JP7681899B2 - Mobile printing device - Google Patents

Description

The present invention relates to a movable printing device that runs over a surface on which a printing area is located and prints. In particular, the present invention relates to a movable printing device that incorporates a printing unit including a print head, a traveling mechanism, and a drive unit that drives the printing unit and the traveling mechanism within the device frame.

Conventionally, various so-called self-propelled printing devices have been proposed as printing devices that print on non-standard printing materials of various sizes and shapes, or on wide printing areas such as the surface of a desk or floor, in addition to standard printing materials such as paper. For example, Patent Document 1 discloses various embodiments, and the printing device disclosed as the first embodiment includes a pair of support tables connected by a support bar and a pair of wheels attached to the lower end of each support table. A cartridge holder that supports a print head and an ink cartridge is slidably attached to the support bar. The cartridge holder is attached to a conveyor belt so as to reciprocate between the two support tables. The wheel drive mechanism, the belt drive mechanism, and the control unit are built into the support table. The pair of wheels attached to each support table are arranged in a row in the front-to-rear direction, which is the direction in which the printing device travels. The printing device can travel on a flat surface on which the printing material is placed by rotating the wheels. Although there is no clear description in Patent Document 1, it is believed that in order for the printing device to move smoothly in the travel direction, each wheel drive mechanism is built into each of the support stands of both support stands.

The printing device disclosed in Patent Document 1 as a fourth embodiment includes a platform on which the printing device of the first embodiment travels. The platform has a pair of guide rails that extend long in the direction of travel. Two pairs of wheels attached to each of the support bases fit into both guide rails, allowing the printing device of the fourth embodiment to travel in the direction in which the guide rails extend.

JP 2000-301775 A

In the printing device disclosed as a first embodiment in Patent Document 1, a pair of wheels are attached to each of the support bases of both support bases and are driven by a wheel drive mechanism that is thought to be built into each support base. However, due to various factors such as the dimensional accuracy of the wheel drive mechanism, the connection accuracy between the wheel drive mechanism and the wheels, and differences in the contact conditions between each wheel and the printing area, the wheels attached to each support base cannot run straight, and the entire printing device may run in a meandering manner.

In the printing device disclosed as the fourth embodiment in Patent Document 1, each pair of wheels attached to each support table fits into each guide rail of the platform and runs. In the fourth embodiment, since two pairs of wheels run along two guide rails, high parallelism of the two guide rails and high fitting accuracy between each wheel and each guide rail are required to reduce meandering of the entire printing device, and each wheel and platform must be manufactured with high dimensional accuracy.

Therefore, the present invention has been made in consideration of the above circumstances, and aims to provide a printing device capable of running with reduced meandering through a simple configuration.

The first aspect of the invention described in claim 1 is a printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to that surface, and prints on the printing area, the printing device comprising: a device frame extending in an orthogonal direction perpendicular to the predetermined traveling direction; a first support part that is arranged at one end of the device frame in the orthogonal direction and rotatably supports a first wheel and a second wheel around a first axis and a second axis extending in the orthogonal direction, a second support part that is arranged at the other end located opposite to the one end of the device frame in the orthogonal direction and rotatably supports a third wheel around a third axis extending in the orthogonal direction; a printing unit that is arranged inside the device frame and prints on the printing area in the orthogonal direction; and a printing unit that is arranged inside the device frame and supports the first wheel and the second wheel. and a wheel drive mechanism that applies a rotational force to at least one of the two wheels, the first support portion supports the first wheel and the second wheel so that the first wheel and the second wheel are arranged in a row with a gap in between in a predetermined running direction, the second support portion supports the third wheel so that the third axis is located between the first axis and the second axis, the wheel widths of the first wheel and the second wheel are determined so that the first wheel and the second wheel each fit into a guide groove of a single guide rail installed on a surface on which the printing area is located or a surface parallel to that surface, the guide groove extending in the predetermined running direction, and when the first wheel and the second wheel fit into the guide groove and run, the third wheel runs in contact with the surface on which the printing area is located or a surface parallel to that surface.

In this aspect of the present invention, the printing unit may be configured so that the print head reciprocates in the perpendicular direction, or the print head may be configured so that it has a long line head in the perpendicular direction. In addition, various printing methods can be used as the printing method of the printing unit. For example, an ink jet printing method or a thermal transfer printing method can be used.

In this embodiment of the present invention, the printing area can be of various shapes and sizes. For example, the printing area can be a scratched area on a floor, an area on clothing where a pattern is to be formed, or a part of a three-dimensional object such as a cake.

In this aspect of the present invention, the surface on which the guide rail is installed may be the same surface as the surface on which the area to be printed is located, or it may be a different surface parallel to the surface on which the area to be printed is located. Also, the surface on which the guide rail is installed may be the upper surface of a dedicated mounting table on which the guide rail is placed. In this case, the dedicated mounting table may be configured to include a mechanism for positioning the printed material, etc.

In this aspect of the present invention, the guide rail may or may not be included as a component of the present invention.

In this aspect of the present invention, when the printing area is a large area such as a floor surface, a single guide rail may be configured by linearly connecting multiple connectable guide rail sections. In this case, the number of connected guide rail sections is determined according to the size of the printing area.

In this aspect of the present invention, the circumferential portions of the first and second wheels and the guide groove must be formed so as to reduce slippage on the surfaces where they come into contact with each other. For example, the surfaces where the circumferential portions of the wheels and the guide groove come into contact with each other may be formed with interlocking concave and convex shapes, or may be formed from a material with a high coefficient of friction.

In this aspect of the present invention, the wheel drive mechanism may be configured to impart a rotational force to only one of the first and second wheels, or may be configured to impart a rotational force to both wheels.

In this aspect of the present invention, the third axis of the third wheel may be located close to the first axis or the second axis, or may be in a central position between the positions of the first axis and the second axis, so long as it is located between the first axis of the first wheel and the second axis of the second wheel.

In this aspect of the invention, the first wheel and the second wheel may have the same diameter or different diameters. Since a slower rotational speed of the third wheel is better for reducing vibrations generated in the second support when the printing device is traveling, it is preferable for the third wheel to have a larger diameter than the first wheel and the second wheel.

The second aspect of the invention described in claim 2 is a printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to the surface and prints on the printing area, the printing device comprising: a device frame extending in an orthogonal direction perpendicular to the predetermined traveling direction; a first support part that is arranged at one end of the device frame in the orthogonal direction and rotatably supports a first wheel and a second wheel around a first axis and a second axis extending in the orthogonal direction; a second support part that is arranged at the other end located opposite to the one end of the device frame in the orthogonal direction and rotatably supports a third wheel around a third axis extending in the orthogonal direction; a printing unit that is arranged inside the device frame and prints on the printing area in the orthogonal direction; a wheel drive mechanism that is arranged inside the device frame and applies a rotational force to one of the first wheel and the second wheel; and a guide having a guide groove extending in the predetermined traveling direction. The rail includes a guide rail that is installed on the surface on which the printed area is located or on a surface parallel to that surface, the first support portion supports the first wheel and the second wheel so that the first wheel and the second wheel are arranged in a row with a gap in a predetermined running direction, the second support portion supports the third wheel so that the third axis is located between the first axis and the second axis, the wheel widths of the first wheel and the second wheel are determined so that the first wheel and the second wheel fit into the guide grooves of the guide rail, the wheel unevenness is formed over the entire circumferential surface of the first wheel and the second wheel, and the guide unevenness is formed over the entire bottom surface of the guide groove so as to mesh with the wheel unevenness of each wheel, and when the first wheel and the second wheel fit into the guide groove and run, the third wheel runs in contact with the surface on which the printed area is located or on a surface parallel to that surface.

As with the first aspect of the invention, this aspect of the invention can be embodied in various ways.

In a specific embodiment described in claim 3, the first wheel and the second wheel are made of a metal material, and the third wheel is made of a material that is more elastic than the first wheel and the second wheel.

In this specific embodiment, in order to absorb vibrations generated in the second support part, it is sufficient that at least a portion of the third wheel is made of a resilient material, but it is preferable that the entire third wheel is made of a resilient material.

In the specific embodiment described in claim 4, the first support part includes a rotating shaft to which the first wheel and the second wheel are fixed and a bearing that rotatably supports the rotating shaft, the second support part includes a fixed shaft that is fixed to the device frame, and the third wheel has a circular hole through which the fixed shaft is inserted.

In this specific embodiment, the rotating shaft to which the first and second wheels are fixed, and the fixed shaft for the third wheel may be supported by a cantilever support configuration or a double-support configuration.

In the specific embodiment described in claim 5, the diameter of the first wheel is set to the same diameter as the diameter of the second wheel, and the diameter of the third wheel is set to a diameter larger than the diameter of the first wheel.

In a specific embodiment described in claim 6, the third axis of the third wheel is located at a central position between the first axis of the first wheel and the second axis of the second wheel.

In the specific embodiment described in claim 7, the wheel drive mechanism includes a drive motor that applies a rotational force to the first wheel and a transmission mechanism that transmits the rotational force of the drive motor to the first wheel, the printing unit includes a carriage that carries an inkjet head and an ink container, and a carriage support mechanism that has a support rail extending in an orthogonal direction and supports the carriage so that it can reciprocate along the support rail, the drive motor is supported by the device frame so as to be located between the first axis of the first wheel and the third axis of the third wheel, and the support rail is supported by the device frame so as to be located between the second axis of the second wheel and the third axis of the third wheel.

In this embodiment, the drive motor may be located close to the first axis or the third axis, or in a central position between the positions of the first axis and the third axis, so long as it is located between the first axis of the first wheel and the third axis of the third wheel. It is also preferable that the majority of the transmission mechanism is located between the first axis and the third axis.

In this specific embodiment, the support rail may be located close to the second axis or the third axis, or may be located centrally between the positions of the second axis and the third axis, so long as the support rail is located between the second axis of the second wheel and the third axis of the third wheel.

In a specific embodiment described in claim 8, the first support portion includes a rotating shaft to which the first and second wheels are fixed, a pair of bearings that rotatably support both ends of the rotating shaft, and a support frame to which the pair of bearings are attached, and the support frame has a mounting plate portion on which a battery for supplying power to the printing unit and the wheel drive mechanism is mounted.

In this specific embodiment, the battery may be configured to be fixed to the device frame or the mounting plate while being placed on the mounting plate, or may be configured to be detachable from the device frame or the mounting plate.

In a specific embodiment described in claim 9, each of the first and second wheels includes a circumferential portion and a pair of side portions located on both sides of the circumferential portion, the guide rail includes a bottom portion and a pair of guide wall portions standing up from both side ends of the bottom portion, the bottom portion and the pair of guide wall portions form a guide groove, and the pair of side portions of each wheel contact the pair of guide wall portions, respectively.

The third aspect of the invention described in claim 10 is a printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to the surface, and prints on the printing area, the printing device comprising: a device frame extending in an orthogonal direction perpendicular to the predetermined traveling direction; a first support part that is arranged at one end of the device frame in the orthogonal direction and rotatably supports a first wheel and a second wheel around a first axis and a second axis extending in the orthogonal direction; a second support part that is arranged at the other end opposite to the one end of the device frame in the orthogonal direction and rotatably supports a third wheel around a third axis extending in the orthogonal direction; a printing unit that is arranged inside the device frame and prints on the printing area in the orthogonal direction; a wheel drive mechanism that is arranged inside the device frame and applies a rotational force to the first wheel; and a control unit that controls the operation of the printing unit and the wheel drive mechanism, and the first wheel and the second wheel are arranged in a row at an interval in the predetermined traveling direction. The first support part supports the first wheel and the second wheel so that the third axis is located between the first axis and the second axis, the wheel width of each of the first wheel and the second wheel is determined so that the first wheel and the second wheel are fitted into a guide groove of a single guide rail installed on a surface on which the area to be printed is located or a surface parallel to that surface, the guide groove extending in a predetermined running direction, and when the first wheel and the second wheel are fitted into the guide groove and run, the third wheel runs in contact with the surface on which the area to be printed is located or a surface parallel to that surface, and the control unit stops the printing operation of the printing unit when it controls the operation of the wheel drive mechanism so that the printing device runs in a first running direction from the first wheel to the second wheel among the predetermined running directions, and causes the printing unit to perform the printing operation when it controls the operation of the wheel drive mechanism so that the printing device runs in a second running direction from the second wheel to the first wheel.

This aspect of the present invention may be embodied in various ways, similar to the first aspect of the invention, the second aspect of the invention, and their specific aspects.

In the specific embodiment described in claim 11, the control unit executes a line printing control process that causes the printing unit to execute a printing operation of one line extending in the perpendicular direction, and a travel control process that causes the wheel drive mechanism to execute a travel operation so that the printing device travels a predetermined line interval in a second travel direction from the second wheel toward the first wheel after the line printing control process is executed.

In the first invention aspect described in claim 1, the first support part is arranged at one end of the device frame in an orthogonal direction perpendicular to a predetermined running direction, and supports the first wheel and the second wheel rotatably around the first axis and the second axis extending in the orthogonal direction. The second support part is arranged at the other end of the device frame in the orthogonal direction, and supports one third wheel rotatably around a third axis extending in the orthogonal direction. The wheel drive mechanism applies a rotational force to at least one of the first wheel and the second wheel. The second support part supports the third wheel so that the third axis is located between the first axis and the second axis. The wheel widths of the first wheel and the second wheel are determined so that the first wheel and the second wheel each fit into a guide groove of a guide rail installed on a surface on which the printing area is located or a surface parallel to that surface. When the first and second wheels fit into the guide grooves and run, the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface. As a result, since the first and second wheels fit into the guide grooves of one guide rail and run, and the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface, compared to a configuration that runs along two guide rails, there is no need for structural precision such as the parallelism of the two guide rails, and the printing device can be run with a simple configuration.

In the first aspect of the invention, since one third wheel is arranged at the other end of the device frame, the printing device can run straighter in the running direction than in a configuration in which two wheels are arranged at the other end of the device frame. In other words, when two wheels are arranged at the other end of the device frame, differences in the rotational state of the two wheels may occur, such as the two wheels rotating around axes that are not parallel to each other, due to differences in dimensional accuracy and assembly accuracy to the device frame. This difference in the rotational state of the two wheels may generate running resistance at the other end of the device frame, but in the first aspect of the invention, since one third wheel is arranged at the other end of the device frame, running resistance at the other end of the device frame can be reduced.

In the first aspect of the invention, since the third axis is located between the first and second axes, the running resistance at the other end of the device frame can be reduced compared to a configuration in which the third axis is located outside the range between the first and second axes. That is, according to the inventor's running experiments, the experimental results show that the error between the spacing between the lines printed at one end of the device frame and the spacing between the lines printed at the other end of the device frame in a configuration in which the third axis is located between the first and second axes is smaller than the error in a configuration in which the third axis is located outside the range between the first and second axes. This shows that the configuration in which the third axis is located between the first and second axes reduces the running resistance at the other end of the device frame.

In the second invention aspect described in claim 2, the first support part is arranged at one end of the device frame in an orthogonal direction perpendicular to the predetermined running direction, and supports the first wheel and the second wheel rotatably around the first axis and the second axis extending in the orthogonal direction. The second support part is arranged at the other end of the device frame in the orthogonal direction, and supports one third wheel rotatably around a third axis extending in the orthogonal direction. The wheel drive mechanism applies a rotational force to one of the first wheel and the second wheel. The second support part supports the third wheel so that the third axis is located between the first axis and the second axis. The wheel widths of the first wheel and the second wheel are determined so that the first wheel and the second wheel each fit into the guide groove of one guide rail. When the first wheel and the second wheel fit into the guide groove and run, the third wheel runs in contact with the surface on which the printing area is located or a surface parallel to that surface. The guide rail is installed on the surface on which the printed area is located or on a surface parallel to that surface so that the guide groove extends in a predetermined running direction. The second support part supports the third wheel so that the third axis is located between the first axis and the second axis. The wheel unevenness is formed on the entire circumferential surface of each of the first and second wheels, and the guide unevenness is formed on the entire bottom surface of the guide groove so as to mesh with the wheel unevenness of each wheel. When the first and second wheels fit into the guide groove and run, the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface. As a result, since the first and second wheels fit into the guide groove of one guide rail and run, and the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface, compared to a configuration in which the printing device runs along two guide rails, there is no need for structural precision such as the parallelism of the two guide rails, and the printing device can be run with a simple configuration.

In the second aspect of the invention, since one third wheel is arranged at the other end of the device frame, the printing device can run straighter in the running direction than in a configuration in which two wheels are arranged at the other end of the device frame. In other words, when two wheels are arranged at the other end of the device frame, differences in the rotational state of the two wheels may occur, such as the two wheels rotating around axes that are not parallel to each other, due to differences in dimensional accuracy and assembly accuracy to the device frame. This difference in the rotational state of the two wheels may generate running resistance at the other end of the device frame, but in the second aspect of the invention, since one third wheel is arranged at the other end of the device frame, running resistance at the other end of the device frame can be reduced.

In the second aspect of the invention, since the third axis is located between the first and second axes, the running resistance at the other end of the device frame can be reduced compared to a configuration in which the third axis is located outside the range between the first and second axes. That is, according to the inventor's running experiments, the experimental results show that the error between the spacing between the lines printed at one end of the device frame and the spacing between the lines printed at the other end of the device frame in a configuration in which the third axis is located between the first and second axes is smaller than the error in a configuration in which the third axis is located outside the range between the first and second axes. This shows that the configuration in which the third axis is located between the first and second axes reduces the running resistance at the other end of the device frame.

In the second aspect of the invention, since the wheel drive mechanism is configured to apply a rotational force to one of the first and second wheels, the overall configuration of the wheel drive mechanism can be simplified in terms of the mechanical coupling configuration and rotation control configuration compared to a configuration in which a rotational force is applied to both the first and second wheels. In addition, the wheel unevenness is formed over the entire circumferential surface of each of the first and second wheels, and the guide unevenness is formed over the entire bottom surface of the guide groove so as to engage with the wheel unevenness of each wheel, so that the first and second wheels can run straight along the guide rail. Furthermore, the other wheel of the first and second wheels to which no rotational force is applied can rotate freely, so that the wheel unevenness of the other wheel can be reliably engaged with the guide unevenness, making it easy to mount the printing device on the guide rail.

In the specific embodiment described in claim 3, the first wheel and the second wheel are made of a metal material, and the third wheel is made of a material that is more elastic than the first wheel and the second wheel. As a result, the third wheel can reduce vibrations that occur at the other end of the device frame. That is, when the third wheel rotates while receiving running resistance, vibrations may occur at the other end of the device frame. In this specific embodiment, because the third wheel is made of an elastic material, vibrations at the other end of the device frame can be quickly reduced, and the printing accuracy of the printing device can be improved.

In the specific embodiment described in claim 4, the first support part includes a rotating shaft to which the first and second wheels are fixed and a bearing that rotatably supports the rotating shaft, the second support part includes a fixed shaft that is fixed to the device frame, and the third wheel has a circular hole through which the fixed shaft is inserted. As a result, the third wheel rotates in direct contact with the fixed shaft through the circular hole, and therefore, compared to a configuration in which the third wheel is supported by a bearing, the third wheel rotates while always experiencing slight contact resistance due to contact with the fixed shaft, and it is possible to reduce disturbance of the running posture at the other end of the device frame due to the inertial force acting on the third wheel when the third wheel rotates or stops.

In the specific embodiment described in claim 5, the diameter of the first wheel is set to the same diameter as the diameter of the second wheel, and the diameter of the third wheel is set to a diameter larger than the diameter of the first wheel. As a result, the first wheel and the second wheel that fit into the guide groove of the guide rail can be rotated at the same rotational speed, and the third wheel can be rotated at a rotational speed lower than the rotational speed of the first wheel and the second wheel, and vibrations generated at the other end of the device frame due to the rotational state of the third wheel can be reduced. In addition, by setting the diameter of the third wheel to a diameter larger than the diameter of the first wheel, vibrations generated in the third wheel during the running of the printing device can be reduced compared to a configuration in which the diameter of the third wheel is set to a diameter smaller than the diameter of the first wheel.

In the specific embodiment described in claim 6, the third axis of the third wheel is located at a central position between the first axis of the first wheel and the second axis of the second wheel. As a result, a three-point support structure is adopted by the first wheel, the second wheel, and the third wheel, which stably supports the device frame and reduces the running resistance when the printing device is running.

In the specific embodiment described in claim 7, the wheel drive mechanism includes a drive motor that applies a rotational force to the first wheel and a transmission mechanism that transmits the rotational force of the drive motor to the first wheel, and the printing unit includes a carriage that carries an inkjet head and an ink container, and a carriage support mechanism that has a support rail extending in an orthogonal direction and supports the carriage so that it can reciprocate along the support rail, and the drive motor is supported by the device frame so as to be located between the first axis of the first wheel and the third axis of the third wheel, and the support rail is supported by the device frame so as to be located between the second axis of the second wheel and the third axis of the third wheel. As a result, the drive motor, which is a heavy object in the wheel drive mechanism, and the support rail, which is a heavy object in the printing unit and requires a large arrangement space, are arranged separately in the area between the first axis and the third axis and the area between the second axis and the third axis inside the device frame, so that the weight balance of the printing device in a predetermined running direction can be achieved, and the running operation of the printing device can be stabilized.

In a specific embodiment described in claim 8, the first support portion includes a rotating shaft to which the first and second wheels are fixed, a pair of bearings that rotatably support both ends of the rotating shaft, and a support frame to which the pair of bearings are attached, and the support frame has a mounting plate portion on which a battery for supplying power to the printing unit and the wheel drive mechanism is mounted. As a result, when the battery is placed on the mounting plate portion, the first and second wheels can be pressed against the guide rail with a large force due to the weight of the battery, and the first and second wheels can be accurately driven along the guide rail.

In a specific embodiment described in claim 9, each of the first and second wheels includes a circumferential portion and a pair of side portions located on both sides of the circumferential portion, and the guide rail includes a bottom portion and a pair of guide wall portions standing up from both side ends of the bottom portion, and the bottom portion and the pair of guide wall portions form a guide groove, and the pair of side portions of each wheel contact the pair of guide wall portions, respectively. As a result, since the pair of side portions of each wheel contact the pair of guide wall portions, respectively, the first and second wheels can be made to run straight along the guide rail without meandering.

In the third invention aspect described in claim 10, the first support part is arranged at one end of the device frame in an orthogonal direction perpendicular to the predetermined running direction, and supports the first wheel and the second wheel rotatably around the first axis and the second axis extending in the orthogonal direction. The second support part is arranged at the other end of the device frame in the orthogonal direction, and supports one third wheel rotatably around a third axis extending in the orthogonal direction. The wheel drive mechanism applies a rotational force to the first wheel. The control unit controls the operation of the printing unit and the wheel drive mechanism. The second support part supports the third wheel so that the third axis is located between the first axis and the second axis. The wheel widths of the first wheel and the second wheel are determined so that the first wheel and the second wheel each fit into a guide groove of a guide rail installed on a surface on which the printing area is located or a surface parallel to that surface. When the first wheel and the second wheel are fitted into the guide groove and run, the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface. When the control unit controls the operation of the wheel drive mechanism so that the printing device runs in a first running direction from the first wheel to the second wheel among the predetermined running directions, the control unit stops the printing operation of the printing unit, and when the control unit controls the operation of the wheel drive mechanism so that the printing device runs in a second running direction from the second wheel to the first wheel, the control unit causes the printing unit to execute the printing operation. As a result, since the first wheel and the second wheel are fitted into the guide groove of one guide rail and run, and the third wheel runs in contact with the surface on which the printed area is located or a surface parallel to that surface, compared to a configuration in which the printing device runs along two guide rails, there is no need for structural precision such as the parallelism of the two guide rails, and the printing device can be run with a simple configuration.

In the third aspect of the invention, since one third wheel is arranged at the other end of the device frame, the printing device can be made to run straighter in the running direction than in a configuration in which two wheels are arranged at the other end of the device frame. In other words, when two wheels are arranged at the other end of the device frame, differences in the rotational state of the two wheels may occur, such as the two wheels rotating around axes that are not parallel to each other, due to differences in dimensional accuracy and assembly accuracy to the device frame. This difference in the rotational state of the two wheels may generate running resistance at the other end of the device frame, but in the third aspect of the invention, since one third wheel is arranged at the other end of the device frame, running resistance at the other end of the device frame can be reduced.

In the third aspect of the invention, since the third axis is located between the first and second axes, the running resistance at the other end of the device frame can be reduced compared to a configuration in which the third axis is located outside the range between the first and second axes. That is, according to the inventor's running experiments, the experimental results show that the error between the spacing between the lines printed at one end of the device frame and the spacing between the lines printed at the other end of the device frame in a configuration in which the third axis is located between the first and second axes is smaller than the error in a configuration in which the third axis is located outside the range between the first and second axes. This shows that the configuration in which the third axis is located between the first and second axes reduces the running resistance at the other end of the device frame.

In the third aspect of the invention, since the wheel drive mechanism is configured to apply a rotational force to the first wheel out of the first and second wheels, the overall configuration of the wheel drive mechanism can be simplified in a mechanical coupling configuration or a rotation control configuration compared to a configuration in which a rotational force is applied to both the first and second wheels. Also, when the printing device travels in the second traveling direction, the second and third wheels rotate following the travel caused by the rotation of the first wheel to which the rotational force is applied, so that the direction and travel amount of the travel caused by the following rotation of the second and third wheels can be stabilized compared to when the printing device travels in the first traveling direction. In the third aspect of the invention, when the control unit controls the operation of the wheel drive mechanism so that the printing device travels in the second traveling direction in which the travel caused by the following rotation of the second and third wheels is stable, the control unit causes the printing unit to execute a printing operation, so that the printing device can print with precision at a specified position.

In the specific aspect described in claim 11, the control unit executes a line printing control process that causes the printing unit to execute a printing operation of one line extending in the perpendicular direction, and a travel control process that causes the wheel drive mechanism to execute a travel operation so that the printing device travels a predetermined line interval in the second travel direction from the second wheel toward the first wheel after the line printing control process is executed. As a result, since the travel control process is executed after the line printing control process is executed, it is possible to reduce fluctuations in the printing position in the printed area due to the travel operation of the printing device.

1 is a perspective view showing an overall configuration of a printing run assembly 1 according to an embodiment of the present invention. This is a front view of the printing run assembly 1, in which the running main body 2 is attached to the guide rail 3, when the guide rail 3 of the printing run assembly 1 is installed on the upper surface 4A of the floor 4. 3 is a plan view showing the internal configuration of the traveling main body 2 mounted on the guide rail 3 as shown in FIG. 2. FIG. 2 is a perspective view of the traveling main body 2 removed from the guide rail 3, as viewed from below. FIG. 2 is a block diagram showing the electrical configuration of the traveling main body 2. FIG. 4 is a flowchart showing a main control process of the traveling main body unit 2.

[Embodiment]
A traveling printing assembly 1 according to an embodiment of the present invention will be described below with reference to the drawings. The traveling printing assembly 1 includes a traveling main body 2 and one guide rail 3. The traveling printing assembly 1 is a device that prints on non-standard printing materials having various sizes and shapes, or on a wide printing area such as the surface of a desk or a floor surface, in addition to standard printing materials such as paper. For example, when printing a color image matching the pattern and color of the floor surface in the peripheral area of the scratch to repair a scratch on the floor surface, the user installs the guide rail 3 in a position close to the peripheral area of the scratch and attaches the traveling main body 2 to the guide rail 3. Since the traveling main body 2 has a built-in printing unit described later, it is possible to print a color image in the peripheral area of the scratch while traveling along the guide rail 3. FIG. 1 shows the overall configuration of the traveling printing assembly 1. The up-down direction, the left-right direction, and the front-rear direction are the directions indicated by arrows in FIG. 1, and are similarly indicated in other drawings from FIG. 2 onwards.

<Detailed configuration of guide rail 3>
The detailed configuration of the guide rail 3 will be described with reference to Figs. 1 to 3. Fig. 1 is a perspective view showing the overall configuration of the running printing assembly 1 with the floor 4 omitted for convenience of illustration. Fig. 2 is a front view showing the printing running assembly 1 in which the running main body 2 is attached to the guide rail 3 when the guide rail 3 is installed on the upper surface 4A of the floor 4. Fig. 3 is a plan view showing the internal configuration of the running main body 2 attached to the guide rail 3. As shown in Fig. 2, the user installs one guide rail 3 on the upper surface 4A of the floor 4. The position where the guide rail 3 is installed is a position on the upper surface 4A of the floor 4 close to the printed area where there is a part to be repaired such as a scratch.

As shown in FIG. 1, the guide rail 3 is elongated and extends in the front-rear direction. The guide rail 3 mainly comprises a base plate portion 10, a guide bottom portion 12 fixed to the base plate portion 10, and a pair of guide walls 14, 16 rising upward from the guide bottom portion 12. A toothed belt 18 is attached to the guide bottom portion 12. The guide bottom portion 12 and both guide walls 14, 16 form a guide groove of the guide rail 3. Both guide walls 14, 16 are arranged opposite each other in the left-right direction and extend parallel to each other in the front-rear direction. The toothed belt 18 is arranged in the entire area of the guide bottom portion 12 that forms the guide groove extending in the front-rear direction. A pair of anti-slip members 20, 22 are attached to the underside of the base plate portion 10 near the front end and the rear end, respectively. One guide rail 3 is stably supported by two points supported by both anti-slip members 20, 22.

As shown in Figs. 2 and 3, a detection piece 24 for detecting the travel origin is fixed to the upper surface of the rear end of the base plate portion 10, in an area to the left of the guide wall portion 16. When the detection piece 24 stands upright from the upper surface of the base plate portion 10, as shown in Fig. 3, it extends forward a predetermined length from the rear end of the base plate portion 10.

In this embodiment, the length of one guide rail 3 in the front-to-rear direction is set to about 1 meter. Since it is preferable that the length of the guide rail 3 in the front-to-rear direction be changed depending on the length of the printing area in the front-to-rear direction, guide rails 3 of multiple lengths may be prepared.

<<Detailed configuration of the traveling main body 2>>
The detailed mechanical configuration of the traveling main body 2 will be described with reference to Figs. 1 to 4. Fig. 4 is a perspective view of the traveling main body 2 removed from the guide rail 3, as seen from below. The traveling main body 2 is detachable from the single guide rail 3, and is configured to be transportable by the user. That is, when there are many scratches on the upper surface 4A of a large floor 4 such as a gymnasium, after repairing one scratch, the user can transport and set up the single guide rail 3 and the traveling main body 2 to a printing area where another scratch exists.

The running main body unit 2 mainly comprises a main body frame 30, a first wheel 32, a second wheel 34, a third wheel 36, a wheel drive mechanism 38, and a printing unit 40. The main body frame 30 has a box shape that is long in the left-right direction. A handle 42 is fixed to the top surface of the main body frame 30. A user can carry the running main body unit 2 by holding the handle 42.

<Detailed Configuration of Main Body Frame 30>
The detailed configuration of the main body frame 30 will be described. The main body frame 30 mainly includes a base frame portion 44, an upper panel portion 46, a right support plate portion 48, a left support plate portion 50, and a wheel support frame portion 52. As shown in FIG. 1, the main body frame 30 has a front opening so that the front is open. As shown in FIG. 2, the right support plate portion 48 stands upright from the right end of the base frame portion 44 and extends upward, and the left support plate portion 50 stands upright from the left end of the base frame portion 44 and extends upward. The upper panel portion 46 is fixed to both upper ends of the right support plate portion 48 and the left support plate portion 50. The wheel support frame portion 52 is bent into an inverted U-shape and is formed from a plate material of a magnetic material. The wheel support frame portion 52 is fixed to the right support plate portion 48 while being located to the right of the right support plate portion 48. The wheel support frame portion 52 mainly comprises a mounting plate portion 54 and a pair of hanging portions 56 , 58 .

As shown in FIG. 1, the battery 60 is placed on the upper surface of the mounting plate portion 54. The battery 60 is a power source that supplies power to the control portion and drive portion of the traveling main body portion 2. A magnetic sheet (not shown) is attached to the underside of the battery 60. This magnetic sheet is attracted to the mounting plate portion 54, which is made of a magnetic material, so that the battery 60 is detachably attached to the mounting plate portion 54.

<Detailed configuration of the first wheel 32, the second wheel 34, and the mechanism supporting both wheels>
The detailed configuration of the first wheel 32, the second wheel 34, and the mechanism supporting both wheels will be described with reference to Figures 3 and 4. Note that, for convenience of illustration, in Figure 3, of the pair of hanging parts 56, 58 of the wheel support frame part 52, only the hanging part 56 is shown, and the hanging part 58 is omitted.

The first wheel 32 and the second wheel 34 are made of aluminum material and have the same circular shape and the same dimensions. A toothed portion is continuously formed on the entire circumference of each of the first wheel 32 and the second wheel 34. The toothed portion of each wheel can mesh with the toothed portion of the toothed belt 18 of the guide rail 3. In this embodiment, the diameter of the pitch circle of the toothed portion of each of the first wheel 32 and the second wheel 34 is set to approximately 38.8 mm, and the width of each wheel is set to 14 mm.

The first wheel 32 has a circumferential portion where the toothed portion is formed, and a pair of side portions 32A, 32B located on either side of the circumferential portion. Similarly, the second wheel 34 has a circumferential portion where the toothed portion is formed, and a pair of side portions 34A, 34B located on either side of the circumferential portion. The width of each wheel is the dimension between the two side portions. Each wheel fits into the guide groove of the guide rail 3 with the pair of side portions of each wheel contacting the inner wall portions of the pair of guide wall portions 14, 16 of the guide rail 3, respectively.

The first wheel 32 is fixed to the first rotating shaft 62. The pair of bearings 64, 66 are fixed to the pair of hanging parts 56, 58 of the wheel support frame part 52, as shown in FIG. 4. The first rotating shaft 62 is rotatably supported by the two bearings 64, 66 in a state in which the first axis AX1 of the first rotating shaft 62 extends in the left-right direction. The second wheel 34 is fixed to the second rotating shaft 68. The pair of bearings 70, 72 are fixed to the pair of hanging parts 56, 58 of the wheel support frame part 52, as shown in FIG. 4. The second rotating shaft 68 is rotatably supported by the two bearings 70, 72 in a state in which the second axis AX2 of the second rotating shaft 68 extends in the left-right direction. As shown in FIG. 3, the first wheel 32 and the second wheel 34 are arranged in a row at a predetermined interval in the front-rear direction, which is the running direction of the running main body part 2. In this embodiment, the predetermined distance between the two wheels 32, 34, i.e., the distance between the first axis AX1 and the second axis AX2, is about four times the diameter of the pitch circle of each of the two wheels 32, 34, and is set to about 1/3 to 1/4 of the left-right length of the running main body 2 so that the running main body 2 can run stably in a straight line.

<Detailed configuration of the third wheel 36 and the mechanism supporting the wheel>
The third wheel 36 is molded into a circular shape by a material having a greater elasticity than the first wheel 32. The third wheel 36 has a smooth circumferential surface and a through hole 74 in the center. In this embodiment, urethane rubber having a rubber hardness of "60" is used as the elastic material of the third wheel 36. To measure the hardness of the rubber, a type A durometer suitable for measuring a medium hardness is used. The hardness of the rubber is not limited to the hardness of "60" as long as it is a hardness that can suppress the elastic deformation of the third wheel 36 while the third wheel 36 is rotating and running. The diameter of the third wheel 36 is set to a diameter larger than the diameter of the first wheel 32. In this embodiment, the diameter of the third wheel 36 is set to 60 millimeters so that the upper end of the third wheel 36 does not protrude upward from the upper panel portion 46 of the main body frame 30 shown in FIG. 2. The width of the third wheel 36 is set to 13 millimeters, which is slightly smaller than the width of the first wheel 32.

The fixed shaft 76 is fixed to the left support plate 50 of the main body frame 30 with the third axis AX3 of the fixed shaft 76 extending in the left-right direction. When the through hole 74 of the third wheel 36 is fitted onto the fixed shaft 76, the third wheel 36 is prevented from coming off the fixed shaft 76 by a mounting screw (not shown) in FIG. 3. The third wheel 36 is supported rotatably around the fixed shaft 76.

The fixed shaft 76 is disposed on the left support plate 50 so that the third axis AX3 of the fixed shaft 76 is located between the first axis AX1 of the first wheel 32 and the second axis AX2 of the second wheel 34 in the front-rear direction, as shown in FIG. 3. In this embodiment, the third axis AX3 is located at the center position between the first axis AX1 and the second axis AX2. Also, in FIG. 2, when the running printing assembly 1 is disposed on the upper surface 4A of the floor 4, the first wheel 32 and the second wheel 34 fit into the guide groove of the guide rail 3, and the toothed portion of each wheel meshes with the toothed portion of the toothed belt 18 of the guide rail 3 installed on the upper surface 4A of the floor 4. The third wheel 36 directly contacts the upper surface 4A of the floor 4. When the third wheel 36 is in contact with the upper surface 4A, the fixed shaft 76 is positioned on the left support plate 50 in the vertical direction so that the running main body 2 is parallel to the upper surface 4A of the floor 4, i.e., horizontal.

<Detailed Configuration of Wheel Drive Mechanism 38>
The detailed configuration of the wheel drive mechanism 38 will be described with reference to Fig. 3. The wheel drive mechanism 38 is a mechanism that applies a rotational force to the first wheel 32, and is disposed on the base frame portion 44 of the main body frame 30. The wheel drive mechanism 38 mainly includes a travel motor 80 and a travel transmission mechanism 82. The travel motor 80 is configured as a DC motor, and is fixed to the base frame portion 44 via a mounting frame 84.

The traveling transmission mechanism 82 is a mechanism that transmits the rotational force of the traveling motor 80 to the first rotating shaft 62 to which the first wheel 32 is fixed. The traveling transmission mechanism 82 mainly includes a small diameter gear 86, a large diameter gear 88, a drive shaft 90, a small diameter pulley 92, a large diameter pulley 94, and a transmission belt 96. The small diameter gear 86 is fixed to the output shaft of the traveling motor 80. The drive shaft 90 is rotatably supported by the mounting frame 84. The large diameter gear 88 is fixed to the left end of the drive shaft 90 and meshes with the small diameter gear 86. The small diameter pulley 86 is fixed to the right end of the drive shaft 90. The large diameter pulley 94 is fixed to the left end of the first rotating shaft 62 that protrudes leftward from the right support plate portion 48 of the main body frame 30. The transmission belt 96 is stretched between the small diameter pulley 92 and the large diameter pulley 94. In this embodiment, the small diameter gear 86 and the large diameter gear 88 are made of helical gears so that the traveling transmission mechanism 82 can transmit power smoothly and quietly. In order to rotate the first wheel 32 with precision, the small diameter pulley 92 and the large diameter pulley 94 are made of toothed timing pulleys, and the transmission belt 96 is made of a toothed timing belt.

In this embodiment, as shown in FIG. 3, the travel motor 80 and most of the travel transmission mechanism 82, except for a portion of the large diameter gear 88, are disposed in the area between the first axis AX1 and the third axis AX3 in the front-rear direction.

<Detailed Configuration of Printing Unit 40>
2 to 4, the detailed configuration of the printing unit 40 will be described. The printing unit 40 mainly includes an inkjet printing section 100, a carriage 102, a carriage support mechanism 104, and a carriage drive mechanism 106. As shown in FIG. 1, the printing unit 40 is disposed in a position close to a front opening of the main body frame 30, which opens forward.

The carriage support mechanism 104 is fixed to the base frame portion 44 of the main frame 30, and includes an upper support rail 108, a lower support rail 110, and a connecting plate portion 112 that connects the two rails 108, 110. The upper support rail 108 extends long in the left-right direction and has a bent edge portion that is bent downward at the front. The lower support rail 110 extends long in the left-right direction in a state parallel to the upper support rail 108, and has a bent edge portion that is bent upward at the front. The carriage 102 includes an engagement portion that engages with both bent edges of the two support rails 108, 110, respectively, and is arranged so as to be able to reciprocate left-right along the two support rails 108, 110.

The inkjet printing unit 100 is mounted on the carriage 102. In this embodiment, the inkjet printing unit 100 includes two cartridges that are replaceably mounted on the carriage 102. Each cartridge has a known configuration in which an inkjet head and an ink container are integrated. The two cartridges are a cartridge 114 for black ink and a cartridge 116 for three color inks. Cartridge 114 is equipped with an inkjet head 114A for black ink, and cartridge 116 is equipped with an inkjet head 116A for color inks. Each cartridge has a built-in ink level sensor that detects the amount of ink remaining in the ink container.

The carriage drive mechanism 106 mainly includes a carriage motor 120 and a carriage transmission mechanism 122 shown in FIG. 3. The carriage motor 120 is composed of a DC motor and is fixed to the connecting plate portion 120 of the carriage support mechanism 104. The carriage transmission mechanism 122 includes a drive pulley 124, a driven pulley (not shown), and a transmission belt 126. The drive pulley 124 is fixed to the output shaft of the carriage motor 120 protruding forward from the connecting plate portion 120. The driven pulley is rotatably supported by the connecting plate portion 120 at a position close to the position where the carriage 102 shown in FIG. 2 stops. The transmission belt 126 is stretched between the drive pulley 124 and the driven pulley. The carriage 102 is connected to the transmission belt 126 and reciprocates in the left and right directions as the carriage motor 120 rotates. In this embodiment, in order to move the carriage 102 with precision, the drive pulley 124 and the driven pulley are made of toothed timing pulleys, and the transmission belt 126 is made of a toothed timing belt.

In this embodiment, as shown in FIG. 3, the carriage support mechanism 104 including the upper support rail 108 and the lower support rail 110 is disposed in the area between the second axis line AX2 and the third axis line AX3 in the front-rear direction.

<Detailed configuration of various sensors>
The detailed configuration of the various sensors will be described with reference to the drawings. In this embodiment, an encoder 200 and a travel origin sensor 210 are provided to execute the operation of the traveling main body 2 traveling in the forward and backward direction, which is the traveling direction. In addition, a timing sensor 220 is provided to execute the operation of the carriage 102 reciprocating in the left and right direction when performing a printing operation.

The encoder 200 includes a rotating body 202 and a photosensor 204. As shown in FIG. 3, the rotating body 202 is fixed to the left end of the drive shaft 90 of the travel transmission mechanism 82. The rotating body 202 is composed of a disk with multiple slits formed in the circumferential direction. The photosensor 204 is fixed to the mounting frame 84 of the travel transmission mechanism 82 by a mounting member. The photosensor 204 detects the slits of the rotating body 202 and generates a pulse signal with a number of pulses corresponding to the amount of rotation of the rotating body 202 and a frequency corresponding to the rotation speed of the rotating body 202.

The travel origin sensor 210 includes a detection piece 24 fixed to the guide rail 3, and a photosensor 212. As shown in FIG. 4, the photosensor 212 is fixed to the base frame portion 44 of the main body frame 30 by a mounting member so as to be positioned between the hanging portions 56, 58 of the wheel support frame portion 52. The photosensor 212 generates a detection signal corresponding to the detection state of the detection piece 24.

The timing sensor 220 includes a timing fence 222 and a photosensor (not shown). As shown in FIG. 2, the timing fence 222 is attached to the connecting plate portion 112 of the carriage support mechanism 104, and is arranged so as to extend long in the left-right direction over a left-right area that exceeds the entire reciprocating motion range of the carriage 102. The timing fence 222 is composed of a strip-shaped body with many slits arranged in the left-right direction. The photosensor of the timing sensor 220 is mounted on the carriage 102, detects the slits of the timing fence 222, and generates a pulse signal with a number of pulses corresponding to the amount of left-right movement of the carriage 102.

Electrical configuration of the traveling main body 2
The electrical configuration of the traveling main body 2 will be described with reference to FIG. 5. FIG. 5 is a block diagram showing the electrical configuration of the traveling main body 2. In FIG. 5, the traveling main body 2 mainly includes a main control unit 230 including at least one CPU, a program memory 232, a working memory 234 such as a RAM, a power input unit 236, a communication interface 238, a display operation unit 240, a traveling control unit 242, a carriage control unit 244, and a head control unit 246. As shown in FIG. 3, a circuit board 250 on which the power circuit and the control circuit of the traveling main body 2 are formed is accommodated inside the main body frame 30. The traveling main body 2 is configured to be able to communicate with a personal computer 300, which is an external information processing device. For example, when the communication interface 238 is connected to the communication interface 302 of the personal computer 300 via a wired or wireless communication network, the traveling main body 2 can receive image information created by the personal computer 300 from the personal computer 300. For example, the image information may be color image information of a predetermined image size that represents the color and pattern of the upper surface 4A of a predetermined floor area in order to repair a scratch on the upper surface 4A of the floor 4.

The program memory 232 stores various programs, such as the main control program that executes the main control process shown in FIG. 6, and various fixed values that are parameters required for control. The working memory 234 temporarily stores color image information received from the personal computer 300 and the results of calculation processing associated with the execution of the programs. The power supply input unit 236 is connected to the battery 60 and supplies a predetermined DC voltage to various circuit elements such as the main control unit 230. In this embodiment, the power supply input unit 236 is configured to be connectable to an AC-DC converter instead of the battery 60. The power supply input unit 236 is equipped with a main power switch (not shown).

As shown in FIG. 1, the display operation unit 240 includes a power switch 250, a status indicator lamp 252, an error lamp 254, and a power lamp (not shown). When the main power-on switch is turned on, the power switch 250 is turned on to supply power to various circuit elements such as the main control unit 230, and the power lamp lights up. The status indicator lamp 252 lights up and blinks to indicate the reception status of image information from the personal computer 300, etc. The error lamp 254 lights up when an error occurs, such as when the remaining ink level falls below a predetermined level.

The travel control unit 242 controls the rotation and stopping, rotation direction, rotation amount, and rotation speed of the travel motor 80 according to the control command from the main control unit 230, the pulse signal from the encoder 200, and the detection signal from the travel origin sensor 210. The carriage control unit 244 controls the rotation and stopping, rotation direction, rotation amount, and rotation speed of the carriage motor 120 according to the control command from the main control unit 230 and the pulse signal from the timing sensor 220. The head control unit 246 controls the ink ejection operation of the inkjet heads 112A and 114A according to the control command and image information from the main control unit 230, and transmits the detection result to the main control unit 230 according to the detection signal from the ink remaining amount sensor (not shown) built into the cartridges 114 and 116.

<<Operation and Function of the Embodiment>>
The operation and function of the running printing assembly 1 of this embodiment will be described mainly with reference to Fig. 6. Fig. 6 is a flow chart showing the main control process. Each step S1 to S12 shown in Fig. 6 is a process executed by the CPU of the main control unit 230.

First, the user installs the guide rail 3 around the location where the scratch is present on the upper surface 4A of the floor 4. After installing the guide rail 3, the user attaches the running main body 2 to the guide rail 3 so that the first wheel 32 and the second wheel 34 fit into the guide grooves of the guide rail 3.

After mounting the traveling main body 2, the user turns on the main power switch, and then turns on the power switch 250. By turning on the power switch 250, power is supplied to various circuit elements such as the main control unit 230. When this power supply starts, the main control unit 230 starts executing the main control program. When execution of the main control program starts, well-known initialization operations such as clearing all memory areas of the working memory 234 are performed.

After the initialization operation, the operation of detecting the travel origin is performed (S1). Specifically, when the photo sensor 212 of the travel origin sensor 210 detects the presence of the detection piece 24 at the start of the power supply, the main control unit 230 transmits a control command to the travel control unit 242 so that the travel motor 80 rotates in a predetermined forward direction to move the travel main body unit 2 forward. When the photo sensor 212 detects a change from the presence of the detection piece 24 to its absence, the main control unit 230 transmits a control command to the travel control unit 242 so that the travel motor 80 rotates in a predetermined reverse direction to move the travel main body unit 2 backward. When the photo sensor 212 detects a change from the absence of the detection piece 24 to its presence, the main control unit 230 transmits a stop command for the travel motor 80 to the travel control unit 242. The position in the forward/rearward direction at which the travel main body unit 2 is located at the time when the travel motor 80 stops in accordance with this stop command is the travel origin position of the travel main body unit 2.

When the photo sensor 212 of the travel origin sensor 210 detects the absence of the detection piece 24 at the start of the power supply, the main control unit 230 sends a control command to the travel control unit 242 so that the travel motor 80 rotates in a predetermined reverse direction to move the travel main body unit 2 backwards. When the photo sensor 212 detects a change from the absence to the presence of the detection piece 24, the main control unit 230 sends a command to the travel control unit 242 to stop the travel motor 80. The position in the fore-and-aft direction at which the travel main body unit 2 is located at the time when the travel motor 80 stops in accordance with this stop command is the travel origin position of the travel main body unit 2.

A positioning operation to the travel standby position is performed (S2). Specifically, after the travel main body unit 2 is positioned at the travel origin position, the main control unit 230 transmits a control command to the travel control unit 242 so that the travel motor 80 rotates in a predetermined reverse direction to move the travel main body unit 2 backward a predetermined distance. When the travel main body unit 2 has moved backward a predetermined distance, the main control unit 230 transmits a stop command for the travel motor 80 to the travel control unit 242. When the travel motor 80 stops in accordance with this stop command, the position in the front-rear direction where the travel main body unit 2 is located is the travel standby position of the travel main body unit 2. When the positioning operation to the travel standby position is completed, the main control unit 230 stores travel standby position information indicating the travel standby position relative to the travel origin position in the work memory 234.

The printing origin detection operation is executed (S3). Specifically, the main control unit 230 sends a control command to the carriage control unit 244 so that the carriage motor 120 rotates in a predetermined reverse direction to move the carriage 102 to the right. While the timing sensor 220 generates a pulse signal in accordance with the rightward movement of the carriage 102, the carriage control unit 244 causes the carriage motor 120 to continue rotating in the predetermined reverse direction so that the carriage 102 moves to the right. When the carriage 102 moves to a predetermined position at the right end of the timing fence 222 where no slit is formed and the timing sensor 220 stops generating a pulse signal, the main control unit 230 sends a stop command for the carriage motor 120 to the carriage control unit 244. The position in the left-right direction where the carriage 102 is located at the time when the carriage motor 120 stops in accordance with this stop command is the printing origin position of the carriage 102.

A positioning operation to the print standby position is performed (S4). In this embodiment, since the print origin position and the print standby position are set to the same position, the main control unit 230 continues to send a stop command for the carriage motor 120 to the carriage control unit 244 until image information, which will be described later, is received. The main control unit 230 stores print standby position information, which indicates the print standby position relative to the print origin position, in the work memory 234.

It is determined whether image information of the specified image size has been received (S5). If it is determined that no image information has been received (S5: NO), the determination process of S5 is repeated. If it is determined that all image information of the specified image size has been received (S5: YES), the main control unit 230 stores all received image information in the working memory 234. The main control unit 230 operates the status display lamp 252 to be continuously lit or flashing depending on the reception status of the image information.

If it is determined that image information has been received (S5: YES), a travel operation to the print start position is executed (S6). The main control unit 230 calculates the print start position relative to the travel origin position based on the image sizes of all the received image information, and stores it in the work memory 234. The main control unit 230 sends a control command to the travel control unit 242 so that the travel motor 80 rotates in a predetermined forward direction to move the travel main body unit 2 forward from the travel standby position to the print start position. While the travel main body unit 2 is moving forward toward the print start position, the travel control unit 242 can recognize the current travel position of the travel main body unit 2 relative to the travel origin position based on the number of pulses of the pulse signal from the photosensor 204 of the encoder 200. When the current travel position of the travel main body unit 2 reaches the print start position, the main control unit 230 sends a stop command to the travel control unit 242 for the travel motor 80. This stop command positions the travel main body unit 2 at the print start position.

A printing operation for one line is executed (S7). Specifically, the main control unit 230 reads out the line printing information for the first line from the image information stored in the work memory 234, and transmits the read-out line printing information to the head control unit 246. In addition, the main control unit 230 transmits a control command to the carriage control unit 244 so that the carriage 102 moves leftward from the print standby position, i.e., moves forward, in order to print the first line from the right side to the left side when the traveling main body unit 2 is stopped at the print start position. While the carriage 102 is moving left and right, the carriage control unit 244 can recognize the current movement position of the carriage 102 relative to the print origin position based on the number of pulses of the pulse signal from the photosensor of the timing sensor 220. The head control unit 246 operates the inkjet heads 112A and 114A when the current movement position of the carriage 102 reaches a predetermined print position.

After the carriage 102 makes its outward movement to print the first line, the main control unit 230 sends a control command to the carriage control unit 244 to move the carriage 102 to the right toward the print standby position, i.e., to make a return movement. When the carriage 102 reaches the print standby position, the main control unit 230 sends a command to the carriage control unit 244 to stop the carriage motor 120.

The traveling operation to the next line position is executed (S8). Specifically, the main control unit 230 sends a control command to the traveling control unit 242 so that the traveling motor 80 rotates in a predetermined reverse direction to move the traveling main body unit 2 to the next line position that is a predetermined line interval away from the print start position. When the traveling main body unit 2 has moved backward by the predetermined line interval, the main control unit 230 sends a stop command for the traveling motor 80 to the traveling control unit 242. When the traveling motor 80 stops in accordance with this stop command, the traveling main body unit 2 is positioned at the next line position. Since the first line has already been printed, the traveling main body unit 2 is positioned at the second line position as the next line position.

The printing operation for the next line is executed (S9). Specifically, the main control unit 230 reads the next line printing information from the image information stored in the work memory 234, and transmits the read line printing information to the head control unit 246. The main control unit 230 also transmits a control command to the carriage control unit 244 to cause the carriage 102 to move leftward from the print standby position, i.e., to perform forward movement, in order to print the next line from the right side to the left side. After the carriage 102 performs the forward movement in order to print the next line, the main control unit 230 transmits a control command to the carriage control unit 244 to cause the carriage 102 to move rightward toward the print standby position, i.e., to perform return movement. When the carriage 102 reaches the print standby position, the main control unit 230 transmits a command to stop the carriage motor 120 to the carriage control unit 244.

It is determined whether the printing operation of all lines has been completed (S10). If the printing operation of all lines has not been completed (S10: NO), the process returns to S8 and is executed. In the re-processing of S8, a travel operation is executed to the position of the line next to the line printed by the processing of S9. If the printing operation of all lines has been completed (S10: YES), the process proceeds to processing of S11. The determination of whether the printing operation of all lines has been completed may be executed, for example, based on whether the last line printing information of the image information stored in the work memory 234 has been read out.

A positioning operation to the print standby position is executed (S11). Specifically, the main control unit 230 sends a control command to the carriage control unit 24 so that the current movement position of the carriage 102 becomes a position according to the print standby position information stored in the work memory 234. When the current movement position of the carriage 102 reaches the print standby position, the main control unit 230 sends a command to stop the carriage motor 120 to the carriage control unit 244. In accordance with this stop command, when all printing operations have ended, the positioning operation of the carriage 102 to the print standby position is completed.

A positioning operation to the travel standby position is executed (S12). Specifically, the main control unit 230 sends a control command to the travel control unit 242 so that the current travel position of the travel main body unit 2 becomes a position according to the travel standby position information stored in the work memory 234. When the current travel position of the travel main body unit 2 reaches the travel standby position, the main control unit 230 sends a stop command for the travel motor 80 to the travel control unit 242. In accordance with this stop command, when all printing operations are completed, the positioning operation of the travel main body unit 2 to the travel standby position is completed.

After the process of S12 is completed, the image information storage area of the working memory 234 is cleared, and the process returns to the process of S5. By executing the process of S5 again, it is determined whether image information for repairing another scratch has been received from the personal computer 300.

Effect of the embodiment
In this embodiment, since the user can detach the traveling main body unit 2 from the guide rail 3 and transport it, maintenance and inspection of the traveling main body unit 2 can be easily performed compared to when the traveling main body unit 2 and the guide rail 3 are integrally configured. In addition, the user can accurately and easily install the guide rail 3 around the printing area where scratches or the like are present, which simplifies the preparation work before printing.

In this embodiment, both ends of the running main body 2 are supported at three points by three wheels 32, 34, and 36. The first wheel 32 and the second wheel 34 fit into the guide grooves of the guide rail 3, while only one third wheel 36 is in direct contact with the floor surface, which is the upper surface 4A of the floor 4. As a result, compared to when both ends of the running main body are supported at four points by four wheels and two wheels at one end are in contact with the floor surface, even if the floor surface is not flat but deformed in a wavy manner, the one third wheel 36 in this embodiment accurately contacts the wavy floor surface, so the running main body 2 can run in a stable posture without vibrating in the vertical direction.

In this embodiment, the first wheel 32 and the second wheel 34 run while fitting into the guide groove of one guide rail 3, and the third wheel 36 runs in contact with the upper surface 4A of the floor 4 without being guided by the guide rail. As a result, compared to a configuration in which the wheels run along two guide rails, there is no need for structural precision such as the parallelism of the two guide rails, and the running main body 2 can run with a simple configuration. In addition, since there is only one guide rail 3, the running printing assembly 1 including the guide rail 3 is easy to transport, and the work of installing the guide rail 3 around the location where a scratch is present on the upper surface 4A of the floor 4 is also easy.

In this embodiment, as shown in Fig. 3, since the third axis AX3 is located between the first axis AX1 and the second axis AX2, the running resistance at the left end of the main body frame 30 can be reduced compared to a configuration in which the third axis AX3 is located at a position outside the range between the first axis AX1 and the second axis AX2. That is, the inventor changed the position of the third axis AX3 to many different positions in the front-rear direction and conducted an experiment on the error between the spacing of the lines printed at the right end of the main body frame 30 and the spacing of the lines printed at the left end of the main body frame 30 at each changed position of the third axis AX3. According to the results of this experiment, the error in a configuration in which the third axis AX3 is located between the first axis AX1 and the second axis AX2 is smaller than the error in a configuration in which the third axis AX3 is located outside the range between the first axis AX1 and the second axis AX2, for example, behind the first axis AX1 or in front of the second axis AX2. From the results of this experiment, it can be seen that the configuration in which the third axis AX3 is located between the first axis AX1 and the second axis AX2 reduces the running resistance at the left end of the main frame 30.

In this embodiment, of the two wheels 32, 34 that fit into the guide groove of one guide rail 3, only the first wheel 32 is driven to rotate by the travel motor 80, and the second wheel 34 rotates in response to the travel of the travel main body 2. This simplifies the overall configuration of the wheel drive mechanism in the mechanical coupling configuration and rotation control configuration compared to a configuration in which a rotational force is applied to both the first wheel and the second wheel. In addition, since the second wheel 34 to which no rotational force is applied can rotate freely, when the travel main body 2 is attached to the guide rail 3, the toothed portion of the second wheel 34 can be reliably engaged with the toothed portion of the toothed belt 18 of the guide rail 3, making it easy to attach the travel main body 2 to the guide rail 3.

In this embodiment, when the running main body 2 runs in the second running direction, which is the direction from the front to the rear, the second wheel 34 and the third wheel 36 rotate following the running caused by the rotation of the first wheel 32 to which a rotational force is applied, so that the direction and amount of running caused by the following rotation of the second wheel 34 and the third wheel 36 can be stabilized compared to when the running main body 2 runs in the first running direction, which is the direction from the rear to the front. In this embodiment, when the main control unit 230 and the running control unit 242 control the drive of the running motor 80 so that the running main body 2 runs in the second running direction in which the running caused by the following rotation of the second wheel 34 and the third wheel 36 is stable, the inkjet heads 112A and 114A execute a printing operation, so that the inkjet heads 112A and 114A can print at a predetermined position in the second running direction with high precision.

In this embodiment, the first wheel 32 and the second wheel 34 are made of a metal material and support the right end of the running main body 2, and the third wheel 36 is made of an elastic material such as rubber and supports the left end of the running main body 2. As a result, even if the left end of the running main body 2 vibrates when the third wheel 36 comes into contact with the upper surface 4A of the floor 4 and rotates, the vibration can be reduced by the elastic material of the third wheel 36. In addition, because the entire third wheel 36 is made of an elastic material such as rubber, the vibration generated at the left end of the running main body 2 can be further reduced.

In this embodiment, the diameter of the third wheel 36 is set to a diameter larger than the diameters of the first wheel 32 and the second wheel 34. As a result, while the running main body unit 2 is running, the third wheel 36 can rotate at a lower rotation speed than the first wheel 32 and the second wheel 34, and vibrations generated at the left end of the main body frame 2 due to the rotation state of the third wheel 36, which varies due to friction resistance between the fixed shaft 76 and the upper surface 4A of the floor 4 and the third wheel 36, can be reduced. In addition, by setting the diameter of the third wheel 36 to a diameter larger than the diameters of the first wheel 32 and the second wheel 34, vibrations generated in the third wheel 36 itself during the running of the running main body unit 2 can be reduced compared to a configuration in which the diameter of the third wheel 36 is set to a diameter smaller than the diameters of both wheels 32 and 34.

In this embodiment, the third axis AX3 of the third wheel 36 is located at the center between the first axis AX1 of the first wheel 32 and the second axis AX2 of the second wheel 34. As shown in FIG. 3, most of the wheel drive mechanism 38 is disposed in the area between the first axis AX1 and the third axis AX3, and the carriage support mechanism 104, which is long in the left-right direction, is disposed in the area between the third axis AX3 and the second axis AX2. As a result, the weight balance of the running main body 2 can be achieved based on the third axis AX3, and the running of the running main body 2 can be stabilized.

In this embodiment, the wheel support frame portion 52 rotatably supports the first wheel 32 and the second wheel 34. The wheel support frame portion 52 includes a mounting plate portion 54 on which the battery 60 is placed. As a result, when the battery 60 is placed on the mounting plate portion 54, the first wheel 32 and the second wheel 34 can be pressed against the guide rail 3 with a large force due to the weight of the battery 60, and the toothed portions formed on the circumferential portions of the first wheel 32 and the second wheel 34 can be reliably engaged with the toothed portion of the toothed belt 18 of the guide rail 3, allowing the running main body portion 2 to run with high precision.

In this embodiment, a pair of side portions 32A, 32B of the first wheel 32 and a pair of side portions 34A, 34B of the second wheel 34 contact a pair of guide walls 14, 16 of the guide rail 3, respectively. As a result, the first wheel 32 and the second wheel 34 can run straight along the guide rail 3 without meandering, and the running main body 2 can run straight even without guiding the third wheel 36 with a guide rail or the like.

In this embodiment, the rotating shaft 62 of the first wheel 32 is rotatably supported by a pair of bearings 64, 66, and the rotating shaft 68 of the second wheel 34 is rotatably supported by a pair of bearings 70, 72. The third wheel 36 is rotatably supported by the fixed shaft 76 fixed to the left support plate portion 50 of the main body frame 30 by fitting the through hole 74 of the third wheel 36 into the fixed shaft 76. As a result, the third wheel 36 rotates in direct contact with the fixed shaft 76 through the through hole 74, so that compared to a configuration in which the third wheel 36 is supported by a bearing, the third wheel 36 always rotates while receiving slight contact resistance due to contact with the fixed shaft 76, and it is possible to reduce disturbance of the running posture at the left end of the main body frame 30 due to the inertial force acting on the third wheel 36 when the third wheel 36 rotates or stops.

In this embodiment, the main control unit 230, the travel control unit 242, the carriage control unit 244, and the head control unit 246 execute line printing control processes S7 and S9 to cause the inkjet heads 112A and 114A to print one line extending in the left-right direction, and execute a travel control process S8 to drive the travel motor 80 so that the travel main body unit 2 travels a predetermined line interval in the second travel direction, which is the direction from front to rear, after the line printing control processes S7 and S9 are executed. As a result, the travel control process S8 is executed after the line printing control processes S7 and S9 are executed, so that the fluctuation of the printing position on the upper surface 4A of the floor 4 due to the travel operation of the travel main body unit 2 can be reduced.

<Configuration Correspondence>
The running printing assembly 1 or the running main body 2 is an example of the printing device of the present invention. The guide rail 3 is an example of the guide rail of the present invention. The upper surface 4A of the floor 4 is an example of the surface on which the printing area of the present invention is located. The guide bottom 12 and the pair of guide wall portions 14, 16 are an example of the bottom surface portion of the guide rail of the present invention and the pair of guide wall portions. The guide groove formed by the guide bottom 12 and the pair of guide wall portions 14, 16 is an example of the guide groove of the present invention. The toothed portion formed on the circumferential portion of each wheel of the first wheel 32 and the second wheel 34 is an example of the wheel uneven portion of the present invention. The toothed portion of the toothed belt 18 is an example of the guide uneven portion of the present invention. The main body frame 30 is an example of the device frame of the present invention. The first wheel 32, the second wheel 34, and the third wheel 36 are an example of the first wheel, the second wheel, and the third wheel of the present invention. The side portions 32A, 32B of the first wheel 32 and the side portions 34A, 34B of the second wheel 34 are an example of a pair of side portions of the first wheel and the second wheel of the present invention. The wheel drive mechanism 38 is an example of a wheel drive mechanism of the present invention. The printing unit 40 is an example of a printing unit of the present invention. The combination of the left support plate portion 50 and the fixed shaft 76 is an example of a second support portion of the present invention. The combination of the wheel support frame portion 52, the rotating shafts 62, 68, and the bearings 64, 66, 70, 72 is an example of a first support portion of the present invention. The wheel support frame portion 52, the mounting plate portion 54, and the battery 60 are an example of a support frame, a mounting plate portion, and a battery of the present invention. The through hole 74 of the third wheel 36 is an example of a hole of the third wheel of the present invention. The travel motor 80 is an example of a drive motor that imparts a rotational force to the first wheel of the present invention. The travel transmission mechanism 82 is an example of a transmission mechanism that transmits the rotational force of the drive motor to the first wheel of the present invention. The carriage 102 and the carriage support mechanism 104 are an example of the carriage and the carriage support mechanism of the present invention. The upper support rail 108 and the lower support rail 110 are an example of the support rail of the present invention. The inkjet heads 114A, 116A and the ink containers of the cartridges 114, 116 are an example of the inkjet head and the ink container of the present invention. The combination of the main control unit 230, the travel control unit 242, the carriage control unit 244 and the head control unit 246 is an example of the control unit of the present invention. The first axis AX1, the second axis AX2 and the third axis AX3 are an example of the first axis, the second axis and the third axis of the present invention. The front-rear direction is an example of the predetermined travel direction of the present invention, and the front direction and the rear direction are an example of the first travel direction and the second travel direction of the present invention. The left-right direction is an example of the orthogonal direction of the present invention. The processes of S7 and S9 are an example of the line printing control process of the present invention, and the process of S8 is an example of the travel control process of the present invention.

[Modification]
The present invention is not limited to the present embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. An example of such a modification will be described below.

(1) In this embodiment, one guide rail 3 is used, but the present invention is not limited to this guide rail 3. As long as multiple guide rail sections can be freely connected, the number of connected guide rail sections can be changed according to the width of the printing area, and the multiple connected guide rail sections can be assembled into a single guide rail. This modification allows the use of shorter guide rail sections rather than longer guide rails, making the guide rail easier to carry and transport.

(2) In this embodiment, the toothed portions formed on the circumferential portions of the first wheel 32 and the second wheel 34 mesh with the toothed portions of the toothed belt 18 of the guide rail 3, but this is not limited to the configuration. For example, a sprocket formed on the circumferential portion of each wheel may engage with a chain disposed on the guide bottom of the guide rail.

(3) In this embodiment, the entire third wheel 36 is molded from urethane rubber, but is not limited to this urethane rubber. For example, other types of rubber can be used as long as they have an elastic force that can minimize elastic deformation of the third wheel 36 while the third wheel 36 is rotating and the running main body 2 is running, and can reduce vibrations generated in the running main body 2 while running. For example, silicone rubber, butadiene rubber, synthetic natural rubber, etc. can also be used.

(4) In this embodiment, the first wheel 32 and the second wheel 34 are formed from a metal material such as aluminum, but are not limited to this metal material. For example, a hard synthetic resin material such as polyacetal may be used as the material for each wheel.

(5) In this embodiment, each of cartridges 114 and 116 has a configuration in which the inkjet head and the ink container are integrated, but the configuration of each cartridge is not limited to an integrated configuration. For example, the ink container may be configured independently of the inkjet head and configured to be replaceable on its own.

(6) In this embodiment, color image information for repairing scratches on the upper surface 4A of the floor 4 is created in advance by the personal computer 300 based on the color and pattern of the upper surface 4A, but this is not limited to the configuration. For example, a configuration in which the traveling main body unit is equipped with a scanner that scans the upper surface 4A is conceivable. In this modified example, the user installs a guide rail around the location where the scratch exists, and the scanner of the traveling main body unit attached to the guide rail scans the area around the location where the scratch exists. This scanned image information is sent to the personal computer, and the personal computer processes the image so that it is suitable for color printing. The traveling main body unit executes a printing operation according to the image information that has been processed. In another modified example, the traveling main body unit may be equipped with a function for image processing by a personal computer.

(7) In this embodiment, the print origin position and print standby position of the carriage 102 are set to positions close to the positions of the first wheel 32 and the second wheel 34, but this is not limited to the configuration. For example, the print origin position and print standby position of the carriage 102 may be set to positions close to the position of the third wheel 36.

(8) In this embodiment, the print start position is set at a position away from the travel origin position and travel standby position of the traveling main body unit 2, separated by the printing area where the image information is printed, but is not limited to this configuration. For example, the print start position may be set at a position close to the travel origin position and travel standby position of the traveling main body unit 2. In this modified example, since the printing operation is performed while traveling in the direction from the first wheel to the second wheel, it is preferable that the wheel to which the rotational force is applied is the second wheel, rather than the first wheel.

(9) In this embodiment, the guide rail 3 is installed on the upper surface 4A of the floor 4, which is the surface on which the printing area is located, but this configuration is not limited to this. For example, when printing a desired pattern on clothing such as a T-shirt, the holding surface of the holding device on which the clothing is placed and held and the installation surface of the installation table on which the guide rail is installed may be arranged at different heights. In this modified example, the holding surface and the installation surface do not need to be strictly parallel, as long as they are parallel to each other without interfering with printing on the clothing.

(10) In this embodiment, of the first wheel 32 and the second wheel 34, the first wheel 32 is configured to be rotated and driven by the travel motor 80, but this is not limited to the configuration. For example, the first wheel and the second wheel may be configured to be connected to two separate travel motors, respectively. Also, the first wheel, which is rotated and driven by one travel motor, may be configured to be connected to the second wheel via a timing belt or a gear train.

(11) In this embodiment, in order to support the right end of the running main body 2, one first wheel 32 that is driven to rotate and one second wheel 34 that rotates in response are provided, but this configuration is not limited to this. For example, a configuration in which multiple wheels are arranged in a row as the second wheel that rotates in response to the first wheel may also be used.

1 Traveling printing assembly 2 Traveling main body 3 Guide rail 4 Floor 4A Upper surface of floor 4 12 Guide bottom 14, 16 Pair of guide wall portions 18 Toothed belt 30 Main body frame 32, 34, 36 First wheel, second wheel, third wheel 32A, 32B Side portion 34A, 34B of first wheel 32 Side portion 38 of second wheel 34 Wheel drive mechanism 40 Printing unit 50 Left support plate portion 52 Wheel support frame portion 54 Placement plate portion 60 Battery 62, 68 Rotating shaft 64, 66, 70, 72 Bearing 74 Through hole 76 of third wheel 36 Fixed shaft 80 Traveling motor 82 Traveling transmission mechanism 102 Carriage 104 Carriage support mechanism 108, 110 Upper support rail, lower support rail 114A, 116A Inkjet head 230 Main control unit 242, 244, 246 Travel control unit, carriage control unit, head control unit AX1, AX2, AX3 First axis, second axis, third axis

Claims (11)

A printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to said surface and prints on the printing area,
An apparatus frame extending in a direction perpendicular to a predetermined traveling direction;
a first support portion disposed at one end of the device frame in the perpendicular direction and supporting the first wheel and the second wheel rotatably about a first axis and a second axis extending in the perpendicular direction, respectively;
a second support portion disposed at the other end portion opposite to the one end portion of the device frame in the perpendicular direction, and supporting one third wheel rotatably around a third axis line extending in the perpendicular direction;
a printing unit disposed inside the device frame and configured to print on the printing area in the orthogonal direction;
a wheel drive mechanism disposed inside the device frame and configured to apply a rotational force to at least one of the first wheel and the second wheel;
the first support portion supports the first wheel and the second wheel such that the first wheel and the second wheel are arranged in a line with a gap therebetween in a predetermined traveling direction;
the second support portion supports the third wheel such that the third axis is located between the first axis and the second axis;
a guide groove of a single guide rail installed on a surface on which the printing area is located or on a surface parallel to said surface, the guide groove extending in a predetermined traveling direction, the wheel widths of the first wheel and the second wheel being determined so that the first wheel and the second wheel are fitted into the guide groove;
A printing device in which, when the first wheel and the second wheel are fitted into the guide groove and run, the third wheel runs in contact with a surface on which a printing area is located or a surface parallel to that surface. A printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to said surface and prints on the printing area,
An apparatus frame extending in a direction perpendicular to a predetermined traveling direction;
a first support portion disposed at one end of the device frame in the perpendicular direction and supporting the first wheel and the second wheel rotatably about a first axis and a second axis extending in the perpendicular direction, respectively;
a second support portion disposed at the other end portion opposite to the one end portion of the device frame in the perpendicular direction, and supporting one third wheel rotatably around a third axis line extending in the perpendicular direction;
a printing unit disposed inside the device frame and configured to print on the printing area in the orthogonal direction;
a wheel drive mechanism disposed inside the device frame and configured to apply a rotational force to one of the first wheel and the second wheel;
A guide rail having a guide groove extending in a predetermined traveling direction, the guide rail being installed on a surface on which the printing area is located or on a surface parallel to the surface;
the first support portion supports the first wheel and the second wheel such that the first wheel and the second wheel are arranged in a line with a gap therebetween in a predetermined traveling direction;
the second support portion supports the third wheel such that the third axis is located between the first axis and the second axis;
a wheel width of each of the first wheel and the second wheel is determined so that the first wheel and the second wheel are fitted into a guide groove of the guide rail,
The wheel unevenness portion is formed over the entire circumferential surface of each of the first wheel and the second wheel, and the guide unevenness portion is formed over the entire bottom surface of the guide groove so as to mesh with the wheel unevenness portion of each of the wheels;
A printing device in which, when the first wheel and the second wheel are fitted into the guide groove and run, the third wheel runs in contact with a surface on which a printing area is located or a surface parallel to that surface. Each of the first wheel and the second wheel is made of a metal material;
3. The printing device according to claim 1, wherein the third wheel is made of a material having a greater elasticity than the first wheel and the second wheel. the first support portion includes a rotation shaft to which each of the first wheel and the second wheel is fixed, and a bearing that rotatably supports the rotation shaft;
The second support portion includes a fixed shaft fixed to the device frame,
4. The printing device according to claim 1, wherein the third wheel has a circular hole through which the fixed shaft is inserted. The diameter of the first wheel is set to be the same as the diameter of the second wheel;
5. The printing device according to claim 1, wherein the diameter of the third wheel is set to be larger than the diameter of the first wheel. A printing device according to any one of claims 1 to 5, wherein the third axis of the third wheel is disposed at a central position between the first axis of the first wheel and the second axis of the second wheel. The wheel drive mechanism includes a drive motor that imparts a rotational force to the first wheel, and a transmission mechanism that transmits the rotational force of the drive motor to the first wheel,
The printing unit is
a carriage carrying an inkjet head and an ink container;
a carriage support mechanism having support rails extending in the perpendicular direction and supporting the carriage so as to be capable of reciprocating along the support rails;
the drive motor is supported by the device frame so as to be located between the first axis of the first wheel and the third axis of the third wheel;
7. The printing apparatus according to claim 1, wherein the support rail is supported by the apparatus frame so as to be located between the second axis of the second wheel and the third axis of the third wheel. the first support portion includes a rotating shaft to which the first wheel and the second wheel are fixed, a pair of bearings that rotatably support both ends of the rotating shaft, and a support frame to which the pair of bearings are attached;
8. The printing apparatus according to claim 1, wherein the support frame has a mounting plate portion on which a battery for supplying power to the printing unit and the wheel drive mechanism is mounted. Each of the first wheel and the second wheel includes a circumferential portion and a pair of side portions located on either side of the circumferential portion,
The guide rail includes a bottom surface portion and a pair of guide wall portions standing on both side ends of the bottom surface portion, and the bottom surface portion and the pair of guide wall portions form a guide groove,
9. The printing device according to claim 1, wherein a pair of side surfaces of each wheel contact a pair of guide wall portions, respectively. A printing device that travels in a predetermined traveling direction on a surface on which a printing area is located or on a surface parallel to said surface and prints on the printing area,
An apparatus frame extending in a direction perpendicular to a predetermined traveling direction;
a first support portion disposed at one end of the device frame in the perpendicular direction and supporting the first wheel and the second wheel rotatably about a first axis and a second axis extending in the perpendicular direction, respectively;
a second support portion disposed at the other end portion opposite to the one end portion of the device frame in the perpendicular direction, and supporting one third wheel rotatably around a third axis line extending in the perpendicular direction;
a printing unit disposed inside the device frame and configured to print on the printing area in the orthogonal direction;
a wheel drive mechanism disposed inside the device frame and configured to apply a rotational force to the first wheel;
a control unit for controlling the operation of the printing unit and the wheel drive mechanism;
the first support portion supports the first wheel and the second wheel such that the first wheel and the second wheel are arranged in a line with a gap therebetween in a predetermined traveling direction;
the second support portion supports the third wheel such that the third axis is located between the first axis and the second axis;
a guide groove of a single guide rail installed on a surface on which the printing area is located or on a surface parallel to said surface, the guide groove extending in a predetermined traveling direction, the wheel widths of the first wheel and the second wheel being determined so that the first wheel and the second wheel are fitted into the guide groove;
When the first wheel and the second wheel are fitted in the guide groove and run, the third wheel runs in contact with a surface on which the printing area is located or a surface parallel to that surface,
A printing device in which the control unit causes the printing unit to stop a printing operation when the control unit controls the operation of the wheel drive mechanism so that the printing device travels in a first running direction from the first wheel to the second wheel among specified running directions, and causes the printing unit to perform a printing operation when the control unit controls the operation of the wheel drive mechanism so that the printing device travels in a second running direction from the second wheel to the first wheel. The printing device according to claim 10, wherein the control unit executes a line printing control process that causes the printing unit to execute a printing operation of one line extending in an orthogonal direction, and a travel control process that causes the wheel drive mechanism to execute a travel operation so that the printing device travels a predetermined line interval in a second travel direction from the second wheel toward the first wheel after the line printing control process is executed.

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