JP7587966B2 - Manufacturing method of laminated optical film, printing device, and manufacturing device of laminated optical film - Google Patents

Description

The present invention relates to a method for manufacturing a laminated optical film, a printing device, and an apparatus for manufacturing a laminated optical film.

As an optical film, there is a laminated optical film in which a first optical film (e.g., a polarizing film) is laminated with another second optical film (e.g., a surface protective film), such as a polarizing film with a surface protective film. Such a laminated optical film can be manufactured, for example, by preparing a long laminated optical film in which a second optical film is laminated on a long first optical film, and cutting out a laminated optical film of the desired size (e.g., product size) from the laminated optical film.

In the process of manufacturing a long laminated optical film, a technique for determining the position of a defect occurring in the laminated optical film is known, for example, as described in Patent Document 1. Patent Document 1 discloses a technique for performing a defect inspection in the manufacturing process of the laminated optical film, printing an identification code (information code) indicating defect position information on an end portion in the width direction of the long laminated optical film, and reading the identification code to apply a marking to the defect position.

JP 2009-244064 A

When printing an identification code indicating defect position information on the widthwise end of a long laminated optical film as in the technology described in Patent Document 1, the area to be printed cannot be used as an area for cutting out a sheet-like laminated optical film (for example, a laminated optical film of product size) from the long laminated optical film. Therefore, when laminating a second optical film on a first optical film, it is possible to shift the end of the second optical film from the position of the end of the first optical film in advance to secure a non-used area (end area), and to print the identification code in the non-used area. However, due to meandering during transport of the long laminated optical film, the position of the non-used area may shift from the designed position during the transport process. As a result, there are problems such as the identification code being printed in the used area or the identification code being missing beyond the range of the laminated optical film.

The object of the present invention is to provide a method for manufacturing a laminated optical film on which a reliably readable information code is printed while leaving more area available other than the area for printing the information code, a printing device, and a laminated optical film manufacturing device.

A method for manufacturing a laminated optical film according to one aspect of the present invention includes an end region detection step for detecting an end region in the width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film, and a printing step for printing an information code recording information about the laminated optical film in the end region detected in the end region detection step, in which the second optical film is laminated on the first optical film so that the first optical film is exposed when viewed from the second optical film side in the end region, and the end region detection step includes an irradiation step for irradiating the laminated optical film with illumination light having a striped pattern in which light and dark parts are alternately arranged, a light detection step for detecting reflected light, which is the illumination light reflected by the laminated optical film, and an end region identification step for identifying the end region based on the detection result of the reflected light.

In the above-mentioned manufacturing method of a laminated optical film, the edge region is detected by an edge region detection process. At this time, illumination light having a stripe pattern is irradiated onto the laminated optical film. Since the edge region can be reliably detected with illumination light having a stripe pattern, the edge region can be accurately detected. In the above-mentioned manufacturing method, the printing unit prints an information code in the edge region based on the detection result of the edge region in the edge region detection process. Therefore, the information code can be printed in a readable state in the edge region while securing more area other than the edge region in the laminated optical film for printing the information code.

In the end region identification process, the end region may be identified by obtaining positional information of the end of the first optical film and the end of the second optical film that define both ends of the end region in the width direction based on the detection result of the reflected light.

The stripe pattern may periodically change into a plurality of patterns, and in the edge region identification process, the edge region may be identified based on detection results corresponding to the plurality of patterns. In this case, since the stripe pattern periodically changes into a plurality of patterns, more optical information can be obtained. As a result, it is easier to accurately identify the edge region.

The stripe pattern may vary periodically between the first pattern and the second pattern, and the extension direction of the bright and dark portions in the second pattern may be perpendicular to the extension direction of the bright and dark portions in the first pattern. The width of at least one of the bright and dark portions may vary periodically.

The edge region detection process and the printing process may be carried out while the laminated optical film is being transported in the longitudinal direction using multiple transport rollers. Even if the laminated optical film is transported in this manner, by carrying out the edge region detection process, it is possible to print an information code in the edge region in the printing process.

In the irradiation process, the illumination light may be irradiated onto the laminated optical film located on at least one of the plurality of conveying rollers. Since the stripe pattern has light and dark areas, it is possible to capture multiple images with illumination from multiple directions. Therefore, the obtained images can be analyzed to generate unevenness images and texture images, making it possible to stably detect the edge region without being dependent on the surface condition or measurement environment.

In the irradiation process, the illumination light may be irradiated onto the laminated optical film located between two adjacent conveying rollers among the plurality of conveying rollers.

A printing device according to another aspect of the present invention includes an end region detection unit that detects an end region in the width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film, and a printing unit that prints an information code that records information about the laminated optical film in the end region detected by the end region detection unit. The end region detection unit includes a light source unit that irradiates the laminated optical film with illumination light having a striped pattern in which light and dark areas are arranged alternately, a light detection unit that detects reflected light, which is the illumination light reflected by the laminated optical film, and an end region identification unit that identifies the end region based on the detection result of the reflected light.

The printing device detects the edge region by the edge region detection unit. The light source unit of the edge region detection unit irradiates the laminated optical film with illumination light having a stripe pattern. The illumination light having a stripe pattern can reliably detect the edge region, so the edge region can be detected accurately. In the printing device, the printing unit prints an information code in the edge region based on the detection result of the edge region by the edge region detection unit. Therefore, the information code can be printed in a readable state in the edge region while securing more area other than the edge region in the laminated optical film for printing the information code.

The printing device according to one embodiment may further include a transport mechanism that transports the laminated optical film in the longitudinal direction, and the end region detection unit and the printing unit may be arranged along a transport path of the laminated optical film by the transport mechanism. Even if the laminated optical film is transported in this manner, by providing the end region detection unit, the printing unit can print an information code in the end region.

An apparatus for manufacturing a laminated optical film according to yet another aspect of the present invention includes the above-mentioned printing device.

The present invention provides a method for manufacturing a laminated optical film on which a reliably readable information code is printed while leaving more space in areas other than the area for printing the information code, a printing device, and a laminated optical film manufacturing device.

FIG. 1 is a diagram illustrating the configuration of a laminated optical film produced by a method for producing a laminated optical film according to one embodiment. FIG. 2 is a partially enlarged plan view of the laminated optical film. FIG. 3 is a flow chart of an example of a method for producing a laminated optical film. FIG. 4 is a schematic diagram for explaining a method for producing a laminated optical film. FIG. 5 is a schematic diagram for explaining the edge region detection unit. FIG. 6 is a diagram showing a first pattern which is an example of a stripe pattern. FIG. 7 is a diagram showing a second pattern which is another example of the stripe pattern. FIG. 8 is a flowchart of an example of an edge region detection process.

Below, an embodiment of the present invention will be described with reference to the drawings. Identical elements are given the same reference numerals, and duplicate explanations will be omitted. The dimensional ratios in the drawings do not necessarily match those in the description.

Figure 1 is a diagram illustrating the configuration of a laminated optical film manufactured by one embodiment of a method for manufacturing a laminated optical film. Figure 2 is a partially enlarged plan view of the laminated optical film. The laminated optical film 10 shown in Figures 1 and 2 is a long film, and Figure 1 shows a schematic cross section perpendicular to the long direction.

As shown in Figures 1 and 2, the laminated optical film 10 is a polarizing film with a surface protective film, in which a surface protective film (second optical film) 12 is laminated on a polarizing film (first optical film) 11. The laminated optical film 10 is a raw roll for obtaining a sheet-shaped laminated optical film of a desired size (e.g., product size).

For ease of explanation, the longitudinal direction of the laminated optical film 10 is also referred to as the x-direction, the direction perpendicular to the longitudinal direction of the laminated optical film 10 (width direction) as the y-direction, and the thickness direction of the laminated optical film 10 (corresponding to the lamination direction of the polarizing film 11 and the surface protection film 12) as the z-direction.

The polarizing film 11 is a laminated film in which a protective film is attached to a polarizer. The polarizer is, for example, a polyvinyl alcohol-based film dyed with a dichroic pigment (such as iodine or a dichroic dye) and stretched. The thickness of the polarizer is, for example, 1 μm to 150 μm. Examples of materials for the protective film include cellulose acetate-based resins (such as triacetyl cellulose (TAC)), norbornene-based resins, polycarbonate-based resins, and acrylic-based resins. In terms of polarization properties and durability, triacetyl cellulose is preferred as the material for the protective film. The thickness of the protective film is, for example, 100 μm or less, preferably 60 μm or less, and more preferably 50 μm or less. The protective film is bonded to the polarizer via, for example, an adhesive layer or a pressure-sensitive adhesive layer.

The material of the adhesive layer may be an adhesive known in the technical field related to this disclosure. Examples of adhesives include active energy ray curing adhesives such as ultraviolet (UV) curing resins, and water-based adhesives such as polyvinyl alcohol-based resin aqueous solutions. The material of the adhesive layer may be an adhesive known in the technical field related to this disclosure. Examples of adhesives include adhesive compositions mainly composed of (meth)acrylic resins, rubber-based resins, urethane-based resins, ester-based resins, silicone-based resins, polyvinyl ether-based resins, etc.

The surface protection film 12 is a film that protects the surface of the polarizing film 11, and is bonded to the polarizing film 11, for example, via an adhesive layer. Examples of adhesives that form this adhesive layer are the same as those that form the adhesive layer between the polarizer and the protective film. The thickness of the surface protection film 12 is, for example, 30 μm to 100 μm. Examples of materials for the surface protection film 12 include polyethylene, polypropylene, polyester, etc.

As shown in FIG. 1, the width (length in the y direction) of the surface protection film 12 is shorter than the width of the polarizing film 11. The surface protection film 12 is laminated to the polarizing film 11 so that the polarizing film 11 is partially exposed when viewed from the z direction. Specifically, in the y direction, the position of the end 11a of the polarizing film 11 and the position of the end 12a (the end on the same side as the end when viewed from the z direction) of the surface protection film 12 are misaligned. In this embodiment, the position of the end 11b (the end opposite to the end 11a) of the polarizing film 11 and the end 12b (the end opposite to the end 12a) of the surface protection film 12 are aligned in the y direction.

The region between end 11a and end 12a when viewed from the z direction is referred to as end region 10A. In the laminated optical film 10, the region other than end region 10A (the region where polarizing film 11 and surface protection film 12 overlap) is the region (hereinafter referred to as "used region 10B") used to cut out the laminated optical film (sheet of laminated optical film) of the desired size.

The edge region 10A is a region where the polarizing film 11 is exposed when the laminated optical film 10 is viewed from the surface protection film 12 side. As shown in FIG. 2, the edge region 10A is a region where an information code 100 regarding the laminated optical film 10 is printed, and is an unused region that is not used to cut out the laminated optical film (a sheet of laminated optical film) of the desired size.

The information recorded in the information code 100 is, for example, information on a defect inspection performed in the manufacturing process of the laminated optical film 10 (defect information), position information in the longitudinal direction (distance from the tip, etc.), etc. In this embodiment, unless otherwise specified, the information code 100 is a code in which defect information (for example, defect position information) is recorded. The information code 100 may be a QR code (registered trademark) or a barcode, as shown in FIG. 2. The end area 10A is set to a size that allows the information code 100 to be printed and allows the use area 10B to be utilized to the maximum extent. When the information code 100 is a QR code, for example, in addition to the code itself (area in which information is recorded) having a square shape with one side of 5.25 mm , a margin of 2 mm width (area indicated by a dashed line around the QR code in FIG. 2) must be secured. Therefore, when a QR code of the above size is adopted for the information code 100, the width of the end area 10A (the distance between the end 11a and the end 12a in the y direction) is preferably about 10 mm.

Next, an example of a method for manufacturing the laminated optical film 10 will be described. Figure 3 is a flowchart of an example of a method for manufacturing the laminated optical film 10.

As shown in FIG. 3, the manufacturing method of the laminated optical film 10 includes a step of laminating the polarizing film 11 and the surface protection film 12 (lamination step S10), a step of inspecting the surface or interior of the laminated optical film 10 for defects (scratches, foreign matter, air bubbles, etc.) to obtain defect information (including defect position information), a step of detecting the end region 10A (end region detection step S30), and a step of printing an information code 100 including the defect information obtained in the defect inspection step S20 on the end region 10A detected in the end region detection step S30 (printing step S40).

The lamination process S10, defect inspection process S20, edge region detection process S30, and printing process S40 can be performed while transporting the long polarizing film 11 and surface protection film 12 in the long direction, as shown in FIG. 4. An example of a method for manufacturing the laminated optical film 10 will be specifically described using FIG. 4.

The long polarizing film 11 and surface protection film 12 are transported in the longitudinal direction and bonded in the bonding unit 21 (bonding process S10). The bonding unit 21 has a pair of rollers 21A, 21B. The polarizing film 11 and surface protection film 12 are transported in a stacked state between the pair of rollers 21A, 21B, and the polarizing film 11 and surface protection film 12 are pressed in the thickness direction by the pair of rollers 21A, 21B, thereby bonding the polarizing film 11 and surface protection film 12 and obtaining the laminated optical film 10.

When the polarizing film 11 and the surface protection film 12 are transported between the pair of rollers 21A, 21B, the polarizing film 11 and the surface protection film 12 are aligned so that the end region 10A is formed. In order to bond the polarizing film 11 and the surface protection film 12, for example, the above-mentioned adhesive layer may be provided on the surface of the surface protection film 12 facing the polarizing film 11.

The laminated optical film 10 obtained by laminating the polarizing film 11 and the surface protection film 12 by the laminating unit 21 is transported toward the winding unit 23 via a number of transport rollers 22. Although two transport rollers 22 are shown as an example in FIG. 3, the number of transport rollers 22 can be set appropriately according to the transport length.

In the transport direction of the laminated optical film 10, a defect inspection device 30 is disposed downstream of the bonding unit 21. The defect inspection device 30 inspects the surface or interior of the laminated optical film 10 for defects (such as scratches, foreign matter, and air bubbles) (defect inspection process S20). Information on defects occurring in the laminated optical film 10 (hereinafter referred to as "defect information") is obtained by the defect inspection by the defect inspection device 30. The defect information includes position information of the defect (for example, the position of the defect in the width direction of the laminated optical film 10).

The defect inspection device 30 shown in FIG. 4 is a transmission type defect inspection device. In the defect inspection device 30, inspection light is output from a light source unit 31 arranged on one side of the laminated optical film 10 to illuminate the laminated optical film 10, while an image capturing unit 32 arranged on the other side of the laminated optical film 10 captures an image of the laminated optical film 10. Defects can be detected by analyzing the image data obtained by the image capturing unit 32 with an image processing device (not shown).

The wavelength of the light output by the light source unit 31 depends on the materials of the polarizing film 11 and the surface protection film 12, and may be any wavelength that allows an image of the area irradiated with the inspection light to be obtained. An example of the light output from the light source unit 31 is white light having a peak wavelength of 450±30 nm. The light source unit 31 can provide uniform illumination over the entire width of the laminated optical film 10, for example. The light source unit 31 can be a tubular light emitter such as a fluorescent lamp or a linear light source such as a transmission light. The transmission light has a powerful light source such as a metal halide lamp arranged on the axial end face of a rod-shaped light guide, and guides the light incident on the end face to the side between both end faces, functioning as a rod-shaped light source. The light source unit 31 can also be one in which multiple LED light sources are arranged in the width direction of the laminated optical film 10.

The imaging unit 32 may be a camera (two-dimensional sensor) such as a CCD camera or a CMOS camera, or a line sensor. When imaging the laminated optical film 10 with a camera such as a CCD camera, if one camera cannot image the entire width of the laminated optical film 10 at once, the imaging unit 32 may have multiple cameras arranged along the width of the laminated optical film 10.

In order to detect defects with high sensitivity, the defect inspection device 30 may adopt a configuration in which the laminated optical film 10 is illuminated via a polarizing plate arranged in a crossed Nicol state with respect to the polarizing film 11 between the light source unit 31 and the laminated optical film 10, depending on the defect to be detected, or may adopt a configuration in which the laminated optical film 10 is imaged via a polarizing plate arranged in a crossed Nicol state with respect to the polarizing film 11 between the polarizing film 11 and the imaging unit 32.

Although a transmission-type defect inspection device has been described as the defect inspection device 30, a reflection-type defect inspection device (i.e., a configuration in which the light source unit 31 and the imaging unit 32 are arranged on the same side of the laminated optical film 10) may also be used in the defect detection process S20. Two defect inspection devices, a transmission-type defect inspection device and a reflection-type defect inspection device, may also be used in the defect detection process S20. In this case, defects that can be detected with good sensitivity by the transmission-type defect inspection device and defects that can be detected with good sensitivity by the reflection-type defect inspection device can each be detected, so that defects occurring in the laminated optical film 10 can be reliably detected.

In the transport direction of the laminated optical film 10, downstream of the defect inspection device 30, a printing device 40 is disposed, which prints defect information on the laminated optical film 10. The printing device 40 has an end region detection unit 41, a printing unit 42 disposed downstream of the end region detection unit 41, and a control device 43 that controls the end region detection unit 41 and the printing unit 42.

In the printing device 40, defect information of the defects detected by the defect inspection device 30 is input to the control device 43. In the printing device 40, the control device 43 controls the end area detection unit 41 to detect the end area 10A in the laminated optical film 10 (end area detection process S30). Thereafter, the control device 43 controls the printing unit 42 to print an information code 100 (e.g., a QR code) indicating the defect information of the defect detected by the defect inspection device 30 in the end area 10A detected by the end area detection unit 41 (printing process S40). The information code 100 may be created in advance by an image processing device possessed by the defect inspection device 30 and input to the control device 43, or may be created by the control device 43 (or the printing unit 42) based on the defect information input from the defect inspection device 30.

The printing unit 42 is a printing device configured to be able to adjust the printing position, for example, a printing device using laser light. In this case, the printing position can be adjusted by adjusting the irradiation position of the laser light. A printing device capable of printing QR codes, bar codes, etc. can be used as the printing unit 42. The printing unit 42 can be positioned close to the end region detection unit 41 to the extent that it is not affected by the meandering of the laminated optical film 10, etc.

The laminated optical film 10 on which the information code 100 is printed by the printing device 40 is wound into a roll by the winding section 23. This results in a laminated optical film 10 (or a roll of laminated optical film) on which the information code 100 is printed.

In the example shown in FIG. 4, the laminating unit 21, the transport roller 22, the defect inspection device 30, the printing device 40, and the winding unit 23 constitute the laminated optical film manufacturing device 1. The transport roller 22 contributes to the transport of the laminated optical film 10, and is therefore part of the transport mechanism 20. Similarly, the laminating unit 21 and the winding unit 23 also contribute to the transport of the laminated optical film 10, and are therefore also part of the transport mechanism 20. In the example shown in FIG. 4, the end region detection unit 41 detects the end region 10A while transporting the laminated optical film 10, and the printing unit 42 prints the information code 100 on the end region 10A. Therefore, the transport mechanism 20 is also part of the printing device 40.

In order to obtain a laminated optical film 10 of a desired size (a laminated optical film in a sheet) from the laminated optical film 10 on which the information code 100 is printed, a process of singulating the laminated optical film 10 on which the information code 100 is printed into pieces of the desired size can be carried out. In this case, by reading the information code 100 before the singulation process, it is possible to identify a laminated optical film of the desired size that contains the defect indicated by the information code 100.

Next, the edge region detection unit 41 of the printing device 40 will be described with reference to FIG. 5. FIG. 5 is a schematic diagram for explaining the edge region detection unit 41.

The edge region detection unit 41 includes a reflective optical system 411 and an analysis device 412.

The reflective optical system 411 is an optical system for acquiring an image of a predetermined area in the laminated optical film 10. In the example shown in FIG. 5, the predetermined area is the vicinity of the end area 10A of the laminated optical film 10 (the area including the end area 10A). The predetermined area only needs to cover the range of variation of the end area 10A, including the amount of deviation caused by meandering, etc., relative to the designed position of the end area 10A assumed by the transport path. The reflective optical system 411 has a light source unit 41A and an imaging unit (light detection unit) 41B.

The light source unit 41A outputs illumination light L1 toward a predetermined area of the laminated optical film 10. As shown in FIG. 5, the light source unit 41A is arranged to irradiate the illumination light L1 to the laminated optical film 10 located between adjacent transport rollers 22. The light source unit 41A may be arranged to irradiate the illumination light L1 to the laminated optical film 10 located on the transport roller 22.

The wavelength of the illumination light L1 depends on the materials of the polarizing film 11 and the surface protection film 12, and may be any wavelength that allows an image of a specified area to be obtained. An example of the light source unit 41A is a white LED light source that can output white illumination light L1 with a peak wavelength of 450±30 nm. The illumination light L1 is configured to illuminate a specified area in a planar manner, for example.

The light source unit 41A will be further described with reference to Figures 6 and 7. As shown in Figures 6 and 7, the light source unit 41A outputs illumination light L1 having a stripe pattern 44 in which light portions 44a and dark portions 44b are alternately arranged. The X direction in Figure 6 indicates the extension direction of the light portions 44a and dark portions 44b in Figure 6, and the Y direction is a direction perpendicular to the X direction. The X direction and Y direction in Figure 7 are the same directions as the X direction and Y direction in Figure 6. The X direction or Y direction shown in Figures 6 and 7 can be set to, for example, the transport direction of the laminated optical film 10.

The shape (pattern shape) of the stripe pattern 44 may change periodically to a plurality of patterns. For example, in Figs. 6 and 7, the light portions 44a (or the dark portions 44b) may move in the direction of the arrows in Figs. 6 and 7, or the width of the light portions 44a (or the dark portions 44b) may change periodically. The shape of the stripe pattern 44 may be controlled, for example, by the analysis device 412 (see Fig. 5). In this case, the analysis device 412 may control the light source unit 41A and the imaging unit 41B so as to synchronize them.

When the stripe pattern 44 shown in FIG. 6 is called the first pattern 44A and the stripe pattern 44 shown in FIG. 7 is called the second pattern 44B, the light source unit 41A may be configured to periodically vary between the first pattern 44A and the second pattern 44B. The second pattern 44B is a pattern in which the extension direction of the light portion 44a and the dark portion 44b in the second pattern 44B is perpendicular to the extension direction of the light portion 44a and the dark portion 44b in the first pattern 44A. Even when the light portion 44a and the second pattern 44B periodically vary between the first pattern 44A and the second pattern 44B, the light portion 44a (or the dark portion 44b) may move in the direction of the arrow in FIG. 6 and FIG. 7, or the width of the light portion 44a (or the dark portion 44b) may vary in each of the first pattern 44A and the second pattern 44B.

The light source unit 41A may include, for example, a light source in which multiple point light sources (e.g., LEDs) are arranged two-dimensionally, and a control device that controls the lighting state of each LED. In this case, the control device can form light areas 44a and dark areas 44b by controlling the lighting state of the multiple LEDs. Furthermore, the stripe pattern 44 formed by the light areas 44a and dark areas 44b can be changed into multiple patterns. The function of controlling the lighting state of each LED may be implemented, for example, by the analysis device 412 (or the control device 43).

Returning to FIG. 5, the imaging unit 41B will be described. The imaging unit 41B is a photodetector that detects reflected light L2, which is illumination light L1 reflected by a predetermined area. The imaging unit 41B is, for example, a two-dimensional sensor such as a CCD camera or a CMOS camera. The imaging unit 41B inputs image data to the analysis device 412. Examples of input methods include a method using wired communication and a method using wireless communication.

The analysis device (end region identification unit) 412 is a device for identifying the end region 10A based on image data input from the imaging unit 41B. The analysis device 412 processes the image data input from the imaging unit 41B to create an image of a specific region, and analyzes the created image to identify the end region 10A (specifically, to identify the position of the end region 10A of the laminated optical film 10 being transported). Therefore, the analysis device 412 may have an image processing unit and an end region identification unit based on the image created by the image processing unit.

For example, the analysis device 412 identifies the end region 10A by acquiring position information of the end 11a and end 12a that define the end region 10A. The positions of the end 11a and end 12a may be positions relative to a reference position of the transport path of the laminated optical film 10 (for example, the edge of a table that supports a roller). Such positions of the end 11a and end 12a can be acquired from the image acquired by the imaging unit 41B and the installation position of the imaging unit 41B (or the position of a reference member reflected in the image).

The analysis device 412 may have at least one of the functions of controlling the imaging timing of the imaging unit 41B and controlling the output of the illumination light L1 of the light source unit 41A.

The analysis device 412 may be, for example, a dedicated device for detecting the end region 10A, or a program for performing the end region identification function including the image processing may be executed in a personal computer, causing the personal computer to function as the analysis device 412. In this embodiment, the analysis device 412 and the control device 43 are described separately, but the analysis device 412 may be the same device as the control device 43, that is, the function of the analysis device 412 may be implemented in the control device 43.

An example of the edge region detection process S30 will be described using FIG. 8. FIG. 8 is a flowchart of an example of the edge region detection process S30.

First, illumination light L1 is irradiated toward a predetermined area of the laminated optical film 10 (irradiation step S31). Reflected light L2, which is the illumination light L1 reflected from the predetermined area, is detected by the imaging unit 41B (light detection step S32). When the illumination light L1 periodically changes to a plurality of patterns (for example, when it periodically varies between the first pattern 44A and the second pattern 44B), the period of change of the stripe pattern 44 and the imaging speed of the imaging unit 41B can be set in consideration of the conveying speed of the laminated optical film 10. Specifically, the period of change of the stripe pattern 44 and the imaging speed of the imaging unit can be set to a degree that allows images of substantially the same area of the laminated optical film 10 to be acquired during the time when the stripe pattern 44 changes between the plurality of patterns a certain number of times.

Based on the image (detection result) of the predetermined area obtained by the light detection process S32, the analysis device 412 acquires position information of the end 11a and end 12a that define the end area 10A, and identifies the end area 10A (end area identification process S33). The above-mentioned end 11a and end 12a may be identified automatically by the analysis device 412, for example, based on edge detection technology in the image.

When the illumination light L1 periodically changes into a plurality of patterns (for example, when it periodically changes between the first pattern 44A and the second pattern 44B), the analysis device 412 may acquire position information of the end 11a and the end 12a based on image data (detection results) obtained for the reflected light L2 in each of the plurality of patterns (for example, the first pattern 44A and the second pattern 44B), and may identify the end region 10A. The analysis device 412 may create an image using image data (detection results) obtained for the reflected light L2 in each of the plurality of patterns (for example, the first pattern 44A and the second pattern 44B), and may use the image to identify the end region 10A. To obtain the single image, the analysis device 412 may control the timing of the shape change of the stripe pattern 44 and the imaging timing of the imaging unit 41B.

After the end region identification process S33 is performed, the information from the end region identification process S33 is input to the control device 43, which controls the printing unit 42 to print defect information at a predetermined position in the end region 10A identified in the end region identification process S33 (printing process S40 shown in the figure). The control device 43 controls the printing timing according to the conveying speed of the laminated optical film 10 so that when a defect detected by the defect inspection device 30 passes the arrangement position of the printing unit 42, the printing unit 42 prints an information code 100 including defect information of the corresponding defect in the end region 10A.

When the laminated optical film 10 is transported in the longitudinal direction, the end region 10A may deviate from its designed position on the transport path due to meandering or other reasons.

In the manufacturing method and printing device 40 of the laminated optical film 10 described above, the end region 10A is detected by the end region detection step S30 (end region detection unit 41) before printing the information code 100. For this detection, the laminated optical film 10 is irradiated with illumination light L1 having a stripe pattern 44. With illumination light L1 having a stripe pattern 44, the angle dependency of the irradiation region of illumination light L1 with respect to the extension direction of end 11a (or end 12a) can be reduced compared to the case of using linear illumination light, for example, and the positions of end 11a and end 12a can be detected more reliably. Furthermore, since illumination light L1 has a stripe pattern 44, it is possible to efficiently obtain multiple images in which one specific region is illuminated from multiple directions. Therefore, end 11a and end 12a can be detected more reliably. Since end 11a and end 12a can be detected appropriately in this way, end region 10A can be accurately detected.

In the above manufacturing method, the printing unit 42 prints the information code 100 at a predetermined position in the end region 10A based on the detection result of the end region 10A in the end region detection step S30. Therefore, as described above, even if the end region 10A is displaced from the designed position of the conveying path due to meandering or the like, the information code 100 can be printed in the end region 10A while preventing a part of the information code 100 from protruding from the end 11a or the information code 100 from overlapping with the end 12a. Since the end region 10A is detected in the end region detection step S30, the effect of meandering can be reduced. Therefore, the width margin of the end region 10A can be made smaller than when meandering or the like is taken into consideration. In other words, the end region 10A can be set so that the use region 10B can be secured to the maximum extent. Therefore, a laminated optical film 10 on which a reliably readable information code 100 is printed can be manufactured while securing a larger area (use region 10B) other than the area for printing the information code in the laminated optical film.

In the above manufacturing method, the information code 100 can be printed in the end region 10A. Therefore, the information code 100 can be reliably read in a later process. As a result, when multiple product laminated optical films are cut out from the laminated optical film 10 (raw laminated optical film) on which the information code 100 is printed, it is possible to reliably sort defect-free films from the multiple product laminated optical films based on the defect information contained in the information code 100.

When the stripe pattern 44 is periodically changed to multiple patterns, multiple pieces of image information can be acquired with one reflective optical system 411. Therefore, even when imaging optically transparent optical films such as the polarizing film 11 and the surface protection film 12, the positions of the end 11a and end 12a can be detected more reliably. As a result, the position of the end region 10A can be detected more accurately.

When the laminated optical film 10 is placed on the transport roller 22, specular reflection is likely to occur on the surface of the transport roller 22. For example, by using the stripe pattern 44, it is possible to capture multiple images illuminated from multiple directions, so that even if the surface of the transport roller 22 is, for example, a mirror surface, the effect of specular reflection on the surface of the transport roller 22 is reduced. Therefore, the end 11a and the end 12a are easy to detect. In other words, even in an environment susceptible to specular reflection, the end 11a and the end 12a are easy to detect. As a result, the end region 10A can be accurately detected.

The above describes an embodiment of the present invention. However, the present invention is not limited to the exemplified embodiment, and is intended to include the scope indicated by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

For example, the first optical film may be a film in which another optical film, such as a retardation film, is laminated on the polarizing film in addition to (or instead of) a protective film. The second optical film may also be, for example, a retardation film, a film having other optical functions, or an optically transparent film-like adhesive layer or pressure-sensitive adhesive layer.

Although the case where an end region is formed on one end side in the width direction of the laminated optical film has been described, an end region may also be formed on the other end side. For example, the end 11b and the end 12b shown in FIG. 1 may be misaligned, and an end region may be formed between them. When end regions are formed on both end sides in the width direction of the laminated optical film, the end region detection process may detect the two end regions by arranging an end region detection unit for each of the two end regions. In this case, the analysis device provided in the end region detection unit may be a common device for the two end regions. When end regions are formed on both end sides in the width direction of the laminated optical film, the printing unit may print on one of the two end regions, or may print an information code containing different defect information in each of the two end regions depending on the defect information.

In FIG. 5, the light source unit 41A and the imaging unit 41B are arranged along the y direction when viewed from the z direction. However, the arrangement of the light source unit 41A and the imaging unit 41B is not limited to the form shown in FIG. 5. The light source unit 41A and the imaging unit 41B may be arranged along the x direction, for example.

For example, if defect inspection is performed on the first optical film and the second optical film during the manufacturing process, the defect information may also be printed on the laminated optical film as an information code. If the information recorded in the information code is other than defect information (for example, position information from the tip of the laminated optical film), the manufacturing method for the laminated optical film (manufacturing apparatus for the laminated optical film) does not need to have a defect inspection process (defect inspection apparatus).

In the example shown in FIG. 5, a lamination step (lamination unit) for laminating a polarizing film (first optical film) and a surface protective film (second optical film) has been described. However, if there is a roll of a laminated optical film in which the second optical film is laminated to the first optical film, the manufacturing method for the laminated optical film (manufacturing apparatus for the laminated optical film) does not need to have a lamination step (lamination unit).

The various embodiments and modifications described above may be combined as appropriate without departing from the spirit of the present invention.

1...Laminated optical film manufacturing apparatus, 10...Laminated optical film, 11...Polarizing film (first optical film), 12...Surface protection film (second optical film), 11a...End, 12a...End, 10A...End region, 20...Conveying mechanism, 40...Printing device, 41...End region detection unit, 42...Printing unit, 44...Striped pattern, 44A...First pattern, 44B...Second pattern, 44a...Bright area, 44b...Dark area, 412...Analysis device (end region identification unit), 41A...Light source unit, 41B...Imaging unit (photodetector), 100...Information code, L1...Illumination light, L2...Reflected light.

Claims (18)

an end region detection step of detecting an end region in a width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film;
a printing step of printing an information code recording information about the laminated optical film in the edge region detected in the edge region detection step;
Equipped with
the second optical film is laminated on the first optical film in the end region such that the first optical film is exposed when viewed from the second optical film side,
The edge region detection step includes:
an irradiation step of irradiating the laminated optical film with illumination light having a stripe pattern in which light areas and dark areas are alternately arranged;
a light detection step of detecting reflected light, which is the illumination light reflected by the laminated optical film;
an end region identifying step of identifying the end region based on a result of the detection of the reflected light;
having
the first optical film and the second optical film are optically transparent;
A method for producing a laminated optical film. The stripe pattern periodically changes into a plurality of patterns,
In the edge region specifying step, the edge region is specified based on detection results corresponding to the plurality of patterns.
A method for producing the laminated optical film according to claim 1 . the stripe pattern periodically changes between a first pattern and a second pattern;
An extension direction of the bright portion and the dark portion in the second pattern is perpendicular to an extension direction of the bright portion and the dark portion in the first pattern.
The method for producing the laminated optical film according to claim 2 . The width of at least one of the bright portion and the dark portion changes periodically.
A method for producing the laminated optical film according to claim 2 or 3. an end region detection step of detecting an end region in a width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film;
a printing step of printing an information code recording information about the laminated optical film in the edge region detected in the edge region detection step;
Equipped with
the second optical film is laminated on the first optical film in the end region such that the first optical film is exposed when viewed from the second optical film side,
The edge region detection step includes:
an irradiation step of irradiating the laminated optical film with illumination light having a stripe pattern in which light areas and dark areas are alternately arranged;
a light detection step of detecting reflected light, which is the illumination light reflected by the laminated optical film;
an end region identifying step of identifying the end region based on a result of the detection of the reflected light;
having
the stripe pattern periodically changes into a plurality of patterns by periodically changing the width of the bright portion or the dark portion,
In the edge region specifying step, the edge region is specified based on detection results corresponding to the plurality of patterns.
A method for producing a laminated optical film. the stripe pattern periodically changes between a first pattern and a second pattern;
An extension direction of the bright portion and the dark portion in the second pattern is perpendicular to an extension direction of the bright portion and the dark portion in the first pattern.
The method for producing the laminated optical film according to claim 5 . the end region identifying step identifies the end region by acquiring positional information of an end of the first optical film and an end of the second optical film that define both ends of the end region in the width direction based on a detection result of the reflected light.
A method for producing the laminated optical film according to any one of claims 1 to 6. the first optical film is a polarizing film,
The second optical film is a surface protective film.
A method for producing the laminated optical film according to any one of claims 1 to 7. The polarizing film includes a polarizer which is a polyvinyl alcohol-based film, and a protective film which is a cellulose acetate film, a norbornene-based resin film, a polycarbonate-based resin film, or an acrylic resin film and is bonded to the polarizer;
The surface protective film is a polyethylene film, a polypropylene film or a polyester film.
The method for producing the laminated optical film according to claim 8 . The edge region detection step and the printing step are carried out while transporting the laminated optical film in a longitudinal direction using a plurality of transport rollers.
A method for producing the laminated optical film according to any one of claims 1 to 9. In the irradiation step, the illumination light is irradiated onto the laminated optical film located on at least one of the plurality of conveying rollers.
The method for producing the laminated optical film according to claim 10 . In the irradiation step, the illumination light is irradiated onto the laminated optical film located between two adjacent transport rollers among the plurality of transport rollers.
The method for producing the laminated optical film according to claim 10 . an end region detection unit that detects an end region in a width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film;
a printing unit that prints an information code recording information about the laminated optical film in the edge region detected by the edge region detection unit;
Equipped with
The edge region detection unit
a light source unit that irradiates the laminated optical film with illumination light having a stripe pattern in which light areas and dark areas are alternately arranged;
a light detection unit that detects reflected light, which is the illumination light reflected by the laminated optical film;
an edge region specifying unit that specifies the edge region based on a detection result of the reflected light;
having
the first optical film and the second optical film are optically transparent;
Printing device. an end region detection unit that detects an end region in a width direction of a long laminated optical film having a first optical film and a second optical film laminated on the first optical film;
a printing unit that prints an information code recording information about the laminated optical film in the edge region detected by the edge region detection unit;
Equipped with
The edge region detection unit
a light source unit that irradiates the laminated optical film with illumination light having a stripe pattern in which light areas and dark areas are alternately arranged;
a light detection unit that detects reflected light, which is the illumination light reflected by the laminated optical film;
an edge region specifying unit that specifies the edge region based on a detection result of the reflected light;
having
the light source unit is configured such that a width of the bright portion or the dark portion changes periodically, thereby causing the stripe pattern to change periodically into a plurality of patterns;
the edge region specifying unit specifies the edge region based on detection results corresponding to the plurality of patterns.
Printing device. the first optical film is a polarizing film,
The second optical film is a surface protective film.
15. The printing device according to claim 13 or 14. The polarizing film includes a polarizer which is a polyvinyl alcohol-based film, and a protective film which is a cellulose acetate film, a norbornene-based resin film, a polycarbonate-based resin film, or an acrylic resin film and is bonded to the polarizer;
The surface protective film is a polyethylene film, a polypropylene film or a polyester film.
The printing device according to claim 15. A conveying mechanism for conveying the laminated optical film in a longitudinal direction is further provided,
The end region detection unit and the printing unit are arranged along a transport path of the laminated optical film by the transport mechanism.
The printing device according to any one of claims 13 to 16. A printer comprising the printing device according to any one of claims 13 to 17.
Manufacturing equipment for laminated optical films.

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