using the ink type acquisition unit 51. The ink type acquisition unit 51 outputs information indicating the type of ink 325 to the ink amount determination unit 52 and the speed determination unit 54.

[0075] Next, in step S82, the liquid ejection device 1000 determines the amount of ink m to be ejected from the head 300 by the ink amount determination unit 52, based on the type information U of the ink 325 input from the ink type acquisition unit 51, and by referring to the ink information 520 stored in the storage unit 511. The ink amount determination unit 52 outputs information on the determined ink amount m to the ejection control unit 53.

[0076] Next, in step S83, the liquid ejection device 1000 determines the relative movement speed v between the head 300 and the application receiving surface 100a by the speed determination unit 54, based on the type information U of the ink 325 input from the ink type acquisition unit 51, and by referring to the ink information 520 stored in the storage unit 511. The speed determination unit 54 outputs the determined relative movement speed information to the movement control unit 55.

[0077] The order of the operations in steps S82 and S83 may be reversed, or both may be performed in parallel.

[0078] Next, in step S84, the liquid ejection device 1000 applies ink 325 to the surface 100a by controlling the relative movement between the head 300 and the surface 100a by the movement mechanism 110 using the movement control unit 55, and also by controlling the ejection of ink 325 by the head 300 using the ejection control unit 53.

[0079] Subsequently, in step S85, the liquid ejecting apparatus 1000 acquires from the sensor 120 shape information of the ink 325 applied to the liquid receiving surface 100a.

[0080] Subsequently, in step S86, the liquid ejection device 1000 causes the ejection abnormality detection unit 56 to detect an ejection abnormality of the nozzle based on the shape of the ink 325 applied to the ink receiving surface 100a.

[0081] Subsequently, in step S87, the liquid ejection device 1000 outputs, via the output section 57, the ejection abnormality information Ne of the nozzle detected by the ejection abnormality detection section .

[0082] Next, in step S88, the liquid ejection device 1000 determines whether or not to end the ejection abnormality detection operation using the control unit 500. For example, the control unit 500 can determine whether or not to end the ejection abnormality detection operation based on an operation input by the user using the operation panel 513, or based on the determination result of whether or not the number of ejection abnormality detection operations has reached a preset number.

[0083] If it is determined in step S88 that the operation should be ended (step S88, Yes), the liquid ejection device 1000 ends the operation. On the other hand, if it is determined that the operation should not be ended (step S88, No), the liquid ejection device 1000 performs the operations from step S84 onwards again.

[0084] In this way, the liquid ejection device 1000 can detect ejection abnormalities in the nozzles of the head 300.

[0085] <Operation of the liquid ejection device 1000> (Example of detecting ejection abnormalities based on ink shape) 9 and 10 are diagrams showing an example of the detection results of an ejection abnormality by the liquid ejection device 1000. Fig. 10 is a diagram showing an example of the detection results of the cross-sectional shape along line IX-IX in Fig. 9. Fig. 9 shows an example of nozzles 321a to 321e, which are multiple nozzles included in the head 300, and linear patterns L1 to L5 made of ink 325 ejected from the head 300 and applied to the application surface 100a.

[0086] In FIG. 9, nozzles 321a, 321b, 321d, and 321e indicated by white circles are nozzles from which ink 325 was normally ejected, and nozzle 321c indicated by a black circle is a non-ejecting nozzle from which ink 325 was not ejected due to an ejection abnormality.

[0087] The head 300 ejects ink 325 from each nozzle while being moved in the X direction by the movement mechanism 110, thereby forming a linear pattern extending along the X direction on the application receiving surface 100a in correspondence with each nozzle.

[0088] The X direction is an example of a pattern extension direction. The linear pattern extending along the X direction is an example of a predetermined pattern, and is also an example of a plurality of linear patterns formed on the ink-application surface 100a by the ink 325 ejected from each of the plurality of nozzles 321a to 321e and extending in the X direction.

[0089] In the example of FIG. 9, the color of the ink receiving surface 100a and the color of the ink 325 are of the same color family. Colors of the same color family can also be said to be colors that are similar in hue. Examples of colors of the same color family include when the color of the ink 325 is black and the color of the ink receiving surface 100a is a gray that is close to black. Other examples of colors of the same color family include when the color of the ink 325 is white and the color of the ink receiving surface 100a is a cream color that is close to white, and when the color of the ink 325 is red and the color of the ink receiving surface is burgundy.

[0090] 9, a linear pattern L1 is formed by the ink 325 ejected from nozzle 321a, and a linear pattern L2 is formed by the ink 325 ejected from nozzle 321b. Furthermore, a linear pattern L4 is formed by the ink 325 ejected from nozzle 321d, and a linear pattern L5 is formed by the ink 325 ejected from nozzle 321e. Because nozzle 321c is a non-ejecting nozzle, no linear pattern is formed at a position on the ink-receiving surface 100a corresponding to nozzle 321c.

[0091] The sensor 120 measures the shape of the ink-receiving surface 100a and the shape of the ink 325 applied to the ink-receiving surface 100a. The cross-sectional shape of the shape measured by the sensor 120 along line IX-IX in Fig. 9 is shown in Fig. 10. In Fig. 10, the horizontal axis represents the position along the Y direction, and the vertical axis represents the height along the Z direction.

[0092] Shape S1 corresponds to the cross-sectional shape of linear pattern L1, shape S2 corresponds to the cross-sectional shape of linear pattern L2, shape S4 corresponds to the cross-sectional shape of linear pattern L4, and shape S5 corresponds to the cross-sectional shape of linear pattern L5.

[0093] The height h of shapes S1, S2, S4, and S5 is higher than the ink-receiving surface 100a by the amount of ink 325 applied. On the other hand, since no linear pattern corresponding to nozzle 321c is formed, the height of shape S3 corresponding to nozzle 321c is approximately the same height as the ink-receiving surface 100a. Note that "approximately the same height" here means that it includes a difference due to noise from sensor 120.

[0094] Based on the shape of the ink 325 applied to the receiving surface 100a, the liquid ejection device 1000 can detect the nozzle as an abnormal ejection nozzle, for example, if a shape higher than a predetermined height threshold is not obtained in an area corresponding to the position of the nozzle of the head 300 on the receiving surface 100a.

[0095] 9 and 10, a shape higher than the predetermined height threshold cannot be obtained in the region corresponding to nozzle 321c. Therefore, the liquid ejection apparatus 1000 can output abnormal ejection information Ne indicating that nozzle 321c is experiencing an ejection abnormality. The liquid ejection apparatus 1000 can also output abnormal ejection nozzle information Nn, which identifies nozzle 321c as the abnormal ejection nozzle among the multiple nozzles.

[0096] In other words, in the nozzle ejection abnormality detection method according to the embodiment, the head 300 forms a linear pattern as a predetermined pattern on the receiving surface 100a using ink 325 ejected from each of the plurality of nozzles 321a to 321e. The output unit 57 outputs the ejection abnormality nozzle information Nn identified based on a second position on the receiving surface 100a where the height of the ink 325 constituting the linear pattern formed on the receiving surface 100a is lower than the height at the first position on the receiving surface 100a. The positions in the Y direction of the shapes S1, S2, S4, and S5 in FIG. 10 correspond to the first positions, and the position of the shape S3 corresponds to the second position.

[0097] Here, as a method for detecting nozzle ejection abnormalities in the comparative example, for example, a method is considered in which a linear pattern formed on the receiving surface 100a is read using a camera or scanner, and nozzle ejection abnormalities are detected based on this read image.

[0098] 9, when the color of the ink-receiving surface 100a and the color of the ink 325 are similar, the contrast of the color of the ink-receiving surface 100a with the color of the applied ink 325 is low. For this reason, with the method according to the comparative example, it may be impossible to identify the linear pattern in the read image and therefore impossible to detect the ejection abnormality.

[0099] 11 is a diagram showing the cross-sectional luminance distribution of the linear pattern in the captured image of the linear pattern according to the comparative example, which shows the cross-sectional luminance distribution of the read image along line IX-IX in FIG.

[0100] In Fig. 11, the horizontal axis represents the position along the Y direction, and the vertical axis represents the pixel luminance value (in units of gradation) in the read image. Note that in the example of Fig. 9, the color of the ink 325 is darker than the color of the ink-receiving surface 100a, so the pixel luminance value of the linear pattern is lower than the pixel luminance value of the ink-receiving surface 100a, but for convenience of explanation, the light and dark are reversed in Fig. 11, and the pixel luminance value 111 of the linear pattern is displayed as being higher than the pixel luminance value 112 of the ink-receiving surface 100a.

[0101] 11, there is a small difference between a pixel luminance value 111 in an area where a linear pattern is formed and a pixel luminance value 112 in an area where a linear pattern is not formed (an area on the application surface 100a). Therefore, the method according to the comparative example cannot identify an area where a linear pattern is not formed, making it difficult to detect an ejection abnormality in a nozzle.

[0102] The liquid ejection device 1000 according to the embodiment detects nozzle ejection abnormalities based on the shape of the ink 325 applied to the liquid receiving surface 100a, and can therefore detect nozzle ejection abnormalities without being affected by the contrast between the color of the liquid receiving surface 100a and the color of the ink 325. Because the liquid ejection device 1000 is not affected by color contrast, it can detect nozzle ejection abnormalities not only when the color of the liquid receiving surface 100a and the color of the ink 325 are similar colors, but also when the two are the same color.

[0103] In this embodiment, a method has been exemplified in which ink 325 is ejected from each of the plurality of nozzles 321a to 321e to form a linear pattern, and a nozzle that fails to form a linear pattern is detected as an ejection abnormality nozzle among the plurality of nozzles, but the method of detecting an ejection abnormality of a nozzle is not limited to this. For example, if the head 300 has only one nozzle, the liquid ejection device 1000 may eject ink 325 from one nozzle and detect an ejection abnormality of this nozzle based on whether a pattern of the ejected ink 325 is formed on the receiving surface 100a.

[0104] The predetermined pattern is not limited to a linear pattern, and may be a predetermined pattern such as a dot pattern or a filled pattern. The linear pattern is not limited to one that extends in the X direction, and may be one that extends in the Y direction, or one that extends in a direction intersecting the X direction or the Y direction within the application surface 100a.

[0105] (Example of controlling relative movement speed v) Next, the effect of moving the head 300 relative to the application receiving surface 100a at the relative movement speed v determined by the speed determining unit 54 will be described.

[0106] In this embodiment, nozzle ejection abnormalities are detected based on the shape of the ink 325 applied to the receiving surface 100a, in particular the height h of the ink 325. However, depending on the amount of ink m ejected from the nozzle, the viscosity or surface tension of the ink 325, and the like, the height h of the ink 325 relative to the receiving surface 100a may not be sufficient. If the height h of the ink 325 is not sufficient, the sensor 120 of the liquid ejection device 1000 may not be able to detect the linear pattern formed on the receiving surface 100a by the ink 325 ejected from normal nozzles, and thus the nozzle ejection abnormality may not be detected accurately.

[0107] In this embodiment, the movement control unit 55 controls the height of the ink 325 relative to the ink-receiving surface 100a by controlling the relative movement speed v by the movement mechanism 110. This ensures the height h of the ink 325 relative to the ink-receiving surface 100a in order to accurately detect ejection abnormalities in the nozzles.

[0108] Fig. 12 is a diagram illustrating an example of the relationship between the relative movement speed v of the head 300 and the ink height. Fig. 12 shows the height of the ink 325 applied to the receiving surface 100a when three droplets of ink 325 are ejected while the head 300 is moved in the movement direction 170 at three relative movement speeds v1, v2, and v3. The relationship between the relative movement speeds v1, v2, and v3 is v1>v2>v3.

[0109] When the head 300 is moved at a relative movement speed v1, the three ink droplets 325a, 325b, and 325c do not pile up, and each droplet has the same height h1.

[0110] When the head 300 is moved at relative movement speed v2, relative movement speed v2 is slower than relative movement speed v1, so the three ink droplets partially overlap, increasing the ink height by the amount of overlap. Ink 325d represents the first droplet of ink. The height of ink 325d is h1. Ink 325e represents the ink obtained as a result of a second droplet of ink overlapping ink 325d. Because the two droplets of ink overlap, the height of ink 325e is h2, which is higher than h1. Ink 325f represents the ink obtained as a result of a third droplet of ink further overlapping ink 325e. Because the three droplets of ink overlap, the height of ink 325f is h3, which is even higher than h2.

[0111] When the head 300 is moved at relative movement velocity v3, which is slower than relative movement velocity v2, a larger portion of the three ink droplets overlap compared to when the relative movement velocity v2 is used, resulting in a correspondingly higher ink height. Ink 325g represents the first droplet of ink. The height of ink 325g is h1. Ink 325h represents the ink obtained when a second droplet of ink is overlapped on top of ink 325g. Because the two droplets of ink overlap, the height of ink 325h is h4, which is higher than h1. Ink 325i represents the ink obtained when a third droplet of ink is further overlapped on top of ink 325h. Because the three droplets of ink overlap, the height of ink 325i is h5, which is even higher than h4.

[0112] As described above, the liquid ejecting device 1000 can increase the height of the ink 325 applied to the liquid receiving surface 100a as the relative movement speed v is decreased.

[0113] The smaller the amount m of ink ejected from the head 300, the lower the height h of the ink 325, so it is preferable for the movement control unit 55 to slow down the relative movement speed v. Furthermore, the smaller the surface tension of the ink 325, the lower the height h of the ink 325 as the ink 325 wets and spreads on the receiving surface 100a, so it is preferable for the movement control unit 55 to slow down the relative movement speed v. Furthermore, the lower the viscosity of the ink 325, the lower the height h of the ink 325 as the ink 325 spreads on the receiving surface 100a, so it is preferable for the movement control unit 55 to slow down the relative movement speed v. As a result, the liquid ejection device 1000 can ensure the height h of the ink 325 relative to the receiving surface 100a in order to accurately detect ejection abnormalities in the nozzles.

[0114] (Example of detecting ejection abnormalities other than non-ejection) In the above example, an example of detecting non-ejection among ejection abnormalities has been described, but ejection abnormalities that can be detected by the liquid ejection device 1000 are not limited to non-ejection. For example, in addition to non-ejection, the liquid ejection device 1000 can also detect ink amount abnormalities, in which the amount of ink m ejected from the nozzle deviates from a predetermined amount, and ink direction abnormalities, in which the direction of ink ejected from the nozzle deviates from a predetermined direction.

[0115] Fig. 13 is a diagram showing another first example of ejection abnormality detection, showing the cross-sectional shape of ink 325 when detecting an ink volume abnormality. Fig. 14 is a diagram showing another second example of ejection abnormality detection, showing the cross-sectional shape of ink 325 when detecting an ink velocity abnormality. Figs. 13 and 14 both show the cross-sectional shape at a position corresponding to line IX-IX in Fig. 9.

[0116] 13, shapes S6 to S10 represent the shapes of the ink 325 ejected from the five nozzles and applied to the ink receiving surface 100a. The heights of shapes S6, S7, S9, and S10 are substantially equal, i.e., height h7. In contrast, the height h8 of shape S8 is shorter than height h7.

[0117] The greater the ink amount m, the higher the height of the ink 325 deposited on the recipient surface 100a, and conversely, the smaller the ink amount m, the lower the height. Therefore, the liquid ejection device 1000 can detect, from the heights based on shapes S6 to S10, that the ink amount m ejected from the nozzle corresponding to shape S8 is less than the ink amount m (predetermined amount) ejected from the other nozzles, and can detect an abnormality in the ink amount of the nozzle corresponding to shape S8.

[0118] 14, shapes S11 to S15 represent the shapes of the ink 325 ejected from the five nozzles and applied to the ink receiving surface 100a. The distance between shape S11 and shape S12, and the distance between shape S14 and shape S15 are approximately equal, and are represented as distance d12. In contrast, the distance d13 between shape S12 and shape S13 is wider than distance d12.

[0119] The head 300 ejects ink 325 from the nozzles in a predetermined ejection direction. The predetermined ejection direction is, for example, a direction approximately perpendicular to the direction in which the multiple nozzles are arranged. If the direction of the ink 325 ejected from the nozzles deviates from the predetermined ejection direction, the ink application position on the ink application surface 100a will deviate accordingly, and the spacing between adjacent ink shapes will deviate from the predetermined spacing.

[0120] Therefore, based on shapes S11 to S15, the liquid ejection device 1000 can detect from the spacing between adjacent ink shapes that the ejection direction of ink 325 from the nozzle corresponding to shape S13 is deviated from the direction of ink 325 ejected from other nozzles (predetermined ejection direction), and can detect an abnormality in the ink direction of the nozzle corresponding to shape S13.

[0121] In addition to the above, the liquid ejection device 1000 can also detect, as an ejection abnormality, an abnormality in the liquid velocity, in which the velocity of the ink 325 ejected from the nozzles deviates from a predetermined velocity.

[0122] The liquid ejection device 1000 applies ink 325 to the liquid-receiving surface 100a by ejecting ink 325 from the head 300 while moving the head 300 and the liquid-receiving surface 100a relative to each other. Therefore, if the speed of the ink 325 ejected from the head 300 deviates from a predetermined speed, the timing at which the ink 325 is applied to the liquid-receiving surface 100a deviates from the predetermined timing. As a result, the application position of the ejected ink 325 on the liquid-receiving surface 100a deviates from the predetermined position along the direction of relative movement between the head 300 and the liquid-receiving surface 100a (the X direction in FIG. 9).

[0123] Based on the shape of the ink applied to the receiving surface 100a, the liquid ejection device 1000 can detect, from the ink application position along the relative movement direction, whether the speed of the ink 325 ejected from the abnormal ejection nozzle deviates from the ink speed (predetermined speed) ejected from other nozzles, and can detect abnormal ink speed in the nozzle.

[0124] <Effects of the liquid ejection device 1000> The following describes the effects of the liquid ejection device 1000. Conventionally, a technique has been known in which, based on the difference in color between the surface to which ink is applied and the ink color, the ink applied to the surface to which ink is applied is read using a scanner or the like, and the read image is subjected to a binarization process, and then the processed image is compared with the read image during normal ejection to detect ejection abnormalities.

[0125] However, with conventional technology, in cases where the color of the surface to which ink is applied and the color of the ink are the same color or similar colors, color contrast cannot be obtained, and binarization processing cannot be performed appropriately, making it impossible to detect ejection abnormalities.

[0126] In this embodiment, the liquid ejection device 1000 has a head 300 that applies ink 325 (liquid) ejected from a nozzle to the receiving surface 100a, and an output unit 57 that outputs nozzle ejection abnormality information Ne detected based on the shape of the ink 325 applied to the receiving surface 100a.

[0127] For example, the liquid ejecting device 1000 has a sensor 120 that outputs shape information of the ink 325 applied to the receiving surface 100a, and the output unit 57 outputs ejection abnormality information Ne of the nozzle detected based on the shape information of the ink 325 output from the sensor 120. The shape information of the ink 325 also includes height information of the ink 325 relative to the receiving surface 100a.

[0128] The liquid ejection device 1000 detects nozzle ejection abnormalities based on the shape of the ink 325 applied to the liquid receiving surface 100a, and is therefore not affected by the contrast between the color of the liquid receiving surface 100a and the color of the ink 325. This allows the liquid ejection device 1000 to detect nozzle ejection abnormalities with high accuracy even when the color of the liquid receiving surface 100a and the color of the ink 325 are the same color or similar colors. As a result, this embodiment can provide a liquid ejection device 1000 with excellent ejection abnormality detection accuracy.

[0129] For example, if the contrast Ct between the brightness Ct1 of the color of the ink receiving surface 100a and the brightness Ct2 of the color of the ink 325 satisfies the following formula (1), it becomes difficult to detect abnormal ejection of the nozzles using conventional methods. Ct = Ct1 / Ct2 ≤ 4 (1) The liquid ejection device 1000 has a particularly excellent effect when the contrast Ct is expressed by the formula (1).

[0130] However, application of this embodiment is not limited to cases where the color of the ink-receiving surface 100a and the color of the ink 325 are the same color or similar colors. The embodiment can also be applied to cases where the color of the ink-receiving surface 100a and the color of the ink 325 are different colors and have high contrast. The liquid ejection device 1000 can detect nozzle ejection abnormalities without using a scanner, camera, or the like, and therefore can ensure high accuracy in detecting nozzle ejection abnormalities without being affected by reading errors due to uneven lighting during reading, etc. Furthermore, because complex image processing for image noise removal, etc. is not required, the liquid ejection device 1000 can ensure high accuracy in detecting nozzle ejection abnormalities through simple processing.

[0131] In addition, in this embodiment, the liquid ejection device 1000 is exemplified as having a configuration including the head 300, the moving mechanism 110, the sensor 120, and the control unit 500, but components other than the head 300 and the output unit 57 included in the control unit 500 are not essential. The liquid ejection device 1000 can obtain the above-mentioned effects by having at least the head 300 and the output unit 57.

[0132] In this embodiment, it is also preferable that the ink-receiving surface 100a is non-permeable. With a non-permeable ink-receiving surface 100a, the ink 325 applied to the ink-receiving surface 100a does not penetrate into the ink-receiving surface 100a or the target object 100. This allows the liquid ejection device 1000 to detect the shape of the ink 325 on the ink-receiving surface 100a with high accuracy, ensuring high accuracy in detecting nozzle ejection abnormalities.

[0133] Furthermore, in this embodiment, nozzle ejection abnormalities include at least one of the following: non-ejection, in which ink 325 is not ejected from the nozzle; ink volume abnormality (liquid volume abnormality), in which the amount of ink 325 ejected from the nozzle deviates from a predetermined volume; ink direction abnormality (liquid direction abnormality), in which the direction of ink 325 ejected from the nozzle deviates from a predetermined ejection direction; and ink speed abnormality (liquid speed abnormality), in which the speed of ink 325 ejected from the nozzle deviates from a predetermined speed. In this embodiment, these ejection abnormalities can be detected based on the shape of ink 325 applied to the ink-receiving surface 100a, and therefore it is possible to provide a liquid ejection device 1000 that is highly versatile in dealing with nozzle ejection abnormalities.

[0134] In this embodiment, the head 300 has multiple nozzles, and the abnormal nozzle ejection information Ne includes abnormal nozzle ejection information Nn from the multiple nozzles. For example, the head 300 forms linear patterns L1 to L5 (predetermined patterns) on the liquid-receiving surface 100a using ink 325 ejected from each of the multiple nozzles. The output unit 57 outputs the abnormal nozzle ejection information Nn identified based on the position (second position) of the shape S3 on the liquid-receiving surface 100a where the height of the ink 325 constituting the linear patterns L1 to L5 formed on the liquid-receiving surface 100a is lower than the height h at each of the positions (first positions) of the shapes S1, S2, S4, and S5 on the liquid-receiving surface 100a. This allows the liquid-receiving device 1000 to detect the abnormal nozzle ejection by comparing the ink 325 ejected from normal nozzles other than the abnormal nozzle and applied to the liquid-receiving surface 100a with the ink 325 applied from the normal nozzles other than the abnormal nozzle, simplifying the detection process. Furthermore, the liquid ejection device 1000 can detect ejection abnormalities in each of the multiple nozzles in parallel, thereby improving the efficiency of the detection operation.

[0135] Furthermore, in this embodiment, linear patterns L1 to L5 are formed on the receiving surface 100a by ink 325 ejected from each of the plurality of nozzles 321a to 321e, and include a plurality of linear patterns extending in the X direction (pattern extension direction). This pattern extension direction is preferably the direction in which the head 300 moves relative to the receiving surface 100a while ejecting the ink 325. Because linear patterns make it easy to recognize an ejection abnormality when it occurs, the liquid ejecting device 1000 can easily detect the nozzle ejection abnormality by detecting the nozzle ejection abnormality based on the shape of the ink 325 in the plurality of linear patterns.

[0136] Furthermore, this embodiment includes a movement mechanism 110 that moves the head 300 and the ink-receiving surface 100a relatively along the surface of the ink-receiving surface 100a, and a movement control unit 55 that controls the relative movement by the movement mechanism 110. The movement control unit 55 controls the relative movement speed v by the movement mechanism 110, thereby controlling the height h of the ink 325 with respect to the ink-receiving surface 100a.

[0137] For example, the movement control unit 55 slows the relative movement speed v as the amount of ink 325 ejected from the head 300 decreases. Also, the movement control unit 55 slows the relative movement speed v as the surface tension of the ink 325 ejected from the head 300 decreases. Alternatively, the movement control unit 55 slows the relative movement speed v as the viscosity of the ink 325 ejected from the head 300 decreases.

[0138] The slower the relative movement speed v, the higher the ink 325 deposited on the receiving surface 100a will pile up relative to the receiving surface 100a. For this reason, when the ink 325 wets and spreads on the receiving surface 100a and a sufficient height h for detecting an ejection abnormality cannot be obtained, the liquid ejection device 1000 controls the relative movement speed v to be slower, thereby ensuring a sufficient height h of the ink 325 for detecting an ejection abnormality and ensuring high accuracy in detecting nozzle ejection abnormalities.

[0139] Furthermore, this embodiment has a discharge control unit 53 that controls the amount of ink 325 discharged from the head 300, thereby controlling the height of the ink 325 relative to the ink-receiving surface 100a.

[0140] For example, the lower the surface tension of the ink 325, the greater the amount of ink 325 ejected from the head 300 by the ejection control unit 53. Also, the lower the viscosity of the ink 325, the greater the amount of ink 325 ejected from the head 300 by the ejection control unit 53.

[0141] The greater the amount of ink 325 ejected from the head 300, the higher the ink 325 applied to the receiving surface 100a will be relative to the receiving surface 100a. For this reason, in cases where the ink 325 tends to wet and spread on the receiving surface 100a and a height h sufficient for detecting an ejection abnormality cannot be obtained, for example, the liquid ejection device 1000 controls the amount of ink 325 ejected from the head 300 to be increased, thereby ensuring a height h of the ink 325 sufficient for detecting an ejection abnormality and ensuring high accuracy in detecting nozzle ejection abnormalities.

[0142] [Second embodiment] Next, a liquid ejection device 1000a according to a second embodiment will be described. Note that the same components as those in the embodiments already described are given the same reference numerals, and redundant description will be omitted where appropriate.

[0143] In this embodiment, the head 300 ejects ink 325 multiple times so that the ink 325 is stacked vertically on the receiving surface 100a, and the output unit 57 outputs nozzle ejection abnormality information Ne detected based on the shape of the ink 325 stacked on the receiving surface 100a.

[0144] 15 is a block diagram illustrating the functional configuration of a control unit 500a included in a liquid ejection device 1000a according to this embodiment. The control unit 500a includes an ejection control unit 53a and a movement control unit 55a.

[0145] The ejection control unit 53a causes the head 300 to eject the ink 325 multiple times so that the ink 325 is piled up in the height direction on the application receiving surface 100a. The movement control unit 55a controls the relative movement of the head 300 and the application receiving surface 100a by the movement mechanism 110 so that the ink 325 ejected multiple times by the head 300 is piled up in the height direction.

[0146] The output unit 57 outputs the nozzle abnormality ejection information Ne detected based on the shape of the ink 325 piled up in the height direction on the ink receiving surface 100a under the control of the ejection control unit 53a.

[0147] Fig. 16 is a diagram illustrating an example of the height of ink 325 applied to the liquid receiving surface 100a by the liquid ejection device 1000a. Fig. 16 shows how ink 325 ejected three times from the head 300 is piled up on the liquid receiving surface 100a.

[0148] 16, in 1st representing the first ejection, ink 325k is applied to the ink-receiving surface 100a. The height of the ink 325 relative to the ink-receiving surface 100a is height h11.

[0149] In the second ejection, ink 325k is applied onto ink 325j that has been applied to the receiving surface 100a. As a result of the ink 325j and ink 325k being piled up, the height of ink 325 relative to the receiving surface 100a becomes height h12, which is higher than height h11.

[0150] In 3rd, which represents the third ejection, ink 325m is applied onto ink 325j and ink 325k that have been applied to the receiving surface 100a. As a result of ink 325j, ink 325j, and ink 325m being piled up, the height of ink 325 relative to the receiving surface 100a becomes height h13, which is even higher than height h12.

[0151] As described above, in this embodiment, the head 300 ejects ink multiple times so that the ink 325 is piled up in the height direction on the receiving surface 100a. The output unit 57 also outputs nozzle ejection abnormality information Ne detected based on the shape of the ink 325 piled up on the receiving surface 100a. This allows the liquid ejection device 1000a to ensure a height h of the ink 325 that is sufficient for detecting ejection abnormalities, ensuring high accuracy in detecting nozzle ejection abnormalities. Other effects are the same as those of the first embodiment.

[0152] [Other Preferred Embodiments] The liquid ejection device 1000 or 1000a can be used for a variety of purposes.

[0153] 17 is a diagram showing an example of application of the liquid discharger 1000 to a painting robot 8000. The painting robot 8000 paints the body of an automobile.

[0154] The painting robot 8000 includes a robot arm 810 that has multiple joints that allow it to move freely like a human arm, and a head 820 that ejects ink at the tip of the robot arm 810. The robot arm 810 also includes a 3D sensor 830 near the head 820.

[0155] The painting robot 8000 may be an articulated robot with an appropriate number of axes, such as five, six, or seven. The painting robot 8000 detects the position of the head 820 relative to the object 100 (a vehicle body in this embodiment) using a 3D sensor 830, and moves the robot arm 810 based on the detection result to paint the object 100. In this case, the head 300 according to the embodiment may be used as the head 820.

[0156] Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and various modifications and improvements are possible within the scope of the present invention.

[0157] In the embodiment, the liquid ejected from the head 300 may be a solution, suspension, emulsion, ultraviolet-curable ink, or the like containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a polymerizable compound, a resin, a surfactant, or the like, a functionalizing material, a biocompatible material such as DNA, amino acids, proteins, or calcium, an edible material such as a natural colorant, etc. These may be used, for example, in inkjet ink, paint, surface treatment liquid, a liquid for forming components of electronic elements or light-emitting elements, a liquid for forming electronic circuit resist patterns, a material liquid for 3D modeling, etc.

[0158] The object 100 having the application surface 100a means an object to which a liquid adheres and sticks, or an object to which a liquid adheres and penetrates, etc. Specific examples include recording media such as car bodies, building materials, paper, recording paper, film, and cloth, electronic components such as electronic circuit boards and piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects to which a liquid adheres.

[0159] The embodiments also include a liquid ejection method. For example, the liquid ejection method is a liquid ejection method using a liquid ejection device that applies liquid to a receiving surface, in which the liquid ejection device applies the liquid ejected from a nozzle to the receiving surface using a head, and outputs ejection abnormality information for the nozzle detected based on the shape of the liquid applied to the receiving surface using an output unit. Such a liquid ejection method can achieve the same effects as the liquid ejection device described above.

[0160] The embodiments also include a program. For example, the program is a program executed by a liquid ejection device that applies liquid to a receiving surface, and causes the liquid ejection device to execute a process that applies the liquid ejected from a nozzle to the receiving surface using a head, and outputs, using an output unit, ejection abnormality information for the nozzle detected based on the shape of the liquid applied to the receiving surface. Such a program can achieve the same effects as the liquid ejection device described above.

[0161] Each function of the embodiments can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to perform each function by software, such as a processor implemented by an electronic circuit, as well as devices such as an ASIC (Application Specific Integrated Circuit), a DSP (Digital Signal Processor), an FPGA (Field Programmable Gate Array), and conventional circuit modules designed to perform each function described above. [Explanation of symbols]

[0162] 1 carriage 2 connectors 10. Housing 11 Supply port 12 Collection Port 51 Ink type acquisition unit 52 Ink amount determination unit 53 Discharge control section 54 Speed ​​determining section 55 Movement control section 56 Discharge abnormality detection unit 57 Output section 72 X-direction drive unit 82 Y-direction drive unit 92 Z-direction drive unit 100 objects 100a Granted surface 101 X-axis rail 102 Y-axis rail 103 Z-axis rail 110 Moving mechanism 120 sensors 170 Direction of movement 200 supply units 230 Compressor 300, 820 head 310 Dispensing Module 311 Nozzle plate 321, 321a~321e nozzles 322 Channel 324 Piezoelectric element 325, 325a~325m ink 500 control section 501 CPU 502 ROM 503 RAM 504 I / F 511 Storage section 512 Display section 513 Operation Panel 520 Ink Information 810 Robot Arm 830 3D sensor 1000 liquid dispensing device 8000 Painting Robot X direction Main scanning direction Y direction Sub-scanning direction d12, d13 interval L1~L5 Linear patterns (examples of predetermined patterns) m Ink amount Ne Discharge abnormality information Nn Abnormal discharge nozzle information S1~S15 shape h, h1~h13 Height U Type Information v, v1~v3 relative movement speed [Prior art documents] [Patent documents]

[0163] [Patent Document 1] Patent No. 6344862

Claims

1. A liquid ejection device that applies a liquid to a receiving surface, a head that applies the liquid ejected from a nozzle to the application surface; an output unit that outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface; a moving mechanism that moves the head and the application surface relatively along the surface of the application surface; a movement control unit that controls the relative movement by the movement mechanism, The movement control unit a relative movement speed of the movement mechanism is controlled to control the height of the liquid relative to the surface to be dispensed; The liquid ejection device is configured to make the relative movement speed slower as the amount of the liquid ejected from the head decreases.

2. a sensor that outputs shape information of the liquid applied to the application surface, The liquid ejection device according to claim 1 , wherein the output section outputs ejection abnormality information of the nozzle detected based on shape information of the liquid output from the sensor.

3. The liquid ejection apparatus according to claim 1 , wherein the liquid shape information includes height information of the liquid relative to the surface to which the liquid is applied.

4. The liquid ejection device according to claim 1 , wherein a contrast Ct between a brightness C1 of the color of the surface to which the liquid is applied and a brightness C2 of the color of the liquid is expressed by the following formula: Ct=Ct1 / Ct2≦4

5. The liquid ejection device according to claim 1 , wherein the liquid receiving surface is non-permeable.

6. the head ejects the liquid multiple times so that the liquid is piled up in a height direction on the application surface, The liquid ejection device according to claim 1 , wherein the output section outputs ejection abnormality information of the nozzle detected based on a shape of the liquid piled up on the receiving surface.

7. The nozzle discharge abnormality is non-ejection of the liquid from the nozzle; a liquid volume abnormality in which the amount of the liquid ejected from the nozzle deviates from a predetermined amount; a liquid direction abnormality in which the direction of the liquid ejected from the nozzle is deviated from a predetermined ejection direction; 7. The liquid ejection device according to claim 1, wherein the liquid ejection speed is at least one of: and a liquid velocity abnormality in which the velocity of the liquid ejected from the nozzle deviates from a predetermined velocity.

8. The head has a plurality of nozzles, The liquid ejection device according to claim 1 , wherein the nozzle ejection abnormality information includes information for identifying an ejection abnormality nozzle from among the plurality of nozzles.

9. the head forms a predetermined pattern on the surface to which the liquid is applied by ejecting the liquid from each of the plurality of nozzles; The liquid ejection device described in claim 8, wherein the output unit outputs abnormal ejection nozzle information identified based on a second position on the receiving surface where the height of the liquid constituting the predetermined pattern formed on the receiving surface relative to the receiving surface is lower than the height at a first position on the receiving surface.

10. The liquid ejection device according to claim 9 , wherein the predetermined pattern includes a plurality of linear patterns formed on the surface to which the liquid is applied by ejecting the liquid from each of the plurality of nozzles and extending in a predetermined pattern extension direction.

11. A liquid ejection device that applies liquid to a receiving surface, a head that applies the liquid ejected from a nozzle to the application surface; an output unit that outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface; a moving mechanism that moves the head and the application surface relatively along the surface of the application surface; a movement control unit that controls the relative movement by the movement mechanism, The movement control unit a relative movement speed of the movement mechanism is controlled to control the height of the liquid relative to the surface to be dispensed; The liquid ejection device is configured to make the relative movement speed slower as the surface tension of the liquid decreases.

12. A liquid ejection device that applies liquid to a receiving surface, a head that applies the liquid ejected from a nozzle to the application surface; an output unit that outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface; a moving mechanism that moves the head and the application surface relatively along the surface of the application surface; a movement control unit that controls the relative movement by the movement mechanism, The movement control unit a relative movement speed of the movement mechanism is controlled to control the height of the liquid relative to the surface to be dispensed; The liquid ejection device is configured to make the relative movement speed slower as the viscosity of the liquid decreases.

13. The liquid ejection device according to claim 1 , further comprising an ejection control unit that controls the height of the liquid relative to the receiving surface by controlling the amount of the liquid ejected from the head.

14. The liquid ejection device according to claim 13 , wherein the ejection control unit increases the amount of the liquid ejected from the head as the surface tension of the liquid decreases.

15. 15. The liquid ejection device according to claim 13, wherein the ejection control section increases the amount of the liquid ejected from the head as the viscosity of the liquid decreases.

16. A liquid ejection method using a liquid ejection device that applies liquid to a receiving surface, comprising: The liquid ejection device The liquid ejected from the nozzle is applied to the surface by the head; an output unit outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface; a moving mechanism moving the head and the surface to be applied relatively along the surface of the surface to be applied; a movement control unit that controls the relative movement by the movement mechanism; The movement control unit a relative movement speed of the movement mechanism is controlled to control the height of the liquid relative to the surface to be dispensed; A liquid ejection method, wherein the relative movement speed is slowed as the amount of the liquid ejected from the head decreases.

17. A program to be executed by a liquid ejection device that applies liquid to a receiving surface, The liquid ejected from the nozzle is applied to the surface by the head; an output unit outputs ejection abnormality information of the nozzle detected based on the shape of the liquid applied to the receiving surface; a moving mechanism that moves the head and the surface to be applied relatively along the surface of the surface to be applied; a movement control unit that controls the relative movement by the movement mechanism; The movement control unit a relative movement speed of the movement mechanism is controlled to control the height of the liquid relative to the surface to be dispensed; the relative movement speed is slowed as the amount of the liquid ejected from the head is reduced; A program that causes the liquid ejection device to execute a process.

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