DESCRIPTION

LAMINATING APPARATUS

Technical Field

The present invention relates to a laminating apparatus for joining a film and the like to a substrate with a laminating roller, and particularly to a laminating apparatus in which tension of a film is kept constant.

Background Art

Conventionally, a laminating apparatus is employed in a liquid-crystal production line, a semiconductor production line and so forth wherein a film and the like having photosensitivity is joined to a glass substrate, a semiconductor substrate and so forth. In the laminating apparatus, the film is superimposed on one surface of the respective substrates successively fed at predetermined intervals, and a pair of laminating rollers pinches the substrate and the film to joint them with pressure (see Japanese Patent Laid-Open Publication No. 2003-062906, for instance) .

In the laminating apparatus, the film is sent first into a passage wherein the substrate and the film are joined. When the substrate has been sent into the passage, a transport route of the film is moved to superimpose the film on the substrate. The film includes a base film, a resin layer formed on the base film to join to the substrate, and a protective layer stacked on the resin layer. The protective layer is peeled before the film is sent into the passage. The resin layer is melted by heating to tightly adhere to the substrate. However, the resin layer has adhesion also in a state that the protective layer is peeled at room temperature. Due to this, the resin layer adheres to a

carrying roller and the like coming into contact therewith.

In the laminating apparatus described in the above-noted Publication No. 2003-062906, a suction drum is disposed at an upstream side of a laminating roller. The suction drum draws the film and rotates in a film-carrying direction and in a reverse direction thereof to stabilize tension of the film put on the laminating roller. Meanwhile, the tension of the film is measured between the suction drum and the laminating roller. On the basis of a measurement result of the tension, a rotation speed of the suction drum is regulated to keep the film tension constant.

The suction drum has a larger diameter in comparison with a roller used for carrying the film, and the inside thereof is provided with an air passage for performing air aspiration . Thus , the inertia moment is comparatively large. Particularly, in recent years, the suction drum employed in the laminating apparatus has a larger diameter as a liquid-crystal panel and so forth have a larger screen. Consequently, the inertia moment further increases. The above-noted Publication No. 2003-062906 does not disclose how to change the rotation speed of the suction drum. However, when a rotation speed of a motor rotating the suction drum is regulated, a time lag occurs until the rotation speed of the suction drum is actually changed after regulating the rotation speed of the motor. Due to this , there arise problems in that wrinkles and so forth are caused by unstable fluctuation of the film tension during the time lag and laminate quality deteriorates. Further, there arise other problems in that the film flaps due to the fluctuation of the tension and feeding the substrate is disturbed.

A primary object of the present invention is to provide a laminating apparatus in which tension of a film is kept constant between a suction drum and a laminating roller.

Disclosure of Invention

In order to achieve the above objects and other objects, the laminating apparatus according to the present invention comprises a laminating roller and a tension roller. The laminating roller joins a film to a substrate by carrying and pressing the substrate and the film. The tension roller is disposed at an upstream side of the laminating roller in a carrying direction of the film to apply tension to the film. Between the tension roller and a motor for rotating the tension roller, a torque regulator intervenes to regulate torque to be transmitted from the motor to the tension roller. Meanwhile, a device for measuring the tension of the film is disposed at a film transport route extending between the tension roller and the laminating roller. On the basis of the measured tension, the torque regulator is controlled by a tension controller to control the tension of the film.

As the tension roller, a roller rotating in a direction opposite to the carrying direction of the film may be used. In order to increase the tension applied by the tension roller, a circumferential surface thereof may suction the film.

As the torque regulator, a clutch for regulating the torque, which is transmitted from the motor to the tension roller, is suitable. Further, as the clutch, a powder clutch is suitable because it is possible to rapidly and accurately control the transmission torque.

The tension controller comprises a torque calculator and a drive-signal producer. The torque calculator compares the torque measured by the tension measuring device, with preset reference tension to calculate torque necessary for the tension roller. On the basis of the calculated torque, the drive-signal producer produces a drive signal of the torque regulator. Incidentally, the torque calculator may calculate the torque of

the tension roller necessary for equalizing the measured tension with the reference tension.

In a preferred embodiment, the laminating apparatus further comprises a carrying mechanism and a torque changer . The carrying mechanism carries only the film or both of the film and the substrate . The carrying mechanism enables a carry speed to change between a film-carrying speed set at a time when only the film passes the laminating roller, and a joining speed set at a time when the substrate and the film are joined. The torque changer changes the transmission torque of the torque regulator by inputting a torque instruction into the tension controller when the carrying mechanism changes the carry speed.

In changing the transmission torque of the torque regulator, when the joining speed is faster than the film-carrying speed, the transmission torque of the torque regulator is decreased at an acceleration period during which the film-carrying speed is changed to the joining speed. In contrast, the transmission torque of the torque regulator is increased at a deceleration period during which the joining speed is changed to the film-carrying speed.

When a route changer for changing the transport route of the film is disposed at the upstream side of the laminating roller, it is preferable to provide an actuator for moving the tension measuring device in a direction substantially perpendicular to the transport route of the film. Although a transport-route length of the film changes due to the change of the transport route performed by the route changer, the actuator moves the tension measuring device in accordance with the operation of the route changer so that the transport-route length of the film is kept constant.

The film includes a base film and a photosensitive resin layer formed on the base film. After joining the film to the

substrate, the base film is peeled from the substrate in a state that the photosensitive resin layer is transferred to the substrate.

According to the laminating apparatus of the present invention, it is possible to more rapidly change the torque of the tension roller in comparison with a case in that a rotation speed of a motor is changed. Moreover, it is possible to shorten an unstable period at the time of the tension change. Further, since the tension applied to the film is kept constant, it is possible to prevent a defect from being caused due to fluctuation of the tension.

As to the torque regulator, it is possible to utilize a clutch of a powder clutch and so forth. In virtue of this, it is possible to correctly regulate the torque at comparatively lower cost.

Further, since the transmission torque of the torque regulator is changed in accordance with the change of the carry speeds of the film and the substrate, it is possible to accurately compensate the film-tension fluctuation caused by the change of the carry speed.

Furthermore, since the transport-route length of the film is kept constant even when the transport route of the film is changed at the joining time of the film and the substrate, it is possible to properly measure the film tension.

Brief Description of Drawings

Figure 1 is a perspective view showing a film and a substrate joined by the laminating apparatus according to the present invention; Figure 2 is a section view showing a layer structure of the film;

Figures 3A to 3F are illustrations showing a joining

procedure of the laminating apparatus;

Figure 4 is a schematic illustration showing a structure of the laminating apparatus;

Figure 5 is a schematic illustration showing an adjacent structure of a suction drum;

Figures 6A and 6B are schematic illustrations showing a structure of a joining area;

Figures 7A and 7B are timing charts showing timing of a carry-speed changeover and a torque instruction; Figure 8 is a flowchart showing a joining process of the laminating apparatus; and

Figure 9 is a schematic illustration showing an adjacent structure of a suction drum of another laminating apparatus in which transmission torque of a powder clutch is regulated by a torque instruction of a PLC.

Best Mode for Carrying Out the Invention

Fig. 1 is a perspective view showing a substrate 2 to which a film is joined by the laminating method according to the present invention. The substrate 2 is a thin plate made of transparent glass and plastic, for instance, and is a base of a color filter employed in a liquid-crystal display, a plasma display and so forth. Reference numeral 9 denotes a photosensitive resin layer composing the color filter. The photosensitive resin layer 9 is a part of a film 3 (see Fig. 2) to be joined to the substrate 2. After joining the photosensitive resin layer 9 to the substrate 2, a predetermined pattern is left on the substrate 2 by exposure, development and cleaning to compose the color filter.

Incidentally, if the photosensitive resin layer 9 adheres to a lateral side of the substrate 2, a no-good product is caused. In view of this , a joining area of the photosensitive resin layer 9 is adapted to be smaller than the substrate 2. Consequently,

a joining surface of the substrate 2 is exposed around the photosensitive resin layer 9 so as to have a frame-like shape. Hereinafter, this frame-shaped portion is referred to as an outer frame 2a. Figs. 3A to 3F are illustrations showing a procedure for joining the film 3 to the substrate 2. Fig. 3A shows an external shape of the film 3, which is a strip of film and is wound as a film roll 6 to be set to the laminating apparatus. As shown in the section view of Fig. 2, the film 3 is a layered product including the photosensitive resin layer and having a multilayer structure in which plural layers are stacked. The film 3 is composed of a base film 8, the photosensitive resin layer 9 and a protective film 10 stacked in this order from the bottom. Since the respective layers have flexibility, these layers are not damaged even though the layers are wound in the roll form.

The film 3 set to the laminating apparatus is drawn out of the film roll 6 such as shown in Fig.3B. And then, the protective film 10 is cut at two intervals of lengths Ll and L2. This process is called as half-cut process and is successively performed for the film 3 under the condition that the two intervals Ll and L2 are alternately used. The interval Ll is a joining length of the photosensitive resin layer 9 to be joined to the substrate 2. The interval L2 defines a half-cut interval between areas of the joining length Ll. Although the protective film 10 becomes a sheet-like shape by the half-cut process, the protective film 10 stays on the photosensitive resin layer 9 without peeling therefrom. Hereinafter, the portion for which the half-cut process has been performed is referred to as half-cut portion 3a, and the region for which the half-cut process has been performed at the interval L2 is referred to as residual region 3b.

As shown in Fig. 3C, attachment labels 13 are attached onto the sheet-shaped protective films 10a and 10b, for which the

half-cut process has been performed, so as to straddle the residual region 3b. The attachment labels 13 are attached to a posterior end of the preceding sheet-shaped protective film 10a and an anterior end of the succeeding sheet-shaped protective film 10b. When the protective film 10 is peeled from the film 3, the protective film 10 cut in the sheet shape is continuously peeled by the attachment labels 13 in a web-like form such as shown in Fig.3D. In this regard, the attachment labels 13 are not attached to the residual region 3b for the purpose of staying the residual region 3b of the protective film 10 on the film 3 at the time when the protective film 10 is peeled.

As shown in Fig. 3E, the film 3 from which the protective film 10 is peeled is reversed and the photosensitive resin layer 9 is joined to an upper surface of the substrate 2. At the joining time, the substrate 2 and the film 3 are pressed by a pair of laminating rollers 16a and 16b. The laminating roller 16a is rotated by a motor 17 • In virtue of this , the substrate 2 and the film 3 are joined and simultaneously carried.

Meanwhile, the substrates 2 are successively fed to join with the photosensitive resin layer 9. In consideration of variation of joining accuracy, when a feeding interval of the substrates 2 is 20± 5mm and a length L3 of the outer frame 2a is

1 to 5mm in the feeding direction for instance, the half-cut interval L2 becomes a length calculated by adding the feeding interval of the substrates 2 to the outer frames 2a of two substrates 2 of the preceding and following sides in the feeding direction.

As shown in Fig.3F, the base film 8 is peeled after joining the photosensitive resin layer 9 to the substrate 2. In this way, only the photosensitive resin layer 9 remains on the substrate

2 and the state shown in Fig. 1 is obtained. Incidentally, the base film 8 may be peeled in a web state (hereinafter referred

to as continuous type) , and may be peeled after being cut into a sheet shape corresponding to each substrate (hereinafter referred to as sheet type) .

Fig. 4 is a schematic illustration showing a structure of the laminating apparatus according to the present invention. The laminating apparatus 20 joins the substrate 2 and the film 3 while continuously carrying them. The laminating apparatus 20 comprises a film supplying zone 21 for supplying the film 3, a joining zone 22 for joining the substrate 2 and the film 3, a substrate heating zone 23 for heating and feeding the substrate 2, a substrate cooling zone 24 for cooling the substrate 2 after completion of joining, and a base peeling zone 25 for peeling the base film 8 from the film 3.

In the laminating apparatus 20, a first clean room 29a and a second clean room 29b are partitioned by a partition wall 28. The first clean room 29a contains the film supplying zone 21. The second clean room 29b contains the joining zone 22, the substrate heating zone 23, the substrate cooling zone 24 and the base peeling zone 25. The first and second clean rooms 29a and 29b are connected via a through hole 28a formed in the partition wall 28.

The film supplying zone 21 comprises a film advancing mechanism 33, a processing mechanism 34, a label attaching mechanism 35 and a peeling mechanism 36. The film advancing mechanism 33 contains the film roll 6, in which the film 3 is wound in the roll form, and advances the film 3 from this film roll 6. The processing mechanism 34 performs the half-cut process for the protective film 10 of the advanced film 3. The label attaching mechanism 35 sticks the attachment label 13 on the protective film 10. The peeling mechanism 36 peels the protective film 10 from the film 3 at predetermined intervals.

The peeling mechanism 36 is composed of a suction drum 39 for working as a tension roller, a take-up roll 40 for taking up

the protective film 10 peeled from the film 3, and a plurality of guide rollers 41 for guiding the protective film 10 between the suction drum 39 and the take-up roll 40.

Fig. 5 shows an adjacent structure of the suction drum 39. The suction drum 39 is connected to an air pump (adsorption member) , which is not shown, to attract the film 3 by suction holes formed in a drum surface. The suction drum 39 is rotated by a motor 42 in a direction opposite to the film-carrying direction. Thus, the suction drum 39 works as the tension roller for applying constant load to the transport of the film 3 so that tension of the film 3 is stabilized between the suction drum 39 and the joining zone 22. Further, between the motor 42 and the suction drum 39, a powder clutch 43 is disposed for the purpose of regulating torque to be transmitted from motor 42 to the suction drum 39. The joining zone 22 is provided with a tension measuring portion 46 for measuring the tension of the film 3, a passage 47 into which the substrate 2 and the film 3 are fed, and a joining mechanism 48 disposed at the passage 47. The photosensitive resin layer 9 exposed by peeling the protective film 10 is joined to the substrate 2 by the joining mechanism 48. A route changing mechanism 49 , a preheater 50 and a detection camera 51 are disposed at an upstream side of the joining mechanism 48. When the film is stopped and when preparation is conducted, the route changing mechanism 49 changes a transport route of the film 3 to be sent into the joining mechanism 48. The preheater 50 preheats the film 3 up to a predetermined temperature. The detection camera 51 detects the half-cut portion of the film 3.

The tension measuring portion 46 is composed of a measurement roller 54 and a tension meter 55. The measurement roller 54 is rotated in association with the film 3 put thereon. The tension meter 55 measures the tension of the film 3 on the basis of pressure of the film 3 applied to the measurement roller

54. The measurement roller 54 and the tension meter 55 are held by an actuator 56 comprising an air cylinder, and are moved in a direction perpendicular to the transport direction of the film 3. When the route changing mechanism 49 has changed the transport route of the film 3, the actuator 56 moves the tension measuring portion 46 to keep a length of the transport route of the film 3 constant.

The powder clutch 43 and the tension meter 55 are connected to a tension controller 59, which comprises a memory 60, a torque calculator 61 and a drive-signal producer 62 to control the tension of the film 3 by controlling the powder clutch 43.

The memory 60 stores preset reference tension. The torque calculator 61 compares the measured tension, which is inputted from the tension meter 55, with the reference tension to calculate the torque of the suction drum 39 necessary for equalizing the measured tension to the reference tension. The drive-signal producer 62 produces a control signal of the powder clutch 43 on the basis of the torque calculated by the torque calculator 61 to control the torque to be transmitted from the motor 42 to the suction drum 39. In virtue of the tension controller 59, the tension of the film 3 is kept constant between the suction drum 39 and the joining mechanism 48.

Fig. 6A is a schematic illustration showing a structure of the passage 47. The joining mechanism 48 comprises laminating rollers 65a and 65b vertically arranged and heated up to a predetermined temperature. The respective laminating rollers 65a and 65b are composed of a columnar core, which is made of a metal and so forth, and a resilient material of silicon rubber and so forth coating the periphery of the core. Backup rollers 66a and 66b respectively come into contact with the peripheries of the laminating rollers 65a and 65b to keep pressurization of these laminating rollers constant. The laminating roller 65a is

rotated by a motor 67 to join the photosensitive resin layer 9 to the substrate 2 while interposing and carrying the film 3 and the substrate 2 with the laminating roller 65b.

The laminating roller 65b and the backup roller 66b disposed under the passage 47 are vertically movable. The backup roller 66b is vertically moved by an actuator 70 comprising a cylinder device, a solenoid and so forth. The laminating roller 65b is moved in association with the vertical movement of the backup roller 66b and is pressed against the laminating roller 65a. Incidentally, the backup roller 66b is vertically moved by a roller clamper 71 as well via the actuator 70. The roller clamper 71 performs the vertical movement by a motor and a cam mechanism, for example, to regulate the pressurization of the substrate 2 and the film 3. At the downstream side of the joining mechanism 48 , upstream film carrying rollers 75a, 75b and downstream film carrying rollers 76a, 76b are disposed to carry only the film 3 at the start-up time of the laminating apparatus 20. Moreover, upstream substrate carrying rollers 77a, 77b and downstream substrate carrying rollers 78a, 78b are disposed to simultaneously carry the substrate 2 and the film 3 at the joining time thereof. Further, auxiliary rollers 79 rotating in association with the substrate 2 placed thereon are disposed to assist the movement of the substrate 2. The upstream film carrying roller 75a, the downstream film carrying roller 76a, the upstream substrate carrying roller 77a and the downstream substrate carrying roller 78a are rotated by the motor 67 used for driving the laminating roller, and the other rollers are rotated in association with the movement of the substrate 2 and the film 3. The rollers 75b, 77a, 77b, 76b, 78a and 79 are vertically moved by actuators 82 to 87 respectively. When only the film 3 is carried, the upstream film carrying roller 75b and the

downstream film carrying roller 76b are moved to carry positions where these rollers come into contact with the photosensitive resin layer 9 of the film 3. Further, the upstream substrate carrying rollers 77a and 77b, the downstream substrate carrying roller 78a and the auxiliary rollers 79 are moved to evacuation positions where these rollers are separated from the film 3. Thus , the photosensitive resin layer 9 is prevented from adhering to the substrate carrying rollers and the auxiliary rollers 79. Meanwhile, as shown in Fig. 6B, when the substrate 2 and the film 3 are joined and carried, the upstream substrate carrying rollers 77a and 77b, the downstream substrate carrying roller 78a and the auxiliary rollers 79 are moved to carry positions where these rollers come into contact with the substrate 2 and the base film 8 of the film 3. At this time, the upstream film carrying roller 75b and the downstream film carrying roller 76b are moved to evacuation positions where these rollers are separated from the substrate 2. Thus, the photosensitive resin layer 9 having adhered to the film carrying rollers at the carry time of the film 3 is prevented from soiling the substrate 2. Fig. 7A is a timing chart showing a carry speed of the substrate 2 and the film 3 carried by the respective substrate carrying rollers 77a, 77b, 78a and 78b. Carrying the substrate 2 and the film 3 includes a film-carrying period during which only the film 3 is carried, and a joining period during which the substrate 2 fed into the joining mechanism 48 is joined with the film 3. These periods are repeated in order and the film 3 is sequentially joined to the plural substrates 2. Changing the carry speed is performed by adjusting a rotation speed of the motor 67, for example. The carry speed adopted in the joining period is defined as joining speed, which is suitable for joining the substrate 2 and the film 3. Meanwhile, the carry speed adopted in the

film-carrying period is defined as film-carrying speed, which is set so as to be slower than the joining speed for the purpose of improving accuracy of the joining position of the film 3 relative to the substrate 2. Consequently, an acceleration period for accelerating the carry speed occurs when the film-carrying period is changed to the joining period, and a deceleration period for decelerating the carry speed occurs when the joining period is changed to the film-carrying period.

Since the film 3 is strained in the joining zone 22 during the acceleration period, the upstream film tension increases. By contrast, since the carry speed of the film 3 decelerates in the joining zone 22 during the deceleration period, the upstream film tension decreases. In a conventional laminating apparatus, laminate quality sometimes deteriorates due to tension fluctuating during the acceleration period and the deceleration period, and feeding the next substrate 2 into the joining mechanism 42 is sometimes disturbed by a flap of the film 3. In the laminating apparatus of present invention, however, fluctuation of the tension is detected during the acceleration period and the deceleration period to control the powder clutch 43, and the torque to be transmitted from the motor 42 to the suction drum 39 is regulated so that the tension of the film 3 is kept constant .

Reference numeral 90 denotes an end-portion cutting mechanism for cutting an anterior end of the film 3 at a time of commencement of operation, and reference numeral 91 denotes a middle-portion cutting mechanism for cutting the film 3 between the substrates 2 when a trouble has occurred in the apparatus. Further, reference numeral 92 denotes an auxiliary roller for guiding the film 3 at a time when the film 3 cut by the end-portion cutting mechanism 90 is discarded from the passage 47.

The route changing mechanism 49 is composed of a contact

prevention roller 95 on which the film 3 is put, and an actuator 96 for moving the contact prevention roller 95. As to the actuator 96 , an air cylinder or the like is used, for instance, to vertically move the contact prevention roller 95. As shown in Fig. 6A, the actuator 96 moves the contact prevention roller 95 downward to prevent the film 3 from coming into contact with the laminating roller 65a and from being heated thereby when only the film 3 is fed into the passage 47, concretely when the film is stopped and when preparation operation is performed. Meanwhile, as shown in Fig. 6B, the actuator 96 moves the contact prevention roller 95 upward to increase a winding angle relative to the laminating roller 65a when the substrate 2 and the film 3 are joined.

Upon changing the transport route of the film 3 by the route changing mechanism 49, a length of the transport route of the film 3 is changed between the suction drum 39 and the joining mechanism 48. Further, as the length of the transport route changes, the tension of the film 3 also changes. In this regard, in the present invention, the actuator 56 is operated in association with the operation of the actuator 96 of the route changing mechanism 49 to keep the length of the transport route of the film 3 constant.

Concretely, the length of the transport route elongates when the contact prevention roller 95 is moved downward. At this time, the actuator 56 moves the tension measuring portion 46 in the right direction in Fig. 5 such as shown by a two-dot chain line of this drawing. In contrast, the length of the transport route shortens when the contact prevention roller 95 is moved upward. At this time, the actuator 56 moves the tension measuring portion 46 in the left direction in Fig. 5 such as shown by a solid line. Incidentally, when the tension measuring portion 46 is moved by the actuator 56 to keep the length of the transport route constant, the tension of the film 3 fluctuates by a little due

to a change of a winding angle of the film 3 relative to the suction drum 39. However, this fluctuation of the tension is also measured by the tension measuring portion 46 and is controlled by the tension controller 59 so that the tension of the film 3 is kept constant.

In the substrate heating zone 23, the substrate 2 contained in a substrate stocker 100 is taken out by a robot 101 and is supplied to a substrate conveying mechanism 102. The substrate 2 heated in the substrate conveying mechanism 102 is fed into the joining zone 22. In the cooling zone 24, the substrate 2 to which the film 3 is joined in the joining zone 22 is cooled by a cooling mechanism 103 and is forwarded to the base peeling zone 25 , wherein the base film 8 is peeled from the film 3 by a base peeling mechanism 104 to obtain the substrate 2 to which only the photosensitive resin layer 9 adheres. Further, a joining position of the photosensitive resin layer 9 is measured by a measuring unit 105, and then the substrate 2 is loaded into a processed-substrate stocker 107 by a robot 106.

The laminating apparatus 20 is totally controlled via a laminate process controller 110. For example, a substrate heating controller 111, a laminate controller 112 and a base peeling controller 113 are provided for the respective function parts of the laminating apparatus 20 and are connected via a process network. The laminate process controller 110 is connected to a factory network to perform production information processing of operation management and production management based on instruction information (condition setting and production information) sent from a factory CPU not shown.

The substrate heating controller 111 controls the substrate heating zone 23, and the base peeling controller 113 controls the base peeling zone 25. The laminate controller 112 controls the film supplying zone 21, the joining zone 22 and the substrate

cooling zone 24. At the same time, the laminate controller 112 controls the respective function parts as a master of the entire process. Further, the laminate controller 112 vertically moves the respective rollers by controlling the actuators 82 to 87, and keeps the tension of the film 3 constant by controlling the tension controller 59. Furthermore, the laminate roller 112 keeps the length of the transport route of the film 3 constant by controlling the actuators 56 and 96.

Next, an operation of the above embodiment is described below with reference to a flowchart shown in Fig .8. Upon starting the laminating apparatus 20, the laminate controller 112 forwards the film 3 to the film supplying zone 21 by the film advancing mechanism 33. For the forwarded film 3, the half-cut process is performed by the processing mechanism 34 and the attachment labels 13 are attached to the protective film 10 by the label attaching mechanism 35. Successively, the protective film 10 is peeled from the film 3 by the peeling mechanism 36, and then the film from which the protective film is peeled is fed into the joining zone 22. In the joining zone 22, the laminate controller 112 controls the actuators 82 through 87 to move the upstream film carrying roller 75b and the downstream film carrying roller 76b to the carry positions where these rollers come into contact with the photosensitive resin layer 9 of the film 3, such as shown in Fig. 6A. At this time, the laminate controller 112 moves the upstream substrate carrying rollers 77a and 77b, the downstream substrate carrying roller 78a and the auxiliary rollers 79 to the evacuation positions where these rollers are separated from the film 3. The film 3 is carried by the upstream film carrying rollers 75a, 75b and the downstream film carrying rollers 76a, 76b. The anterior end of the film 3 is sent to the outside of the passage 47 by the auxiliary roller 92 and is discarded after being cut by the

end-portion cutting mechanism 90.

While the film 3 is carried such as described above, the suction drum 39 disposed in the film supplying zone 21 is rotated by the motor 42 in the reverse direction of the film carrying direction to apply the tension to the film 3 between the suction drum 39 and the joining mechanism 48. This tension of the film 3 is measured by the tension meter 55 of the tension measuring portion 46 and is inputted into the tension controller 59.

In the torque calculator 61 of the tension controller 59, the measured tension inputted from the tension meter 55 is compared with the reference tension read from the memory 60 to calculate the torque of the suction drum 39 necessary for equalizing the measured tension with the reference tension. The torque calculated by the torque calculator 61 is inputted into the drive-signal producer 62 to produce the control signal of the powder clutch 43 necessary for obtaining the calculated torque. The powder clutch 43 is actuated on the basis of the produced control signal to regulate the torque to be transmitted from the motor 42 to the suction drum 39. In virtue of this, the tension of the film 3 is kept constant between the suction drum 39 and the joining mechanism 48.

After completing the preparation of the film 3, the substrate 2 is fed from the substrate heating zone 23 into the joining zone 22. The joining mechanism 48 pinches and presses the substrate 2 and the film 3 to join them. The laminate controller 112 controls the actuators 82 through 87 to move the upstream film carrying roller 75b and the downstream film carrying roller 76b to the evacuation positions where these rollers are separated from the substrate 2, such as shown in Fig. 6B. At this time, the laminate controller 112 moves the upstream substrate carrying rollers 77a and 77b, the downstream substrate carrying roller 78a and the auxiliary rollers 79 to the carry positions

where these rollers come into contact with the substrate 2 and the film 3 to carry them.

As shown by the two-dot chain line in Fig. 5, the contact prevention roller 95 is moved downward so as to separate the film 3 from the laminating roller 65a when only the film 3 is carried. When the substrate 2 has been fed into the joining zone 22 to commence joining the film 3 thereto, the contact prevention roller 95 is moved upward and the transport route is changed so as to increase the winding angle of the film 3 relative to the laminating roller 65a. Since the actuator 56 moves the tension measuring portion 46 in association with the movement of the contact prevention roller 95, the length of the transport route is prevented from changing between the suction drum 39 and the joining mechanism 48 so that the tension is also prevented from changing due to the length change of the transport route.

Incidentally, since the tension measuring portion 46 is moved by the actuator 56, the winding angle of the film 3 changes relative to the suction drum 39. Thus, the tension of the film 3 fluctuates by a little. However, this tension fluctuation is also controlled by the tension controller 59 so that the tension of the film 3 is kept constant.

Further, although the tension of the film 3 fluctuates during the acceleration period changing from the film-carrying period to the joining period and during the deceleration period changing from the joining period to the film-carrying period, this tension fluctuation is also controlled by the tension controller 59 so that the tension of the film 3 is kept constant.

In the above embodiment, the tension fluctuating in the acceleration period and the deceleration period is detected by the tension measuring portion 46, and the powder clutch 43 is controlled on the basis of the detection result of the tension measuring portion 46. However, since the occurrence timing of

the respective acceleration and deceleration periods is identified in advance in accordance with the feeding of the substrate 2 to be performed relative to the joining mechanism 48, and since acceleration and deceleration patterns thereof are constant, it is possible to compensate the acceleration and the deceleration with great accuracy by controlling the tension in synchronism with the acceleration period and the deceleration period.

For example, as shown in Fig. 9, PLC (Programmable Logic Controller) 120 is connected to the tension controller 59. Torque instruction is directly inputted from the PLC 120 to the drive-signal producer 62 of the tension controller 59 during the acceleration period and the deceleration period shown in Fig. 7A. As to the torque instruction, it is possible to prevent the film tension from increasing in the acceleration period by decreasing the torque to be transmitted from the motor 42 to the suction drum 39 in the acceleration period such as shown in Fig. 7B. In contrast, by increasing the transmission torque in the deceleration period, it is possible to prevent the film tension from decreasing.

In a case that the drive signal of the powder clutch 43 is produced in the drive-signal producer 62 on the basis of the torque inputted from the torque calculator 61 and the torque inputted from the PLC 120, it is possible to regulate other tension fluctuation as well, which is caused due to factors excluding the acceleration period and the deceleration period. In this case, the tension may be controlled with greater accuracy.

In the above embodiment, the powder clutch is used as a torque regulator. However, it is possible to use other clutches and drive transmitters of non-clutch. Moreover, the above embodiment relates to the continuous type in which the base film 8 is peeled without cutting the film 3. The present invention,

however, may be adopted to the sheet type in which the base film 8 is peeled after cutting the film 3 every substrate 2. Further, in the above-described laminating apparatus , one strip of the film 3 is joined to the substrates 2. The present invention, however, may be adopted to another laminating apparatus in which plural film strips are joined to the substrates in parallel . Furthermore , in the foregoing laminating apparatus, the photosensitive resin layer is formed on the glass substrate of the color filter. The present invention, however, may be adopted to laminating apparatuses used for other products.

In the present invention, the film comprising the adhesive photosensitive resin layer is joined to the substrate. The present invention, however, may be adopted to joining of a substrate and a film having a nonadhesive joining surface.

Industrial Applicability

The present invention is preferably applied to a laminating apparatus in which tension of a film is kept constant.