JP7660790B2 - LIQUID DISCHARGE UNIT AND LIQUID DISCHARGE APPARATUS - Google Patents

Description

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

Patent Document 1 discloses a cleaning device for an ink ejection section, which includes a first blade member for scraping off ink from the surface of the ink ejection section, a cleaning liquid roller for cleaning the surface of the ink ejection section with a water-soluble organic solvent, a water roller for cleaning the surface of the ink ejection section that has been cleaned with the water-soluble organic solvent with water, a second blade member for scraping off liquid from the surface of the ink ejection section that has been cleaned with the water roller, and a casing that supports the first blade member, the cleaning liquid roller, the water roller, and the second blade member, the casing being movable along the longitudinal direction of the surface of the ink ejection section, and the first blade member, the cleaning liquid roller, the water roller, and the second blade member being arranged to come into contact with the surface of the ink ejection section in this order as the casing moves.

The object of the present invention is to provide a liquid ejection unit capable of supplying a cleaning agent to a liquid ejection surface that is arranged to face a surface that intersects with a horizontal plane.

The present invention is a liquid ejection unit that ejects liquid toward an object having a surface that intersects with a horizontal plane, the liquid ejection unit having a liquid ejection surface that can face the surface that intersects with the horizontal plane, a cleaning device that cleans the liquid ejection surface, and a driving means that moves the cleaning device relatively to the liquid ejection surface, the cleaning device having a contact member that is arranged to be in contact with the liquid ejection surface, a detergent supplying device that supplies detergent from the surface side of the contact member, and a liquid droplet receiving portion for receiving the liquid ejected from a liquid ejection port provided on the liquid ejection surface , and the detergent supplying device supplies the detergent to the liquid droplet receiving portion .

The present invention provides a liquid ejection unit capable of supplying a cleaning agent to a liquid ejection surface that is arranged to face a surface that intersects with a horizontal plane.

1 is an overall perspective view of a liquid ejection device according to an embodiment of the present invention. FIG. FIG. 4 is an overall perspective view of the carriage (at a liquid ejection position). FIG. FIG. FIG. 4 is an explanatory diagram of supply of a detergent to a detergent supply roller. FIG. 4 is a block diagram of a portion relating to cleaning control. FIG. 4 is a flow diagram showing an example of a printing process. FIG. 4 is a flow diagram showing an example of a cleaning process. FIG. 4 is a flow chart showing an example of a foreign matter removing process. FIG. 4 is a flow diagram showing an example of a blank discharge process. FIG. 4 is an explanatory diagram of the positional relationship of each member in a printing process. FIG. 4 is an explanatory diagram of the positional relationship of each member in a cleaning process. FIG. FIG.

The following describes an embodiment of the present invention with reference to the drawings.

Figure 1 is an overall perspective view of a printing device shown as an example of a liquid ejection device of the present invention.

The printing device 1000 is installed facing the drawing object 100, which is an example of an object. The printing device 1000 has 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 direction (positive and negative). The X-axis rail 101 also holds the Z-axis rail 103 so that the Z-axis rail 103 can move in the X direction (positive and negative). The Z-axis rail 103 then holds the carriage 1 so that the carriage 1 can move in the Z direction (positive and negative). Here, the carriage 1 is an example of a liquid ejection unit.

The printing device 1000 includes a first Z-direction drive unit 92 that moves the carriage 1 in the Z direction along the Z-axis rail 103, and an X-direction drive unit 72 that moves the Z-axis rail 103 in the X direction along the X-axis rail 101. The printing device 1000 also includes a Y-direction drive unit 82 that moves the X-axis rail 101 in the Y direction along the Y-axis rail 102. The printing device 1000 also includes a second Z-direction drive unit 93 that moves the head holder 70 in the Z direction relative to the carriage 1. Here, the head holder 70 is an example of a holder.

The printing device 1000 configured as described above ejects ink, an example of a liquid, from a head provided on the head holder 70 while moving the carriage 1 in the X, Y, and Z directions, and performs drawing on the drawing target 100. Note that the movement of the carriage 1 and head holder 70 in the Z direction does not necessarily mean that it is parallel to the Z direction, and it may be an oblique movement as long as it includes at least a component in the Z direction.

In FIG. 1, the surface shape of the drawing object 100 is a flat surface, but the surface shape of the drawing object 100 may be a nearly vertical surface, such as the body of a car or truck, or the body of an airplane, a surface with a large radius of curvature, or a surface with some unevenness. In other words, any drawing object that has a surface that intersects with the horizontal plane (X-Z plane) is eligible.

When printing on items that will ultimately be exposed to the outside air, such as signs, exterior walls of buildings, and vehicle bodies and aircraft bodies, the printing surface needs to be quick-drying and strong. For this reason, the ink used for printing is either a mixture of pigments in a volatile solvent such as thinner or acetone, or a highly viscous ink.

Next, the configuration of carriage 1 will be explained.

Figure 2 is an overall perspective view of the carriage in an example printing device, showing the carriage in a standby position on the Z axis.

The carriage 1, which is an example of a liquid ejection unit, is equipped with a head holder 70, which is an example of a holder. The carriage 1 can move in the Z direction along the Z-axis rail 103 by power from a first Z-direction drive unit 92. In addition, the head holder 70 can move in the Z direction relative to the carriage 1 by power from a second Z-direction drive unit 93 shown in FIG. 1.

The head holder 70 holds a head, which is an example of a liquid ejection body, and here, six heads 300a to 300f are arranged in a stacked manner on the head holder 70. In the following description, these heads will be referred to collectively as head 300.

Each of the heads 300a to 300f has a liquid ejection surface (nozzle surface) 302a having a plurality of liquid ejection ports (nozzles) 302. The type and number of ink colors used by the heads 300a to 300f may be different for each head, or may all be the same color. For example, if the liquid ejection device exemplified as the printing device 1000 is a coating device that uses a single color, the inks used by the heads 300a to 300f may be the same color. Furthermore, the number of heads constituting the head 300 is not limited to six. It may be more than six, or it may be less than six.

As shown in the figure, the heads 300 are fixed to the head holder 70 so that the nozzle surface 302a of each head intersects with the horizontal plane (X-Z plane) and the arrangement direction of the multiple nozzles 302 is inclined with respect to the X-axis. This causes the nozzles 302 to eject ink in a direction that intersects with the direction of gravity (Z direction).

The carriage 1 also includes a cleaning device 4 that cleans the head 300. The carriage 1 supports a frame 2 that is arranged to surround the periphery of the head holder 70. The frame 2 includes a shaft member 3 that extends in the X direction, and the cleaning device 4 is attached to the shaft member 3 so that it can move along the shaft member 3.

Although not shown, the frame 2 includes a drive motor for moving the cleaning device 4 along the shaft member 3, a position sensor for detecting the position of the cleaning device 4 in the X direction (standby position, folded-back position), and the like. As a result, the drive motor transmits power to the power transmission belt 5, and the cleaning device 4 connected to the power transmission belt 5 moves in the positive X direction along the shaft member 3.

The cleaning device 4 then cleans the nozzle surface 302a and nozzles 302 of the head 300. When the cleaning device 4 moves further in the positive X direction and reaches the turning position, the movement direction of the cleaning device 4 switches to the negative X direction, and the cleaning device 4 returns to the standby position. Here, the drive motor, shaft member 3, power transmission belt 5, etc. are an example of a drive means that moves the cleaning device 4 relative to the nozzle surface 302a.

Figure 3 is an overall perspective view of the carriage in an example printing device, showing the carriage and head in the ink ejection position on the Z axis.

The difference from Figure 2 is that the carriage 1 and head holder 70 have been moved toward the drawing object 100 (positive side in the Z direction). Like the carriage 1, the head holder 70 also moves in the Z direction between the ink ejection position (Figure 3) and the standby position (Figure 2). Note that the Z direction position of the carriage 1 when ejecting ink is not always constant. The Z direction position of the carriage 1 when ejecting ink varies in accordance with the surface shape of the drawing object 100.

Figure 4 is an explanatory diagram showing the configuration of the cleaning device, and shows the back side of the cleaning device 4 shown in Figures 2 and 3.

As mentioned above, in the case of ink in which a volatile solvent such as thinner or acetone is mixed into a highly viscous ink solvent, the heat of vaporization generated when the volatile components of the thinner or acetone evaporate causes the ink solvent to solidify. In addition, components such as thinner and acetone evaporate quickly, and evaporate immediately after the ink is ejected, so the ink solvent is likely to solidify on the nozzle 302 and nozzle surface 302a. Furthermore, because the ink is highly viscous, once the ink has solidified, it cannot be completely removed by simply rubbing it with a cleaning member such as a blade.

The present invention therefore provides the cleaning device 4 with a cleaning agent supply 41, a cleaning agent supply roller 42, a cleaning blade 43 and an empty discharge receiving surface 44, making it possible to remove ink that has adhered to the nozzle 302 and the nozzle surface 302a.

When the carriage 1 is in a standby position on the Z axis (see FIG. 2), the cleaning device 4 moves back and forth between the positive side in the X direction and the negative side in the X direction relative to the nozzle surface 302a of the head 300.

The detergent supply device 41 has a detergent supply pipe 411 arranged along the axial direction of the detergent supply roller 42. The detergent supply pipe 411 has multiple detergent supply ports 412 along the axial direction of the detergent supply roller 42, and supplies an organic solvent, which is an example of a detergent, to each supply port described below. The first detergent supply port 412 is located close to the outer circumferential surface of the detergent supply roller 42, and sprays the organic solvent toward the outer circumferential surface of the detergent supply roller 42. Here, the detergent supply device 41 is an example of a detergent supply device.

At least the outer layer of the cleaning agent supply roller 42 is made of a sponge or the like that is highly absorbent to organic solvents, and the cleaning agent supply roller 42 is configured so that the organic solvent can easily soak into it. When the cleaning agent supply roller 42 containing the organic solvent comes into contact with the nozzle surface 302a of the head 300, the organic solvent dissolves the residual ink that has adhered to the nozzle surface 302.

The cleaning agent supply roller 42 also rotates in the direction of arrow A (counterclockwise) during cleaning. Therefore, when the cleaning device 4 is moved in the positive X direction relative to the nozzle surface 302a, the cleaning agent supply roller 42 comes into contact with the nozzle surface 302a while moving in the opposite direction to the movement of the cleaning device 4 (negative X direction). This makes it possible to continuously supply organic solvent to the residual ink on the nozzle surface 302a, allowing the residual ink to be dissolved more effectively.

Here, the detergent supply roller 42 is an example of a contact member. Note that the embodiment of the contact member is not limited to a roller. For example, the contact member may be in the form of an endless belt supported by multiple shafts. Note that the detergent may be supplied from the detergent supply device 41 to the detergent supply roller 42 by dripping it from above the detergent supply roller 42.

As described above, the cleaning agent supplying device 41 sprays the cleaning agent onto the cleaning agent supplying roller 42. This allows the cleaning agent to be supplied directly to the outer peripheral surface of the cleaning agent supplying roller 42, and the nozzle surface 302a can be efficiently cleaned using a small amount of cleaning agent.

The cleaning blade 43 comes into contact with the nozzle surface 302a and scrapes off foreign matter such as residual ink that has adhered to the nozzle surface 302a. That is, the cleaning blade 43 is provided at a position on the negative side of the cleaning agent supply roller 42 in the X direction, and the cleaning blade 43 scrapes off foreign matter whose adhesion has been reduced by the organic solvent.

Here, the cleaning blade 43 is an example of an abutting member. Note that the embodiment of the abutting member is not limited to the single blade configuration as described above. For example, it may be configured with multiple blades.

The idling receiving surface 44 is a member that faces the nozzle surface 302a when performing idling ink ejection in the head 300, and receives the ink droplets ejected by the nozzles 302. The idling receiving surface 44 is provided at a position on the positive side of the X direction relative to the cleaning agent supply roller 42, and is used for the idling ejection process that is performed when the cleaning device 4 moves to the negative side of the X direction (returning path).

A second cleaning agent supply port 413 is provided on the upper part of the dummy discharge receiving surface 44. The second cleaning agent supply port 413 is connected to the cleaning agent supply pipe 411 of the cleaning agent supplier 41, and the ink droplets received by the dummy discharge receiving surface 44 are washed away by the organic solvent supplied from the second cleaning agent supply port 413. Here, the dummy discharge receiving surface 44 is an example of a droplet receiving portion.

As described above, this embodiment is a carriage 1 that ejects ink toward a drawing object 100 having a surface that intersects with a horizontal plane (X-Z plane), and has a nozzle surface 302a that can face the surface that intersects with the horizontal plane, a cleaning device 4 that cleans the nozzle surface 302a, and a driving means (shaft member 3, power transmission belt 5, etc.) that moves the cleaning device 4 relative to the nozzle surface 302a, and the cleaning device 4 has a cleaning agent supply roller 42 that is arranged so as to be in contact with the nozzle surface 302a, and a cleaning agent supply device 41 that supplies cleaning agent (organic solvent) from the surface side of the cleaning agent supply roller 42.

This makes it possible to provide a carriage 1 that can evenly supply cleaning agent to the nozzle surface 302a, which is arranged to face a surface that intersects with the horizontal plane (X-Z plane).

As described above, the cleaning device 4 also has a cleaning blade 43 that comes into contact with the nozzle surface 302a after the cleaning agent has been supplied, and removes foreign matter such as residual ink from the nozzle surface 302a.

This allows foreign matter whose adhesion to the nozzle surface 302a has decreased due to the organic solvent supplied by the cleaning agent supply roller 42 to be reliably removed from the nozzle surface 302a.

As described above, the cleaning device 4 also has a blank discharge receiving surface 44 for receiving ink discharged from the nozzles 302 provided on the nozzle surface 302a.

This allows the empty discharge receiving surface 44 to collect foreign matter inside the nozzle 302 and refresh the nozzle 302.

Also, as described above, the cleaning agent supplying device 41 supplies cleaning agent to the empty discharge receiving surface 44.

This makes it possible to wash away the ink droplets received by the blank ejection receiving surface 44, and prevents the accumulation of ink droplets on the blank ejection receiving surface 44.

Figure 5 is an explanatory diagram of the configuration of the cleaning agent dispenser, where Figure 5(a) is a schematic diagram of the main parts of the cleaning agent dispenser, and Figure 5(b) is a plan view showing an example of the first shutter.

The cleaning agent supply device 41 mainly comprises a cleaning agent supply pipe 411, a first cleaning agent supply port 412, and a second cleaning agent supply port 413. The cleaning agent is taken in from the upper part of the cleaning agent supply pipe 411, and a first shutter 414 and a second shutter 415 are provided on the cleaning agent supply path to each of the cleaning agent supply ports 412 and 413.

The first shutter 414 opens when cleaning agent is supplied to the cleaning agent supply roller 42 and closes when cleaning agent is not supplied to the cleaning agent supply roller 42. The second shutter 415 opens when cleaning agent is supplied to the empty discharge receiving surface 44 and closes when cleaning agent is not supplied to the empty discharge receiving surface 44.

The first shutter 414 may have a variable opening diameter as shown in FIG. 5(b). That is, (i) in FIG. 5(b) is the state in which the first shutter 414 is closed, and the opening diameter of the first shutter 414 is controlled according to the ink ejection amount, the time during which ink is not ejected, the type of ink, and the environmental temperature and humidity. In (ii) in FIG. 5(b), the amount of cleaning agent supplied is small, and in (iii) in FIG. 5(b), the amount of cleaning agent supplied is large. Here, the first shutter 414 is an example of a shutter member.

As described above, the cleaning agent supply device 41 has a first shutter 414 on the supply path of the cleaning agent supply pipe 411, which changes the opening diameter (opening area) of the supply path.

This allows the nozzle surface 302a to be cleaned efficiently using a minimum amount of cleaning agent.

When the detergent supply roller 42 is vertically oriented as in this embodiment, i.e. when the roller rotation axis has a Y-direction (vertical) component, the detergent that has soaked into the detergent supply roller 42 flows in the direction of gravity. As a result, the upper axial side of the detergent supply roller 42 tends to dry out, making it difficult to achieve a state in which the detergent is uniformly soaked in the axial direction of the detergent supply roller 42.

Therefore, the opening diameter of the cleaning agent supply port 412 is changed for each cleaning agent supply port to provide a difference in the amount of cleaning agent supplied. Specifically, a removable cap member 416 is provided for the first cleaning agent supply port 412. There are multiple types of cap members 416 with different opening diameters.

Then, a cap member 416 is attached in advance to the first cleaning agent supply port 412 so that the amount of cleaning agent supplied decreases from the upper cleaning agent supply port to the lower cleaning agent supply port.

Figure 6 is an explanatory diagram of the supply of cleaning agent to the cleaning agent supply roller.

The opening diameter of the first detergent supply port 412 is adjusted by the cap member 416 so that the amount of detergent supplied from the first detergent supply port 412 decreases from the upper detergent supply port to the lower detergent supply port. By providing such a cap member 416, it is possible to improve the uneven distribution of detergent in the axial direction of the detergent supply roller 42, and the detergent can be supplied evenly and sufficiently to the detergent supply roller 42.

The configuration for decreasing the amount of detergent supplied from the upper detergent supply port to the lower detergent supply port is not limited to the above. For example, the detergent supply roller may be installed with its axis tilted 30 degrees, preferably 45 degrees or more, relative to the detergent supply device 41. This makes it possible to vary the distance to the detergent supply roller from the upper detergent supply port to the lower detergent supply port, and to provide a difference in the amount of detergent supplied. Also, installing the detergent supply roller at an angle is more effective as it prevents the detergent supply roller from being continuously immersed in detergent.

As described above, the detergent supply device 41 has multiple detergent supply ports 412 in the direction of a surface that intersects with the horizontal plane (X-Z surface), and the amount of detergent supplied decreases from the upper detergent supply port to the lower detergent supply port.

This allows the cleaning agent to be evenly supplied to the vertically-mounted cleaning agent supply roller 42.

Figure 7 is a block diagram of the parts related to cleaning control.

The printing device 1000 includes an X-direction drive unit 72, a Y-direction drive unit 82, a first Z-direction drive unit 92, a second Z-direction drive unit 93, a cleaning device drive unit 94, a cleaning agent supply roller drive unit 95, a shutter drive unit 96, and a cleaning agent supply unit 97.

The printing device 1000 also has a control unit 500, which includes a cleaning execution determination unit 504, a cleaning agent supply amount calculation unit 505, and a consumables status determination unit 506. The control unit 500 is also connected to a memory unit 501, a display unit 502, an operation panel 503, and the like.

The X-direction drive unit 72 drives the carriage 1 in the X direction (positive and negative sides) based on instructions from the control unit 500. The Y-direction drive unit 82 drives the carriage 1 in the Y direction (positive and negative sides) based on instructions from the control unit 500.

The first Z-direction drive unit 92 drives the carriage 1 in the Z direction (positive and negative) based on instructions from the control unit 500. The second Z-direction drive unit 93 drives the head holder 70 in the Z direction (positive and negative) relative to the carriage 1 based on instructions from the control unit 500.

The cleaning device drive unit 94 drives the cleaning device 4 in the X direction (positive and negative) and Z direction (positive and negative) relative to the head 300 based on instructions from the control unit 500. The cleaning agent supply roller drive unit 95 drives and rotates the cleaning agent supply roller 42 based on instructions from the control unit 500.

The shutter drive unit 96 adjusts the opening diameter and opens and closes the first shutter 414 provided in the cleaning agent supply device 41, and opens and closes the second shutter 415 based on instructions from the control unit 500. The cleaning agent supply unit 97 starts and stops the supply of cleaning agent to the cleaning agent supply device 41.

The control unit 500 includes a CPU that is responsible for the overall control of the printing device 1000, a ROM that stores programs for executing control of the CPU for drawing operations and other fixed data, and other components. The control unit 500 includes a RAM that temporarily stores drawing data to be drawn on the drawing target 100, an I/F for sending and receiving data and signals used when receiving drawing data from a host such as a PC, and other components.

The control unit 500 stores (records) and reads information such as the amount of ink ejected from the nozzles 302 of the head 300, the time when ink is not ejected from the nozzles 302, the type of ink, and information regarding the environmental temperature and humidity in the memory unit 501.

The control unit 500 controls the X-direction drive unit 72, the Y-direction drive unit 82, the first Z-direction drive unit 92, and the second Z-direction drive unit 93 to move the carriage 1 and the head holder 70 along the surface shape of the drawing target 100. The control unit 500 also controls the ejection of ink from the head 300 provided on the head holder 70.

If an abnormality occurs in the carriage 1, the head holder 70, or the head 300, the control unit 500 notifies the user by displaying the abnormality on the display unit 502. The control unit 500 also receives instructions from the operation panel 503 and executes processing corresponding to the instructions.

The control unit 500 includes a cleaning execution determination unit 504, a cleaning agent supply amount calculation unit 505, and a consumables status determination unit 506. The control unit 500 receives instructions from the cleaning execution determination unit 504 and drives the cleaning device drive unit 94 and the cleaning agent supply roller drive unit 95.

The control unit 500 also receives instructions from the cleaning agent supply amount calculation unit 505 and drives the shutter drive unit 96 and cleaning agent supply unit 97. Furthermore, the control unit 500 receives instructions from the consumables status determination unit 506 and displays on the display unit 502 the consumption status of ink and cleaning agent, information regarding the replacement timing of the cleaning agent supply roller 42 and cleaning blade 43, etc.

The memory unit 501 stores information regarding the amount of ink ejected, the time when ink is not ejected, the type of ink, and the environmental temperature and humidity, as well as coordinate information (three-dimensional (XYZ) coordinate information) indicating the surface shape of the object 100 to be drawn.

When an abnormality occurs in the printing device 1000, the display unit 502 displays the details to notify the user. The operation panel 503 makes it possible to input values (coordinates) for specifying the drawing area for the drawing target 100, the moving speed of the carriage 1, and the distance between the head 300 and the drawing target 100. The operation panel 503 can also specify coordinate information to be used for drawing. The display unit 502 and operation panel 503 may be operated on a single screen using a touch panel or the like.

The cleaning execution determination unit 504 determines whether cleaning of the head 300 is necessary based on information on the movement distance of the carriage 1. Note that information on the movement distance of the carriage 1 can be obtained, for example, from the amount of rotation of the drive motor of the X-direction drive unit 72.

The detergent supply amount calculation unit 505 calculates the amount of detergent supply based on the ink ejection amount, the time when ink is not ejected, the type of ink, and information on the environmental temperature and humidity stored in the memory unit 501. Based on the calculation results from the detergent supply amount calculation unit 505, the control unit 500 drives the shutter drive unit 96 and the detergent supply unit 97.

The consumables status determination unit 506 transmits information regarding the timing of replacement of various consumables based on the consumption status of ink and detergent, and the wear status of the detergent supply roller 42 and cleaning blade 43 to the control unit 500.

Figure 8 is a flow diagram showing an example of the drawing process of a printing device according to the present invention.

In the case of the printing device 1000 shown in FIG. 1, the carriage 1, which is located at the drawing start position, is moved in the positive X direction, and one scan of drawing (printing) is performed on the drawing object 100 by this movement in the positive X direction (outward path) (step S1).

If the surface shape of the drawing object 100 is not flat, the carriage 1 moves in the Z direction based on the three-dimensional coordinate information indicating the surface shape of the drawing object 100 in addition to moving in the positive X direction, and performs drawing by following the surface shape of the drawing object 100.

When one scan of drawing on the outward path is completed, the head holder 70 moves from the liquid ejection position shown in Figure 3 to the standby position shown in Figure 2.

The period during which the head holder 70 is in the standby position is also a cleaning period, during which the cleaning device 4 is driven to clean the head 300 (step S2).

Cleaning of the head 300 by the cleaning device 4 is completed before the carriage 1 starts moving in the negative X direction to start drawing. In the cleaning process of step S2, the cleaning device 4 moves over the nozzle surface 302a of the head 300, and removes foreign matter such as residual ink that has adhered to the nozzle surface 302a and performs blank ejection.

When the carriage 1 moves in the positive X direction and reaches the turn-around position, the carriage 1 moves one scan in the negative Y direction (line feed). After the line feed, the carriage 1 starts moving in the negative X direction, and by this movement in the negative X direction (return path), a new scan of drawing is performed on the drawing target 100 (step S3).

When drawing for one scan on the return path is completed, the head holder 70 moves from the liquid ejection position to the standby position, as in step S2, and drives the cleaning device 4 during the cleaning possible period to clean the head 300 (step S4). Cleaning of the head 300 by the cleaning device 4 is completed before the carriage 1 starts moving in the positive X direction.

The control unit 500 of the printing device 1000 repeats steps S1 to S4 until drawing is completed, and the drawing process ends when the control unit 500 determines that drawing is completed (step S5).

Figure 9 is a flow diagram showing an example of a cleaning process, and provides details of the cleaning process performed in steps S2 and S4 of Figure 8.

When the printing device 1000 has completed drawing for one scan on the outward path, the head holder 70 moves from the liquid ejection position shown in FIG. 3 to the standby position shown in FIG. 2. While the head holder 70 is in the standby position (cleanable period), the cleaning device 4 cleans the head 300.

In the cleaning process, first, it is determined whether cleaning of the head 300 is necessary (step S11). This determination is made by the cleaning execution determination unit 504, which determines whether cleaning is necessary based on information such as the movement distance of the carriage 1. If cleaning is not necessary (No), the process ends without cleaning. If cleaning is necessary (Yes), the amount of cleaning agent (organic solvent) required for cleaning is calculated (step S12).

The amount of detergent supply is calculated by the detergent supply amount calculation unit 505. The detergent supply amount calculation unit 505 calculates the amount of detergent supply based on the ink ejection amount, the time when ink is not ejected, the type of ink, and information on the environmental temperature and humidity stored in the memory unit 501. Based on the calculation result, the control unit 500 drives the shutter drive unit 96 and the detergent supply unit 97.

Once the amount of detergent supply has been calculated, the cleaning device 4 starts moving in the positive X-direction (forward path) relative to the nozzle surface 302a (step S13). While the cleaning device 4 is moving in the positive X-direction, foreign matter is removed by the cleaning device 4's detergent supply roller 42 and cleaning blade 43 (step S14).

When the cleaning agent supply roller 42 and cleaning blade 43 pass over the nozzle surface 302a and reach the turning position, the cleaning device 4 starts moving in the negative X-direction (returning direction) (step S15).

While the cleaning device 4 is moving in the negative X-direction, the nozzle 302 performs an empty discharge toward the empty discharge receiving surface 44 of the cleaning device 4 (step S16). This completes the cleaning process.

Figure 10 is a flow diagram showing an example of a foreign matter removal process, and shows details of the foreign matter removal process carried out in step S14 of Figure 9.

When the foreign matter removal process begins, the cleaning agent supply roller 42 starts rotating (step S21). At the same time, the first shutter 414 of the cleaning agent supply device 41 opens, and the organic solvent starts to be sprayed from the first cleaning agent supply port 412 (step S22). This causes the cleaning agent supply roller 42 to hold the organic solvent.

In this state, the cleaning device 4 is moved in the positive X-direction (forward path) relative to the nozzle surface 302a, and foreign matter is removed by the cleaning agent supply roller 42 and cleaning blade 43 (step S23). When the cleaning agent supply roller 42 and cleaning blade 43 pass over the nozzle surface 302a and reach the turning position, the rotation of the cleaning agent supply roller 42 is stopped (step S24).

The first shutter 414 of the cleaning agent supply device 41 is closed, and the spraying of the organic solvent from the first cleaning agent supply port 412 stops (step S25). Next, an increment process is performed on the count value of the number of cleanings performed (step S26).

Next, based on the information such as the number of cleaning operations performed, it is determined whether consumables such as the cleaning agent supply roller 42 and cleaning blade need to be replaced (step S27). This determination is made by the consumables status determination unit 506.

If the consumables status determination unit 506 determines that the consumables do not need to be replaced (No), the foreign matter removal process ends. If the consumables status determination unit 506 determines that the consumables need to be replaced (Yes), the consumables status determination unit 506 displays an alert on the display unit 502 via the control unit 500 (step S28). This notifies the user that it is time to replace the consumables.

In the present embodiment, the cleaning agent supply roller 42 and cleaning blade 43 are not used in the idle discharge process that follows the foreign matter removal process. Therefore, in step S28, an alert is simply displayed, allowing the series of cleaning processes to continue. The foreign matter removal process ends with the above steps.

Figure 11 is a flow diagram showing an example of the blank discharge process, and shows the details of the blank discharge process carried out in step S16 of Figure 9.

When the dummy discharge process begins, the second shutter 415 of the cleaning agent supply device 41 opens, and the supply of organic solvent from the second cleaning agent supply port 413 begins (step S31). This causes the organic solvent to flow from the top to the bottom of the dummy discharge receiving surface 44.

In this state, the cleaning device 4 is moved in the negative X-direction (returning path) relative to the nozzle surface 302a, and ink is sequentially discharged from the nozzles 302 facing the blank discharge receiving surface 44 (step S32). As a result, foreign matter that has become clogged in the nozzles 302 adheres to the blank discharge receiving surface 44. This operation is repeated until the cleaning device 4 reaches the end point of the return path (step S33).

When the blank discharge receiving surface 44 passes over the nozzle surface 302a, ink discharge is stopped (step S34), the second shutter 415 of the cleaning agent supply device 41 is closed, and the supply of cleaning agent from the second cleaning agent supply port 413 is stopped (step S35). With these steps, the blank discharge process is completed.

Figure 12 is an explanatory diagram of the relative positions of each component during the printing process.

When drawing (printing) on the drawing target 100, the Z-axis rail 103 carrying the carriage 1 moves in the positive X-direction along the X-axis rail 101. The head 300 ejects ink toward the drawing target 100 while moving in the positive X-direction, printing one scan's worth of image on the drawing target 100. During the printable period shown in the figure, the head holder 70 holding the head 300 is in a position (liquid ejection position) that protrudes in the positive Z-direction (towards the drawing target 100) relative to the carriage 1.

If the surface shape of the object to be drawn 100 is curved or has an uneven surface shape, the entire carriage 1 moves back and forth along the Z-axis rail 103, and drawing is performed while following the surface shape of the object to be drawn 100.

When one scan's worth of drawing on the forward path is completed, the head holder 70 moves to the negative side in the Z direction and temporarily moves to the standby position as shown on the right side of the figure. While the head holder 70 is in the standby position (cleanable period), the cleaning device 4 moves back and forth in the X direction over the nozzle surface 302a of the head 300.

When the cleaning device 4 moves back and forth, on the outward path, foreign matter is removed using a cleaning agent supply roller 42 and a cleaning blade 43 provided on the cleaning device 4, and on the return path, empty discharge is performed using an empty discharge receiving surface 44 provided on the cleaning device 4.

When cleaning is complete, the carriage 1 moves one scan (line feed) to the negative (or positive) side of the Y direction, and then the head holder 70, which was in the standby position, moves again to the liquid ejection position. After that, the Z-axis rail 103 carrying the carriage 1 moves to the negative side of the X direction along the X-axis rail 101. As the head 300 moves to the negative side of the X direction, it ejects ink toward the drawing object 100, and draws a new image for one scan on the drawing object 100.

When drawing for one scan on the return path is completed, the head holder 70 moves to the negative Z direction and moves to the standby position as shown on the left side of the figure. After that, the cleaning device 4 performs head cleaning in the same manner as described above. The above operations are repeated until drawing is completed.

Figure 13 is an explanatory diagram of the relative positions of each component during the cleaning process.

When cleaning, the cleaning device 4 in the standby position moves in the positive X direction, and the cleaning device 4 starts moving in the forward direction. First, the detergent supply roller 42 of the cleaning device 4 comes into contact with the nozzle surface 302a of the head 300. The idling receiving surface 44 is shifted to the positive Z direction from the contact surface between the detergent supply roller 42 and the nozzle surface 302a, and the idling receiving surface 44 passes directly over the nozzle surface 302a during the forward movement.

The cleaning agent supply roller 42 that has come into contact with the nozzle surface 302a moves over the nozzle surface 302a in the positive X-direction while supplying an organic solvent to the nozzle surface 302a. Following the cleaning agent supply roller 42, the cleaning blade 43 of the cleaning device 4 comes into contact with the nozzle surface 302a, and the cleaning blade 43 scrapes off and removes foreign matter such as residual ink that has adhered to the nozzle surface 302a.

When the cleaning agent supply roller 42 and cleaning blade 43 pass over the nozzle surface 302a and reach the turning point (position indicated by the dashed line in the figure), the cleaning device 4 starts moving in the negative X direction (returning path). On the return path, the nozzle 302 of the head 300 performs an empty discharge toward the empty discharge receiving surface 44 of the cleaning device 4.

In addition, in the case of idling, if the distance between the nozzle surface 302a and the idling receiving surface 44 is too close, the ink is more likely to bounce back and splash. In that case, the cleaning device 4 may be moved to the positive side in the Z direction or the carriage 1 may be moved to the negative side in the Z direction before starting the return movement, and the positions may be corrected to prevent ink splashing.

Figure 14 is an explanatory diagram of foreign matter removal, where Figure 14(a) shows the state before foreign matter removal, Figure 14(b) shows the state during foreign matter removal, and Figure 14(c) shows the state after foreign matter removal.

As shown in FIG. 14(a), after printing, ink (residual ink) M1 ejected from the nozzles 302 during printing is adhered to the nozzle surface 302a of the head 300.

As shown in FIG. 14(b), by supplying a sufficient amount of cleaning agent to the residual ink M1 using the cleaning agent supply roller 42, the adhesion of the residual ink M1 to the nozzle surface 302a decreases, and the residual ink M1 becomes dissolved, becoming residual ink M2.

Then, the dissolved residual ink M2 is scraped off with the cleaning blade 43, and foreign matter including the residual ink is removed from the nozzle surface 302a, as shown in FIG. 14(c).

Figure 15 is an explanatory diagram of the idle discharge, where Figure 15(a) shows the state before the idle discharge starts, Figure 15(b) shows the state when the supply of cleaning agent starts, and Figure 15(c) shows the state during the idle discharge.

As described above, the empty discharge is performed when the cleaning device 4 moves in the return direction. While the cleaning device 4 moves in the forward direction, as shown in FIG. 15(a), no organic solvent is supplied to the empty discharge receiving surface 44.

When the cleaning device 4 starts moving in the return direction, as shown in FIG. 15(b), the supply of organic solvent S1 starts from the second cleaning agent supply port 413. The blank discharge receiving surface 44 moves over the nozzle surface 302a of the head 300 that faces the blank discharge receiving surface 44 while receiving the supply of organic solvent S1.

Each nozzle 302 of the head 300 performs an empty discharge toward the empty discharge receiving surface 44 when it faces the empty discharge receiving surface 44. The organic solvent flowing on the empty discharge receiving surface 44 causes the ink droplets M3 received by the empty discharge receiving surface 44 to flow downward, cleaning the empty discharge receiving surface 44.

The organic solvent that flows down the empty discharge receiving surface 44 flows to a recovery section (not shown) provided below the empty discharge receiving surface 44, and this recovery section discharges the organic solvent to the outside.

In the present invention, the liquid may be a solution, suspension, emulsion, etc., containing a solvent such as water or an organic solvent, a colorant such as a dye or pigment, a functionalizing material such as a polymerizable compound, a resin, or a surfactant, a biocompatible material such as DNA, amino acids, proteins, or calcium, or an edible material such as a natural dye.

These can be used, for example, in inkjet inks, coating materials, surface treatment liquids, components of electronic elements and light-emitting elements, liquids for forming electronic circuit resist patterns, and material liquids for three-dimensional modeling.

The liquid ejection device according to the present invention is not limited to the form of the printing device described above. For example, it may be in a form in which the liquid ejection unit of the present invention is attached to the tip of a robot arm of a multi-joint robot that has multiple joints that allow it to move freely like a human arm. Also, it may be in the form of an unmanned aerial vehicle capable of painting, or a climbing robot capable of painting, by mounting the liquid ejection unit of the present invention on an unmanned aerial vehicle such as a drone, or a robot capable of climbing walls.

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

(Aspect 1)
Aspect 1 is a liquid ejection unit (e.g., carriage 1) that ejects a liquid (e.g., ink) toward an object (e.g., object 100 to be drawn) having a surface that intersects with a horizontal plane (e.g., X-Z plane), and is characterized in that it has a liquid ejection surface (e.g., nozzle surface 302a) that can face the surface that intersects with the horizontal plane, a cleaning device (e.g., cleaning device 4) that cleans the liquid ejection surface, and drive means (e.g., shaft member 3, power transmission belt 5, cleaning device drive unit 94, etc.) that moves the cleaning device relatively to the liquid ejection surface, and the cleaning device has a contact member (e.g., detergent supply roller 42) that is provided so as to be able to come into contact with the liquid ejection surface, and a detergent supply device (e.g., detergent supply unit 41) that supplies a detergent (e.g., an organic solvent) from the surface side of the contact member.

According to aspect 1, it is possible to provide a liquid ejection unit capable of evenly supplying a cleaning agent to a liquid ejection surface that is arranged to face a surface that intersects with a horizontal plane.

(Aspect 2)
Aspect 2 is characterized in that, in aspect 1, the cleaning device (e.g., cleaning device 4) has a contact member (e.g., cleaning blade 43) that contacts the liquid ejection surface (e.g., nozzle surface 302a) after the cleaning agent (e.g., organic solvent) has been supplied, and removes foreign matter (e.g., residual ink M2) from the liquid ejection surface.

According to aspect 2, the cleaning agent supplied by the contact member can reliably remove foreign matter from the liquid ejection surface that has lost its adhesive force to the liquid ejection surface.

(Aspect 3)
Aspect 3 is characterized in that, in aspect 1 or aspect 2, the cleaning device (e.g., cleaning device 4) has a droplet receiving portion (e.g., idling receiving surface 44) for receiving the liquid (e.g., ink) ejected from a liquid ejection port (e.g., nozzle 302) provided on the liquid ejection surface (e.g., nozzle surface 302a).

According to aspect 3, the droplet receiving section can collect foreign matter inside the liquid ejection port and refresh the liquid ejection port.

(Aspect 4)
Aspect 4 is characterized in that in any one of Aspects 1 to 3, the cleaning agent supplying device (e.g., the cleaning agent supplying device 41) supplies the cleaning agent (e.g., an organic solvent) to the droplet receiving portion (e.g., the blank discharge receiving surface 44).

According to aspect 4, it is possible to wash away the liquid received by the droplet receiving portion, thereby preventing the accumulation of liquid in the droplet receiving portion.

(Aspect 5)
Aspect 5 is characterized in that in any one of Aspects 1 to 4, the cleaning agent supplying device (e.g., cleaning agent supply unit 41) has a shutter member (e.g., first shutter 414) on a supply path (e.g., cleaning agent supply pipe 411) of the cleaning agent (e.g., organic solvent) for varying an opening area of the supply path (e.g., opening diameter of the cleaning agent supply pipe 411).

According to aspect 5, the liquid ejection surface can be efficiently cleaned with a minimum amount of cleaning agent.

(Aspect 6)
Aspect 6 is characterized in that in any one of Aspects 1 to 5, the cleaning agent supplying device (e.g., cleaning agent supply unit 41) includes a plurality of cleaning agent supply ports (e.g., first cleaning agent supply port 412) in a direction of a plane intersecting with the horizontal plane (e.g., X-Z plane), and the supply amount of the cleaning agent (e.g., organic solvent) decreases from an upper cleaning agent supply port to a lower cleaning agent supply port.

According to aspect 6, the cleaning agent can be evenly supplied to the contact member even when it is placed vertically.

(Aspect 7)
Aspect 7 is the same as aspect 1, characterized in that the detergent supplying device (e.g., detergent supply unit 41) sprays the detergent onto the contact member (e.g., detergent supply roller 42).

According to aspect 7, the cleaning agent is supplied directly to the outer peripheral surface of the contact member, and the liquid ejection surface can be efficiently cleaned using a small amount of cleaning agent.

1 Carriage (liquid ejection unit)
70 Head holder 300 Head 302 Nozzle (liquid ejection port)
302a Nozzle surface (liquid ejection surface)
4 Cleaning device 41 Cleaning agent supply device (cleaning agent supply device)
42 detergent supply roller (contact member)
43 Cleaning blade (contact member)
44: Blank discharge receiving surface (droplet receiving portion)
411 Cleaning agent supply pipe (supply path)
412: First cleaning agent supply port 413: Second cleaning agent supply port 414: First shutter 415: Second shutter

JP 2012-153152 A

Claims (9)

A liquid ejection unit that ejects liquid toward a target having a surface that intersects with a horizontal plane,
a liquid ejection surface that can face a surface that intersects with the horizontal surface;
a cleaning device for cleaning the liquid ejection surface;
a driving means for moving the cleaning device relative to the liquid ejection surface;
The cleaning device includes:
a contact member provided so as to be able to come into contact with the liquid ejection surface;
a cleaning agent supplying device for supplying a cleaning agent from a surface side of the contact member ;
a droplet receiving portion for receiving the liquid ejected from a liquid ejection port provided on the liquid ejection surface;
having
The liquid ejection unit is characterized in that the cleaning agent supplying device supplies the cleaning agent to the droplet receiving portion . A liquid ejection unit that ejects liquid toward a target having a surface that intersects with a horizontal plane,
a liquid ejection surface that can face a surface that intersects with the horizontal surface;
a cleaning device for cleaning the liquid ejection surface;
a driving means for moving the cleaning device relative to the liquid ejection surface;
With
The cleaning device includes:
a contact member provided so as to be able to come into contact with the liquid ejection surface;
a detergent supplying device for supplying a detergent from the surface side of the contact member;
having
The cleaning agent supply device is provided with a plurality of cleaning agent supply ports in the direction of a surface intersecting the horizontal plane, and the amount of cleaning agent supplied decreases from the upper cleaning agent supply port to the lower cleaning agent supply port . 3. The liquid ejection unit according to claim 1, wherein the cleaning device has a contact member that comes into contact with the liquid ejection surface after the cleaning agent has been supplied, and removes foreign matter from the liquid ejection surface . 3. The liquid ejection unit according to claim 2 , wherein the cleaning device has a droplet receiving portion for receiving the liquid ejected from a liquid ejection port provided on the liquid ejection surface . The liquid ejection unit according to any one of claims 1 to 4, characterized in that the cleaning agent supply device has a shutter member on the cleaning agent supply path that changes the opening area of the supply path. 2. The liquid ejection unit according to claim 1 , wherein the detergent supplying device injects the detergent onto the contact member . A liquid ejection unit that ejects liquid toward a target having a surface that intersects with a horizontal plane,
a liquid ejection surface that can face a surface that intersects with the horizontal surface;
a cleaning device for cleaning the liquid ejection surface;
a driving means for moving the cleaning device relative to the liquid ejection surface;
With
The cleaning device includes:
a contact member provided so as to be able to come into contact with the liquid ejection surface;
a detergent supplying device for supplying a detergent from the surface side of the contact member;
having
The liquid ejection unit is characterized in that the detergent supplying device is provided with a plurality of detergent supplying ports in a direction of a plane intersecting the horizontal plane . A liquid ejection device comprising the liquid ejection unit according to claim 1 . The liquid ejection device according to claim 8, characterized in that the amount of the cleaning agent supplied is controlled in accordance with at least one of the amount of the liquid ejected from the liquid ejection port provided on the liquid ejection surface, the time during which the liquid is not ejected from the liquid ejection port, the type of the liquid, and the environmental temperature and humidity.