Web detection device

Abstract

To provide a technology that can improve usability of a printing system equipped with a foil stamping apparatus.SOLUTION: A web detection device includes a sensor, and a control device that determines an actual existence range Rw within a possible existence range Rmax in the width direction of a web 52 conveyed roll-to-roll based on detection results of the sensor.SELECTED DRAWING: Figure 8

Description

[Technical field]

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

[0002] A printing system is known that includes a varnish application device that applies varnish to a sheet, and a foil stamping device that transfers foil from a web transported by roll-to-roll to the varnish on the sheet. For example, a foil stamping device as described in Patent Document 1 has been proposed as an example of the foil stamping device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-276472 A Summary of the Invention [Problem to be solved by the invention]

[0004] 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 technique for improving the usability of a printing system equipped with a foil stamping device. [Means for solving the problem]

[0005] In order to solve the above problems, a web detection device according to one embodiment of the present invention includes a sensor and a control unit that determines the actual presence range of a web transported roll-to-roll within a possible presence range in the width direction based on the detection results of the sensor. Effect of the Invention

[0006] According to the present invention, the usability of a printing system equipped with a foil stamping device can be improved. [Brief description of the drawings]

[0007] [Figure 1]FIG. 1 is a diagram illustrating a printing system according to an embodiment. [Diagram 2] FIG. 1 is a diagram illustrating a printing system according to an embodiment. [Diagram 3] FIG. 2 shows a semi-cured varnish layer. [Figure 4] FIG. 2 is a perspective view of the foil stamping device of FIG. 1. [Diagram 5] FIG. 2 is a side view of the foil stamping device of FIG. [Figure 6] FIG. 2 is a side view of the foil stamping device of FIG. [Figure 7] FIG. 2 is a plan view of the foil stamping device of FIG. [Figure 8] 2 is a plan view showing the foil stamping device of FIG. 1 and a sheet being conveyed toward the foil stamping device. [Figure 9] 5A and 5B are diagrams illustrating an example of a detection result by a first sensor. [Figure 10] 11 is a diagram showing an example of a detection result by a second sensor. FIG. [Figure 11] 11(a) and 11(b) are diagrams showing an example of a determination scene by the control device. [Figure 12] 12(a) to 12(d) are diagrams showing other examples of the determination scene by the control device. [Figure 13] 13(a) to (d) are diagrams showing the time sequence of the foil stamping operation. [Figure 14] 14(a) to (d) are diagrams showing the time sequence of the foil stamping operation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] 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 given the same reference numerals, and duplicated descriptions are omitted as appropriate.

[0009] 1 and 2 are schematic diagrams showing a printing system 10 in which a web detection device according to an embodiment is used. 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. Hereinafter, the direction in which the sheet is transported (direction from right to left in FIGS. 1 and 2) is called the "transport direction," and the direction perpendicular to the transport direction (direction perpendicular to the paper surface in FIG. 1, and the up-down direction in FIG. 2) is called the "width direction." In addition, the downstream edge of the sheet or a predetermined range on the sheet in the "transport direction" is called the "leading edge," and the upstream edge is called the "rear edge."

[0010] The printing system 10 includes a sheet 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 transfers foil to the varnish on the sheet by utilizing the tackiness of the varnish, a stacker 18 that accumulates the sheets, and a control device 20 that controls the printing system 10 in an integrated manner. The sheet feeder 12, the varnishing device 14, the foil stamping device 16, and the stacker 18 are arranged in a line in this order from the upstream side in the conveying direction (the right side in Figs. 1 and 2). The control device 20 is connected to the sheet feeder 12, the varnishing device 14, the foil stamping device 16, and the stacker 18 via a network 2. The web detection device is composed of the control device 20 and the first sensor 68 and the second sensor 70 of the foil stamping device 16, which are among the components of the printing system 10.

[0011] The sheet feeding device 12 includes a feeder 22, a registration unit 24, and a corona treatment unit 26. 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 capable of ascending and descending. The suction head 30 feeds the sheets stacked on the table 28 one by one in order from the top.

[0012] The registration unit 24 aligns the widthwise position of the sheet fed by the feeder 22 by abutting against a registration reference guide 32 .

[0013] 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 so as to face the electrode 36 from above and below. The corona treatment unit 26 modifies the surface of the sheet by corona discharge between the electrode 36 and the dielectric roller 38. When the sheet is transported in a state where it is attracted to the transport path 34 by the air suction unit 40, the distance between the electrode 36 and the sheet becomes constant, and corona discharge becomes stable. The air suction unit 40 is one of the suction ports of an exhaust blower (not shown) that generates negative pressure, but it may be configured to generate negative pressure by arranging a suction fan. The dielectric roller 38 may be rotatable or fixed with respect to the housing of the corona treatment unit 26. Furthermore, the shape of the dielectric roller 38 is not limited to a roller shape as long as it generates corona discharge between the electrode 36 and the sheet.

[0014] The varnish application device 14 includes a sheet sensor 42, a pair of CCD sensors 44, a varnish discharge section 46, a semi-curing ultraviolet lamp 48, and a final curing ultraviolet lamp 50. The pair of CCD sensors 44, the varnish discharge section 46, the semi-curing ultraviolet lamp 48, and the final curing ultraviolet lamp 50 are arranged in this order from the upstream side. The CCD sensor 44 may be a CMOS sensor. In the illustrated example, the varnish application device 14 includes three varnish discharge sections 46, but is not limited to this, and the varnish application device 14 may include one varnish discharge section 46 extending across the entire width direction, or may include two or four or more varnish discharge sections 46. The semi-curing ultraviolet lamp 48 and the final curing ultraviolet lamp 50 use LEDs that irradiate ultraviolet rays, but may be other light sources such as light bulbs and fluorescent lamps as long as they irradiate ultraviolet rays. The light source is capable of adjusting the output.

[0015] The sheet sensor 42 detects the sheet fed from the sheet feeder 12 .

[0016] The varnish discharge unit 46 is a line-type inkjet head, although there is no particular limitation. The varnish discharge unit 46 is triggered by detection of the leading edge of the sheet by the sheet sensor 42, and discharges ultraviolet-curable varnish according to the varnish data to apply the ultraviolet-curable varnish to the sheet. The varnish data is data that indicates where on the sheet the varnish is to be applied.

[0017] A base image and a plurality of registration marks serving as a reference for identifying the position of the base image may be printed in advance on the sheet fed by the paper feeder 12. The varnishing device 14 applies varnish so as to have a predetermined relationship with the base image according to varnish data that defines the portion of the sheet to be varnished, and may apply varnish so as to overlap the base image, for example.

[0018] Here, the base image of the sheet may be misaligned or distorted. Therefore, when applying varnish so as to have a predetermined relationship with the base image, it is necessary to correct the varnish data taking into account the misalignment or distortion. For example, the CCD sensor 44 may capture an image of the sheet triggered by the detection of the sheet by the sheet sensor 42, and the control device 20 may perform image analysis of the captured data by the CCD sensor 44, and correct the varnish data of the area surrounded by the registration marks based on the difference from the theoretical positions of the multiple registration marks. For this correction, the method described in JP 2016-083898 A, previously filed by the applicant, may be applied.

[0019] The semi-curing ultraviolet lamp 48 irradiates the varnish on the sheet with ultraviolet light with a relatively reduced output to semi-cure the varnish. Semi-curing refers to curing the varnish lightly (for example, to a state where it can be further cured) to a degree that reduces the fluidity of the varnish but does not completely cure it.

[0020] 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. 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 be semi-cured has the effect of suppressing bleeding.

[0021] The main curing ultraviolet lamp 50 irradiates the varnish applied to the sheet with ultraviolet light to main cure the varnish. When foil stamping is performed on the sheet, the main curing ultraviolet lamp 50 is turned off.

[0022] That is, 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, that is, 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. As described above, the semi-curing ultraviolet lamp 48 may be turned on even when foil stamping is not performed. In addition, although an LED that irradiates ultraviolet light is used as the light source of the foil stamping ultraviolet lamp 66, other light sources that irradiate ultraviolet light may be used.

[0023] 3 is a diagram showing varnish layers 100, 102 that have been applied onto a sheet S by a varnish discharge unit 46 and semi-cured by a semi-curing ultraviolet lamp 48. 100a, 102a are cured portions, and 100b, 102b are uncured portions that are not sufficiently cured. The cured 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 exposed to the outside air are more difficult to cure due to the effects of oxygen inhibition.

[0024] 3(a) and (b) are both semi-cured layers formed by suppressing the output of ultraviolet light so that the varnish layers 100 and 102 are not completely cured. In the case of FIG. 3(a), the output of the semi-curing ultraviolet lamp 48 is relatively stronger than in the case of FIG. 3(b), so the varnish layer 100 is cured 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 cured and has a tacky state. On the other hand, compared to the varnish layer 100, the varnish layer 102 has almost no tackiness at the surface and has a high fluidity, especially in the upper part. Therefore, even after semi-curing, the upper varnish flows, gradually exerting a leveling effect in which the upper surface becomes flat.

[0025] The semi-cured varnish is irradiated with ultraviolet light again in the final curing ultraviolet lamp 50 or the foil stamping device 16, and is fully cured. Full curing refers to all parts of the droplets 100, 102 being completely cured. For both droplets 100, 102 in the semi-cured state, the parts that are adhered to the sheet S are mostly hardened parts 100a, 102a, so the adhesion parts are stable. Therefore, until the final curing, the droplets 100, 102 can be prevented from seeping onto the sheet S and spreading in the sheet surface direction (in the direction of arrow A), and the shape of the sheet S in the surface direction is stabilized.

[0026] The position of the semi-curing ultraviolet lamp 48 may be configured to be movable along the sheet conveying direction, and the distance from the varnish discharge section 46 may be adjustable. The varnish spreads from the application of the varnish by the varnish discharge section 46 to the semi-curing, resulting in a higher leveling effect. By making the distance between the semi-curing ultraviolet lamp 48 and the varnish discharge section 46 adjustable, the timing at which the varnish stops spreading can be adjusted, and the balance between leveling and shape stability can be adjusted. When the varnish layer is thick, the varnish spreads more due to the large volume of the varnish, so it is better to move the semi-curing ultraviolet lamp 48 closer to the varnish discharge section 46 and suppress the spread of the varnish early. When the varnish layer is thin, it is better to move the semi-curing ultraviolet lamp 48 away from the varnish discharge section 46 and allow sufficient time for leveling. In addition, when characters or the like are required to be relatively sharp, it is better to move the semi-curing ultraviolet lamp 48 closer to the varnish discharge section 46 and suppress the spread of the varnish early.

[0027] The foil stamping device 16 transports the web 52 in a roll-to-roll manner. The web 52 is a foil-holding film in which a foil (e.g., a metal foil) is held on the film. In the foil stamping device 16, the tackiness of the semi-cured varnish on the sheet is utilized to adhere the foil held by the web 52 to the varnish. Then, while the foil is held on the web 52 and adhered to the varnish on the sheet, the semi-cured varnish to which the foil is adhered is irradiated with ultraviolet light by the foil stamping ultraviolet lamp 66, and the varnish is fully cured. This results in a state in which the force of the fully cured varnish to adhere the foil is stronger than the force of the web 52 to hold the foil. In this state, the sheet and the web 52 are separated, and the foil held by the web 52 can be transferred to the portion of the sheet to which the varnish is applied.

[0028] The stacker 18 accumulates the sheets discharged from the foil stamping device 16 .

[0029] The control device 20 is, for example, 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 definition of a job 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 to perform foil stamping. The control device 20 controls the paper feeder 12, the varnish applicator 14, and the foil stamping device 16 based on the job definition.

[0030] In the process of irradiating ultraviolet rays onto the sheet onto which the varnish has been discharged by the varnish discharging unit 46, the control device 20 selects one of the first, second, and third modes, which differ in the combination of ultraviolet lamps used.

[0031] In the first mode, the sheet onto which varnish has been discharged by the varnish discharge unit 46 is irradiated with ultraviolet light by 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 by 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 by the final curing ultraviolet lamp 50, and the semi-curing ultraviolet lamp 48 and the foil stamping ultraviolet lamp 66 are turned off.

[0032] The first mode is selected when foil stamping is performed in the foil stamping device 16. That is, when foil stamping is performed on a sheet, the varnish is semi-cured by the semi-curing ultraviolet lamp 48. The output of the semi-curing ultraviolet lamp 48 is relatively stronger than that of the second mode. As shown in FIG. 3(a), the varnish layer has a tackiness on the surface layer, and its shape is stable. By utilizing this tackiness, the foil is adhered to the upper surface of the varnish layer in the foil stamping device 16. As shown in FIG. 3(a), since only the surface layer is uncured, even if the foil is adhered, the uncured portion is not crushed and does not spread in the sheet surface direction, and the shape of the varnish layer, especially the shape in the sheet surface direction, is stabilized. With the foil adhered to the varnish layer, the semi-cured varnish is fully cured by the foil stamping ultraviolet lamp 66, and 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.

[0033] The second mode is selected when foil stamping is not performed. In the second mode, the varnish on the sheet is semi-cured by the semi-curing ultraviolet lamp 48. Then, the varnish is fully cured by the full-curing ultraviolet lamp 50. The sheet passes through the foil stamping device 16, and foil stamping is not performed. The stacker 18 discharges the sheet on which a varnish layer is formed on the portion of the sheet to be varnished. The output of the semi-curing ultraviolet lamp 48 is relatively weaker than that of the first mode. As shown in FIG. 3(b), the varnish layer is in a state in which a relatively large amount of uncured portion 102a remains above the surface layer, while the portion adhering to the sheet S is mostly occupied by the cured portion 102b, and the adhesive portion is stabilized. Therefore, the varnish can be prevented from spreading, its shape is stabilized, and, in addition, while being transported to the full-curing ultraviolet lamp 50, the varnish in the upper uncured portion flows, exhibiting a leveling effect that flattens the upper surface, so that a varnish layer with a smooth upper surface is obtained.

[0034] In addition, in the second mode, the irradiation of ultraviolet light is shared between the semi-curing ultraviolet lamp 48 and the final curing ultraviolet lamp 50, so the heat irradiation of the sheet by ultraviolet light can be dispersed more than in the third mode, which uses a single light source for final curing. This makes it possible to prevent problems such as deformation such as curling of heat-sensitive sheets, discoloration of the underlying image due to heat, or melting of the toner.

[0035] The third mode is selected when foil stamping is not performed. In the third mode, the varnish on the sheet is not semi-cured by the semi-curing ultraviolet lamp 48, and only the full curing is performed by the full curing ultraviolet lamp 50. The sheet simply passes through the foil stamping device 16, and foil stamping is not performed. The sheet on which a varnish layer of a predetermined shape is formed at a predetermined position on the sheet is discharged to the stacker 18. Since semi-curing is not performed, the leveling effect during transport to the full curing ultraviolet lamp 50 is improved, resulting in a varnish layer with a smoother upper surface.

[0036] By being able to select between the first, second and third modes, an apparatus is obtained that can form a higher quality varnish layer even when simply applying varnish to a sheet.

[0037] 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.

[0038] The varnish layer obtained in the second mode is semi-cured, which has the effect of preventing the varnish layer from spreading in the direction of the sheet surface, and is therefore 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.

[0039] For example, if the thickness of the varnish layer is thick, the varnish spreads accordingly. Therefore, the second mode may be selected when the area includes an area where the thickness of the varnish layer is greater than or equal to a predetermined value. Also, if the area to which the varnish layer is to be applied 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 where the interval between adjacent varnish layers is small, the shape of the area to which the varnish is applied is likely to be distorted by the spread of the varnish layer. Therefore, the second mode may be selected when, for example, the area of ​​the object to which the varnish is to be applied on the sheet is less than or equal to a predetermined value, the minimum width of the varnish layer in the sheet surface direction is less than or equal to a predetermined value, or the interval between adjacent varnish layers is less than or equal to a predetermined value, etc., 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 one that is likely to spread, or a combination of both. And if these conditions for selecting the second mode are not met, the third mode, which provides excellent leveling properties, is selected.

[0040] The control device 20 may receive input from the user as to which of the first, second, and third modes to select, and select the mode input by the user. Alternatively, the first mode may be automatically selected only when the print job includes foil stamping, and when the print job does not include foil stamping, the control device 20 may receive input from the user as to which of the second and third modes to select. 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 to which the printing will spread in practice. The control device 20 may display the modes selected as selection candidates using the same algorithm as in the case of automatic selection as recommended modes on the user's input screen.

[0041] The basic configuration of the printing system 10 has been described above.

[0042] As a modification, the printing system 10 may include a printer, instead of the sheet feeder 12, that prints a base image and registration marks on the sheets, and feeds the sheets one by one from the printer.

[0043] In addition, the printing system 10 may be equipped with a post-processing device between the foil stamping device 16 and the stacker 18 that cuts and staples the sheets, a second varnishing unit to protect the foil surface, a paper inserter for surface protection purposes, a punching machine that punches out the sheets into a predetermined shape to create carton materials, etc., and a post-processing machine for surface protection of the paper inserts, etc.

[0044] Next, the configuration of the foil stamping device 16 will be described in detail. Figures 4 to 7 are views showing the foil stamping device 16. Figure 4 is a perspective view, Figures 5 and 6 are side views, and Figure 7 is a plan view. Figure 5 shows the nip rollers and the like in the raised position, and Figure 6 shows the nip rollers and the like in the lowered position.

[0045] 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 (not shown in Figures 4 and 7), a first nip roller 62, a second nip roller 64, a foil stamping ultraviolet lamp 66, a first sensor 68, a second sensor 70, and a sheet detection sensor 77.

[0046] The multiple transport rollers 54 transport the sheet toward the downstream side in the transport direction (left side in FIGS. 5 and 6) while nipping the sheet between the paper pressure roller 72, the nip rollers 62, 64, or the post-curing transport roller 73.

[0047] The paper pressing roller 72 is spherical as shown in FIG. 4, and a pair of paper pressing rollers 72 spaced apart in the width direction are arranged for one conveying roller 54. At least one of the pair of paper pressing rollers 72 is configured to be movable in the width direction according to the width of the sheet to be conveyed. With this configuration, only both ends in the width direction of the sheet to be conveyed are sandwiched between the paper pressing roller 72 and the conveying roller 54 and conveyed. In the sheet conveying direction, the sheet upstream of the foil transfer area (the area between the first nip roller 62 and the second nip roller 64) where the web 52 and the sheet contact each other holds semi-cured varnish on the upper surface. If the conveying member comes into contact with the semi-cured varnish, there is a risk of problems such as the varnish application state being disturbed or the conveying member being soiled. In response to this, the paper pressing roller 72 presses only both ends in the width direction of the sheet, thereby preventing the occurrence of such problems. In this embodiment, the sheet is abutted against the registration reference guide 32 to align the sheet in the width direction. Therefore, in the width direction, the sheet is transported based on the side where the registration reference guide 32 is provided. Of the paper pressure rollers 72, the paper pressure roller 72 that is on the same side as the registration reference guide 32 in the width direction does not move in the width direction, so it may be formed in a roller shape rather than a spherical shape to improve the transportability of the sheet.

[0048] On the other hand, the post-curing conveying roller 73 is a member in which multiple roller portions 73a are arranged on one rotating shaft extending in the width direction, as shown in Fig. 4. The multiple roller portions 73a are configured not to move in the width direction (axial direction). The varnish on the upper surface of the sheet downstream of the foil transfer area is fully cured by the foil stamping ultraviolet lamps 66, so that the sheet can be conveyed without the above-mentioned inconvenience occurring even if the roller portion 73a of the post-curing conveying roller 73 comes into contact with the sheet.

[0049] The unwinding shaft 56 supports an unused roll of web (hereinafter referred to as unwinding roll 74). The unwinding shaft 56 is formed of a friction shaft. A plurality of guide rollers 60, a first nip roller 62, and a second nip roller 64 define the path of the web. The second nip roller 64 is located downstream of the first nip roller 62 in the conveying direction.

[0050] Between the first nip roller 62 and the second nip roller 64, the web 52 and the sheet come into contact. At this time, the foil is transferred from the web 52 to the semi-cured varnish on the sheet. During the transfer, the varnish on the sheet and the web 52 are temporarily adhered to each other, so that the web 52 is fed at the same speed as the sheet. The second nip roller 64 may be driven to rotate and the web 52 may be fed at the same speed as the sheet. Here, if a drive source for driving the nip rollers 62 and 64 is provided and a speed difference occurs between the surface movement speed between the nip rollers 62 and 64, which holds the foil, and the sheet, which is the sheet to which the foil is transferred, and which is the sheet to which the foil is transferred, and which is the sheet to which the foil is transferred, and which is the sheet to which the foil is transferred, is contacted with the conveying roller 54, this causes wrinkles in the foil. In contrast, in this embodiment, a drive source for driving the nip rollers 62 and 64 is not provided, and the nip rollers 62 and 64 are configured to rotate in response to the movement of the web 52, thereby suppressing wrinkles in the foil.

[0051] The winding shaft 58 winds up the used web 52, i.e., the film and the foil remaining on the film, into a roll. Hereinafter, the roll-shaped web 52 wound by the winding shaft 58 is referred to as a winding roll 76. The winding shaft 58 is composed of a friction shaft. The friction shaft has a structure that allows the rotation speed to be varied depending on the position in the axial direction (i.e., the width direction). The winding shaft 58 is driven to rotate by a drive source (not shown).

[0052] At least one of the guide rollers 60 is fitted with an encoder (not shown) for detecting the number of rotations. The guide roller 60 fitted with the encoder is preferably designed to reduce slippage with the web 52, for example by using a material with a high coefficient of friction on the surface. In the foil transfer area, the foil on the outer peripheral surface of the web 52 comes into contact with the surface of the sheet or the conveying roller 54, and moves downstream in the conveying direction of the sheet by rotating with these surfaces. The control device 20 calculates the moving speed of the web 52 based on the detection result by the encoder, and controls the number of rotations of the unwinding shaft 56 so that the unwinding speed of the web 52 from the unwinding roll 74 is slower than the calculated moving speed of the web 52. At this time, the moving speed of the web 52 is faster than the unwinding speed caused by the rotation of the unwinding shaft 56, but the circumferential surface of the unwinding shaft 56, which is a friction shaft, rotates relative to the drive input shaft, and the circumferential surface rotates faster than the drive input shaft, so that the web 52 can be unwound so as to be at the same speed as the moving speed of the sheet in the foil transfer area while keeping the web 52 in a taut state.

[0053] In addition, the control device 20 controls the rotation speed of the winding shaft 58 so that the winding speed of the web 52 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 by the rotation of the unwinding shaft 56, but the circumferential surface of the winding shaft 58 made of a friction shaft rotates relative to the drive input shaft, and the drive input shaft rotates idly relative to the circumferential surface, so that the web 52 can be wound up at the same speed as the moving speed of the sheet in the foil transfer area while keeping the web 52 in a taut state.

[0054] A UV foil stamping lamp 66 is mounted above the web path between the first nip roller 62 and the second nip roller 64 .

[0055] The first nip roller 62, the second nip roller 64, the foil stamping ultraviolet lamp 66, and some of the guide rollers 60 are each configured to be movable up and down between the raised position in Fig. 5 and the lowered position in Fig. 6. The raised position is a position where the web 52 cannot come into contact with the sheet being transported. The lowered position is a position where the web 52 can come into contact with a sheet being transported that is adjacent to and parallel to the web 52. The control device 20 positions the nip rollers etc. in the raised position when the sheet is not to be foil stamped (i.e., in the second or third mode in which varnish is only applied), and positions the nip rollers etc. in the lowered position when the sheet is to be foil stamped (in the first mode).

[0056] The sheet detection sensor 77 is a sensor that detects the timing of transfer in the foil transfer area. The sheet detection sensor 77 detects the presence or absence of a sheet at the detection position, and can detect the timing of the leading edge and trailing edge of the sheet based on the detection result. When the nip rollers, etc. are in the raised position, the nip rollers, etc. are moved toward the lowered position at a predetermined timing after it is detected that the leading edge of the sheet to be stamped has passed the detection position of the sheet detection sensor 77. In addition, after it is detected that the trailing edge of the sheet to be stamped has passed the detection position of the sheet detection sensor 77, the nip rollers, etc. are moved from the lowered position toward the raised position at a predetermined timing as necessary.

[0057] In this embodiment, the first nip roller 62, one guide roller 60 adjacent to the first nip roller 62 on the upstream side of the transport path of the web 52, and one guide roller 60 adjacent to the second nip roller 64 on the downstream side of the transport path of the web 52 move between an elevated position and a lowered position. When these members move from the elevated position to the lowered position, the movement path of the web 52 from the unwinding roll 74 to the winding roll 76 becomes longer. At this time, the circumferential surface rotates faster with respect to the drive input shaft of the unwinding shaft 56, and the web 52 is unwound by the amount of the movement path that has become longer. On the other hand, when the above-mentioned members move from the lowered position to the elevated position, the movement path of the web 52 from the unwinding roll 74 to the winding roll 76 becomes shorter. At this time, the circumferential surface rotates faster without the drive input shaft of the winding shaft 58 rotating idly, and the web 52 is wound up by the amount of the movement path that has become shorter, thereby preventing the web 52 from bending.

[0058] The first sensor 68 is a distance measuring sensor and is provided radially outside the unwinding roll 74. The first sensor 68 is preferably provided between the unwinding roll 74 and the take-up roll 76 in the transport direction as shown in the figure. In this case, the foil stamping device 16 can be made compact in the transport direction.

[0059] The first sensor 68 is preferably a laser type distance measuring sensor, but is not limited to this and any known distance measuring sensor such as an infrared sensor, a capacitance type, an ultrasonic type, a high frequency laser type, or an eddy current type can be used.

[0060] The first sensor 68 scans in the width direction. In particular, the first sensor 68 scans the entire possible range of the web 52 (unwind roll 74). The possible range is the range in the width direction in which the web 52 can be provided. In this example, the first sensor 68 scans in the width direction by reciprocating in the width direction. Note that the first sensor 68 may also scan in the width direction by rotating around a predetermined axis. It is sufficient that the first sensor 68 scans in the width direction at least when performing either the determination or the remaining amount estimation described below.

[0061] The second sensor 70 is provided so as to be able to detect the web 52 being fed out, in other words, the web 52 on the transport path, in other words, the web 52 that has been fed out from the unwind roll 74 and has not yet been taken up by the take-up roll 76. The second sensor 70 may be a reflective sensor, a distance measuring sensor, or any other sensor as long as it can detect the web 52 being fed out. By detecting the web 52 being fed out, it becomes possible to detect whether the web 52 is tensioned.

[0062] Here, when the web 52 breaks, the web 52 that is not wound around the winding roll 76 may remain in the transport path. However, in the portion of the transport path of the web 52 where the web 52 moves vertically upward, the web 52 that is not wound around the winding roll 76 when the web 52 breaks loses tension and falls, so that the web 52 is unlikely to remain. Therefore, the second sensor 70 is preferably provided so as to be able to detect the web 52 on the transport path moving vertically upward, as shown in Figs. 5 and 6. In this case, it is possible to prevent the second sensor 70 from detecting the web 52 even when the web 52 is broken and is not stretched. As for the arrangement of the second sensor 70 in the transport direction, it is preferable to provide the second sensor 70 between the unwinding roll 74 and the winding roll 76, as shown in Figs. 5 and 6. This allows the foil stamping device 16 to be made compact in the transport direction.

[0063] The second sensor 70 is an ultrasonic sensor. The second sensor 70 must be able to detect the web 52 that no longer holds the foil after passing through the foil transfer area. The web 52, which has had the foil transferred onto the sheet and no longer holds the foil, is often transparent, and may be difficult to detect with an optical sensor. For this reason, an ultrasonic sensor or a capacitive sensor that can detect based on the physical presence of the web 52 regardless of whether it transmits light or not is preferable. On the other hand, an optical sensor may be used by detecting the foil remaining near both ends in the width direction or by using the web 52 that is not transparent even after the foil transfer.

[0064] The second sensor 70 scans in the width direction. In particular, the second sensor 70 scans the entire range in which the web 52 can exist. In this example, the second sensor 70 scans in the width direction by reciprocating in the width direction. Note that the second sensor 70 may also scan in the width direction by rotating around a predetermined axis. As with the first sensor 68, the second sensor 70 only needs to scan in the width direction when performing at least one of the determination and remaining amount estimation described below.

[0065] FIG. 8 is a plan view showing the foil stamping device 16 and the sheet S transported toward the foil stamping device 16. When the user performs foil stamping on the sheet S, the web 52 is provided so that the processing range Rp falls within the widthwise existence range Rw of the web 52 when viewed in the transport direction α (i.e., when viewed from the upstream side of the transport direction α to the downstream side of the transport direction α along the transport direction α). That is, when defining a coordinate axis in the width direction, the web 52 is provided so that the coordinate range of the processing range Rp falls within the coordinate range of the existence range Rw of the web 52. In other words, the web 52 is provided so that the entire coordinate range of the processing range Rp overlaps the coordinate range of the existence range Rw of the web 52. If at least a part of the coordinate range of the processing range Rp does not overlap the coordinate range of the existence range Rw of the web 52, the foil is not transferred to the varnish in the processing range corresponding to the at least part of the coordinate range.

[0066] Here, the processing range Rp is a continuous range in the width direction of the sheet S where the foil stamping process, that is, the process of transferring foil from the web 52 to the sheet S, is performed. The processing range Rc is a range in the conveying direction of the sheet S where the foil stamping process is performed. When there are multiple continuous ranges in the width direction on the sheet S, the processing range Rp indicates each individual range. When there are multiple continuous ranges in the conveying direction on the sheet S where the foil transfer process is performed, the processing range Rc is a range from the leading edge of the processing range on the downstream side of the conveying direction to the trailing edge on the upstream side of the conveying direction. The leading edge non-processed portion Rcf indicates a range from the leading edge of the sheet S to the leading edge of the processing range Rc. The trailing edge non-processed portion Rcr indicates a range from the trailing edge of the processing range Rc to the trailing edge of the sheet S. In this embodiment, the control device 20 specifies the processing ranges Rp and Rc based on the varnish data. That is, in this embodiment, the control device 20 specifies the processing ranges Rp and Rc assuming that the foil is transferred to the area where the varnish is applied. The control device 20 may specify, as the processing ranges Rp, Rc, a widthwise range for foil stamping that is specified by data other than the varnish data.

[0067] When there are a plurality (N) of processing ranges Rp_i (i=1, ...N), if the interval Dk between adjacent processing ranges Rp_k (k=1, ...N-1) and processing range Rp_k+1 is equal to or less than a predetermined threshold DTH, the control device 20 collectively identifies the processing range Rp_k, the processing range Rp_k+1, and the range Rb_k therebetween as one processing range Rp. In the example of Fig. 8, the control device 20 identifies two processing ranges Rp.

[0068] Further, the existence range Rw of the web 52 in the width direction is the actual existence range within the possible existence range Rmax of the web 52 in the width direction. The existence range Rw can be specified based on the detection result by the first sensor 68 or the second sensor .

[0069] 9 is a diagram showing an example of the detection result by the first sensor 68. As described above, the first sensor 68 is a distance measuring sensor. Therefore, the detection result by the first sensor 68 indicates the distance L from the first sensor 68 to the outer circumferential surface of the unwinding shaft 56 or the outer circumferential surface of the unwinding roll 74 at each position in the width direction. The detection result can also be said to be data indicating the outer diameter of the unwinding roll 74. The control device 20 can identify a continuous range in which the distance L indicated by the detection result of the first sensor 68 is shorter than the distance L0 to the winding shaft 58 as the existence range Rw of the web 52 in the width direction.

[0070] 10 is a diagram showing an example of the detection result by the second sensor 70. In this example, the second sensor 70 is a reflective sensor. The detection result by the second sensor 70 indicates the amount of reflected light received at each position in the width direction. The amount of reflected light received is high at a position where the web 52 is present. The control device 20 can identify a continuous range in which the amount of received light indicated by the detection result of the second sensor 70 is higher than a predetermined threshold as the presence range Rw of the web 52 in the width direction.

[0071] Next, the control of the foil stamping device 16 by the control device 20 will be described in detail.

[0072] (Determining installation of unwind roll) The control device 20 determines whether or not the unwinding roll 74 is attached to the unwinding shaft 56. The control device 20 performs this determination when an operation to start a job is input, when a button for tensioning the web 52 is operated after the web 52 is laid between the unwinding shaft 56 and the winding shaft 58, when the varnish data is read, or when a button for executing the determination is operated. The same applies to the tension determination and the presence range determination of the web 52, which will be described later.

[0073] Specifically, the control device 20 determines that the unwinding rolls 74 are attached (i.e., present) in a continuous range where the distance L indicated by the detection result of the first sensor 68 is shorter than the distance L0 to the winding shaft 58. In the example of FIG. 8, the control device 20 determines that two unwinding rolls 74 are attached to the unwinding shaft 56. For example, the control device 20 may warn the user of the fact by display or sound when no unwinding rolls 74 are attached. Also, for example, the control device 20 may determine the processing range based on the varnish data, and when the number of the determined unwinding rolls 74 does not match the number of the determined processing range, may warn the user of the fact by display or sound. By issuing a warning when the number of unwinding rolls 74 is smaller than the number of processing ranges, it is possible to prevent forgetting to attach the unwinding rolls 74. Also, by issuing a warning when the number of unwinding rolls 74 is greater than the number of processing ranges, it is possible to prevent forgetting to remove the unwinding rolls 74 that are not used in the next job.

[0074] (Web 52 tension determination) The control device 20 determines whether the unwinding roll 74 attached to the unwinding shaft 56 is stretched from the unwinding shaft 56 to the winding shaft 58. Specifically, the control device 20 determines whether the presence range Rw of the web 52 in the width direction (unwinding roll 74) specified by the detection result of the first sensor 68 and the presence range of the web 52 specified by the detection result of the second sensor 70 match when viewed in the conveying direction. That is, when defining a coordinate axis in the width direction, the control device 20 determines whether the coordinate range of the presence range Rw of the web 52 (unwinding roll 74) based on the detection result of the first sensor 68 matches the coordinate range of the presence range Rw of the web 52 based on the detection result of the second sensor 70. If the two do not match, it is considered that the unwinding roll 74 is attached to the unwinding shaft 56 but the web 52 is not stretched, specifically, that the web 52 has been forgotten to be stretched, or that the web 52 has broken. In this case, the control device 20 warns the user of this by display or sound. This makes it possible to prevent the web 52 from being left untaut. Also, when the web 52 breaks, it is possible to detect an abnormality in which the ranges Rw detected by the first sensor 68 and the second sensor 70 do not match, and it is possible to prevent a job from being executed in a state in which the web 52 breaks. Furthermore, when the web 52 located in the range Rw that is not required for the next job is removed from only one of the unwinding shaft 56 and the winding shaft 58 while forgetting to remove the other, it is possible to prevent a job from being executed in a state in which the web 52 has been left untaped by detecting the abnormality.

[0075] (Web 52 Extent Determination) The control device 20 judges whether the processing range Rp is contained within the existence range Rw when viewed in the conveying direction. That is, when the coordinate axis is defined in the width direction, the control device 20 judges whether the coordinate range of the processing range Rp is contained within the coordinate range of the existence range Rw. In other words, the control device 20 judges whether the entire coordinate range of the processing range Rp overlaps with the coordinate range of the existence range Rw. The existence range Rw may be an existence range specified by the detection result of the first sensor 68 or an existence range specified by the detection result of the second sensor 70. If at least a part of the coordinate range of the processing range Rp does not overlap with the coordinate range of the existence range Rw, the foil is not transferred to the varnish of the processing range corresponding to the at least part. In this case, the control device 20 warns the user of this fact by display or sound. Note that the control device 20 makes this judgment when a job start operation is input, and if the processing range Rp is not contained within the existence range Rw, the control device 20 does not start the job and warns the user. This makes it possible to prevent the processing range Rp from extending beyond the width direction of the existence range Rw when viewed in the transport direction, and allows the foil to be transferred to the entire varnish in the processing range Rp.

[0076] The control device 20 also specifies the width of the portion of the existence range Rw that does not overlap with the processing range Rp when viewed in the conveying direction. That is, when defining coordinate axes in the width direction, the control device 20 specifies the width of the coordinate range of the existence range Rw that does not overlap with the coordinate range of the processing range Rp. If the width is equal to or greater than a predetermined threshold width, the control device 20 determines that there is a lot of waste in the width direction of the web 52 (foil) and warns the user to that effect by display or sound. This makes it possible to reduce waste of foil.

[0077] (Estimated remaining amount of Web 52) The control device 20 estimates the remaining amount of the web 52 based on the detection result by the first sensor 68. By estimating the remaining amount of the web 52, the user can take appropriate measures to prevent the foil from being transferred to the sheet. The control device 20 estimates the remaining amount, for example, when a job definition is input, when an operation to start the job is input, or at a predetermined timing (for example, at a predetermined cycle) during the execution of the job.

[0078] For example, the control device 20 may estimate the number of processable sheets under the job conditions (sheet size) set at that time as the remaining amount of the unwinding roll 74. The control device 20 may estimate the number of processable sheets based on a calculation formula with parameters of the diameter of the unwinding roll 74, the diameter of the unwinding shaft 56, the thickness of the web 52, and the length of the web 52 used for foil stamping of one sheet. The length of the web 52 used for foil stamping of one sheet is, for example, a value obtained by adding a predetermined margin length β to the processing range Rc, but may also be the length of one sheet. If the estimated number of processable sheets is less than the number of prints in the job, that is, if the remaining amount of the web 52 is insufficient, the control device 20 warns the user of this by display or sound. If the control device 20 determines that the remaining amount of the web 52 is insufficient in the remaining amount determination when the start operation of the job is input, the control device 20 may warn the user of the insufficient remaining amount without starting the job, may start the job while warning the user of the insufficient remaining amount, or may warn the user of the insufficient remaining amount and allow the user to select whether to start the job as is. Furthermore, when the control device 20 determines that the remaining amount is insufficient, it may notify the user by display or sound of the number of sheets that can be processed by the remaining web 52. In this case, the number of sheets notified to the user may be the number of processable sheets estimated as described above, or may be the number obtained by multiplying the estimated number of processable sheets by a predetermined safety factor (0.8).

[0079] The diameter of the unwinding roll 74 is determined from the difference between the distance LC from the first sensor 68 to the central axis of the winding shaft 58 and the distance L indicated by the detection result of the first sensor. The distance LC may be stored in advance in the control device 20. The diameter of the unwinding shaft 56, the thickness of the web 52, and the length of the web 52 used for foil stamping of one sheet may be input by the user at a predetermined timing.

[0080] For example, the control device 20 may specify (estimate) the radial thickness of the unwinding roll 74 as the remaining amount of the unwinding roll 74. The control device 20 may specify the radial thickness of the unwinding roll 74 from the difference between the distance L0 from the first sensor 68 to the unwinding shaft 56 and the distance L indicated by the detection result of the first sensor 68. If the specified radial thickness is equal to or less than a predetermined thickness threshold, that is, if the remaining amount of the web 52 is low, the control device 20 warns the user of this by display or sound. If the control device 20 determines that the remaining amount of the web 52 is low in the remaining amount determination during execution of a job, the control device 20 may warn the user that the remaining amount is low while canceling or stopping the job, may warn the user that the remaining amount is low without canceling or stopping the job, or may warn the user that the remaining amount is low while warning the user that the remaining amount is low.

[0081] The thickness threshold may be input by the user or may be stored in the control device 20 in advance.

[0082] Furthermore, if the diameter r of the unwinding shaft 56 is different, the length of the remaining web 52 will be different even if the radial thickness of the unwinding roll 74 is the same. Therefore, the control device 20 may correct the thickness threshold value according to the diameter of the unwinding shaft 56. For example, the control device 20 may increase the thickness threshold value as the diameter of the unwinding shaft 56 increases, and decrease the thickness threshold value as the diameter decreases.

[0083] 11(a) and (b) are diagrams showing an example of a scene determined by the control device 20. In Fig. 11(a) and (b), an unwinding roll 74 is provided corresponding to each processing range Rp, the web 52 is stretched around each unwinding roll 74, and each processing range Rp falls within the existence range Rw of the corresponding web 52.

[0084] 12(a) to (d) are diagrams showing another example of a scene of judgment by the control device 20. In Fig. 12(a), the unwinding roll 74 corresponding to one of the two processing ranges Rp is not provided. In this case, the control device 20 warns the user as a result of at least one of the judgments of the attachment of the unwinding roll and the judgment of the presence range of the web 52.

[0085] 12B, when viewed in the conveying direction α, one of the two processing ranges Rp does not fall within the corresponding existence range Rw. In this case, the control device 20 warns the user as a result of the existence range determination of the web 52.

[0086] 12C, the web 52 of one of the two unwinding rolls 74 is broken and not tensioned. In this case, the control device 20 warns the user as a result of determining that the web 52 is tensioned.

[0087] In Fig. 12(d), the width W of the portion of the existence range Rw that does not overlap with the processing range Rp when viewed in the transport direction α is equal to or greater than the threshold width WTH. In Fig. 12(e), when viewed in the transport direction α, there is no processing range Rp that corresponds to one of the two existence ranges Rw. In other words, when viewed in the transport direction α, one of the two existence ranges Rw does not overlap with the processing range Rp at all. In these cases, the control device 20 warns the user based on the result of the existence range determination of the web 52.

[0088] (Foiling operation) 13(a)-(d) and 14(a)-(d) are diagrams showing the time series of the foil stamping operation when performing foil stamping (first mode). FIG. 13(a) shows the stage where the leading edge of the first sheet S1 has reached the sheet detection sensor 77. At this stage, the sheets S1 have already been fed one by one from the sheet feeder 12, varnished in the varnish applicator, and semi-cured by the semi-curing ultraviolet lamp 48. The sheet S1 has leading edge non-processed areas Rcf, processing ranges Rc, and trailing edge non-processed areas Rcr, in that order from the leading edge side. The leading edge non-processed areas Rcf and the trailing edge non-processed areas Rcr are not varnished. The processing range Rc is a range where a varnished area exists. When there are multiple ranges on the sheet S where the varnished areas are continuous in the conveying direction, the processing range Rc is a range from the leading edge of the processing range on the downstream side of the conveying direction to the trailing edge on the upstream side of the conveying direction. The first nip roller 62 and the second nip roller 64 are in the raised position. The foil transfer area F is where the web 52 holding the foil comes into contact with the sheet S and the foil is transferred to the sheet. The sheet S1 is moved in the direction of the arrow by the transport roller 54 (see Figs. 5 and 6) and the paper pressure roller 72. The main curing ultraviolet lamp 66 is turned off.

[0089] FIG. 13(b) shows that the first nip roller 62 and the second nip roller 64 are lowered to the lowered position by a drive mechanism (not shown) just before the leading edge of the processing area Rc enters the foil transfer area F as the sheet S1 moves. The timing of the descent is the point at which a pulse is obtained by an encoder interposed in the drive mechanism of the conveying roller 54, and a predetermined number of pulses P1 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S1. The predetermined number of pulses P1 is determined based on the length of the leading edge non-processed portion Rcf in the conveying direction obtained from the varnish data. When the sheet S1 moves further, it adheres to the web 52 due to the tackiness of the semi-cured varnish, and the web 52 also starts to move along with the sheet S1 moving by the conveying roller 54.

[0090] In FIG. 13(c), the leading edge of the processing region Rc reaches the point immediately before it enters the irradiation range U of the main curing ultraviolet lamp 66. At this timing, the main curing ultraviolet lamp 66 turns on. The timing of lighting is the point where a predetermined number of pulses P2 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S1. This predetermined number of pulses P2 is determined in advance based on the length of the leading edge non-processed portion Rcf obtained from the varnish data in the transport direction so that the main curing ultraviolet lamp 66 (ultraviolet ray irradiation section) is turned on at a timing immediately before the processing region Rc (varnish applied portion) on the sheet arrives in the irradiation range F of the main curing ultraviolet lamp 66 (ultraviolet ray irradiation section).

[0091] 13(d), the sheet S1 overlaps the web 52 and moves further while the semi-cured varnish is irradiated by the UV lamp 66 for full curing. This irradiation fully cures the varnish. The fully cured varnish strongly bonds the foil of the web 52 and the sheet S1. The web 52 has already separated near the tip of the processing region Rc, but the foil remains in the area of ​​the sheet S1 where the varnish was applied, bonded by the fully cured varnish.

[0092] 14(a) shows the state immediately after the rear end of the processing region Rc leaves the irradiation range U of the main curing ultraviolet lamp 66. At this timing, the main curing ultraviolet lamp 66 is turned off. The timing of turning off the lamp is the point where a predetermined number of pulses P3 is counted after the sheet detection sensor 77 detects the leading edge of the sheet S1. This predetermined number of pulses P3 is determined in advance based on the leading edge non-processed portion Rcf obtained from the varnish data and the length of the processing region Rc in the conveying direction, so that the main curing ultraviolet lamp 66 (ultraviolet ray irradiation section) is turned off immediately after the processing region Rc (varnish-coated portion) on the sheet passes through the irradiation range F of the main curing ultraviolet lamp 66 (ultraviolet ray irradiation section).

[0093] Next, as shown in FIG. 14(b), the sheet S1 moves further while overlapping with the web 52.

[0094] FIG. 14(c) shows that the first nip roller 62 and the second nip roller 64 are raised to the raised position by a drive mechanism (not shown) immediately after the rear end of the processing area Rc leaves the foil transfer area F. The timing of the rise is the point where the sheet detection sensor 77 detects the leading edge of the sheet S1 and counts a predetermined number of pulses P4. The predetermined number of pulses P4 is determined based on the leading edge non-processed portion Rcf obtained from the varnish data and the length of the processing area Rc in the conveying direction. Since the sheet S1 and the web 52 are separated, the movement of the web 52, which is caused by the movement of the sheet S1, stops. Even if the first nip roller 62 and the second nip roller 64 are raised, the web 52 is taken up by the take-up roll 76 by the driving rotation of the take-up shaft 58, so that the web 52 does not sag.

[0095] The sheet S1, with the foil adhered to the varnished portion in this manner, is discharged into stacker 18 (see FIGS. 1 and 2), and the foil stamping process for sheet S1 is completed.

[0096] Next, as shown in Fig. 14(d), the leading edge of the next sheet S2 is detected by the sheet detection sensor 77. Thereafter, the same operations as those shown in Figs. 13(b) to (d) and Figs. 14(a) to (d) are performed for the sheet S2. This operation is repeated until the processing of the number of sheets determined in the job data is completed. That is, for each sheet, the main curing ultraviolet lamp 66 is turned on just before the leading edge of the processing area Rc enters the irradiation range U of the main curing ultraviolet lamp 66, and the main curing ultraviolet lamp 66 is turned off just before the rear end of the processing area Rc leaves the irradiation range U of the main curing ultraviolet lamp 66.

[0097] The ultraviolet light from the final curing ultraviolet lamp 66 is intended to completely cure the semi-cured varnish between the foil of the web 52 and the sheet S in the treatment range Rc, thereby ensuring that the foil is bonded to the sheet S.

[0098] However, if ultraviolet light is irradiated for a predetermined period of time or longer while the web 52 is stationary, the heat may cause deformation or melting of the web 52. To avoid this, it is necessary to turn off the main curing ultraviolet lamp 66 while the web 52 is stationary or there is a possibility that the web 52 may be stationary.

[0099] The web 52 moves when the first nip roller 62 and the second nip roller 64 are in the lowered position and the web 52 and the sheet S are sandwiched between the conveying roller 54 in an overlapping state.

[0100] Even if the first nip roller 62 and the second nip roller 64 are in the lowered position, if the sheet S is not in contact with the web 52, there is a gap between the web 52 and the conveying roller 54 that is large enough for the sheet S to enter, so the web 52 may not move.

[0101] Therefore, it is desirable that the main curing ultraviolet lamp 66 be turned on after the first nip roller 62 and the second nip roller 64 are in the lowered position and the sheet S comes into contact with the web 52, and before the processing range Rc enters the irradiation area U. Also, it is desirable that the main curing ultraviolet lamp 66 be turned off after the processing range Rc leaves the irradiation area U, and before the sheet S and the web 52 are separated from each other, with the first nip roller 62 and the second nip roller 64 in the raised position.

[0102] In this embodiment, since the upstream end of the irradiation range U is provided downstream of the upstream end of the foil transfer area F (between the first nip roller 62 and the second nip roller 64), the main curing ultraviolet lamp 66 can be turned on between the contact between the moving sheet S and the web 52 and the time when the processing area Rc enters the irradiation area U. Also, since the downstream end of the irradiation range U is provided upstream of the downstream end of the foil transfer area F (between the first nip roller 62 and the second nip roller 64), the main curing ultraviolet lamp 66 can be turned off between the exit of the processing area Rc from the irradiation area U and the time when the moving sheet S and the web 52 are separated.

[0103] In this embodiment, the web 52 moves by contacting the moving sheet S, but if there is a separate drive for moving the web 52, the main curing ultraviolet lamp 66 may be turned off while the web 52 is stopped in accordance with the on / off timing of the drive.

[0104] In addition, in the present embodiment, an example in which one processing range Rc is formed on the sheet S has been described, but if the areas to be varnished are far apart from each other on the leading end side and the trailing end side of the sheet S, each may be treated as a separate processing range Rc, and multiple processing ranges Rc may be set on one sheet S, and the main curing ultraviolet lamp 66 may be controlled to be turned on and off corresponding to each processing range Rc. Specifically, the control may be performed individually for each of the multiple processing ranges Rc, such that the lamp is turned on just before the leading end of the processing range Rc reaches the irradiation range U, and the lamp is turned off just after the trailing end of the processing range Rc leaves the irradiation range U. By doing so, the time for irradiating the sheet S with ultraviolet light can be shortened, and defects such as deformation of the sheet S due to the heat of the ultraviolet light can be suppressed.

[0105] Furthermore, when the processing range Rc on the leading edge side and the processing range Rc on the trailing edge side are adjacent in the transport direction, and the distance between the rear end of the processing range Rc on the leading edge side and the leading edge of the processing range Rc on the trailing edge side is longer than the length of the foil transfer area F in the transport direction, the first nip roller 62 and the second nip roller 64 may be in the raised position from immediately after the rear end of the processing range Rc on the leading edge side leaves the foil transfer area F to just before the leading edge of the processing range Rc on the trailing edge side enters the foil transfer area F. Since the web 52 is stopped and not fed while the first nip roller 62 and the second nip roller 64 are in the raised position, it is preferable to turn off the main curing ultraviolet lamp 66 after the rear end of the processing range Rc on the front end side leaves the irradiation range U and before the first nip roller 62 and the second nip roller 64 rise, and then turn it on again after the first nip roller 62 and the second nip roller 64 descend and before the front end of the processing range Rc on the rear end side enters the irradiation range U. By doing so, the length of the web 52 to be fed can be reduced, which leads to saving of foil.

[0106] Furthermore, when 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.

[0107] Furthermore, since the web 52 can tolerate the ultraviolet light from the main curing ultraviolet lamp 66 being irradiated with the ultraviolet light during stoppage for a very short period of time, the main curing ultraviolet lamp 66 may be turned on or off at a timing such that the irradiation time during stoppage does not exceed a predetermined time.

[0108] 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 processing step, and that such modifications are also within the scope of the present invention. Such modifications will be described below.

[0109] (Variation 1) In the embodiment, the first sensor 68 and the second sensor 70 scan the entire possible range of the web 52, but at least one of the first sensor 68 and the second sensor 70 may scan only a part of the possible range. For example, at least one of the first sensor 68 and the second sensor 70 may scan only a coordinate range based on the processing range Rp, specifically, only the coordinate range of the processing range Rp, or only a coordinate range including the processing range and the margins on both sides of the processing range.

[0110] (Variation 2) The sensors 68, 70 do not need to scan in the width direction every time. For example, while a job is being executed, the width-wise existence range Rw of the web 52 has been determined by the scan up to that point. Therefore, while a job is being executed, the sensors 68, 70 may be fixed at a position overlapping the existence range Rw when viewed in the conveyance direction. If multiple unwinding rolls 74 are provided, that is, if there are multiple existence ranges Rw, the position of the sensors 68, 70 may be moved to a different existence range Rw at a predetermined timing, for example, each time one sheet is foil stamped.

[0111] (Variation 3) In the embodiment, the first sensor 68 and the second sensor 70 are described as scanning in the width direction, but this is not limited to this, and at least one of the first sensor 68 and the second sensor 70 may be a sensor array (such as a line sensor) in which multiple detection elements are continuously arranged in the width direction.

[0112] (Variation 4) In the embodiment, the foil stamping device 16 is described as having two sensors 68, 70, but the foil stamping device 16 may have only one sensor for detecting the presence or absence of the web 52.

[0113] For example, the foil stamping device 16 may include only the first sensor 68. In this case, the user may determine whether the web 52 is stretched or not. Although this is a more cumbersome task than the automatic determination in the embodiment, the user can easily determine whether the web 52 is stretched or not because it is clear at a glance whether the web 52 is stretched or not.

[0114] Also, for example, the foil stamping device 16 may include only the second sensor 70. In this case, the user may check the unwinding roll 74 as needed and visually check the remaining amount of the unwinding roll 74 (i.e., the web 52). Alternatively, the user may check the processed sheet as needed and quickly notice when the remaining amount of the web 52 runs out.

[0115] Also, for example, the foil stamping device 16 may include a third sensor capable of detecting the unwinding roll 74, instead of the first sensor 68 and the second sensor 70. The control device may specify the range in which the web 52 exists based on the detection result of the third sensor. In this case, the user may visually check whether the web 52 is stretched and whether the remaining amount of the web 52 is sufficient.

[0116] (Variation 5) In the embodiment, as in the example of Fig. 12(e), if there is an unwinding roll 74 whose existence range Rw does not overlap at all with the processing range Rp when viewed in the conveying direction, a warning is given to the user. In this modified example, if the unwinding roll 74 is simply attached to the unwinding shaft 56 and is not tensioned, there is no need to warn the user. In this case, there is no need to perform a tension determination of the web 52.

[0117] (Variation 6) A distance measuring sensor may be used as the second sensor 70, and the orientation of the second sensor 70 may be changed to detect the diameter of the take-up roll 76. The control device 20 may correct the driving rotation speed of the unwinding shaft 56 based on the detected value. Specifically, the rotation speed may be slower as the diameter increases.

[0118] (Variation 7) In addition to the first sensor 68 and the second sensor 70, a fourth sensor capable of estimating the outer diameter by measuring the distance from the outer circumferential surface of the winding roll 76 may be provided. When the estimated outer diameter exceeds a predetermined threshold (specifically, when the distance from the outer circumferential surface of the winding roll 76 falls below a predetermined threshold), the control device may issue a warning that the winding roll 76 is full. Since the web 52 may no longer hold the foil even on the winding roll 76, it is preferable that the fourth sensor is an ultrasonic or capacitive distance measuring sensor. On the other hand, an optical sensor may be used by detecting a portion where the foil always remains or by using a web 52 that is not transparent even after foil transfer. The fourth sensor may also be capable of scanning in the width direction, and when multiple webs 52 are hung on the winding shaft 58, the outer diameter of each web 52 may be estimated. Instead of this fourth sensor, an optical sensor may be provided with an optical axis arranged approximately parallel to the width direction so that the optical axis is blocked when the diameter of the wound web 52 becomes equal to or larger than a predetermined value.

[0119] (Variation 8) In the embodiment, a processing apparatus equipped with the web detection device according to the present invention and performing a predetermined process on a sheet from a web, which is a foil-holding film with foil laminated thereon, has been described, which performs a process called cold foiling, in which the foil held on the web 52 is transferred to the sheet by the adhesive force of the varnish. The predetermined process performed by the processing apparatus is not limited to cold foiling. For example, a process called hot foiling, in which the foil held on the web is transferred to the sheet by heat and pressure, may also be used. In addition, the processing is not limited to foil transfer, and may also be a process of transferring ink from a web-shaped ink ribbon to a sheet.

[0120] Furthermore, the web detection device according to the present invention is not limited to a device that performs a predetermined process on a web or a sheet. Any device that needs to detect the presence or absence of a web within a predetermined range in the width direction of the web may be used. For example, the device may transfer foil, ink, etc. from a web to an article other than a sheet. The device is not limited to a device that transfers foil, ink, etc. held by a web, and may also be used in a device that cleans or polishes the surface of an article using a web. [Explanation of symbols]

[0121] 10 printing system, 52 web, 68 first sensor, 70 second sensor.

Claims

1. A sensor; a control device that determines an actual presence range within a possible presence range in a width direction of the web transported by roll-to-roll based on a detection result by the sensor; 1. A web detection device comprising:

2. 2. The web detection device of claim 1, wherein the sensor scans in the width direction.

3. The web detection device of claim 2 , wherein the sensor scans over the entire range of possibilities.

4. A predetermined treatment is applied to the sheet adjacent to and parallel to the web from the web, The web detection device described in any one of claims 1 to 3, characterized in that the control device determines whether a processing range, which is the range of the sheet in which the specified processing is performed, falls within the existence range when viewed in the transport direction, which is the direction in which the sheet is transported.

5. The sheet is coated with ultraviolet-curable varnish based on varnish data that defines the coated area, and the predetermined treatment is performed on the area coated with the ultraviolet-curable varnish. The web detection device according to claim 4 , wherein the control device specifies the treatment area based on the varnish data.

6. 6. The web detection device according to claim 4, wherein the control device specifies a width of a portion of the existence range that does not overlap with the processing range in the width direction.

7. The web is a foil-bearing film having a foil laminated to the film; 7. A web detection apparatus according to claim 4, wherein the predetermined process is the transfer of a foil from the web to the sheet.

8. 8. The web detection device according to claim 1, wherein the sensor is a distance measuring sensor provided radially outside a winding roll from which the web is wound.

9. 9. The web detection device according to claim 8, wherein the control device estimates the remaining amount of the web based on a distance detected by the sensor from the sensor to an outer circumferential surface of the unwind roll.

10. The web detection device according to claim 9 , wherein the control device estimates the remaining amount of the unwinding roll in consideration of a diameter of an unwinding shaft that supports the unwinding roll.

11. 7. The web detection apparatus of claim 1, wherein the sensor detects the web as it is being fed.

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