JP2014167548A - Method of manufacturing image display device and image display device obtained by the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method capable of manufacturing an image display device excellent in a camera performance in precise and the excellent manufacturing efficiency.SOLUTION: A method of manufacturing an image display device includes the steps of: pasting a polarizer on a picture display panel; cutting the polarizer in predetermined size; and forming a decolorization part in a predetermined part of the polarizer. The cutting step and the decolorization part forming step are consecutively performed while the polarizer is placed in a common stage. Typically, the predetermined part of the polarizer in which the decolorization part is formed corresponds to a camera hole part of an obtained image display device.

Description

  The present invention relates to an image display device manufacturing method and an image display device obtained by the manufacturing method.

  An image display device such as a mobile phone or a notebook personal computer (PC) is usually equipped with a camera. Various studies have been made for the purpose of improving the camera performance of such an image display device (for example, Patent Document 1). However, with the rapid spread of smartphones and touch panel type information processing devices, further improvement in camera performance is desired. Therefore, there is a demand for a method capable of manufacturing an image display device excellent in camera performance with high precision and excellent manufacturing efficiency.

JP 2011-81315 A

  The present invention has been made to solve the above-described conventional problems, and a main object of the present invention is to provide a method capable of manufacturing an image display device excellent in camera performance precisely and with excellent manufacturing efficiency.

  As a result of intensive studies on the cutting of the polarizer and the formation of the decoloring part in a series of manufacturing steps of the image display device, the present inventors have found that the above object can be achieved by adopting the following method, and the present invention is achieved. It came to be completed.

The method for producing an image display device of the present invention includes a step of laminating a polarizer on an image display panel, a step of cutting the polarizer into a predetermined size, a step of forming a decoloring part in a predetermined portion of the polarizer, The cutting step and the decoloring portion forming step are continuously performed in a state where the polarizer is placed on a common stage.
In one embodiment, the stage is an adsorption stage, and the polarizer is subjected to the cutting step and the decoloring part forming step in a state of being aligned and adsorbed.
In one embodiment, the said cutting process and the said decoloring part formation process are performed by irradiating a respectively different laser beam.
In one embodiment, the stage is movable relative to each of the different laser light sources in the XYZ directions.
In one embodiment, the predetermined part in which the decoloring part is formed in the polarizer corresponds to the camera hole part of the obtained image display device.
In one embodiment, after laminating the polarizer on the image display panel, the polarizer is subjected to the cutting step and the decoloring portion forming step.
In one embodiment, after cutting the polarizer and forming a decoloring portion at the predetermined portion, the polarizer is laminated on the image display panel.
According to another aspect of the present invention, an image display device is provided. This image display device is obtained by the above manufacturing method.

  According to the present invention, in a method for manufacturing an image display device including a polarizer having a decoloring section, the cutting process and the decoloring process of the polarizer are continuously performed with the polarizer placed on a common stage. Thus, an image display device having excellent camera performance can be manufactured with high precision and excellent manufacturing efficiency. More specifically, by performing the cutting process and the decoloring process on the same stage, it is possible to move the polarizer with each stage in a state where the alignment of the polarizer is precisely performed on the stage. In addition, if the position of the stage is controlled in a production line (manufacturing apparatus) or a cutting / decoloring apparatus, the polarizer can be aligned automatically and precisely, so that the displacement of the polarizer can be prevented very well. obtain. As a result, the decoloring portion can be formed with extremely precise positional accuracy. Furthermore, compared with the case where only the polarizer is moved, the burden of alignment is remarkably reduced, and as a result, the tact (manufacturing time per image display device) can be remarkably shortened, which is excellent. Manufacturing efficiency can be realized. In addition, since the above-mentioned decoloring part typically functions as a camera hole part, in the obtained image display device, there is no positional deviation between the camera and the decoloring part (camera hole part), and the camera performance is excellent. (Shooting performance) can be realized.

1A and 1B are schematic views illustrating a method for manufacturing an image display device according to an embodiment of the present invention; FIGS. 1A to 1C are schematic perspective views illustrating a polarizer stacking process; (D)-FIG.1 (e) is a schematic sectional drawing explaining the cutting process and decoloring process of a polarizer. FIGS. 2A and 2B are schematic cross-sectional views illustrating a polarizer cutting process and a decoloring process. FIGS. 2A and 2B are schematic views illustrating a method for manufacturing an image display device according to another embodiment of the present invention. 2 (c) to 2 (e) are schematic perspective views for explaining the step of laminating the polarizer.

  An image display device manufacturing method according to an embodiment of the present invention includes a step of laminating a polarizer on an image display panel (hereinafter referred to as a laminating step), and a step of cutting the polarizer into a predetermined size (hereinafter referred to as a cutting step). And a step of forming a decoloring portion in a predetermined portion of the polarizer (hereinafter referred to as a decoloring portion forming step or a decoloring step). In this invention, the said cutting process and decoloring process are continuously performed in the state which mounted the polarizer on the common stage. In one embodiment, a lamination process, a cutting process, and a decoloring process are continuously performed in a so-called inline (hereinafter, an inline form is referred to as Embodiment 1 for convenience). In more detail, in Embodiment 1, after laminating a polarizer on an image display panel, the polarizer is subjected to a cutting step and a decoloring step continuously from the laminating step. In another embodiment, the stacking step, the cutting step, and the decoloring step are performed in separate lines (so-called off-line) (hereinafter, the off-line form is referred to as Embodiment 2 for convenience). Hereinafter, Embodiments 1 and 2 will be described as representative examples of embodiments of the present invention. Needless to say, the present invention is not limited to these Embodiments 1 and 2. For example, Embodiments 1 and 2 may be combined as appropriate, and Embodiments 1 and / or 2 may be combined with operations, materials, and the like well known in the industry.

A. Embodiment 1
FIG. 1 is a schematic diagram for explaining the first embodiment. FIG. 1A to FIG. 1C are schematic perspective views for explaining a polarizer lamination process, and FIG. 1D to FIG. 1E are polarizer cutting and decoloring processes. It is a schematic sectional drawing for demonstrating. As shown in FIG. 1, in this embodiment, a lamination process, a cutting process, and a decoloring process are continuously performed in-line.

A-1. Lamination Step In the lamination step, a polarizer is laminated on one side or both sides of the image display panel 10. In the illustrated example, a polarizer 20 is laminated on one side of the image display panel 10 conveyed on the production line (FIGS. 1A and 1B), and then the image display panel 10 / polarizer 20 The laminated body is further reversed while being conveyed, and the polarizer 30 is laminated on the side opposite to the polarizer 20 of the image display panel 10 (FIG. 1C). The polarizer 30 is a front side (viewing side) polarizer, and the polarizer 20 is a back side polarizer. The polarizer 20 is cut into a predetermined size in advance and laminated on the image display panel 10. The polarizer 30 is appropriately sized to be cut into a desired size by laser irradiation in a cutting step (A-2) described later (for example, a size corresponding to the image display panel, a size slightly protruding from the image display panel). Are stacked. More specifically, due to recent design requirements for image display devices, it is required that the display unit on the viewing side be as small as possible in the peripheral part called a bezel (frame). Therefore, the polarizer 30 serving as the viewer-side polarizer is required to be stacked with very high positional accuracy (for example, an allowable deviation range of 0.02 mm to 0.03 mm). Accordingly, the polarizer 30 is preferably laminated with an appropriate size as described above, and then can be cut to a desired final size with very high accuracy by laser irradiation. On the other hand, since a polarizer having a size smaller than the size of the image display device is originally attached to the back side, strict size accuracy and position accuracy as in the viewing side are not required. Therefore, the polarizer 20 serving as the back-side polarizer can be cut into a final size in advance and stacked. By laminating the polarizer 20 first and then laminating the polarizer 30, an operation such as inversion is not required immediately before the cutting step, so that both the transportability and the positional accuracy in the cutting step are good. Become.

  Examples of the image display panel include a liquid crystal panel and an organic EL panel. Typically, an image display panel is subjected to a laminating process as a single-wafer image display panel that has been separated from a large image display panel (mother glass) into a predetermined size and washed.

  There is no restriction | limiting in particular as a method of laminating | stacking a polarizer on an image display panel, Arbitrary appropriate methods are employ | adopted. Typically, a polarizer is laminated | stacked on an image display panel through an adhesive layer in the state of the polarizing film in which the protective film was laminated | stacked at least on the one side. For example, an adhesive layer and a release liner are provided in this order on the side of the protective film on which the polarizer is not laminated, and the release liner is peeled off from the sheet-like polarizing film punched out to a predetermined size, and one side of the image display device Are laminated by sticking them together via an adhesive layer. Further, it can be similarly bonded to the other surface. In the case of bonding to both surfaces, the bonding is performed so that the absorption axis directions are orthogonal to each other. Bonding of such a polarizing film and an image display panel can be performed using any appropriate apparatus (for example, JP-A-2005-305999).

  The said polarizer is comprised from the resin film containing a dichroic substance, for example, dye | stains a resin film with a dichroic substance, and is obtained by extending | stretching. The polarizer is usually provided in the state of a polarizing film in which a protective film is laminated on at least one side thereof.

  Any appropriate resin can be used as the resin for forming the resin film. Preferably, polyvinyl alcohol resin (hereinafter referred to as “PVA resin”) is used. Examples of the PVA resin include polyvinyl alcohol and ethylene-vinyl alcohol copolymer. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. An ethylene-vinyl alcohol copolymer can be obtained by saponifying an ethylene-vinyl acetate copolymer. The saponification degree of the PVA resin is usually 85 mol% or more and less than 100 mol%, preferably 95.0 mol% to 99.95 mol%, more preferably 99.0 mol% to 99.93 mol%. is there. The saponification degree can be determined according to JIS K 6726-1994. By using a PVA-based resin having such a saponification degree, a polarizer having excellent durability can be obtained. If the degree of saponification is too high, there is a risk of gelation. The resin film may be a resin layer (PVA resin layer) formed on a resin base material. According to such a form, a thin polarizer (for example, 10 micrometers or less) can be obtained.

  The average degree of polymerization of the PVA-based resin can be appropriately selected according to the purpose. The average degree of polymerization is usually 1000 to 10000, preferably 1200 to 4500, more preferably 1500 to 4300. The average degree of polymerization can be determined according to JIS K 6726-1994.

  Examples of the dichroic substance include iodine and organic dyes. These may be used alone or in combination of two or more. Preferably, iodine is used.

  The dyeing with iodine is performed, for example, by immersing the resin film in an iodine aqueous solution. Any appropriate method can be adopted as a stretching method of the stretching treatment. Specifically, free end stretching or fixed end stretching may be used. The stretching direction can also be set as appropriate, and may be, for example, the longitudinal direction of the long resin film or the width direction of the long resin film. The draw ratio is typically 3 to 7 times. The stretching may be performed after the dyeing treatment or may be performed while dyeing. Moreover, you may dye | stain after extending | stretching. If necessary, the resin film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment and the like. For example, by immersing the resin film in water before washing and washing it with water, not only can the dirt on the surface of the resin film and the anti-blocking agent be washed, but also swelling of the resin film to prevent uneven dyeing, etc. Can do.

  The polarizer preferably exhibits absorption dichroism in the wavelength range of 380 nm to 780 nm. The single transmittance (Ts) of the polarizer is preferably 40% or more, more preferably 41% or more, still more preferably 42% or more, and particularly preferably 43% or more. The theoretical upper limit of the single transmittance is 50%, and the practical upper limit is 46%. Further, the single transmittance (Ts) is a Y value measured with a 2 degree visual field (C light source) of JIS Z8701 and corrected for visibility, for example, using a microspectroscopic system (Lambda Vision, LVmicro). Can be measured. The polarization degree of the polarizer is preferably 99.8% or more, more preferably 99.9% or more, and further preferably 99.95% or more.

  The thickness of the polarizer can be set to any appropriate value. The thickness is typically about 1 μm to 80 μm, preferably 30 μm or less. The thinner the thickness, the better the decolorization part can be formed. For example, in laser light irradiation described later, the absorbance per unit film thickness is high, and a decolorized portion can be formed efficiently.

  Examples of the material for forming the protective film include cellulose resins such as diacetyl cellulose and triacetyl cellulose, (meth) acrylic resins, cycloolefin resins, olefin resins such as polypropylene, and ester resins such as polyethylene terephthalate resins. , Polyamide resins, polycarbonate resins, copolymer resins thereof, and the like.

  The surface of the protective film where the polarizer is not laminated may be subjected to a treatment for the purpose of a hard coat layer, antireflection treatment, diffusion or antiglare as a surface treatment layer. For example, the surface treatment layer is preferably a layer having a low moisture permeability for the purpose of improving the humidification durability of the polarizer.

  The thickness of the protective film is preferably 20 μm to 100 μm. The protective film is typically laminated on the polarizer via an adhesive layer (specifically, an adhesive layer or an adhesive layer). The adhesive layer is typically formed of a PVA adhesive. The pressure-sensitive adhesive layer is typically formed of an acrylic pressure-sensitive adhesive.

A-2. Cutting Step Next, the polarizer (in the illustrated example, the polarizer 30 / image display panel 10 / polarizer 20 laminate 100) laminated on the image display panel is subjected to a cutting step. In the cutting step, the polarizer 30 of the laminate 100 on the stage 110 is irradiated with laser light to cut the polarizer 30 into a predetermined size. More specifically, the laminate 100 of the polarizer 30 / image display panel 10 / polarizer 20 is further transported on the line, and supplied to and placed on the stage 110. As shown in FIG. 1D, the stage 110 on which the stacked body 100 is placed is further transported on the production line, moved to a position where it can be irradiated with a laser beam for cutting, and positioned at the position. To be stationary. The image display panel is positioned on the stage as follows: That is, the alignment mark provided on the image display panel or the boundary between the display part of the image display panel and the black matrix is detected by a camera, for example. The amount of deviation from the reference is calculated. Based on the amount of deviation, positioning is performed by moving the stage or by moving the laser light source. Laser light irradiation for cutting the polarizer is performed at the position thus positioned. Here, the stage 110 and the light source 120 for the cutting laser light are relatively movable in the X direction (conveyance direction), the Y direction (direction perpendicular to the conveyance direction in the horizontal plane), and the Z direction (vertical direction). . That is, when irradiating with laser light, the stage 110 may be moved, or the light source 120 may be moved. Considering the conveyance efficiency (as a result, the production efficiency), it is preferable to move the light source 120. As described above, the polarizer 30 can be cut to a desired size by irradiating the laser beam while relatively moving the light source and the stage (substantially, the polarizer 30 on the stage). According to this embodiment, the polarizer is laminated and fixed on the image display panel, and the alignment of the polarizer (substantially the laminate with the image display panel) is precisely performed on the stage. Therefore, it is possible to cut the polarizer with very high accuracy. Further, by laminating the polarizer and then cutting it to the final size, the alignment burden can be significantly reduced as compared with the case of laminating the polarizer that has been cut to the final size in advance. As a result, tact (manufacturing time per image display device) can be remarkably shortened, and extremely excellent manufacturing efficiency can be realized.

  The relative movement of the stage 110 and the light source 120 in the XYZ directions can be realized by any appropriate means. For example, a case where the light source 120 is moved will be briefly described. In this case, a light source (laser light irradiation means) movement control device is provided in the production line (stage transport line). The light source movement control device is typically an X-axis control unit that is a movement and positioning device in the X direction, a Y-axis control unit that is a movement and positioning device in the Y direction, and a movement and positioning device in the Z direction. A Z-axis control unit, and a calculation unit including an electronic computer or the like. The X-axis control unit supports the Y-axis control unit so as to move and position in the X direction. The Y-axis control unit is supported to be moved and positioned in the X direction by the X-axis control unit, and supports the Z-axis control unit to be moved and positioned in the Y direction. The Z-axis control unit is supported so as to be moved and positioned in the XY plane by the Y-axis control unit, and supports the light source to be moved and positioned along the Z direction. The calculation unit is configured to input X-axis in accordance with predetermined processing data (for example, data relating to which position of the polarizer is irradiated with the laser light at what scanning speed, scanning form, irradiation condition, etc.). Outputs a predetermined control command that instructs the control unit, Y-axis control unit, and Z-axis control unit to position the light source and / or in what scanning speed and scanning mode Then, according to the control command, the light source is positioned by the X-axis control unit, the Y-axis control unit, and the Z-axis control unit, and / or the light source is moved in three dimensions.

The laser beam for cutting preferably includes light having a wavelength of 8.5 μm to 11.0 μm, and more preferably includes light having a wavelength of 9.0 μm to 10.0 μm. In one embodiment, the laser beam for cutting has a peak wavelength in the above range. Typical examples of such lasers include carbon dioxide (CO ₂ ) lasers, argon ion lasers, gas lasers including krypton ion lasers, YAG lasers, YLF lasers, YVO4 lasers, solid lasers such as titanium sapphire lasers, fiber lasers, Semiconductor lasers and dye lasers can be mentioned. Preferably, a CO ₂ laser is used. By cutting with such a laser beam, only the polarizer can be cut well without damaging the image display panel (for example, thermal deformation, damage, cracking of the substrate). By using laser light, processing (cutting) with precise positional accuracy is possible, and as a result, damage to the image display panel can be prevented.

The irradiation conditions of the cutting laser light can be set to any appropriate conditions. For example, when a CO ₂ laser is used, the output is preferably 20 W to 50 W. The pulse energy is preferably 1 mJ to 10 mJ. The scanning speed is preferably 10 mm / second to 10000 mm / second, and more preferably 100 mm / second to 1000 mm / second. The repetition frequency can be appropriately set according to the set scanning speed and pulse energy so as to realize an optimum cutting process. The repetition frequency is, for example, 10 kHz to 40 kHz. The number of overlapping pulses is preferably 10-20. The beam shape at the irradiation position of the laser beam can be appropriately set according to the purpose and the desired shape of the decoloring part. The beam shape may be, for example, a circle having a focal diameter (spot diameter) of 50 μm to 150 μm. According to the above conditions, only the polarizer can be satisfactorily cut without damaging the image display panel.

  In one embodiment, stage 110 is an adsorption stage. That is, suction means (for example, a suction port) is provided at any appropriate position of the stage 110, and the object placed on the stage 110 can be suction-fixed. In the present invention, after the laminated body 100 is aligned on the stage and then fixed by suction, the stage 110 and the laminated body 100 can be prevented from being displaced at the time of laser light irradiation. The polarizer 30 can be cut | disconnected and the effect is very big.

A-3. Decoloring Step Next, the laminate 100 from which the polarizer 30 has been cut to a desired final size is subjected to a decoloring step. The decoloring step is performed by irradiating a predetermined position of the polarizer 30 with a laser beam different from the cutting step. In the present invention, the decoloring step is performed in a state where the polarizer 30 (substantially, the laminate 100) is placed on the same stage 110 as the cutting step. More specifically, the stacked body 100 in which the polarizer 30 is cut to a desired final size remains mounted on the stage 110 (in one embodiment, remains adsorbed and fixed), and the stage 110 is It is transported on the production line, moved to a position where it can be irradiated with a laser beam for forming the decoloring part, positioned at that position, and stopped. As shown in FIG. 1E, laser light irradiation for forming a decoloring part at a predetermined position of the polarizer is performed at the position. The positioning of the stage can be performed in the same manner as the cutting process. By performing the cutting process and the decoloring process on the same stage, the polarizer that has been cut into a predetermined final size with high accuracy in the cutting process is precisely aligned on the stage. It becomes possible to move the child to the irradiation position of the laser beam for decolorization. In addition, the light source of the laser beam for decolorization is also mounted with precise alignment on the production line (manufacturing equipment), so if the position of the stage is controlled on the production line, the position of the polarizer automatically and precisely The alignment can be performed, and the positional relationship between the polarizer and the light source of the laser beam for decoloring can be controlled very precisely. As a result, the positional deviation of the polarizer is prevented very well, and even if the bezel on the viewing side is very small, the position and size can be precisely matched to form the decoloring part. Furthermore, compared to the case of moving only the polarizer (substantially the laminate with the image display panel), the burden of alignment is remarkably reduced, and as a result, the tact time can be remarkably shortened. Excellent manufacturing efficiency can be realized.

  In the decoloring step, a predetermined portion of the polarizer 30 of the laminate 100 on the stage 110 is irradiated with a laser beam different from the cutting laser beam, thereby forming a decoloring portion having a predetermined size in the predetermined portion. To do. Similar to the cutting step, the stage 110 and the light source 130 for the laser beam for decolorization are relatively movable in the X direction, the Y direction, and the Z direction. That is, similarly to the cutting step, the stage 110 may be moved or the light source 130 may be moved when the laser beam is irradiated. Considering the conveyance efficiency (as a result, the production efficiency), it is preferable to move the light source 130. As described above, by irradiating the laser beam while relatively moving the light source and the stage (substantially, the polarizer 30 on the stage), a decoloring part having a predetermined size is applied to a predetermined portion of the polarizer 30. Can be formed. In particular, by performing the cutting process and the decoloring process on the same stage, as described above, the positional deviation of the polarizer can be prevented very well, and the position and size can be precisely adjusted even if the bezel on the viewing side is very small. Together, a decoloring part can be formed.

  The laser beam for decolorization preferably includes light having a wavelength of at least 1500 nm. According to the laser beam including such a wavelength, the decolorization part can be formed satisfactorily. The laser light more preferably includes light having a wavelength of 100 pm to 1000 nm, further preferably includes light having a wavelength of 200 nm to 700 nm, and particularly preferably includes light having a wavelength of 250 nm to 600 nm. In one embodiment, the laser beam has a peak wavelength in the above range. According to the laser light including such a wavelength, the decoloring part can be formed while achieving surface uniformity. Specifically, the decoloring part can be formed without damaging (for example, thermal deformation) the polarizer peripheral optical member (for example, the protective film). More specifically, if the laser light has the wavelength as described above, the difference in absorbance between the polarizer and the peripheral optical member becomes large. Accordingly, the polarizer can absorb a large amount of light without the peripheral optical member absorbing a large amount of light, and damage to the peripheral optical member can be prevented. Moreover, a decoloring part can be formed satisfactorily without damaging the polarizer itself. As a result, it is possible to ensure the flatness of the obtained image display device and achieve a good module design. Furthermore, according to the laser beam containing the said wavelength, the decoloring part which has desired characteristics (for example, a transmittance | permeability, an in-plane phase difference, and light absorbency) can be formed.

  Examples of the laser include solid lasers such as YAG laser, YLF laser, YVO4 laser, and titanium sapphire laser, gas lasers including argon ion laser and krypton ion laser, fiber lasers, semiconductor lasers, and dye lasers. Preferably, a solid laser is used.

  As the laser, a short pulse laser (a laser that emits light having a pulse width of 1 nanosecond or less, such as a picosecond laser or a femtosecond laser) is preferably used. In order to suppress thermal damage to the resin film, a pulse width of 500 picoseconds or less (for example, 10 picoseconds to 50 picoseconds) is particularly preferable. By suppressing the thermal damage, it is possible to satisfactorily suppress the melting of the resin (for example, PVA resin) constituting the resin film. Therefore, a decoloring part having no unevenness and extremely excellent uniformity can be obtained, and as a result, distortion of the image of the camera can be prevented. In one embodiment, irradiation with laser light having different wavelengths and / or pulse widths may be combined. The type of laser light to be irradiated and the irradiation order can be appropriately set according to the purpose. For example, by irradiating with a picosecond laser and then with a nanosecond laser, both hue and transparency can be improved as compared with the case of irradiating with a picosecond laser alone. In this case, the nanosecond laser preferably has a shorter wavelength (for example, 400 nm to 460 nm) than the picosecond laser.

  The irradiation condition of the laser beam can be set to any appropriate condition. For example, when a solid laser (YVO4 laser) is used, the pulse energy is preferably 10 μJ to 150 μJ, more preferably 25 μJ to 71 μJ. The scanning speed is preferably 10 mm / second to 10000 mm / second, and more preferably 100 mm / second to 1000 mm / second. The repetition frequency can be appropriately set according to the set scanning speed and pulse energy so as to realize an optimum bleaching state. The repetition frequency is, for example, 100 Hz to 12480 Hz. The scan pitch is preferably 10 μm to 50 μm. The beam shape at the irradiation position of the laser beam can be appropriately set according to the purpose and the desired shape of the decoloring part. The beam shape may be, for example, a circle or a line. Any appropriate means can be adopted as means for setting the beam shape to a predetermined shape. For example, laser irradiation may be performed through a mask having a predetermined opening, or beam shaping may be performed using a diffractive optical element or the like. For example, when the beam shape is circular, the focal diameter (spot diameter) is preferably 50 μm to 60 μm. According to the above conditions, a decoloring part can be formed satisfactorily without damaging the polarizing film peripheral member and the resin film itself. Moreover, the optical characteristic of the decoloring part mentioned later can be achieved favorably.

  Preferably, the laser light includes polarized light that is substantially coaxial with the absorption axis of the polarizer 30. According to such a laser beam, the difference in absorbance between the polarizer and its peripheral optical member can be further increased, and the decolorization part can be formed more satisfactorily.

  In the irradiation, for example, a laser may be scanned and positioned by driving a galvanometer mirror. Further, for the purpose of obtaining the surface uniformity of the decolorized portion, a homogenizer (DOE: Diffractive Optical Element) that uniformizes the laser light intensity mainly having a Gaussian distribution may be used. By adopting such a configuration, it is possible to form a decolorization part with better uniformity.

  In addition, the said decoloring part can be formed favorably, achieving surface uniformity also by irradiating X-rays. In addition to this, for example, the decoloring portion can also be formed by a light source (for example, a Xe lamp) that emits light having a wavelength of 100 pm to 1500 nm, a heating means such as a heating plate for barcode printing, or the like.

  In one embodiment, the decoloring part formed in the polarizer 30 corresponds to the camera hole part of the obtained image display device. The arrangement, shape, size, etc. of the decoloring part can be designed as appropriate. Preferably, it is designed according to the position, shape, size, etc. of the camera hole part of the obtained image display device. Specifically, the decoloring part is formed at a position corresponding to the camera part and the camera hole part of the obtained image display apparatus and not corresponding to the display screen. For example, the decoloring part can be formed at the upper center part of the polarizer 30. In the present invention, as described above, since the decoloring part is formed with extremely precise positional accuracy, there is substantially no positional deviation from the camera, and very excellent camera performance (photographing performance) can be realized.

Birefringence _{R PVA} bleaching portion formed is 0.035 or less, preferably 0.032 or less, more preferably 0.030 or less. The lower limit of the birefringence _{R PVA} bleaching unit is, for example, 0.010. With such a range birefringence R _PVA bleaching unit, not only to impart the desired transparency bleaching unit, in the case of using a bleaching unit as a camera hole portion of the image display device, brightness and color From both viewpoints, it is possible to achieve very good shooting performance. It is presumed that such birefringence can be realized when a complex of a resin (for example, a polyvinyl alcohol-based resin) that constitutes a resin film and iodine in the decolorization part is destroyed at an appropriate ratio. Such birefringence can be realized by using the above laser light and performing irradiation under the above conditions. In addition, birefringence _RPVA is calculated | required by a formula: _RPVA = nx-ny. Here, nx is the refractive index in the direction in which the refractive index in the film plane is maximum (that is, the slow axis direction), and ny is the direction that is orthogonal to the slow axis in the film plane (that is, the fast axis direction). ).

  The transmittance (for example, transmittance measured with light having a wavelength of 550 nm at 23 ° C.) of the decolorized portion to be formed is preferably 46% or more, more preferably 60% or more, still more preferably 75% or more, and particularly preferably 90%. % Or more. With such a transmittance, desired transparency as a decoloring part can be ensured. As a result, when the decoloring part is used as the camera hole part of the image display device, it is possible to prevent an adverse effect on the photographing performance of the camera. By using the laser beam as described above and irradiating under the above conditions, such transmittance can be realized.

  The formed decolorization part has an absorbance at a wavelength of 350 nm of preferably 2.5 or less, more preferably 2.3 or less, and further preferably 2.1 or less. The lower limit of the absorbance is 1.2, for example. When the decoloring part has such absorbance, when the decoloring part is used as the camera hole part of the image display device, it is possible to realize a very excellent photographing performance from the viewpoint of both brightness and color. This effect can be exhibited synergistically with the above-described effect due to birefringence. In the decolorization part, as described above, it is estimated that such an effect is realized by the decomposition of the complex of the PVA resin and iodine at an appropriate ratio. Furthermore, the iodine complex is also in an appropriate ratio. The above-mentioned desired absorbance can be realized by collapsing with, and a synergistic effect can be exhibited. Such absorbance can be realized by irradiating under the conditions as described above using the laser light as described above.

A-4. Other Steps Next, the laminated body 100 in which the decoloring part is formed at a predetermined position of the polarizer 30 is subjected to a so-called module manufacturing process and assembly process. For example, when the image display panel is a liquid crystal panel, the module manufacturing process includes a TAB crimping process and a PCB mounting process, and the assembly process includes a camera incorporating process and a backlight unit incorporating process. As the module manufacturing process and the assembly process, procedures and operations that are well known and used in the industry are adopted, and detailed description thereof is omitted.

  A liquid crystal display device is manufactured as described above.

B. Embodiment 2
As described above, in the present embodiment, the stacking process, the cutting process, and the decoloring process are performed in separate lines (so-called off-line). That is, the viewing-side polarizer is cut and the decoloring part is formed on a line separate from the production line (manufacturing process) including the lamination of the polarizers, the module production, and the assembly, and the image is displayed at any appropriate time on the production line. Laminate on equipment.

  FIG. 2 is a schematic diagram for explaining the second embodiment. FIGS. 2A to 2B are schematic cross-sectional views for explaining a polarizer cutting step and a decoloring step, and FIGS. 2C to 2E are polarizer lamination steps. It is a schematic perspective view for demonstrating. In this embodiment, as shown in FIGS. 2A and 2B, the viewing-side polarizer 30 is subjected to a cutting process and a decoloring process on a line separate from the production line. Here, as in the first embodiment, the decoloring step is performed in a state where the polarizer 30 is placed on the same stage 110 as the cutting step. More specifically, as shown in FIG. 2A, the viewing side polarizer 30 is cut to a desired final size on the stage 110, and the cut viewing side polarizer 30 is placed on the stage 110. The stage 110 is moved to a position where it can be irradiated with laser light for forming the decoloring part, and is positioned and stopped at that position. As shown in FIG. 2B, laser light irradiation for forming a decoloring part at a predetermined position of the polarizer is performed at the position. By performing the cutting process and the decoloring process on the same stage, it is possible to move the polarizer to the irradiation position of the laser beam for decoloring, with the polarizer being precisely aligned on the stage. Become. In addition, since the light source of the laser beam for decolorization is also mounted with precise alignment in the apparatus for cutting and decoloring, if the position of the stage is controlled in the apparatus, the position of the polarizer is automatically and precisely The alignment can be performed, and the positional relationship between the polarizer and the light source of the laser beam for decoloring can be controlled very precisely. As a result, the positional deviation of the polarizer is prevented very well, and even if the bezel on the viewing side is very small, the position and size can be precisely matched to form the decoloring part. Furthermore, compared with the case where only the polarizer is moved, the alignment burden is remarkably reduced, and as a result, the tact time can be remarkably shortened, and very excellent production efficiency can be realized.

  In parallel, as shown in FIG. 2C and FIG. 2D, the back side polarizer 20 is laminated on one side of the image display panel 10 conveyed on the production line. Next, the laminate of the image display panel 10 / back side polarizer 20 is further reversed while being conveyed, and as shown in FIG. 2 (e), on the side opposite to the back side polarizer 20 of the image display panel 10, a predetermined The viewing side polarizer 30 cut to a final size and having a decoloring part formed at a predetermined position is laminated. Next, the laminated body of the viewing side polarizer 30 / image display panel 10 / back side polarizer 20 is subjected to a module manufacturing process and an assembly process.

  The lamination of the viewing side polarizer is performed as follows, for example. In one embodiment, the image display panel 10 is provided with a mark (not shown) that can be recognized from the outside, and the viewing side polarizer 30 is aligned based on the mark and laminated on the image display panel 10. Is done. In another embodiment, the viewing side polarizer 30 is laminated on the image display panel 10 in the following procedure: First, while reading the position (Xp, Yp, θp) of the polarizer with a camera, the surface is A polarizer (in many cases, a polarizing film) is affixed to a drum that has a weak adhesive surface. Next, the image display panel is arranged on the stacking stage, and the position (Xd, Yd, θd) of the image display panel is read by the camera. A deviation between the position of the polarizer and the position of the image display panel is calculated, and the position of the stacking stage is corrected so as to eliminate the deviation. After correcting the position of the stacking stage, the polarizer on the drum is transferred to the image display panel. According to this embodiment, since the position of the stacking stage is corrected based on the position information of the polarizer and the image display panel, correction (positioning) can be performed with higher accuracy than correcting the stacking position of the polarizer. It becomes. Furthermore, since the polarizer is held by the weakly adhesive surface of the drum, there is no fear of displacement. These synergistic effects enable stacking with extremely high positional accuracy.

  Lamination | stacking of the visual recognition side polarizer 30 may be performed before a module manufacturing process as mentioned above, and may be performed after a module manufacturing process. That is, in another aspect of the second embodiment, for example, after performing TAB pressure bonding and PCB mounting, the viewing side polarizer 30 may be laminated on the opposite side of the back side polarizer 20 of the image display panel 10.

  In addition, since detailed operation, conditions, etc. of each process in Embodiment 2 are the same as that of Embodiment 1, detailed description is abbreviate | omitted.

C. Image Display Device The image display device of the present invention is obtained by the manufacturing method as described in the above items A and B. Examples of the image display device include a liquid crystal display device and an organic EL device. Specifically, the liquid crystal display device includes a liquid crystal panel and a polarizer having the decoloring portion disposed on the viewing side of the liquid crystal panel. The organic EL device includes an organic EL panel in which a polarizer having the decoloring part is disposed on the viewing side. A camera is mounted on the image display device, and the decoloring portion of the viewing side polarizer is disposed so as to correspond to the camera hole portion of the image display device. In the present invention, as described above, since the decoloring part is formed with extremely precise positional accuracy, there is substantially no positional deviation between the camera and the decoloring part (camera hole part), and extremely excellent camera performance (shooting) Performance).

  The production method of the present invention is suitably used for production of camera-equipped image display devices (liquid crystal display devices, organic EL devices) such as mobile phones such as smartphones, notebook PCs, and tablet PCs.

DESCRIPTION OF SYMBOLS 10 Image display panel 20, 30 Polarizer 110 Stage 120 Laser light source 130 for cutting 130 Laser light source for decoloring part formation

Claims (8)

A step of laminating a polarizer on the image display panel, a step of cutting the polarizer into a predetermined size, and a step of forming a decoloring part in a predetermined portion of the polarizer,
The cutting step and the decolorization part forming step are continuously performed in a state where the polarizer is placed on a common stage.
Manufacturing method of image display apparatus.   The manufacturing method according to claim 1, wherein the stage is an adsorption stage, and the polarizer is subjected to the cutting step and the decoloring portion forming step in a state of being aligned and adsorbed.   The manufacturing method according to claim 1 or 2, wherein the cutting step and the decolorization part forming step are performed by irradiating different laser beams.   The manufacturing method according to any one of claims 1 to 3, wherein the stage is movable relative to each of the light sources of the different laser beams in the XYZ directions.   The manufacturing method according to any one of claims 1 to 4, wherein a predetermined portion where a decoloring portion is formed in the polarizer corresponds to a camera hole portion of an image display device to be obtained.   The manufacturing method according to claim 1, wherein after the polarizer is laminated on the image display panel, the polarizer is subjected to the cutting step and the decoloring portion forming step.   The manufacturing method according to claim 1, wherein the polarizer is laminated on the image display panel after the polarizer is cut and a decoloring portion is formed in the predetermined portion. An image display device obtained by the manufacturing method according to claim 1.

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