This application claims priority from Japanese Patent Application No. 2007-243808, which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a technique of transferring gold foil, embossed patterns, hologram patterns, and the like on printed sheets of paper by pressing a transfer film thereon, thereby to increase added value of the printed surfaces, and more particularly, to a method and a device directed to transfer printing on printed sheets of paper for transferring patterns of a transfer film at predetermined positions on the printed sheets in the transfer printing.
2. Related Art
There is proposed a gloss finishing apparatus for providing added value to printed sheets of paper in the above-mentioned manner. The apparatus includes a varnishing unit that applies an ultraviolet curable resin varnish (also simply referred to as “a varnish”) onto the printed sheets of paper printed in a printing unit and a hologram forming unit of an endless type that presses a transfer film onto the printed sheets of paper varnished in the varnishing unit to transfer patterns of the transfer film thereon. With this apparatus, the hologram surface of the endlessly moving transfer film is impressed onto the surface of each of the successively fed printed sheets, whereby the patterns are transferred on the printed sheets (e.g., see Japanese Unexamined Patent Publication No. 2006-315229 (cf. FIGS. 1 and 2).
In the gloss finishing apparatus according to Japanese Unexamined Patent Publication No. 2006-315229, while the transfer film of an endless reel is pressed onto printed sheets every time a sheet is fed, the apparatus does not include a structure adapted to match the positions of the patterns of the transfer film to be transferred onto the printed sheets to predetermined positions, which makes the apparatus hard to use, being unable to transfer the patterns at predetermined positions on the printed sheets or to transfer the patterns at the same position on every printed sheet.
It may be possible to roughly decide positions to be transfer-printed at manually tuned timing, and then to transfer the patterns of the transfer film at approximately the same positions on multiple printed sheets; however, the transfer-printed positions on the printed sheets sometimes change over time, and no means for correcting the change is provided, which poses a significant problem in using the apparatus, thus calling for improvement.
In order to overcome the foregoing problems, it is an object of the present invention to provide a method and a device for performing transfer printing on printed sheets of paper, capable of reliably transferring patterns at predetermined positions on the printed sheets.
According to one aspect of the present invention, there is provided a method of performing transfer printing on a printed sheet of paper, the method including: conveying the printed sheet of paper; conveying a transfer film; and transferring a pattern of the transfer film onto the printed sheet in a repetitive manner, wherein the transfer film is applied with tension in such a manner that the tension is adjusted to stretch and contract the transfer film in a conveying direction thereof, and thereby the pattern of the transfer film is transferred at a predetermined position on the printed sheet.
According to another aspect of the present invention, there is provided a device for performing transfer printing on a printed sheet of paper, the device including a transfer section that conveys the printed sheet of paper as well as a transfer film and transfers a pattern of the transfer film onto the printed sheet in a repetitive manner, and a tension adjusting part that applies tension to the transfer film and adjusts the tension on the transfer film, to transfer the pattern of the transfer film at a predetermined position on the printed sheet.
Since the conveying speed of the transfer film can be accelerated and decelerated through the adjustment of tension on the transfer film, the patterns of the transfer film can be transferred at predetermined positions on the fed printed sheets.
The patterns to be transferred onto the printed sheets may include embossed patterns, hologram patterns, as well as gold foil.
Marks provided on the transfer film at predetermined intervals may be used so that an interval between the marks is detected, and the tension adjustment may be performed when the interval is outside a predetermined interval.
An adjustment range of the tension on the transfer film may be set from an upper limit at which the film no longer stretches and a lower limit at which the film loosens, and in a case where a position of the film fails in being matched with respect to the printed sheet within the adjustment range, a feeding speed of the film may be accelerated or decelerated.
The transfer film may be provided with marks at predetermined intervals, and the device may further include: a position detecting part that detects an interval between the marks; a determining part that determines whether or not the interval detected at the position detecting part is equal to a predetermined interval; and a driving part that drives and controls the tension adjusting part when the determining part determines a mismatch between the detected interval and the predetermined interval. In a case where the interval detected at the position detecting part is outside a predetermined interval, the driving part may drive and control the tension adjusting part to automatically carry out the tension adjustment.
The tension adjusting part may be made up of a pair of first rollers on a leading end side in a feeding direction of the transfer film, a pair of second rollers on a terminal end side in the feeding direction of the transfer film, and electric motors that drive at least two of the rollers respectively wherein the two electric motors are driven in such a manner that a difference in rotation speed is produced between the first rollers and the second rollers, to adjust the tension on the transfer film.
The device may further include a synchronous operation controlling part that changes the rotation speed of the pair of first rollers in accordance with a change in conveying speed of the printed sheet after an adjustment by the tension adjusting part, and also changes the rotation speed of the pair of second rollers by a degree that corresponds to the change in rotation speed of the first rollers.
There can be provided a method and a device for matching the position of a transfer film with respect to printed sheets of paper, capable not only of reliably transferring patterns of the transfer film at predetermined positions on fed printed sheets by adjusting tension on the transfer films but also of reliably transferring the patterns at desired positions on the printed sheets even in a case where the positions of the patterns relative to the printed sheets deviate, by immediately correcting the positions through the adjustment of tension.
The marks provided on the transfer film at predetermined intervals are used so that an interval between the marks is detected, and in a case where the interval is outside a predetermined interval, the tension adjustment is performed; with this configuration, deviation of the position of a pattern can be immediately recognized, and the position can be corrected through the tension adjustment.
In the case where the position of the film cannot be matched relative to the printed sheets within the adjustment range, the feeding speed of the film is accelerated or decelerated, so that the position matching control can advantageously be continued, and the transfer operation can be performed efficiently.
In the case where the tension adjusting part is made up of the pair of first rollers on the leading end side in the feeding direction of the transfer film, the pair of second rollers on the terminal end side in the feeding direction of the transfer film, and the electric motors that drive at least two of the rollers respectively, wherein the tension on the transfer film is adjusted by driving the two electric motors in such a way that a difference in rotation speed is produced between the first rollers and the second rollers, it is possible to downsize the device as compared with, e.g., a device that includes a stretching and contracting mechanism configured to adjust tension by operating a pair of rollers in the stretching/contracting direction of a transfer film.
In the case where the device includes the synchronous operation controlling part that changes the rotation speed of the pair of first rollers in accordance with a change in conveying speed of the printed sheets after an adjustment by the tension adjusting part, as well as the rotation speed of the second rollers by a degree that corresponds to the change in rotation speed of the first rollers, the rotation speed of the second rollers can be changed likewise with the change in rotation speed of the first rollers, and even when the conveying speed of the printed sheets has changed, the transfer operation can be performed with the position of the transfer film matched to the positions of the printed sheets without deviation at all times.
The above, and other objects, features and advantages of the present invention will become apparent from the detailed description thereof in conjunction with the accompanying drawings wherein.
In the case of attaching gold foil to the printed surfaces, a foil applicator called a toiler is used to press printed material, so that gold foil is peeled off from a substrate onto a portion with an adhesive material (or may be varnish) of the printed material attached thereto. The printed surfaces may also be applied with something other than gold foil.
The printing units 8 to 12 include, respectively, printing impression cylinders 8A to 12A as well as delivery cylinders 8B to 12B on the respective upstream sides of the printing impression cylinders 8A to 12A in a conveying direction, for delivering sheets 2 to the printing impression cylinders. The delivery cylinder 8B that has a smaller diameter and locates at the leading end in the conveying direction out of the delivery cylinders 8B to 12B is also referred to as a sheet feeder cylinder, and this delivery cylinder 8B, together with the feeder device, sheet separator device, and the like, constitutes the sheet feeder section 1. Although not shown in the figure, each of the impression cylinders 8A to 12A and the delivery cylinders 9B to 12B is provided with grippers, each having a jaw block and a gripping jaw to grip a fed sheet 2, at two positions (although only one position is shown in
A delivery cylinder 14 is provided to deliver sheets 2 to the impression cylinder 4B. Although not shown, each of these cylinders 14 and 4B is also provided with grippers, each having a jaw block and a gripping jaw to grip a fed sheet 2, at two positions (one gripper may also be provided at a single position or more than two grippers may also be provided at more than two positions) in the circumferential direction, as with the above cylinders.
As shown in
As shown in
The transfer device 6 includes a device for matching the position of the transfer film with respect to the sheets so that the patterns of the transfer film can be transferred at predetermined positions on the fed sheets 2. Specifically, as shown in
As shown in
Further, as shown in
The tension adjusting part T includes the pair of first rollers R9 and R10, the pair of second rollers R5 and R6, and the electric motors 28 and 30. The first rollers R9 and R10 are disposed side by side horizontally (may be disposed in any way) on the starting end (leading end) side in the feeding direction of the transfer film 5. The second rollers R5 and R6 are disposed side by side horizontally (may be disposed in any way) on the terminal end side in the feeding direction of the transfer film 5. The electric motors 28 and 30 drive the two rollers R9 and R5, respectively. Accordingly, the electric motors 28 and 30 are driven through the driving part 27 such that, in a case where the interval between the marks 23 that have been detected at the position detecting part 25 is longer than a predetermined interval, the rotation speed of the first rollers R9 and R10 is adjusted to be substantially equal to the rotation speed of the second rollers R5 and R6, and in a case where the detected interval is shorter than the predetermined interval, the rotation speed of the second rollers R5 and R6 is adjusted to be slower than the rotation speed of the first rollers R9 and R10, in which way the part for adjusting tension on the transfer film 5 is configured. Since the tension adjustment as described above is performed, the pitch among the marks 23 is set smaller than the size of the sheets 2 in the conveying direction; meanwhile, since the transfer film 5 is stretched by the tension adjusting part T when fed, the rotation speed of the second rollers R5 and R6 is set slightly slower than the rotation speed of the first rollers R9 and R10. Through the above-described tension adjustment, the position of the transfer film 5 is adjusted relative to the sheets 2.
More specifically, a pulley of the first roller R9 is interlockingly operated with a pulley of the first electric motor 28 through a timing belt 29 (may be chain interlock or gear interlock), and the drive of the first electric motor 28 is controlled, whereby the rotation speed of the first roller R9 can be changed. Further, as with the first roller R9, the second roller R5 is designed, such that a pulley of the second roller R5 is interlockingly operated with a pulley of the second electric motor 30 through a timing belt 31 (may be chain interlock or gear interlock), and the drive of the second electric motor 30 is controlled, whereby the rotation speed of the second roller R5 can be changed. In the case where the tension is adjusted using the tension adjusting part T configured as above, for instance, the marks 23 on the transfer film 5 are sequentially detected, namely the interval between two marks 23 or the time from the detection of a mark to the passage of a subsequent mark is calculated by a calculating part (not shown) included in the controller U, and the determining part 26 compares the calculated interval between the marks 23 or the time taken for the passage with an interval or a time taken for passage that has been stored in advance; in the case of mismatch, e.g., in the case where the detected interval or time is shorter than the interval or time stored in advance, the determining part 26 determines that the conveying speed of the transfer film 5 is too fast, and deceleration signals are outputted from the driving part 27 to the second electric motor 30 so as to decelerate the rotation speed of the second roller R5 with respect to the rotation speed of the first roller R9. In contrast, in the case where the determining part 26 determines the speed is too slow, acceleration signals are outputted from the driving part 27 to the second electric motor 30 so as to accelerate the rotation speed of the second roller R5. While the present embodiment illustrates an example of driving only the rollers R9 and the R5, which are ones of the pairs of rollers R9 and R10 and rollers R5 and R6, both the paired rollers may be driven. The conveying speed of the transfer film 5 is controlled in the above-described manner, thereby matching the sheets 2 and the transfer film 5 in time at the position where a sheet 2 that has been received by a gripping jaw of the impression cylinder 19 meets the transfer film 5. In place of the impression cylinder 19, it is possible to use a belt conveyor, a roller conveyer, or the like.
The range of the tension adjustment performed by the tension adjusting part T is set from an upper limit at which the film 5 can no longer stretch to a lower limit at which the film 5 loosens. If the intervals among the marks cannot be matched to the predetermined interval within the adjustment range, namely, only by means of the speed difference between the rotation speed of the first roller R9 and that of the second roller R5, a speed accelerating/decelerating part 32 included in the controller U accelerates/decelerates the feeding speed of the film 5. In other words, the conveying speed of the transfer film 5 is merely caused to be slower or faster than a predetermined speed with the adjustment by the driving part 27 alone, and the intervals among the marks cannot be matched to the predetermined interval no matter how long the time passes. Even in such a case, the intervals can be matched to each other through acceleration signals and deceleration signals outputted from the speed accelerating/decelerating part 32 to the first and second electric motors 28 and 30. When the acceleration signals or deceleration signals outputted to the first and second electric motors 28 and 30 successfully make the intervals among the marks match the predetermined interval, the driving part 27 drives and controls the tension adjusting part T to return to the tension adjustment control. The determination that the intervals among the marks cannot be matched to the predetermined interval may be made in such a case that the intervals among the marks were unable to be matched to the predetermined interval even when the tension adjustment by the tension adjusting part T was performed twice (may be more than twice). While the example herein shows the case in which the tension adjustment is automatically controlled based on the information detected by the position detecting part 25, the speed of the electric motor 30 may be adjusted through manual operation when deviation of the transferred positions of the transfer film on the printed sheets is visually confirmed, or alternatively, the visual confirmation may be conducted by the position detecting part 25, and based on the information detected by the position detecting part 25, the speed of the electric motor 30 may be adjusted through manual operation.
As shown in
As shown in FIG, 2, the transfer section F, which is comprised of the pressing rollers 15 and 16 and the transfer film 5 carried between the pressing rollers 15 and 16, is freely movable between a remote position (shown with a chain double-dashed line) and a proximate position (shown with a solid line) relative to the impression cylinder 19, and, e.g., in the case where the transfer operation is not performed, the transfer section F can be located at the upward-receded position.
A driving part is provided to move the transfer section F away from towards the impression cylinder 19. As shown in
The sheet discharge section 7 includes a conveyor device for receiving the sheets 2 that have been processed in the processing devices and conveyed thereto, and conveying them to a predetermined position. The conveyor device is provided over a pair of right and left endless running chains 7C that are suspended between a pair of right and left sprockets 7A and 7B respectively. Each of the sprockets 7A and 7B is provided with grippers (although not shown, the basic structures thereof are the same as the above-described grippers) for gripping the sheets at both ends in the sheet-conveying direction (see
This specification is by no means intended to restrict the present invention to the preferred embodiments set forth therein. Various modifications to the method and device for performing transfer printing, as described herein, may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.
Number | Date | Country | Kind |
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2007-243808 | Sep 2007 | JP | national |