JP7691640B2 - LIQUID DISCHARGE APPARATUS AND LIQUID DISCHARGE METHOD - Google Patents

Description

The present invention relates to a liquid ejection device and a liquid ejection method.

Patent document 1 describes a liquid ejection device that includes a carriage 5 equipped with a recording head 10 that ejects liquid, and a scanning means for scanning the carriage 5 in the main scanning direction, in which the carriage 5 has a jam detection sensor 16 that detects contact with the recording medium P, and a lifting means that moves the recording head 10 to vary the distance between the recording head 10 and the recording medium P, and describes a configuration in which, when the detection means detects contact, it simultaneously performs an operation to stop the scanning of the carriage 5 by the scanning means, and an operation to increase the distance between the recording head 10 and the recording medium P by the lifting means.

The object of the present invention is to provide a liquid ejection device that can prevent collision between an object and a liquid ejection unit during liquid ejection.

The present invention provides a liquid ejection device including a liquid ejection port that ejects liquid toward a target object, and a liquid ejection unit that is movable in at least one of a first direction and a second direction intersecting the first direction, and a third direction that intersects the first direction and the second direction and is parallel to the direction in which the liquid is ejected from the liquid ejection port toward the target object, the liquid ejection device including a contact detection unit having a position detection means that detects the position of the liquid ejection unit relative to the target object, and a control means that controls movement of the liquid ejection unit, and the liquid ejection unit ejects the liquid toward the target object. and a standby position which is farther from the target in the third direction than the ejection position, the contact detection unit is attached to the liquid ejection unit in the standby position so as to cover the liquid ejection port, and the control means calculates a movement trajectory of the liquid ejection unit when ejecting liquid onto the target after the position detection means detects the position of the liquid ejection unit relative to the target, and performs a first operation of moving the liquid ejection unit along the calculated movement trajectory before the liquid ejection unit ejects liquid onto the target.

The present invention provides a liquid ejection device that can prevent collisions between an object and a liquid ejection unit during liquid ejection.

1 is a schematic diagram illustrating the overall configuration of a liquid ejection apparatus according to the present invention. FIG. 4 is a perspective view showing a state in which the carriage is at a standby position on the Z axis. FIG. 4 is a perspective view showing a state in which the carriage is at an ink ejection position on the Z axis. FIG. 4 is a perspective view showing a state in which a contact detection unit is attached to a carriage. FIG. FIG. FIG. 4 is a perspective view of the contact detection unit as seen from the rear side. 4A and 4B are explanatory views of a first detection member and a second detection member of the contact detection unit. FIG. 4 is a perspective view of a first detection member and a second detection member. FIG. 4 is an explanatory diagram of an electrical connection relationship of the contact detection unit. FIG. 4 is a block diagram of a portion relating to carriage movement control. FIG. 4 is an explanatory diagram showing the relationship between an object to be drawn and a drawing area. FIG. FIG. 4 is an explanatory diagram showing an example of an electrical connection state of a contact detection unit. FIG. 13 is an explanatory diagram for automatically acquiring coordinate information of an object to be drawn. FIG. 4 is an explanatory diagram showing the relationship between position measurement and the surface shape of an object to be drawn. 5A and 5B are explanatory diagrams showing the relationship between a detection surface of a contact detection unit and a liquid ejection surface. 13 is an explanatory diagram when the size of the detection surface of the contact detection unit is changed. FIG. 2 is an overall flow diagram of the liquid ejection device. Location information verification flow chart. 5A and 5B are explanatory diagrams showing the positional relationship of the carriage during verification and during ink ejection. FIG. 13 is an explanatory diagram showing an example in which a protrusion is detected in verification. FIG. 4 is an explanatory diagram showing an example of an electrical connection state of a series connection circuit. FIG. 4 is an explanatory diagram showing an example of a movement trajectory of a carriage. FIG. 21 is a detailed flow diagram of part A of the verification flow of FIG. 20 . FIG. 4 is an explanatory diagram showing an example of a display screen of an operation panel of the liquid ejection device. 11A and 11B are explanatory diagrams of a fall prevention member for a second detection member of the contact detection unit. 11 is an explanatory diagram of a liquid ejection device according to a modified example of the present invention. FIG. 13 is an enlarged perspective view of the liquid ejection device according to the modified example. FIG. 1 is an explanatory diagram showing an application example of the present invention. FIG. 1 is an explanatory diagram showing an application example of the present invention. FIG. 1 is an explanatory diagram showing an application example of the present invention.

An embodiment of the present invention is described below with reference to the drawings.

Figure 1 is a schematic diagram of the overall configuration of a liquid ejection device of the present invention. Figure 1(a) is a side view of the liquid ejection device, and Figure 1(b) is a plan view of the same device.

The liquid ejection device 1000 is installed facing the drawing target 100. The liquid ejection device 1000 includes an X-axis rail 101, a Y-axis rail 102 that intersects with the X-axis rail 101, and a Z-axis rail 103 that intersects with the X-axis rail 101 and the Y-axis rail 102. The Y-axis rail 102 holds the X-axis rail 101 so that the X-axis rail 101 can move in the Y-axis direction. The X-axis rail 101 holds the Z-axis rail 103 so that the Z-axis rail 103 can move in the X-axis direction. The Z-axis rail 103 holds the carriage 70 so that the carriage 70 can move in the Z-axis direction.

Here, the X-axis is an example of a first direction. The Y-axis is an example of a second direction that intersects with the first direction. The Z-axis is an example of a third direction that intersects with the first and second directions. The carriage 70 is an example of a liquid ejection unit, and the carriage 70 is equipped with a head 300 for ejecting ink, which is an example of a liquid, toward the drawing object 100.

The carriage 70 is provided with a Z-direction drive unit 92 that drives the carriage 70 in the Z-axis direction along the Z-axis rail 103. The Z-axis rail 103 is provided with an X-direction drive unit 72 that drives the Z-axis rail 103 in the X-axis direction along the X-axis rail 101. Furthermore, the X-axis rail 101 is provided with a Y-direction drive unit 82 that drives the X-axis rail 101 in the Y-axis direction along the Y-axis rail 102.

With the above configuration, the liquid ejection device 1000 ejects ink from the head 300 toward the object 100 to be drawn, while moving the carriage 70 in the X-axis, Y-axis, and Z-axis directions based on the drawing data, thereby drawing on the object 100.

Note that the movement of the carriage 70 in the Z-axis direction does not have to be parallel to the Z-axis, and may be diagonal as long as it includes at least a Z-axis component.

The object 100 to be drawn is not limited to a flat surface. The object 100 to be drawn may be a nearly vertical surface, such as the body of a car or truck, or the body of an aircraft, or a surface with a large radius of curvature.

Next, the configuration of the carriage 70 will be described.

Figure 2 is a perspective view showing the carriage in a standby position on the Z axis.

The carriage 70 can move in the Z-axis direction along the Z-axis rail 103 by power from the Z-direction drive unit 92.

The carriage 70 is equipped with a head fixing plate 7 for mounting the heads 300. Figure 2 shows an example of mounting a yellow head 300Y, a magenta head 300M, a cyan head 300C, a black head 300K, a white head 300W, and a special color head 300S on the head fixing plate 7. Hereinafter, these heads will be referred to collectively as heads 300.

Each of the heads 300Y, 300M, 300C, 300K, 300W and 300S has a nozzle surface 302a having a plurality of nozzles 302.

Here, the nozzle 302 is an example of a liquid ejection port, and the nozzle surface 302a is an example of a liquid ejection surface.

The types and number of ink colors used in the head 300 are not limited to those described above. For example, all inks used in the head 300 may be the same color.

The head 300 is fixed to the head fixing plate 7 with the nozzle surface 302a intersecting the horizontal plane (X-Z plane) and the arrangement direction of the multiple nozzles 302 tilted with respect to the X-axis. This causes the nozzles 302 to eject ink in a direction intersecting the direction of gravity (Z direction).

In FIG. 2, reference numeral 4 denotes a cleaning unit for cleaning the head 300.

The cleaning unit 4 moves in a direction parallel to the X-axis along a guide rail 9R fixed to the frame 80.

Although not shown, a motor for moving the cleaning unit 4 along the guide rail 9R, a position sensor for detecting the position of the cleaning unit 4 on the X-axis (standby position, return position), etc. are arranged inside the frame 80.

As a result, the motor transmits power to the belt 14 shown in FIG. 2, and the cleaning unit 4 connected to the belt 14 moves in the positive X-axis direction along the guide rail 9R.

Then, the cleaning unit 4 cleans the nozzle surface 302a and the nozzle 302. When the cleaning unit 4 moves further in the positive X-axis direction and reaches the turning position, the direction of movement switches to the negative X-axis direction, and the cleaning unit 4 returns to the standby position.

Figure 3 is a perspective view showing the carriage in the ink ejection position on the Z axis.

The difference from Figure 2 is that the carriage 70 moves toward the drawing object 100 (positive side in the Z-axis direction).

The carriage 70 moves along the Z axis between an ink ejection position (Figure 3) where ink is ejected from the head 300 toward the drawing object 100, and a standby position (Figure 2) located away from the drawing object 100 relative to the ink ejection position.

The ink ejection position of the carriage 70 is not fixed, but is variable based on the drawing data.

Figure 4 is a perspective view showing the contact detection unit attached to the carriage.

The contact detection unit 200 includes a first detection member 210 that is detachable from the carriage 70, and a second detection member 220 that is detachable from the first detection member 210.

Here, the first detection member 210 is an example of a first member, and the second detection member 220 is an example of a second member. The configuration of the contact detection unit 200 will be described in detail below.

Figure 5 is a plan view of the carriage near the head. Figure 5(a) shows the state where the contact detection unit is not attached, and Figure 5(b) shows the state where the contact detection unit is attached to the carriage.

The contact detection unit 200 includes a first detection member 210 that is detachable from the carriage 70, and a second detection member 220 that is detachable from the first detection member 210.

The first detection member 210 is equipped with locking members 211a and 211b, which are detachable from an attachment portion (not shown) provided on the carriage 70. This allows the contact detection unit 200 to be detachable from the carriage 70.

The first detection member 210 is provided at a portion facing the head 300 with a head protection member 212 that corresponds to the position of each nozzle 302 of the head 300. The head protection member 212 covers each nozzle 302 while the contact detection unit 200 is attached to the carriage 70, preventing the nozzles 302 from drying out and preventing foreign matter from adhering to the nozzles 302.

Figure 6 is a plan view of the contact detection unit.

The same components as those described in Figure 5 are given the same reference numerals, and their description will be omitted.

The first detection member 210 is equipped with push switches 213a, 213b, 213c, and 213d. Hereinafter, these push switches will be collectively referred to as push switches 213. The push switches 213 are switches that operate in response to the movement of the second detection member 220 attached to the first detection member 210.

The push switch 213 is configured to be activated by the pressing force received from the second detection member 220 when the second detection member 220 moves in the negative Z-axis direction during position measurement of the surface of the drawing object 100. Details of the position measurement will be described later.

Here, the push switch 213 is an example of a position detection means.

Figure 7 is a perspective view of the contact detection unit from the rear.

The same reference numerals are used for components already described in Figures 5 and 6, and their description will be omitted.

The head protection member 212 provided on the first detection member 210 corresponds to the position of each nozzle 302 of the head 300 as shown in the figure, and is made of an elastic material such as sponge or rubber.

Figure 7 shows a configuration in which 48 head protection members 212 are provided corresponding to the 48 (8 x 6) nozzles 302. While the contact detection unit 200 is attached to the carriage 70, the head protection members 212 cover each nozzle 302 of the head 300, preventing the nozzles 302 from drying out and preventing foreign matter from adhering to the nozzles 302.

The number and arrangement of nozzles are not limited to those described above. The nozzles do not have to be arranged two-dimensionally vertically and horizontally as shown in the figure, but may be arranged in a row of nozzles arranged vertically or horizontally. Also, there may be only one nozzle instead of multiple nozzles.

Figure 8 is an explanatory diagram of the first and second detection members of the contact detection unit. Figures 8(a) and 8(b) show the first detection member, with Figure 8(a) being a front view of the member and Figure 8(b) being a perspective view of the member from the front. Figures 8(c) and 8(d) show the second detection member, with Figure 8(c) being a rear view of the member and Figure 8(d) being a perspective view of the member from the rear.

As shown in Figures 8(a) and 8(b), the first detection member 210 is provided with magnets 214a, 214b, 214c, and 214d, which are an example of a means for generating magnetic force, on the front portion. The first detection member 210 is also provided with detection plates 215a and 215b on the front portion. Furthermore, the first detection member 210 is provided with locking members 211a and 211b that are used when mounting the first detection member 210 to the carriage 70. Hereinafter, these magnets will be collectively referred to as magnet 214.

On the other hand, as shown in Figures 8(c) and 8(d), the second detection member 220 is provided with magnets 224a, 224b, 224c, and 224d, which are an example of a means for generating magnetic force, on the rear surface of the second detection member 220. In addition, the second detection member 220 is provided with conductive leaf springs 225a and 225b on the rear surface of the second detection member 220. Hereinafter, these magnets will be collectively referred to as magnet 224.

The first detection member 210 and the second detection member 220 are attached so that the front part of the first detection member 210 faces the back part of the second detection member 220. The second detection member 220 is attached to the first detection member 210 by the magnetic force of the magnets 214 and 224.

The surface of the magnet 214 of the first detection member 210 protrudes slightly from the surrounding surface (the surface on which the magnet 214 is not installed). On the other hand, the surface of the magnet 224 of the second detection member 220 is slightly lower than the surrounding surface (the surface on which the magnet 224 is not installed). This makes the magnets 214 and 224 uneven, and when the second detection member 220 is attached to the first detection member 210, the relative positions of the first detection member 210 and the second detection member 220 are fixed in one place, making positioning easier.

When the second detection member 220 is attached to the first detection member 210, the leaf spring 225a of the second detection member 220 comes into contact with the detection plate 215a of the first detection member 210. The leaf spring 225b of the second detection member 220 comes into contact with the detection plate 215b of the first detection member 210.

Figure 9 is a perspective view of the first and second detection members.

As mentioned above, the first detection member 210 and the second detection member 220 are attached by the magnetic force of the magnets 214, 224 provided on both members. The magnetic force here is set to a strength that allows relative movement between the first detection member 210 and the second detection member 220 when an external force F is applied to the side of the second detection member 220 from the direction of the arrow, as shown in the figure.

The above-mentioned relative movement is used when the second detection member 220 detects obstacles such as protrusions present on the surface of the object to be drawn 100 in verifying the position information of the object to be drawn 100, which will be described later. When the second detection member 220 moves relative to the first detection member 210, the leaf springs 225a, 225b of the second detection member 220 move away from the detection plates 215a, 215b of the first detection member 210, and an electrical signal is output.

Here, the detection plates 215a and 215b are an example of an obstacle detection means.

Figure 10 is an explanatory diagram of the electrical connection relationship of the contact detection unit. Figure 10(a) is a schematic diagram showing the electrical connection relationship in the planar direction of the contact detection unit, and Figure 10(b) is a schematic diagram showing the electrical connection relationship in the front direction of the same unit.

The first detection member 210 is attached to the carriage 70 equipped with the head 300 by the locking members 211a and 211b (see FIG. 6). When the first detection member 210 is attached to the carriage 70, the pin-shaped connection terminals 216a and 216b provided on the first detection member 210 fit into the jack provided on the carriage 70, electrically connecting the first detection member 210 and the carriage 70.

The second detection member 220 is attached to the first detection member 210 by the magnetic force of magnets 214 and 224. When the second detection member 220 is attached to the first detection member 210, the detection plates 215a, 215b of the first detection member 210 and the leaf springs 225a, 225b of the second detection member 220 come into contact with each other, electrically connecting the two detection members 210, 220.

The detection plate 215a of the first detection member 210 is electrically connected to the connection terminal 216a via the push switches 213a and 213b. The other detection plate 215b is electrically connected to the connection terminal 216b via the push switches 213d and 213c. Hereinafter, these push switches will be collectively referred to as the push switches 213.

As described above, the push switch 213 and the detection plates 215a, 215b provided on the first detection member 210 and the leaf springs 225a, 225b provided on the second detection member 220 are connected in series to form a series connection circuit.

The serial connection circuit is configured to be electrically conductive when the first detection member 210 and the second detection member 220 are attached to the carriage 70 in the correct position. For example, the push switch 213 is on (conductive state) when not pressed and off (non-conductive state) when pressed.

When the push switch 213 is conductive, it detects that the first detection member 210 and the second detection member 220 are in the correct position, and when it is non-conductive, it detects that the first detection member 210 or the second detection member 220 is not in the correct position.

The configuration of the detection means is not limited to the above. Non-contact detection means such as optical sensors may be used instead of contact detection means such as push switches or detection plates. The number and arrangement of the detection means are also not limited to the above. They may be configured in an appropriate number and arrangement depending on the size of the carriage 70 and head 300, etc.

As described above, the push switch 213 used for position detection and the detection plates 215a, 215b used for obstacle detection are detachably mounted on the carriage 70.

This allows the push switch 213 and the detection plates 215a, 215b to be removed from the carriage 70 when they are not needed, preventing accidental damage to the push switch 213 and the detection plates 215a, 215b.

As described above, the push switch 213 and the detection plates 215a and 215b are integrally provided as the contact detection unit 200.

This allows the push switch 213 and the detection plates 215a, 215b to be easily attached and detached to the carriage 70. Also, different types of detection can be achieved with a single contact detection unit 200.

Figure 11 is a block diagram of the parts involved in carriage movement control.

The liquid ejection device 1000 includes a carriage 70, an X-direction drive unit 72, a Y-direction drive unit 82, a Z-direction drive unit 92, a contact detection unit 200, a control unit 500, a memory unit 501, a display unit 502, and an operation panel 503.

The carriage 70 is movable in the X-axis, Y-axis, and Z-axis directions relative to the drawing object 100, and the carriage 70 is equipped with a head 300 (see Figure 1) that ejects ink toward the drawing object 100.

The X-direction drive unit 72 drives the carriage 70 in the X-axis direction based on instructions from the control unit 500. The Y-direction drive unit 82 drives the carriage 70 in the Y-axis direction based on instructions from the control unit 500. The Z-direction drive unit 92 drives the carriage 70 in the Z-axis direction based on instructions from the control unit 500.

The contact detection unit 200 is a unit that is detachably attached to the carriage 70. The contact detection unit 200 is attached to the carriage 70 when measuring the position of the drawing target 100 prior to ink ejection onto the drawing target 100, and when verifying the position information obtained by the position measurement.

The contact detection unit 200 forms the above-mentioned serial connection circuit by being attached to the carriage 70, and the signal output by the contact detection unit 200 is transmitted to the control unit 500 via the carriage 70.

The control unit 500 includes a CPU that is responsible for the overall control of the liquid ejection device 1000, and a ROM that stores programs for executing control of the CPU for drawing operations and other fixed data. The control unit 500 also includes a RAM that temporarily stores drawing data and the like, and an I/F for transmitting and receiving data and signals used when receiving drawing data and the like from a host such as a PC. The control unit 500 is an example of a control means.

The control unit 500 also stores and reads out the detection results of the contact detection unit 200 in the memory unit 501. The control unit 50 also controls the X-direction drive unit 72, the Y-direction drive unit 82, and the Z-direction drive unit 92 to drive the carriage 70 in the X-axis direction, the Y-axis direction, and the Z-axis direction. The control unit 500 also controls the ejection of ink from the head 300 provided on the carriage 70.

Furthermore, if an abnormality occurs in the operation of the carriage 70, the head 300, or the like, the control unit 500 displays that fact on the display unit 502 to notify the user. The control unit 500 also accepts instructions from the operation panel 503 and performs processing.

The memory unit 501 stores position information (three-dimensional coordinate information) from position measurement by the contact detection unit 200, information on verification of the position information, etc.

If an abnormality occurs in the liquid ejection device 1000, the display unit 502 displays the details and notifies the user.

The operation panel 503 can be used to input values (coordinates) for specifying the drawing area 100a for the drawing target 100, the moving speed of the carriage 70, and the distance between the head 300 and the drawing target 100. In addition, the operation panel 503 can be used to specify three-dimensional coordinate information that indicates the surface shape of the drawing target 100. The display unit 502 and the operation panel 503 may be operated on a single screen using a touch panel or the like.

Next, we will explain position measurement using the contact detection unit 200.

Figure 12 is an explanatory diagram showing the relationship between the object to be drawn and the drawing area.

The object 100 to be drawn varies in size and shape, and the positional relationship between the liquid ejection device 1000 and the object 100 to be drawn varies depending on the installation conditions. Therefore, before ejecting ink onto the object 100 to be drawn, the liquid ejection device 1000 needs to grasp the positional information of the surface of the object 100 to be drawn.

For example, if the area to be drawn is a rectangular drawing area 100a as shown in the figure, the coordinate information of the drawing start position P1 and drawing end position P2 is stored in the memory unit 501 of the liquid ejection device 1000. This determines the drawing area 100a.

In this example, the coordinate information is XY coordinate information, but is not limited to the above. Depending on the installation state of the liquid ejection device 1000 and the object to be drawn 100, the liquid ejection device 1000 may be tilted relative to the object to be drawn 100, or there may be obstacles such as protrusions on the surface of the object to be drawn 100. For this reason, it is desirable to capture the coordinate information as three-dimensional coordinate information that includes a Z-direction component.

The drawing area 100a is the range in which the carriage 70 provided on the liquid ejection device 1000 moves. Note that just because the drawing area 100a is the range in which the carriage 70 moves does not necessarily mean that drawing is performed on the entire surface of the drawing area 100a. Also, there may be multiple drawing areas within the same drawing target 100 as long as they are within the range in which the carriage 70 can move.

If there is an obstacle such as a protrusion in the drawing area 100a, the position information of the obstacle must be stored in the memory unit 501. If the drawing target 100 is a truck body, an example of an obstacle would be a reinforcing rib on the body.

Next, we will explain the operation of measuring the position of the drawing area 100a of the drawing object 100 using the contact detection unit 200.

Figure 13 is an explanatory diagram of position measurement. Figure 13(a) is a plan view of the contact detection unit when it is separated from the drawing object, and Figure 13(b) is a plan view of the contact detection unit when it is in contact with the drawing object.

Prior to ejecting ink onto the drawing target 100, the liquid ejection device 1000 obtains position information of the drawing area 100a of the drawing target 100 and performs position measurement to grasp the surface shape of the drawing area 100a.

To measure the position, first, the carriage 70, which is in a standby position on the Z axis, is moved in the positive direction of the Z axis toward the object 100 to be drawn.

When the detection surface 220a of the second detection member 220 comes into contact with the drawing object 100, the second detection member 220 moves to the negative side in the Z axis direction. This movement of the second detection member 220 to the negative side in the Z axis direction causes the second detection member 220 to press the first detection member 210 to the negative side in the Z axis direction.

Next, when the first detection member 210 moves toward the negative side in the Z-axis direction, the first detection member 210 presses the push switch 213 toward the carriage 70. This activates the push switch 213, and the contact detection unit 200 detects the position of the surface of the drawing object 100.

Then, the position information of the carriage 70 at this time is stored in the memory unit 501 of the liquid ejection device 1000.

The above operation is performed multiple times from drawing start position P1 to drawing end position P2 of drawing area 100a to obtain information indicating the surface shape of drawing area 100a.

Figure 14 is an explanatory diagram showing an example of the electrical connection state of the contact detection unit.

The push switch 213 and the detection plates 215a, 215b provided on the first detection member 210 and the leaf springs 225a, 225b provided on the second detection member 220 form a series connection circuit.

Figure 14 shows the state in which push switch 213d, one of the four push switches, detects the surface position of the drawing target 100. The position and number of the push switches that are activated vary depending on the surface shape of the drawing target 100.

In the above configuration, the push switch 213 is turned off by the pressing force associated with the detection of the surface position of the drawing target 100. When the push switch 213 is turned off, the series connection circuit becomes non-conductive, and the coordinate information at that time is stored in the memory unit 501 as coordinate information indicating the surface position of the drawing target 100 at that position.

Figure 15 is an explanatory diagram of how to automatically obtain coordinate information for the object to be drawn.

After setting the drawing start position P1 and drawing end position P2 on the operation panel 503, the user sets the X grid line 100b and the Y grid line 100c with arbitrary numerical values. The settings here include specifying the number of grid lines or the spacing between the grid lines, etc.

After setting the X grid line 100b and the Y grid line 100c, the liquid ejection device 1000 measures the position of the surface of the object 100 to be drawn at the intersection of the X grid line 100b and the Y grid line 100c, and automatically obtains coordinate information (XYZ three-dimensional coordinate information).

Depending on the grid line setting value set by the user, the user can obtain coordinate information at fine or coarse intervals. Alternatively, the user may only set the drawing start position P1 and the grid line, and the drawing end position P2 may follow the grid. Furthermore, if there is an obstacle such as a protrusion that affects the drawing within the drawing area 100a of the drawing subject 100, the user may specify the XY coordinates of that part, measure its position, and add it to the coordinate information.

Figure 16 is an explanatory diagram showing the relationship between position measurement and the surface shape of the object to be drawn. Figure 16(a) shows a case where the surface of the object to be drawn is inclined, and Figures 16(b), (c), and (d) show a case where a protrusion exists on the surface of the object to be drawn.

As shown in FIG. 16(a), when the drawing object 100 is tilted relative to the liquid ejection device 1000, the coordinates between the two points, coordinates (Xm, Ym, Zm) and coordinates (Xn, Yn, Zn), are calculated proportionally. As a result, during the ink ejection operation, the carriage 70 moves along the tilt of the drawing object 100, so that the distance between the drawing object 100 and the head 300 remains constant.

When using the proportional calculation as above, there is a possibility that protrusions or steps between the coordinates (Xm, Ym, Zm) and (Xn, Yn, Zn) as shown in Figure 16 (b) will be recognized as slopes.

Also, as in Figure 16(c), if a protrusion is located exactly between the coordinates of two points, the protrusion may be overlooked. Furthermore, as in Figure 16(d), even if the presence of a protrusion is recognized at the position measurement stage, the carriage 70 may not be able to avoid the protrusion and may collide with it.

The reason this problem occurs is that the carriage 70 operates differently when measuring the position and when ejecting ink.

Position measurement is performed by moving the carriage 70 in the XY directions, and after the carriage 70 is positioned at the measurement location, moving the carriage 70 in the Z direction. In contrast, ink ejection onto the drawing target 100 is performed by continuously moving the carriage 70 in the XYZ directions while maintaining a constant distance between the drawing target 100 and the carriage 70.

Therefore, in the present invention, a process is provided to verify the position information obtained from the position measurement after the position measurement and before the ink ejection operation is performed.

In this verification, the carriage 70 is moved relative to the drawing object 100 according to coordinate information indicating the movement trajectory of the carriage 70 obtained based on the position information obtained in the position measurement, and it is checked whether any protrusions or the like that were overlooked in the position measurement have appeared. The operation of the carriage 70 during the verification is the same as that during the ink ejection operation, except that ink is not ejected. Therefore, if no new protrusions or the like appear in this verification, it is possible to prevent drawing failures during the actual ink ejection operation. Details of the verification will be described later.

Figure 17 is an explanatory diagram showing the relationship between the detection surface of the contact detection unit and the liquid ejection surface. Figure 17(a) shows the detection surface of the contact detection unit, and Figure 17(b) shows the liquid ejection surface of the carriage.

In FIG. 17(a), the contact detection unit 200 mounted on the carriage 70 includes a first detection member 210 and a second detection member 220. The position of the drawing object 100 is measured by contacting the detection surface 220a of the second detection member 220 with the surface of the drawing object 100.

On the other hand, the carriage 70 has nozzles 302, which are an example of a liquid ejection port, at the location where the contact detection unit 200 is located. In this example, a head 300 equipped with multiple nozzles 302 is attached to the carriage 70.

Here, the surface formed by the nozzle 302 is referred to as the liquid ejection surface and is represented by the symbol 302a.

Figure 17(b) illustrates a head 300 with 48 nozzles 302, with 8 nozzles 302 arranged in the X-axis direction and 6 in the Y-axis direction. In this example, the surface formed by these 48 nozzles 302 becomes the liquid ejection surface 302a. Alternatively, a surface shaped to correspond to the external shape of the head 300 may be used as the liquid ejection surface 302a.

The number and arrangement of the nozzles 302 are not limited to those described above. The nozzles 302 may be arranged in a row vertically or horizontally instead of in a two-dimensional array as shown in the figure. Also, there may be only one nozzle 302 instead of multiple nozzles.

Up to this point, the description has been based on an example in which the detection surface 220a of the second detection member 220 has a larger area than the liquid ejection surface 302a of the carriage 70. However, the height (Y-axis direction), width (X-axis direction), and thickness (Z-axis direction) of the detection surface 220a may be changed as appropriate depending on the surface shape and surface condition of the drawing object 100 for which position measurement is to be performed.

Here, the area of the detection surface 220a refers to the area of the projection surface of the detection surface 220a projected onto the liquid ejection surface 302a from the drawing object 100 side on the Z axis. For example, as shown in the figure, when the detection surface 220a has a larger area than the liquid ejection surface 302a, it can be said that the liquid ejection surface 302a exists within the projection surface of the detection surface 220a from the drawing object 100 side.

Figure 18 is an explanatory diagram of when the size of the detection surface of the contact detection unit is changed. Figure 18(a) shows the case where the detection surface of the second detection member is larger than the liquid ejection surface. Figure 18(b) shows the case where the detection surface of the same member is equal to the liquid ejection surface. Figure 18(c) shows the case where the detection surface of the same member is smaller than the liquid ejection surface.

As shown in FIG. 18(a), when the detection surface 220a of the second detection member 220 is larger than the liquid ejection surface 302a, it is possible to detect a wide range at once when measuring the position of the drawing target 100. Therefore, it is possible to detect the position of a drawing target that is entirely flat in a short time.

As shown in FIG. 18(b), when the detection surface 220a of the second detection member 220 is equivalent to the liquid ejection surface 302a, position detection at intervals corresponding to the width of the head 300 is possible.

As shown in FIG. 18(c), when the detection surface 220a of the second detection member 220 is smaller than the liquid ejection surface 302a, it is possible to perform precise position detection for the drawing target 100. Therefore, it is possible to reduce overlooking obstacles on the drawing target 100 where obstacles such as protrusions are present at narrow intervals.

Next, we will explain how to verify location information.

The liquid ejection device of the present invention has a process for verifying the position information obtained by the position measurement after the position measurement and before performing the ink ejection operation.

In this verification, the carriage 70 is moved relative to the drawing object 100 according to coordinate information indicating the movement trajectory of the carriage 70 obtained based on the position information obtained during position measurement, and it is checked whether any protrusions or the like that were overlooked during position measurement appear. The operation of the carriage 70 during verification is the same as that during ink ejection operation, except that ink ejection is not performed.

Figure 19 shows the overall flow diagram of the liquid ejection device of the present invention.

As described above, the liquid ejection device of the present invention first uses the contact detection unit 200 to detect the position of the carriage 70 relative to the drawing object 100 (step S101).

After detecting (measuring) the position of the carriage 70 relative to the drawing object 100 in the position detection step S101, the movement trajectory of the carriage 70 when ejecting ink onto the drawing object 100 is calculated based on the position information (three-dimensional coordinate information) obtained in the position detection step S101 (step S102).

Next, the carriage 70 is moved along the movement trajectory calculated in step S102, and the movement trajectory is verified (step S103).

During the operation of this verification step S103, it is detected whether there are any obstacles, such as protrusions, on the drawing object 100 that may collide with the carriage 70 and impede the movement of the carriage 70 (step S104).

Then, if no collision with an obstacle is detected in the verification step S103, ink ejection onto the drawing target 100 is enabled (step S105).

Figure 20 shows the flow chart for verifying location information.

First, the carriage 70 equipped with the contact detection unit 200 moves to the drawing start position P1 set by the user on the operation panel 503 (step S1).

Next, the carriage 70 starts moving from the drawing start position P1 under the control of the control unit 500 of the liquid ejection device 1000 (step S2).

Based on the position information detected by the position detection means (push switch 213) during position measurement, the control unit 500 determines three-dimensional (XYZ) coordinates that indicate the movement trajectory of the carriage 70. Then, based on this three-dimensional coordinate information, the control unit 500 moves the carriage 70 toward the drawing end position P2 that the user has set on the operation panel 503.

While the carriage 70 is moving, the contact detection unit 200 attached to the carriage 70 detects protrusions on the drawing object 100 (step S3).

If the contact detection unit 200 does not detect a protrusion while the carriage 70 moves from the drawing start position P1 to the drawing end position P2, the carriage 70 ends its movement (step 4). The details of part A of this flow will be described later.

When the movement of the carriage 70 has finished, the control unit 500 of the liquid ejection device 1000 notifies the user that the verification has been completed by displaying the message on the display unit 502 (step S5).

Then, the carriage 70 moves to the drawing start position P1 (step S6). After moving to the drawing start position P1, the carriage 70 waits to eject ink onto the drawing target 100.

On the other hand, if the contact detection unit 200 detects a protrusion while the carriage 70 is moving from the drawing start position P1 to the drawing end position P2, the control unit 500 of the liquid ejection device 1000 records position information indicating the position of the protrusion (step S7). The recording here is performed, for example, by storing it in the memory unit 501 provided in the liquid ejection device 1000.

Next, the control unit 500 of the liquid ejection device 1000 causes the Z-direction drive unit 92 to move the carriage 70 to the negative side in the Z-axis direction, and the carriage 70 moves to a standby position on the Z-axis (step S8). This causes the carriage 70 to move away from the protrusion.

The control unit 500 of the liquid ejection device 1000 also stops the X-direction drive unit 72 and the Y-direction drive unit 82, and stops the carriage 70 (step S9).

Next, the control unit 500 of the liquid ejection device 1000 displays the position information of the protrusion on the display unit 502 to notify the user (step S10).

Next, the display screen of the operation panel 503 transitions to the position measurement screen (step S11).

In the position measurement screen, the user adds the position information of the protrusion to the position information from the original position measurement if necessary. The user may add the position information of the protrusion manually after checking the state of the drawing target 100 and determining whether or not it is necessary to add the information, or the liquid ejection device 1000 may add the information automatically.

As described above, if the contact detection unit 200 detects a protrusion in step S3, the position information of the protrusion is added to the position information from the original position measurement, and the flow is executed again from step S1. Then, if the contact detection unit 200 does not detect a protrusion while the carriage 70 moves from the drawing start position P1 to the drawing end position P2, the verification is completed, and the process proceeds to the process of actually ejecting ink toward the drawing object 100.

Note that after verification is complete, ink ejection does not necessarily begin. Position measurement may be performed again after the first verification is completed. By repeating position measurement and verification of the object to be drawn 100, more precise three-dimensional coordinate information of the object to be drawn 100 can be obtained, and ink ejection suitable for the shape can be performed.

In addition, the three-dimensional coordinate information created once through position measurement and verification is stored in the memory unit 501 of the liquid ejection device 1000, so that the three-dimensional coordinate information can be used when ejecting ink onto an object 100 of the same shape.

In addition, even if the relative position between the liquid ejection device 1000 and the drawing object 100 changes, the coordinate information regarding the shape of the drawing object 100 is available. Therefore, if the drawing object 100 has the same shape, the user can omit at least part of the verification process by using the position information in the position measurement.

In addition, when detecting a protrusion on the drawing object 100, when the protrusion on the drawing object 100 collides with the second detection member 220 of the contact detection unit 200, the protrusion is detected by the second detection member 220 (details will be described later). However, the detection of the protrusion may not be a configuration that detects physical contact as described above, but may be a configuration that detects optically using laser light or the like, or a configuration that detects by image processing.

The detection target is not limited to protrusions on the drawing object 100. By configuring detection using optical or image processing as described above, it is also possible to detect holes in the drawing object or areas where drawing is intentionally avoided (for example, images that have already been drawn or masked areas).

As described above, this embodiment is a liquid ejection device 1000 that includes a nozzle 302 that ejects ink toward the drawing object 100, and a carriage 70 that can move in at least one direction of the X-axis direction and the Y-axis direction intersecting the X-axis, and in the Z-axis direction intersecting the X-axis and the Y-axis and parallel to the direction in which ink is ejected from the nozzle 302 toward the drawing object 100. The liquid ejection device 1000 includes a push switch 213 that detects the position of the carriage 70 relative to the drawing object 100, and a control unit 500 that controls the movement of the carriage 70. After the push switch 213 detects the position of the carriage 70 relative to the drawing object 100, the control unit 500 calculates the movement trajectory of the carriage 70 when ejecting ink toward the drawing object 100, and performs a verification operation (first operation) of moving the carriage 70 along the calculated movement trajectory before the carriage 70 ejects ink toward the drawing object 100.

This makes it possible to provide a liquid ejection device 1000 that can prevent collision between the drawing object 100 and the carriage 70 during ink ejection.

As described above, if a protrusion is detected on the drawing object 100 during the verification operation, the fact that a protrusion has been detected is displayed on the display unit 502 to notify the user. If a protrusion is not detected on the drawing object 100 during the verification operation, an operation (second operation) of ejecting ink onto the drawing object 100 is enabled.

This makes it possible to recognize protrusions that may have been overlooked during the position detection process.

Figure 21 is an explanatory diagram showing the positional relationship of the carriage during verification and when ink ejection is performed.

When verifying the position information, the carriage 70 is in the position shown by the solid line relative to the drawing target 100. When ejecting ink onto the drawing target 100, the carriage 70 is in a position shifted by a distance L1 in the positive Z-axis direction, as shown by the dashed line.

During verification, the carriage 70 is equipped with the contact detection unit 200, so the distance L1 is set taking into consideration the size of the contact detection unit 200 in the Z-axis direction, etc. Therefore, when ink is ejected onto the drawing target 100, the control unit 500 ejects ink at a position corrected for the distance L1.

In addition, the movement trajectory and movement speed of the carriage 70 when verifying the position information are the same as when ejecting ink onto the drawing object 100.

When the liquid ejection device ejects ink onto an object to be drawn, such as the body of a car or truck or the fuselage of an aircraft, the liquid ejection device becomes a large system. Therefore, the rails and device frame may bend due to the weight of the carriage 70 and the rails 101, 102, and 103 of the X-axis, Y-axis, and Z-axis, or the inertial force caused by the movement of the carriage 70.

Therefore, when verifying the position information, it is desirable to perform operations that correspond to the operations when actually ejecting ink onto the drawing object 100. By making the movement trajectory and movement speed of the carriage when verifying the position information the same as when ejecting ink onto the drawing object, the movement trajectory of the carriage 70 can be accurately verified.

As described above, during the verification operation, the carriage 70 moves at the same speed as during the ink ejection operation.

This improves the accuracy of the carriage 70's operation when ejecting ink.

Figure 22 is an explanatory diagram showing an example of a case where a protrusion is detected during verification. Figure 22(a) shows the state before the protrusion is detected, and Figure 22(b) shows the state after the protrusion is detected.

Let's say there is a protrusion 110 on the surface of the drawing object 100 that was overlooked during position measurement.

In the state shown in FIG. 22(a), the second detection member 220 is attached in the correct position relative to the first detection member 210. Therefore, the detection plates 215a, 215b of the first detection member 210 and the leaf springs 225a, 225b of the second detection member 220 are in contact with each other, and the series connection circuit is in a conductive state.

When the protrusion 110 comes below the carriage 70 as the carriage 70 moves in the positive X-axis direction, the second detection member 220 collides with the protrusion 110 and is unable to move any further in the positive X-axis direction. This causes the detection plates 215a, 215b of the first detection member 210 to separate from the leaf springs 225a, 225b of the second detection member 220, and the series connection circuit becomes non-conductive. After the protrusion is detected, processing is performed based on the flow shown in Figure 20.

Figure 23 is an explanatory diagram showing an example of the electrical connection state of the series connection circuit. Figure 23 (a) shows the state in which the contact detection unit is correctly attached to the carriage, and Figure 23 (b) shows the state in which the second detection member of the contact detection unit is not correctly attached.

When the protrusion shown in FIG. 23(b) is detected, the state shown in FIG. 22(b) will result.

Figure 24 is an explanatory diagram showing an example of the carriage movement trajectory.

The carriage 70, which is positioned at the drawing start position P1, moves in the positive direction of the X axis, and when it reaches the turnaround position, it moves in the positive direction of the Y axis by a movement amount La (line break).

After the line feed, the carriage 70 moves to the negative side in the X-axis direction, and when it reaches the turn-around position, it again starts a line feed in the positive Y-axis direction by the movement amount La. By repeating this operation, the carriage 70 moves along the movement trajectory indicated by the arrow to the drawing end position P2.

If the line feed movement amount of the carriage 70 is fixed at La, the carriage 70 may go outside the drawing area 100a on the last line.

If the carriage 70 is moved outside the drawing area 100a, when the contact detection unit 200 detects a protrusion, it will be unable to distinguish whether the protrusion is detected inside the drawing area 100a or outside the drawing area 100a.

For this reason, it is desirable for the carriage 70 to move from the drawing start position P1 to the drawing end position P2 so as not to go outside the drawing area 100a. Therefore, in this example, the movement amount Lb of the carriage 70 in the last line is made smaller than the movement amount La, and the trajectory of the carriage 70 is controlled so as to coincide with the drawing end position P2.

It is desirable to perform this operation the same when verifying the position information and when ejecting ink onto the drawing object. Note that instead of changing only the movement amount of the final line as described above, the movement amount La and the movement amount Lb may be made equal so that the final line fits within the drawing area 100a.

Figure 25 is a detailed flow diagram of part A of the verification flow in Figure 20.

The number of times and the amount of movement of the carriage 70 are determined while checking the remaining amount of the drawing area 100a in the Y-axis direction so that the carriage 70 does not go outside the drawing area 100a.

The carriage 70, which is positioned at the drawing start position P1 (see FIG. 24), is driven by the X-direction drive unit 72 to move in the positive X-axis direction (step S21).

As the carriage 70 moves in the positive X-axis direction, the counter that counts the number of movements in the X-axis direction increments the count value by 1 (step S22).

When the carriage 70 reaches the end point (turn-around position) on the positive side of the X-axis direction, the control unit 500 determines whether there is any remaining drawing area in the Y-axis direction of the drawing area 100a (step S23).

If there is no more drawing area remaining, this means that the carriage 70 has reached the drawing end position P2, so the X-axis movement count is reset (step S33). Then, the movement of the carriage 70 ends.

On the other hand, if step S23 determines that there is remaining drawing area, it is determined whether the remaining amount is equal to or greater than La (step S24).

Here, the movement amount La corresponds to the length (height) of the carriage 70 (nozzle surface 302a) in the Y-axis direction. Therefore, if there is a remaining amount in the Y-axis direction of the drawing area 100a that is equal to or greater than La, it means that a line break is possible in the Y-axis direction by the height of the carriage 70.

If the remaining amount is equal to or greater than La in step S24, the carriage 70 is driven by the Y-direction drive unit 82 to move by the movement amount La in the positive Y-axis direction (step S25).

Also, in step S24, if the remaining amount is less than La, the carriage 70 is driven by the Y-direction drive unit 82 to move by the movement amount Lb toward the positive side in the Y-axis direction (step S26). As described in FIG. 24, the movement amount Lb is a value smaller than the movement amount La, and is set so that the carriage 70 coincides with the drawing end position P2.

After being moved in the Y-axis direction by step S25 or step S26, the carriage 70 is now moved in the negative X-axis direction by the drive of the X-axis drive unit 72 (step S27).

As the carriage 70 moves in the negative X-axis direction, the counter that counts the number of movements in the X-axis direction increments the count value by 1 (step S28).

When the carriage 70 reaches the end point (turnaround position) on the negative side of the X-axis direction, the control unit 500 determines whether there is any remaining drawing area in the Y-axis direction of the drawing area 100a (step S29).

If there is no more drawing area remaining, this means that the carriage 70 has reached the drawing end position P2, so the X-axis movement count is reset (step S33). Then, the movement of the carriage 70 ends.

On the other hand, if step S29 determines that there is remaining drawing area, it is determined whether the remaining amount is equal to or greater than La (step S30).

If the remaining amount is equal to or greater than La in step S30, the carriage 70 is driven by the Y-direction drive unit 82 to move by the movement amount La in the positive Y-axis direction (step S31).

Also, in step S30, if the remaining amount is less than La, the carriage 70 is driven by the Y-direction drive unit 82 to move by the movement amount Lb toward the positive side in the Y-axis direction (step S32).

After the carriage 70 has moved in the Y-axis direction in step S31 or step S32, the process returns to step S21 and repeats the above flow until there is no more drawing area remaining.

By moving the carriage 70 relative to the drawing area 100a in this manner, the carriage 70 does not extend outside the drawing area 100a, and position measurement, verification, and ink ejection can be performed accurately for the designated drawing area.

Figure 26 is an explanatory diagram showing an example of a display screen of an operation panel of a liquid ejection device.

The user can use the operation panel 503 to input XY coordinate information for identifying the drawing start position P1 and drawing end position P2 of the drawing area (print range) 100a, and to specify the movement speed of the carriage 70. The user can also use the operation panel 503 to specify three-dimensional coordinate information (body data) that indicates the surface shape of the drawing target 100, and to input the distance between the head and the drawing target (set gap), etc.

Figure 27 is an explanatory diagram of the fall prevention member for the second detection member of the contact detection unit.

The first detection member 210 and the second detection member 220 that make up the contact detection unit 200 are attached by the magnetic force of a magnet as described above.

Therefore, if the detection of the protrusion causes the first detection member 210 and the second detection member 220 to move relative to each other by an amount equal to or greater than the area of the magnet, the second detection member 220 may fall from the first detection member 210, which may result in damage to the second detection member 220.

Therefore, in order to prevent the second detection member 220 from falling, the first detection member 210 and the second detection member 220 may be connected with a string-like member 230. The string-like member 230 may be a string, wire, chain, or the like. Note that the string, wire, chain, and the like are examples of a fall prevention member.

Figure 28 is an explanatory diagram of a liquid ejection device according to a modified example of the present invention, and Figure 29 is an enlarged perspective view of the liquid ejection device according to the same modified example.

The liquid ejection device 1000 includes a linear rail 404 along which the carriage 1 moves linearly back and forth, and an articulated robot 405 that moves the linear rail 404 to a desired position and holds it in that position.

The articulated robot 405 is equipped with a robot arm 405a that has multiple joints that allow it to move freely like a human arm, and the tip of the robot arm 405a can be moved freely and positioned accurately.

As the articulated robot 405, for example, a six-axis controlled industrial robot equipped with six axes, i.e., six joints, can be used. With a six-axis articulated robot, by teaching information regarding the operation in advance, the linear rail 404 can be extremely accurately and quickly positioned at a predetermined position on the drawing object 702 (aircraft). The robot 405 is not limited to six axes, and an articulated robot equipped with an appropriate number of axes, such as five axes or seven axes, can be used.

The robot arm 405a of the robot 405 is equipped with a fork-shaped support member 424. A vertical linear rail 423a is attached to the tip of the left branch 424a of this support member 424, and a vertical linear rail 423b is attached to the tip of the right branch 424b so that they are parallel to each other.

The two ends of the linear rail 404 that holds the carriage 1 movably are supported by two vertical linear rails 423a and 423b.

The carriage 1 is equipped with the head 300 described in FIG. 2 etc., or a plurality of heads 300 that eject ink of each color, such as yellow, magenta, cyan, black, and white, or a head 300 having a plurality of nozzle rows. Ink of each color is supplied from an ink tank 330 to each head 300 or each nozzle row of the head 300 of the carriage 1.

This liquid ejection device 1000 uses the robot 405 to move the linear rail 404 to the drawing area of the drawing object 702, and drives the head 300 while moving the carriage 1 along the linear rail 404 according to the drawing data to perform drawing.

Then, when drawing of one line is completed, the vertical linear rails 423a and 423b are driven to move the head 300 of the carriage 1 from one line to the next line.

By repeating this operation, it is possible to draw in the required drawing area of the drawing object 702. Even in the above modified example, the above-mentioned effects of the present invention can be obtained by mounting a contact detection unit on the carriage 1, performing position measurement and verification, and then performing ink ejection.

Next, an application example of the present invention will be described with reference to Figs. 30 to 32. The present invention can also be applied to an unmanned aerial vehicle 6000 such as a drone shown in Fig. 30. The unmanned aerial vehicle 6000 controls the position of the unmanned aerial vehicle 6000 based on the detection results of a detector 610 such as a distance measuring sensor mounted on the unmanned aerial vehicle 6000. The unmanned aerial vehicle 6000 is equipped with a liquid ejection unit 620 including a head that ejects liquid such as ink, and supplies liquid contained in a liquid tank 630 to the liquid ejection unit 620 via a cable 640. Based on the above position control, the unmanned aerial vehicle 6000 ejects liquid from the head provided on the liquid ejection unit 620 toward an object 100 (the wall surface of a building in this embodiment) and applies the liquid to a coating portion P of the object 100.

The present invention can also be applied to an unmanned vehicle 7000 such as a wall climbing robot as shown in FIG. 31. The unmanned vehicle 7000 can move by driving a roller 710 while sucking an object (a wall of a building in this embodiment) 100 at the bottom of the unmanned vehicle 7000. The unmanned vehicle 7000 is equipped with a liquid ejection unit 720 including a head that ejects liquid such as ink, and supplies liquid contained in a liquid tank 730 to the liquid ejection unit 720 via a cable 740. The unmanned vehicle 7000 then ejects liquid from the head provided on the liquid ejection unit 720 toward the object (a wall of a building in this embodiment) 100, and applies the liquid to a coating portion P of the object 100.

Furthermore, the present invention can be applied to a painting robot 8000 shown in FIG. 32, which paints, for example, the body of an automobile. The painting robot 8000 includes a robot arm 810 that can move freely like a human arm by using multiple joints, and a liquid discharge unit 820 including a head that discharges liquid at the tip of the robot arm 810. The robot arm 810 also includes a 3D sensor 830 near the liquid discharge unit 820. A multi-joint robot with an appropriate number of axes, such as 5 axes, 6 axes, or 7 axes, can be used as the painting robot 8000. The painting robot 8000 detects the position of the liquid discharge unit 820 relative to the object (in this embodiment, the vehicle body) 100 by using the 3D sensor 830, and moves the robot arm 810 based on the detection result to paint the object 100.

The above is just one example, and the present invention provides unique effects for each of the following aspects:

[First aspect]
The first aspect is a liquid ejection device 1000 (an example of a liquid ejection device) including a nozzle 302 (an example of a liquid ejection port) that ejects ink (an example of a liquid) toward a drawing target 100 (an example of a target object), and a carriage 70 (an example of a liquid ejection unit) that is movable in at least one direction of an X-axis direction (an example of a first direction) and a Y-axis direction (a second direction intersecting with the first direction) that intersects with the X-axis, and a Z-axis direction (an example of a third direction that intersects with the first direction and the second direction and is parallel to the direction in which liquid is ejected from the liquid ejection port toward the target object) that intersects with the X-axis and Y-axis and is parallel to the direction in which ink is ejected from the nozzle 302 toward the drawing target 100, the liquid ejection device 1000 (an example of a liquid ejection device) including a push switch 213 (an example of a position detection means) that detects the position of the carriage 70 relative to the drawing target 100, and a control unit (an example of a control means) that controls the movement of the carriage 70, the control unit 500 including:
After the push switch 213 detects the position of the carriage 70 relative to the object to be drawn 100, the movement trajectory of the carriage 70 when ejecting ink onto the object to be drawn 100 is calculated, and a verification operation (an example of a first operation) is performed in which the carriage 70 is moved along the calculated movement trajectory before the carriage 70 ejects ink onto the object to be drawn 100.

According to this aspect, it is possible to provide a liquid ejection device 1000 that can prevent collision between the drawing object 100 and the carriage 70 during ink ejection.

[Second aspect]
The second aspect is characterized in that in the first aspect, if a protrusion 110 (an example of an obstacle) is detected on the drawing object 100 during the verification operation, the fact that the protrusion 110 has been detected is displayed on the display unit 502 to notify the user (an example of a notification).

[Third aspect]
The third aspect is characterized in that in the first or second aspect, if no protrusion 110 is detected on the object to be drawn 100 during the verification operation, an operation of ejecting ink onto the object to be drawn 100 (an example of the second operation) is enabled.

According to the second and third aspects, it is possible to recognize protrusions that may have been overlooked during the position detection process.

[Fourth aspect]
A fourth aspect is any one of the first to third aspects, characterized in that, in the verification operation, the carriage 70 moves at the same speed as in the ink ejection operation.

According to the fourth aspect, it is possible to improve the accuracy of the operation of the carriage 70 when ejecting ink.

[Fifth aspect]
The fifth aspect is characterized in that, in any of the first to fourth aspects, a push switch 213 and detection plates 215a, 215b (an example of an obstacle detection means) for detecting the protrusion 110 are removably provided on the carriage 70.

According to the fifth aspect, the push switch 213 and the detection plates 215a, 215b can be removed from the carriage 70 when they are not needed, thereby preventing accidental damage to the push switch 213 and the detection plates 215a, 215b.

[Sixth aspect]
The sixth aspect is characterized in that in any one of the first to fifth aspects, the push switch 213 and the detection plates 215a, 215b are integrally provided as a contact detection unit 200 (an example of a contact detection unit).

According to the sixth aspect, the push switch 213 and the detection plates 215a and 215b can be easily attached to and detached from the carriage 70. In addition, different types of detection can be achieved with a single contact detection unit 200.

70 Carriage (an example of a liquid ejection unit)
72 X-direction driving section 82 Y-direction driving section 92 Z-direction driving section 100 Drawing object (an example of a target object)
101 X-axis rail 102 Y-axis rail 103 Z-axis rail 200 Contact detection unit 210 First detection member (an example of a first member)
213 Push switch (an example of a position detection means)
214 Magnet 215a, 215b Detection plate (an example of an obstacle detection means)
220 Second detection member (an example of the second member)
220a: detection surface; 224: magnet; 225a, 225b: leaf spring; 230: string-shaped member (an example of a fall prevention member)
300 Head 302 Nozzle (an example of a liquid ejection port)
302a: Nozzle surface (an example of a liquid ejection surface)
500 Control unit (an example of a control means)
1000 Liquid discharge device

JP 2018-001715 A

Claims (12)

A liquid ejection device including a liquid ejection port that ejects liquid toward a target object, and a liquid ejection unit that is movable in at least one of a first direction and a second direction intersecting the first direction, and in a third direction intersecting the first direction and the second direction and parallel to a direction in which the liquid is ejected from the liquid ejection port toward the target object,
a contact detection unit having a position detection unit that detects a position of the liquid discharge unit with respect to the target object, and a control unit that controls a movement of the liquid discharge unit;
the liquid discharge unit is movable between a discharge position where the liquid is discharged toward the target and a standby position that is farther away from the target in the third direction than the discharge position;
the contact detection unit is attached to the liquid ejection unit in a standby position so as to cover the liquid ejection port;
The control means
A liquid ejection device characterized in that, after the position detection means detects the position of the liquid ejection unit relative to the target object, a movement trajectory along which the liquid ejection unit ejects liquid onto the target object is calculated, and before the liquid ejection unit ejects liquid onto the target object, a first operation is performed to move the liquid ejection unit along the calculated movement trajectory. the contact detection unit includes a first member attached to the liquid ejection unit and a second member attached to the first member so as to be movable relative to the first member;
The liquid ejection device according to claim 1 , wherein a collision with the object in the first direction is detected based on the relative movement. 3. The liquid ejection apparatus according to claim 1, wherein the position detection means includes a detection means for detecting contact in the third direction. the position detection means detects a position of the liquid ejection unit relative to the object by the contact detection unit coming into contact with the object in the third direction;
4. The liquid ejection apparatus according to claim 1, wherein the control unit calculates the movement trajectory based on a result of the detection. 5. The liquid ejection device according to claim 1, wherein, when an obstacle is detected on the target object during the first operation, the detection of the obstacle is notified. A liquid ejection device according to any one of claims 1 to 5, characterized in that if no obstacle is detected on the object during the first operation, a second operation of ejecting liquid onto the object is enabled. The liquid ejection apparatus according to claim 6 , wherein in the first operation, the liquid ejection unit moves at the same speed as in the second operation. 7. The liquid ejection apparatus according to claim 5, wherein the position detection means and the obstacle detection means for detecting the obstacle are detachably provided on the liquid ejection unit. an obstacle detection means for detecting the obstacle,
8. The liquid ejection device according to claim 5, wherein the position detection means and the obstacle detection means are integrally provided. A liquid ejection method for a liquid ejection device including a liquid ejection unit that is provided with a liquid ejection port that ejects liquid toward a target, and that is movable in at least one of a first direction and a second direction intersecting the first direction, and a third direction intersecting the first direction and the second direction and parallel to a direction in which the liquid is ejected from the liquid ejection port toward the target, and that is movable between an ejection position where the liquid is ejected toward the target and a standby position that is farther away from the target in the third direction than the ejection position,
a position detection step in which a position detection means of a contact detection unit attached to the liquid discharge unit in the standby position so as to cover the liquid discharge port detects a position of the liquid discharge unit with respect to the target object;
a movement trajectory calculation step of calculating a movement trajectory of the liquid discharge unit when discharging liquid onto the target object after detecting a position of the liquid discharge unit with respect to the target object in the position detection step;
a first step of moving the liquid ejection unit along the calculated movement trajectory before the liquid ejection unit ejects liquid onto the target;
A liquid ejection method comprising the steps of: The liquid ejection method according to claim 10, further comprising the step of: enabling a second step of ejecting liquid onto the object if no obstacle is detected on the object during the first step. A liquid ejection device including a liquid ejection port that ejects liquid toward a target object, and a liquid ejection unit that is movable in at least one of a first direction and a second direction intersecting the first direction, and in a third direction intersecting the first direction and the second direction and parallel to a direction in which the liquid is ejected from the liquid ejection port toward the target object,
a contact detection unit having a position detection means for detecting a position of the liquid discharge unit with respect to the target object, and a control means for moving the liquid discharge unit along a predetermined movement trajectory based on input information,
the liquid discharge unit is movable between a discharge position where the liquid is discharged toward the target and a standby position that is farther away from the target in the third direction than the discharge position;
the contact detection unit is attached to the liquid ejection unit in a standby position so as to cover the liquid ejection port;
A liquid ejection device characterized in that the control means performs a first operation to move the liquid ejection unit along the predetermined movement trajectory before the liquid ejection unit ejects liquid along the predetermined movement trajectory onto the target object.