Liquid ejection device and liquid ejection method

Abstract

To draw high-quality drawing object in a short time.SOLUTION: A liquid ejection device includes: an ejection nozzle that ejects a liquid; a carriage that holds the ejection nozzle; a conveying unit that conveys the carriage portion; and a control unit that controls drawing of drawing object using the ejection nozzle. In the control unit, a characteristic of an ejection nozzle used in an outer-edge drawing step of drawing an outer edge of the drawing object is different from a characteristic of an ejection nozzle used in an inner-part drawing step of drawing a portion inside the outer edge of the drawing object.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Document 1 below discloses a technique for improving painting quality, in which a contour line is drawn along the outer edge of a design surface, and then a surface painted portion, which is the inner portion excluding the outer edge, is drawn. Summary of the Invention [Problem to be solved by the invention]

[0003] However, in the technology of Patent Document 1, a common nozzle is used for the process of drawing the contour line and the process of drawing the surface coating area, so it is not possible to eject the optimal amount of paint in each process, and it is not possible to draw high-quality objects in a short amount of time.

[0004] SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional technology, an object of the present invention is to enable high-quality drawing objects to be drawn in a short time. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, a liquid ejection device according to one embodiment includes an ejection nozzle that ejects liquid, a carriage unit that holds the ejection nozzle, a transport unit that transports the carriage unit, and a control unit that controls the drawing of an object using the ejection nozzle, and the control unit has different characteristics for the ejection nozzle used in the outer edge drawing process that draws the outer edge of the object and the ejection nozzle used in the internal drawing process that draws the part inside the outer edge of the object. [Effects of the Invention]

[0006] According to the liquid ejection device of one embodiment, it is possible to draw a high-quality object in a short time. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of a coating device according to an embodiment. [Figure 2] Enlarged view of part A of the coating equipment shown in Figure 1 [Figure 3] A flowchart showing an example of a processing procedure by a control unit included in a coating device according to an embodiment. [Figure 4] FIG. 10 is a diagram illustrating an example of a procedure for forming a drawing object by a coating device according to an embodiment. [Figure 5] FIG. 1 is a diagram showing an example (first example) of drawing by a coating device according to an embodiment; [Figure 6] FIG. 10 is a diagram showing an example (second example) of drawing by the coating device according to an embodiment; [Figure 7] FIG. 10 is a diagram showing an example (third example) of drawing by the coating device according to an embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, an embodiment will be described with reference to the drawings.

[0009] (Configuration of the painting device 100) Fig. 1 is a diagram showing an example of the configuration of a coating apparatus 100 according to one embodiment. Fig. 2 is an enlarged view of part A of the coating apparatus 100 shown in Fig. 1. The coating apparatus 100 shown in Fig. 1 is an example of a "liquid ejection device" and can draw an object on the object by ejecting paint (an example of a "liquid") from the paint ejection unit 110 while moving the paint ejection unit 110 toward the object to be drawn (not shown) located forward (positive direction of the Z axis, direction of arrow D in the figure).

[0010] As shown in FIGS. 1 and 2, the coating device 100 includes a paint discharge unit 110, a carriage unit 120, a transport unit 130, and a control unit 140.

[0011] The paint discharging unit 110 has a plurality of discharge nozzles 111. The plurality of discharge nozzles 111 have different specifications (for example, nozzle diameter). As shown in FIG. 2, in this embodiment, the paint discharging unit 110 has three discharge nozzles 111-1, 111-2, and 111-3 arranged side by side in the vertical direction (Y-axis direction). All of the three discharge nozzles 111-1, 111-2, and 111-3 are capable of discharging paint in the forward direction (positive direction of the Z-axis, direction of arrow D in the figure). However, this is not limited thereto, and the paint discharging unit 110 may have two or four or more discharge nozzles 111. Each of the plurality of discharge nozzles 111 is a discharge nozzle (mainly an inkjet head or a bubble jet head) that can adjust the amount of paint discharged.

[0012] For example, when an inkjet head is used as the discharge nozzle 111, the discharge nozzle 111 is configured to have an ink chamber, a discharge port, an inlet, and an actuator (for example, a piezoelectric element). In this case, in the discharge nozzle 111, a storage container that stores paint is pressurized by a pressurizing means, and paint is supplied from the storage container through the inlet into the ink chamber. Furthermore, in the discharge nozzle 111, a voltage is applied to the actuator, and the paint in the ink chamber is pressurized by the actuator, causing the paint to be discharged from the ink chamber through the discharge port.

[0013] Furthermore, for example, when a bubble jet head is used as the discharge nozzle 111, the discharge nozzle 111 is configured to have an inlet, an ink chamber, a flow path, a discharge port, an inlet, and a heating element. In this case, the discharge nozzle 111 boils the paint in the flow path using the heating element, generating bubbles in the paint in the flow path, and thereby allowing an amount of paint corresponding to the volume of the bubbles to be discharged from the discharge port.

[0014] The carriage portion 120 holds the paint discharge portion 110. Specifically, the carriage portion 120 is held by a Z-axis transport rail 133, which will be described later, so as to be movable in the front-rear direction (Z-axis direction).

[0015] The transport unit 130 is capable of transporting the carriage unit 120 in each of three mutually orthogonal axial directions (X-axis, Y-axis, and Z-axis). Specifically, the transport unit 130 has an X-axis transport rail 131, a Y-axis transport rail 132, and a Z-axis transport rail 133.

[0016] The X-axis transfer rail 131 is a rail that extends linearly in the left-right direction (X-axis direction).

[0017] The Y-axis conveying rail 132 is a rail that extends linearly in the vertical direction (Y-axis direction) and is supported by the X-axis conveying rail 131 so as to be movable in the horizontal direction (X-axis direction).

[0018] The Z-axis conveying rail 133 is a rail that extends linearly in the front-to-rear direction (Z-axis direction). The Z-axis conveying rail 133 is supported by the Y-axis conveying rail 132 so as to be movable in the up-and-down direction (Y-axis direction). The Z-axis conveying rail 133 holds the carriage unit 120 so as to be movable in the front-to-rear direction (Z-axis direction).

[0019] The transport unit 130 is configured to be able to rotate the carriage unit 120 in each of the pitch, roll, and yaw directions in addition to the three axes (X-axis, Y-axis, and Z-axis) mentioned above.

[0020] The control unit 140 controls the drawing of an object using the discharge nozzle 111. Specifically, the control unit 140 controls the transport of the carriage unit 120 in each of the three axial directions (X-axis, Y-axis, and Z-axis) by the transport unit 130 and the discharge of paint by the discharge nozzle 111, thereby moving the discharge nozzle 111 toward an object to be drawn that is located in front (positive direction of the Z-axis) and discharging paint from the discharge nozzle 111, thereby drawing an object on the object to be drawn.

[0021] For example, the control unit 140 can move the carriage unit 120 in the left-right direction (X-axis direction) by sending a control signal to a drive motor (not shown) for driving the Y-axis conveying rail 132, thereby moving the Y-axis conveying rail 132 in the left-right direction (X-axis direction) along the X-axis conveying rail 131.

[0022] Furthermore, for example, the control unit 140 can move the carriage unit 120 in the vertical direction (Y-axis direction) by sending a control signal to a drive motor (not shown) for driving the Z-axis conveying rail 133, thereby moving the Z-axis conveying rail 133 in the vertical direction (Y-axis direction) along the Y-axis conveying rail 132.

[0023] Furthermore, for example, the control unit 140 can move the carriage unit 120 in the forward and backward directions (Z-axis direction) along the Z-axis conveying rail 133 by sending a control signal to a drive motor (not shown) for driving the carriage unit 120.

[0024] In addition to being able to move the carriage unit 120 in each of the three axial directions (X-axis, Y-axis, and Z-axis) mentioned above, the control unit 140 can also rotate the carriage unit 120 in each of the pitch, roll, and yaw directions.

[0025] Each function of the control unit 140 can be realized by one or more processing circuits. Here, the term "processing circuit" in this specification includes a processor programmed to execute 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), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array), and conventional circuit modules designed to execute each function described above.

[0026] (Procedure for forming a drawing object using the coating device 100) Fig. 3 is a flowchart showing an example of a procedure of processing by the control unit 140 included in the coating apparatus 100 according to one embodiment. Fig. 4 is a diagram showing an example of a procedure of forming a drawn object by the coating apparatus 100 according to one embodiment.

[0027] First, the control unit 140 acquires drawing information for drawing a drawing object (step S301). For example, the control unit 140 acquires the drawing information from a higher-level application (e.g., a painting job execution application). For example, in the example shown in FIG. 4(a), the drawing information 401 of the drawing object 400 includes the outer edge shape of the drawing object. Furthermore, the drawing information 401 may include information such as color.

[0028] Next, the control unit 140 selects a discharge nozzle 111 suitable for drawing the outer edge portion from the plurality of discharge nozzles 111 (step S302). Here, the coating device 100 may select a discharge nozzle 111 that has been set in advance for the outer edge portion, or may select a suitable discharge nozzle 111 based on the drawing information.

[0029] Next, the control unit 140 executes an outer edge drawing step of drawing the outer edge of the object using the discharge nozzle 111 selected in step S302 based on the drawing information acquired in step S301 (step S303). Specifically, the control unit 140 draws the outer edge of the object by discharging paint from the discharge nozzle 111 while moving the discharge nozzle 111 along the outer edge of the object. For example, in the example shown in FIG. 4(b), the outer edge drawing step is executed, and as a result, an outer edge 402 of the object 400 is drawn.

[0030] Next, the control unit 140 selects a discharge nozzle 111 suitable for drawing the internal drawing region from among the plurality of discharge nozzles 111 (step S304). Here, the coating apparatus 100 may select a discharge nozzle 111 that has been set in advance for the internal drawing region, or may select a suitable discharge nozzle 111 based on the drawing information.

[0031] Next, the control unit 140 executes an internal drawing step (step S305) in which the control unit 140 draws an internal drawing area, which is a portion inside the outer edge of the drawing object, along the outer edge of the drawing object, using the discharge nozzle 111 selected in step S304 based on the drawing information acquired in step S301. Specifically, the control unit 140 draws the internal drawing area of ​​the drawing object by discharging paint from the discharge nozzle 111 while moving the discharge nozzle 111 along the outer edge within the internal drawing area.

[0032] Next, the control unit 140 determines whether all the internal drawing steps have been completed (step S306). For example, the control unit 140 can draw (i.e., fill in) the entire internal drawing area of ​​the drawing object by executing the internal drawing step multiple times.

[0033] In step S306, if it is determined that all the interior drawing steps have not been completed (step S306: No), the control unit 140 returns the process to step S303.

[0034] On the other hand, if it is determined in step S306 that all of the interior drawing steps have been completed (step S306: Yes), the control unit 140 ends the series of processes shown in Fig. 3. For example, in the example shown in Fig. 4(c), as a result of all of the interior drawing steps being completed, the interior drawing area 403 inside the outer edge 402 of the drawing object 400 is drawn in the specified color.

[0035] In this way, according to the coating device 100 of one embodiment, the object can be drawn by moving the discharge nozzle 111 along the outer edge of the object, and therefore, compared to a general serial scanning recording device, it is possible to finish the edge of the outer edge more beautifully.

[0036] (Example of painting by the painting device 100 (first example)) FIG. 5 is a diagram showing an example (first example) of drawing by the coating device 100 according to one embodiment.

[0037] As shown in Figure 5, the painting device 100 of one embodiment can form a drawing object 400 by drawing an outer edge 402 along the outer edge 402 in an outer edge drawing process, and then drawing an internal drawing area 403 inside the outer edge 402 along the outer edge 402 in an internal drawing process, under the control of the control unit 140.

[0038] 5, the coating apparatus 100 according to one embodiment can differentiate the characteristics of the discharge nozzle 111 used in the outer edge drawing process from the characteristics of the discharge nozzle 111 used in the inner edge drawing process by controlling the control unit 140. Here, the characteristics of the discharge nozzle 111 that are differentiated include, for example, the thickness of the line width (thick or thin), the length of the open time per unit time (long or short), etc.

[0039] For example, in one embodiment of the painting device 100, an ejection nozzle 111 capable of drawing narrow lines is used in the outer edge drawing process, and an ejection nozzle 111 capable of drawing wide lines is used in the internal drawing process.

[0040] Additionally, the coating device 100 according to one embodiment can, under the control of the control unit 140, set different parameters of the discharge nozzle 111 between the outer edge drawing process and the inner edge drawing process.

[0041] For example, the coating device 100 according to one embodiment can use suitable parameters in the outer edge drawing step so that fine lines can be drawn with less satellites and mist.

[0042] On the other hand, the coating device 100 according to one embodiment can use suitable parameters in the internal drawing process so as to discharge a larger amount of paint and draw thicker lines.

[0043] The various parameters include, for example, the nozzle diameter of the discharge nozzle 111, the driving amount of the movable parts of the discharge nozzle 111 (for example, the needle lift amount in a bubble jet head), the voltage waveform applied to the discharge nozzle 111, and the pressure applied to the discharge nozzle 111 or the storage container that stores the paint.

[0044] For example, in one embodiment of the coating device 100, in the outer edge drawing process, it is possible to perform drawing suitable for the outer edge drawing process by adopting at least one of the following: making the nozzle diameter of the discharge nozzle 111 smaller than in the internal drawing process; reducing the amount of drive of the movable parts of the discharge nozzle 111; shortening the open time per unit time of the discharge nozzle 111, which is determined by the voltage waveform applied to the discharge nozzle 111; or lowering the pressure applied to the discharge nozzle 111 or the storage container that stores the paint.

[0045] On the other hand, in the coating device 100 according to one embodiment, in the internal drawing process, it is possible to perform drawing suitable for the internal drawing process by adopting at least one of the following measures compared to the outer edge drawing process: making the nozzle diameter of the discharge nozzle 111 thicker; increasing the driving amount of the movable parts of the discharge nozzle 111; lengthening the open time per unit time of the discharge nozzle 111, which is determined by the voltage waveform applied to the discharge nozzle 111; or increasing the pressure applied to the discharge nozzle 111 or the storage container for storing the paint.

[0046] The suitable setting values ​​of the various parameters described above may be determined in advance by simulation, actual machine tests, etc., or may be adjusted depending on the characteristics of the paint, the object to be actually drawn, etc.

[0047] In the coating device 100 according to one embodiment, a spray gun type discharge nozzle 111 is used in the internal drawing step, so that a larger amount of paint can be discharged to draw thicker lines.

[0048] In this way, the painting device 100 according to one embodiment uses different discharge nozzles 111 in the outer edge drawing process and the inner drawing process, thereby enabling drawing using suitable discharge nozzle 111 characteristics in each of the outer edge drawing process and the inner drawing process, and as a result, high-quality objects can be drawn in a short time.

[0049] (Example of painting by the painting device 100 (second example)) FIG. 6 is a diagram showing an example (second example) of drawing by the coating device 100 according to an embodiment.

[0050] As shown in Figure 6, in one embodiment, the painting device 100, under the control of the control unit 140, draws the outer edge 402 along the outer edge 402 in the outer edge drawing process, and then executes multiple internal drawing processes, thereby sequentially drawing multiple drawing lines 403A (thick lines) along the outer edge 402 in the internal drawing area 403 inside the outer edge 402, thereby filling in the internal drawing area 403 and forming the drawing object 400.

[0051] At this time, as shown in FIG. 6, the painting device 100 according to one embodiment can, under the control of the control unit 140, overlap a portion of the drawing line 403A drawn in the subsequent internal drawing process with the drawing line 403A drawn in the previous internal drawing process.

[0052] As a result, the painting device 100 of one embodiment can prevent gaps (i.e., unpainted areas) from occurring between the drawing lines 403A due to variations in the discharge amount of the discharge nozzle 111, variations in the carriage movement accuracy, etc.

[0053] If the width of the overlapping area between two adjacent drawing lines 403A is too large, the number of drawing lines 403A required increases, which may reduce productivity. Therefore, the width of the overlapping area is preferably, for example, 1 / 2 to 1 / 3 or less of the width of the drawing lines 403A.

[0054] In addition, in one embodiment of the coating device 100, under the control of the control unit 140, a portion of the drawing line 403A drawn in the subsequent internal drawing process may be overlapped with the outer edge 402 drawn in the outer edge drawing process.

[0055] (Third example of drawing by the painting device 100) FIG. 7 is a diagram showing an example (third example) of drawing by the coating device 100 according to an embodiment.

[0056] As shown in Figure 6, in one embodiment of the painting device 100, under the control of the control unit 140, the end position of drawing the outer edge portion 402 can be moved to an internal drawing area 403 that is more inward than the outer edge portion 402 during the outer edge portion drawing process.

[0057] Similarly, in one embodiment of the painting device 100, under the control of the control unit 140, the starting position for drawing the outer edge 402 can be moved to an inner drawing area 403 that is more inward than the outer edge 402 during the outer edge drawing process.

[0058] As a result, in one embodiment of the painting device 100, even if the paint discharge is unstable at the start and end of the paint discharge during the outer edge drawing process, the area drawn by this unstable discharge can be filled in during the subsequent internal drawing process.

[0059] In addition, the coating device 100 according to one embodiment may be configured to decelerate the moving speed of the discharge nozzle 111 at least either at the start or end of drawing the outer edge portion 402 under the control of the control unit 140.

[0060] (effect) As described above, the painting device 100 according to one embodiment comprises a discharge nozzle 111 that discharges a liquid (paint), a carriage unit 120 that holds the discharge nozzle 111, a transport unit 130 that transports the carriage unit 120, and a control unit 140 that controls the drawing of an object using the discharge nozzle 111, and the control unit 140 has different characteristics for the discharge nozzle 111 used in the outer edge drawing process that draws the outer edge of the object and the discharge nozzle 111 used in the internal drawing process that draws the part inside the outer edge of the object.

[0061] As a result, the coating apparatus 100 according to one embodiment can use the characteristics of the discharge nozzle 111 that are suitable for drawing in both the outer edge drawing process, which draws the outer edge of the object, and the interior drawing process, which draws the part inside the outer edge of the object (the interior drawing area). For example, in the outer edge drawing process, a discharge nozzle 111 that can draw the outer edge with high resolution can be used, and in the interior drawing process, a discharge nozzle 111 that can discharge a large amount of paint per unit time and quickly fill in the interior drawing area can be used. Therefore, the coating apparatus 100 according to one embodiment can discharge the optimal amount of paint in each process, thereby allowing high-quality objects to be drawn in a short time.

[0062] In the coating device 100 according to one embodiment, the control unit 140 can perform the outer edge drawing process and the inner edge drawing process using the discharge nozzles 111 having different nozzle diameters.

[0063] As a result, the coating device 100 according to one embodiment can use the discharge nozzle 111 with a suitable nozzle diameter in both the outer edge drawing process and the inner drawing process, thereby making it possible to draw a high-quality object in a short time.

[0064] Furthermore, in the coating device 100 according to one embodiment, the control unit 140 can change the driving amount of the movable parts of the discharge nozzle 111 between the outer edge drawing process and the inner edge drawing process.

[0065] As a result, the painting device 100 according to one embodiment can set the driving amount of the movable parts of the discharge nozzle 111 to an appropriate driving amount in both the outer edge drawing process and the internal drawing process, thereby enabling high-quality drawing objects to be drawn in a short time.

[0066] Furthermore, in the coating device 100 according to one embodiment, the control unit 140 can make the voltage waveform applied to the discharge nozzle 111 different between the outer edge drawing process and the inner drawing process.

[0067] As a result, the painting device 100 according to one embodiment can set the opening time of the discharge nozzle 111 to an appropriate opening time in both the outer edge drawing process and the inner drawing process, thereby enabling high-quality drawing objects to be drawn in a short time.

[0068] Furthermore, in the coating device 100 according to one embodiment, the control unit 140 can vary the pressure applied to the discharge nozzle 111 or the storage container that stores the paint between the outer edge drawing process and the inner edge drawing process.

[0069] As a result, the painting device 100 according to one embodiment can apply an appropriate pressure to the discharge nozzle 111 or the storage container in both the outer edge drawing process and the inner drawing process, thereby enabling high-quality drawing objects to be drawn in a short time.

[0070] In addition, in the coating device 100 according to one embodiment, the control unit 140 can use a spray gun type discharge nozzle 111 in the internal drawing step.

[0071] As a result, the painting device 100 of one embodiment can draw (i.e., fill in) the part inside the outer edge of the drawing object (internal drawing area) in a short time during the internal drawing process, thereby allowing high-quality drawing objects to be drawn in a short time.

[0072] Furthermore, in one embodiment of the painting device 100, the control unit 140 can vary the number of discharge nozzles 111 used to draw the drawing object in the internal drawing process depending on the characteristics of the drawing area in which the drawing object is drawn (e.g., the area, width, length, shape, character type, image to be drawn, drawing area information, etc.) of the internal drawing area.

[0073] As a result, the coating device 100 according to one embodiment can selectively use a plurality of suitable discharge nozzles 111 in the internal drawing process, thereby making it possible to draw a high-quality object in a short time.

[0074] Furthermore, in the coating device 100 according to one embodiment, the control unit 140 can perform drawing of a drawing area in a subsequent process by overlapping it with a part of a drawing area drawn in a previous process.

[0075] As a result, the painting device 100 of one embodiment can prevent gaps (i.e., unpainted areas) from occurring between the drawing area drawn in the previous process and the drawing area drawn in the next process, thereby enabling high-quality objects to be drawn in a short amount of time.

[0076] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

[0077] Furthermore, a liquid ejection method according to one embodiment is a liquid ejection method using a liquid ejection device that includes an ejection nozzle 111 that ejects paint, a carriage unit 120 that holds the ejection nozzle 111, and a transport unit 130 that transports the carriage unit 120, and includes an outer edge drawing process that draws the outer edge of the object to be drawn, and an internal drawing process that draws a portion of the object that is inside the outer edge, and the characteristics of the ejection nozzle 111 used in the outer edge drawing process are different from the characteristics of the ejection nozzle 111 used in the internal drawing process.

[0078] As a result, the liquid discharging method according to one embodiment can use the characteristics of the discharge nozzle 111 that are suitable for drawing in both the outer edge drawing process, which draws the outer edge of the object to be drawn, and the interior drawing process, which draws the part inside the outer edge of the object to be drawn (the interior drawing region). For example, in the outer edge drawing process, a discharge nozzle 111 that can draw the outer edge with high resolution can be used, and in the interior drawing process, a discharge nozzle 111 that can discharge a large amount of paint per unit time and quickly fill in the interior drawing region can be used. Therefore, according to the liquid discharging method according to one embodiment, the optimum amount of paint can be discharged in each process, making it possible to draw a high-quality object in a short time. [Explanation of symbols]

[0079] 100 Painting equipment (liquid ejection equipment) 110 Paint discharge part 111, 111-1, 111-2, 111-3 Discharge nozzle 120 Carriage section 130 Conveying section 131 X-axis transport rail 132 Y-axis transport rail 133 Z-axis transport rail 140 Control Unit 400 drawings 401 Drawing Information 402 outer edge 403 Internal drawing area 403A Drawing Line [Prior art documents] [Patent documents]

[0080] [Patent Document 1] Patent No. 6775101

Claims

1. a discharge nozzle for discharging a liquid; a carriage portion that holds the discharge nozzle; a conveying unit that conveys the carriage unit; a control unit that controls drawing of a drawing object using the discharge nozzle; Equipped with The control unit drawing the outer edge of the object by ejecting the liquid from the ejection nozzle while transporting the ejection nozzle along the outer edge of the object; The characteristics of the discharge nozzle used in an outer edge drawing process for drawing the outer edge of the object to be drawn are different from the characteristics of the discharge nozzle used in an inner edge drawing process for drawing a portion inside the outer edge of the object to be drawn. A liquid ejection device characterized by:

2. The control unit The outer edge drawing step and the inner edge drawing step are performed using the discharge nozzles having different nozzle diameters. The liquid ejection device according to claim 1 .

3. The control unit The driving amount of the movable part of the discharge nozzle is made different between the outer edge drawing process and the inner edge drawing process.

3. The liquid ejection device according to claim 1, wherein the ejection head is a nozzle.

4. The control unit The voltage waveform applied to the discharge nozzle is made different between the outer edge drawing step and the inner edge drawing step.

4. The liquid ejection device according to claim 1, wherein the ejection head is a nozzle.

5. The control unit The pressure applied to the discharge nozzle or the storage container for storing the liquid is made different between the outer edge drawing process and the inner edge drawing process.

5. The liquid ejection device according to claim 1, wherein the ejection head is a nozzle.

6. The control unit In the internal drawing process, the spray gun type discharge nozzle is used. The liquid ejection device according to any one of claims 1 to 5.

7. The control unit In the internal drawing step, the number of the discharge nozzles used for drawing the object is varied depending on the characteristics of a drawing area where the object is to be drawn. The liquid ejection device according to any one of claims 1 to 6.

8. The control unit The drawing area of ​​the next process is drawn by overlapping it with part of the drawing area drawn in the previous process. The liquid ejection device according to any one of claims 1 to 6.

9. A liquid ejection method using a liquid ejection device including an ejection nozzle that ejects liquid, a carriage unit that holds the ejection nozzle, and a transport unit that transports the carriage unit, comprising: an outer edge drawing step of drawing the outer edge of the object by ejecting the liquid from the ejection nozzle while transporting the ejection nozzle along the outer edge of the object; an inner drawing step of drawing a portion of the object that is inside the outer edge; Including, The characteristics of the discharge nozzle used in the outer edge drawing process and the characteristics of the discharge nozzle used in the inner edge drawing process The characteristics of the discharge nozzle are different A liquid ejection method comprising:

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