JP2013050475A - Continuous manufacturing method of product panel and detection system and method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous manufacturing method of a product panel which allows the product panel to be continuously manufactured with high adhesion precision.SOLUTION: The method includes: putting a film front edge of a sheet-shaped polarizing film close to a junction with a rectangular panel to detect the film front edge; adjusting positions of the sheet-shaped polarizing film and the rectangular panel on the basis of positional information on the detected film front edge; and pasting the sheet-shaped polarizing film and the rectangular panel together. In order to detect the film front edge, light having an optical axis that makes an acute angle with respect to the feed direction of the film is emitted toward the film front edge from the upstream side of the feed direction of the sheet-shaped polarizing film. An image is acquired by imaging the region illuminated by the light, and the film front edge is identified on the basis of the difference in brightness between the image of the film front edge and the image of portions other than the film front edge.

Description

  The present invention relates to a continuous manufacturing method of a product panel in which sheet-like polarizing films are sequentially bonded to a rectangular panel that is continuously sent to a bonding position. In particular, the present invention relates to a continuous manufacturing method of a product panel that facilitates detection of a front end portion of a sheet-like polarizing film that serves as a reference for alignment when a sheet-like polarizing film and a rectangular panel are bonded together.

  Conventionally, in the manufacture of a product panel such as a liquid crystal display panel, a sheet-like polarizing film cut out in advance from a continuous web-like polarizing film outside the manufacturing process of the product panel is brought into the manufacturing process of the product panel. It is bonded to a rectangular panel that was brought separately into the manufacturing process.

  For such a manufacturing method, among the plurality of sheet-like polarizing films laminated on the continuous web-like separator film via the adhesive layer, only normal sheets having no defects are sequentially added together with the adhesive layer from the continuous web-like separator film. An apparatus and a method for continuously manufacturing a product panel by peeling and bonding to a rectangular panel with an adhesive layer have been proposed. Such a continuous manufacturing apparatus and method for a product panel is described in, for example, Patent Document 1 (Japanese Patent No. 4377964).

  In the continuous production of the product panel described in Patent Document 1, a roll of a laminate in which a continuous web-like separator film and a continuous web-like polarizing film are laminated is used. The continuous web-like polarizing film fed out from this roll is placed on the continuous web-like separator film by inserting a horizontal score line at a position determined based on the result of a defect inspection performed in advance. A sheet-like polarizing film is formed. The score line may be put in advance in a roll of the laminate. The sheet-like polarizing film is conveyed to the vicinity of the bonding position with the rectangular panel by the continuous web-like separator film (in this way, the continuous web-like separator film has a function as a carrier for conveying the sheet-like polarizing film. (Hereinafter referred to as “continuous web carrier film”). In the present specification, the “bonding position” is a position where the bonding of the film front end of the sheet-like polarizing film and the panel front end of the rectangular panel is started. On the other hand, the rectangular panel is also transported to the vicinity of the bonding position. When the sheet-like polarizing film conveyed to the vicinity of the bonding position is a normal (that is, no defect) sheet-like polarizing film, the position of the rectangular panel is corrected based on the position information. A normal sheet-like polarizing film is peeled from the continuous web-like carrier film by a peeling means. The sheet-shaped polarizing film is conveyed to the bonding position while being peeled off, and is bonded to the rectangular panel using a bonding means such as a bonding roller. Correcting the position of the rectangular panel based on information on the position of the normal sheet-shaped polarizing film is referred to as “positioning” between the sheet-shaped polarizing film and the rectangular panel.

  The alignment between the normal sheet-shaped polarizing film and the rectangular panel is generally performed as follows. First, when the film front end portion of the sheet-like polarizing film to be bonded (that is, the portion where the horizontal cut line is inserted) reaches the peeling means, it is substantially perpendicular to the surface of the sheet-like polarizing film. Light is emitted from a light source arranged in any direction to the front end of the film, and the irradiated portion is imaged by an image acquisition means such as a CCD camera. The film front end may be irradiated with room light or natural light. Next, the front edge of the film is detected in the captured image, and its position is calculated. Based on the detected position information of the front end, the position of the rectangular panel in the transport direction and the transverse direction, and the angle between the center line or the lateral end and the transport direction are corrected.

  On the other hand, in recent years, product panels such as liquid crystal display panels have been reduced in size, thickness, and weight, and accordingly, the periphery of the display area has been narrowed, that is, the frame has been narrowed. In order to realize a narrow frame, higher bonding accuracy between the rectangular panel and the polarizing film is required.

  However, the conventional continuous manufacturing apparatus and method for product panels has a drawback that it is difficult to obtain high bonding accuracy, which is expected to increase in demand in the future. In the conventional continuous manufacturing apparatus and method for product panels, the front end of the film is detected when the film front end of the sheet-like polarizing film is present on the peeling means, and the sheet-like polarizing film is detected by the peeling means. The film front end is conveyed to the bonding position while being gradually peeled from the carrier film. On the other hand, the rectangular panel is conveyed to the bonding position after the position is corrected based on the detected position information of the front end of the film. In the course of this transport, the transport amount of the sheet-like polarizing film varies due to the force exerted on the film at the time of peeling or the fluctuation in tension during transport. Therefore, when the film front end and the panel front end reach the bonding position, the position of the sheet-like polarizing film varies from the original position obtained by alignment, and as a result, the sheet-like polarizing film and the rectangular shape are rectangular. Misalignment with the panel will occur. At present, it is difficult to accurately adjust the transport amount of the sheet-like polarizing film. Therefore, the conventional continuous manufacturing apparatus and method for product panels provide a high level of bonding accuracy required for narrowing the frame. It's hard to be done.

  For example, Patent Document 2 (Japanese Patent Application Laid-Open No. 2007-212939) describes a method for detecting a positional deviation in bonding between a polarizing film and a substrate. However, the technique described in Patent Document 2 is for detecting a positional deviation between the film and the substrate after the polarizing film is bonded onto the substrate. Since the polarizing film has only a thickness of about 200 to 300 μm, when the light is radiated to detect the end of the film, the technique described in Patent Document 2 is independent of the positional relationship between the polarizing film and the substrate and the light source. Inevitably, light is radiated to the end portions of the substrate, the circuit pattern, and the like, and the scattered light from these end portions is detected as disturbance light. Therefore, it is expected that it is difficult to detect the film edge due to scattered light from a portion other than the film edge. Thus, the technique described in Patent Document 2 is not applicable to a technique for continuously manufacturing product panels.

Japanese Patent No. 4377964 JP 2007-212939 A Japanese Patent No. 4644755

  As described above, in the conventional continuous manufacturing, in order to obtain information on the position of the film front end portion of the sheet-like polarizing film that serves as a reference for correcting the position of the rectangular panel, the film front end portion is detected by the film front end portion. This was done when present on the stripping means. This is because the contrast difference between the film front end and the background of the film front end, that is, the background of the peeling means increases in the captured image due to the reflected light from the peeling means, so that the film front end is easily detected. .

  However, in order to achieve high bonding accuracy, the alignment between the sheet-like polarizing film and the rectangular panel is as possible as the film front end of the sheet-like polarizing film is between the bonding position or the peeling means and the bonding position. It is preferable to be performed when the position is close to the bonding position. However, in such a case, since there is no other member in the background of the film front end in the captured image, there is no contrast difference between the film front end and the background, and it is extremely difficult to detect the film front end. There is a problem. If the contrast difference between the film front edge and the background disappears, the film front edge may not be detected. In addition, even if the front edge of the film can be detected, it may take a long time to detect. In this case, the number of product panels manufactured per unit time is reduced, and the apparatus for continuously manufacturing product panels And the superiority of the method is reduced.

  An object of the present invention is to provide a continuous manufacturing method of a product panel capable of continuously manufacturing a product panel having a high bonding accuracy, and to detect an end portion of a film suitable for use in this method. It is to provide a detection system and a detection method.

  In the present invention, even when the front end of the film is detected after a part of the sheet-like polarizing film including the front end of the film has been peeled off from the carrier film, the detection is facilitated by illuminating the front end of the film. It was made based on.

  In the first aspect, the present invention sequentially peels a plurality of sheet-shaped polarizing films laminated on one surface of a continuous web-like carrier film through an adhesive layer from the continuous web-like carrier film together with the adhesive layer. Provided is a method for continuously manufacturing a product panel by bonding to a rectangular panel with an adhesive layer at a joint position. The method comprises steps of peeling a part of the sheet-like polarizing film from the continuous web-like carrier film, bringing the film front end of the sheet-like polarizing film closer to the bonding position with the rectangular panel, and detecting the film front end. And a step of aligning the sheet-like polarizing film and the rectangular panel based on the detected position information of the front end of the film, and a step of bonding the sheet-like polarizing film and the rectangular panel. The step of detecting the front edge of the film forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side in the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film. A step of irradiating light having an optical axis toward the front end of the film; a step of capturing an image of the light-irradiated region of the sheet-like polarizing film; and an image of the front end of the film appearing in the image; Identifying the front edge of the film based on the difference in brightness from the image of the portion other than the front edge of the film.

  Even if the rectangular panel is conveyed to the bonding position after the step of aligning the sheet-shaped polarizing film and the rectangular panel, the rectangular panel is conveyed to the bonding position during the step of aligning the sheet-shaped polarizing film and the rectangular panel. May be.

  In this method, in the step of irradiating light toward the film front end, light having an optical axis that forms an angle smaller than 45 ° with respect to the feeding direction of the sheet-like polarizing film is irradiated toward the film front end. Is preferred. Moreover, in this method, it is preferable to image the area | region where light was irradiated from the surface side opposite to the adhesion layer of a sheet-like polarizing film.

  The step of identifying the film front end includes scanning the image in a direction corresponding to the upstream side from the direction corresponding to the downstream side in the feeding direction of the sheet-like polarizing film, and identifying the bright portion in the image as the film front end. It is preferable.

  In the second aspect, the present invention is a film of a sheet-like polarizing film peeled before bonding, which is used in an apparatus for continuously producing a product panel by bonding to a rectangular panel with an adhesive layer at a bonding position. A detection system for detecting a front end is provided. This system is a light having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side of the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film. At least one light source, at least one image acquisition means for acquiring an image by imaging a region irradiated with light of the sheet-like polarizing film, and a film front end that appears in the image Film front end part identifying means for identifying the film front end part based on the difference in brightness between the image of the image and the image of the part other than the front end part.

  In this system, it is preferable that the optical axis and the feeding direction of the sheet-like polarizing film form an angle smaller than 45 °. Moreover, in this system, it is preferable that an image acquisition means images the area | region where light was irradiated from the surface side opposite to the adhesion layer of a sheet-like polarizing film. The film front end identifying means preferably scans the image in a direction corresponding to the upstream side from the direction corresponding to the downstream side in the feeding direction of the sheet-like polarizing film, and identifies the bright part in the image as the film front end.

  In a third aspect, the present invention is a film of a sheet-like polarizing film peeled off before being used in an apparatus for continuously producing a product panel by being bonded to a rectangular panel by an adhesive layer at the bonding position. A detection method for detecting a front end is provided. In this method, light having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side in the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film. , Toward the front end of the film, to capture an image of the area of the sheet-like polarizing film irradiated with light, to obtain an image, and an image of the front end of the film appearing in the image and a portion other than the front end Identifying the front edge of the film based on the difference in brightness from the image of the image.

  In this method, in the step of irradiating light toward the film front end, light having an optical axis that forms an angle smaller than 45 ° with respect to the feeding direction of the sheet-like polarizing film is irradiated toward the film front end. Is preferred. Moreover, in this method, it is preferable to image the area | region where light was irradiated from the side opposite to the adhesion layer of a sheet-like polarizing film. The film front end identifying step includes scanning the image in a direction corresponding to the upstream side from the direction corresponding to the downstream side in the feeding direction of the sheet-like polarizing film, and identifying the bright part in the image as the film front end. preferable.

  According to the present invention, a part of the sheet-like polarizing film is peeled off from the carrier film by the peeling means, and even when the film front end is at the bonding position or the position between the peeling means and the bonding position, Detection of the film front end becomes easy. Therefore, the time required for detecting the film front end can be shortened, and the number of product panels manufactured per unit time can be increased. In addition, the detection of the front end of the film is performed at a bonding position or a position closer to the bonding position, so that it is not necessary or necessary to move the sheet-shaped polarizing film after alignment between the sheet-shaped polarizing film and the rectangular panel. Since the distance is shortened, the bonding accuracy can be further improved.

It is the schematic of the product panel continuous manufacturing apparatus concerning one Embodiment of this invention. It is a flowchart which shows the process for the product panel continuous manufacture concerning one Embodiment of this invention. It is a figure which shows the state by which the sheet-like polarizing film is formed on the continuous web-like carrier film concerning one Embodiment of this invention. It is the schematic which shows the conventional structure for detecting the film front-end part on a peeling means. It is a photograph which shows an example of the image acquired using the structure shown by FIG. It is a photograph which shows an example of the image at the time of trying to detect a film front-end part in the place near a bonding position rather than a peeling means using the structure shown by FIG. It is the schematic which shows the structure for detecting the film front-end part in the place near the bonding position from the peeling means concerning one Embodiment of this invention. It is a photograph which shows the one part image of the sheet-like polarizing film containing a film front end part when the angle which the optical axis of a light source and the feed direction of a sheet-like polarizing film make is 20 degrees. It is a photograph which shows the image of a part of sheet-like polarizing film including a film front end part when the angle which the optical axis of a light source and the feed direction of a sheet-like polarizing film make is 75 degrees. It is a photograph which shows the one part image of the sheet-like polarizing film containing the film front end part when the angle which the optical axis of a light source and the feed direction of a sheet-like polarizing film make is 90 degrees. It is a flowchart which shows the process from the detection of a film front-end part to position of a film front-end part to a bonding reference | standard position concerning one Embodiment of this invention. It is a figure which shows the improvement effect of the bonding precision at the time of detecting the position of a film front-end part using the detection method of the film front-end part concerning one Embodiment of this invention.

<Outline of continuous production apparatus and method for product panels according to the present invention>
Hereinafter, the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an apparatus for realizing a continuous manufacturing method for product panels according to the present invention, and FIG. 2 is a process flow diagram of the continuous manufacturing method according to the present invention. The continuous production apparatus 1 shown in FIG. 1 is a bonding apparatus that bonds the sheet-shaped polarizing film 10 shown in FIG. 3 to the bonding station and the sheet-shaped polarizing film 10 and the rectangular panel W. 200, the rectangular panel conveyance apparatus 300 which conveys the rectangular panel W to a bonding position, and the control apparatus 400 which controls the operation | movement of the film conveyance apparatus 100, the bonding apparatus 200, and the rectangular panel conveyance apparatus 300 whole. The sheet-like polarizing film 10 conveyed to the bonding station is bonded to the rectangular panel W at the bonding position, and the manufactured product panel is unloaded from the continuous manufacturing apparatus 1 by the product panel transfer device 350.

  The outline of the apparatus and operation of the continuous production apparatus 1 will be described with reference to FIGS. 1 and 2. In addition, about this apparatus, it describes in detail in patent document 1 which concerns on the prior application of this applicant about details other than the structure and method for detecting the film front-end part of the sheet-like polarizing film 10 in a bonding station. In the continuous manufacturing method according to the present application, the same configuration and method as those described in Patent Document 1 can be adopted. In the film transport apparatus 100 of the continuous manufacturing apparatus 1, a roll of a laminate in which a continuous web-shaped polarizing film is laminated on a continuous web-shaped carrier film 14 via an adhesive layer 12 is mounted on the support apparatus 110. The laminated body is fed out from the roll of the laminated body attached to the. For example, coded cutting position information is given to the fed stack, and the cutting position information is read by the reading device 120. The cutting position is determined in advance based on the result of defect inspection performed at the time of manufacturing the roll of the laminate, and the determined cutting position is preferably coded as cutting position information and given to the laminate. Next, the laminated body is conveyed to a cutting station, and the cutting line 16 is put into the laminated body by the cutting device 150. As shown in FIG. 3, the cutting line 16 is transverse to the conveying direction of the laminate from the side opposite to the continuous web-shaped carrier film 14 based on the cutting position information read by the reading device 120. Be put in. The depth of the score line 16 is a depth that reaches the interface between the continuous web-like carrier film 14 and the adhesive layer 12.

  The state of the laminate after cutting is shown in FIG. The laminated body after cutting has a structure in which a plurality of sheet-like polarizing films 10 partitioned by the cut lines 16 are laminated on the continuous web-like carrier film 14 via the adhesive layer 12. The sheet-like polarizing film 10 is generally a protective film laminated on both sides of a polarizer. A surface protective film 13 having an adhesive surface may be laminated on the sheet-like polarizing film 10 as necessary.

  It is preferable that the position of the formed cutting line 16 is read by the cutting position confirmation device 160, and the deviation of the cutting position and the cutting angle is corrected based on the result. Note that when the film is cut and bonded, it is preferable that the speed of film conveyance is adjusted by a speed adjusting device 140 including an accumulator roller. As a result of the cut line 16 being inserted, a normal sheet-shaped polarizing film having no defects and a defective sheet-shaped polarizing film having defects are laminated on the continuous web-shaped carrier film 14 via the adhesive layer 12. It will be in the state. The sheet-like polarizing film 10 is conveyed toward the bonding station 200 by the continuous web-like carrier film 14. The defective sheet-like polarizing film is preferably discharged before reaching the bonding station or in the bonding station using a defective sheet discharge mechanism (not shown).

  As another form of the laminated body, a roll having a cut line 16 formed in advance may be used as the roll of the laminated body mounted on the continuous manufacturing apparatus 1. In this case, the continuous manufacturing apparatus 1 may have a structure in which the reading device 120 and the cutting station are removed from the apparatus shown in FIG. In the case of this form, the laminated body drawn out from the roll of the laminated body has a structure shown in FIG.

  The normal sheet-like polarizing film of the sheet-like polarizing film 10 is then bonded to the rectangular panel W that has been transferred to the bonding station by the rectangular panel transfer device 300 using the bonding device 200. The sheet-like polarizing film 10 conveyed to the laminating station together with the continuous web-like carrier film 14 has the traveling direction of only the continuous web-like carrier film 14 in the traveling direction of the continuous web-like carrier film 14 by the acutely formed front end portion of the peeling means 201. Is peeled from the continuous web-like carrier film 14 together with the adhesive layer 12 by reversing in a direction substantially opposite to the feeding direction (hereinafter referred to as “feeding direction”). The film front end portion 10a of the peeled sheet-like polarizing film 10 is either a bonding position between a pair of bonding rollers 202 spaced apart from each other by the bonding apparatus 200, or between the peeling means and the bonding position. It is conveyed to the position. As for the conveyed sheet-like polarizing film 10, the position of the film front-end part 10a is detected. When the detection is performed at any position between the peeling unit 201 and the bonding position, the film front end portion 10a is further conveyed to the bonding position after the detection.

  On the other hand, the rectangular panel W is conveyed to the bonding station by the rectangular panel conveying device 300, and in the process, the position is corrected based on the detected information on the position of the film front end portion 10a (that is, The sheet-like polarizing film and the rectangular panel are “aligned”). After alignment, the front end of the rectangular panel W is conveyed to the bonding position between the bonding rollers 202. The rectangular panel W may be conveyed to the bonding position at the time of alignment, and the front end may be arranged at the bonding position when the alignment is completed. Next, the laminating roller 202 is closed, and the sheet-shaped polarizing film 10 and the rectangular panel W are bonded together by moving forward between the closed laminating rollers 202 while the sheet-shaped polarizing film 10 and the rectangular panel W are bonded together. Is completed. The continuous web-like carrier film 14 from which the sheet-like polarizing film 10 has been peeled is taken up by a take-up device 170.

<Outline of alignment method>
The sheet-like polarizing film 10 and the rectangular panel W are aligned before bonding. The outline of the alignment method is as follows. The details of the alignment method between the sheet-like polarizing film 10 and the rectangular panel W are described in detail in Patent Document 3 according to the prior application of the applicant of the present application, and the patent is also applied to the continuous manufacturing method according to the present application. A method similar to the method described in Document 3 can be employed. First, a part of the sheet-like polarizing film 10 including the film front end portion 10 a is peeled off from the continuous web-like carrier film 14 by the peeling means 201. After peeling, when the film front end part 10a reaches any position between the bonding position or the peeling means 201 and the bonding position, light is irradiated from the light source 204 toward the film front end part 10a. The part of the sheet-like polarizing film 10 irradiated with light or a part thereof is imaged by an image acquisition means 203 such as a CCD camera. Considering that higher bonding accuracy is required for narrowing the product panel, detection of the film front end portion 10a of the sheet-like polarizing film 10 is performed by bonding the film front end portion 10a of the sheet-like polarizing film 10. More preferably, it is performed when the position is reached. Based on the captured image, the film front end portion 10a is detected, and the position of the detected film front end portion 10a is calculated. The image acquisition means 180 which images the side edge part of the sheet-like polarizing film 10 is provided at any position in front of the bonding station, and the film side edge part of the sheet-like polarizing film 10 is determined based on the captured image. It is also possible to detect and calculate the position of the film side end.

  In the image of the image acquisition means 203, a film reference position, that is, a film reference position for positioning the sheet-like polarizing film 10 and the rectangular panel W is determined in advance. The film reference position is for positioning the sheet-like polarizing film 10 when the sheet-like polarizing film 10 is disposed on a reference line that represents the direction in which the sheet-like polarizing film 10 should be originally conveyed. The sheet-like polarizing film 10 that has reached the detection position of the front end of the film is based on the calculated positions of the front end and the side end of the film, the amount of deviation of the angle from the film reference position, the feed direction from the film reference position, and The amount of displacement in the transverse direction is determined. Also for the rectangular panel W, the panel reference position (that is, the reference position of the panel for aligning the sheet-like polarizing film 10 and the rectangular panel W) based on the alignment mark provided on the rectangular panel W separately. The gap between them is calculated. The position of the rectangular panel W is corrected based on the obtained shift amount of the sheet-like polarizing film 10.

  After the position of the rectangular panel W is corrected, the sheet-like polarizing film 10 and the rectangular panel W are bonded together. In the case of the embodiment in which the detection of the film front end portion 10a is performed at any position between the peeling means 201 and the bonding position, the sheet-like polarizing film 10 is further conveyed to the bonding position, and the bonding reference The position is aligned with the reference position in the bonding position between the sheet-like polarizing film 10 and the rectangular panel W. The rectangular panel W is also conveyed to the bonding position and aligned with the bonding reference position. When the detection of the film front end portion 10a is performed at the bonding position, the rectangular panel W is conveyed to the bonding position based on the position, and is aligned with the bonding reference position. In this case, the film reference position and the bonding reference position are the same position. Next, the aligned sheet-like polarizing film 10 and the rectangular panel W are bonded together by the bonding roller 202.

  From this alignment method, it can be understood that it is extremely important to accurately detect the position of the front end of the film, which serves as the alignment reference, in order to improve alignment accuracy.

<Conventional film front end detection method and problems in improving bonding accuracy>
Here, the detection method of the film front-end part on the peeling means performed conventionally is demonstrated. FIG. 4 is a schematic diagram showing a configuration of a conventional configuration 600 for detecting the film front end portion 10a on the peeling means 201. As shown in FIG. In the conventional configuration 600, when the film front end portion 10a of the sheet-like polarizing film 10 on the continuous web-like carrier film 14 comes on the peeling means 201 (that is, the film front end portion 10a is peeled from the continuous web-like carrier film 14). Light) is irradiated from the light source L toward a predetermined region including the film front end portion 10a. The light may be natural light or room light. Moreover, light may be always irradiated. In the conventional configuration 600, the light source L is arranged in a direction substantially perpendicular to the film surface, and thus light is emitted from a direction substantially perpendicular to the film surface. The area irradiated with light is captured by an image acquisition unit 203 such as a CCD camera, and an image of the captured area is acquired. The acquired image is binarized based on the luminance in the image.

  FIG. 5 is a photograph showing an example of the pre-binarized image acquired in this way. In FIG. 5, the peeling means tip R portion is a sheet when the continuous web-like carrier film 14 passing through this portion along R is pulled in a direction generally opposite to the feeding direction by the winding device 170 (FIG. 1). It is a part which functions so that the polarizing film 10 and the adhesion layer 12 may peel from the continuous web-like carrier film 14. From FIG. 5, it can be seen that a part of the polarizing film 10 is present on the peeling means 201 before the peeling means tip R portion. In the image, since the sheet-like polarizing film 10 is black and the surface of the peeling means 201 appears white, the contrast difference between the sheet-like polarizing film 10 and the surface of the peeling means 201 is large. Therefore, when this image is binarized, the film front end portion of the sheet-like polarizing film 10 can be easily detected.

  However, when the film front end portion 10a is detected on the peeling means 201 in this way, the bonding accuracy between the sheet-like polarizing film 10 and the rectangular panel W is lowered. This is due to the following reason. That is, in the case of the configuration in which the film front end portion 10a is detected on the peeling means 201, the position of the detected front end portion 10a is calculated after the detection of the film front end portion 10a, and the rectangular panel W is based on the position information. The position of is corrected. Subsequently, the film front-end part 10a is peeled from the continuous web-shaped carrier film 14, and is conveyed to the bonding position, and the rectangular panel W is also conveyed to the bonding position in synchronization therewith. The distance from the front end portion of the peeling means 201 to the bonding position is usually about 10 mm to about 50 mm, but in the process in which the sheet-like polarizing film 10 is transported this distance, the force during peeling and the tension during transportation. The transport amount varies due to fluctuations and the like. Accordingly, when the film front end portion 10a and the panel front end portion Wa reach the bonding position, the position of the sheet-like polarizing film 10 is displaced from the position where the original bonding obtained by the alignment is to be started, As a result, sticking displacement between the sheet-like polarizing film 10 and the rectangular panel W occurs. At the present time, it is difficult to accurately adjust the variation in the transport amount. Therefore, it is difficult to obtain a high level of bonding accuracy required for narrowing the frame with the conventional continuous manufacturing apparatus and method for product panels.

  Therefore, in order to improve the bonding accuracy, when the film front end portion 10a is peeled off from the continuous web-like carrier film 14 by the peeling means 201, when reaching the bonding position or the position as close as possible to the bonding position, It is preferable that the film front end portion 10a is detected. However, in the conventional configuration, when the film front end portion 10a is between the peeling means 201 and the bonding position, as shown in FIG. 6, there is another member on the background of the sheet-like polarizing film 10 in the imaging region. Since it does not exist, the film front end portion 10a cannot be distinguished from the background, and there is a problem that it is extremely difficult to detect the film front end portion 10a.

<Configuration for Film Front End Detection and Detection Method According to the Present Invention>
In the present invention, it is possible to easily detect the film front end portion 10a of the sheet-like polarizing film 10 between the bonding position or the peeling means 201 and the bonding position by adopting the configuration 700 shown in FIG. it can. Fig.7 (a) is a perspective view which represents typically the positional relationship of each member in the structure 700 for implement | achieving the continuous manufacturing method and film front end part detection method which concern on this invention, FIG.7 (b) is shown. It is the schematic diagram which looked at the structure 700 from the horizontal direction with respect to the feed direction. FIG. 9 shows a processing flow from the detection of the film front end portion 10a until the film front end portion 10a is aligned with the bonding reference position.

  In the structure 700, after the sheet-like polarizing film 10 is peeled from the continuous web-like carrier film 14 by the peeling unit 201, the sheet-like polarizing film 10 is conveyed to a bonding position or any position between the peeling unit 201 and the bonding position. Therefore, the film front end portion 10a is detected. When the film front end portion 10a reaches the detection position, that is, the bonding position or any position between the peeling means 201 and the bonding position, light is irradiated from the light source 204 toward the film front end portion 10a. Whether the detection position of the film front end portion 10a is a bonding position or a position between the peeling means and the bonding position is continuous depending on the bonding accuracy required for the product panel. It is set in advance before the operation of the manufacturing apparatus 1 is started.

  As shown in FIG. 7B, the light source 204 is on the surface of the sheet-like polarizing film 10 opposite to the continuous web-like carrier film 14 from the bonding position with respect to the feeding direction of the sheet-like polarizing film 10. It arrange | positions in an upstream, More preferably, it arrange | positions upstream from the front-end part of the peeling means 201. FIG. Further, the angle θ between the optical axis of the light emitted from the light source 204 and the surface of the sheet-like polarizing film 10 (that is, the film feeding direction) is set to an acute angle. The angle θ is more preferably an angle smaller than 45 °.

  In the present invention, when light from a light source 204 having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film 10 is applied to the film front end portion 10a of the sheet-like polarizing film 10, light is emitted from the film front end portion 10a. The phenomenon of scattering is used. Since this scattered light is captured as strong light in the image photographed by the image acquisition means 203 as compared with other portions, the front end portion 10a can be easily detected. This scattered light is caused by light from the light source 204 being diffusely reflected at the film front end portion 10a due to burrs and roughness of the cut portion generated in the web-like polarizing film 10 when the cut line 16 is formed, and from the light source 204. The light that has entered the film travels toward the film front end portion 10a while being reflected, for example, at the interface between the protective film and the polarizer in the sheet-like polarizing film 10 that is a laminate of a plurality of films. This is considered to be caused by leakage from the front end portion 10a.

  The intensity of the scattered light increases as the angle θ between the optical axis of the light source 204 and the feeding direction decreases. The present inventors consider that this phenomenon is due to the following three reasons. For one thing, since the amount of light directly irradiated onto the sheet-like polarizing film 10 decreases as the angle θ decreases, the contrast between the film front end portion 10a shined by scattered light and other portions increases. is there. Next, as the angle θ decreases, the apparent size of burrs and roughness as seen from the light source 204 increases, so that light is more likely to be scattered. Finally, as the angle θ decreases, the amount of light entering the sheet-like polarizing film 10 and internally reflected in the sheet-like polarizing film 10 increases, and the amount of light leaking from the film front end portion 10a increases. .

  The main reasons for arranging the light source 204 not on the downstream side of the bonding position but on the upstream side are as follows. First, when the light source 204 is arranged on the downstream side of the bonding position, the irradiated light is reflected by the bonding roll 202, and due to the influence of this reflected light, the film front end portion 10a and other portions in the imaging region And the contrast of the front end 10a becomes difficult to detect. Further, the angle θ between the optical axis of the irradiated light and the film feeding direction is preferably as small as described above. However, since there is a conveyance path for the product panel on the downstream side of the bonding position, the angle θ Must be larger than the case where the light source 204 is disposed upstream of the bonding position. When the angle θ is increased, the angle between the line connecting the image acquisition unit 203 and the film front end portion 10a and the optical axis of the irradiation light from the light source 204 decreases, so that the angle from the film incident on the image acquisition unit 203 is reduced. The amount of reflected light increases, and as a result, the contrast of the film front end portion 10a in the imaging region further decreases. Second, by arranging the light source 204 on the upstream side of the bonding position, the scattered light from the film front end portion 10a is caused by leakage of reflected light from the film front end portion 10a inside the sheet-like polarizing film 10 as described above. Become stronger.

  8A to 8C are photographs obtained by experiments to show that the smaller the angle θ, the greater the contrast between the scattered light from the film front end captured in the imaging region and the surrounding portion. In these photographs, the distance between the film front end and the light source is 500 mm, and the angle between the surface of the sheet-like polarizing film and the optical axis of the light source is 20 ° (FIG. 8A), 75 ° (FIG. 8B), and 90 ° (FIG. 8C). ), 50 cd light is irradiated from the light source toward the film front end, and a part of the film including the film front end is photographed by a camera installed in a direction perpendicular to the film surface. From FIG. 8A to FIG. 8C, it can be seen that as the angle θ decreases, the brightness of the film front end increases and the contrast between the film front end and the surroundings increases. In the case of the angle of 20 ° shown in FIG. 8A, it can be seen that only the front end of the film is shining.

  The type of the light source 204 is not particularly limited as long as the image acquisition unit 203 can image the film front end portion 10a by the light irradiated to the film front end portion 10a of the sheet-like polarizing film 10, and the LED light source and the incandescent light bulb are not limited. Any light source such as a light source or an HID light source can be used. The number of the light sources 204 is not particularly limited, but it is preferable that at least two light sources 204 are arranged so that two corners of the film front end portion of the sheet-like polarizing film 10 can be irradiated.

  The image acquisition unit 203 is not particularly limited, and a general-purpose imaging device such as a CCD camera can be used. The image acquisition unit 203 is disposed on the side of the sheet-like polarizing film 10 opposite to the continuous web-like carrier film 14, and preferably, an area irradiated with light from a direction substantially perpendicular to the feeding direction. Take an image. The number of the image acquisition means 203 is not limited, but is preferably the same as the number of the light sources 204, and at least 2 so that two corners of the film front end portion of the sheet-like polarizing film 10 can be imaged. Preferably, two image acquisition means 203 are arranged.

  The image acquired by the image acquisition unit 203 is output to the film front end identification unit 205, and the image is analyzed. The film front end identifying means 205 is preferably provided in the information processing apparatus 401, but is not limited to this, and may be provided in one apparatus together with the image acquisition means 203, for example. The film front end identifying means 205 uses an image analysis method for converting the acquired image into a binarized image using only white and black, but the image analysis method is not limited to this, Any method can be used as long as the bright part and the dark part can be accurately identified. Binarization is performed by obtaining the brightness of each pixel in the image, and setting the pixel to white if the brightness is greater than a certain threshold, and black if the brightness is smaller. Therefore, in the present invention, the film front end portion 10a is expressed as white in the acquired image.

  In this invention, even if it is a case where detection of the film front-end part 10a is performed in the bonding position, or is performed between the peeling means 201 and the bonding position, the rectangular panel W is at least It is set so that it waits in a predetermined position until the detection of the film front end portion 10a is completed. From the viewpoint of improving the bonding accuracy, it is preferable that both the sheet-like polarizing film 10 and the rectangular panel W have a small number of conveyance stops until the bonding starts, and the conveyance distance from the alignment position to the bonding position is as short as possible. . Therefore, it is preferable that the rectangular panel W waits in the position where the front-end part is as close as possible to the bonding position. On the other hand, as the position of the front end portion of the rectangular panel W approaches the bonding position, the film front end portion 10a and the front end portion of the rectangular panel W come closer to each other. In the worst case, the film front end portion 10a and the rectangular panel W There may be contact with the front end.

  Therefore, in the present invention, until the detection of the film front end portion 10a is finished, the rectangular panel W of the sheet-shaped polarizing film 10 whose front end portion is stopped for detection of the film front end portion 10a. It stands by at a position where it is as close as possible to the film front end 10a and the film front end 10a does not contact the front end of the rectangular panel W. When the configuration 700 is viewed from the side as shown in FIG. 7B, the rectangular panel W has a straight line connecting the front end of the rectangular panel W and the front end of the peeling means 201 on the surface of the rectangular panel W. It is preferable to wait on the upstream side of the position perpendicular to the vertical position, and wait at a position where the straight line connecting the front end portion of the rectangular panel W and the front end portion of the peeling means 201 is perpendicular to the surface of the rectangular panel W. Is more preferable.

  The position of the rectangular panel W may be different when the detection of the film front end portion 10a of the sheet-like polarizing film 10 starts and ends. In this case, the rectangular panel W is conveyed during detection of the film front end portion 10a, and a straight line connecting the front end portion of the rectangular panel W and the front end portion of the peeling means 201 is formed on the surface of the rectangular panel W at the end of detection. On the other hand, it stands by at a position that is vertical.

  Next, the processing from the detection of the film front end portion 10a to the completion of the alignment of the film front end portion 10a to the bonding reference position will be described with reference to FIG. First, when the film front end portion 10a of the sheet-like polarizing film 10 reaches the vicinity of the detection position, the conveyance of the sheet-like polarizing film 10 is temporarily stopped, and light is irradiated from the light source 204 toward the film front end portion 10a (FIG. 9 s1). The light may be constantly emitted from the light source 204 toward the detection position. Next, the sheet-like polarizing film 10 is advanced so that the film front end portion 10a falls within the imaging range (s2 in FIG. 9). This is the distance from the calculated film front end position of the sheet-like polarizing film 10 to the film reference position after the sheet-like polarizing film 10 and the rectangular panel W are pasted together. Is calculated, and the sheet-like polarizing film 10 is advanced by that amount.

  Next, a part of the sheet-like polarizing film 10 including the film front end portion 10a is imaged by the image acquisition unit 203 (s3 in FIG. 9). The magnitude | size and position of an imaging range are not specifically limited, What is necessary is just a magnitude | size and position required for the detection of the film front-end part 10a. The imaging position is preferably two corners of the film front end 10a. The size of the imaging range is appropriately determined in consideration of time and accuracy for capturing the sheet-shaped polarizing film 10 in the imaging range. The captured image is output to the film front end identifying means 205.

  The film front end identifying means 205 detects the film front end 10a from the received image (s4 in FIG. 9). First, the film front end identifying means 205 converts the acquired image that has received the image into a binarized image using only white and black. Binarization is performed by obtaining the brightness of each pixel in the image, and setting the pixel to white if the brightness is greater than a certain threshold that is set as appropriate, and black if it is smaller. The film front end identifying means 205 scans the binarized image and recognizes a straight line that can be recognized as a bright portion as the film front end 10. In one embodiment of the present invention, it is preferable that scanning is performed from the downstream side in the feeding direction of the sheet-like polarizing film 10 toward the upstream side in the binarized image. This is because there is no member in the background on the downstream side in the feed direction of the sheet-like polarizing film 10 in the image, so that the downstream side is surely darker than the other parts, and scanning starts from a darker part. This is for more reliably detecting the film front end.

  When the film front end portion 10a is detected in the image, the position of the film front end portion 10a is obtained (s5 in FIG. 9). As described above, the position of the film front end portion 10a is determined based on the position of the film front end portion 10a captured as a bright portion on a straight line in the image captured by the image acquisition unit 203, and a film reference set in advance in the image. It is obtained by calculating the distance to the position.

  When the position of the film front end portion 10a is calculated, when the alignment between the sheet-like polarizing film 10 and the rectangular panel W is performed before the bonding position, a preset bonding reference position is detected. The difference from the position of the film front end portion 10a is obtained, and the sheet-like polarizing film 10 is advanced by the difference (s6 in FIG. 9). When the alignment between the sheet-like polarizing film 10 and the rectangular panel W is performed at the bonding position, this process is not necessary.

  FIG. 10 is an experimental result showing the effect of improving the bonding accuracy between the sheet-like polarizing film and the rectangular panel when the film front end detection method according to the present invention is used. The vertical axis of the graph in FIG. 10A indicates the amount of deviation of the sheet-like polarizing film from the design position (“0” on the vertical axis of the graph) to be bonded to the rectangular panel as “bonding accuracy”. ing. The horizontal axis is the sample number of the measured sample.

  The graph shown as “before improvement” in FIG. 10A shows the position of the front end of the film using the conventional configuration 600 (FIG. 4) for detecting the front end of the film on the peeling means, and polarization based on the detected position. The data of the bonding accuracy of each sample when a film and a rectangular panel are bonded together are shown. On the other hand, the graph shown as “after improvement” is a case where the position of the film front end is detected using the configuration 700 for detecting the film front end at the bonding position, and the polarizing film and the rectangular panel are bonded based on the detected position. The data of the bonding accuracy of each sample in are shown. Legends 3, 4, 7, and 8 in the graph of FIG. 10 (a) are, as shown in FIG. 10 (b), the front end (positions 3 and 4) and the rear as viewed in the feeding direction of the sheet-like polarizing film. The data of the deviation | shift amount from the design position of a feed direction in the edge part (position of 8 and 7) is shown.

  From the graph of FIG. 10, when using the conventional configuration for detecting the film front end on the peeling means, the bonding accuracy was about ± 1.0 mm at the maximum, but in the bonding position according to the present invention. When the structure which detects a film front-end part is used, it turns out that the bonding precision is settled in the range of about ± 0.5 mm. FIG. 10 also shows data on the amount of deviation from the design position in the lateral direction at the side ends (positions 1, 2, 5, and 6) when viewed in the feeding direction of the sheet-like polarizing film. Yes. From this result, it can be seen that by using the configuration according to the present invention, the bonding accuracy in the lateral direction with respect to the feeding direction of the sheet-like polarizing film is greatly improved. This is due to the following reason. That is, when an angle shift occurs between the sheet-like polarizing film 10 and the rectangular panel W, the angle of the rectangular panel W is corrected in the alignment process with the sheet-like polarizing film 10. In such a case, the rectangular panel W, after alignment, for example, proceeds in the conveyance direction while maintaining a certain angle (corrected angle) with respect to the long side direction and reaches the bonding position. Therefore, the larger the amount of displacement at the film front end portion 10a, the larger the amount of displacement in the lateral direction (that is, the short side direction of the rectangular panel W). Therefore, the bonding accuracy in the lateral direction is also improved by improving the bonding accuracy at the film front end and reducing the shift amount. The graph shown as the horizontal improvement in FIG. 10 illustrates this.

DESCRIPTION OF SYMBOLS 1 Continuous manufacturing apparatus 10 Sheet-like polarizing film 10a Film front end part 12 Adhesive layer 13 Surface protective film 14 which has an adhesive surface Continuous web-like carrier film 16 Cut line 100 Film conveyance apparatus 110 Supporting apparatus 120 Reading apparatus 150 Cutting apparatus 160 Cutting position Confirming device 170 Winding device 200 Laminating device 201 Peeling means 202 Laminating roller 203 Image acquisition means 204 Light source 300 Rectangular panel conveying device 350 Product panel conveying device 400 Control device 600 Conventional configuration 700 Configuration according to the present invention

Claims (14)

A plurality of sheet-like polarizing films laminated on one surface of a continuous web-like carrier film via an adhesive layer are sequentially peeled from the continuous web-like carrier film together with the adhesive layer, and a rectangular panel is formed by the adhesive layer at a bonding position. And manufacturing a product panel continuously,
Peeling a part of the sheet-like polarizing film from the continuous web-like carrier film, bringing the film front end of the sheet-like polarizing film closer to the bonding position with the rectangular panel;
Light having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side of the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film Irradiating toward the front end of the film,
Imaging a region irradiated with light of the sheet-like polarizing film, and obtaining an image;
Identifying the film front end based on the difference in brightness between the image of the film front end that appears in the image and the image of a portion other than the film front end;
Aligning the sheet-shaped polarizing film and the rectangular panel based on the information on the position of the identified film front end,
Bonding the sheet-like polarizing film and the rectangular panel;
A method for continuously producing a product panel, comprising: The said rectangular panel is conveyed to the said bonding position after the step which aligns the said sheet-like polarizing film and the said rectangular panel. The continuous manufacturing method of the product panel of Claim 1 characterized by the above-mentioned.   The said rectangular panel is conveyed to the said bonding position in the case of the step which aligns the said sheet-like polarizing film and the said rectangular panel, The continuous manufacturing method of the product panel of Claim 1 characterized by the above-mentioned.   In the step of irradiating light toward the film front end, light having an optical axis that forms an angle smaller than 45 ° with respect to the feeding direction of the sheet-like polarizing film is irradiated toward the film front end. The continuous manufacturing method of the product panel according to any one of claims 1 to 3. The product according to any one of claims 1 to 3, wherein a region irradiated with light is imaged from a side opposite to the adhesive layer of the sheet-like polarizing film. Panel continuous manufacturing method.   In the step of identifying the film front end, the image is scanned from the direction corresponding to the downstream side in the feeding direction of the sheet-shaped polarizing film to the direction corresponding to the upstream side, and the bright portion in the image is identified as the film front end. The continuous manufacturing method of the product panel according to any one of claims 1 to 3, characterized in that: A plurality of sheet-like polarizing films laminated on one surface of a continuous web-like carrier film via an adhesive layer are sequentially peeled from the continuous web-like carrier film together with the adhesive layer, and a rectangular panel is formed by the adhesive layer at a bonding position. A detection system for detecting a film front end portion of the sheet-like polarizing film peeled off before being used in an apparatus for continuously manufacturing a product panel by bonding,
Light having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side of the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film At least one light source that irradiates the front end of the film,
At least one image acquisition means for capturing an image by imaging the region irradiated with the light of the sheet-shaped polarizing film;
A film front end identifying means for identifying the film front end based on a difference in brightness between an image of the film front end appearing in the image and an image of a portion other than the front end;
A detection system comprising:   The detection system according to claim 6, wherein the optical axis and the feeding direction of the sheet-like polarizing film form an angle smaller than 45 °.   The detection system according to claim 6, wherein the image acquisition unit images a region irradiated with light from a side opposite to the adhesive layer of the sheet-like polarizing film.   The film front end identifying means scans the image in a direction corresponding to the upstream side from the direction corresponding to the downstream side in the feeding direction of the sheet-like polarizing film, and identifies the bright portion in the image as the film front end. The detection system according to claim 6, wherein: A plurality of sheet-like polarizing films laminated on one surface of a continuous web-like carrier film via an adhesive layer are sequentially peeled from the continuous web-like carrier film together with the adhesive layer, and a rectangular panel is formed by the adhesive layer at a bonding position. And a detection method for detecting the film front end portion of the sheet-like polarizing film peeled off before being used in an apparatus for continuously producing a product panel by bonding,
Light having an optical axis that forms an acute angle with respect to the feeding direction of the sheet-like polarizing film from the upstream side of the feeding direction of the sheet-like polarizing film on the side opposite to the adhesive layer of the sheet-like polarizing film Irradiating toward the front end of the film,
Imaging the region irradiated with the light of the sheet-like polarizing film, and obtaining an image;
Identifying the front edge based on the difference in brightness between the image of the film front edge that appears in the image and the image of a portion other than the front edge; and
A detection method comprising:   In the step of irradiating light toward the film front end, light having an optical axis that forms an angle smaller than 45 ° with respect to the feeding direction of the sheet-like polarizing film is irradiated toward the film front end. The detection method according to claim 11. The detection method according to claim 11, wherein a region irradiated with light is imaged from a side opposite to the adhesive layer of the sheet-like polarizing film.   The film front end identifying step scans the image from a direction corresponding to the downstream side in the feeding direction of the sheet-shaped polarizing film to a direction corresponding to the upstream side, and identifies a bright portion in the image as the film front end. The method for continuously producing a product panel according to claim 11, comprising: