JPS6128513B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a transfer film supply device in a thermal transfer machine, and is intended to enable a long transfer film to be used without waste at all times under appropriate tension. .

By the way, the outer surface of the three-dimensional article, especially the two
A thermal transfer machine is used when continuous transfer is to be performed on an outer surface that extends beyond the surface of the object. A transfer roller heated by a heat source is pressed against the outer circumferential surface of the article, that is, the surface to be transferred, and rotated together, and a long transfer film is sandwiched between the two, and the film is rotated by the rotation of the article. Accordingly, the article is configured to pass at a speed equal to the circumferential speed of the article, that is, the transfer speed.

The transfer film used in such thermal transfer machines has a structure in which a transfer foil and a heat-sensitive adhesive are sequentially layered on one side of a film base with a release agent layer interposed between them. When pressure is applied to the surface to be transferred, the transfer foil in that portion is transferred to the surface to be transferred by the adhesive layer only from the pressed portion. However, the transfer foil transferred as described above is left on the transfer surface by peeling off the film base using the winding of the used film. It is necessary to take care not to damage the transferred transfer foil. To do this, it is necessary to wait until the transfer film heated by the transfer roller cools down to a certain degree and the adhesive layer solidifies.
have to wait.

Therefore, normally, when the used film is wound up with the intention of peeling off the film base, the transfer film is pressed onto the surface to be transferred by the transfer roller and left on that surface for a while. , with a slight time delay. However, if you do so, even after the transfer to the transfer surface is completed,
Due to the need to subsequently strip the film base from the transfer area, the used film has to be further wound up, which unavoidably results in the unused film being unwound anew. Therefore, in the next transfer, the unused portion of the transfer film that has been pulled out in excess remains as it is, and the next transfer is started. That is, as shown in FIG.
Between the used parts L and L, which have been transferred to others, an unused part is acidified for a long time, and this unused part is wound up without being reused. Such a situation is extremely undesirable because it unnecessarily increases the amount of transfer film used, resulting in a lot of waste and an increase in transfer costs.

Therefore, the present inventor has already proposed a transfer film supply method in which a long transfer film can be used without waste in Patent Application No. 45689 of 1974. In other words, this feeding method is used to remove the film base of the used transfer film from the surface to be transferred, so that even after the transfer is completed, the unused transfer film is continuously pulled out from the feeding side. It is characterized in that it is rewound toward the feeding side.

However, when carrying out the above-described supply method, it is necessary to keep the tension of the unused transfer film at an appropriate level at all times, not only when it is pulled out from the feeding side, but also when it is rewound to the feeding side. If there is too much or too little, the film will sag or stretch, and even wrinkle, making it impossible to perform good transfer.

On the other hand, as a means of applying the required tension to an unused transfer film, a rotational force in the unwinding direction that is slightly larger than the rotational force required for unwinding is applied to the unwinding shaft that stores the film in a roll. , a method is adopted in which a resistance force is applied to the unused transfer film being pulled out from the shaft or rewound onto the shaft. This tension applying means is not particularly new, and has been conventionally employed in thermal transfer machines that do not rewind unused transfer film.
However, it has the following drawbacks. In other words, the outer diameter of the roll-shaped transfer film wound up on the feeding shaft gradually decreases as the film is used, so if the rotational force in the unwinding direction applied to the feeding shaft is always constant, Over time, the tension applied to the film increases until it cannot be kept within proper limits.

In order to deal with this difficulty, in the past, the tip of the detection arm was brought into pressure contact with the outer peripheral surface of the roll-shaped transfer film on the feeding shaft, and the amount of rotation of the arm was determined based on the change in the outer diameter of the roll of the film. Instead of the amount of electricity, this is used to adjust the strength of the rotational force in the rewinding direction applied to the feeding shaft. However, with such conventional countermeasures, the outer diameter of the film on the feeding shaft is mechanically detected, which tends to cause various problems, especially when unused transfers are detected at the tip of the detection arm that is pressed into contact. This does not cause inconveniences such as scratches or groove-like streaks on the film, or the detection arm getting in the way when loading the rolled transfer film onto the feeding shaft, causing the arm to go out of order. easy.

The present invention addresses the above-mentioned conventional problems and makes it possible to use a long transfer film under proper tension at all times without waste. Based on the input reference elements and the usage amount of the film that is sequentially detected for each transfer, the strength of the rotational force in the rewinding direction to be applied to the feeding shaft is calculated and corrected, and the rotational force from the feeding shaft is calculated. This arrangement allows unused transfer film to be drawn out and the excess film to be rewound to be rewound. Hereinafter, this will be explained in detail with reference to the embodiments shown in FIGS. 2 to 8.

In the figure, A is a transfer film having a transfer foil on one side of a film base A', and B is a three-dimensional object to be transferred. It is planned that both end portions are to be transferred surfaces b. It is assumed that this three-dimensional article B is held by a rotating jig 1 and rotated in the direction of the arrow by an appropriate drive source 2 so that the transfer surface b is the rotating peripheral surface. Reference numeral 3 denotes a transfer roller made of a heat-resistant elastic material such as silicone rubber, which is supported rotatably at the tip of a support mechanism 5 while being heated by an appropriate heat source 4, and is supported by an appropriate drive source 6. , transfer surface b of the three-dimensional article B
It is now possible to advance and retreat against the enemy. Therefore, the transfer film 3 is pressed against the transfer surface b of the three-dimensional article B during transfer, and is caused to rotate together with the aforementioned rotation of the article. On the other hand, the above-mentioned transfer film is placed on the feeding shaft 7,
It is loaded in advance in a rolled form, and when used, it is pulled out from the shaft, passed through a pair of upper guide rollers 8, 8, and then passed between the three-dimensional article B and the transfer roller 3. Passing through, from a pair of lower guide rollers 9, 9, a pinch roller 1
0 and the presser roller 11, and the winding shaft 1
2. It goes without saying that care must be taken when using the transfer film A at this time so that the transfer foil a faces the transfer surface b of the three-dimensional article B. However, the above-mentioned unwinding shaft 7 is equipped with a suitable drive source 1 for applying rotational force in the unwinding direction to the unwinding shaft.
3 is connected to the pinch roller 10 via a clutch 14 that can cause slippage in the rotational direction in response to changes in load, and a pinch roller 10 is connected to the pinch roller 10 for moving the used portion of the transfer film A in the winding direction. After that, in order to be able to move in the unwinding direction by the amount of excess winding, a DC motor, for example, that can be rotated in either forward or reverse directions and that can also provide a slight braking function when stopped is used. The winding shaft 12 is connected to a drive source 15 such as a suitable drive source 16 for applying rotational force in the winding direction to the winding shaft 12.
are connected via a clutch 17 which can cause rotational slippage between them in response to load variations. In addition, the above-mentioned both clutches 1
4, 17, the latter clutch 17 for the winding shaft 12 may be of an ordinary type, but the former clutch 17 for the unwinding shaft 7
4 is of a type that can steplessly adjust the strength of the rotational force that can be transmitted according to changes in the outer diameter of the rolled transfer film A on the shaft. For example, magnetic powder is used as the transmission medium. This uses an electromagnetic clutch commonly known as a powder clutch. Furthermore, the guide rollers 8, 8 apply fluid pressure in order to keep the transfer film A away from both the three-dimensional object B and the transfer roller 3 during non-transfer, and to bring it onto the transfer surface b of the three-dimensional object during transfer. It can be moved forward and backward at any time by a drive source 18 such as a cylinder unit, and 19 is connected to the rollers 8 and 8.
A push roller is used to ensure that the transfer film A is placed on the transfer surface b of the three-dimensional object only at the start of transfer, and can be moved forward and backward at any time by a drive source 20 such as a fluid pressure cylinder unit. Reference numeral 21 denotes an electronic control unit used to control the clutch 14 of the above-mentioned feeding shaft 7 and the driving source 15 of the pinch roller 10, and 22 indicates the actual winding amount of the transfer film A onto the winding shaft 12 and the feeding shaft. This is a detector used to detect the amount of rewinding to 7. However, it is appropriate to use a type called a microprocessor as the control unit 21, but in any case, this unit 21 is used to control the roll-shaped transfer film A loaded onto the feeding shaft 7. The reference element input end 21a allows inputting in advance the total film length and roll outer diameter at the time of loading, and the predetermined winding amount and unwinding amount for each transfer as the reference element α. and the above detector 2
A detection element input terminal 21b allows the actual winding amount and unwinding amount of the transfer film A to be inputted sequentially as the detection element β outputted from the clutch 14 and the drive source 15, respectively. It is provided with control command output terminals 21c and 21d capable of giving required control commands γ and δ. This unit 21 has a function of storing the reference element α inputted in advance, a function of checking the usage amount of the transfer film A from the detection element β inputted sequentially, and a function of checking the usage amount of the transfer film A on the feeding shaft 7. The amount of change in the roll outer diameter with respect to A is determined by the reference element α
The rotational force in the unwinding direction that should be applied to the unwinding shaft 7 according to the actual roll outer diameter at that time is calculated based on the above usage amount from the film total length and roll outer diameter at the time of loading, which are input in advance as . A function to calculate the strength of the rotational force, a function to output a control command γ based on the calculation result to control the clutch 14 to correct the strength of the rotational force, and a function to control the clutch 14 to correct the strength of the rotational force, and an actual The above winding amount and unwinding amount are compared with predetermined winding amounts and unwinding amounts inputted in advance as reference elements, and a control command δ based on the result is output to control the pinch roller 10 to wind up and unwind. The drive source 15 is assumed to have a function of controlling the drive source 15 so as to rotate the drive source 15 a required number of times in the return direction. Further, as the detector 22 used in this case, a pulse encoder that can detect the actual winding amount and unwinding amount of the transfer film A from the rotation angle of the pinch roller 10 is suitable. It shall be added to this in order to interlock with the roller. Note that 23 in the figure is an element for detecting whether or not the three-dimensional article B is ready to start transfer;
Reference numeral 24 is an element for detecting whether or not the transfer to the transfer target surface b has reached the end of the transfer range. 1 or between the jig and the drive source 2, respectively, at appropriate locations.

In the above configuration, as shown in FIG. 2, the transfer film A passes from the feed shaft 7 to the upper guide roller 8, between the transfer roller 3 and the three-dimensional object B, and from the lower guide roller 9 to the pinch roller 10. and the presser roller 11, and reach the winding side 12. Further, the transfer film A at this time is kept under tension by the tension applied by the stoppage of the pinch roller 10 and the rotational force in the rewinding direction applied from the drive source 13 to the feeding shaft 7 via the electromagnetic clutch 14. shall be. On the other hand, the three-dimensional article B at this time is held stationary by the rotating jig 1, and is in a position to allow the advancing transfer roller 3 to come into contact with the starting end A of the transfer range on the outer surface as the transfer surface b. It is in.

In this state, when the upper guide roller 8 and the push roller 19 are moved forward in the direction shown by the arrow in FIG. Film A is applied to transfer surface b of three-dimensional article B as shown in FIG. At this time, the transfer film A is slightly pulled out from above the feeding shaft 7. However, when the transfer film A is attached to the transfer surface b as described above, by rewinding as described later, the end of the unused portion following the used portion during the previous transfer will be transferred to the transfer surface b. It is assumed that the area is overlapped by a slight length '' in front of the starting end 'A' of the range.

Subsequently, the transfer roller 3 is moved to a third position by the drive source 6.
The push roller 19 is moved forward in the direction shown by the arrow in the figure, and immediately after this presses against the three-dimensional article B, the push roller 19 is retreated in the direction shown by the arrow in the figure. Then, as shown in FIG. 4, the transfer roller 3 presses and heats the transfer film A to the starting end A of the transfer range on the transfer surface b, and also transfers the film A' to the film base A' that was previously used. The portion hangs down in front of the lower guide roller 9, as shown in the figure.

Thereafter, when the three-dimensional article B is rotated by the rotating jig 1 in the direction shown by the arrow in FIG. 7 Start pulling out transfer film A from above,
At this point, the transfer to the transfer target surface b starts. However, the transfer film A that has been pressurized and heated by the transfer roller 3 as described above is transferred to the transfer surface b by the heat-sensitive adhesive layer (not shown) on the transfer foil a, but the adhesive layer The transfer base A' must be peeled off until it cools down. Therefore, winding of the used film is not performed for a while after the start of transfer.

Then, after an appropriate amount of time has elapsed from the start of transcription, the fifth
As shown in the figure, when the transfer has progressed to a certain extent, the drive source 15 moves the pinch roller 10 in the winding direction.
When the used film is rotated with , film based
Only A′ begins to be stripped away. At this time, the transfer foil a' of a slight length 'a', which had been overlapped on the transfer surface b in front of the starting end a of the transfer range, was not pressurized and heated by the transfer roller 3.
As shown in the figure, the film base A' is separated from the transfer surface b. Therefore, the transfer foil a is transferred from the starting end of the transfer range on the transfer surface b, and the peeled-off film base A' is
The used film is wound onto the winding shaft 12 to which a rotational force in the winding direction is applied from the drive source 16 via the clutch 17.

In this way, the transfer to the transfer surface b progresses, and when the transfer roller 3 eventually comes into contact with the end portion B of the transfer range as shown in FIG. 6, the detection element 24 detects this situation. The transfer roller 3
move back in the direction of the arrow in the figure. Therefore, the pressure and heating of the transfer film A by the transfer roller 3 is stopped, but at this stage, the peeling off of the film base A' from the transfer surface b is not yet completed, so the used film is not wound. The taking continues,
The three-dimensional article B is also rotated further, and the unused film is still pulled out from the feeding shaft 7.

After these steps, when the film base A' is peeled off to the terminal end RO of the transfer range on the transfer surface b, the transfer film A is separated from the terminal end as shown in FIG. When the three-dimensional article B rotates once from the start of transfer and returns to the transfer start position as shown in FIG. 8, the detection element 23 detects this situation and operates to stop the rotating jig 1 and guide the upper Roller 8 is moved back. At the same time, the pinch roller 10 is also stopped. Then, as shown in FIG. 8, the transfer film A separates from the three-dimensional article B on which the transfer has been completed, and returns to the transfer start state shown in FIG. 2. However, the unused portion of the transfer film A at this time has been pulled out by an extra length -' compared to the state shown in FIG.

Then, the pinch roller 10 is rotated in the opposite direction, and the used film is rolled up onto the winding shaft 1.
2, the transfer film A is rewound onto the unwinding shaft 7 by the rotational force in the unwinding direction applied to the unwinding shaft 7 to apply tension to the transfer film A. Therefore, the unwinding length at this time is the above-mentioned extra length -'
If the transfer film A is set equal to
The state shown in the figure returns to the state shown in FIG. 2 to prepare for the next transfer.

In this way, each time one transfer is completed,
When the transfer film A is sequentially transferred to two or more three-dimensional objects B while rewinding the excess portion of the transfer film A, the used film has the following properties:
As shown in Figure 1, between the used parts L and L,
An unused part' is left behind, but this unused part is compared to the conventional unused part shown in the same figure.
much shorter.

Incidentally, the supply of the transfer film A during the above-described transfer is controlled as follows. First, regarding the roll-shaped transfer film A loaded onto the feeding shaft 7, the electronic control unit 21
The overall length of the film and the roll outer diameter at the time of loading the film, and the predetermined winding amount and unwinding amount for each transfer are input as reference elements α. If transfer is started in this state, the feeding shaft 7
Transfer film A pulled out from above is driven by drive source 1
3 through the clutch 14 to the shaft in the unwinding direction, tension is applied and tensioned. In addition, at this time, the clutch 14 receives the control command γ output from the electronic control unit 21.
The rotational force in the rewinding direction transmitted to the feeding shaft 7 is controlled to have a strength suitable for the outer diameter of the roll of the transfer film A on the shaft, and the tension of the transfer film A is made appropriate.

In this state, when the transfer has progressed to a certain extent, the pinch roller 10 is rotated in the winding direction by the drive source 15 and starts winding up the used film, but the winding amount is controlled by electronic control. It is controlled by a control command δ given from the unit 21 to the drive source 15. Further, the actual winding amount at this time is detected by the detector 22 and inputted to the above-mentioned unit 21 as the detection element β. After a predetermined amount of winding has been performed in this manner, the pinch roller 10 is driven by the drive source 15 in order to rewind the excess transfer film A that has been pulled out from the feeding shaft 7 onto the shaft. The amount of rewinding is also controlled by the control command δ given to the drive source 15, detected by the detector 22, and input to the unit 21.

However, when the transfer film A on the feeding shaft 7 is pulled out as described above or rewound onto the shaft,
The outer diameter of the roll of the transfer film A on the shaft 7 naturally varies. The amount of change in the outside diameter of the roll is determined by the winding amount and unwinding amount of the pinch roller 10, which are sequentially input as the detection element β from the detector 22 to the electronic control unit 21, and the reference element α input in advance. Based on this, the unit calculates the strength of the rotational force in the unwinding direction that should be applied to the unwinding shaft 7 under the changed roll outer diameter. This calculation result is given to the clutch 14 by changing the content of the control command γ,
By engaging the clutch, the strength of the rotational force in the rewinding direction transmitted to the payout shaft 7 is adjusted. Such amendments are
Naturally, this is to be done in such a way that the tension of the transfer film A drawn out from the feeding shaft 7 does not vary too much or too little. However, this modification is repeatedly performed based on the reference element α input in advance and the detection element β input sequentially.
Therefore, the above-mentioned tension of the transfer film A is always maintained at an appropriate level from the feed-out shaft 7 until the film is used up.

As described above, the present invention allows the unused transfer film that has been excessively pulled out from the feeding shaft in order to peel off the film base from the transfer film used for transfer to the surface to be transferred, to be removed as described above after the peeling is completed. Since the feeding device of the present invention is rewound onto the feeding shaft, compared to conventional devices, the transfer film can be used without waste, and the amount of expensive film used can be reduced to the necessary minimum. The effect of reducing the transfer cost by that much can be expected. The present invention also provides the following characteristics: the roll outer diameter and film length of the roll-shaped transfer film loaded onto the feeding shaft at the beginning of loading; the winding amount of the used transfer film; and the unwinding amount of the unused transfer film that has been unused. Therefore, the strength of the rotational force in the unwinding direction that is constantly applied to the unwinding shaft is calculated and corrected in order to adapt it to the ever-changing roll outer diameter. , the tension of the transfer film being pulled out from the feeding shaft,
During both pulling out and rewinding, the film can be kept within an appropriate range without stretching or wrinkling the film, allowing for good transfer and ensuring that the film does not slip out of the roll. Compared to the conventional method in which changes in diameter are detected mechanically, the present invention can be expected to have the following effects: there is no risk of damaging the unused portion of the transfer film, and the loading of the roll-shaped transfer film is not hindered.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing a conventional used transfer film, the same figure is a plan view of a used transfer film in an embodiment of the present invention, and Figs. FIG. A... Transfer film, B... Three-dimensional article, b...
Transferred surface, 7... Feeding shaft, 10... Pinch roller, 1... Winding shaft, 13, 15... Drive source, 1
4... Electromagnetic clutch, 21... Electronic control unit, 22... Detector.

Claims (1)

[Claims] 1. A feeding shaft into which a long transfer film used for transferring a target article onto a surface to be transferred is loaded in the form of a roll, a drive source for applying rotational force in the unwinding direction to the shaft, and a drive source between the two. a rotational force transmitting means capable of causing slippage in the rotational direction according to changes in load and adjusting the strength of the rotational force transmitted to the feeding shaft; A pinch roller for moving the transfer film used for transfer to the winding side and then rewinding the excess unused transfer film to the feeding shaft, and rotating the roller in the winding direction and the unwinding direction. an electronic control unit for controlling the drive source for the rotational force transmitting means and the pinch roller, and detecting the amount of winding of the transfer film to the winding side and the amount of rewinding to the feeding shaft. The electronic control unit is provided with a detector for detecting the transfer film, and the electronic control unit is sequentially inputted from the detector as well as the total film length and roll outer diameter at the time of loading, which are input in advance regarding the rolled transfer film on the feeding shaft. A function that calculates the amount of change in the roll outer diameter based on the winding amount and the unwinding amount, and the above-mentioned rotational force transmission in order to adapt the strength of the rotational force in the unwinding direction applied to the unwinding shaft to the changed roll outer diameter. A transfer film supply device for a thermal transfer machine, characterized in that it is equipped with a function of controlling means.