JPH0438665B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for positioning a belt-shaped transfer film used in, for example, a thermal transfer device, a simultaneous molding transfer device, etc., or a belt-shaped object such as other films or tapes.

(Prior art) For example, a thermal transfer device called a hot stamp positions a pattern on a transfer film in correspondence with an object to be transferred, and in this state presses the transfer film against the object while heating it with a transfer pad. This thermal transfer device transfers only one pitch of the transfer film when the transfer work to one object is completed. A transfer film feeding device is provided for positioning untransferred designs on the film corresponding to the next transferred object.

However, this feeding device moves the transfer film one by one.
If the transfer film is transferred pitch by pitch, if the transfer film is not correctly rolled in a predetermined positional relationship with respect to the object to be transferred, an error will occur in the transfer position of the design to the object to be transferred. Therefore, this feeding device is provided with a positioning device that stops the feeding device when an optical sensor detects an identification mark provided for each pitch on the transfer film. but,
Conventional positioning devices tend to not accurately position the transfer film at a predetermined position due to the time delay between when the sensor detects the mark and when the feeding device completely stops. Further, in order to cope with this problem, it is possible to reduce the feeding speed of the transfer film, but this will result in a significant deterioration in efficiency.

Such problems occur not only in the above-mentioned thermal transfer devices, but also in simultaneous molding transfer devices that transfer designs on a transfer film to resin products at the same time as the injection molding of the products. This phenomenon occurs not only in devices that use transfer films, but also in various devices that intermittently transport other strip-shaped films or tapes to predetermined positions.

By the way, according to Japanese Patent Application Laid-open No. 59-204522,
The following invention has been disclosed regarding positioning of a transfer film in a simultaneous molding and transfer device. That is, in this invention, two sensors are arranged at appropriate intervals along the transfer film feeding direction, and when the upstream sensor detects a mark, the feeding speed is switched from high speed to low speed, and then the upstream sensor detects a mark. The feed is stopped when a downstream sensor detects a mark, and it is expected that positioning errors due to delays in stopping the film will be reduced. However, even with such a method, there is a limit to the positioning accuracy due to the characteristics of the sensor itself, and positioning cannot be performed with higher accuracy. In other words, as shown in FIG. 7, when the slit-type mark B of the transfer film is positioned on the light-receiving surface A of the sensor, a signal is output from the sensor A. The position of mark B cannot be distinguished between position A indicated by a solid line and position B indicated by a chain line in the same figure, and errors in this range always occur.

On the other hand, as a method for detecting identification marks with higher accuracy, there is a method using a television camera. In other words, it detects the position of the mark photographed by a television camera on the image-receiving surface, and controls the feeding device in a feedback manner so that the mark is positioned at a predetermined position (generally at the center) of the image-receiving surface. According to this, positioning accuracy is significantly improved. However, this method requires expensive equipment such as a television camera and a receiver, and the television camera used as a detection means is large, so a large space is required to install the camera, and a thermal transfer device When the surrounding temperature becomes extremely high, as in the case of a television camera, there are disadvantages such as a decrease in the durability of the television camera.

(Object of the Invention) The present invention addresses the above-mentioned problems regarding the positioning of belt-shaped objects such as transfer films and various films and tapes used in thermal transfer devices, simultaneous molding transfer devices, etc. It is an object of the present invention to realize a positioning method that can use an extremely compact sensor as a sensor for detecting an identification mark provided on an object to be transported, and can perform positioning with high precision.

(Structure of the Invention) That is, the positioning means according to the present invention includes a feeding means for longitudinally transporting a belt-shaped object to be transported, and a projection that irradiates detection light to a passing position of an identification mark provided on the object to be transported. Using an optical means and a position detecting means that receives detection light that is transmitted through the mark, reflected by the mark, or partially blocked by the mark, and according to the output signal of the position detecting means. A method for controlling the operation of the feeding means, wherein the position detection means has a light receiving zone whose dimension along the feeding direction of the object to be transported is longer than the dimension of the identification mark in the same direction, and has two output terminals. A sensor is used in which the sum of the output values from the two output values corresponds to the amount of light incident on the light receiving zone, and the difference between the two output values corresponds to the amount of deviation of the light incident position or the light blocking position with respect to the center of the light receiving zone. The feeding speed of the feeding means is switched based on a change in the sum of both output values of the sensor, and the feeding means is stopped when the difference between both output values falls within a predetermined range.

More specifically, the sensor has a light receiving zone whose dimension along the feeding direction of the transferred object is longer than the dimension of the identification mark in the same direction, and the sum of the output values from the two output terminals is transmitted to the light receiving zone. corresponds to the amount of incident light, and the absolute value of the difference between both output values is +, -
A sensor is used whose sign corresponds to the amount and direction of deviation of the light incident position or the light blocking position, respectively, with respect to the center of the light receiving zone. If the identification mark is of a transmission type or a reflective type, the feeding means is operated at high speed when the sum of both output values of the sensor is less than a predetermined value, and when the sum of both output values exceeds a predetermined value. When the feeding means is switched to a low-speed feeding operation, and the identification mark is a light-shielding type, the feeding means is switched to a high-speed feeding operation when the sum of both output values of the above sensor is a predetermined value or more, and when the sum of both output values is When the value becomes smaller than a predetermined value, the feeding means is switched to low-speed feeding operation, and
When the absolute value of the difference between both output values becomes less than a predetermined value, the operation is further switched to slow-speed feeding, and in this slow-speed feeding state, the absolute value of the difference is within the allowable error range according to the sign of + or - of the above-mentioned difference. The feeding means is moved forward or backward so as to converge.

In addition, if necessary, the detection light is irradiated from the light projecting means to the passing position of the identification mark on the object through the optical fiber, and the detection light transmitted through the mark or reflected by the mark is is configured to be received by a position detection means (sensor) via an optical fiber.

(Effects of the Invention) According to the above configuration, when a belt-shaped object to be transported is intermittently transferred, the object to be transported can be transported without deterioration in efficiency as would be the case when the feeding speed is constantly slowed down. It becomes possible to accurately stop the machine at a predetermined position. As a result, for example, in a thermal transfer device or a simultaneous molding transfer device, the transfer film can be positioned with high precision with respect to the object to be transferred.
This prevents the occurrence of defective products in which the transfer position of the design is misaligned, and also allows other films, tapes, etc. to be positioned accurately even in devices that transfer films, tapes, etc. intermittently. Predetermined operations on films and the like can be performed satisfactorily.

In particular, according to the present invention, the sensor for detecting the identification mark is compact, and an optical fiber can be used if necessary, so it does not require a large space unlike the case where a television camera is used. It has the advantage of being inexpensive.

(Example) Hereinafter, an example in which the present invention is applied to a thermal transfer device will be described.

First, the schematic structure of the thermal transfer device will be explained with reference to FIG. 1. The thermal transfer device 1 includes a pedestal 2 on which an object to be transferred and has. The pedestal 2 is moved up and down by a cylinder (not shown) via a support shaft 4, and after the object to be transferred X is set at a lower position, it is moved upward to the illustrated position.
Further, the transfer pad 3 is heated by an appropriate means, and is heated by a cylinder (not shown).
It is moved downward from the illustrated position via the support shaft 5 and pressed against the transferred object X on the pedestal 2.

On the other hand, this thermal transfer device 1 is equipped with a film supply device that supplies a transfer film Y between the transfer target X on the pedestal 2 and the transfer pad 3.
This supply device is composed of a film supply section 6 provided on one side of the transfer pad 3 and a film winding section 7 provided on the other side. A roll support shaft 8 that supports the roll Y', and a feed roller 1 that is driven by a feed motor 9 and feeds the transfer film Y pulled out from the roll Y' to the transfer pad 3 side.
0, and a presser roller 11 which sandwiches the transfer film Y and comes into contact with the roller 10. The film winding section 7 also includes a winding roller 12 that winds up the transferred transfer film Y, a guide roller 13 that guides the transfer film Y to the winding roller 12, and a winding roller that drives the winding roller 12. A take-up motor 14 is provided. Here, the feed motor 9 is a pulse motor capable of forward and reverse rotation, and the winding motor 14 is connected to the feed motor 9.
The winding roller 12 is driven to follow the transfer film Y that is moved forward and backward by the rollers, and thereby the transfer film Y is always kept in the required tension state between the film supply section 6 and the film winding section 7. It is starting to be retained.

However, on the transfer film Y, as shown in FIG. 2, a large number of designs Y ₁ ...Y ₁ are drawn in a row, and on one side of the film Y there is a black part Y ₂ . Slits Y 3 . . . Y ₃ as identification marks are provided in the black painted portion Y ₂ in correspondence with the respective patterns Y _{1 . .} . Y ₁ . Then, on the side of the transfer pad 3 in this thermal transfer device 1, there is a slit in the transfer film Y.
Y ₃ ...A position detector 15 is provided so as to sandwich the side where Y ₃ is provided. This position detector 15
As shown in FIG. 3, a U-shaped main body 16 is provided with a notch 16a into which the side portion of the transfer film Y is inserted, and one end portion 17a of a light emitting optical fiber 17 and a light receiving optical fiber 18 is attached. , 18a are attached to face each other on both sides of the notch 16a, and a light emitting lamp 19 is disposed facing the other end 17b of the light emitting optical fiber 17, and a light receiving light The other end 18b of the fiber 18
A sensor 20 is disposed facing each other, so that when the slit _Y3 in the transfer film Y is located between the opposing ends 17a and 18a of both optical fibers 17 and 18, the detection light projected from the lamp 19 is detected by the sensor. 20 is set to be input.

Here, to explain the characteristics of the sensor 20, the fourth
As shown in the figure, the sensor 20 is located opposite to the end 18b of the light receiving optical fiber 18.
It has a light-receiving zone 20a of a certain area that is irradiated with detection light from the sensor, and first and second terminals 20 ₁ and 20 ₂ that respectively output signals according to the light-receiving state of the zone 20a. In that case, the light receiving zone 20a
The dimension along the feeding direction of the transfer film Y is longer than the dimension of the slit _Y3 in the same direction. The sum of output values E ₁ and E ₂ from both terminals 20 ₁ and 20 ₂ corresponds to the total amount of light incident on the light receiving zone 20a, and both output values E ₁ and E ₂ correspond to the amount of light incident on the light receiving zone 20a, respectively. For example, as shown in FIG. 4a, when the light incident position x, that is, the slit _Y3 of the transfer film Y is offset to one side of the light receiving zone 20a, terminal 2 of
The output value E ₁ from 0 ₁ becomes larger, and the output value E ₂ from the opposite terminal 20 ₂ becomes smaller, as a result,
E ₁ >E ₂ , and when the light incident position x is deviated to the opposite side as shown in b of the figure, E ₁ <E ₂ .
Then, the magnitude of the difference ΔE=E ₁ −E ₂ between both output values E ₁ and E ₂ corresponds to the amount of deviation of the light receiving zone 20a from the center line y, and its + and − signs correspond to the direction of deviation. It's becoming like that. Therefore, when the light incident position x coincides with the center line y of the light _- receiving zone 20a, as shown in _FIG .

The operation of the feed motor 9 is controlled in accordance with the output of the sensor 20, and the configuration of the control circuit that performs this control will be described next.

As shown in FIG. 5, this control circuit receives the two output signals a _{1 and a 2 of} the sensor ₂₀ and outputs the sum ( _or An amplifier 21 that calculates the average value) E and outputs it as an addition signal b, and an output signal of the sensor 20 as well.
When a ₁ and a ₂ are input, the difference ΔE between both output values E ₁ and E ₂ (=E ₁
-E ₂ ) and outputs it as a subtraction signal c; a high-speed feed determiner 23 to which the addition signal b is input; and a low-speed feed judger 23 to which the addition signal b and the subtraction signal c are input. Slow feed determiner 24
and a feed direction determiner 25 to which the subtraction signal c is input.
and has. Then, the high speed feed determination device 23
is, when the value E indicated by the addition signal b is less than the predetermined value _E0 ,
That is, when the amount of light incident on the light receiving zone 20a of the sensor 20 is less than a predetermined amount, the high speed sending signal d is output. This signal d is inputted to the enable terminal of a high-frequency oscillator 28 for high-speed feed through a waveform shaper 26 and a feed amount detector 27 that detects the feed amount from the output time of the signal d, and is activated to operate the oscillator 28 to provide a high-speed The sending pulse signal e is output, and the gate 30 on the output circuit 29 of the signal e is opened.

Furthermore, when the value E indicated by the addition signal b exceeds a predetermined value _E0 , the low-speed slow-speed feed determiner 24 detects that the sensor 2
When the amount of light incident on the light-receiving zone 20a of 0 exceeds a predetermined amount, a low-speed, slow-speed feed signal f is output, and when the value ΔE indicated by the above-mentioned subtraction signal c becomes less than the predetermined value ΔE ₀ , that is, when the amount of light incident on the light-receiving zone 20a exceeds a predetermined amount, A switching signal g is output when the amount of deviation of the light incident position with respect to the center becomes less than a predetermined amount. Then, the low speed fine speed feed signal f
is inputted to the enable terminal of the low-frequency oscillator 33 for low-speed fine-speed feed via the waveform shaper 31 and the high-speed feed completion detector 32 which detects that high-speed feed is completed since the signal f is output. The oscillator 33 is operated to output a low/very slow pulse signal h, and the switching signal g is input to the switching terminal of the oscillator 33 to switch the frequency of the pulse signal h from a low frequency to an extremely low frequency. Here, the output circuit 34 for the low-speed slow pulse signal h is provided with a gate 36 to which the high-speed feed signal d is inputted via an inverter 35. Therefore, the pulse signal h is output only when the high-speed feed signal d is OFF.

Further, the sending signal determiner 25 receives the subtraction signal cga
A direction command signal i instructing forward rotation or reverse rotation is output depending on the + or - sign of the indicated value ΔE. A gate 39 is also provided on the output circuit 37 for this signal i to which the high-speed feed signal d is inputted via the inverter 38, so that the direction command signal i is output only when the high-speed feed signal d is OFF. will be done.

Then, the output circuits 29 and 34 of the high frequency oscillator 28 and the low frequency oscillator 33 and the feed direction determiner 2
The output circuit 37 of No. 5 is connected to the feed motor 9 via the driver 40, and the motor 9 responds to the pulse signals e, h and the direction command signal i input through the output circuits 29, 34, and 37. It is designed to be rotationally driven. Here, a manual high-speed feed signal j for manually high-speed feeding is input to the enable terminal of the high-frequency oscillator 28, and a manual low-speed signal j for manually causing low-speed or slow-speed feed is input to the enable terminal of the low-frequency oscillator 33. A slow feed signal k is input. Furthermore, a manual direction changeover switch 41 is provided, and when the gate 43 provided in the output circuit 42 of the switch 41 is opened by the high speed feed signal d, the feed direction command signal l is manually output. It is becoming possible to do this.

Next, a method for positioning the transfer film Y using the above-mentioned apparatus will be explained with reference to the flowchart of FIG.

First, when a film feed command is output with the transferred object X set on the pedestal 2 and the transfer pad 3 retracted upward, high-speed feeding of the transfer film Y is started (as shown in FIG. 6). Step _S1 ). This high-speed feeding is performed by rotating the feeding motor 9 at high speed in a predetermined feeding direction by a high-frequency pulse signal e outputted from the high-frequency oscillator 28 in response to the high-speed feeding signal d. The transferred part is sent out to the film winding section 7 side, and the next untransferred pattern is sent out to the film winding section 7 side.
The portion _Y1 is sent between the object to be transferred X and the transfer pad 3. When this pattern _Y1 is transferred to a position where it has a predetermined positional relationship with respect to the transferred object X, the slit _Y3 on one side of the film Y reaches the installation position of the position detector 15,
The detection light emitted from the lamp 19 enters the sensor 20 via the light emitting optical fiber 17, the slit _Y3 , and the light receiving optical fiber 18 (step _S2 ). As a result, the sum E of the output values E ₁ and E ₂ indicated by the output signals a ₁ and a ₂ of the sensor 20 is set to a predetermined value.
E becomes larger than ₀ , and the above high-speed feed signal d turns OFF.
At the same time, the low-speed fine-speed feed signal f is output, the low-frequency oscillator 28 is activated, and the motor 9 starts to rotate at a low speed due to the low-frequency pulse signal h output from the oscillator 28 (step S ₃ ). . When the difference ΔE between the output values E ₁ and E ₂ becomes equal to or less than the predetermined value ΔE ₀ , that is, when the slit Y ₃ is near the center of the light receiving zone 20a of the sensor 20 (at the center of the light receiving optical fiber 18 in the position detector 15), By outputting the switching signal g when reaching the terminal 18a (near the center of the terminal 18a), the frequency of the pulse signal h output from the low frequency oscillator 33 is switched from a low frequency to an extremely low frequency, and the rotation of the motor 9 is The speed, ie, the feeding speed of the transfer film Y, is switched to a slow speed (step S ₄ ). At this time, the difference ΔE between the above output values is +, -
A feed direction command signal i is output according to the sign of
When the slit _Y3 is in front of the center line y of the light-receiving zone 20a of the sensor 20, it is advanced at a slow speed, and when it passes the center line, it is moved back at a slow speed. Then, the slit is formed within an extremely small tolerance range with respect to the center line y of the light receiving zone 20a.
When Y ₃ is located, that is, when the above-mentioned difference ΔE becomes ΔE≈0, the slow feed is stopped. This completes the positioning of the transfer film Y in the feeding direction (steps S ₅ and S ₆ ), but as mentioned above,
Slit Y ₃ of transfer film Y is position detector 15
The film Y is fed at high speed until it reaches the installation position of the transfer film Y, which improves efficiency, and when the slit _Y3 reaches the installation position of the position detector 15, the transfer is switched to low speed or very slow feeding. will be positioned with high precision. Therefore, if the transfer pad 3 is moved down after the feeding of the film Y is completed, the design on the film Y can be transferred.
_Y1 is transferred to the transferred object X without any deviation. In particular, according to this positioning method, the sensor 20 used as the position detection means
is compact, and by using the optical fibers 17 and 18 as in this embodiment, it can be implemented even when there is not enough space near the passing position of the transfer film Y.

In the above embodiment, the slit _Y3 was provided as an identification mark on the transfer film Y, and the sensor 20 received the detection light that passed through the slit _Y3 . The sensor may receive the detection light reflected by the mark.
In addition, the above slit is used as this identification mark.
Instead of Y ₃ , one that partially blocks the detection light may be used. In this case, contrary to the case of the slit, the identification mark is the light receiving zone 20a of the sensor 20.
The amount _of incident light decreases _{when the} position _corresponds to Although the output value from the terminal whose position is deviated is smaller than the output value from the other terminal, control based on these output values is
This can be carried out in exactly the same manner as in the previous embodiment using a slit-type identification mark.

Furthermore, if such a positioning method is applied to both the feeding direction of the transfer film and the width direction perpendicular to this direction, the design of the film will be aligned with respect to the transferred object in two directions: the feeding direction and the width direction. This means that positioning can be performed with high accuracy. Furthermore, this positioning method is applicable not only to the positioning of the transfer film in a thermal transfer device as described above, but also to the positioning of the transfer film in a simultaneous forming transfer device, or when intermittently transporting other strips such as films or tapes. It is widely applicable.

[Brief explanation of drawings]

1 to 6 show an example in which the method of the present invention is applied to a thermal transfer device. FIG. 1 is a schematic front view of the thermal transfer device, FIG. 2 is a plan view of a transfer film used in the device, and FIG. 3 is a schematic configuration diagram of the position detecting means, FIG. 4 is a diagram explaining the characteristics of the sensor in the position detecting means, FIG. 5 is a circuit diagram of a control circuit that executes the method of the present invention, and FIG. 6 is a diagram of the control circuit. It is a flowchart diagram showing operation. FIG. 7 is an explanatory diagram of problems in the prior art. 9... Feeding means (feeding motor), 17, 18...
...Optical fiber, 19... Light projecting means (lamp), 2
0...Position detecting means (sensor), 20a...Light receiving zone, ₂₀₁ , ₂₀₂ ...Terminals, Y...Transferred object (transfer film), _Y3 ...Identification mark (slit).

Claims (1)

[Scope of Claims] 1. A positioning method for stopping a belt-shaped object transported in the longitudinal direction by a feeding means at a predetermined position, the method comprising: detecting a detection light at a position where an identification mark provided on the object passes; and a position detecting means for receiving detection light transmitted through the mark, reflected by the mark, or partially blocked by the mark, and the position detecting means has a light receiving zone whose dimension along the feeding direction of the transferred object is longer than the dimension of the identification mark in the same direction, and the sum of the output values from the two output terminals corresponds to the amount of light incident on the light receiving zone,
Using a sensor in which the difference between the two output values corresponds to the amount of deviation of the light incident position or the light blocking position with respect to the center of the light receiving zone, and switching the feeding speed of the feeding means based on a change in the sum of the two output values, A method for positioning a belt-shaped object to be transported, characterized in that the feeding means is stopped when the difference between both output values falls within a predetermined range. 2 The position detection means has a light receiving zone whose dimension along the feeding direction of the transferred object is longer than the dimension of the identification mark in the same direction, and the sum of the output values from the two output terminals corresponds to the amount of light incident on the light receiving zone. In addition, using a sensor in which the absolute value of the difference between the two output values and the + and - signs correspond to the amount and direction of deviation of the light incident position or the light blocking position, respectively, with respect to the center of the light receiving zone, the identification mark is In the case of a transmission type or reflection type, when the sum of both output values of the sensor is less than a predetermined value, the feeding means is operated at high speed, and when the sum of both output values exceeds a predetermined value, the feeding means is operated at low speed. In addition, if the identification mark is a light-shielding type, the feeding means is operated at high speed when the sum of both output values of the sensor is greater than a predetermined value, and when the sum of both output values becomes smaller than the predetermined value, the feeding means is activated. is switched to low-speed feeding operation, and when the absolute value of the difference between the above two output values becomes less than a predetermined value, further switched to slow-speed feeding operation,
In the state of this slow feeding operation, the feeding means is moved forward or backward depending on the + or - sign of the difference so that the absolute value of the difference converges within an allowable error range. A method for positioning a belt-shaped object to be transported according to scope 1. 3 Irradiating the detection light from the light projecting means to the passing position of the identification mark on the object to be transported via the optical fiber, and transmitting the detection light through the mark, reflecting by the mark, or partially blocking the light by the mark. 3. A method for positioning a belt-shaped object according to claim 1, wherein the detected light is received by a position detecting means via an optical fiber.