Transfer device

Abstract

To provide a transfer device having an enhanced commercial value.SOLUTION: In the transfer section, the transfer device transfers the substance for transfer or the surface shape of the transfer web from the transfer web conveyed along the web path to the transfer object conveyed along the conveyance surface. The transfer device includes a gap adjustment mechanism that adjusts a size of a gap between the conveyance surface and the web path in the transfer section, and an ultraviolet light source unit that irradiates the web path with ultraviolet light from an irradiation position on a side opposite to the conveyance surface of the transfer object conveyance mechanism. The ultraviolet light source unit moves up and down together with the web path when the size of the gap exceeds a threshold.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a transfer device. [Background technology]

[0002] There is a known transfer device that transfers a transfer material such as foil from a transfer web transported roll-to-roll to a transfer object such as a sheet. There is also a known transfer device that performs a process called lami-coating, in which a curable coating layer applied to the surface of the transfer object is brought into close contact with the transfer web, and the surface shape formed by the unevenness of the surface of the transfer web is transferred to the coating layer, thereby transferring the surface shape of the transfer web to the transfer object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-091197 Summary of the Invention [Problem to be solved by the invention]

[0004] As a result of extensive research into transfer devices, the inventors have come to realize that in order to increase the commercial value of transfer devices, there is room for improvement in the management of the transfer section gap, which is the gap between the web path of the transfer web in the transfer section and the transport surface of the object to be transferred.

[0005] The present invention has been made in light of the above circumstances, and one exemplary purpose of an embodiment of the present invention is to provide a transfer device that has improved commercial value through appropriate management of the transfer zone gap. [Means for solving the problem]

[0006]

[0007] In order to solve the above problems, a transfer device according to one aspect of the present invention includes a web transport mechanism that transports a transfer web along a web path, a transfer object transport mechanism that transports a transfer object, an ultraviolet light source unit that irradiates ultraviolet light from an irradiation position on the opposite side of the transfer surface of the transfer object transport mechanism with respect to the web path in a transfer section where the transfer material of the transfer web or the surface shape of the transfer web is transferred to the transfer object, and a gap adjustment mechanism that adjusts a gap between the web path and the transport surface in the transfer section by raising and lowering the web path in the transfer section. The ultraviolet light source unit rises and falls together with the web path when the size of the gap exceeds a threshold value. [Effects of the Invention]

[0008] According to the present invention, a transfer device with increased commercial value can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram schematically illustrating a printing system according to an embodiment. [Figure 2] FIG. 1 is a diagram schematically illustrating a printing system according to an embodiment. [Figure 3] FIG. 2 shows a semi-hardened varnish layer. [Figure 4] FIG. 2 is a diagram showing the foil stamping device of FIG. 1. [Figure 5] FIG. 2 is a diagram showing the foil stamping device of FIG. 1. [Figure 6] 2 is an enlarged view of the foil stamping section and its surroundings of the foil stamping device of FIG. 1. FIG. [Figure 7] 5 is a diagram showing the gap adjustment mechanism and its periphery in FIG. 4. FIG. [Figure 8] 5 is a diagram showing the gap adjustment mechanism and its periphery in FIG. 4. FIG. [Figure 9] 5 is a diagram showing the gap adjustment mechanism and its periphery in FIG. 4. FIG. [Figure 10] 5 is a diagram showing the gap adjustment mechanism and its periphery in FIG. 4. FIG. [Figure 11] 11(a) to 11(f) are diagrams showing the operation of the foil stamping device in chronological order when performing foil stamping. [Figure 12] 12(a) to 12(c) are diagrams showing the operation of the foil stamping device in chronological order when performing web mounting and replacement work. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described below based on preferred embodiments with reference to the drawings. The embodiments are illustrative and do not limit the invention, and all features and combinations described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate.

[0011] Before describing the present invention in detail, an overview will be given.

[0012] The gap between the transfer web and the conveying surface of the object in the transfer section naturally needs to be large enough to allow the object to enter, but if the gap is too large, the transfer web will not come into contact with the object or the contact pressure between the transfer web and the object will be too low, and if the gap is too small, the contact pressure between the transfer web and the object will be too high, which can result in poor contact, resulting in poor transfer or poor conveyance.

[0013] In contrast, the transfer device of the present invention adjusts the size of the transfer zone gap, which is the gap between the web path of the transfer web in the transfer zone and the conveying surface of the object to a size that corresponds to the thickness of the object, thereby achieving good transfer.

[0014] Furthermore, when applying an ultraviolet-curable varnish to the transfer position of the transfer object and using the tackiness of the varnish to transfer the transfer material from the transfer web to the transfer object, it is necessary to irradiate the transfer web with ultraviolet light from the ultraviolet light source unit in the transfer section to cure the varnish. The ultraviolet light source unit irradiates ultraviolet light from a relatively close distance to the transfer web, i.e., from a distance that allows the amount of ultraviolet light required for curing to reach the transfer web. If the ultraviolet light source unit is located in this position, for example, when installing or replacing the transfer web, the transfer web must be passed through a small gap between the ultraviolet light source unit and the transfer object's conveyance surface, making the work difficult. Furthermore, it is difficult to access the small gap between the ultraviolet light source unit and the transfer object's conveyance surface, for example, when repairing a malfunctioning part or for maintenance and inspection. In other words, maintenance is difficult.

[0015] In contrast, the transfer device of the present invention can lift not only the web path of the transfer web in the transfer section but also the ultraviolet light source unit, which makes it easier to install and replace the web and perform maintenance.

[0016] Hereinafter, specific embodiments of the present invention will be described. In the following, the transfer device will be described as a foil stamping device, i.e., a device that transfers foil to a transfer object. However, the present invention is not limited to this, and the transfer device may be a device that transfers a transfer material other than foil to a transfer object. Furthermore, the transfer device may be a device that performs so-called lami-coating, which brings a curable coating layer into close contact with a transfer web to transfer the surface shape of the transfer web to the transfer object.

[0017] 1 and 2 are schematic diagrams illustrating a printing system 10 that uses a foil stamping device 16 according to an embodiment. FIG. 1 is a side view, and FIG. 2 is a plan view. The printing system 10 is an apparatus that performs a predetermined printing on a sheet while transporting the sheet. The sheet may be made of various materials, such as paper, cloth, resin, or metal. Hereinafter, the direction in which the sheet is transported (from right to left in FIGS. 1 and 2) will be referred to as the transport direction Y, and the direction perpendicular to the transport direction Y (the direction perpendicular to the paper surface in FIG. 1 and the up-down direction in FIG. 2) will be referred to as the width direction X. Furthermore, in the width direction X, the right side as viewed from the upstream side in the transport direction Y will be referred to as the right side in the width direction X, and the left side as the left side in the width direction X. Furthermore, the downstream edge of the sheet in the transport direction Y will be referred to as the leading edge of the sheet, and the upstream edge will be referred to as the trailing edge of the sheet.

[0018] Printing system 10 includes a paper feeder 12 that feeds sheets one by one, a varnishing device 14 that applies varnish to the sheets fed one by one, a foil stamping device 16 that performs foil stamping by transferring foil to the varnish on the sheet using the tackiness of the varnish, a stacker 18 that accumulates sheets, and a control device 20 that performs overall control of printing system 10. Paper feeder 12, varnishing device 14, foil stamping device 16, and stacker 18 are arranged in a line in this order from the upstream side in conveyance direction Y (the right side in Figures 1 and 2). Control device 20 is connected to paper feeder 12, varnishing device 14, foil stamping device 16, and stacker 18 via network 2.

[0019] The sheet feeding device 12 includes a feeder 22, a corona treatment unit 26, and a registration unit 24. The feeder 22 includes a table 28 and a suction head 30. Sheets are stacked on the table 28. The table 28 is configured to be able to move up and down. The suction head 30 feeds the sheets stacked on the table 28 one by one, starting from the top.

[0020] The registration unit 24 includes a registration reference guide 32 provided on one end side in the width direction X (on the right side in the width direction X in the illustrated example). The registration reference guide 32 has a guide surface 32a that is perpendicular to the width direction X and extends in the conveying direction Y. The registration unit 24 aligns the position of the sheet in the width direction X by abutting the sheet delivered by the feeder 22 against the guide surface 32a.

[0021] The corona treatment unit 26 includes an electrode 36 disposed above the transport path 34 and a dielectric roller 38 disposed below the transport path 34, facing the electrode 36 from above. The corona treatment unit 26 modifies the surface of the sheet delivered by the feeder 22 by corona discharge between the electrode 36 and the dielectric roller 38. When the sheet is transported while being attracted to the transport path 34 by the air suction unit 40, the distance between the electrode 36 and the sheet is constant, stabilizing the corona discharge. The air suction unit 40 generates negative pressure by arranging one of the suction ports of an exhaust blower (not shown). However, a suction fan may also be disposed to generate negative pressure. The dielectric roller 38 may be rotatable or fixed relative to the housing of the corona treatment unit 26. Furthermore, the shape of the dielectric roller 38 is not limited to a roller, as long as it generates corona discharge between the electrode 36 and the corona treatment unit 26. The corona treatment unit 26 may be disposed upstream of the resist unit 24.

[0022] The varnish application device 14 includes a sheet sensor 42, a pair of CCD sensors 44, at least one varnish dispenser 46, a semi-curing UV lamp 48, and a final-curing UV lamp 50. The pair of CCD sensors 44, the varnish dispenser 46, the semi-curing UV lamp 48, and the final-curing UV lamp 50 are arranged in this order from upstream to downstream. The CCD sensor 44 may be a CMOS sensor. In the illustrated example, the varnish application device 14 includes three varnish dispensers 46, but this is not limited to this. The varnish application device 14 may include one varnish dispenser 46 extending across at least the entire area required for printing in the width direction X, or two or four or more varnish dispensers 46. The semi-curing UV lamp 48 and the final-curing UV lamp 50 use LEDs that emit ultraviolet light, but other light sources that emit ultraviolet light, such as incandescent lamps or fluorescent lamps, may also be used. It is preferable that the light source have adjustable output.

[0023] The sheet sensor 42 detects the sheet fed from the sheet feeder 12 .

[0024] The varnish discharge unit 46 is a line-type inkjet head, although not particularly limited thereto. Triggered by detection of the leading edge of the sheet by the sheet sensor 42, the varnish discharge unit 46 discharges UV-curable varnish according to the varnish discharge data, applying the UV-curable varnish to the sheet. The varnish discharge data indicates where on the sheet the varnish should be applied.

[0025] A base image and a plurality of registration marks that serve as references for identifying the position of the base image may be printed in advance on the sheets fed by the paper feeder 12. The varnish applicator 14 applies varnish in a predetermined relationship with the base image according to varnish discharge data that defines the area on the sheet to be varnished; for example, the varnish may be applied so as to overlap the base image.

[0026] The sheet's base image may be misaligned or distorted. Therefore, if the varnish is to be applied so that it has a predetermined relationship with the base image, the varnish dispensed data must be corrected to account for the misalignment or distortion. For example, the CCD sensor 44 may capture an image of the sheet triggered by the sheet sensor 42's detection of the sheet. The control device 20 may then analyze the captured data from the CCD sensor 44 and correct the varnish dispensed data for the area surrounded by the registration marks based on any discrepancies between the theoretical positions of the registration marks and the actual positions. The method described in JP 2016-083898, previously filed by the applicant, may be applied to this correction.

[0027] The semi-curing ultraviolet lamp 48 irradiates the varnish on the sheet with ultraviolet light with a relatively low output, semi-curing the varnish. Semi-curing refers to curing the varnish lightly enough to reduce its fluidity but not completely (for example, to a state where it can be further cured).

[0028] The semi-cured varnish is then fully cured in the foil stamping device 16. When the sheet is not being foil stamped, the semi-curing ultraviolet lamp 48 is usually turned off or its output is set to minimum. However, the semi-curing ultraviolet lamp 48 may be used even when foil stamping is not being performed. For example, if the varnish applied to the sheet is prone to bleeding, turning on the semi-curing ultraviolet lamp 48 and leaving it to semi-cure can have the effect of preventing bleeding.

[0029] The final curing ultraviolet lamp 50 irradiates ultraviolet light onto the varnish applied to the sheet, causing the varnish to fully cure. When foil stamping (i.e., transferring foil) onto the sheet, the final curing ultraviolet lamp 50 is turned off. Although not shown, the final curing ultraviolet lamp 50 has an exhaust port for exhausting the air around it. A fan is provided in this exhaust port for generating an exhaust flow. An ozone adsorption filter for adsorbing ozone generated by ultraviolet irradiation is provided upstream of this fan in the exhaust direction, with a gap between it and the fan.

[0030] In other words, when foil stamping a sheet, the varnish is semi-cured by the semi-curing ultraviolet lamp 48, and the semi-cured varnish is fully cured by the foil stamping ultraviolet lamp 66 of the foil stamping device 16. In this case, the fully curing ultraviolet lamp 50 is turned off. When the sheet is not foil stamped, i.e., when varnish is only applied to the sheet, the varnish is fully cured by the fully curing ultraviolet lamp 50. In this case, the semi-curing ultraviolet lamp 48 and the foil stamping ultraviolet lamp 66 of the foil stamping device 16 are turned off. The semi-curing ultraviolet lamp 48 does not need to be turned off completely, and its output may be minimized. As mentioned above, the semi-curing ultraviolet lamp 48 may be turned on even when foil stamping is not being performed. Furthermore, although an LED that emits ultraviolet light is used as the light source for the foil stamping ultraviolet lamp 66, any other light source that emits ultraviolet light may be used.

[0031] 3 shows varnish layers 100, 102 that have been applied to a sheet S by a varnish discharge unit 46 and semi-cured by a semi-curing ultraviolet lamp 48. 100a, 102a are hardened portions, while 100b, 102b are uncured portions that have not yet been cured. The hardened portions 100a, 102a occupy the interior of the varnish layers 100, 102, respectively, while the uncured portions 100b, 102b occupy the surface portions of the varnish layers 100, 102, respectively. This is because the surface portions that are exposed to the outside air are more difficult to harden due to the effects of oxygen inhibition.

[0032] Both Figures 3(a) and (b) show the semi-cured state formed by suppressing the output of ultraviolet light so that the varnish layers 100 and 102 do not fully harden. However, in the case of Figure 3(a), the output of the semi-curing ultraviolet lamp 48 is relatively stronger than in the case of Figure 3(b), so the varnish layer 100 hardens closer to the surface than the varnish layer 102. Therefore, the varnish layer 100 has a more stable shape than the varnish layer 102, and although the surface layer does not flow, it is not completely hardened and has a tacky state. On the other hand, compared to the varnish layer 100, the varnish layer 102 has almost no tackiness in the surface layer and is fluid, with the fluidity of the upper portion being particularly high. Therefore, even after semi-curing, the upper portion of the varnish continues to flow, gradually flattening the top surface and creating a leveling effect.

[0033] The semi-cured varnish is then irradiated with ultraviolet light again in the final curing ultraviolet lamp 50 or foil stamping device 16, and finally cured. Final curing refers to the complete curing of all parts of the varnish layers 100, 102. In both semi-cured varnish layers 100, 102, the portions that adhere to the sheet S are mostly made up of cured portions 100a, 102a, so the adhesive joints are stable. Therefore, until the final curing, the varnish layers 100, 102 can be prevented from seeping onto the sheet S and spreading in the sheet surface direction (direction of arrow A), thereby stabilizing the shape of the sheet S in the surface direction.

[0034] The position of this semi-curing ultraviolet lamp 48 may be configured to be movable along the sheet transport direction, allowing the distance from the varnish discharge unit 46 to be adjusted. The varnish spreads from the time the varnish is applied by the varnish discharge unit 46 until it is semi-cured, resulting in a higher leveling effect. By making the distance between the semi-curing ultraviolet lamp 48 and the varnish discharge unit 46 adjustable, the timing at which the varnish stops spreading can be adjusted, allowing for a balance between leveling and shape stability. Because a thick varnish layer spreads more due to the larger volume of the varnish, it is best to move the semi-curing ultraviolet lamp 48 closer to the varnish discharge unit 46 to quickly suppress the spread of the varnish. For a thin varnish layer, it is best to move the semi-curing ultraviolet lamp 48 farther from the varnish discharge unit 46 and allow sufficient time for leveling. Furthermore, when relatively sharp characters, etc., are required, it is best to move the semi-curing ultraviolet lamp 48 closer to the varnish discharge unit 46 to quickly suppress the spread of the varnish.

[0035] The foil stamping device 16 transports a web (transfer web) 52 roll-to-roll. The web 52 is a foil-holding film in which a foil (e.g., a metal foil) is held on a film (base sheet). The foil stamping device 16 utilizes the tackiness of the semi-cured varnish on the sheet to adhere the foil held by the web 52 to the varnish. Then, with the foil held on the web 52 and adhered to the varnish on the sheet, the foil stamping ultraviolet lamp 66 irradiates the semi-cured varnish with ultraviolet light to fully cure the varnish. This results in a state in which the adhesive strength of the fully cured varnish to the foil is stronger than the strength with which the web 52 holds the foil. By separating the sheet and the web 52 in this state, the foil held on the web 52 can be transferred to the varnished portion of the sheet.

[0036] The stacker 18 accumulates the sheets discharged from the foil stamping device 16 .

[0037] The control device 20 is an information processing terminal such as a PC. The control device 20 accepts input regarding the definition of a print job. The control device 20 may display a predetermined job management screen and accept input regarding the job definition via the job management screen. The job definition includes, for example, the number of sheets to be printed (number of copies to be printed), the sheet size of the sheets to be printed, varnish data, and whether or not foil stamping is performed. The control device 20 controls the paper feed device 12, the varnish application device 14, and the foil stamping device 16 based on the job definition.

[0038] In the process of irradiating ultraviolet rays onto the sheet onto which varnish has been discharged by the varnish discharge unit 46, the control device 20 selects one of the first, second, and third modes, which differ in the combination of ultraviolet lamps used.

[0039] In the first mode, the sheet onto which varnish has been discharged by the varnish discharge unit 46 is irradiated with ultraviolet light from the semi-curing ultraviolet lamp 48 and the foil stamping ultraviolet lamp 66, and the final curing ultraviolet lamp 50 is turned off. In the second mode, the sheet onto which varnish has been discharged by the varnish discharge unit 46 is irradiated with ultraviolet light from the semi-curing ultraviolet lamp 48 and the final curing ultraviolet lamp 50, and the foil stamping ultraviolet lamp 66 is turned off. In the third mode, the sheet onto which varnish has been discharged by the varnish discharge unit 46 is irradiated with ultraviolet light only from the final curing ultraviolet lamp 50, and the semi-curing ultraviolet lamp 48 and the foil stamping ultraviolet lamp 66 are turned off.

[0040] The first mode is selected when foil stamping is performed using the foil stamping device 16. That is, when foil stamping a sheet, the varnish is semi-cured using the semi-curing ultraviolet lamp 48. The output of the semi-curing ultraviolet lamp 48 is relatively stronger than in the second mode. As shown in FIG. 3(a), the varnish layer has tackiness on the surface, which stabilizes its shape. This tackiness is utilized to adhere foil to the varnish layer in the foil stamping device 16. Because only the surface layer is uncured as shown in FIG. 3(a), even after the foil is adhered, the uncured portion is not crushed and spread in the sheet surface direction, stabilizing the shape of the varnish layer, particularly in the sheet surface direction. With the foil adhered to the varnish layer, the semi-cured varnish is fully cured using the foil stamping ultraviolet lamp 66, ensuring that the foil is reliably adhered to the varnish layer. As a result, a foil with a stable shape is obtained on the sheet after foil stamping.

[0041] The second mode is selected when foil stamping is not required. In this mode, the varnish on the sheet is semi-cured by the semi-curing ultraviolet lamp 48 and then fully cured by the final curing ultraviolet lamp 50. The sheet passes through the foil stamping device 16; foil stamping is not performed. The stacker 18 ejects the sheet with a layer of varnish formed on the portion of the sheet where the varnish is to be applied. The output of the semi-curing ultraviolet lamp 48 may be weaker than that of the first mode. As shown in Figure 3(b), the varnish layer leaves a relatively large uncured portion 102b above the surface, while the portion bonded to the sheet S is mostly cured portion 102a, resulting in a stable bond. This prevents the varnish from spreading, stabilizing its shape, and, during transport to the final curing ultraviolet lamp 50, the upper, uncured portion of the varnish flows, creating a leveling effect that flattens the top surface, resulting in a smooth varnish layer.

[0042] Furthermore, in the second mode, UV irradiation is shared between the semi-curing UV lamp 48 and the final curing UV lamp 50, so compared to the third mode, which uses a single light source for final curing, the heat radiated onto the sheet by UV rays and the heat generated during UV curing of the varnish can be dispersed more effectively. This prevents problems such as curling or other deformation of heat-sensitive sheets, discoloration of the underlying image due to heat, or melting of the toner.

[0043] The third mode is selected when foil stamping is not performed. In the third mode, the semi-curing ultraviolet lamp 48 does not semi-cure the varnish on the sheet, and only the final curing is performed by the final curing ultraviolet lamp 50. The sheet simply passes through the foil stamping device 16, and no foil stamping is performed. The sheet is discharged into the stacker 18 with a varnish layer of a predetermined shape formed in a predetermined position on the sheet. Because semi-curing is not performed, the leveling effect during transport to the final curing ultraviolet lamp 50 is improved, resulting in a varnish layer with a smoother top surface. In the third mode, the output of the semi-curing ultraviolet lamp 48 may be minimized rather than being completely turned off.

[0044] By allowing the user to select between the first, second, and third modes, an apparatus can be obtained that can form a higher quality varnish layer even when simply applying varnish to a sheet.

[0045] The control device 20 selects a mode based on the input print job definition: if the print job includes foil stamping, the first mode is selected; if the print job does not include foil stamping, the second or third mode is selected.

[0046] The varnish layer obtained in the second mode is semi-cured, which prevents the varnish layer from spreading in the direction of the sheet surface. This makes it particularly suitable for jobs that require the prevention of spreading and the stability of the shape of the varnish layer in the direction of the sheet surface.

[0047] For example, if the varnish layer is thick, the varnish spreads accordingly. Therefore, the second mode may be selected when the area includes an area where the varnish layer is thicker than a predetermined thickness. Furthermore, if the area to be varnished includes an object with a small area, or if the minimum width of the varnish layer in the sheet surface direction is narrow, or if the area includes an area with a small gap between adjacent varnish layers, the shape of the varnished area is likely to be distorted by the spreading of the varnish layer. Therefore, the second mode may be selected by image analysis of the varnish data defining the varnish application area on the sheet of the print job, and when the area of ​​the object to be varnished is less than a predetermined value, the minimum width of the varnish layer in the sheet surface direction is less than a predetermined value, or the gap between adjacent varnish layers is less than a predetermined value. Furthermore, if the print job includes a type of varnish or a type of sheet, or both, the second mode may be selected when the type of varnish or sheet is prone to spreading, or a combination of these. If these conditions for selecting the second mode are not met, the third mode, which provides excellent leveling properties, is selected. In the third mode, by minimizing the output of the semi-curing ultraviolet lamp 48 rather than turning it off completely, it is possible to obtain excellent leveling properties while slightly suppressing the spreading of the varnish, further improving the aesthetic appearance of the varnish layer.

[0048] The control device 20 may accept user input regarding which of the first, second, and third modes to select, and select the mode input by the user. Alternatively, the control device 20 may automatically select the first mode only when the print job includes foil stamping, and accept user input regarding which of the second and third modes to select when the print job does not include foil stamping. This is because, while the first mode must be selected when foil stamping is performed, there may be cases in which the second and third modes must be selected depending on the extent of spread in the actual printing. The control device 20 may display the modes selected as selection candidates using the same algorithm as in the automatic selection as recommended modes on the user input screen.

[0049] The basic configuration of the printing system 10 has been described above.

[0050] Alternatively, the printing system 10 may include a printer, instead of the paper feeder 12, that prints a base image and registration marks on the sheets, and feeds the sheets one by one from the printer.

[0051] In addition, the printing system 10 may be equipped with, between the foil stamping device 16 and the stacker 18, a post-processing device that cuts and staples sheets, a second varnishing unit to protect the foil surface, a paper inserter for surface protection, a punching machine that punches out sheets into a predetermined shape to create carton materials, etc., and a post-processing device for surface protection of paper inserts, etc.

[0052] Next, the configuration of the foil stamping device 16 will be described in detail. Figures 4 and 5 are diagrams showing the foil stamping device 16. Figure 4 is a perspective view, and Figure 5 is a side view. Figure 6 is an enlarged view of the periphery of the foil stamping section (described later).

[0053] The foil stamping device 16 includes a plurality of conveying rollers 54, an unwinding shaft 56, a winding shaft 58, a plurality of guide rollers 60, a first nip roller 62, a second nip roller 64, a foil stamping ultraviolet lamp (ultraviolet light source unit) 66, a first brake mechanism 68, a second brake mechanism 70, a gap adjustment mechanism 72, a sheet detection sensor 77, and a conveying guide 106.

[0054] The plurality of conveying rollers 54 convey the sheet downstream in the conveying direction while nipping the sheet between themselves and a paper pressure roller and nip rollers 62 and 64 (not shown).

[0055] The unwinding shaft 56 supports a roll of unused web (hereinafter referred to as unwinding roll 74). The take-up shaft 58 winds up the used web 52, i.e., the film and any foil remaining on the film, into a roll. Hereinafter, the roll of web 52 wound by the take-up shaft 58 will be referred to as the take-up roll 76.

[0056] The unwinding shaft 56 and the winding shaft 58 are configured as friction shafts. This friction shaft includes an outer ring that holds the paper tube that forms the core of the unwinding roll 74 or the winding roll 76, and a shaft core that rotatably holds the outer ring. The friction shaft is configured to adjust the holding torque, which acts as resistance when rotating the outer ring relative to the shaft core. When an external force acts to rotate the outer ring relative to the shaft core, if the rotational torque due to this external force is greater than the holding torque, the outer ring rotates relative to the shaft core. If the rotational torque is smaller than the holding torque, the outer ring remains stationary relative to the shaft core. This holding torque can be changed by adjusting the air pressure filled inside the shaft.

[0057] The friction shaft has multiple outer rings in the axial direction and is structured to allow different rotational speeds depending on their position in the axial direction (i.e., the width direction X). Specifically, only some of the outer rings may rotate while the others are stationary, or the rotating outer rings may rotate at different speeds. The outer rings have spheres on their outer periphery that move radially outward and bite into the paper tube when torque is applied in the unwinding direction of the unwinding shaft 56 or the winding direction of the winding shaft 58. When the paper tube is removed, applying torque in the reverse direction to the paper tube moves the spheres radially inward, releasing them from their engagement with the paper tube. However, if the torque applied in the reverse direction to the paper tube exceeds the holding torque, the outer rings rotate together, making it difficult for the spheres to be released and removed. To prevent this, the air pressure may be increased when removing the paper tube to strengthen the holding torque.

[0058] The unwinding shaft 56 has a holding torque set so that when a force acts to rotate the web 52 along with the sheet or the conveying roller 54 in the foil stamping section F (the section between the first nip roller 62 and the second nip roller 64) where the web 52 and the sheet come into contact, and a force acts to pull the web 52 from the unwinding roll 74, the outer ring rotates about the fixed shaft core. When transfer is not in progress, the air pressure of the unwinding shaft 56 is increased to make the holding torque larger than when transfer is in progress. The holding torque of the winding shaft 58 is set smaller than that of the unwinding shaft 56 regardless of whether transfer is in progress or not, and the shaft core of the winding shaft 58 is driven to rotate by a drive source (not shown). This prevents the web from slackening both during transfer and non-transfer.

[0059] The plurality of guide rollers 60, the first nip roller 62, and the second nip roller 64 define a generally U-shaped transport path (hereinafter referred to as the web path) for the web 52 from the unwind roll 74 to the take-up roll 76. The second nip roller 64 is adjacent to the first nip roller 62 on the downstream side of the web path. The first nip roller 62 and the second nip roller 64 define a horizontally extending section of the web path. In this embodiment, this section corresponds to the foil stamping section F.

[0060] In the foil stamping section F, the foil is transferred from the web 52 to the semi-cured varnish on the sheet. During transfer, the varnish on the sheet and the web 52 temporarily adhere to each other, so the web 52 is fed at the same speed as the sheet. Alternatively, the second nip roller 64 may be driven to rotate, so that the web 52 is fed at the same speed as the sheet. If a drive source is provided to drive the nip rollers 62, 64, and a difference in the surface movement speed occurs between the web 52 that holds the foil and the nip rollers 62, 64 and the sheet that the foil is transferred to and that contacts the conveyance roller 54, this can cause wrinkles in the foil or can cause the foil and the sheet to become misaligned in the conveyance direction between the varnish on the sheet and the web 52 after it contacts the web 52 and before the varnish hardens, resulting in poor transfer. In contrast, in this embodiment, there is no drive source for rotating the nip rollers 62, 64, and instead the nip rollers 62, 64 are configured to rotate in response to the movement of the web 52, thereby preventing wrinkles in the foil or misalignment between the foil and the sheet, which would result in poor transfer.

[0061] At least one of the guide rollers 60 is equipped with an encoder (not shown) for detecting its rotation speed. It is desirable for the guide roller 60 equipped with the encoder to minimize slippage with the web 52, for example, by using a material with a high coefficient of friction on its surface. In the foil stamping section F, the foil on the outer circumferential surface of the web 52 contacts the surface of the sheet or the conveying roller 54, and moves downstream in the sheet conveyance direction by rotating with these surfaces. The control device 20 calculates the actual moving speed of the web 52 based on the detection results from the encoder. The control device 20 further controls the rotation speed of the unwinding shaft 56, taking into account the outer diameter of the unwinding roll 74 detected by a laser sensor (not shown) or the like provided radially outside the unwinding roll 74, so that the theoretical feed speed of the web 52 from the unwinding roll 74 when the outer circumferential ring and the axial core rotate at the same speed is slower than the calculated actual moving speed of the web 52. At this time, the moving speed of the web 52 becomes faster than the unwinding speed caused by the rotation of the unwinding shaft 56, but the outer ring of the unwinding shaft 56, which is a friction shaft, rotates about an axial center portion including the drive input shaft, and the outer ring rotates faster than the drive input shaft, so that the web 52 can be unwound at the same speed as the moving speed of the sheet in the foil stamping section F while maintaining a taut state of the web 52. Note that the unwinding shaft 56 may be configured to constantly rotate at a predetermined rotational speed at which the theoretical unwinding speed of the web 52 is slower than the actual moving speed, even when the outer diameter of the unwinding roll 74 is at its largest.

[0062] Furthermore, the control device 20 controls the rotation speed of the winding shaft 58 so that the speed at which the web 52 is taken up by the winding roll 76 is faster than the moving speed of the web 52. At this time, the moving speed of the web 52 is slower than the winding speed caused by the rotation of the unwinding shaft 56, but the circumferential surface of the winding shaft 58, which is a friction shaft, rotates relative to the drive input shaft, causing the drive input shaft to spin freely relative to the circumferential surface, so that the web 52 can be taken up at the same speed as the moving speed of the sheet in the foil stamping section F while maintaining a taut state of the web 52.

[0063] The ultraviolet foil stamping lamp 66 is provided above the web path between the first nip roller 62 and the second nip roller 64. The ultraviolet foil stamping lamp 66 includes a light source (not shown) that irradiates ultraviolet light, and a light source support 98 that supports the light source. The light source support 98 is supported by a lamp stopper 104 that is fixed to the housing of the foil stamping device 16. In particular, a hook member 98a of the light source support 98 is supported by the lamp stopper 104.

[0064] The conveying guide 106 has a flat upper surface 106a, and supports the sheet with the upper surface 106a to guide the sheet.

[0065] The sheet detection sensor 77 is a sensor that detects the presence or absence of a sheet at a detection position, and based on the detection result, it is possible to detect the timing at which the leading edge and trailing edge of the sheet pass.

[0066] The gap adjustment mechanism 72 raises and lowers the first nip roller 62, the second nip roller 64, and the ultraviolet foil stamping lamp 66. The gap adjustment mechanism 72 may also raise and lower some of the guide rollers 60, for example, the guide rollers 60 adjacent to the nip rollers 62 and 64.

[0067] For example, to achieve good foil stamping, the gap adjustment mechanism 72 raises and lowers the nip rollers 62, 64 to adjust the gap G between the web path in the foil stamping section and the conveying surface to a size corresponding to the thickness of the sheet to be foil stamped. The web path in the foil stamping section may be, for example, a path connecting the lower surface (lowest part of the outer circumferential surface) of the first nip roller 62 with the lower surface (lowest part of the outer circumferential surface) of the first nip roller 62. The conveying surface may be the upper surface 106a of the conveying guide 106 or the upper surface (highest part of the outer circumferential surface) of the conveying roller 54 that faces the nip rollers 62, 64. Therefore, the size of the gap G may be the vertical distance between the nip rollers 62, 64 and the conveying roller 54 that faces the conveying guide 106 or the nip rollers 62, 64.

[0068] When the nip rollers 62, 64 are lowered, the movement path of the web 52 from the unwind roll 74 to the take-up roll 76 becomes longer. At this time, the circumferential surface rotates faster relative to the drive input shaft of the unwind shaft 56, and more of the web 52 is unwound by the amount of the movement path that has become longer. On the other hand, when the nip rollers 62, 64 are raised, the movement path of the web 52 from the unwind roll 74 to the take-up roll 76 becomes shorter. At this time, the circumferential surface rotates faster without the drive input shaft of the take-up shaft 58 spinning freely, and more of the web 52 is wound up by the amount of the movement path that has become shorter, thereby preventing the web 52 from bending.

[0069] The first brake mechanism 68 applies a brake to prevent rotation of one of the guide rollers 60 (hereinafter also referred to as guide roller 60a) that is located upstream of the first nip roller 62, and releases the brake to allow rotation. The first brake mechanism 68 is not particularly limited, but includes, for example, an electromagnetic brake provided on one end side of the guide roller 60a in the axial direction (i.e., the width direction X).

[0070] The second brake mechanism 70 applies a brake to prevent rotation of one of the guide rollers 60 (hereinafter also referred to as guide roller 60b) downstream of the second nip roller 64, or releases the brake to allow rotation. The second brake mechanism 70 is not particularly limited, but includes, for example, an electromagnetic brake provided on one axial end side of the guide roller 60b.

[0071] When the brake mechanisms 68, 70 are released, the guide rollers 60a, 60b rotate in response to the movement of the fed web 52. When the brake mechanisms 68, 70 are applied, the guide rollers 60a, 60b cannot rotate, and therefore the movement of the web 52 is braked.

[0072] In this embodiment, the winding shaft 58 rotates at a constant speed regardless of whether the sheet is passing through the stamping section F, the remaining amount of web 52, or the number of unwinding rolls 74. The rotation speed must be such that the tension of the web 52 is maintained even during foil transfer. The speed of the sheet passing through the stamping section F is constant, and therefore the speed of the web 52 in the stamping section F, which moves in conjunction with the movement of the sheet, is also constant. Therefore, the rotation speed required to maintain the tension of the web 52 increases as the diameter of the winding roll 76 decreases. Therefore, the rotation speed of the winding shaft 58 must be such that sufficient tension can be maintained even when the diameter of the winding roll 76 is minimum. On the other hand, if the diameter of the winding roll 76 is large, the torque required for winding increases, and the force pulling the foil due to inertia increases when the winding roll 76 is stopped. If there were no brake mechanism, i.e., if the movement of web 52 were braked solely by the friction torque of the friction shafts of unwinding shaft 56 and winding shaft 58, web 52 would continue to feed slightly even after the sheet has passed through the stamping section F. The fed portion would then be wound up, resulting in wasted foil. This tendency could be suppressed by lowering the rotation speed of winding shaft 58, but as mentioned above, a rotation speed sufficient to maintain tension even when winding roll 76 has its smallest diameter is required, and therefore the rotation speed cannot be lowered below that. In contrast, the presence of brake mechanisms 68, 70 allows the friction shafts and brake mechanisms 68, 70 to work together to immediately stop the feed of web 52, preventing wasted foil.

[0073] The friction force of the friction shaft of the winding shaft 58 is always constant, regardless of whether the sheet is passing through the stamping section F, the remaining amount of web 52, or the number of unwinding rolls 74. The friction shaft's strength can be adjusted mechanically, but its responsiveness is poor because the friction force is controlled by introducing air. While increasing the friction force of the friction shaft when stopping the machine is an option, it still takes time for the friction force to increase. Constantly increasing the friction force of the friction shaft may allow for instantaneous stopping, but because the winding shaft 58 is constantly rotating, excessive tension on the web 52 may result in stretching. Another option is to adjust the friction force (air pressure) of the friction shaft depending on the remaining amount of web 52. By increasing the air pressure as the remaining amount increases, problems can be prevented regardless of the remaining amount of web 52. However, if there are multiple unwinding rolls 74 with significantly different remaining amounts, increasing the air pressure to match the larger diameter unwinding rolls 74 will result in excessive tension on the smaller diameter unwinding rolls 74, causing the web 52 to stretch. In contrast, by providing brake mechanisms 68 and 70, the movement of the web is braked by an electromagnetic brake before it is wound onto the winding roll 76, so the brake is applied evenly regardless of the diameter, and the brake can be released when the foil is to be transferred. Therefore, even when there are multiple winding rolls 76, unnecessary feeding of the web 52 can be prevented.

[0074] Next, the gap adjustment mechanism 72 will be described in detail. Figures 7 to 10 are diagrams showing the gap adjustment mechanism 72 and its surroundings. Figure 7 is a perspective view, Figure 8 is a side view seen in the width direction X, and Figures 9 and 10 are side views seen from the downstream side in the conveyance direction Y. Figure 9 shows the state in which the nip rollers 62, 64 and the ultraviolet foil stamping lamp 66 have been lowered to the position for foil stamping, and Figure 10 shows the state in which the nip rollers 62, 64 and the ultraviolet foil stamping lamp 66 have been raised for web installation and replacement work. That is, [Kouji 1.1]

[0075] The gap adjustment mechanism 72 includes an electric cylinder (pressure section) 78, a nip roller support section 80, two stoppers 82, and two stepping motors 84.

[0076] The nip roller support portion 80 includes an upper frame 86, a lower frame 88, a connecting frame 90, and two blocks 92. The upper frame 86 and the lower frame 88 are spaced apart from each other in the vertical direction and extend in the width direction X so as to overlap in a plan view. The upper frame 86 is positioned above the conveying guide 106, and the lower frame 88 is positioned below the conveying guide 106. The connecting frame 90 extends in the vertical direction and connects the upper frame 86 and the lower frame 88 at one end in the width direction. The two blocks 92 are fixed to the lower surface of the upper frame 86 on the right and left sides in the width direction X, respectively. The two blocks 92 are positioned above the conveying guide 106 and support both ends of the nip rollers 62, 64 by sandwiching them between them.

[0077] The electric cylinder 78 is provided below the nip roller support portion 80. A rod 78a of the electric cylinder 78 is connected to a lower frame 88 of the nip roller support portion 80. The electric cylinder 78 raises and lowers the nip roller support portion 80 and, in turn, the nip rollers 62, 64.

[0078] The two stoppers 82 are provided on both sides in the width direction. The positions of the two stoppers 82 in the up and down direction can be adjusted independently of each other by the corresponding stepping motors 84. Specifically, the rotational driving force of the stepping motor 84 is transmitted to a drive shaft (ball screw) 96 via a transmission belt 94. When the drive shaft 96 rotates, the stoppers 82 rise or fall depending on the direction of rotation.

[0079] When nip roller support portion 80 is lowered, each of two blocks 92 comes into contact with a corresponding stopper 82 and stops, restricting further lowering of nip roller support portion 80. In other words, the vertical position of stopper 82 determines the vertical position of nip rollers 62, 64, and therefore the size of gap G.

[0080] When the nip roller support part 80 rises to a certain height, the upper surface of the upper frame 86 of the nip roller support part 80 abuts against rubber feet 108 fixed to the underside of the light source support part 98 of the ultraviolet foil stamping lamp 66. When the nip roller support part 80 rises further, the ultraviolet foil stamping lamp 66 is supported by the nip roller support part 80 and lifted. That is, the ultraviolet foil stamping lamp 66 moves away from the lamp stopper 104 and is no longer supported by the lamp stopper 104. When supported by the nip roller support part 80, the ultraviolet foil stamping lamp 66 moves up and down together with the nip roller support part 80. That is, the ultraviolet foil stamping lamp 66 in this embodiment can be retracted from an irradiation position (position in FIG. 9 ) where it irradiates ultraviolet light toward the sheet during foil stamping to a retracted position (position in FIG. 10 ) that is further away from the conveyance surface than the irradiation position and is above the irradiation position.

[0081] The control device 20 controls the electric cylinder 78 and the two stepping motors 84 to adjust the size of the gap G to a target size. Specifically, when the control device 20 wants to reduce the gap G, it controls the two stepping motors 84 to lower the two stoppers 82 to vertical positions that correspond to the target size of the gap G, and then controls the electric cylinder 78 to lower the nip roller support portion 80 so that it abuts against the stoppers 82.

[0082] Furthermore, when increasing gap G, control device 20 controls electric cylinder 78 to raise nip rollers 62, 64 to a position where gap G becomes larger than the target size, then controls two stepping motors 84 to raise two stoppers 82 to vertical positions corresponding to the size of target gap G, and then controls electric cylinder 78 to lower nip roller support portion 80 so that it abuts against stoppers 82. Note that it is possible to push up nip roller support portion 80 by raising two stoppers 82 with two stepping motors 84, but considering durability, it is preferable not to apply a load to stepping motor 84 that pushes up nip roller support portion 80.

[0083] The above is the detailed configuration of the foil stamping device 16. Next, the operation of the foil stamping device 16 will be described.

[0084] 11(a) to 11(f) are diagrams showing the operation of the foil stamping device 16 in time series when performing foil stamping (first mode).

[0085] Fig. 11(a) shows a state in which the sheet S is waiting to reach the stamping section. In Fig. 11(a), the leading edge of the sheet S has reached the sheet detection sensor 77. In Fig. 11(a), the brakes are applied by the brake mechanisms 68 and 70.

[0086] Varnish is applied to the sheet S1 and semi-cured. The sheet S1 has a leading edge non-processing area Rcf, a processing area Rc, and a trailing edge non-processing area Rcr. The leading edge non-processing area Rcf, the processing area Rc, and the trailing edge non-processing area Rcr are arranged in this order from the leading edge of the sheet S. The leading edge non-processing area Rcf and the trailing edge non-processing area Rcr are not varnished. The leading edge non-processing area Rcf is the range from the leading edge of the sheet S to the leading edge of the processing area Rc. The trailing edge non-processing area Rcr is the range from the trailing edge of the processing area Rc to the trailing edge of the sheet S. The processing area Rc is the range that includes the area where varnish is applied. If there is one area where varnish is applied, the processing area Rc is the range in the conveying direction Y from the leading edge to the trailing edge of that area. If there are multiple areas where varnish is applied, the processing area Rc is the range from the leading edge of the area whose leading edge is located furthest downstream among the multiple areas to the trailing edge of the area whose trailing edge is located furthest upstream among the multiple areas.

[0087] 11(a), the size of the gap G is adjusted to a first size G1 (for example, 3 mm). The first size is a size that prevents the web 52 from coming into contact with the sheet S even if the sheet S is present in the gap G.

[0088] FIG. 11(b) shows the state immediately before the leading edge of the processing range Rc of the sheet S enters the stamping section F. In FIG. 11(b), the size of the gap G is adjusted to a second size G2 (<first size G1). The second size G2 is the size of the gap G corresponding to the thickness of the sheet S. The second size G2 is the size that allows the sheet S to enter the gap G and allows the web 52 to contact the sheet S with an appropriate contact pressure to achieve good stamping. For example, the user may input the size of the gap corresponding to the thickness of the sheet S, and the control device 20 may acquire this as the second size G2. Alternatively, the control device 20 may calculate the second size G2 based on the thickness of the sheet S input by the user. Alternatively, the control device 20 may store correspondence information that associates various sheet thicknesses with appropriate sizes of the gap G corresponding to each of the various sheet thicknesses. For example, a sensor that acquires the sheet thickness may be provided at an appropriate position to acquire the sheet thickness, and the second size G2, which is the size of the gap G corresponding to the sheet thickness, may be determined based on the acquired sheet thickness and the correspondence information. The size of the gap G according to the thickness of the sheet may be the thickness of the sheet excluding the varnish.

[0089] The timing for adjusting the gap G from the first size G1 to the second size G2, i.e., the timing for lowering the nip rollers 62, 64, is determined by counting pulses P1 after the sheet detection sensor 77 detects the leading edge of the sheet S and receives pulses from an encoder connected to the drive mechanism of the conveying roller 54. The pulse P1 is determined based on the length of the leading edge non-processing area Rcf in the conveying direction obtained from the varnish data. The pulse P1 may be fine-tuned by a user input depending on the finishing conditions. The size of the gap G may be adjusted so that it reaches the second size G2 just before the leading edge of the sheet S enters the foil stamping area F. However, this would result in unnecessary feeding of the web 52, resulting in wasted web 52. Therefore, the size of the gap G is preferably adjusted so that it reaches the second size G2 just before the leading edge of the processing area Rc enters the foil stamping area F.

[0090] When the change in the gap G from the first size G1 to the second size G2 begins, i.e., when the nip rollers 62, 64 begin to descend, the brake applied by the first brake mechanism 68 is released. The brake applied by the second brake mechanism 70 may be released substantially simultaneously with the brake applied by the first brake mechanism 68, but is preferably released a certain time after the brake applied by the first brake mechanism 68 is released. The brake applied by the second brake mechanism 70 may be released, for example, at the moment when the state shown in FIG. 11(b) is reached. If the sheet enters the foil stamping section F while the foil is still loose in the state shown in FIG. 11(b), misalignment of the foil and the sheet in the conveying direction may occur, resulting in poor transfer at the leading edge of the processing range Rc. The braking force applied by the second brake mechanism 70 is applied at the moment the nip rollers 62, 64 descend and stop, thereby preventing the nip rollers 62, 64 from loosening due to the impact of stopping. By staggering the timing of brake release between the first brake mechanism 68 and the second brake mechanism 70, appropriate tension is applied to the foil when the leading edge of the processing range Rc enters the foil stamping section F, preventing poor transfer at the leading edge of the processing range Rc. Because the brake by the first brake mechanism 68 is released first and the brake by the second brake mechanism 70 is released later, it is possible to prevent the foil from being sent in the opposite direction when the nip rollers 62, 64 are lowered.

[0091] As the sheet S moves further and enters the foil stamping section F, the tackiness of the semi-hardened varnish causes the sheet S to adhere to the web 52, and the web 52 moves along with the sheet S moving due to the conveying rollers .

[0092] When gap G is the second size G2, control device 20 controls electric cylinder 78 to press nip roller support portion 80 against stopper 82, i.e., downward. Specifically, control device 20 controls electric cylinder 78 to continue moving nip roller support portion 80 and, therefore, nip rollers 62, 64, with a target position being a position where gap G is zero. As a result, nip roller support portion 80 is pressed toward stopper 82, and nip rollers 62, 64 are pressed downward. As a result, even when sheet S enters foil stamping section F, nip rollers 62, 64 do not move upward, maintaining gap G at second size G2, and web 52 and sheet S are in contact with each other with an appropriate contact pressure, ensuring reliable adhesion of web 52 to the sheet.

[0093] FIG. 11(c) shows the state immediately before the leading edge of the processing range Rc enters the ultraviolet irradiation range U of the foil stamping ultraviolet lamp 66. At this timing, the foil stamping ultraviolet lamp 66 starts to light up. The timing at which the lamp starts to light up is the timing at which pulse P2 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S. Pulse P2 is determined based on the length of the leading edge non-processing range Rcf in the transport direction obtained from the varnish data.

[0094] In Figure 11(d), sheet S moves while in contact with web 52. At this time, ultraviolet light is irradiated onto the semi-cured varnish on sheet S from ultraviolet foil stamping lamp 66. This irradiation completely hardens the varnish. The completely hardened varnish firmly bonds the foil on web 52 to sheet S. In Figure 11(d), web 52 has already separated near the tip of processing range Rc, but the foil remains adhered by the completely hardened varnish in the area on sheet S where varnish was applied.

[0095] Figure 11(e) shows the state immediately after the rear end of the processing area Rc leaves the irradiation range U of the ultraviolet foil stamping lamp 66. At this timing, the ultraviolet foil stamping lamp 66 is turned off. The timing of turning off the lamp is determined as the timing when pulse P3 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S. Pulse P3 is determined based on the lengths of the leading edge non-processing area Rcf and the processing area Rc in the transport direction obtained from the varnish data.

[0096] FIG. 11(f) shows the state immediately after the rear end of the processing area Rc leaves the foil stamping section F. In FIG. 11(f), the brakes are applied by the brake mechanisms 68 and 70. The size of the gap G is returned to the first size G1. The timing for returning the gap G from the second size G2 to the first size G1, i.e., the timing for raising the nip rollers 62 and 64, is the timing when pulse P4 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S. Pulse P4 is determined based on the lengths of the leading edge non-processing area Rcf and the processing area Rc in the transport direction, which are obtained from the varnish data. Because the sheet S and the web 52 separate, the movement of the web 52, which is accompanied by the movement of the sheet S, stops. The size of the gap G may be adjusted so that it becomes the first size G1 immediately after the rear end of the sheet S exits the foil stamping section F, but in this case, the web 52 will be fed unnecessarily and wasted. Therefore, preferably, the size of the gap G is adjusted so that it becomes the first size G1 immediately after the rear end of the processing range Rc exits the foil stamping section F.

[0097] The foil-stamped sheet S is discharged into the stacker 18 (see FIGS. 1 and 2), and the foil-stamping process for the sheet S is completed.

[0098] The operations in FIGS. 11(a) to 11(f) are repeated until the number of sheets specified in the job data has been processed.

[0099] Figures 12(a) to 12(c) are diagrams showing the operation of the foil stamping device 16 in chronological order when performing web loading and replacement work. In Figure 12(a), the size of the gap G is adjusted to a first size G1. From the state shown in Figure 12(a), the nip roller support part 80 (not shown in Figures 12(a) to 12(c)) and therefore the nip rollers 62, 64 are raised to increase the gap G.

[0100] In Figure 12(b), the size of the gap G is a third size G3 (>first size G1). At this time, although not shown in Figures 12(a) to 12(c), the nip roller support part 80 abuts against the rubber feet 108 of the ultraviolet foil stamping lamp 66.

[0101] When the nip roller support part 80 is further raised, the ultraviolet foil stamping lamp 66 is also raised, as shown in FIG. 12(c). In other words, when the size of the gap G is made larger than the third size G3, the ultraviolet foil stamping lamp 66 rises together with the nip rollers 62, 64. In other words, the ultraviolet foil stamping lamp 66 rises together with the web path in the foil stamping section F. Note that FIG. 12(c) shows a state in which the nip roller support part 80 and the ultraviolet foil stamping lamp 66 have risen to their highest position, and the size of the gap G is the fourth size G4 (> the third size G3). In the state shown in FIG. 12(c), web installation or replacement work, such as routing the web 52, is performed.

[0102] 12(a) after the web installation and replacement work is completed. That is, the size of the gap G is returned to the first size G1. At this time, the ultraviolet foil stamping lamp 66 descends together with the nip rollers 62, 64, i.e., along with the web path in the foil stamping section F, until the size of the gap G reaches the third size G3. When the size of the gap G reaches the third size G3, the ultraviolet foil stamping lamp 66 is supported by the lamp stopper 104 and will not descend any further.

[0103] According to this embodiment, the size of the gap G between the web path and the conveying surface in the stamping section F is adjusted to a gap according to the thickness of the sheet, which allows the web 52 and the sheet to come into contact with each other with an appropriate contact pressure, thereby achieving good stamping.

[0104] Furthermore, according to this embodiment, the nip rollers 62, 64 are pressed downward during foil stamping, and therefore even when a sheet is inserted into the gap G, the nip rollers 62, 64 do not move upward, and the size of the gap G is maintained at the second size G2, so that the web 52 and the sheet S come into contact with each other with an appropriate contact pressure, and the web 52 can be reliably adhered to the sheet.

[0105] Furthermore, according to this embodiment, the nip rollers 62, 64, that is, the web path in the stamping section F and the ultraviolet lamp 66 for stamping can be retracted upward, making it easy to install and replace the web.

[0106] Furthermore, according to this embodiment, the ultraviolet foil stamping lamp 66 can be moved up and down by the gap adjustment mechanism 72, which moves the nip rollers 62, 64 up and down to adjust the size of the gap G. This allows for a reduction in the number of drive sources compared to a case where this is not the case, and the cost of the foil stamping device 16 can be reduced.

[0107] The present invention has been described above based on an embodiment. This embodiment is merely an example, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present invention. These modifications will be described below.

[0108] In this embodiment, the web 52 moves by coming into contact with the moving sheet S, but if there is a separate drive for moving the web 52, the foil stamping ultraviolet lamp 66 may be turned off while the web 52 is stopped in accordance with the on / off timing of the drive.

[0109] Furthermore, in this embodiment, an example has been described in which one processing area Rc is formed on the sheet S. However, if the areas to be varnished are far apart at the leading and trailing ends of the sheet S, each may be treated as a separate processing area Rc, and multiple processing areas Rc may be set on one sheet, with the on / off control of the foil stamping ultraviolet lamp 66 being controlled for each processing area Rc. Specifically, the lamp may be turned on just before the leading end of the processing area Rc reaches the irradiation area U, and turned off just after the trailing end of the processing area Rc leaves the irradiation area U. This control may be performed individually for each of the multiple processing areas Rc. This shortens the time required to irradiate the sheet S with ultraviolet light, thereby suppressing defects such as deformation of the sheet S due to the heat of the ultraviolet light.

[0110] Furthermore, if the processing range Rc on the leading edge side and the processing range Rc further rearward than that are adjacent in the conveyance direction and the distance between the rear end of the leading edge processing range Rc and the front end of the rear edge processing range Rc is longer than the length of the foil stamping section F in the conveyance direction, the size of the gap G may be defined as the first gap from immediately after the rear end of the leading edge processing range Rc leaves the foil stamping section F to immediately before the front end of the rear edge processing range Rc enters the foil stamping section F. Since the web 52 is not fed and is stopped while the first nip roller 62 and the second nip roller 64 are in the first gap, it is preferable that the ultraviolet foil stamping lamp 66 be turned off after the rear end of the leading edge processing range Rc leaves the irradiation range U and before the first nip roller 62 and the second nip roller 64 rise, and then be turned on again after the first nip roller 62 and the second nip roller 64 descend and before the front end of the rear edge processing range Rc enters the irradiation range U. By doing so, the length of the web 52 to be fed can be reduced, leading to foil savings.

[0111] Furthermore, if the web 52 stops due to an emergency stop or an abnormal stop of the apparatus such as a jam, the main curing ultraviolet lamp may be immediately turned off.

[0112] Furthermore, since the ultraviolet light from the foil stamping ultraviolet lamp 66 can be tolerated for a very short time even when the web 52 is stopped, the foil stamping ultraviolet lamp 66 may be turned on or off at a timing when the irradiation time during the stopped state does not exceed a predetermined time.

[0113] Although not specifically mentioned in the embodiment, the height positions of the two stoppers 82 may be individually adjusted. For example, the two stoppers 82 may be moved to positions in the vertical direction corresponding to the thickness of the sheet, and the height positions of the two stoppers 82 may be individually fine-tuned while observing the finished product.

[0114] Furthermore, the position of the sheet in the width direction X is aligned by the registration reference guide 32, and the sheet is conveyed based on the side where the registration reference guide 32 is provided (the right side in the width direction in FIG. 2 ). Therefore, if the width dimension of the sheet is small, the sheet passes through one side in the width direction but not the other side in the width direction, which may result in a bias in the contact pressure between the web 52 and the sheet in the width direction. Therefore, the width dimension of the sheet may be input by the user or acquired by an appropriate sensor, and the height positions of the two stoppers 82 may be adjusted based on the width dimension of the sheet. For example, the control device 20 may set the height position of the stopper 82 on one side in the width direction higher than the height position of the stopper 82 on the other side in the width direction so that the gap on one side in the width direction through which the sheet passes is larger than the gap on the other side in the width direction. Furthermore, for example, when the width dimension of the sheet is equal to or smaller than a predetermined value, the control device 20 may set the gap on one side in the width direction larger than the gap on the other side in the width direction.

[0115] Furthermore, the technical concept of the embodiment is not limited to the case where foil is transferred onto a sheet, that is, the object onto which foil is transferred by the foil stamping device 16 may be something other than a sheet.

[0116] Furthermore, the web 52 that holds the foil is typically formed by vapor-depositing, coating, or attaching a metal or coloring material to a base film to create a transfer layer, which serves as the "foil" that serves as the transfer material. A release layer, adhesive layer, or other layer may be added to the transfer layer to enhance adhesion and ease of release from the base film during transfer. The long substrate sheet that supports the transfer material is not limited to a film; it may be a strip of woven fabric or other material that can hold the transfer material and transfer it to the object in the transfer zone. Meanwhile, the transfer material held by the web 52 and transferred in a transfer zone such as the foil stamping zone F is not limited to a "foil"; it may be a thin layer other than metal. It may also be an ink ribbon, where the transfer material is applied to a base web, such as ink. The long substrate sheet that supports the transfer material is not limited to a film; it may be a strip of woven fabric or other material that can hold the transfer material and transfer it to the object in the transfer zone.

[0117] Furthermore, the transfer device is not limited to a device that transfers a transfer material held by the web 52. It may also be a transfer device that performs a process known as "lami-coating," in which a web with a finely textured surface is brought into close contact with a varnish applied to the surface of a transfer object, and the texture is transferred onto the varnish surface, thereby transferring the surface shape formed by the fine texture of the web to the transfer object. Even in lami-coating, if the gap G is too large relative to the thickness of the transfer object, the contact pressure between the web and the varnish will be too low, resulting in insufficient transfer of the surface shape or no transfer at all. If the gap G is too small relative to the thickness of the transfer object, the transfer object will not fit into the gap G, or even if it does fit, the varnish will spread and distort the varnish shape. The present invention provides a transfer device that eliminates these problems and allows for proper surface shape transfer.

[0118] Furthermore, according to the present invention, the electric cylinder 78 prevents the nip rollers 62, 64 from moving upward even during transfer, maintaining a predetermined gap G, so that the surface shape of the web 52 can be reliably transferred to the varnish on the transfer target.

[0119] Any combination of the above-described embodiments and modifications is also useful as an embodiment of the present invention. A new embodiment resulting from a combination will have the combined effects of the combined embodiments and modifications. It will also be understood by those skilled in the art that the functions to be performed by each component recited in the claims can be realized by each component shown in the embodiments and modifications, either alone or in combination.

[0120] The aspects described in the claims of the present application as originally filed are recited below.

[0121] [Aspect 1] A transfer device that transfers a transfer material or a surface shape of a transfer web from a transfer web transported along a web path to a transfer target transported along a transport surface in a transfer section, comprising: a gap adjustment mechanism for adjusting the size of a gap between the transport surface and the web path in the transfer section; a control device that controls the gap adjustment mechanism to adjust the size of the gap to a size corresponding to the thickness of the transfer target; A transfer device comprising:

[0122] [Aspect 2] The transfer device according to claim 1, characterized in that the control device controls the gap adjustment mechanism so that the gap is maintained at a size corresponding to the thickness of the transfer object even when the transfer object is inserted in the gap.

[0123] [Aspect 3] rollers defining the web path in the transfer section; The transfer device described in aspect 2 is characterized in that the gap adjustment mechanism includes a stopper that positions the roller at a position corresponding to the thickness of the object to be transferred by regulating the movement of the roller toward the conveying surface, and a pressing portion that presses a support portion that supports the roller against the stopper.

[0124] [Aspect 4] 4. The transfer device according to any one of aspects 1 to 3, wherein the gap adjustment mechanism is capable of individually adjusting the gap at two locations in the width direction.

[0125] [Aspect 5] a registration reference guide provided at one end in the width direction and contacting the transferred object transported to the transfer section to position the transferred object in the width direction; The transfer device described in aspect 4 is characterized in that the control device controls the gap adjustment mechanism so that one end side of the gap in the width direction is larger than the other end side when the width dimension of the transferred object is equal to or smaller than a predetermined dimension.

[0126] [Aspect 6] an ultraviolet light source unit that irradiates ultraviolet light from an irradiation position on the opposite side of the transport surface with respect to the web path in the transfer section; 6. The transfer device according to any one of aspects 1 to 5, wherein the ultraviolet light source unit is retractable from the irradiation position to a retracted position that is farther from the transport surface than the irradiation position.

[0127] [Aspect 7] 7. The transfer device according to claim 6, wherein the ultraviolet light source unit is movable between the irradiation position and the retracted position by the gap adjustment mechanism.

[0128] [Aspect 8] the gap adjustment mechanism adjusts the size of the gap by raising and lowering the web path in the transfer section; When the size of the gap is equal to or smaller than a threshold value, the ultraviolet light source unit is not supported by the gap adjustment mechanism and is maintained at the irradiation position without raising or lowering the web path; A transfer device according to aspect 7, wherein when the size of the gap exceeds a threshold value, the ultraviolet light source unit is supported by the gap adjustment mechanism and moves up and down together with the web path.

[0129] [Aspect 9] a sensor capable of detecting the arrival of an object to be transferred being transported to the transfer section; The transfer device described in aspect 8 is characterized in that the control device controls the gap adjustment mechanism to adjust the gap to a gap larger than the gap corresponding to the thickness of the transfer object and smaller than the threshold value until the sensor detects the arrival of the transfer object, and when the sensor detects the arrival of the transfer object, adjusts the gap to a gap corresponding to the thickness of the transfer object.

[0130] [Aspect 10] a first roller and a second roller that define the web path in the transfer section; The first roller is disposed so that its axial direction coincides with the width direction, the second roller is disposed so that its axial direction coincides with the width direction, and the web path in the transfer section defined between the second roller and the first roller is parallel to the conveying surface; 10. The transfer device according to any one of aspects 1 to 9, wherein the gap adjustment mechanism adjusts the size of the gap by adjusting the vertical positions of the first and second rollers.

[0131] [Aspect 11] a web transport mechanism for transporting the transfer web along a web path; a transfer object transport mechanism for transporting a transfer object; an ultraviolet light source unit that irradiates ultraviolet light from an irradiation position on the opposite side of the transfer surface of the transfer object transport mechanism with respect to the web path in a transfer section where the transfer material of the transfer web or the surface shape of the transfer web is transferred to the transfer object; a gap adjustment mechanism that adjusts a gap between the web path in the transfer section and the conveying surface by raising and lowering the web path in the transfer section, The transfer device is characterized in that the ultraviolet light source unit rises and falls together with the web path when the size of the gap exceeds a threshold value. [Explanation of symbols]

[0132] 10 printing system, 16 foil stamping device, 52 web, 60 guide roller, 62 first nip roller, 64 second nip roller, 72 gap adjustment mechanism, F foil stamping section, G gap, S sheet.

Claims

1. a web transport mechanism for transporting the transfer web along a web path; a transfer object transport mechanism for transporting a transfer object; an ultraviolet light source unit that irradiates ultraviolet light from an irradiation position on the opposite side of the transfer surface of the transfer object transport mechanism with respect to the web path in a transfer section where the transfer material of the transfer web or the surface shape of the transfer web is transferred to the transfer object; a gap adjustment mechanism that adjusts a gap between the web path in the transfer section and the conveying surface by raising and lowering the web path in the transfer section, The transfer device is characterized in that the ultraviolet light source unit rises and falls together with the web path when the size of the gap exceeds a threshold value.

2. 2. The transfer device according to claim 1, wherein the ultraviolet light source unit is moved up and down by the gap adjustment mechanism.

3. the gap adjustment mechanism adjusts the size of the gap by raising and lowering the web path in the transfer section; When the size of the gap is equal to or smaller than a threshold value, the ultraviolet light source unit is not supported by the gap adjustment mechanism and is maintained at the irradiation position without raising or lowering the web path; 3. The transfer device according to claim 2, wherein when the size of the gap exceeds a threshold value, the ultraviolet light source unit is supported by the gap adjustment mechanism and moves up and down together with the web path.

4. 4. The transfer device according to claim 1, further comprising a control device that controls the gap adjustment mechanism to adjust the size of the gap to a size corresponding to the thickness of the transfer target.

5. a sensor capable of detecting the arrival of an object to be transferred being transported to the transfer section; The transfer device according to claim 4, characterized in that the control device controls the gap adjustment mechanism to adjust the gap to a gap larger than the gap corresponding to the thickness of the transfer object and smaller than the threshold value until the sensor detects the arrival of the transfer object, and when the sensor detects the arrival of the transfer object, adjusts the gap to a gap corresponding to the thickness of the transfer object.

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