Printing system

Abstract

The present invention proposes a specific operation of a conveyance robot when there is no medium on a pre-printing medium arrangement part in a printing system provided with a printing device for performing printing on a medium, a pre-printing medium arrangement part on which a medium before printing is arranged, and a conveyance robot for conveying the medium from the pre-printing medium arrangement part to a printing device.　This printing system 1 includes: a printing device 3 for performing printing on a medium 2; a pre-printing medium arrangement part 4 on which the medium 2 before printing is arranged; and a conveyance robot 6 for conveying the medium 2 from the pre-printing medium arrangement part 4 to the printing device 3. The conveyance robot 6 includes a hand 21 for holding the medium 2. A medium detection mechanism for detecting the presence or absence of the medium 2 on the pre-printing medium arrangement part 4 is attached to the hand 21, and when it is detected by the medium detection mechanism that the medium 2 is not arranged on the pre-printing medium arrangement part 4, the hand 21 stops on the spot.

Description

Printing System

[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.

[0002] Conventionally, printing systems that print on semiconductor substrates have been known (see, for example, Patent Document 1). The printing system described in Patent Document 1 includes an inkjet printer (applicator) that prints by ejecting droplets onto the semiconductor substrate, a transport robot (transporter) that transports the semiconductor substrate in the printing system, and a cooling unit that cools the semiconductor substrate before it is transported into the inkjet printer. The transport robot is a scalar robot that includes two arms and a hand (gripping unit) attached to the tip of the arm. The transport robot transports the semiconductor substrate from the cooling unit to the inkjet printer, for example.

[0003] JP 2012-183595 A

[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.Furthermore, 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 specific operations of the transport robot when there is no medium in the pre-printing medium placement unit in a printing system that includes a printing device that prints on 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 specific operations of the transport robot when there is no medium in the pre-printing medium placement unit in a printing system that includes a printing device that prints on 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 in the pre-printing medium placement unit fails to hold the medium.

[0006] In order to solve the first problem described above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-printing medium placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-printing medium placement section to the printing device, the transport robot comprising a hand that holds the medium and a medium detection mechanism for detecting the presence or absence of a medium in the pre-printing medium placement section, the medium detection mechanism being attached to the hand, and when the media detection mechanism 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 it was detected that no medium was placed.

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

[0008] In addition, in order to solve the first problem described above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-printing medium placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-printing medium 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 a medium in the pre-printing medium 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-printing medium 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 this 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 this invention, the operator can easily place 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 are 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 fixed position of 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, it becomes easier for the operator to place media in the pre-printing media placement section that has run out of media.

[0011] In the present invention, for example, when the media detection mechanism detects that no media are 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 are placed in the pre-printing media placement section, the hand may be raised to a position that is less likely to interfere with the operator's work of placing media in the pre-printing media placement section and then stopped, making it easier for the operator to place media in the pre-printing media placement section that has run out of media. Also, in this case, because the hand is raised and stopped in the pre-printing media placement section, when the transport robot is operated after placing media in the pre-printing media placement section, the hand can quickly hold the media in the pre-printing media placement section.

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

[0013] In the printing system of the present invention, the robot control unit maintains information on the current number of sheets of media being placed in the pre-printing media placement unit and checks the current number of sheets of media being placed in the pre-printing media placement unit when the transport robot begins transporting media from the pre-printing media placement unit to the printing device. If the current number of sheets of media confirmed by the robot control unit is zero, the hand stops at its fixed position, which is the position of the hand when the transport robot begins transporting media. Therefore, in this invention, by setting the fixed position of the hand to a position that is least likely to interfere with the operator's work of placing media in the pre-printing media placement unit when the current number of sheets of media confirmed by the robot control unit is zero, it is possible to stop the hand at a position that is least likely to interfere with the operator's work of placing media in the pre-printing media placement unit. Therefore, this invention makes it easier for the operator to place media in the pre-printing media placement unit when there is no media left.

[0014] Furthermore, in order to solve the first problem described above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-printing medium placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-printing medium placement section to the printing device, wherein the transport robot has a hand that holds the medium, and the pre-printing medium placement section has a media detection mechanism for detecting the presence or absence of the medium, and when the media detection mechanism detects that the medium is not placed in the pre-printing medium placement section when the transport robot starts the operation of transporting the medium from the pre-printing medium placement section to the printing device, the hand stops at a fixed position that is the position of the hand when the transport robot starts the operation of transporting the medium.

[0015] In the printing system of the present invention, when the transport robot begins transporting media from the pre-printing media placement unit to the printing device and the media detection mechanism detects that no media are placed in the pre-printing media placement unit, the hand stops at a fixed position, which is the hand's position when the transport robot begins transporting the media. Therefore, in this invention, by setting the hand position to a fixed position that is less likely to interfere with the operator's work of placing media in the pre-printing media placement unit, when the media detection mechanism detects that no media are placed in the pre-printing media placement unit, it is possible to stop the hand at a position that is less likely to interfere with the operator's work of placing media in the pre-printing media placement unit. Therefore, in this invention, the operator can easily place media in the pre-printing media placement unit when the media has run out.

[0016] In the present invention, for example, when the hand stops and media is placed in the pre-printing media placement section, the printing device resets the count value of the number of media printed by the printing device. Also, in the present invention, for example, when the hand stops and media is placed in the pre-printing media placement section, the printing device may continue counting the number of media printed by the printing device without resetting the count value of the number of media 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-printing medium placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-printing medium placement section to the printing device, wherein the transport robot has a hand that holds the medium, and the transport robot or the pre-printing medium placement section has a media holding detection mechanism for detecting that the hand is holding the medium in the pre-printing medium placement section, and 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 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 hold 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, by visually checking the position of the stopped hand and the situation around the hand, the operator can intuitively recognize that the transport robot has stopped because the hand 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 described above, the printing system of the present invention comprises a printing device that prints on a medium, a pre-printing medium placement section where the medium is placed before printing, and a transport robot that transports the medium from the pre-printing medium placement section to the printing device, wherein the transport robot has a hand that holds the medium, and the transport robot or the pre-printing medium placement section has a media holding detection mechanism for detecting that the hand has held the medium in the pre-printing medium placement section, and 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 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 in the pre-printing media placement unit has failed to hold the media, the hand moves to a predetermined position and then stops. Therefore, in the present invention, when it is detected that the hand in the pre-printing media placement unit has failed to hold the media, the hand can be moved and stopped to a position that is less likely to interfere with operator tasks such as removing the unheld media and maintaining the hand. Therefore, in the present invention, the operator can easily perform recovery tasks when the hand in the pre-printing media placement unit has failed to hold the media.

[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 medium placement section, the hand moves to a fixed position, which is the position of the hand when the transport robot begins its medium transport operation, and then stops. In this case, by setting the fixed position of the hand to a position that is less likely to interfere with operator work such as removing the unheld medium and maintaining the hand, it becomes easier for the operator to perform recovery work when the hand has failed to hold the medium in the pre-printing medium placement section.

[0022] In the present invention, for example, when the media hold detection mechanism detects that the hand in the pre-printing media placement section has failed to hold the medium, the hand may move upward a predetermined distance in the pre-printing media placement section and then stop. In this case, when the media hold detection mechanism detects that the hand in the pre-printing media placement section has failed to hold the medium, the hand may be raised and stopped to a position that is less likely to interfere with operator tasks such as removing the unheld medium and maintaining the hand, making it easier for the operator to perform recovery operations when the hand in the pre-printing media placement section has failed to hold the medium. Furthermore, in this case, because the hand in the pre-printing media placement section has been raised and stopped, when the transport robot is restarted after recovery operations are completed, the hand in the pre-printing media placement section can quickly hold the medium.

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

[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. Furthermore, the printing system of the present invention makes it easier for the operator to place media in the pre-printing media placement section when media has run out, and to perform recovery work when the hand in the pre-printing media placement section fails to hold the media.

[0027] 1 is a perspective view of a printing system according to an embodiment of the present invention. FIG. 2 is a plan view of the printing system shown in FIG. 1. FIG. 3 is a side view of the printing system shown in FIG. 1. FIG. 4 is a block diagram for explaining the configuration of the printing system shown in FIG. 1. FIG. 5 is a schematic diagram for explaining the configuration of the printing device shown in FIG. 1. FIG. 6 is a flowchart for explaining the operation of the printing system shown in FIG. 1. FIG. 7 is a perspective view of a printing system according to another embodiment of the present invention. FIG. 8 is a plan view of the printing system shown in FIG.

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

[0029] (Overall configuration of 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-printing medium placement section 4 where the pre-printing medium 2 is placed, a post-printing medium placement section 5 where the printed medium 2 is placed, a transport robot 6 that transports the medium 2 from the pre-printing medium placement section 4 to the printing device 3 and from the printing device 3 to the post-printing 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. In other words, 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. Furthermore, the medium 2 is formed, for example, from a resin such as acrylic resin. The control device 7 is, for example, a PC (personal computer).

[0031] The printing device 3 is a commercial inkjet printer. Therefore, in the following description, the printing device 3 will be referred to as the "printer 3." As shown in Figure 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 (the Y direction in Figure 5, etc.), and a guide rail 12 that guides the carriage 10 in the main scanning direction. The carriage 10, carriage drive mechanism 11, and 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 that moves 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 that controls the printer 3. In the following description, the main scanning direction is referred to as the left-right direction, and the sub-scanning direction is referred to as the front-to-rear direction. Furthermore, the Y1 direction in FIG. 1 , etc., which is one side of the left-to-right direction, is referred to as the "right" side, the Y2 direction in FIG. 1 , etc., which is the opposite side of the right side, is referred to as the "left" side, the X1 direction in FIG. 1 , etc., which is one side of the front-to-rear direction, is referred to as the "front" side, and the X2 direction in FIG. 1 , etc., which is the opposite side of the front, is referred to as the "rear" side.

[0033] The top surface of the table 13 is a plane perpendicular to the vertical direction. One or more sheets of media 2 are placed on the top surface of the table 13, depending on the size of the media 2, etc. The carriage 10 is located above the table 13. The head 9 ejects ink from above toward the media 2 placed on the top surface of the table 13. The carriage drive mechanism 11 includes, for example, a motor, a drive pulley that rotates with 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 being 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 to the right 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 comes to an emergency stop. The top 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 is placed on the pre-printing medium placement unit 4 before printing by the printer 3. The pre-printing medium placement unit 4 is located in front of the printer 3. The pre-printing medium placement unit 4 is also located to the right of the table 13. In other words, the pre-printing medium placement unit 4 is located on the home position side of the carriage 10.

[0037] The pre-printing medium placement unit 4 has 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 unit 4 is capable of placing multiple sheets of medium 2. Specifically, the pre-printing medium placement unit 4 is capable of placing multiple sheets of medium 2 in a stacked manner. In other words, the pre-printing medium placement unit 4 is capable of placing multiple sheets of medium 2 in a stacked manner. The multiple sheets of medium 2 are placed in a stack 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 preprint medium placement section 4 is equipped with a plurality of positioning pins 19 for positioning the medium 2 in the horizontal direction. The preprint medium placement section 4 in this embodiment is equipped 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 ends (upper end surfaces) of the positioning pins 19 form the upper end of the preprint medium placement section 4. The height of the upper ends 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 arranged at the left rear end of the pre-printing medium arrangement section 4. Two of the three positioning pins 19 are arranged at the same position in the front-to-rear direction and spaced apart in the left-to-right direction. The remaining positioning pin 19 is arranged 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-to-rear or left-to-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 contact the positioning pins 19. That is, as shown in FIG. 2 , if one corner on one diagonal of the quadrangular, flat plate-shaped medium 2 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 contacts the positioning pin 19.

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

[0042] The printed media placement section 5 is capable of placing multiple sheets of media 2. Specifically, the printed media placement section 5 is capable of placing multiple sheets of media 2 in a stacked manner. The multiple sheets of media 2 are placed in a stack at the upper end of the printed media placement section 5. In this embodiment, the upper end of the handle section 5a of the printed media placement section 5, which is a wagon, is the upper end of the printed media 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. The height of the upper end of the handle section 5a is also 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 that detects 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 in this embodiment suction-holds the top surface of the medium 2. The hand 21 includes multiple suction pads 25 that suction-hold the top surface of the medium 2. The medium detection mechanism 23 in 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 forms 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 located in front of the table 13 of the printer 3. The table 26 is located between the pre-printing medium placement section 4 and the post-printing medium placement section 5 in the left-right direction, and is located 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 also 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 portions 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 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 predetermined fixed position 21A (see FIGS. 2 and 3), 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] The fixed position 21A is higher than the upper surface of the table 13, the upper end of the pre-printing medium placement section 4 (i.e., the upper end of the positioning pin 19), and the upper end of the post-printing medium placement section 5 (i.e., the upper end of the handle section 5a) (see FIG. 3). The fixed position 21A is also higher than the upper end of the emergency stop button 15. In other words, the hand 21 placed at the fixed position 21A is placed higher than 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 section 5a.

[0048] Furthermore, the fixed position 21A is located 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 above (see FIG. 2). That is, the fixed position 21A is offset from the printer 3, the pre-printing medium placement unit 4, and the post-printing medium placement unit 5 when viewed from above, and the hand 21 located 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 above. In this embodiment, the fixed position 21A is located in front of the table 13, which 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. That is, the hand 21 located at the fixed position 21A is located in front of the table 13, which 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 temporarily stop 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 temporarily stop 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 positioned at fixed position 21A is positioned higher than 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. Fixed position 21A in this embodiment is both an entry-side fixed position through which the hand 21 passes when moving from the pre-printing medium placement section 4 to the printer 3, and 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. In other words, in this embodiment, the entry-side fixed position and the exit-side fixed position are in the same position.

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

[0053] When the transport robot 6 transports the medium 2 from the pre-printing medium placement unit 4 to the printer 3, the hand 21 grasps the second corner 2b of the medium 2 in the pre-printing medium placement unit 4. Furthermore, when transporting the medium 2 from the pre-printing medium placement unit 4 to the printer 3, the transport robot 6 rotates the hand 21 180° around the vertical direction as the axis of rotation. That is, when transporting the medium 2 from the pre-printing medium placement unit 4 to the printer 3, the transport robot 6 rotates the medium 2 180° around the vertical direction as the axis of rotation. In this embodiment, the right front end of the table 13 serves as 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 ). Note that, when multiple sheets of media 2 are placed on the table 13, the first corner 2a of one of the multiple sheets of media 2 overlaps with the printing origin.

[0054] The pressure sensor 23 is attached to the hand 21. Specifically, a pressure sensor 23 is attached to each of the plurality of suction pads 25, and the transport robot 6 is equipped with a plurality of pressure sensors 23, the same number as the suction pads 25. When the medium 2 is adsorbed to the suction pads 25, the output signal of the pressure sensor 23 fluctuates. 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 on the medium 2 begins in the printing system 1, the pressure sensor 23 detects whether 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 positioned 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 has been 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 on the topmost position in the pre-printing medium placement unit 4 (hereinafter, this medium 2 will be 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 descended 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 in place. 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 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 are zero sheets 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 medium 2 is placed in the pre-printing medium placement section 4 but is placed in a position that is 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 media 2 stacked in the pre-printing medium placement unit 4 when printing on the media 2 begins in the printing system 1. Furthermore, when printing on the media 2 in the printing system 1, the robot control unit 24 updates the stored number of sheets of media 2 by reducing the number of times the hand 21 operates 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 media 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 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 in the pre-printing medium placement unit 4 after the hand 21 has stopped, the printer 3 resets, for example, the count value of the number of sheets of the medium 2 printed by the printer 3. Also, when the medium 2 is placed in 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 the hand 21 has held the medium 2 in 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 in 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 in the pre-printing medium placement unit 4. The pressure sensor 23 in this embodiment is a medium holding detection mechanism that detects that the hand 21 has held the medium 2 in the pre-printing medium placement unit 4.

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

[0063] Note that if 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 if 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 sends error information to the control device 7. The control device 7 that has received the error information may or may not send a command to stop the hand 21 to the robot control unit 24. If the control device 7 does not send a command to stop the hand 21, the robot control unit 24 sends the error information to the control device 7 and stops the hand 21. If the control device 7 sends 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 media 2 are placed in the pre-printing medium placement unit 4, or after the current number of media 2 in the pre-printing medium placement unit 4 confirmed by the robot control unit 24 has reached zero, when the pre-printing medium placement unit 4 has been refilled with media 2, or after it is detected that the hand 21 in the pre-printing medium placement unit 4 has failed to hold the media 2, when the removal of the media 2 that was not held or maintenance of the hand 21 is completed (i.e., when a predetermined recovery operation is completed), for example, an operator performs a predetermined input operation on the control device 7 to automatically resume operation of the printing system 1. Furthermore, for example, if the transport robot 6 is equipped with a detection mechanism such as a camera for detecting the completion of the recovery operation, the operation of the printing system 1 may be automatically resumed when the recovery operation is completed based on the detection result of this detection mechanism.

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

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

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

[0068] The hand 21 then moves to and stops at the fixed position 21A (step S2). Then, 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 in front of the cover 17. Then, the hand 21 moves to and stops at the fixed position 21A (step S4). Then, based on a control command sent from the control device 7 to the printer control unit 16, the printer 3 prints on the medium 2 (step S5).

[0069] When printing on 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-printed 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 forward of the cover 17 and stops. The hand 21 then moves to the fixed position 21A and stops (step S7). The control device 7 then determines whether printing on the specified number of sheets of medium 2 has been completed in the printing system 1 (step S8). If printing on the specified number of sheets of medium 2 has not been completed in step S8, the process returns to step S3. On the other hand, if printing on the specified number of sheets of medium 2 has been completed, printing on the medium 2 in the printing system 1 is completed.

[0070] (Major Effects of the Present Embodiment) As described above, in the present 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 unit 4, the hand 21 stops in the position where it was placed at the time it was detected that the medium 2 was not placed. Therefore, in the present embodiment, by the operator visually checking the position of the stopped hand 21 and the situation around the hand 21, the operator can intuitively recognize that the transport robot 6 has stopped because the medium 2 is not placed in the pre-printing medium placement unit 4. Therefore, in the present embodiment, the operator can easily understand the cause of the transport robot 6 being 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 the failure to hold the medium 2 was detected, and therefore 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 because the hand 21 failed 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 the cause of the transport robot 6 being stopped.

[0072] In this embodiment, the robot control unit 24 retains information on the current number of sheets of media 2 being placed in the pre-printing medium placement unit 4 and confirms the current number of sheets of media 2 being placed in the pre-printing medium placement unit 4 when the transport robot 6 begins transporting the media 2 from the pre-printing medium placement unit 4 to the printer 3. In this embodiment, if the current number of sheets of media 2 confirmed by the robot control unit 24 is zero, the hand 21 stops at the home position 21A. Furthermore, in this embodiment, the home position 21A is higher than the top of the pre-printing medium placement unit 4 and is at a different position from the pre-printing medium placement unit 4 when viewed from above. The hand 21 stopped at the home position 21A is positioned to minimize interference with the operator's work of placing media 2 in the pre-printing medium placement unit 4. Therefore, in this embodiment, when the current number of sheets of media 2 confirmed by the robot control unit 24 is zero, the operator can easily place media 2 in the pre-printing medium placement unit 4 that has run out of media 2.

[0073] (Modification of 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 to designate the same components as those in the above-described embodiment.

[0074] In the embodiment described above, 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 Figures 7 and 8. In the example shown in Figures 7 and 8, the printing system 1 includes a printer 3 located behind the table 26, a printer 3 located to the right of the table 26, and a printer 3 located to the left of the table 26. For example, the sizes of the media 2 printed by each of the three printers 3 are different. The configuration of the printing system 1 shown in Figures 7 and 8 will be described below.

[0075] The pre-printing medium placement section 4 and the post-printing medium placement section 5 are located 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 located 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-to-rear direction. The main scanning direction of the printer 3 arranged to the right of the table 26 is inclined so as to move to the right as it moves rearward in the front-to-rear direction. The main scanning direction of the printer 3 arranged to the left of the table 26 is inclined so as to move leftward in the front-to-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-to-rear direction is, for example, 5°.

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

[0078] 7 and 8 , the main scanning direction of the printer 3 located to the right of the table 26 and the main scanning direction of the printer 3 located to the left of the table 26 are inclined with respect to the front-to-rear direction as described above, so even if printers 3 are located behind the table 26 and on both the left and right sides, the operator can easily access the tables 13 and the transport robot 6 of the three printers 3. Therefore, even if the printing system 1 is equipped with three printers 3, the operator's work on the tables 13 and the transport robot 6 is less likely to be hindered. Note that the main scanning direction of the printer 3 located to the right of the table 26 and the main scanning direction of the printer 3 located to the left 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 unit 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 unit 5, the hand 21 starts operation from the fixed position 21A. The fixed position 21A is higher than the top surface of the table 13, the top end of the emergency stop button 15, the top end of the pre-printing medium placement unit 4, and the top end of the post-printing medium placement unit 5. Furthermore, the fixed position 21A is in 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 and bottom.

[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 located behind the table 26, the fixed position 21A of the hand 21 for the printer 3 located to the right of the table 26, and the fixed position 21A of the hand 21 for the printer 3 located to the left of the table 26 may be in different positions. In other words, the fixed position 21A of the hand 21 may be in a different position 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 loaded 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, similar to the embodiment described above, when the pressure sensor 23 attached to the hand 21 detects that no media 2 are placed in the pre-printing medium placement unit 4, the hand 21 stops in place. Furthermore, when the pressure sensor 23 detects that the hand 21 has failed to hold the media 2 in the pre-printing medium placement unit 4, the hand 21 stops in place. Furthermore, the robot control unit 24 retains information on the current number of sheets of media 2 being placed in the pre-printing medium placement unit 4, and checks the current number of sheets of media 2 being placed in the pre-printing medium placement unit 4 when the transport robot 6 begins 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 confirmed by the robot control unit 24 is zero, the hand 21 stops at the home position 21A. This modified example also provides the same effects as the embodiment described above.

[0084] (Example of modification of the fixed position of the hand) In the embodiment described above, 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 embodiment described above, the fixed position 21A may be 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 embodiment described above, the fixed position 21A may be 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 Modification of Hand Intake-Side Desired Position and Outtake-Side Desired Position) In the embodiment described above, the take-in-side designated position through which the hand 21 passes when moving from the pre-printing media placement section 4 to the printer 3 and the outtake-side designated position through which the hand 21 passes when moving from the printer 3 to the printed media placement section 5 are designated as designated positions 21A. However, at least one of the take-in-side designated position and the outtake-side designated position may be located at a position different from designated position 21A. Furthermore, when the take-in-side designated position and the outtake-side designated position are located at a position different from designated position 21A, the take-in-side designated position and the outtake-side designated position may be located at the same position or at different positions. Even in this case, the take-in-side designated position and the outtake-side designated position are located at a position higher than, for example, the top surface of the table 13, the top end of the emergency stop button 15, the top end of the pre-printing media placement section 4, and the top end of the printed media placement section 5, and are positioned offset from the printer 3, the pre-printing media placement section 4, and the printed media placement section 5 when viewed from above.

[0086] (Modification of the Medium Detection Mechanism) In the embodiment described above, 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. If the medium detection mechanism 23 is a laser displacement sensor, the medium detection mechanism 23 can 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. If the medium detection mechanism 23 is a camera, it will be possible for the medium detection mechanism 23 to detect the shape, etc. of the medium 2 placed in the pre-printing medium placement unit 4. In this case, if 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 on by the printing system 1, it will be possible to stop the operation of the transport robot 6 based on the detection result of the medium detection mechanism 23.

[0088] (Modification of Hand Operation) In the embodiment described above, 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 to a predetermined position and then stop. For example, when it is detected that no medium 2 is 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 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. In this case, the operator can easily place the medium 2 in the pre-printing medium placement section 4 that has run out of the medium 2.

[0089] Furthermore, 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 upward (rise a predetermined amount) in the pre-printing medium placement section 4 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 corresponding 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 no medium 2 has been placed in the pre-printing medium placement unit 4, it is possible to raise and stop the hand 21 to a position that is less likely to interfere with the operator's work of placing the medium 2 in the pre-printing medium placement unit 4. Therefore, it is possible for the operator to easily place the medium 2 in the pre-printing medium placement unit 4 that has run out of the medium 2. Also, in this case, because the hand 21 has been raised and stopped in the pre-printing medium placement unit 4, when the transport robot 6 is operated after the medium 2 has been placed in the pre-printing medium placement unit 4, the hand 21 can hold the medium 2 in the pre-printing medium placement unit 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 equipped 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 begins transporting the medium 2 from the pre-printing medium placement unit 4 to the printer 3, the medium detection mechanism detects whether the medium 2 is placed in 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 remains stopped 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, the operator can easily place the medium 2 in the pre-printing medium placement section 4 that has run out of the medium 2.

[0093] In the above-described 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 home position 21A and then stop. As described above, the home position 21A is higher than the top 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 and bottom. The hand 21 stopped at the home position 21A is stopped at a position that is less likely to interfere with operator tasks such as removing the unheld medium 2 and maintaining the hand 21. Therefore, in this case, the operator can easily perform recovery operations when the hand 21 fails to hold the medium 2 in the pre-printing medium placement unit 4.

[0094] Furthermore, for example, when the pressure sensor 23 detects that the hand 21 has failed to hold the medium 2, the hand 21 may move upward a predetermined distance 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, the hand 21 can be raised and stopped to a position that is less likely to interfere with the operator's recovery work. This makes it easier for the operator to perform the recovery work. Furthermore, in this case, because 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 quickly hold the medium 2 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 include, in addition to the pressure sensor 23, which is the medium holding mechanism, a medium holding detection mechanism for detecting that the hand 21 is holding the medium 2 in the pre-printing medium placement unit 4. 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, the hand 21 may stop, for example. Alternatively, 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 and various modifications can be made within the scope that does not change the gist of the present invention.

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

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

[0099] In the above-described embodiment, when the pre-printing medium placement unit 4 and the table 13 are adjacent to each other, the hand 21 may push the medium 2 from the pre-printing medium placement unit 4 toward the table 13, thereby transporting the medium 2 from the pre-printing medium placement unit 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 unit 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 unit 5, thereby transporting the medium 2 from the table 13 to the post-printing medium placement unit 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 may be placed in the pre-printing media placement unit 4 without overlapping each other (i.e., not stacked). Also, in the above-described embodiment, the pre-printing media placement unit 4 may be a conveyor such as a belt conveyor. In this case, for example, multiple sheets of media 2 are placed in the pre-printing media placement unit 4 without overlapping each other. Furthermore, in the above-described embodiment, the post-printing media placement unit 5 may be provided with multiple positioning pins for positioning the media 2 in the horizontal direction. Also, in the above-described embodiment, the upper surface of the table 13 may be inclined relative to the horizontal direction. In this case, for example, the medium placement surface 4 a of the pre-printing media placement unit 4 is parallel to the upper surface of the table 13.

[0101] In the above-described embodiment, the pressure sensor 23 does not have to detect the height of the topmost medium 2 placed in the pre-printing medium placement unit 4. 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 into the robot control unit 24. The robot control unit 24 stores the input number of sheets of medium 2. Also, in the above-described embodiment, 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 forward and backward directions.

[0102] In the above-described embodiment, the medium 2 may be a flat quadrilateral shape other than a rectangular or square shape. For example, the medium 2 may be a flat trapezoid, rhombus, parallelogram, or other shape. The medium 2 may also be a flat quadrilateral shape with at least one of its four corners chamfered (R-chamfered or C-chamfered) in a curved or flat shape. Furthermore, the medium 2 may be formed into a flat plate shape other than a rectangular or square shape. For example, the medium 2 may be formed into a disk shape. The medium 2 does not have to be formed into a flat plate shape. For example, the medium 2 may be a cylindrical ballpoint pen or the like. In this case, non-flat media 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-described embodiment, the transport robot 6 may be a vertical articulated robot other than a six-axis robot. Furthermore, 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, a Cartesian robot, or a parallel-link robot. Furthermore, in the above-described embodiment, the printing system 1 may be equipped with 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.

[0104] REFERENCE SIGNS LIST 1 Printing system 2 Medium 3 Printer (printing device) 4 Pre-printing medium placement unit 6 Transport robot 13 Table 15 Emergency stop button 21 Hand 21A Fixed position 23 Pressure sensor (medium detection mechanism, medium holding detection mechanism) 24 Robot control unit Z Up-down direction

Claims

1. A printing system comprising: a printing device that prints on media; a pre-print media placement section where the media is placed before printing; and a transport robot that transports the media from the pre-print media placement section to the printing device, wherein the transport robot has a hand that holds the media and a media detection mechanism for detecting the presence or absence of the media in the pre-print media placement section, the media detection mechanism is attached to the hand, and when the media detection mechanism detects that the media is not placed in the pre-print media placement section, the hand stops at the position where it was located at the time it was detected that the media was not placed.

2. A printing system comprising: a printing device that prints on media; a pre-print media placement section where the media is placed before printing; and a transport robot that transports the media from the pre-print media placement section to the printing device, wherein the transport robot has a hand that holds the media and a media detection mechanism for detecting the presence or absence of the media in the pre-print media placement section, the media detection mechanism is attached to the hand, and when the media detection mechanism detects that the media is not placed in the pre-print media 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. A printing system as 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 a predetermined amount upward in the pre-printing media placement section and then stops.

5. A printing system comprising: a printing device that prints on media; a pre-print media placement section where the media is placed before printing; and a transport robot that transports the media from the pre-print media placement section to the printing device, wherein the transport robot has a hand that holds the media and a robot control section that controls the transport robot, wherein the pre-print media placement section is capable of placing a plurality of the media, wherein the robot control section retains information on the current number of the media being placed in the pre-print media placement section and checks the current number of the 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 wherein if the current number of the media confirmed by the robot control section 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.

6. A printing system comprising: a printing device that prints on media; a pre-print media placement section where the media is placed before printing; and a transport robot that transports the media from the pre-print media placement section to the printing device, wherein the transport robot has a hand that holds the media, and the pre-print media placement section has a media detection mechanism for detecting the presence or absence of the media, and when the media detection mechanism detects that the media is not 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, 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.

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

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 system comprising: a printing device that prints on media; a pre-print media placement section where the media 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 transport robot or the pre-print media placement section has a media holding detection mechanism for detecting that the hand is holding the medium in the pre-print media placement section, and when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-print media placement section, the hand stops at the position it was in at the time it was detected that it had failed to hold the medium.

10. A printing system comprising: 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 transport robot or the pre-print media placement section has a media holding detection mechanism for detecting that the hand is holding the medium in the pre-print media placement section, and when the media holding detection mechanism detects that the hand has failed to hold the medium in the pre-print media placement section, the hand moves to a predetermined position and then stops.

11. 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 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. A printing system as described in claim 3, 5, 6 or 11, characterized in that the printing device is provided with a table on which the medium is placed, and the fixed position is a position higher than the upper surface of the table and the upper end of the pre-printing medium placement section.

14. A printing system as described in claim 3, 5, 6 or 11, characterized in that 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.

15. A printing system as described in claim 3, 5, 6 or 11, characterized in that, when viewed from above and below, the fixed position is a position different from that of the printing device and the pre-printing medium placement unit.

Images