Printing system

Abstract

To provide a printing system provided with a printing device that performs printing on a medium, an unprinted-medium arrangement part in which an unprinted medium is arranged and a conveying robot that conveys the medium from the unprinted-medium arrangement part to the printing device, in which a hand of the conveying robot stops when there is no medium in the unprinted-medium arrangement part.SOLUTION: A printing system 1 is provided with a printing device 3 that performs printing on a medium 2; an unprinted-medium arrangement part 4 in which an unprinted medium 2 is arranged; and a conveying robot 6 that conveys the medium 2 from the unprinted-medium arrangement part 4 to the printing device 3. The conveying robot 6 is provided with a hand 21 for holding the medium 2. A medium sensing mechanism for sensing presence or absence of the medium 2 in the unprinted-medium arrangement part 4 is mounted on the hand 21. When the medium sensing mechanism senses that the medium 2 is not arranged in the unprinted-medium arrangement part 4, the hand 21 stops instantly.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a printing system that includes a printing device that prints on a medium and a transport robot that transports the medium. [Background technology]

[0002] Conventionally, there is known a printing system that performs printing on a semiconductor substrate (see, for example, Patent Document 1). The printing system described in Patent Document 1 includes an inkjet printer (coating section) that performs printing by ejecting droplets onto a semiconductor substrate, a transport robot (transport section) that transports the semiconductor substrate in the printing system, and a cooling section that cools the semiconductor substrate before it is carried into the inkjet printer. The transport robot is a SCARA type robot that includes an arm having two arms and a hand (gripping section) attached to the tip side of the arm. The transport robot transports the semiconductor substrate from the cooling section to the inkjet printer, for example. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-183595 A Summary of the Invention [Problem to be solved by the invention]

[0004] The printing system described in Patent Document 1 does not propose a specific operation of the transport robot when the semiconductor substrate to be carried into the inkjet printer is not in the cooling unit. Also, the printing system described in Patent Document 1 does not propose a specific operation of the transport robot when the hand fails to hold the semiconductor substrate in the cooling unit.

[0005] Therefore, a first object of the present invention is to propose a specific operation of the transport robot when there is no medium in the pre-printing medium placement unit in a printing system including a printing device that prints on a medium, a pre-printing medium placement unit where the pre-printing medium is placed, and a transport robot that transports the medium from the pre-printing medium placement unit to the printing device.A second object of the present invention is to propose a specific operation of the transport robot when there is no medium in the pre-printing medium placement unit in a printing system including a printing device that prints on a medium, a pre-printing medium placement unit where the pre-printing medium is placed, and a transport robot that transports the medium from the pre-printing medium placement unit to the printing device, when a hand fails to hold the medium in the pre-printing medium placement unit. [Means for solving the problem]

[0006] In order to solve the first problem above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-print media placement section to the printing device, the transport robot comprising a hand that holds the medium and a media detection mechanism for detecting the presence or absence of the medium in the pre-print media placement section, the media detection mechanism being attached to the hand, and when the media detection mechanism detects that the medium is not placed in the pre-print media placement section, the hand stops at the position where it was positioned at the time it was detected that the medium was not placed.

[0007] In the printing system of the present invention, when the medium detection mechanism attached to the hand detects that no medium is placed in the pre-printing medium placement section, the hand stops at the position where it was placed at the time when it was detected that no medium was placed. Therefore, in the present invention, the operator can visually check the position of the stopped hand and the situation around the hand, and intuitively recognize that the transport robot has stopped due to the absence of media in the pre-printing medium placement section. Therefore, in the present invention, the operator can easily understand the reason why the transport robot has stopped.

[0008] In addition, in order to solve the first problem above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-print media placement section to the printing device, and the transport robot comprises a hand that holds the medium and a media detection mechanism for detecting the presence or absence of the medium in the pre-print media placement section, the media detection mechanism being attached to the hand, and when the media detection mechanism detects that no medium is placed in the pre-print media placement section, the hand moves to a predetermined position and then stops.

[0009] In the printing system of the present invention, when the media detection mechanism attached to the hand detects that no media is placed in the pre-printing media placement section, the hand moves to a predetermined position and then stops. Therefore, in the present invention, when it is detected that no media is placed in the pre-printing media placement section, it is possible to move and stop the hand to a position that is less likely to interfere with the operator's work of placing media in the pre-printing media placement section. Therefore, in the present invention, it is possible for the operator to easily perform the work of placing media in the pre-printing media placement section that has run out of media.

[0010] In the present invention, for example, when the media detection mechanism detects that no media is placed in the pre-printing media placement section, the hand moves to a fixed position, which is the position of the hand when the transport robot starts the media transport operation, and then stops. In this case, by setting the position of the hand that is least likely to interfere with the operator's work of placing media in the pre-printing media placement section as the fixed position, it becomes possible for the operator to easily place media in the pre-printing media placement section when there is no media left.

[0011] In the present invention, for example, when the media detection mechanism detects that no media is placed in the pre-printing media placement section, the hand may move upward a predetermined amount in the pre-printing media placement section and then stop. In this case, when the media detection mechanism detects that no media is placed in the pre-printing media placement section, the hand is raised to a position where the operator's work to place the media in the pre-printing media placement section is not likely to be hindered and stopped, making it easier for the operator to place the media in the pre-printing media placement section where the media has run out. Also, in this case, since the hand is raised and stopped in the pre-printing media placement section, when the transport robot is operated after placing the media in the pre-printing media placement section, it is possible for the hand to hold the media in the pre-printing media placement section in a short time.

[0012] Furthermore, in order to solve the first problem above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-print media placement section to the printing device, the transport robot comprising a hand that holds the medium and a robot control unit that controls the transport robot, and the pre-print media placement section is capable of placing multiple media, the robot control unit retains information on the current number of media being placed in the pre-print media placement section, and checks the current number of media being placed in the pre-print media placement section when the transport robot begins the operation of transporting the media from the pre-print media placement section to the printing device, and if the current number of media confirmed by the robot control unit is 0, the hand stops at a fixed position which is the position of the hand when the transport robot begins the operation of transporting the media.

[0013] In the printing system of the present invention, the robot control unit holds information on the current number of sheets of media to be placed in the pre-printing medium placement unit, and checks the current number of sheets of media to be placed in the pre-printing medium placement unit when the transport robot starts the transport operation of the media from the pre-printing medium placement unit to the printing device, and if the current number of sheets of media checked by the robot control unit is 0, the hand stops at a fixed position, which is the position of the hand when the transport robot starts the transport operation of the media. Therefore, in the present invention, by setting the position of the hand that is less likely to cause interference with the work of the operator to place the media in the pre-printing medium placement unit as the fixed position, when the current number of sheets of media checked by the robot control unit is 0, it is possible to stop the hand at a position that is less likely to cause interference with the work of the operator to place the media in the pre-printing medium placement unit. Therefore, in the present invention, it is possible to easily perform the work of the operator to place the media in the pre-printing medium placement unit when the media has run out.

[0014] Furthermore, in order to solve the first problem above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-print media placement section to the printing device, wherein the transport robot has a hand that holds the medium, and the pre-print media placement section has a media detection mechanism for detecting the presence or absence of media, and when the media detection mechanism detects that no media is placed in the pre-print media placement section when the transport robot begins the operation of transporting the medium from the pre-print media placement section to the printing device, the hand stops at a fixed position which is the position of the hand when the transport robot begins the operation of transporting the medium.

[0015] In the printing system of the present invention, when the transport robot starts the operation of transporting the medium from the pre-printing medium placement section to the printing device and the media detection mechanism detects that no medium is placed on the pre-printing medium placement section, the hand stops at a fixed position, which is the position of the hand when the transport robot starts the operation of transporting the medium. Therefore, in the present invention, by setting the position of the hand at a fixed position that is unlikely to interfere with the work of the operator to place the medium on the pre-printing medium placement section, when the media detection mechanism detects that no medium is placed on the pre-printing medium placement section, it is possible to stop the hand at a position that is unlikely to interfere with the work of the operator to place the medium on the pre-printing medium placement section. Therefore, in the present invention, it is possible to easily perform the work of the operator to place the medium on the pre-printing medium placement section when the medium has run out.

[0016] In the present invention, for example, when the hand stops and a medium is placed on the pre-printing medium placement section, the printing device resets the count value of the number of sheets of medium printed by the printing device. Also, in the present invention, for example, when the hand stops and a medium is placed on the pre-printing medium placement section, the printing device may continue counting the number of sheets of medium printed by the printing device without resetting the count value of the number of sheets of medium printed by the printing device.

[0017] In addition, in order to solve the second problem described above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media positioning section where the medium is positioned before printing, and a transport robot that transports the medium from the pre-print media positioning section to the printing device, wherein the transport robot has a hand that holds the medium, and the transport robot or the pre-print media positioning section has a media holding detection mechanism for detecting that the hand is holding the medium in the pre-print media positioning section, and when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-print media positioning section, the hand stops at the position where it was positioned at the time it was detected that it had failed to hold the medium.

[0018] In the printing system of the present invention, when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-printing medium placement section, the hand stops in the position where it was located at the time the failure to hold the medium was detected. Therefore, in the present invention, the operator can visually check the position of the stopped hand and the situation around the hand, and intuitively recognize that the transport robot has stopped because the hand has failed to hold the medium in the pre-printing medium placement section. Therefore, in the present invention, the operator can easily understand the cause of the transport robot's stop.

[0019] Furthermore, in order to solve the second problem above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-print media positioning section where the medium is positioned before printing, and a transport robot that transports the medium from the pre-print media positioning section to the printing device, wherein the transport robot has a hand that holds the medium, and the transport robot or the pre-print media positioning section has a media holding detection mechanism for detecting that the hand is holding the medium in the pre-print media positioning section, and when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-print media positioning section, the hand moves to a predetermined position and then stops.

[0020] In the printing system of the present invention, when the media hold detection mechanism detects that the hand has failed to hold the medium in the pre-printing medium placement unit, the hand moves to a predetermined position and then stops. Therefore, in the present invention, when it is detected that the hand has failed to hold the medium in the pre-printing medium placement unit, it is possible to move the hand to a position where it is stopped so as not to interfere with the operator's work, such as removing the medium that was not held and maintaining the hand. Therefore, in the present invention, it is possible for the operator to easily perform recovery work when the hand has failed to hold the medium in the pre-printing medium placement unit.

[0021] In the present invention, for example, when the media hold detection mechanism detects that the hand has failed to hold the medium in the pre-printing media placement section, the hand moves to a fixed position, which is the position of the hand when the transport robot starts the medium transport operation, and then stops. In this case, by setting the position of the hand that is least likely to cause interference with operator work such as removing the unheld medium and maintaining the hand as the fixed position, it becomes possible for the operator to easily perform recovery work when the hand has failed to hold the medium in the pre-printing media placement section.

[0022] In the present invention, for example, when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-printing medium placement section, the hand may move a predetermined amount upward in the pre-printing medium placement section and then stop. In this case, when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-printing medium placement section, the hand is raised to a position where it is less likely to interfere with the operator's work, such as removing the unheld medium and maintaining the hand, and then stopped, making it easier for the operator to perform recovery work when the hand has failed to hold the medium in the pre-printing medium placement section. Also, in this case, since the hand is raised and stopped in the pre-printing medium placement section, when the transport robot is restarted after the recovery work is completed, the hand can hold the medium in the pre-printing medium placement section in a short time.

[0023] In the present invention, the printing device preferably includes a table on which the medium is placed, and the fixed position is preferably higher than the top surface of the table and the top end of the pre-printing medium placement section. With this configuration, the hand placed at the fixed position is less likely to interfere with the operator's work in the pre-printing medium placement section. This makes it easier for the operator to place media in the pre-printing medium placement section when the media has run out, and to easily perform recovery work when the hand fails to hold the media in the pre-printing medium placement section.

[0024] In the present invention, for example, the printing device is provided with an emergency stop button for emergency stopping the printing device, and the fixed position is a position higher than the upper end of the emergency stop button. In this case, the hand placed at the fixed position is less likely to interfere with an operator pressing the emergency stop button of the printing device.

[0025] In the present invention, it is preferable that the fixed position is a position different from the printing device and the pre-printing medium placement unit when viewed from above and below. With this configuration, the hand placed at the fixed position is less likely to interfere with the operator's work at the pre-printing medium placement unit. This makes it easier for the operator to place media in the pre-printing medium placement unit when the media has run out, and to easily perform recovery work when the hand fails to hold the media at the pre-printing medium placement unit. Effect of the Invention

[0026] As described above, the printing system of the present invention makes it easier for the operator to understand the cause of the transport robot's stop. Also, the printing system of the present invention makes it easier for the operator to place media in the pre-printing media placement section when the media has run out, and to perform recovery work when the hand in the pre-printing media placement section fails to hold the media. [Brief description of the drawings]

[0027] [Figure 1] 1 is a perspective view of a printing system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a plan view of the printing system shown in FIG. [Diagram 3] FIG. 2 is a side view of the printing system shown in FIG. [Figure 4] FIG. 2 is a block diagram for explaining the configuration of the printing system shown in FIG. [Diagram 5] FIG. 2 is a schematic diagram for explaining the configuration of the printing apparatus shown in FIG. [Figure 6] 4 is a flowchart for explaining the operation of the printing system shown in FIG. [Figure 7] FIG. 13 is a perspective view of a printing system according to another embodiment of the present invention. [Figure 8] FIG. 8 is a plan view of the printing system shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0029] (Overall configuration of the printing system) FIG 1 is a perspective view of a printing system 1 according to an embodiment of the present invention. FIG 2 is a plan view of the printing system 1 shown in FIG 1. FIG 3 is a side view of the printing system 1 shown in FIG 1. FIG 4 is a block diagram for explaining the configuration of the printing system 1 shown in FIG 1. FIG 5 is a schematic diagram for explaining the configuration of the printing device 3 shown in FIG 1.

[0030] The printing system 1 of this embodiment is a system for printing on a medium 2. The printing system 1 includes a printing device 3 that prints on the medium 2, a pre-printed medium placement section 4 where the medium 2 before printing is placed, a printed medium placement section 5 where the medium 2 after printing is placed, a transport robot 6 that transports the medium 2 from the pre-printed medium placement section 4 to the printing device 3 and transports the medium 2 from the printing device 3 to the printed medium placement section 5, and a control device 7 for controlling the printing device 3 and the transport robot 6. The medium 2 is formed in a flat plate shape. Specifically, the medium 2 is formed in a quadrangular flat plate shape. That is, the medium 2 is a quadrangular flat plate shape. The medium 2 of this embodiment is formed in a rectangular or square flat plate shape. Also, the medium 2 is formed of a resin such as an acrylic resin. The control device 7 is, for example, a PC (personal computer).

[0031] The printing device 3 is an inkjet printer for commercial use. Therefore, in the following description, the printing device 3 will be referred to as the "printer 3." As shown in Fig. 5, the printer 3 includes an inkjet head 9 (hereinafter referred to as the "head 9") that ejects ink toward the medium 2, a carriage 10 on which the head 9 is mounted, a carriage drive mechanism 11 that moves the carriage 10 in the main scanning direction (Y direction in Fig. 5, etc.), and a guide rail 12 for guiding the carriage 10 in the main scanning direction. The carriage 10, the carriage drive mechanism 11, and the guide rail 12 are covered by a cover 17.

[0032] The printer 3 also includes a table 13 on which the medium 2 is placed, a table drive mechanism 14 for moving the table 13 in a sub-scanning direction (X direction in FIG. 1, etc.) perpendicular to the main scanning direction and the up-down direction (vertical direction, Z direction in FIG. 1, etc.), a guide mechanism for guiding the table 13 in the sub-scanning direction, an emergency stop button 15 for emergency stopping the printer 3, and a printer control unit 16 for controlling the printer 3. In the following description, the main scanning direction is the left-right direction, and the sub-scanning direction is the front-rear direction. Also, the Y1 direction side in FIG. 1, etc., which is one side of the left-right direction, is the "right" side, the Y2 direction side in FIG. 1, etc., which is the opposite side of the right side, is the "left" side, the X1 direction side in FIG. 1, etc., which is one side of the front-rear direction, is the "front" side, and the X2 direction side in FIG. 1, etc., which is the opposite side of the front side, is the "rear" side.

[0033] The upper surface of the table 13 is a plane perpendicular to the up-down direction. One or more sheets of media 2 are placed on the upper surface of the table 13 depending on the size of the media 2, etc. The carriage 10 is disposed above the table 13. The head 9 ejects ink from above toward the medium 2 placed on the upper surface of the table 13. The carriage drive mechanism 11 includes, for example, a motor, a drive pulley that rotates by the power of the motor, a driven pulley, and a belt that is stretched between the drive pulley and the driven pulley. A portion of the belt is fixed to the carriage 10. The table drive mechanism 14 includes, for example, a motor, a ball screw, etc.

[0034] In this embodiment, the right end side of the printer 3 is the home position of the carriage 10. Also, in this embodiment, when the transport robot 6 transports the medium 2 from the pre-printing medium placement unit 4 to the printer 3, and when the transport robot 6 transports the medium 2 from the printer 3 to the post-printing medium placement unit 5, the table 13 moves to and stops in front of the cover 17 so that the medium 2 transported by the transport robot 6 does not interfere with the cover 17.

[0035] The emergency stop button 15 is located at the front end of the printer 3. The emergency stop button 15 is also located on the right side of the table 13, which has moved forward and stopped. The emergency stop button 15 is electrically connected to the printer control unit 16. An operator of the printing system 1 presses the emergency stop button 15 from above. When the emergency stop button 15 is pressed, the printer 3 is brought to an emergency stop. The upper end of the emergency stop button 15 is located above the top surface of the table 13. The printer control unit 16 is electrically connected to the control device 7.

[0036] The pre-printing medium placement unit 4 is, for example, a table, and the medium 2 before printing by the printer 3 is placed on the pre-printing medium placement unit 4. The pre-printing medium placement unit 4 is disposed in front of the printer 3. The pre-printing medium placement unit 4 is also disposed to the right of the table 13. In other words, the pre-printing medium placement unit 4 is disposed on the home position side of the carriage 10.

[0037] The pre-printing medium placement section 4 is formed with a medium placement surface 4a on which the medium 2 is placed. The medium placement surface 4a is a plane perpendicular to the up-down direction. The height of the medium placement surface 4a is lower than the height of the upper surface of the table 13. The pre-printing medium placement section 4 is capable of placing multiple sheets of medium 2. Specifically, the pre-printing medium placement section 4 is capable of placing multiple sheets of medium 2 in a stacked manner. That is, the pre-printing medium placement section 4 is capable of placing multiple sheets of medium 2 in a stacked manner. The multiple sheets of medium 2 are placed in a stacked manner on the medium placement surface 4a. In this embodiment, an operator of the printing system 1 places multiple sheets of medium 2 on the medium placement surface 4a.

[0038] The pre-print medium placement section 4 is provided with a number of positioning pins 19 for positioning the medium 2 in the horizontal direction. The pre-print medium placement section 4 in this embodiment is provided with three positioning pins 19. The positioning pins 19 are formed in a long, thin cylindrical shape. The three positioning pins 19 rise upward. Specifically, the three positioning pins 19 rise upward from the medium placement surface 4a. In this embodiment, the upper end (upper end surface) of the positioning pins 19 forms the upper end of the pre-print medium placement section 4. The height of the upper end of the positioning pins 19 is lower than the height of the upper surface of the table 13.

[0039] The three positioning pins 19 are disposed at the left rear end of the pre-printing medium placement section 4. Two of the three positioning pins 19 are disposed at the same position in the front-to-rear direction and are disposed with a gap in between in the left-to-right direction. The remaining positioning pin 19 is disposed forward of the two positioning pins 19 and to the left of the two positioning pins 19.

[0040] As described above, the medium 2 is formed in a quadrangular flat plate shape (specifically, a rectangular or square flat plate shape). The end faces of the medium 2 positioned by the three positioning pins 19 are parallel to the front-rear or left-right direction. When the medium 2 is positioned by the three positioning pins 19, the rear end face and the left end face of the medium 2 are in contact with the positioning pins 19. That is, as shown in FIG. 2, if one corner on one diagonal of the medium 2, which is a quadrangular flat plate, is defined as a first corner 2a and the other corner is defined as a second corner 2b, when the medium 2 is positioned by the three positioning pins 19, each of the two end faces of the medium 2 connected to the first corner 2a is in contact with the positioning pin 19.

[0041] The printed medium placement unit 5 is, for example, a wagon, and the medium 2 after printing by the printer 3 is placed on the printed medium placement unit 5. The printed medium placement unit 5 is located in front of the printer 3. The printed medium placement unit 5 is located at the same position as the pre-printed medium placement unit 4 in the front-to-rear direction. The printed medium placement unit 5 is also located to the left of the table 13. In other words, when viewed from the front-to-rear direction, the table 13 is located between the pre-printed medium placement unit 4 and the printed medium placement unit 5. The printed medium placement unit 5 is also located on the anti-home position side, which is opposite the home position side of the carriage 10.

[0042] In the printed medium placement section 5, multiple sheets of media 2 can be placed. Specifically, in the printed medium placement section 5, multiple sheets of media 2 can be placed in a stacked manner. The multiple sheets of media 2 are placed in a stacked manner on the upper end of the printed medium placement section 5. In this embodiment, the upper end of the handle section 5a of the printed medium placement section 5, which is a wagon, becomes the upper end of the printed medium placement section 5. The height of the upper end of the handle section 5a is lower than the height of the upper surface of the table 13. In addition, the height of the upper end of the handle section 5a is slightly higher than the height of the upper end of the positioning pin 19.

[0043] (Configuration and operation of transport robot) The transport robot 6 is a vertical articulated robot. Specifically, the transport robot 6 is a six-axis vertical articulated robot. The transport robot 6 includes a hand 21 that holds the medium 2, an arm 22 to which the hand 21 is connected at its tip, a medium detection mechanism 23 for detecting the presence or absence of the medium 2 in the pre-printing medium placement unit 4, and a robot control unit 24 that controls the transport robot 6. The hand 21 of this embodiment suctions and holds the upper surface of the medium 2. The hand 21 includes a plurality of suction pads 25 that suctions the upper surface of the medium 2. The medium detection mechanism 23 of this embodiment is a pressure sensor. Therefore, in the following description, the medium detection mechanism 23 will be referred to as the "pressure sensor 23." The robot control unit 24 is electrically connected to the control device 7.

[0044] The hand 21 constitutes the tip of the transport robot 6. The base end of the transport robot 6 is fixed to the upper surface of a table 26. The table 26 is disposed in front of the table 13 of the printer 3. The table 26 is disposed between the pre-printing medium placement section 4 and the post-printing medium placement section 5 in the left-right direction, and is disposed at the same position as the pre-printing medium placement section 4 and the post-printing medium placement section 5 in the front-rear direction. The height of the upper surface of the table 26 is higher than the height of the medium placement surface 4a. The height of the upper surface of the table 26 is lower than the height of the upper surface of the table 13, the upper ends of the positioning pins 19, and the upper ends of the handle sections 5a.

[0045] As described above, the transport robot 6 transports the medium 2 from the pre-printing medium placement unit 4 to the printer 3, and also transports the medium 2 from the printer 3 to the post-printing medium placement unit 5. That is, the hand 21 holding the medium 2 moves from the pre-printing medium placement unit 4 to the printer 3, and also moves from the printer 3 to the post-printing medium placement unit 5. Specifically, the hand 21 holding the medium 2 moves from the pre-printing medium placement unit 4 to the table 13, and also moves from the table 13 to the post-printing medium placement unit 5. The hand 21 accesses the pre-printing medium placement unit 4, the post-printing medium placement unit 5, and the table 13 from above.

[0046] When the transport robot 6 transports the medium 2 from the pre-printing medium placement section 4 to the table 13, the hand 21 starts operation from a fixed position 21A (see FIGS. 2 and 3), which is a pre-specified position, moves to the pre-printing medium placement section 4 to grip the medium 2, and then moves to the table 13. Also, when the transport robot 6 transports the medium 2 from the table 13 to the post-printing medium placement section 5, the hand 21 starts operation from the fixed position 21A, moves to the table 13 to grip the medium 2, and then moves to the post-printing medium placement section 5. In other words, the fixed position 21A is the position of the hand 21 when the transport robot 6 starts the operation of transporting the medium 2.

[0047] Fixed position 21A is higher than the upper surface of table 13, the upper end of pre-printing medium placement section 4 (i.e., the upper end of positioning pin 19), and the upper end of post-printing medium placement section 5 (i.e., the upper end of handle section 5a) (see FIG. 3). Fixed position 21A is also higher than the upper end of emergency stop button 15. In other words, hand 21 placed at fixed position 21A is placed higher than the upper surface of table 13, the upper end of emergency stop button 15, the upper end of positioning pin 19, and the upper end of handle section 5a.

[0048] Also, the fixed position 21A is at a different position from the printer 3, the pre-printing medium placement unit 4, and the post-printing medium placement unit 5 when viewed from the top-bottom direction (see FIG. 2). That is, the fixed position 21A is at a position shifted from the printer 3, the pre-printing medium placement unit 4, and the post-printing medium placement unit 5 when viewed from the top-bottom direction, and the hand 21 placed at the fixed position 21A does not overlap with the printer 3, the pre-printing medium placement unit 4, and the post-printing medium placement unit 5 when viewed from the top-bottom direction. When viewed from above, the fixed position 21A in this embodiment is located in front of the table 13 that has moved forward and stopped, and is located to the left of the center of the table 13 in the left-right direction. That is, the hand 21 placed at the fixed position 21A is located in front of the table 13 that has moved forward and stopped, and is located to the left of the center of the table 13 in the left-right direction when viewed from above.

[0049] In this embodiment, the hand 21 moves to the fixed position 21A after transporting the medium 2 from the pre-printing medium placement unit 4 to the printer 3. The hand 21 also moves to the fixed position 21A after transporting the medium 2 from the printer 3 to the post-printing medium placement unit 5. After transporting the medium 2, the hand 21 moves to the fixed position 21A and stops at the fixed position 21A.

[0050] In addition, in this embodiment, the hand 21 passes through the fixed position 21A when moving from the pre-printing medium placement unit 4 to the printer 3. That is, the hand 21 holding the medium 2 passes through one fixed position 21A when moving from the pre-printing medium placement unit 4 to the table 13. At this time, the hand 21 may be temporarily stopped at the fixed position 21A, or may pass through the fixed position 21A without temporarily stopping at the fixed position 21A. Also, the hand 21 passes through the fixed position 21A when moving from the printer 3 to the post-printing medium placement unit 5. That is, the hand 21 holding the medium 2 passes through one fixed position 21A when moving from the table 13 to the post-printing medium placement unit 5. At this time, the hand 21 may be temporarily stopped at the fixed position 21A, or may pass through the fixed position 21A without temporarily stopping at the fixed position 21A.

[0051] The underside of the medium 2 held by the hand 21 disposed at the fixed position 21A is disposed above the upper surface of the table 13, the upper end of the emergency stop button 15, the upper end of the positioning pin 19, and the upper end of the handle portion 5a. The fixed position 21A in this embodiment is an entrance-side fixed position through which the hand 21 passes when moving from the pre-printing medium placement section 4 to the printer 3, and is also an exit-side fixed position through which the hand 21 passes when moving from the printer 3 to the post-printing medium placement section 5. That is, in this embodiment, the entrance-side fixed position and the exit-side fixed position are in the same position.

[0052] In this embodiment, when performing a return operation to return hand 21 disposed at an arbitrary position to fixed position 21A, hand 21 moves to the same height as fixed position 21A and then moves horizontally to return to fixed position 21A. The amount of movement of hand 21 in the vertical direction and the amount of movement of hand 21 in the horizontal direction when hand 21 performs the return operation are calculated by robot control unit 24.

[0053] When the transport robot 6 transports the medium 2 from the pre-printing medium placement section 4 to the printer 3, the hand 21 grips the second corner 2b side of the medium 2 in the pre-printing medium placement section 4. When the transport robot 6 transports the medium 2 from the pre-printing medium placement section 4 to the printer 3, the hand 21 rotates the hand 21 180° with the vertical direction as the axis of rotation. That is, when the transport robot 6 transports the medium 2 from the pre-printing medium placement section 4 to the printer 3, the hand 21 rotates the medium 2 180° with the vertical direction as the axis of rotation. In this embodiment, the right front end of the table 13 is the printing origin when printing on the medium 2 in the printer 3, and the first corner 2a of the medium 2 placed on the table 13 overlaps with the printing origin (see FIG. 2). When multiple sheets of media 2 are placed on the table 13, the first corner 2a of one sheet of media 2 among the multiple sheets of media 2 overlaps with the printing origin.

[0054] The pressure sensor 23 is attached to the hand 21. Specifically, the pressure sensor 23 is attached to each of the multiple suction pads 25, and the transport robot 6 is provided with multiple pressure sensors 23, the same number as the suction pads 25. When the medium 2 is suctioned by the suction pads 25, the output signal of the pressure sensor 23 varies. The pressure sensor 23 is electrically connected to the robot control unit 24, and the output signal of the pressure sensor 23 is input to the robot control unit 24. In this embodiment, when printing of the medium 2 is started in the printing system 1, the pressure sensor 23 detects whether or not the medium 2 is placed in the pre-printing medium placement unit 4, and detects the height of the uppermost medium 2 placed in the pre-printing medium placement unit 4.

[0055] Specifically, the hand 21, which is placed at a predetermined height above the pre-printing medium placement unit 4, is gradually lowered, and when the output signal of the pressure sensor 23 fluctuates by a predetermined amount before the hand 21 descends to the predetermined position, it is detected that a medium 2 is placed in the pre-printing medium placement unit 4. Furthermore, based on the height of the hand 21 when the output signal of the pressure sensor 23 fluctuates by the predetermined amount, the height of the medium 2 placed at the top in the pre-printing medium placement unit 4 (hereinafter, this medium 2 is referred to as the "topmost medium 2") is detected. The robot control unit 24 detects the height of the topmost medium 2 based on the output signal of the pressure sensor 23, calculates the number of media 2 to be stacked in the pre-printing medium placement unit 4 based on the detected height of the topmost medium 2, and stores the calculated number of media 2.

[0056] On the other hand, if the output signal of the pressure sensor 23 does not fluctuate by a predetermined amount even though the hand 21 has been lowered to a predetermined position in the pre-printing medium placement unit 4, it is detected that the medium 2 is not placed in the pre-printing medium placement unit 4. In this embodiment, when the pressure sensor 23 detects that the medium 2 is not placed in the pre-printing medium placement unit 4, the hand 21 stops on the spot. In other words, when the pressure sensor 23 detects that the medium 2 is not placed in the pre-printing medium placement unit 4, the hand 21 stops at the position where it was placed at the time when it was detected that the medium 2 was not placed in the pre-printing medium placement unit 4.

[0057] In this specification, when "the pressure sensor 23 detects that no medium 2 is placed in the pre-printing medium placement section 4", this includes not only cases where the pressure sensor 23 detects that no medium 2 is placed in the pre-printing medium placement section 4 because no medium 2 is placed in the pre-printing medium placement section 4 at all (i.e., because there is zero sheet of medium 2 placed in the pre-printing medium placement section 4), but also cases where the pressure sensor 23 detects that no medium 2 is placed in the pre-printing medium placement section 4 because the medium 2 is placed in the pre-printing medium placement section 4 but is placed in a position shifted from the position where it should be placed (more specifically, because the medium 2 is placed in a position that cannot be detected by the pressure sensor 23).

[0058] As described above, the robot control unit 24 calculates and stores the number of sheets of medium 2 stacked in the pre-printing medium placement unit 4 when printing of the medium 2 is started in the printing system 1. In addition, when printing of the medium 2 is performed in the printing system 1, the robot control unit 24 updates the stored number of sheets of medium 2 by reducing the number of sheets of medium 2 according to the number of operations of the hand 21 between the pre-printing medium placement unit 4 and the printer 3. In other words, the robot control unit 24 holds information on the current number of sheets of medium 2 placed in the pre-printing medium placement unit 4.

[0059] In this embodiment, the robot control unit 24 checks the current number of sheets of media 2 placed in the pre-printing medium placement unit 4 when the transport robot 6 starts the operation of transporting the media 2 from the pre-printing medium placement unit 4 to the printer 3. If the current number of sheets of media 2 checked by the robot control unit 24 is zero, the hand 21 stops at the fixed position 21A. More specifically, if the current number of sheets of media 2 checked by the robot control unit 24 is zero, the hand 21 remains stopped at the fixed position 21A.

[0060] When the medium 2 is placed on the pre-printing medium placement unit 4 after the hand 21 has stopped, the printer 3, for example, resets the count value of the number of sheets of the medium 2 printed by the printer 3. Also, when the medium 2 is placed on the pre-printing medium placement unit 4 after the hand 21 has stopped, the printer 3 may continue counting the number of sheets of the medium 2 printed by the printer 3 without resetting the count value of the number of sheets of the medium 2 printed by the printer 3.

[0061] Furthermore, in this embodiment, when the medium 2 is transported from the pre-printing medium placement unit 4 to the table 13, the pressure sensor 23 detects whether or not the hand 21 has held the medium 2 at the pre-printing medium placement unit 4. When the medium 2 is transported from the pre-printing medium placement unit 4 to the table 13, if the output signal of the pressure sensor 23 does not fluctuate by a predetermined amount even though the hand 21 has descended to a position at the pre-printing medium placement unit 4 where it can adsorb the medium 2, it is detected that the hand 21 has failed to hold the medium 2 at the pre-printing medium placement unit 4. The pressure sensor 23 in this embodiment is a medium holding detection mechanism for detecting that the hand 21 has held the medium 2 at the pre-printing medium placement unit 4.

[0062] In this embodiment, when pressure sensor 23 detects that hand 21 has failed to hold medium 2 in pre-printing medium placement unit 4, hand 21 stops on the spot. That is, when pressure sensor 23 detects that hand 21 has failed to hold medium 2, hand 21 stops at the position where it was located at the time when it was detected that it had failed to hold medium 2. On the other hand, when pre-printing medium placement unit 4 detects that hand 21 has held medium 2, hand 21 continues to move toward table 13.

[0063] In addition, when it is detected that the medium 2 is not placed in the pre-printing medium placement unit 4, or that the hand 21 has failed to hold the medium 2 in the pre-printing medium placement unit 4, or when the current number of sheets of medium 2 in the pre-printing medium placement unit 4 confirmed by the robot control unit 24 becomes zero, the robot control unit 24 transmits error information to the control device 7. The control device 7 that has received the error information may or may not transmit a command to stop the hand 21 to the robot control unit 24. If the control device 7 does not transmit a command to stop the hand 21, the robot control unit 24 transmits the error information to the control device 7 and stops the hand 21. If the control device 7 transmits a command to stop the hand 21, the robot control unit 24 stops the hand 21 after receiving the command to stop the hand 21 from the control device 7.

[0064] After it is detected that no medium 2 is placed in the pre-printing medium placement unit 4, or after the current number of sheets of medium 2 in the pre-printing medium placement unit 4 confirmed by the robot control unit 24 becomes 0, when the refilling of the pre-printing medium placement unit 4 with the medium 2 is completed, and after it is detected that the hand 21 in the pre-printing medium placement unit 4 has failed to hold the medium 2, when the removal of the medium 2 that was not held and maintenance of the hand 21 are completed (i.e., when a predetermined recovery operation is completed), for example, the operator performs a predetermined input operation in the control device 7 to automatically resume the operation of the printing system 1. Also, for example, if the transport robot 6 is equipped with a detection mechanism such as a camera for detecting that the recovery operation is completed, the operation of the printing system 1 may be automatically resumed based on the detection result of this detection mechanism when the recovery operation is completed.

[0065] Furthermore, when it is detected that no medium 2 is placed in the pre-printing medium placement unit 4, or that the hand 21 has failed to hold the medium 2 in the pre-printing medium placement unit 4, or when the current number of sheets of medium 2 in the pre-printing medium placement unit 4 confirmed by the robot control unit 24 becomes zero, the control unit 7 may execute a predetermined error process. For example, the control unit 7 may generate an alarm sound or send an error notification to the operator's smartphone. In this case, even if the operator is in a location away from the printing system 1, it becomes possible for the operator to quickly recognize that an error has occurred in the printing system 1.

[0066] (Printing system operation) FIG. 6 is a flowchart for explaining the operation of the printing system 1 shown in FIG.

[0067] When printing of the medium 2 is started in the printing system 1, the hand 21 is stopped at the fixed position 21A. When printing of the medium 2 is started in the printing system 1, the operator inputs the number of sheets of the medium 2 to be printed in the printing system 1 into the control device 7. After that, when the operator performs a predetermined operation in the control device 7 to start printing of the medium 2, the hand 21 moves to the pre-printing medium placement unit 4 based on a control command transmitted from the control device 7 to the robot control unit 24, and the transport robot 6 detects the presence or absence of the medium 2 in the pre-printing medium placement unit 4 and detects the height of the uppermost medium 2 (step S1). The robot control unit 24 also calculates the number of sheets of the medium 2 to be stacked in the pre-printing medium placement unit 4 based on the detected height of the uppermost medium 2, and stores the calculated number of sheets of the medium 2.

[0068] Thereafter, the hand 21 moves to the fixed position 21A and stops there (step S2). Thereafter, based on a control command sent from the control device 7 to the robot control unit 24, the transport robot 6 transports the medium 2 from the pre-printing medium placement unit 4 to the printer 3 (step S3). At this time, the hand 21 passes through the fixed position 21A. Also, at this time, the table 13 is positioned forward of the cover 17. Thereafter, the hand 21 moves to the fixed position 21A and stops there (step S4). Thereafter, based on a control command sent from the control device 7 to the printer control unit 16, the printer 3 performs printing on the medium 2 (step S5).

[0069] When printing of the medium 2 placed on the table 13 is completed, the transport robot 6 transports the medium 2 from the printer 3 to the post-printing medium placement unit 5 based on a control command sent from the control device 7 to the robot control unit 24 (step S6). At this time, the hand 21 passes through the fixed position 21A. Also, at this time, the table 13 moves to the front side of the cover 17 and stops. Thereafter, the hand 21 moves to the fixed position 21A and stops (step S7). Thereafter, the control device 7 judges whether printing of the designated number of sheets of the medium 2 is completed in the printing system 1 (step S8). If printing of the designated number of sheets of the medium 2 is not completed in step S8, the process returns to step S3. On the other hand, if printing of the designated number of sheets of the medium 2 is completed, printing of the medium 2 in the printing system 1 is completed.

[0070] (Main effects of this form) As described above, in this embodiment, when the pressure sensor 23 attached to the hand 21 detects that the medium 2 is not placed in the pre-printing medium placement section 4, the hand 21 stops at the position where it was placed at the time when it was detected that the medium 2 was not placed. Therefore, in this embodiment, the operator can visually check the position of the stopped hand 21 and the situation around the hand 21, and intuitively recognize that the transport robot 6 has stopped due to the absence of the medium 2 in the pre-printing medium placement section 4. Therefore, in this embodiment, it is easy for the operator to understand the reason why the transport robot 6 has stopped.

[0071] Furthermore, in this embodiment, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2 in the pre-printing medium placement unit 4, the hand 21 stops in the position where it was located at the time when the failure to hold the medium 2 was detected, so that the operator can visually check the position of the stopped hand 21 and the situation around the hand 21, and intuitively recognize that the transport robot 6 has stopped due to the hand 21 failing to hold the medium 2 in the pre-printing medium placement unit 4. Therefore, in this embodiment, it is easy for the operator to understand why the transport robot 6 has stopped.

[0072] In this embodiment, the robot control unit 24 holds information on the current number of sheets of medium 2 placed in the pre-printing medium placement unit 4, and confirms the current number of sheets of medium 2 placed in the pre-printing medium placement unit 4 when the transport robot 6 starts the transport operation of the medium 2 from the pre-printing medium placement unit 4 to the printer 3. In this embodiment, when the current number of sheets of medium 2 confirmed by the robot control unit 24 is 0, the hand 21 stops at the fixed position 21A. Furthermore, in this embodiment, the fixed position 21A is higher than the upper end of the pre-printing medium placement unit 4 and is a different position from the pre-printing medium placement unit 4 when viewed from the top and bottom, and the hand 21 stopped at the fixed position 21A is located at a position that is unlikely to cause any hindrance to the operator's work of placing the medium 2 in the pre-printing medium placement unit 4. Therefore, in this embodiment, when the current number of sheets of medium 2 confirmed by the robot control unit 24 is 0, the operator can easily perform the work of placing the medium 2 in the pre-printing medium placement unit 4 where the medium 2 has run out.

[0073] (Example of changing the printing system) Fig. 7 is a perspective view of a printing system 1 according to another embodiment of the present invention. Fig. 8 is a plan view of the printing system 1 shown in Fig. 7. In Figs. 7 and 8, the same reference numerals are used for the same configurations as those in the above-mentioned embodiment.

[0074] In the above-described embodiment, the printing system 1 may include two or more printers 3. For example, the printing system 1 may include three printers 3 as shown in Figs. 7 and 8. In the example shown in Figs. 7 and 8, the printing system 1 includes a printer 3 arranged behind the table 26, a printer 3 arranged to the right of the table 26, and a printer 3 arranged to the left of the table 26. For example, the size of the medium 2 printed by each of the three printers 3 is different. The configuration of the printing system 1 shown in Figs. 7 and 8 will be described below.

[0075] The pre-printing medium placement section 4 and the post-printing medium placement section 5 are disposed in front of the table 26. The pre-printing medium placement section 4 and the post-printing medium placement section 5 are adjacent to each other in the left-right direction. The pre-printing medium placement section 4 is disposed to the left of the post-printing medium placement section 5. In this modified example, the height of the upper end of the positioning pin 19 is higher than the height of the upper surface of the table 13.

[0076] The main scanning direction of the printer 3 arranged behind the table 26 coincides with the left-right direction, as in the embodiment described above. The main scanning direction of the printer 3 arranged to the right of the table 26 and the main scanning direction of the printer 3 arranged to the left of the table 26 are slightly inclined with respect to the front-rear direction. The main scanning direction of the printer 3 arranged to the right of the table 26 is inclined so as to move toward the right as it moves toward the rear in the front-rear direction. The main scanning direction of the printer 3 arranged to the left of the table 26 is inclined so as to move toward the left as it moves toward the rear in the front-rear direction. The inclination angle of the main scanning direction of the printer 3 arranged to the right of the table 26 and the main scanning direction of the printer 3 arranged to the left of the table 26 with respect to the front-rear direction is, for example, 5°.

[0077] In the printer 3 disposed behind the table 26, the emergency stop button 15 is disposed at the front end of the printer 3, as in the embodiment described above. In the printer 3 disposed to the right of the table 26, the emergency stop button 15 is disposed at the left end of the printer 3, and is disposed in front of the table 13 which has moved to the left and stopped. In the printer 3 disposed to the left of the table 26, the emergency stop button 15 is disposed at the right end of the printer 3, and is disposed behind the table 13 which has moved to the right and stopped.

[0078] 7 and 8, the main scanning direction of the printer 3 arranged on the right side of the table 26 and the main scanning direction of the printer 3 arranged on the left side of the table 26 are inclined with respect to the front-to-rear direction as described above, so even if the printers 3 are arranged behind the table 26 and on both sides in the left-to-right direction, the operator can easily access the table 13 and the transport robot 6 of the three printers 3. Therefore, even if the printing system 1 includes three printers 3, the operator's work on the table 13 and the transport robot 6 is unlikely to be hindered. Note that the main scanning direction of the printer 3 arranged on the right side of the table 26 and the main scanning direction of the printer 3 arranged on the left side of the table 26 may coincide with the front-to-rear direction.

[0079] As in the embodiment described above, when the transport robot 6 transports the medium 2 from the pre-printing medium placement section 4 to the table 13, and when the transport robot 6 transports the medium 2 from the table 13 to the post-printing medium placement section 5, the hand 21 starts operation from the fixed position 21A. The fixed position 21A is higher than the upper surface of the table 13, the upper end of the emergency stop button 15, the upper end of the pre-printing medium placement section 4, and the upper end of the post-printing medium placement section 5. In addition, the fixed position 21A is in a different position from the printer 3, the pre-printing medium placement section 4, and the post-printing medium placement section 5 when viewed from the top-down direction.

[0080] The fixed position 21A of the hand 21 for the printer 3 arranged behind the table 26, the fixed position 21A of the hand 21 for the printer 3 arranged to the right of the table 26, and the fixed position 21A of the hand 21 for the printer 3 arranged to the left of the table 26 are all in the same position. When viewed from above, for example, the fixed position 21A is located in front of the base end of the transport robot 6 and to the right of the center in the left-right direction of the table 13 of the printer 3 arranged behind the table 26 (see FIG. 8).

[0081] The fixed position 21A of the hand 21 for the printer 3 arranged behind the table 26, the fixed position 21A of the hand 21 for the printer 3 arranged to the right of the table 26, and the fixed position 21A of the hand 21 for the printer 3 arranged to the left of the table 26 may be different from each other. In other words, the fixed position 21A of the hand 21 may be different for each of the three printers 3, in which case three fixed positions 21A are specified.

[0082] As in the embodiment described above, the hand 21 passes through the fixed position 21A when moving from the pre-printing medium placement unit 4 to the printer 3 and when moving from the printer 3 to the post-printing medium placement unit 5. In this modified example, printing on the medium 2 is performed by three printers 3. In this modified example, between the above-mentioned steps S2 and S3, the printer 3 to which the medium 2 is to be loaded is identified based on a control command from the control device 7. In step S3, the transport robot 6 transports the medium 2 to the identified printer 3. Also, in this modified example, between the above-mentioned steps S5 and S6, the printer 3 to which the medium 2 is to be unloaded is identified based on a control command from the control device 7. In step S6, the transport robot 6 transports the medium 2 from the identified printer 3.

[0083] In this modified example, similarly to the embodiment described above, when the pressure sensor 23 attached to the hand 21 detects that the medium 2 is not placed in the pre-printing medium placement section 4, the hand 21 stops there. Also, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2 in the pre-printing medium placement section 4, the hand 21 stops there. Also, the robot control section 24 holds information on the current number of sheets of medium 2 placed in the pre-printing medium placement section 4, and checks the current number of sheets of medium 2 placed in the pre-printing medium placement section 4 when the transport robot 6 starts the transport operation of the medium 2 from the pre-printing medium placement section 4 to the printer 3, and if the current number of sheets of medium 2 confirmed by the robot control section 24 is 0, the hand 21 stops at the fixed position 21A. In this modified example as well, the same effect as in the embodiment described above can be obtained.

[0084] (Example of changing hand position) In the above-described embodiment, the fixed position 21A of the hand 21 may overlap the printer 3, the pre-printing medium placement unit 4, or the post-printing medium placement unit 5 when viewed from the top-down direction. Also, in the above-described embodiment, the fixed position 21A may be at a position lower than the upper end of the emergency stop button 15, or may be at the same position as the upper end of the emergency stop button 15 in the top-down direction. Furthermore, in the above-described embodiment, the fixed position 21A may be at a position lower than at least one of the upper surface of the table 13 and the upper end of the pre-printing medium placement unit 4. Also, the fixed position 21A may be at the same position as the upper surface of the table 13 or the upper end of the pre-printing medium placement unit 4 in the top-down direction.

[0085] (Example of changing the hand's carry-in and carry-out fixed positions) In the embodiment described above, the entrance fixed position through which the hand 21 moves from the pre-printing medium placement section 4 to the printer 3 and the discharge fixed position through which the hand 21 moves from the printer 3 to the printed medium placement section 5 are the fixed positions 21A, but at least one of the entrance fixed position and the discharge fixed position may be a position different from the fixed position 21A. Also, when the entrance fixed position and the discharge fixed position are a position different from the fixed position 21A, the entrance fixed position and the discharge fixed position may be the same position or may be different positions. Even in this case, the entrance fixed position and the discharge fixed position are, for example, higher than the top surface of the table 13, the upper end of the emergency stop button 15, the upper end of the pre-printing medium placement section 4, and the upper end of the printed medium placement section 5, and are positioned offset from the printer 3, the pre-printing medium placement section 4, and the printed medium placement section 5 when viewed from the top-bottom direction.

[0086] (Example of modification of media detection mechanism) In the above-described embodiment, the medium detection mechanism 23 for detecting the presence or absence of the medium 2 in the pre-print medium placement unit 4 may be a detection mechanism other than a pressure sensor. For example, the medium detection mechanism 23 may be an optical sensor having a light-emitting element and a light-receiving element. In this case, the medium detection mechanism 23 may be a reflective laser displacement sensor, for example. When the medium detection mechanism 23 is a laser displacement sensor, it becomes possible for the medium detection mechanism 23 to easily detect the height of the uppermost medium 2 placed in the pre-print medium placement unit 4.

[0087] Furthermore, the medium detection mechanism 23 may be, for example, a camera. When the medium detection mechanism 23 is a camera, it becomes possible for the medium detection mechanism 23 to detect the shape, etc. of the medium 2 placed in the pre-print medium placement unit 4. In this case, when the shape, etc. of the medium 2 detected by the medium detection mechanism 23 differs from the shape, etc. of the regular medium 2 to be printed by the printing system 1, it becomes possible to stop the operation of the transport robot 6 based on the detection result of the medium detection mechanism 23.

[0088] (Example of changing hand movements) In the embodiment described above, when the pressure sensor 23 detects that the medium 2 is not placed in the pre-printing medium placement section 4, the hand 21 may move to a predetermined position and then stop. For example, when it is detected that the medium 2 is not placed in the pre-printing medium placement section 4, the hand 21 may move to the fixed position 21A and then stop. As described above, the hand 21 stopped at the fixed position 21A is located at a position that is unlikely to interfere with the work of the operator to place the medium 2 in the pre-printing medium placement section 4, so in this case, it becomes easy for the operator to place the medium 2 in the pre-printing medium placement section 4 that has run out of the medium 2.

[0089] Also, for example, when the pressure sensor 23 detects that no medium 2 is placed in the pre-printing medium placement section 4, the hand 21 may move a predetermined amount upward in the pre-printing medium placement section 4 (rise a predetermined amount) and then stop. For example, when the pressure sensor 23 detects that no medium 2 is placed in the pre-printing medium placement section 4, the hand 21 may rise to the same position as the upper end of the pre-printing medium placement section 4 and then stop, or may rise to a height according to the number of sheets of medium 2 to be printed by the printing system 1 and then stop.

[0090] In this case, when it is detected that the medium 2 is not placed in the pre-printing medium placement section 4, it is possible to raise and stop the hand 21 to a position where the operator's work of placing the medium 2 in the pre-printing medium placement section 4 is not likely to be hindered. Therefore, it is possible for the operator to easily place the medium 2 in the pre-printing medium placement section 4 where the medium 2 has run out. Also, in this case, because the hand 21 is raised and stopped in the pre-printing medium placement section 4, when the transport robot 6 is operated after the medium 2 is placed in the pre-printing medium placement section 4, it is possible for the hand 21 to hold the medium 2 in the pre-printing medium placement section 4 in a short time.

[0091] In the embodiment described above, instead of the pressure sensor 23 attached to the hand 21, the pre-printing medium placement unit 4 may be provided with a medium detection mechanism for detecting the presence or absence of the medium 2. In this case, the medium detection mechanism is, for example, an optical sensor having a light emitting element and a light receiving element. In this case, when the transport robot 6 starts the operation of transporting the medium 2 from the pre-printing medium placement unit 4 to the printer 3, the medium detection mechanism detects whether or not the medium 2 is placed on the pre-printing medium placement unit 4.

[0092] Furthermore, in this case, when it is detected that no medium 2 is placed in the pre-printing medium placement section 4, the hand 21 stops at the fixed position 21A. More specifically, when it is detected that no medium 2 is placed in the pre-printing medium placement section 4, the hand 21 maintains its stopped state at the fixed position 21A. As described above, the hand 21 stopped at the fixed position 21A is located in a position that is unlikely to interfere with the operator's work of placing the medium 2 in the pre-printing medium placement section 4, so in this case, it becomes easy for the operator to place the medium 2 in the pre-printing medium placement section 4 from which the medium 2 has run out.

[0093] In the above embodiment, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2, the hand 21 may move to a predetermined position and then stop. For example, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2, the hand 21 may move to the fixed position 21A and then stop. As described above, the fixed position 21A is higher than the upper end of the pre-printing medium placement unit 4 and is offset from the pre-printing medium placement unit 4 when viewed from the top-down direction, and the hand 21 stopped at the fixed position 21A is stopped at a position that is unlikely to interfere with the operator's work, such as removing the medium 2 that was not held and maintaining the hand 21. Therefore, in this case, it is possible for the operator to easily perform recovery work when the hand 21 fails to hold the medium 2 in the pre-printing medium placement unit 4.

[0094] Also, for example, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2, the hand 21 may move a predetermined amount upward in the pre-printing medium placement unit 4 and then stop. For example, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2, the hand 21 may rise to the same position as the upper end of the pre-printing medium placement unit 4 and stop. In this case, when it is detected that the hand 21 has failed to hold the medium 2, it is possible to raise and stop the hand 21 to a position that is less likely to interfere with the operator's recovery work. Therefore, it is possible for the operator to easily perform the recovery work. Also, in this case, since the hand 21 has risen and stopped in the pre-printing medium placement unit 4, when the transport robot 6 is restarted after the recovery work is completed, the hand 21 can hold the medium 2 in a short time in the pre-printing medium placement unit 4.

[0095] In the above-described embodiment, the transport robot 6 or the pre-printing medium placement unit 4 may be provided with a medium holding detection mechanism for detecting that the hand 21 has held the medium 2 in the pre-printing medium placement unit 4, in addition to the pressure sensor 23 which is the medium holding mechanism. In this case, the medium holding detection mechanism is, for example, an optical sensor having a light emitting element and a light receiving element. In this case, when the medium holding detection mechanism detects that the hand 21 has failed to hold the medium 2, for example, the hand 21 stops on the spot. Also, when the medium holding detection mechanism detects that the hand 21 has failed to hold the medium 2, the hand 21 may move to a predetermined position and then stop. For example, the hand 21 may move to the fixed position 21A and then stop, or may move a predetermined amount upward in the pre-printing medium placement unit 4 and then stop.

[0096] (Other embodiments) The above-described embodiment is one example of a preferred embodiment of the present invention, but the present invention is not limited to this embodiment and various modifications are possible without departing from the spirit and scope of the present invention.

[0097] In the embodiment described above, the pre-print medium placing unit 4 is arranged to the right of the hand 21 arranged at the fixed position 21A, and the post-print medium placing unit 5 is arranged to the left of the hand 21 arranged at the fixed position 21A, but the pre-print medium placing unit 4 and the post-print medium placing unit 5 may be arranged to the right or left of the hand 21 arranged at the fixed position 21A. In other words, the pre-print medium placing unit 4 and the post-print medium placing unit 5 may be arranged to the right or left of the table 26.

[0098] In the embodiment described above, the hand 21 may hold the medium 2 by a method other than suction. For example, the hand 21 may have a gripping portion that contacts the upper surface of the medium 2 and a gripping portion that contacts the lower surface of the medium 2. In this case, the medium 2 is held by the hand 21 by being sandwiched between the two gripping portions from both sides in the top-bottom direction. The medium 2 may also be held by the hand 21 by being sandwiched between the two gripping portions from both sides in the front-back direction or the left-right direction. The medium 2 may also be held by the hand 21 by being placed on the hand 21.

[0099] In the embodiment described above, when the pre-printing medium placement section 4 and the table 13 are adjacent to each other, the hand 21 may push the medium 2 from the pre-printing medium placement section 4 toward the table 13, thereby transporting the medium 2 from the pre-printing medium placement section 4 to the table 13. In this case, the height of the medium placement surface 4a is slightly higher than the height of the upper surface of the table 13. Similarly, when the post-printing medium placement section 5 and the table 13 are adjacent to each other, the hand 21 may push the medium 2 from the table 13 toward the post-printing medium placement section 5, thereby transporting the medium 2 from the table 13 to the post-printing medium placement section 5. In other words, the hand 21 does not need to hold the medium 2.

[0100] In the above-described embodiment, multiple sheets of media 2 that are not overlapped with each other (i.e., not stacked) may be placed in the pre-print medium placement unit 4. Also, in the above-described embodiment, the pre-print medium placement unit 4 may be a conveyor such as a belt conveyor. In this case, for example, multiple sheets of media 2 that are not overlapped with each other are placed in the pre-print medium placement unit 4. Furthermore, in the above-described embodiment, the post-print medium placement unit 5 may include multiple positioning pins for positioning the medium 2 in the horizontal direction. Also, in the above-described embodiment, the upper surface of the table 13 may be inclined with respect to the horizontal direction. In this case, for example, the medium placement surface 4a of the pre-print medium placement unit 4 is parallel to the upper surface of the table 13.

[0101] In the embodiment described above, the height of the medium 2 placed on top in the pre-printing medium placement unit 4 does not have to be detected by the pressure sensor 23. In this case, for example, an operator inputs the number of sheets of medium 2 to be stacked in the pre-printing medium placement unit 4 to the robot control unit 24. The robot control unit 24 stores the input number of sheets of medium 2. Also, in the embodiment described above, the printer 3 may be provided with a Y-bar drive mechanism, instead of the table drive mechanism 14, that moves a Y-bar to which the guide rail 12 is fixed in the front-rear direction.

[0102] In the above-mentioned embodiment, the medium 2 may be a quadrilateral flat plate shape other than a rectangular shape and a square shape. For example, the medium 2 may be a flat plate shape such as a trapezoid, a rhombus, or a parallelogram. The medium 2 may also be a quadrilateral flat plate shape with a curved or flat chamfer (R chamfer or C chamfer) on at least one of the four corners. Furthermore, the medium 2 may be formed into a flat plate shape other than a rectangular shape and a square shape. For example, the medium 2 may be formed into a disk shape. The medium 2 may not be formed into a flat plate shape. For example, the medium 2 may be a ballpoint pen or the like formed into a cylindrical shape. In this case, the non-flat medium 2 may be stacked and arranged in the pre-printing medium arrangement unit 4. The medium 2 may also be a medium that is prone to sagging, such as paper or fabric.

[0103] In the above-mentioned embodiment, the transport robot 6 may be a vertical articulated robot other than a six-axis robot. Also, the transport robot 6 may be a robot other than a vertical articulated robot. For example, the transport robot 6 may be a horizontal articulated robot, an orthogonal robot, or a parallel link type robot. Furthermore, in the above-mentioned embodiment, the printing system 1 may include various devices such as a cutting device that cuts the medium 2 after printing or before printing, and a coating device that coats the medium 2 after printing. [Explanation of symbols]

[0104] 1 Printing System 2 medium 3 Printer (printing device) 4 Pre-print media placement section 6. Transport Robot 13 Tables 15 Emergency stop button 21 Hands 21A Fixed position 23 Pressure sensor (media detection mechanism, media retention detection mechanism) 24 Robot control unit Z vertical direction

Claims

1. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand that holds the medium, and a medium detection mechanism that detects the presence or absence of the medium in the pre-printing medium placement unit; The medium detection mechanism is attached to the hand, A printing system characterized in that, when the media detection mechanism detects that the media is not placed in the pre-printing media placement section, the hand stops at the position where it was placed at the time it was detected that the media was not placed.

2. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand that holds the medium, and a medium detection mechanism that detects the presence or absence of the medium in the pre-printing medium placement unit; The medium detection mechanism is attached to the hand, A printing system characterized in that, when the medium detection mechanism detects that the medium is not placed in the pre-printing medium placement section, the hand moves to a predetermined position and then stops.

3. The printing system described in claim 2, characterized in that when the media detection mechanism detects that the media is not placed in the pre-printing media placement section, the hand moves to a fixed position, which is the position of the hand when the transport robot begins the media transport operation, and then stops.

4. The printing system according to claim 2, characterized in that when the media detection mechanism detects that the media is not placed in the pre-printing media placement section, the hand moves a predetermined amount upward in the pre-printing media placement section and then stops.

5. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand that holds the medium and a robot control unit that controls the transport robot; a plurality of the media can be arranged in the pre-printing medium arrangement unit; the robot control unit holds information on the current number of sheets of media being placed on the pre-printing medium placement unit, and confirms the current number of sheets of media being placed on the pre-printing medium placement unit when the transport robot starts a transport operation of the media from the pre-printing medium placement unit to the printing device; A printing system characterized in that, when the current number of sheets of media confirmed by the robot control unit is 0, the hand stops at a fixed position, which is the position of the hand when the transport robot begins the medium transport operation.

6. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand for holding the medium, the pre-printing medium placement unit includes a medium detection mechanism for detecting the presence or absence of the medium; A printing system characterized in that when the transport robot starts the operation of transporting the medium from the pre-printing media placement section to the printing device, the media detection mechanism detects that the medium is not placed in the pre-printing media placement section, the hand stops at a fixed position which is the position of the hand when the transport robot starts the operation of transporting the medium.

7. A printing system as described in any one of claims 1 to 6, characterized in that the printing device resets a count value of the number of sheets of the medium printed by the printing device when the medium is placed in the pre-printing media placement section after the hand stops.

8. A printing system as described in any one of claims 1 to 6, characterized in that when the hand stops and the medium is placed in the pre-printing media placement section, the printing device continues counting the number of sheets of the medium printed by the printing device without resetting the count value of the number of sheets of the medium printed by the printing device.

9. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand for holding the medium, the transport robot or the pre-printing medium placement unit includes a medium holding detection mechanism for detecting that the hand has held the medium in the pre-printing medium placement unit, A printing system characterized in that when the media holding detection mechanism detects that the hand has failed to hold the media in the pre-printing media placement section, the hand stops at the position it was in at the time the failure to hold the media was detected.

10. a printing device that prints on a medium, a pre-printed medium placement unit that places the medium before printing, and a transport robot that transports the medium from the pre-printed medium placement unit to the printing device; the transport robot includes a hand for holding the medium, the transport robot or the pre-printing medium placement unit includes a medium holding detection mechanism for detecting that the hand has held the medium in the pre-printing medium placement unit, A printing system characterized in that, when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-printing media placement section, the hand moves to a predetermined position and then stops.

11. The printing system described in claim 10, characterized in that when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-printing media placement section, the hand moves to a fixed position, which is the position of the hand when the transport robot begins the media transport operation, and then stops.

12. A printing system as described in claim 10, characterized in that when the media holding detection mechanism detects that the hand has failed to hold the media in the pre-printing media placement section, the hand moves a predetermined amount upward in the pre-printing media placement section and then stops.

13. the printing device includes a table on which the medium is placed, 12. A printing system according to claim 3, 5, 6 or 11, wherein the fixed position is a position higher than an upper surface of the table and an upper end of the pre-printing medium placement unit.

14. the printing device includes an emergency stop button for causing an emergency stop of the printing device, 12. The printing system according to claim 3, 5, 6 or 11, wherein the fixed position is a position higher than an upper end of the emergency stop button.

15. 12. The printing system according to claim 3, 5, 6 or 11, wherein the fixed position is a position different from that of the printing device and the pre-printing medium placement unit when viewed from above and below.

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