Inkjet printer

Abstract

To detect an end of a recording medium while suppressing drying of a nozzle of an ink head.SOLUTION: A printer 10 includes: an ink head 24 which has a nozzle surface 25 provided with a nozzle for discharging ink to a recording medium 5 mounted in a platen 16; a first carriage 28 which is mounted with the ink head 24 thereon and is movable in a main scanning direction Y; a first sensor 31 which detects an end in a main scanning direction Y of the recording medium 5; a second carriage 38 which is detachably provided in the first carriage 28, is mounted with the first sensor 31 thereon, and is movable in the main scanning direction Y; a carriage moving mechanism 40 which moves the second carriage 38; and a cap 71 which forms a sealed space 26 between the cap and the nozzle surface 25 when mounted in the ink head 24. The cap 71 is mounted in the ink head 24 and forms the sealed space 26 between the cap and the nozzle surface 25 when the second carriage 38 independently moves.SELECTED DRAWING: Figure 3B

Description

Technical Field

[0001] The present invention relates to an inkjet printer.

Background Art

[0002] Conventionally, an inkjet printer that prints on a recording medium by an inkjet method is known. This type of inkjet printer includes, for example, a platen on which a recording medium is placed, an ink head having nozzles that eject ink onto the recording medium placed on the platen, and a nozzle surface on which the nozzles are formed, and a carriage on which the ink head is mounted. In an inkjet printer, it is usually necessary to detect the position of the recording medium and the like before starting printing. For example, Patent Document 1 discloses an inkjet printer in which an optical sensor for detecting an end of a recording medium is mounted on a carriage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Here, in the technology disclosed in Patent Document 1, when detecting the end of a recording medium, it is necessary to move a carriage equipped with an optical sensor in the main scanning direction. Here, since an ink head is mounted on the carriage in addition to the optical sensor, when detecting the end of the recording medium, the ink head also moves in the main scanning direction. When the carriage moves in the main scanning direction across the printing area, the nozzle surface of the ink head is exposed to the outside. Therefore, if ink is not ejected from the nozzles, there is a risk that the nozzles and the nozzle surface will dry out. When the nozzles and the like dry out, there is a risk that the nozzles will become clogged or the ink will adhere to the nozzle surface. For this reason, after detecting the end of the recording medium with the optical sensor, a cleaning operation for ejecting ink from the nozzles is required. Since the cleaning operation takes a relatively long time and also consumes a relatively large amount of ink used, it is desired to reduce the cleaning operation when detecting the end of the recording medium.

[0005] The present invention has been made in view of such a point, and an object thereof is to provide an inkjet printer capable of detecting the end of a recording medium while suppressing drying of the nozzles of an ink head.

Means for Solving the Problem

[0006] The inkjet printer according to the present invention includes a mounting table on which a recording medium is placed, a nozzle that discharges ink onto the recording medium placed on the mounting table, and a nozzle surface on which the nozzle is formed. The inkjet printer also includes an ink head having the above components, a first carriage on which the ink head is mounted and which is movable in the main scanning direction, a first sensor that detects an end of the recording medium placed on the mounting table in the main scanning direction, a second carriage that is detachably provided on the first carriage and on which the first sensor is mounted and which is movable in the main scanning direction, a carriage moving mechanism that moves the second carriage in the main scanning direction, a cap that is detachably formed on the ink head and that covers the nozzle surface and forms a sealed space between the cap and the nozzle surface when attached to the ink head, and a control device connected to the first sensor. The cap is configured to be attached to the ink head and form the sealed space between the cap and the nozzle surface when the second carriage moves independently.

[0007] According to the inkjet printer of the present invention, the second carriage on which the first sensor for detecting the end of the recording medium in the main scanning direction is mounted is detachably provided on the first carriage on which the ink head is mounted. Therefore, when detecting the end of the recording medium in the main scanning direction by the first sensor, the second carriage can move independently in the main scanning direction from the first carriage. Here, when the second carriage moves independently, a cap is attached to the ink head and a sealed space is formed between the cap and the nozzle surface. For this reason, the nozzle and the nozzle surface are not exposed to the outside, and drying of the nozzle and the nozzle surface is suppressed. In this way, when detecting the end of the recording medium in the main scanning direction, since a cap is attached to the ink head, a cleaning operation for discharging ink from the nozzle becomes unnecessary.

Effects of the Invention

[0008] According to the present invention, it is possible to provide an inkjet printer that can detect the end of a recording medium while suppressing drying of the nozzles of the ink head.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0010] Hereinafter, an inkjet printer (hereinafter simply referred to as "printer") according to an embodiment of the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are not intended to limit the present invention in particular. Also, members and parts having the same function are denoted by the same reference numerals, and redundant descriptions are omitted or simplified as appropriate.

[0011] FIG. 1 is a front view showing the printer 10 according to the present embodiment. The printer 10 performs printing on the recording medium 5. The recording medium 5 is formed in a long shape, for example, and is used by being wound in a roll shape. Note that the recording medium 5 may be in the form of a sheet obtained by cutting a roll-shaped one to a predetermined length. The recording medium 5 is, for example, recording paper. However, the recording medium 5 is not limited to recording paper. The recording medium 5 includes, in addition to papers such as plain paper and inkjet printing paper, those formed from resin materials such as polyvinyl chloride (PVC) and polyester, metal plates formed from aluminum, iron, etc., glass plates, wood plates, and those formed from cardboard and the like. When the recording medium 5 is formed from paper or a resin material, the color of the recording medium 5 is typically white.

[0012] In the following description, left, right, up, and down shall respectively mean left, right, up, and down as viewed from an operator standing in front of the printer 10. Also, when the operator is facing the front of the printer 10, the direction from the rear of the printer 10 toward the operator is the front, and the direction from the operator toward the rear of the printer 10 is the rear. The reference signs F, Rr, L, R, U, and D in the drawings represent front, rear, left, right, up, and down, respectively. The first carriage 28 and the second carriage 38 described later are provided so as to be movable leftward and rightward. When the rear side of the printer 10 is referred to as the upstream side and the front side of the printer 10 is referred to as the downstream side, the recording medium 5 is conveyed from the upstream side toward the downstream side. In the present embodiment, the moving direction of the first carriage 28 and the second carriage 38 is referred to as the main scanning direction Y, and the conveying direction of the recording medium 5 is referred to as the sub-scanning direction X. Here, the main scanning direction Y corresponds to the left-right direction, and the sub-scanning direction X corresponds to the front-rear direction. The main scanning direction Y and the sub-scanning direction X are orthogonal to each other. However, the main scanning direction Y and the sub-scanning direction X are not particularly limited, and can be appropriately set according to the form of the printer 10 and the like.

[0013] As shown in FIG. 1, the printer 10 includes a printer main body 10a, legs 11, an operation panel 12, a platen 16 on which a recording medium 5 is placed, an ink head unit 20, a sensor unit 30, a carriage movement mechanism 40, a medium movement mechanism 55, a first control device 80, and a second control device 90 (see FIG. 3A). The printer main body 10a has a casing extending in the main scanning direction Y. The legs 11 support the printer main body 10a and are provided on the lower surface of the printer main body 10a. The operation panel 12 is provided, for example, on the front surface on the right side of the printer main body 10a. However, the position of the operation panel 12 is not particularly limited. The operation panel 12 is, for example, for an operator to perform operations related to printing. Although illustration is omitted, the operation panel 12 is provided with, for example, a display unit for displaying information related to printing such as resolution and ink density, and the status of the printer 10 during printing, and an input unit for inputting information related to printing.

[0014] The platen 16 supports the recording medium 5 when printing on the recording medium 5. The recording medium 5 is placed on the platen 16. The platen 16 has a placement surface 16A (see FIG. 2) on which the recording medium 5 is placed. In the present embodiment, the placement surface 16A is black, but the color of the placement surface 16A is not limited to black. The recording medium 5 is placed on the placement surface 16A of the platen 16 before printing on the recording medium 5. The platen 16 is an example of a mounting table. Printing on the recording medium 5 is performed on the platen 16. As shown in FIG. 1, the platen 16 extends in the main scanning direction Y. The platen 16 is supported by the printer main body 10a.

[0015] As shown in FIG. 2, a plurality of suction holes 16H penetrating in the vertical direction are formed through the platen 16. The suction holes 16H include a downstream suction hole 16HF located forward (i.e., on the downstream side in the sub-scanning direction X) of an ink head 24 described later, and an upstream suction hole 16HR located rearward (i.e., on the upstream side in the sub-scanning direction X) of the ink head 24. As shown in FIG. 4, the downstream suction holes 16HF and the upstream suction holes 16HR are arranged side by side in the main scanning direction Y, and are arranged in two rows in the sub-scanning direction X, respectively. As shown by the arrow FL in FIG. 2, air is sucked from the suction holes 16H into the inside of the platen 16 by a fan (not shown). Thereby, the recording medium 5 placed on the platen 16 is attracted to the platen 16, and the lifting of the recording medium 5 is suppressed. Further, as shown in FIG. 4, a groove 16D extending in the main scanning direction Y is formed in the platen 16. The groove 16D is formed over the entire length of the platen 16 in the main scanning direction Y. The groove 16D is formed between the upstream suction holes 16HR arranged in two rows in the sub-scanning direction X.

[0016] As shown in FIG. 1, the printer 10 includes a central wall 14 extending in the main scanning direction Y and the vertical direction. The central wall 14 is supported by the printer main body 10a. The central wall 14 is disposed above the platen 16. A gap through which the recording medium 5 can pass is formed between the central wall 14 and the platen 16. As shown in FIG. 2, the printer 10 includes guide rails 15. The guide rails 15 extend in the main scanning direction Y. The guide rails 15 are provided on the central wall 14. The guide rails 15 are disposed above the platen 16.

[0017] As shown in FIG. 3A, the ink head unit 20 includes a first carriage 28 and a plurality of ink heads 24. The first carriage 28 engages with the guide rail 15. The first carriage 28 is configured to be movable in the main scanning direction Y along the guide rail 15. As will be described later, the first carriage 28 moves in the main scanning direction Y together with a second carriage 38 of the sensor unit 30 described later. The first carriage 28 has the ink heads 24 mounted thereon. The ink heads 24 are configured to be movable in the main scanning direction Y as the first carriage 28 moves. The ink heads 24 have a plurality of nozzles (not shown) that discharge ink onto the recording medium 5 placed on the platen 16 and are arranged in the sub-scanning direction X, and a nozzle surface 25 on which the plurality of nozzles are formed. The ink heads 24 print a predetermined image on the recording medium 5. As shown in FIG. 3A, here, five ink heads 24 are mounted on the first carriage 28. However, the number of ink heads 24 is not limited to five.

[0018] As shown in FIG. 3A, the sensor unit 30 includes a second carriage 38, a first sensor 31, a sheet cutter 33, and a second control device 90. The second carriage 38 engages with the guide rail 15. The second carriage 38 is configured to be movable in the main scanning direction Y along the guide rail 15. The second carriage 38 is detachably provided on the first carriage 28. As will be described later, the second carriage 38 moves in the main scanning direction Y together with the first carriage 28 of the ink head unit 20 or independently (i.e., independently of the first carriage 28). The second carriage 38 has the first sensor 31, the sheet cutter 33, and the second control device 90 mounted thereon. The first sensor 31 and the sheet cutter 33 are configured to be movable in the main scanning direction Y as the second carriage 38 moves.

[0019] The first sensor 31 detects the end portion of the recording medium 5 placed on the platen 16 in the main scanning direction Y (i.e., the boundary line between the recording medium 5 and the platen 16). More specifically, the first sensor 31 detects the right end 5R (see FIG. 1) and the left end 5L (see FIG. 1) of the recording medium 5. The type of the first sensor 31 is not particularly limited, and for example, a reflection type photo sensor can be mentioned. In the present embodiment, the first sensor 31 is a color sensor (typically a color sensor that detects RGB values). The first sensor 31 is connected to the second control device 90. As shown in FIG. 4, the movement locus ML of the first sensor 31 mounted on the second carriage 38 overlaps with the upstream suction hole 16HR (the upstream suction hole 16HR located in front of the groove 16D in the present embodiment) in a plan view. The mounting position of the first sensor 31 is aligned with the upstream suction hole 16HR in the sub-scanning direction X. That is, when the first sensor 31 moves in the main scanning direction Y, the first sensor 31 passes directly above the upstream suction hole 16HR.

[0020] As shown in FIG. 3A, the sheet cutter 33 is configured to be able to cut the recording medium 5 placed on the platen 16 only in the main scanning direction Y. The sheet cutter 33 is mounted on the second carriage 38. The sheet cutter 33 is configured to be movable in the vertical direction. The sheet cutter 33 is controlled by the second control device 90. When cutting the recording medium 5, the sheet cutter 33 moves along the groove 16D (see FIG. 4) formed in the platen 16.

[0021] The carriage moving mechanism 40 is a mechanism that relatively moves the first carriage 28 of the ink head unit 20 and the second carriage 38 of the sensor unit 30 in the main scanning direction Y with respect to the recording medium 5 placed on the platen 16. The carriage moving mechanism 40 moves the first carriage 28 and the second carriage 38 in the main scanning direction Y. Note that the configuration of the carriage moving mechanism 40 is not particularly limited. As shown in FIG. 1, the carriage moving mechanism 40 includes a first pulley 41, a second pulley 42, an endless belt 43, and a carriage motor 44. The first pulley 41 is provided on the left end side of the guide rail 15. The second pulley 42 is provided on the right end side of the guide rail 15. The belt 43 is wound around the first pulley 41 and the first pulley 41. The belt 43 is fixed to the upper part of the back surface of the second carriage 38 (see also FIG. 3A). The carriage motor 44 is connected to the second pulley 42. However, the carriage motor 44 may be connected to the first pulley 41. Here, when the carriage motor 44 is driven and the second pulley 42 rotates, the belt 43 runs between the first pulley 41 and the second pulley 42. As a result, the second carriage 38 moves in the main scanning direction Y. That is, the carriage motor 44 moves the second carriage 38 in the main scanning direction Y. As will be described later, the first carriage 28 moves in the main scanning direction Y as the second carriage 38 moves. The carriage motor 44 indirectly moves the first carriage 28 in the main scanning direction Y via the second carriage 38. The carriage motor 44 is controlled by the first control device 80.

[0022] As shown in Fig. 3A, a first connecting member 29 composed of a magnet is provided on the left side portion of the first carriage 28. A second connecting member 39 composed of a magnet is fixed to the right side portion of the second carriage 38. The first connecting member 29 is detachably connected to the second connecting member 39. In the present embodiment, the first connecting member 29 and the second connecting member 39 utilize magnetic force. However, the first connecting member 29 and the second connecting member 39 are not limited to those utilizing magnetic force, and may be provided with other configurations such as engaging members. On the right side of the first carriage 28, a first receiving fitting 27 formed in an L shape is provided.

[0023] As shown in Fig. 3A, a left side frame 7L and a right side frame 7R are respectively arranged to the left and right of the platen 16. A locking device 45 for locking the ink head unit 20 in the standby position is provided on the right side frame 7R. The locking device 45 includes a second receiving fitting 46 that is hooked on the first receiving fitting 27, and a locking solenoid 47 (see Fig. 6) that moves the second receiving fitting 46 between a locked position (see Fig. 3B) and an unlocked position (see Fig. 3A). The locking solenoid 47 is controlled by the first control device 80.

[0024] As shown in FIG. 3A, when a predetermined image is printed on the recording medium 5 by the ink head 24, the second receiving fitting 46 is set to the unlock position. When the second carriage 38 of the sensor unit 30 moves to the right and the second connecting member 39 contacts the first connecting member 29, the second carriage 38 and the first carriage 28 are connected. As a result, the ink head unit 20 can move in the main scanning direction Y together with the sensor unit 30. That is, when the carriage motor 44 (see FIG. 4) is driven, the first carriage 28 and the second carriage 38 move in the main scanning direction Y. On the other hand, when the end of the recording medium 5 is detected by the first sensor 31 or the recording medium 5 is cut by the sheet cutter 33, as shown in FIG. 3B, the ink head unit 20 is positioned at the standby position and the second receiving fitting 46 of the locking device 45 is set to the locked position. Thereby, the movement of the ink head unit 20 in the main scanning direction Y is blocked. When the second carriage 38 moves to the left, the second connecting member 39 and the first connecting member 29 are separated, and the connection between the second carriage 38 and the first carriage 28 is released. As a result, only the sensor unit 30 can move in the main scanning direction Y while the ink head unit 20 is waiting at the standby position. That is, when the carriage motor 44 is driven, only the second carriage 38 moves in the main scanning direction Y.

[0025] As shown in FIG. 2, the printer 10 includes a linear encoder 65. The linear encoder 65 detects the positions of the first carriage 28 and the second carriage 38. The configuration of the linear encoder 65 is not particularly limited, and for example, a photoelectric (transmission type) linear encoder can be mentioned. The linear encoder 65 has a linear scale 66 extending in the main scanning direction Y, a second sensor 67 (see FIG. 4), and a third sensor 68 (see FIG. 4). The scale 66 is provided on the central wall 14. The scale 66 is disposed above the guide rail 15. A plurality of graduations or slits arranged in the main scanning direction Y at a predetermined interval are formed on the scale 66. The second sensor 67 measures the graduations formed on the scale 66. The second sensor 67 is provided on the second carriage 38. The second sensor 67 is connected to the second control device 90 (see FIG. 3A). The second sensor 67 is arranged so as to sandwich the scale 66. Based on the graduations of the scale 66 detected by the second sensor 67, the position of the second carriage 38 can be detected. The third sensor 68 measures the graduations formed on the scale 66. The third sensor 68 is provided on the first carriage 28. The third sensor 68 is connected to the first control device 80 (see FIG. 1). The third sensor 68 is arranged so as to sandwich the scale 66. Based on the graduations of the scale 66 detected by the third sensor 68, the position of the first carriage 28 can be detected.

[0026] The media moving mechanism 55 relatively moves the recording medium 5 placed on the platen 16 in the sub-scanning direction X with respect to the first carriage 28 and the second carriage 38. The media moving mechanism 55 moves the recording medium 5 placed on the platen 16 in the sub-scanning direction X. As shown in FIG. 1, the media moving mechanism 55 includes a grit roller 57, a feed motor 58 (see FIG. 6), a pinch roller 60, and a holding shaft 64.

[0027] As shown in FIG. 1, the grit roller 57 is provided on the platen 16. The grit roller 57 is embedded in the platen 16 such that the upper part of the grit roller 57 is exposed to the outside. The grit rollers 57 are arranged in parallel in the main scanning direction Y. As shown in FIG. 4, the grit roller 57 is arranged behind the suction hole 16H (i.e., on the upstream side in the sub-scanning direction X). The grit roller 57 is arranged below the pinch roller 60. The grit roller 57 sandwiches the recording medium 5 between itself and the pinch roller 60. The feed motor 58 (see FIG. 6) is connected to the grit roller 57. The feed motor 58 is controlled by the first control device 80. That is, the grit roller 57 is controlled by the first control device 80. When the feed motor 58 is driven and the grit roller 57 rotates with the recording medium 5 sandwiched between the grit roller 57 and the pinch roller 60, the recording medium 5 is conveyed in the sub-scanning direction X.

[0028] As shown in FIG. 1, the pinch roller 60 is arranged above the platen 16. The pinch roller 60 is arranged below the guide rail 15. The pinch roller 60 is arranged at a position facing the grit roller 57. The pinch roller 60 presses the recording medium 5 placed on the platen 16 from above.

[0029] As shown in FIG. 1, the holding shaft 64 extends in the main scanning direction Y. The holding shaft 64 holds the pinch roller 60. By rotating the holding shaft 64 around its axis, the pinch roller 60 can be brought closer to or separated from the grit roller 57. The holding shaft 64 is rotatably supported by the printer main body 10a.

[0030] As shown in FIG. 1, the printer 10 includes a capping device 70. The capping device 70 is provided within the printer main body 10a. The capping device 70 is disposed to the right of the platen 16. As shown in FIG. 5, the capping device 70 includes five caps 71, a cap moving mechanism 72, and a suction pump 74. The caps 71 and the cap moving mechanism 72 are disposed at a home position HP (see FIG. 4) located at the right end portion of the guide rail 15 (see FIG. 1). Here, the home position HP is a position where at least the ink head unit 20 waits when printing is in standby, that is, when printing is not being performed. However, the position of the home position HP is not particularly limited and may be the left end portion of the guide rail 15.

[0031] The cap 71 is a member that suppresses the hardening of ink adhering to the nozzles (not shown) of the ink head 24 and the nozzle surface 25 and the clogging of the nozzles. The caps 71 are arranged in the main scanning direction Y. As shown in FIG. 5, when the first carriage 28 of the ink head unit 20 is located at the home position HP (for example, during printing standby or when the second carriage 38 moves alone), the cap 71 is attached to the ink head 24 and covers the nozzle surface 25. When the cap 71 is attached to the ink head 24, a sealed space 26 is formed between the cap 71 and the nozzle surface 25. The cap 71 is attached to the ink head 24 and forms a sealed space 26 between it and the nozzle surface 25 when the second carriage 38 of the sensor unit 30 moves alone.

[0032] The cap moving mechanism 72 supports the cap 71. The cap moving mechanism 72 is a mechanism that moves the cap 71 so as to be detachable from the ink head 24 respectively. In the present embodiment, the cap moving mechanism 72 moves the cap 71 in the vertical direction. The configuration of the cap moving mechanism 72 is not particularly limited. For example, it includes a drive motor 72A. By driving the drive motor 72A, the cap moving mechanism 72 moves the cap 71 in the vertical direction. When the first carriage 28 moves to the home position HP, the cap moving mechanism 72 moves the cap 71 upward to attach the cap 71 to the ink head 24. Also, for example, when starting printing, the cap moving mechanism 72 moves the cap 71 downward to remove the cap 71 from the ink head 24.

[0033] As shown in FIG. 5, the suction pump 74 performs a cleaning operation of sucking the fluid (for example, ink) in the sealed space 26 and discharging the ink from the nozzle (not shown) when the cap 71 is attached to the ink head 24. The suction port of the suction pump 74 is connected to the cap 71 via a flexible tube 75. The discharge port of the suction pump 74 is connected to the waste liquid tank 79. The fluid in the sealed space 26 sucked by the suction pump 74 is stored in the waste liquid tank 79. The above cleaning operation is an operation to eliminate ejection defects of the nozzle and is an operation to prevent clogging of the nozzles of the ink head 24. The suction pump 74 is controlled by the first control device 80 (see FIG. 1).

[0034] As shown in FIG. 6, the overall operation of the printer 10 is controlled by the first control device 80 and the second control device 90. The first control device 80 is connected to the second control device 90. The configurations of the first control device 80 and the second control device 90 are not particularly limited. The first control device 80 and the second control device 90 are, for example, microcomputers. Although the hardware configuration of the microcomputer is not particularly limited, for example, an interface (I / F) for receiving print data and the like from an external device such as a host computer, a central processing unit (CPU) that executes instructions of a control program, a ROM (read only memory) that stores the program executed by the CPU, a RAM (random access memory) used as a working area for developing the program, and a storage device such as a memory that stores programs and various data. As shown in FIG. 1, the first control device 80 is provided inside the printer main body 10a. However, the first control device 80 may not be provided inside the printer main body 10a. For example, the first control device 80 may be a computer installed outside the printer main body 10a. In this case, the first control device 80 is communicably connected to the printer 10 via wire or wireless. Further, the second control device 90 is mounted on the second carriage 38, but may be provided inside the printer main body 10a or may be a computer installed outside the printer main body 10a. The first control device 80 is an example of another control device, and the second control device 90 is an example of a control device.

[0035] As shown in FIG. 6, the first control device 80 is communicably connected to the ink head 24, the locking solenoid 47, the feed motor 58, the carriage motor 44, the suction pump 74, the drive motor 72A, and the third sensor 68. The first control device 80 controls the ink head 24, the locking solenoid 47, the feed motor 58, the carriage motor 44, the suction pump 74, and the drive motor 72A. That is, the first control device 80 controls the carriage movement mechanism 40, the medium movement mechanism 55, and the cap movement mechanism 72. The first control device 80 identifies the position of the first carriage 28 based on the scale of the scale 66 measured by the third sensor 68.

[0036] As shown in FIG. 6, the second control device 90 is communicably connected to the first sensor 31, the second sensor 67, and the sheet cutter 33. The second control device 90 controls the sheet cutter 33. Based on the information on the end of the recording medium 5 detected by the first sensor 31 (i.e., the measured value of the first sensor 31), the second control device 90 specifies the position of the end of the recording medium 5 (i.e., the positions of the right end 5R and the left end 5L of the recording medium 5) and the length in the main scanning direction Y of the recording medium 5 (i.e., the width of the recording medium 5). The second control device 90 specifies the position of the second carriage 38 based on the scale of the scale 66 measured by the second sensor 67. Here, when it is desired to measure more accurately the position of the end of the recording medium 5 and the length in the main scanning direction Y of the recording medium 5, it is necessary to know the measured value of the first sensor 31 and the position of the second carriage 38 simultaneously. Conventionally, when the second carriage 38 is not equipped with the second sensor 67 for specifying the position of the second carriage 38, the position of the second carriage 38 is specified from the information of the motor encoder of the carriage motor 44, and the specified information is transmitted to the first control device 80. Since the measured value of the first sensor 31 is also processed by the first control device 80, it is transmitted to the first control device 80. The first control device 80 calculates the position of the end of the recording medium 5 and the length in the main scanning direction Y of the recording medium 5 from the measured value of the first sensor 31 and the information of the motor encoder transmitted to the first control device 80. On the other hand, in the present embodiment, the first sensor 31 for acquiring the position of the end of the recording medium 5 and the second sensor 67 for acquiring the position of the second carriage 38 are communicably connected to the second control device 90. Therefore, the second control device 90 can calculate the position of the end of the recording medium 5 and the length in the main scanning direction Y of the recording medium 5 from the measured value of the first sensor 31 and the information of the second sensor 67 (the position of the second carriage 38). Thus, since the position of the end of the recording medium 5 and the length in the main scanning direction Y of the recording medium 5 are calculated by the second control device 90, the processing amount performed by the CPU of the first control device 80 can be reduced.

[0037] As described above, according to the printer 10 of the present embodiment, the second carriage 38 equipped with the first sensor 31 for detecting the end portion of the recording medium 5 in the main scanning direction Y is detachably provided on the first carriage 28 equipped with the ink head 24. Therefore, when detecting the end portion of the recording medium 5 in the main scanning direction Y by the first sensor 31, the second carriage 38 can move independently of the first carriage 28 in the main scanning direction. Here, when the second carriage 38 moves alone, a cap 71 is attached to the ink head 24, and a sealed space 26 is formed between the cap 71 and the nozzle surface 25. For this reason, the nozzles and the nozzle surface 25 are not exposed to the outside, and drying of the nozzles and the nozzle surface 25 is suppressed. Thus, when detecting the end portion of the recording medium 5 in the main scanning direction Y, since the cap 71 is attached to the ink head 24, a cleaning operation for discharging ink from the nozzles after detecting the end portion becomes unnecessary.

[0038] In the printer 10 of the present embodiment, the second control device 90 specifies the position of the end portion of the recording medium 5 and the length of the recording medium 5 in the main scanning direction Y based on the information of the end portion of the recording medium 5 detected by the first sensor 31. Thus, by detecting the end portion of the recording medium 5 in the main scanning direction Y by the first sensor 31, the position of the recording medium 5 and the length of the recording medium 5 in the main scanning direction Y can be specified.

[0039] In the printer 10 of the present embodiment, a plurality of upstream suction holes 16HR penetrating in the vertical direction and arranged in the main scanning direction Y are formed in the platen 16, and the movement locus ML of the first sensor 31 overlaps with the plurality of upstream suction holes 16HR in plan view. Since the recording medium 5 is brought into close contact with the platen 16 by the upstream suction holes 16HR, the lifting of the recording medium 5 on the platen 16 is suppressed. Here, since the first sensor 31 moves above the upstream suction holes 16HR, the end portion of the recording medium 5 in the main scanning direction Y can be detected at the position where the floating of the recording medium 5 is most reduced, and the detection accuracy becomes higher.

[0040] In the printer 10 of the present embodiment, the first sensor 31 is a color sensor, the placement surface 16A on which the recording medium 5 is placed on the platen 16 is black, and the recording medium 5 is white. In this way, since the detection accuracy with respect to the threshold value set by increasing the brightness difference can be improved, the right end 5R and the left end 5L of the recording medium 5 can be detected more accurately.

[0041] In the printer 10 of the present embodiment, a sheet cutter 33 is provided on the second carriage 38 and can cut the recording medium 5 only in the main scanning direction Y. When the recording medium 5 is cut in the main scanning direction Y by the sheet cutter 33, since the cap 71 is attached to the ink head 24, a cleaning operation for discharging ink from the nozzles after cutting the recording medium 5 becomes unnecessary.

[0042] In the printer 10 of the present embodiment, a linear encoder 65 having a linear scale 66 extending in the main scanning direction Y and a second sensor 67 provided on the second carriage 38 for measuring the scale of the scale 66 is provided. As a result, based on the measured value of the first sensor 31 and the value of the linear encoder 65 (here, the position of the second carriage 38), the position of the end of the recording medium 5 and the length of the recording medium 5 in the main scanning direction Y can be calculated by the second control device 90, so that the processing amount performed by the CPU of the first control device 80 can be reduced.

[0043] In the printer 10 of the present embodiment, the linear encoder 65 further has a third sensor 68 provided on the first carriage 28 for measuring the scale of the scale 66. Thereby, the position of the ink head 24 can be measured more accurately. That is, the landing position of the ink ejected onto the recording medium 5 becomes more accurate and the image quality is improved.

[0044] The printer 10 of the present embodiment includes a first control device 80 that controls the ink head 24 and the carriage movement mechanism 40. The second sensor 67 is connected to the second control device 90, and the second control device 90 is provided on the second carriage 38. As a result, since the position of the end of the recording medium 5 and the length in the main scanning direction Y of the recording medium 5 are calculated by the second control device 90, the processing amount performed by the CPU of the first control device 80 is reduced.

[0045] The preferred embodiments of the present invention have been described above. However, the above-described embodiments are merely examples, and the present invention can be implemented in various other forms.

[0046] A cutter capable of cutting the recording medium 5 in the main scanning direction Y and the sub-scanning direction X may be provided in the sensor unit 30 separately from the sheet cutter 33. In this case, the first sensor 31 may be configured to be able to detect crop marks printed on the recording medium. Here, the crop mark is a mark used for aligning the cutter when cutting the recording medium into a desired shape.

[0047] In the above-described embodiment, the printer 10 is provided with the first control device 80 and the second control device 90, but the first control device 80 and the second control device 90 may be integrated.

Explanation of Reference Numerals

[0048] 5 Recording medium 5L Left end 5R Right end 10 Printer (inkjet printer) 16 Platen (mounting table) 24 Ink head 25 Nozzle surface 26 Sealed space 28 First carriage 31 First sensor 38 Second carriage 40 Carriage movement mechanism 71 Cap 90 Second control device (control device)

Claims

1. A mounting table on which a recording medium is placed, an ink head having a nozzle that discharges ink onto the recording medium placed on the mounting table, and a nozzle surface on which the nozzle is formed, a first carriage on which the ink head is mounted and which is movable in the main scanning direction, a first sensor that detects an end portion of the recording medium placed on the mounting table in the main scanning direction, a second carriage that is detachably provided on the first carriage, on which the first sensor is mounted, and which is movable in the main scanning direction, a carriage moving mechanism that moves the second carriage in the main scanning direction, a cap that is detachably formed on the ink head and that covers the nozzle surface and forms a sealed space between the cap and the nozzle surface when attached to the ink head, a control device connected to the first sensor, wherein the cap is configured to be attached to the ink head to form the sealed space between the cap and the nozzle surface when the second carriage moves alone, a plurality of suction holes that are formed through the mounting table in the vertical direction and are arranged in the main scanning direction are formed in the mounting table, an inkjet printer in which a movement locus of the first sensor overlaps a plurality of the suction holes in a plan view.

2. The control device specifies a position of the end portion of the recording medium and a length of the recording medium in the main scanning direction based on information on the end portion of the recording medium detected by the first sensor. The inkjet printer according to claim 1.

3. The first sensor is a color sensor, a mounting surface of the mounting table on which the recording medium is placed is black, The recording medium is white. The inkjet printer according to claim 1 or 2.

4. The inkjet printer according to any one of claims 1 to 3, further comprising a sheet cutter that is mounted on the second carriage and that can cut the recording medium only in the main scanning direction.

5. A mounting table on which a recording medium is placed, an ink head having a nozzle that discharges ink onto the recording medium placed on the mounting table, and a nozzle surface on which the nozzle is formed, a first carriage on which the ink head is mounted and which is movable in the main scanning direction, a first sensor that detects an end portion of the recording medium placed on the mounting table in the main scanning direction, A second carriage that is detachably provided on the first carriage, on which the first sensor is mounted, and is movable in the main scanning direction; A carriage moving mechanism that moves the second carriage in the main scanning direction; A cap that is detachably formed on the ink head and forms a sealed space between the nozzle surface and the nozzle surface when attached to the ink head; A control device connected to the first sensor; Another control device that controls the ink head and the carriage moving mechanism; A linear encoder having a linear scale extending in the main scanning direction and a second sensor provided on the second carriage for measuring the scale markings; The second sensor is connected to the control device; The control device is provided on the second carriage; The cap is configured to be attached to the ink head to form the sealed space between the nozzle surface when the second carriage moves alone. An inkjet printer.

6. The inkjet printer according to claim 5, wherein the linear encoder further has a third sensor provided on the first carriage for measuring the scale markings of the scale.

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