Printing device

Abstract

To provide a printer which can perform a stable inspection of a base material by facilitating tension control.SOLUTION: In a printer, a cooling drive roller 51 is provided on the upstream of an imaging unit 85. The cooling drive roller 51 can cool a transparent base material M. With this, the temperature rise equal to or greater than a prescribed value causing the imaging defect of the imaging unit 85 is prevented and therefore the stability of an inspection can be kept. Moreover, the conveyance force is prevented from being given to the transparent base material M, a cooling driven roller being a driven roller having a cooling function has such a possibility that it is difficult to perform the tension control of the transparent base material M, the expansion and contraction amount of the base material does not become stable and the inspection is not correctly performed. The cooling drive roller 51 has a cooling function in the roller itself and can give the conveyance force to the base material while controlling the rotational speed of the roller, thus enabling the stable and correct inspection of the base material while properly performing the tension control of the base material.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a printing device that prints images such as characters and figures on a long substrate. [Background technology]

[0002] A conventional printing device includes a printing unit, a drying unit, and an image acquisition unit (an imaging unit and an illumination unit). The printing unit includes an inkjet head. The head ejects ink onto a transparent substrate. The drying unit dries the ink by blowing hot air. The image acquisition unit captures a print image. A defect inspection is performed based on the captured print image (see, for example, Patent Document 1).

[0003] Also, a cooling mechanism is provided between the drying section and the image acquisition section (scanner) in the transport path of the print medium (see, for example, Patent Document 2). The cooling mechanism includes a plurality of cooling driven rollers (cooling rollers). The plurality of cooling driven rollers cool the print medium. Each cooling driven roller is configured such that a cooling medium such as water is supplied from a cooling medium supply device to one end of the rotating shaft, and is discharged from the other end and returned to the cooling medium supply device (see, for example, Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-142007 A [Patent Document 2] JP 2020-011396 A [Patent Document 3] JP 2018-122525 A Summary of the Invention [Problem to be solved by the invention]

[0005] When the substrate, still heated in the drying section, is transported to the image acquisition section (imaging section and lighting section), the following three problems occur. If the imaging section is, for example, a CIS (contact image sensor), imaging becomes impossible if the temperature of the CIS rises to 70°C or higher (point 1). The amount of light decreases as the temperature of the lighting section rises, and even for the same pattern, the imaging results differ, resulting in a drop in inspection quality (point 2). Depending on the type and pattern of substrate, the amount of expansion and contraction of the substrate due to temperature differs, which can lead to false detection (point 3).

[0006] Therefore, multiple cooling driven rollers are installed between the drying section and the imaging section, which makes it possible to keep the temperature of the imaging section itself and the temperature of the base material near the imaging section constant and to suppress imaging failures and erroneous detection to some extent from the viewpoint of the influence of temperature.

[0007] However, since a coolant such as water is supplied to each cooling driven roller, the cooling driven roller may be heavy, which increases the inertia and rotational resistance of each cooling driven roller, making it difficult to control the tension of the substrate, and the amount of expansion and contraction of the substrate may become unstable, making it difficult to perform the inspection accurately.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a printing device that makes it easy to control tension and enables stable inspection of substrates. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention has the following configuration: That is, a printing device according to the present invention includes a printing unit that applies ink to a substrate, a drying unit that is provided downstream of the printing unit in the substrate transport direction and that dries the ink applied to the substrate using heat, and an imaging unit that is provided downstream of the drying unit in the substrate transport direction and that images the substrate. a conveying roller that is provided downstream of the drying unit in a conveying direction of the base material and that guides the base material vertically upward; and an illumination unit that irradiates the light so that the light passes through the base material and is incident on the imaging unit; a drying unit located downstream in a conveying direction of the base material and an imaging unit; and the conveying rollera first drive roller provided upstream of the imaging unit in the transport direction of the substrate and having a function of applying a transport force to the substrate and cooling the substrate; and a second drive roller provided downstream of the imaging unit in the transport direction of the substrate and applying a transport force to the substrate, the first drive roller including a roller body around which the substrate is wound, an electric motor that rotates the roller body, a coupling that connects a first end of the roller body to the electric motor, a rotary joint that is connected to a second end of the roller body so as to be rotatable around a horizontal axis, and a rotary joint that rotates the rotary joint. a supply pipe arranged to pass through the rotary joint and supply a cooling medium to the inside of the roller body, and a discharge pipe arranged to pass through the rotary joint and collect the cooling medium from the inside of the roller body, the supply pipe extending along the horizontal axis to the first end side, and inside the roller body, the supply pipe is formed with a plurality of discharge ports along the horizontal axis, each of the plurality of discharge ports opening upward, and the plurality of discharge ports discharge the cooling medium so that the discharged cooling medium reaches an upper inner wall of the roller body. The imaging unit and the illumination unit are disposed so as to face each other across the base material conveyed vertically upward by the conveying rollers in the horizontal direction. It is characterized by the above.

[0010] According to the printing device of the present invention, a first driving roller is provided upstream of the imaging unit. The first driving roller can cool the substrate. This prevents the temperature from rising above a predetermined value, which causes poor imaging in the imaging unit, and as a result, the stability of the inspection can be maintained. In addition, a cooling driven roller, which is a driven roller that does not apply a conveying force to the substrate and has a cooling function, makes it difficult to control the tension of the substrate, and the amount of expansion and contraction of the substrate may not be stable, resulting in an inaccurate inspection. In the present invention, a first driving roller with a cooling function is provided. In this configuration, the roller itself has a cooling function, and the rotation speed of the roller can be controlled to apply a conveying force to the substrate, so that a stable and accurate inspection of the substrate can be performed while appropriately controlling the tension of the substrate.

[0011] In addition, since the first drive roller is provided upstream of the imaging unit and the second drive roller is provided downstream of the imaging unit, the tension acting on the substrate passing through the imaging unit is easy to control. In other words, the tension acting on the substrate passing through the imaging unit is not affected by the load from the roller group upstream of the first drive roller. Therefore, since it is easy to control the tension acting on the substrate passing through the imaging unit (tension control by the second drive roller), it is possible to suppress a decrease in inspection accuracy due to the expansion and contraction of the substrate.

[0012] In the printing apparatus described above, an example of the first driving roller is that a cooling medium is supplied to the inside of the first driving roller, thereby cooling the substrate. The first driving roller can cool the substrate by the cooling medium supplied to the inside of the first driving roller.

[0013] In addition, in the above-mentioned printing device, one example of the first drive roller is that the first drive roller includes a blower unit, and the blower unit blows gas toward the wound portion of the substrate wrapped around the first drive roller, thereby cooling the substrate. The first drive roller can cool the substrate by the gas from the blower unit blown toward the wound portion of the substrate. A printing device according to the present invention includes a printing unit that deposits ink on a substrate, a drying unit that is provided downstream of the printing unit in a transport direction of the substrate and that dries the ink deposited on the substrate by using heat, and an imaging unit that is provided downstream of the drying unit in the transport direction of the substrate and that images the substrate. a conveying roller that is provided downstream of the drying unit in a conveying direction of the base material and that guides the base material vertically upward; and an illumination unit that irradiates the light so that the light passes through the base material and is incident on the imaging unit; a drying unit located downstream in a conveying direction of the base material and an imaging unit; and the conveying rollera first drive roller provided upstream of the imaging unit in the transport direction of the substrate and having a function of applying a transport force to the substrate and cooling the substrate; and a second drive roller provided downstream of the imaging unit in the transport direction of the substrate and applying a transport force to the substrate, the first drive roller including an air blowing unit and a roller body around which the substrate is wound, the air blowing unit being disposed on the opposite side of the roller body across the substrate wound around the roller body, the air blowing unit blowing gas toward a wound portion of the substrate wound around the roller body to cool the substrate. The imaging unit and the illumination unit are disposed so as to face each other across the base material conveyed vertically upward by the conveying rollers in the horizontal direction. It is characterized by the above. According to the printing device of the present invention, a first driving roller is provided upstream of the imaging unit. The first driving roller can cool the substrate. This prevents the temperature from rising above a predetermined value, which causes poor imaging in the imaging unit, and as a result, the stability of the inspection can be maintained. In addition, a cooling driven roller, which is a driven roller that does not apply a conveying force to the substrate and has a cooling function, makes it difficult to control the tension of the substrate, and the amount of expansion and contraction of the substrate may not be stable, resulting in an inaccurate inspection. In the present invention, a first driving roller with a cooling function is provided. In this configuration, the roller itself has a cooling function, and the rotation speed of the roller can be controlled to apply a conveying force to the substrate, so that a stable and accurate inspection of the substrate can be performed while appropriately controlling the tension of the substrate. In addition, since the first drive roller is provided upstream of the imaging unit and the second drive roller is provided downstream of the imaging unit, the tension acting on the substrate passing through the imaging unit is easy to control. In other words, the tension acting on the substrate passing through the imaging unit is not affected by the load from the roller group upstream of the first drive roller. Therefore, since it is easy to control the tension acting on the substrate passing through the imaging unit (tension control by the second drive roller), it is possible to suppress a decrease in inspection accuracy due to the expansion and contraction of the substrate. Furthermore, the first drive roller can cool the substrate by the gas from the blower that is blown toward the wound portion of the substrate.

[0014] In addition, the printing device described above preferably further includes a cleaner that is disposed downstream of the first driving roller in the transport direction of the substrate and upstream of the imaging unit in the transport direction of the substrate, and that removes dust adhering to the substrate. This allows the imaging unit to capture an image in a state where dust has been removed by the cleaner. This makes it possible to prevent a printed portion from being determined to be defective due to dust.

[0015] In the above-mentioned printing device, it is preferable that the second drive roller is disposed above the first drive roller, the imaging unit is disposed at a higher position than the first drive roller, and the second drive roller is disposed at a higher position than the imaging unit. In this way, the base material is transported so as to rise from the bottom to the top in the transport path between the first drive roller and the second drive roller. As a result, the footprint of the printing device can be reduced.

[0016] In the printing device described above, it is preferable that the imaging unit is configured with a contact image sensor, which prevents the temperature of the contact image sensor from rising above a predetermined value, which may cause imaging failure, and as a result, the stability of the inspection can be maintained. Effect of the Invention

[0017] According to the printing device of the present invention, it becomes easier to control the tension of the substrate, and it is possible to perform stable and accurate inspection of the substrate. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of a printing device according to an embodiment. [Diagram 2] FIG. 2 is a diagram showing an inspection block and a winding mechanism according to the embodiment. [Diagram 3] FIG. 1A is a diagram showing a cooling drive roller, and FIG. 1B is a view taken along the line AA in FIG. [Figure 4] FIG. 1 shows two cleaners. [Diagram 5]FIG. 2 is a diagram showing two conveying rollers and an inspection unit. [Figure 6] 13A and 13B are diagrams illustrating a cooling drive roller according to a modified example. EXAMPLES

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic diagram of a printing device 1 according to the embodiment. Fig. 2 is a diagram showing an inspection block 7 and a winding mechanism 12 according to the embodiment.

[0020] (1) Configuration of Printer 1 Referring to Fig. 1, the printing apparatus 1 includes a coating unit 2, a printing block 3, a drying block 5, an inspection block 7, a payout mechanism 11, and a winding mechanism 12. The payout mechanism 11, the coating unit 2, the printing block 3, the drying block 5, the inspection block 7, and the winding mechanism 12 are arranged in a horizontal line in this order.

[0021] "Upstream" means the upstream of the transport path (or transport direction) along which the long transparent substrate M is transported. Moreover, "downstream" means the downstream of the transport path (or transport direction).

[0022] The printing device 1 transports a long (or long strip-shaped) transparent substrate (or transparent print medium) M in a roll-to-roll manner from a payout mechanism 11 to a winding mechanism 12. The transparent substrate M is made of a resin film such as OPP (oriented polypropylene) or PET (polyethylene terephthalate). In this embodiment, of both sides of the transparent substrate M, the side on which an image is printed is called the printing side F1, and the side opposite the printing side F1 is called the back side F2.

[0023] The coating unit 2 applies a coating liquid to the transparent substrate M being transported. Thereafter, the printing block 3 ejects ink by an inkjet method onto the transparent substrate M being transported in order to form an image on the transparent substrate M. The drying block 5 dries the ink adhering to the transparent substrate M being transported. The inspection block 7 inspects for defects on the image printed on the transparent substrate M being transported.

[0024] The printer 1 includes a control unit 14 and a storage unit (e.g., a memory) not shown. The control unit 14 includes a central processing unit (CPU). The control unit 14 controls each component of the printer 1 (e.g., the inspection block 7 and the winding mechanism 12). The storage unit stores programs necessary for the operation of the printer 1.

[0025] (1-1) Configuration of application unit 2 The coating unit 2 includes a drive roller 16, a plurality of conveying rollers 18, a pan 21, and a gravure roller 23. The drive roller 16 is disposed on the entrance side of the coating unit 2. The drive roller 16 takes in the transparent substrate M from the unwinding mechanism 11. The drive roller 16 and the plurality of conveying rollers 18 are supported rotatably around a horizontal axis in the Y direction. The drive roller 16 is driven by an electric motor. Each conveying roller 18 is not connected to the rotating shaft of the electric motor, and is a roller that does not apply a conveying force to the transparent substrate M. Each conveying roller 18 guides the transparent substrate M. The pan 21 stores a liquid primer (coating liquid).

[0026] The lower part of the gravure roller 23 is partially immersed in the primer stored in the pan 21. The upper part of the gravure roller 23 contacts the transparent substrate M being transported. The gravure roller 23 is driven by an electric motor. The gravure roller 23 rotates in a direction opposite to the transport direction of the transparent substrate M. When the gravure roller 23 rotates, the primer is held on the outer circumferential surface of the gravure roller 23, and the held primer is transferred to the transparent substrate M. In this way, the primer is applied to the printing surface F1 of the transparent substrate M. The transparent substrate M to which the primer has been applied is sent to the printing block 3.

[0027] (1-2) Configuration of Printing Block 3 The printing block 3 includes a plurality of transport rollers 18, a color printing unit 31, a first drying unit 32, a white printing unit 33, and a second drying unit 34. The color printing unit 31, the first drying unit 32, the white printing unit 33, and the second drying unit 34 are arranged in this order along the transport path of the transparent substrate M.

[0028] The color printing unit 31 includes, for example, six (plural) ejection heads 41. The six ejection heads 41 are arranged along the transport path of the transparent substrate M. Furthermore, the six ejection heads 41 and an ejection head 43, which will be described later, are each arranged so as to cross the transparent substrate M in the width direction (Y direction) of the transparent substrate M. The six ejection heads 41 eject ink of a color other than white by an inkjet method. The six ejection heads 41 eject ink of, for example, cyan, magenta, yellow, black, blue, and orange, respectively. As a result, a color image is formed on the printing surface F1 of the transparent substrate M.

[0029] The first drying section 32 includes a plurality of nozzles 42 arranged along the transport path. The plurality of nozzles 42 and a plurality of nozzles 44, 48 described later each have a longitudinal outlet in the Y direction. The outlets of the plurality of nozzles 42 and the plurality of nozzles 44, 48 described later are arranged so as to cross the transparent substrate M in the width direction (Y direction) of the transparent substrate M. Each of the plurality of nozzles 42 sprays air at room temperature that is generated by, for example, an electric fan. This dries the six colors of ink attached to the printing surface F1 of the transparent substrate M.

[0030] The white printing unit 33 includes one ejection head 43. The ejection head 43 ejects white ink by an inkjet method. As a result, a white image is formed on the printing surface F1 of the transparent substrate M.

[0031] The second drying section 34 includes a plurality of nozzles 44 arranged along the transport direction. Each of the plurality of nozzles 44 sprays air at room temperature, which is generated by, for example, an electric fan. This dries the white ink adhering to the printing surface F1 of the transparent substrate M. The transparent substrate M that has passed through the second drying section 34 is transported to the drying block 5.

[0032] (1-3) Configuration of Drying Block 5 The drying block 5 includes, for example, three (multiple) stages of drying paths DP1 to DP3, a plurality of transport rollers 18, two air turn bars 46, and a drying section 47. Each of the two air turn bars 46 ejects air from an ejection port (not shown). The two air turn bars 46 can turn the transparent substrate M without contact. The three stages of drying paths DP1 to DP3 are arranged in the vertical direction, and are composed of an upper stage drying path DP1, a middle stage drying path DP2, and a lower stage drying path DP3. That is, within the drying block 5, the transparent substrate M is transported in an S-shape.

[0033] A specific description will be given. The transparent substrate M is transported along the upper drying path DP1 in the forward direction XF from the printing block 3 to the inspection block 7, and is turned back by the two transport rollers 18. Thereafter, the transparent substrate M is transported along the middle drying path DP2 in the reverse direction XB from the inspection block 7 to the printing block 3, and is turned back without contact by the two air turn bars 46. Thereafter, the transparent substrate M is transported along the lower drying path DP3 in the forward direction XF. A drying section 47 is provided in each of the three drying paths DP1 to DP3. The drying section 47 includes a plurality of nozzles 48. The plurality of nozzles 48 sprays air (hot air) generated, for example, by an electric fan and heated, for example, to 80° C. by a heater. The plurality of nozzles 48 sprays the hot air onto the printing surface F1 of the transparent substrate M. This causes the transparent substrate M to be further dried. The transparent substrate M that has passed through the three drying paths DP1 to DP3 is transported to the inspection block 7.

[0034] (1-4) Configuration of inspection block 7 Next, the inspection block 7, which is a characteristic feature of the present invention, will be described with reference to FIG.

[0035] The inspection block 7 includes a plurality of conveying rollers 18, a cooling drive roller 51, a first cleaner 53, a second cleaner 54, a sensor 55, an encoder roller ER, an inspection unit 57, a tension detection roller 58, an inspection downstream drive roller 59, a dancer roller 61, and nip rollers 63 and 64. The nip roller 63 is disposed such that the nip roller 63 and the cooling drive roller 51 sandwich the transparent substrate M. The rollers such as the plurality of conveying rollers 18, the cooling drive roller 51, and the inspection downstream drive roller 59 are supported rotatably around a horizontal axis in the Y direction.

[0036] The cooling drive roller 51 corresponds to the first drive roller of the present invention. The inspection downstream drive roller 59 corresponds to the second drive roller of the present invention.

[0037] FIG. 3(a) is a diagram showing the cooling drive roller 51. FIG. 3(b) is a cross-sectional view seen from the direction of the arrow AA in FIG. 3(a). The cooling drive roller 51 is provided downstream of the drying section 47 (drying block 5) and transmits a conveying force to the transparent substrate M and cools the transparent substrate M. The cooling drive roller 51 includes a roller body 71, an electric motor 72, a rotary joint 73, a liquid supply pipe 74, a liquid discharge pipe 75, and a coupling 76. As shown in FIG. 3(b), the diameter DM1 of the outer circumferential surface of the cylindrical cooling drive roller 51 is larger than the diameter DM2 of the outer circumferential surface of the conveying roller 18.

[0038] The roller body 71 includes a storage portion 71A, a rotating shaft 71B, and a hollow shaft 71C. The storage portion 71A is formed in the internal space of the cylindrical roller body 71. The rotating shaft 71B is provided on a circular side surface CS1 at a first end of the roller body 71.

[0039] The hollow shaft 71C is provided on the circular side surface CS2 of the second end of the roller body 71. The hollow shaft 71C is formed in a tubular shape. Therefore, the inside of the hollow shaft 71C serves as an entrance and exit for the storage section 71A. One end of the rotary joint 73 is inserted into the inside of the hollow shaft 71C. As a result, the rotary joint 73 closes the inside of the hollow shaft 71C and the storage section 71A, and is connected to the hollow shaft 71C so as to be rotatable around the horizontal axis AX1.

[0040] Coupling 76 connects rotating shaft 72A of electric motor 72 and rotating shaft 71B of roller body 71. Therefore, when rotating shaft 72A of electric motor 72 rotates, roller body 71 rotates. Also, hollow shaft 71C rotates integrally with roller body 71. In contrast, rotary joint 73, liquid supply pipe 74, and liquid discharge pipe 75 are fixed and do not rotate integrally with roller body 71, hollow shaft 71, etc.

[0041] Liquid supply pipe 74 and liquid discharge pipe 75 are disposed so as to penetrate rotary joint 73. One end of liquid supply pipe 74 and one end of liquid discharge pipe 75 pass through hollow shaft 71C and are disposed in storage section 71A. Liquid supply pipe 74 extends along horizontal axis AX1 until close to rotation shaft 71B. A plurality of discharge ports 74A are formed in liquid supply pipe 74 disposed inside storage section 71A. The plurality of discharge ports 74A are disposed in a row along horizontal axis AX1. Each of the plurality of discharge ports 74A opens upward. A discharge port 75A is formed at one end of liquid discharge pipe 75.

[0042] A cooling water circulation mechanism (not shown) supplies cooling water (also called constant temperature water) to liquid supply pipe 74. The cooling water is adjusted to 20°C to 25°C. The cooling water is discharged upward from a plurality of discharge ports 74A. The discharged cooling water reaches upper inner wall 71D. In FIG. 3(a), the cooling water is stored in storage section 71A to, for example, about half the capacity of storage section 71A. In this regard, the cooling water may be stored in storage section 71A so as to fill almost the entire capacity of storage section 71A. The amount of cooling water in storage section 71A may be set arbitrarily. The cooling water in storage section 71A is collected in liquid discharge pipe 75 through discharge port 75A. The collected cooling water is supplied again to liquid supply pipe 74 by the cooling water circulation mechanism.

[0043] Returning to FIG. 2, the two cleaners 53 and 54 are provided downstream of the cooling drive roller 51. The first cleaner 53 removes dust adhering to the printing surface F1 of the transparent substrate M. The second cleaner 54 removes dust adhering to the back surface F2 of the transparent substrate M opposite the printing surface F1. The second cleaner 54 removes dust at a position on the transport path of the transparent substrate M different from the first cleaner 53. That is, as shown in FIG. 4, the position where the first cleaner 53 removes dust is defined as position P1, and the position where the second cleaner 54 removes dust is defined as position P2. In this case, position P1 is different from position P2.

[0044] 4 is a diagram showing two cleaners 53 and 54. The two transport rollers 18A and 18B transport the transparent substrate M in an S-shape. The transparent substrate M is wrapped around the transport roller 18A so that the transport roller 18A comes into contact with the back surface F2. The transparent substrate M is wrapped around the transport roller 18B so that the transport roller 18B comes into contact with the printing surface F1.

[0045] The first cleaner 53 removes dust adhering to the printing surface F1 of the transparent substrate M in the portion wrapped around the transport roller 18A. The second cleaner 54 removes dust adhering to the back surface F2 of the transparent substrate M in the portion wrapped around the transport roller 18B.

[0046] The first cleaner 53 includes a removing roller 81 and an adhesive roller 82. The removing roller 81 and the adhesive roller 82 are each disposed so as to cross the transparent substrate M in the width direction of the transparent substrate M. The removing roller 81 is formed of a flexible material such as rubber. The transport rollers 18A and 18B are formed of metal. That is, the removing roller 81 is made of a material that is softer than the transport rollers 18A and 18B. The transport roller 18A rotates around a horizontal axis AX2. The removing roller 81 rotates around a horizontal axis AX3. The adhesive roller 82 rotates around a horizontal axis AX4.

[0047] The removing roller 81 is in line contact with the transparent substrate M. The adhesive roller 82 is in line contact with the removing roller 81. As the transparent substrate M is transported, the transport roller 18A and the removing roller 81 rotate, and further, the adhesive roller 82 with which the removing roller 81 is in contact rotates. When the removing roller 81 rotates, the removing roller 81 removes dust adhering to the printing surface F1 of the transparent substrate M. That is, dust is adhered to the removing roller 81 by the adhesive force of the removing roller 81. Then, the dust adhered to the removing roller 81 is transferred to the adhesive roller 82. In this way, the first cleaner 53 removes dust adhering to the printing surface F1.

[0048] As shown in Fig. 4, the second cleaner 54 is configured similarly to the first cleaner 53. The second cleaner 54 removes dust adhering to the back surface F2. The adhesive roller 82 is configured from a roll-shaped adhesive sheet such as an adhesive tape. The adhesive sheet to which the dust has been transferred is peeled off and cut to expose a new adhesive surface.

[0049] Return to FIG. 2. A sensor 55 is provided downstream of the second cleaner 54. Furthermore, an encoder roller ER is provided downstream of the sensor 55. The sensor 55 is composed of a contrast sensor, for example, an image sensor such as a CCD (charge-coupled device) or CMOS, a CIS (contact image sensor), a photoelectric sensor, or a laser sensor. The sensor 55 detects the leading mark of each page printed by the color printing unit 31 from the back surface F2 side. For example, when the sensor 55 is a contrast sensor, the contrast sensor detects the presence or absence of the leading mark by the amount of reflected light. The sensor 55 also detects the leading mark at the portion wrapped around the conveying roller 18B. The encoder roller ER detects the moving distance of the transparent substrate M. The encoder roller ER includes, for example, a rotary encoder. The control unit 14 (see FIG. 1) can calculate the distance between the detected leading mark and the imaging unit 85, for example, based on the leading mark detected by the sensor 55 and the moving distance detected by the encoder roller ER.

[0050] The two conveying rollers 18C, 18D and the inspection unit 57 are provided downstream of the encoder roller ER. The conveying roller 18C is disposed at a higher position than the two cleaners 53, 54, and guides the transparent substrate M vertically upward. The inspection unit 57 performs defect inspection of the printed portion by imaging the transparent substrate M from the back surface F2. The reason for imaging from the back surface F2 side is that the white ink is printed last, so the image cannot be correctly recognized. In addition, the surface seen by the consumer is the back surface F2. As shown in FIG. 5, the inspection unit 57 includes an imaging unit 85 and an illumination unit 86. The imaging unit 85 and the illumination unit 86 are disposed so as to face each other across the transparent substrate M conveyed vertically upward by the conveying roller 18C in the horizontal direction.

[0051] That is, the imaging unit 85 faces horizontally toward the illumination unit 86, and the illumination unit 86 faces horizontally toward the imaging unit 85. In addition, a front surface 85F of the imaging unit 85 is disposed along the vertical direction, and a front surface 86F of the illumination unit 86 is disposed along the vertical direction.

[0052] The imaging unit 85 is, for example, configured with a CIS (contact image sensor), which is a type of line sensor. When the imaging unit 85 is configured with a CIS, the imaging unit 85 includes, for example, an imaging element 87, two light sources 88A, 88B, and an equal-magnification imaging lens (not shown). The two light sources 88A, 88B are arranged along the conveying direction. The imaging element 87 is arranged between the two light sources 88A, 88B. Each of the two light sources 88A is, for example, configured with an LED (light emitting diode). The imaging element 87 is, for example, configured with a CMOS image sensor. The light irradiated from the two light sources 88A, 88B is reflected by the transparent base material M and enters the imaging element 87.

[0053] The illumination unit 86 includes a light source 86A such as an LED. The light source 86A emits white light. The light emitted from the illumination unit 86 passes through a transparent substrate M and enters the imaging element 87. The illumination unit 86 may allow light emitted from the light source 86A and reflected by a reflector to enter the imaging element 87. A diffusion plate is provided on a front surface 85F of the illumination unit 86 as necessary.

[0054] The tension detection roller 58 is provided downstream of the two conveying rollers 18C, 18D and the inspection section 57. The inspection downstream drive roller 59 is provided downstream of the tension detection roller 58. The tension detection roller 58 is provided with, for example, a strain gauge and detects the tension of the transparent substrate M. The tension detected by the tension detection roller 58 is used for tension control of the conveying path between the cooling drive roller 51 and the inspection downstream drive roller 59. The inspection downstream drive roller 59 is driven by an electric motor. The inspection downstream drive roller 59 is a drive roller disposed next to the cooling drive roller 51. The nip roller 64 is disposed so that the nip roller 64 and the inspection downstream drive roller 59 sandwich the transparent substrate M. The dancer roller 61 is provided downstream of the inspection downstream drive roller 59.

[0055] The control unit 14 (see FIG. 1) controls the tension of the transparent substrate M between the cooling drive roller 51 and the inspection downstream drive roller 59 to a preset value, for example, by operating the inspection downstream drive roller 59 based on the tension detected by the tension detection roller 58. In other words, the control unit 14 controls the tension between the two drive rollers 51, 59 to be constant.

[0056] Refer to FIG. 2. In the transport path between the cooling drive roller 51 and the inspection downstream drive roller 59 of the inspection block 7, the transparent substrate M is transported so as to rise from the bottom to the top. A specific description will be given. The inspection block 7 includes two drive rollers (cooling drive roller 51, inspection downstream drive roller 59). The inspection downstream drive roller 59 is provided above the cooling drive roller 51. In addition, the two cleaners 53, 54 are disposed at a higher position than the cooling drive roller 51. The transport roller 18C is disposed at a higher position than the two cleaners 53, 54. The inspection unit 57 (imaging unit 85 and illumination unit 86) is disposed at a higher position than the transport roller 18C. The inspection downstream drive roller 59 is disposed at a higher position than the inspection unit 57. By configuring in this way, it is possible to reduce the footprint of the inspection block 7, i.e., the printing device 1. The transparent substrate M is transported to the winding mechanism 12.

[0057] (1-5) Configuration of winding mechanism 12 The winding mechanism 12 includes a plurality of conveying rollers 18, a winding roller 91, and a splicer 93. The winding roller 91 is driven by an electric motor. The winding roller 91 is provided downstream of the inspection downstream drive roller 59. The winding roller 91 is also disposed at a lower position than the inspection downstream drive roller 59. That is, the winding mechanism 12 lowers the transparent substrate M that has been conveyed so as to rise from the bottom to the top in the inspection block 7.

[0058] The splicer 93 is disposed along the transport path from the inspection downstream drive roller 59 to the winding roller 91. The splicer 93 is disposed above the winding roller 91. Specifically, the splicer 93 is disposed vertically above the half of the roll RL of the transparent substrate M wound around the winding roller 91 on the inspection block 7 side. The splicer 93 is disposed at a lower position than the inspection downstream drive roller 59.

[0059] The splicer 93 is used to cut and join the transparent substrate. The splicer 93 corresponds to the work table of the present invention. In the transport path between the cooling drive roller 51 and the inspection downstream drive roller 59, the transparent substrate M is transported so as to rise from the bottom to the top. Therefore, it is necessary to lower the transparent substrate M to the winding roller 91. At this time, the transparent substrate M passes through the splicer 93, which is located above the winding roller 91 and lower than the inspection downstream drive roller 59. This makes it possible to reduce the footprint of the printing device 1 while transporting the transparent substrate M so as to descend from the inspection downstream drive roller 59 to the winding roller 91.

[0060] (2) Operation of the printing device Next, a brief description will be given of the operation of the printing device 1, in particular the operation of the inspection block 7 and the winding mechanism 12. The drying section 47 of the drying block 5 shown in FIG. 1 blows hot air from a plurality of nozzles 48 onto the transparent substrate M to dry the ink adhering to the transparent substrate M. Therefore, the transparent substrate M from which the ink has been dried by the drying section 47 is heated. The heated transparent substrate M is transported to the inspection block 7.

[0061] Please refer to FIG. 2. The heated transparent substrate M is transported to the cooling drive roller 51. The cooling drive roller 51 cools the transparent substrate M. This prevents the temperature from rising above a predetermined value that may cause imaging failure in the imaging unit 85, and as a result, the stability of the inspection can be maintained. Thereafter, the transparent substrate M is transported to two cleaners 53, 54. The two cleaners 53, 54 remove dust adhering to both sides (printing surface F1 and back surface F2) of the transparent substrate M.

[0062] Thereafter, the transparent substrate M is conveyed to the sensor 55 and the encoder roller ER in this order. The sensor 55 detects the leading mark of each page. The encoder roller ER measures the conveying distance of the transparent substrate M. After being conveyed to the encoder roller ER, the transparent substrate M is conveyed to two conveying rollers 18C, 18D and the inspection section 57 (imaging section 85 and illumination section 86). The conveying roller 18C guides the transparent substrate M vertically upward. The imaging section 85 and the illumination section 86 are arranged to face each other with the transparent substrate M conveyed vertically upward by the conveying roller 18C sandwiched between them in the horizontal direction. This makes it difficult for dust to adhere to the front surface 85F of the imaging section 85 and the front surface 86F of the illumination section 86. Therefore, imaging failures due to dust can be prevented.

[0063] The imaging unit 85 captures the print image from the back surface F2. A defect inspection is performed based on the data of the captured print image. Since dust adhering to the transparent substrate M is removed near the imaging unit 85, the encoder roller ER, and the sensor 55, it is possible to prevent a defect caused by dust from being determined.

[0064] After being transported to the inspection section 57, the transparent substrate M is transported to the inspection downstream drive roller 59 and the dancer roller 61 in this order. Thereafter, the transparent substrate M is transported to the splicer 93. The splicer 93 is a workbench. An operator can cut or join the transparent substrate M at the splicer 93. The winding roller 91 winds up the transparent substrate M that has passed through the splicer 93.

[0065] According to this embodiment, a cooling drive roller 51 is provided upstream of the imaging unit 85. The cooling drive roller 51 can cool the transparent substrate M. This prevents a temperature rise above a predetermined value that would cause poor imaging by the imaging unit 85, and as a result, the stability of the inspection can be maintained. In addition, a cooling driven roller, which is a driven roller that does not apply a conveying force to the transparent substrate M and has a cooling function, may make it difficult to control the tension of the transparent substrate M, and the amount of expansion and contraction of the substrate may not be stable, resulting in an inaccurate inspection. The cooling drive roller 51 of this embodiment has a cooling function for cooling the transparent substrate M, and can apply a conveying force to the transparent substrate M by controlling the rotation speed of the roller. Therefore, it is possible to perform a stable and accurate inspection of the substrate while appropriately controlling the tension.

[0066] In addition, since the cooling drive roller 51 is provided upstream of the imaging unit 85 and the inspection downstream drive roller 59 is provided downstream of the imaging unit 85, the tension acting on the transparent substrate M passing through the imaging unit 85 is easily controlled. In other words, the tension acting on the transparent substrate M passing through the imaging unit 85 is not affected by the load from the conveying rollers 18 located upstream thereof, including the cooling drive roller 51. Therefore, since the tension acting on the transparent substrate M passing through the imaging unit 85 is easily controlled (tension control by the inspection downstream drive roller 59), it is possible to suppress a decrease in inspection accuracy due to expansion and contraction of the transparent substrate M.

[0067] Furthermore, the inspection block 7 is provided downstream of the cooling drive roller 51 in the transport direction of the transparent substrate M and upstream of the inspection unit 57 in the transport direction of the transparent substrate M, and includes two cleaners 53, 54 that remove dust adhering to the transparent substrate M. This allows the inspection unit 57 to perform inspection in a state where dust has been removed by the two cleaners 53, 54. This allows the inspection unit 57 to prevent the printing portion from being determined to be defective due to dust.

[0068] Furthermore, in the inspection block 7, the inspection downstream drive roller 59 is disposed above the cooling drive roller 51. The imaging unit 85 is disposed at a higher position than the cooling drive roller 51. The inspection downstream drive roller 59 is disposed at a higher position than the imaging unit 85. As a result, the transparent substrate M is transported so as to rise from the bottom up in the transport path between the cooling drive roller 51 and the inspection downstream drive roller 59. As a result, the footprints of the inspection block 7 and the printing device 1 can be reduced.

[0069] The present invention is not limited to the above-described embodiment, but can be modified as follows.

[0070] (1) The cooling drive roller 51 of the above embodiment is configured to be supplied with cooling water. In this regard, the cooling medium supplied to the inside of the cooling drive roller 51 is not limited to water, and may be, for example, oil. Moreover, the cooling medium is not limited to liquid, and may be gas.

[0071] (2) In the above-described embodiment and modification (1), the inspection block 7 includes a cooling drive roller 51. The cooling drive roller 51 may include an air blower 101 to improve cooling capacity. In FIG. 6, two air blowers 101 are provided. In this regard, one air blower 101 may be provided, or three or more air blowers 101 may be provided.

[0072] The two air blowing units 101 are arranged along the transport direction of the transparent substrate M. Each air blowing unit 101 includes a fan 102 and a nozzle 103. The fan 102 is driven by an electric motor. The nozzle 103 has an outlet that is elongated in the Y direction. The outlet is arranged to cross the transparent substrate M in the width direction (Y direction) of the transparent substrate M. Each air blowing unit 101 cools the transparent substrate M by blowing gas toward the wound portion of the transparent substrate M wound around the cooling drive roller 51 (roller body 71).

[0073] When the cooling drive roller 51 includes the air blowing section 101 shown in FIG. 6, the cooling drive roller 51 may have a configuration in which no cooling medium is supplied thereto, if necessary.

[0074] (3) In the above-described embodiment and each modified example, the imaging unit 85 is configured with a CIS. In this regard, the imaging unit 85 may be a line camera sensor. The line camera sensor includes, for example, a CCD image sensor. The line camera sensor may also include two light sources that irradiate from the upstream and downstream of the CCD image sensor.

[0075] (4) In the above-described embodiment and each modified example, as shown in FIG. 4, the second cleaner 54 removes dust at a position different from that of the first cleaner 53. In this regard, the second cleaner 54 may remove dust at the same position as that of the first cleaner 53. In this case, a predetermined position of the transparent substrate M is sandwiched between two removing rollers 81 of the two cleaners 53, 54.

[0076] (5) In the above-described embodiment and each modified example, each of the two cleaners 53, 54 is a contact type cleaner. In this regard, at least one of the two cleaners 53, 54 may be a non-contact type cleaner. For example, the first cleaner 53 may generate ultrasonic waves to remove dust adhering to the transparent substrate M. Also, the first cleaner 53 may eject gas from a nozzle to remove dust adhering to the transparent substrate M.

[0077] (6) In the above-described embodiment and each modified example, the color printing unit 31 ejects six colors of ink, but is not limited to six colors of ink. For example, the color printing unit 31 may eject four colors of ink: cyan, magenta, yellow, and black. In other words, the color printing unit 31 may eject a plurality of colors of ink. The color of the ink may be set to any color other than white.

[0078] (7) In the above-described embodiment and each modified example, the first cleaner 53 removes dust adhering to the printed surface F1 (first surface), and the second cleaner 54 removes dust adhering to the reverse surface F2 (second surface). In this respect, the roles may be reversed. That is, the first cleaner 53 may remove dust adhering to the reverse surface F2 (first surface), and the second cleaner 54 may remove dust adhering to the printed surface F1 (second surface).

[0079] (8) In the above-described embodiment and each modified example, in the transport path other than between the two drive rollers 51, 59, at least one of the multiple transport rollers 18 may be replaced with a drive roller 16 driven by an electric motor.

[0080] (9) In the above-described embodiment and each modified example, the printing device 1 prints an image on a transparent substrate M. In this regard, the printing device 1 may print an image on a non-transparent substrate. In this case, the illumination unit 86 of the inspection unit 57 may not be provided. The printing device 1 may also print an image on continuous paper. In this case, the printing device 1 may not be provided with the coating unit 2.

[0081] (10) In the above-described embodiment and each modified example, the printing block 3 ejects ink onto the transported transparent substrate M by an inkjet method in order to form an image on the transparent substrate M, but the method is not limited to the inkjet method. For example, the printing block 3 may apply ink to the transparent substrate M by offset printing or gravure printing. [Explanation of symbols]

[0082] 1 … Printing device 3 … Printing block 5 … Drying block 7 … Inspection block 14 ... Control section 18 ... Transport roller 31 … Color printing section 33 … White printing section 47 … Drying section 48 ... Nozzle 51 ... Cooling drive roller 53 … 1st cleaner 54 ... Second cleaner 57 … Inspection Department 59 … Inspection downstream drive roller 81 ... Removal roller 82 ... Adhesive roller 85 … Imaging section 86 … Lighting department M…Transparent base material

Claims

1. a printing section for applying ink to the substrate; a drying section that is provided downstream of the printing section in a transport direction of the substrate and that dries the ink attached to the substrate by using heat; an imaging section that is provided downstream of the drying section in a transport direction of the substrate and captures an image of the substrate; a conveying roller that is provided downstream of the drying section in a conveying direction of the base material and guides the base material vertically upward; an illumination unit that irradiates the light so that the light passes through the base material and enters the imaging unit; a first drive roller that is provided downstream of the drying unit in the transport direction of the substrate and upstream of the imaging unit and the transport roller in the transport direction of the substrate, the first drive roller having a function of applying a transport force to the substrate and cooling the substrate; a second drive roller that is provided downstream of the imaging unit in a conveying direction of the base material and applies a conveying force to the base material; Equipped with The first drive roller is a roller body around which the base material is wound; an electric motor for rotating the roller body; a coupling connecting a first end of the roller body and the electric motor; a rotary joint rotatably connected to the second end of the roller body about a horizontal axis; a supply pipe disposed to pass through the rotary joint and supplying a cooling medium to an inside of the roller body; a discharge pipe disposed to pass through the rotary joint and configured to collect a cooling medium from inside the roller body; The supply pipe extends along the horizontal axis toward the first end, Within the roller body, the supply pipe is formed with a plurality of discharge ports along the horizontal axis, Each of the plurality of outlets opens upward, the plurality of outlets discharge the cooling medium so that the discharged cooling medium reaches an upper inner wall of the roller body; A printing apparatus, characterized in that the imaging unit and the illumination unit are arranged to face each other across the base material transported vertically upward by the transport rollers in the horizontal direction.

2. 2. The printing device according to claim 1, A printing apparatus, wherein the first drive roller cools the base material by supplying a cooling medium therein.

3. 3. The printing device according to claim 1, A printing device characterized in that the first drive roller is equipped with an air blowing section, and the air blowing section blows gas toward the wrapped portion of the substrate wrapped around the first drive roller, thereby cooling the substrate.

4. a printing section for applying ink to the substrate; a drying section that is provided downstream of the printing section in a transport direction of the substrate and that dries the ink attached to the substrate by using heat; an imaging section that is provided downstream of the drying section in a transport direction of the substrate and captures an image of the substrate; a conveying roller that is provided downstream of the drying section in a conveying direction of the base material and guides the base material vertically upward; an illumination unit that irradiates the light so that the light passes through the base material and enters the imaging unit; a first drive roller that is provided downstream of the drying unit in the transport direction of the substrate and upstream of the imaging unit and the transport roller in the transport direction of the substrate, the first drive roller having a function of applying a transport force to the substrate and cooling the substrate; a second drive roller that is provided downstream of the imaging unit in a conveying direction of the base material and applies a conveying force to the base material; Equipped with the first drive roller includes a blower and a roller body around which the base material is wound; the air blowing section is disposed on the opposite side of the roller body across the base material wrapped around the roller body, the blower blows gas toward a wound portion of the base material wound around the roller body to cool the base material; A printing apparatus, characterized in that the imaging unit and the illumination unit are arranged to face each other across the base material transported vertically upward by the transport rollers in the horizontal direction.

5. 5. The printing device according to claim 1, A printing device characterized in that it further comprises a cleaner that is provided downstream of the first drive roller in the transport direction of the substrate and upstream of the imaging unit in the transport direction of the substrate, and removes debris adhering to the substrate.

6. 6. The printing device according to claim 1, the second drive roller is disposed above the first drive roller, the imaging unit is disposed at a position higher than the first driving roller, The printing apparatus, wherein the second drive roller is disposed at a position higher than the imaging unit.

7. 7. The printing device according to claim 1, The printing device according to claim 1, wherein the imaging unit is composed of a contact image sensor.

Images