JP2015166770A - Ultra violet radiation apparatus and method of manufacturing optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the radiation amount of ultraviolet rays by effectively avoiding reduction in reliability and accuracy regarding an optical film such as a pattern phase difference film.SOLUTION: Disclosed is an ultraviolet radiation apparatus which is used for manufacturing an optical film 1 equipped with an optical functional layer 4 made of ultraviolet curable resin. The ultraviolet curable resin has a peak of light quantity distribution only in the wavelength band in which the ultraviolet curable resin efficiently reacts. From a light source 10 in which light quantity is distributed in the neighboring band with this wavelength band as the center, ultraviolet rays are emitted which are used for curing of the ultraviolet curable resin.

Description

  The present invention relates to the production of an optical film such as a pattern retardation film according to a passive three-dimensional image display device.

  In recent years, an image display device that displays a three-dimensional image by a passive method has been provided. Here, FIG. 10 is a schematic view showing a passive type image display apparatus using a liquid crystal display panel. The passive-type image display device sequentially assigns pixels of the liquid crystal display panel that are continuous in the vertical direction or the horizontal direction (vertical direction in the example of FIG. 10) for the right eye and the left eye, respectively. Driving with the image data for the left eye, thereby displaying the image for the right eye and the image for the left eye simultaneously. In addition, a pattern retardation film is arranged on the panel surface (viewer side) of the liquid crystal display panel so that the light emitted from the right-eye pixel and the left-eye pixel is linearly polarized light having different directions for the right-eye and left-eye. Convert to As a result, in the passive method, glasses equipped with corresponding polarizing filters are worn, and a right-eye image and a left-eye image are selectively provided to the viewer's right and left eyes, respectively, and a three-dimensional image is displayed. To do.

  Therefore, in the pattern retardation film, two types of band-like regions in which the slow axis direction (direction in which the refractive index is maximized) are orthogonal to each other are sequentially formed corresponding to the setting of the pixels in the liquid crystal display panel. Here, the slow axis direction of the adjacent band-like regions is usually a combination of +45 degrees and −45 degrees or a combination of 0 degrees and +90 degrees with respect to the horizontal direction. In the example of FIG. 10, the long side direction of the screen is shown as the horizontal direction in accordance with the name in the normal image display apparatus.

  This passive method can also be applied to an image display device having a slow response speed, and can display three-dimensionally with a simple configuration using a pattern retardation film and circularly polarized glasses. In the passive type image display device, a method of sequentially assigning pixels consecutive in the horizontal direction to the right eye and the left eye instead of the vertical direction in the example of FIG. 10 is also employed.

  The pattern phase difference film according to this passive method requires a pattern-like phase difference layer that gives a phase difference to transmitted light corresponding to the allocation of pixels. With respect to this pattern retardation film, Patent Document 1 discloses a method of forming a retardation layer by forming a photo-alignment layer on a glass substrate with controlled orientation regulating force and patterning the alignment of liquid crystals with this photo-alignment layer. Is disclosed. Further, Patent Document 2 discloses a method of forming an alignment layer in which a fine uneven shape is formed on the peripheral side surface of a roll plate by laser irradiation, and the uneven shape is transferred to control the alignment regulating force in a pattern shape. ing.

  Patent Document 3 discloses a configuration in which a photo-alignment film is formed on a long film material, and a liquid crystal is patterned by the alignment regulating force of the photo-alignment film to form a retardation layer, thereby creating a pattern retardation film. Is disclosed. More specifically, in the configuration disclosed in Patent Document 3, after applying a coating liquid of a photo-alignment film on a transparent film material, a photo-alignment film having an alignment regulating force in a stripe shape is created by a polarization exposure technique. To do. In addition, a coating liquid for a retardation layer made of an ultraviolet curable liquid crystal material is applied onto the photo-alignment film, and then the liquid crystal material is aligned by the alignment regulating force of the photo-alignment film, and then irradiated with ultraviolet rays. Curing is performed, thereby forming a retardation layer.

  Conventionally, a light source using a high-pressure mercury lamp, an electrodeless lamp having a spectrum similar to that of the high-pressure mercury lamp, or the like has been used for the irradiation of ultraviolet rays used for curing the retardation layer.

  By the way, when the irradiation amount of the ultraviolet rays by the light source is increased, the adhesion strength of the retardation layer to the alignment film can be increased, and the reliability can be improved. However, when the irradiation amount of ultraviolet rays increases in this way, there is a problem that the retardation layer itself deteriorates and the reliability decreases. Moreover, the transparent film material which is a base material is damaged by heat and reliability is lowered, and further, there is a problem that the production accuracy of the pattern retardation film is remarkably lowered due to heat shrinkage. In the manufacturing process of the conventional pattern retardation film, in order to prevent such damage to the transparent film material due to heat and heat shrinkage, the film material contacting the peripheral side surface is cooled by circulating a cooling liquid inside. Although a film material is wound around the cooling roll to irradiate ultraviolet rays, there is still a problem that is practically insufficient even with this configuration when the irradiation amount of ultraviolet rays is increased.

JP 2005-49865 A JP 2010-152296 A JP 2014-10358 A

  The present invention has been proposed in view of such circumstances, and for optical films such as pattern retardation films, it is possible to effectively avoid a decrease in reliability and accuracy and increase the amount of ultraviolet irradiation. It can be so.

(1) In an ultraviolet irradiation device used for manufacturing an optical film having an optical functional layer made of an ultraviolet curable resin,
Curing of the ultraviolet curable resin from a light source having a peak of light amount distribution only in a wavelength band in which the ultraviolet curable resin reacts efficiently, and in which a light amount is distributed only in a nearby band centered on the wavelength band Inject ultraviolet light for use.

  According to (1), damage to the optical functional layer due to the short wavelength component can be effectively avoided, and thermal damage and thermal shrinkage of the base material due to the long wavelength component can be prevented. As a result, reliability is improved. Therefore, it is possible to effectively avoid the deterioration of accuracy and increase the irradiation amount of ultraviolet rays.

  (2) In (1), the light source is a plurality of light emitting diodes.

  According to (2), the ultraviolet irradiation device can be configured with a more specific configuration.

(3) In (2),
The plurality of light emitting diodes are arranged in a row so as to cross the substrate of the optical film in the width direction,
A plurality of the row-like arrangements are provided in the longitudinal direction of the substrate of the optical film.

  According to (3), it is possible to irradiate ultraviolet rays with a uniform and sufficient light amount distribution.

  (4) In (3), the light emitting diodes are arranged in a staggered manner.

  According to (4), it is possible to irradiate ultraviolet rays with a more uniform light amount distribution.

(5) In the method for producing an optical film having an optical functional layer made of an ultraviolet curable resin,
Curing of the ultraviolet curable resin from a light source having a peak of light amount distribution only in a wavelength band in which the ultraviolet curable resin reacts efficiently, and in which a light amount is distributed only in a nearby band centered on the wavelength band Inject ultraviolet light for use.

  According to (5), damage to the optical functional layer due to the short wavelength component can be effectively avoided, and thermal damage and thermal shrinkage of the substrate due to the long wavelength component can be prevented, and as a result, reliability Therefore, it is possible to effectively avoid the deterioration of accuracy and increase the irradiation amount of ultraviolet rays.

  (6) In (5), the light source is a plurality of light emitting diodes.

  According to (6), the ultraviolet irradiation device can be configured with a more specific configuration.

(7) In (6),
The plurality of light emitting diodes are arranged in a row so as to cross the substrate of the optical film in the width direction,
A plurality of the row-like arrangements are provided in the longitudinal direction of the substrate of the optical film.

  According to (7), it is possible to irradiate ultraviolet rays with a uniform and sufficient light amount distribution.

  (8) In (7), the light emitting diodes are arranged in a staggered manner.

  According to (8), it is possible to irradiate ultraviolet rays with a more uniform light amount distribution.

(9) In (5), (6), (7), or (8),
The optical film is a pattern retardation film,
The optical functional layer is a phase difference layer in which two band-like regions having different phase differences to transmitted light are alternately provided.

  According to (9), regarding the pattern retardation film, it is possible to effectively avoid a decrease in reliability and accuracy, increase the irradiation amount of ultraviolet rays, and increase the adhesion between the alignment film and the retardation layer. .

  ADVANTAGE OF THE INVENTION According to this invention, regarding optical films, such as a pattern phase difference film, the fall of reliability and precision can be avoided effectively and the irradiation amount of an ultraviolet-ray can be increased.

It is a figure where it uses for description of the pattern phase difference film which concerns on 1st Embodiment of this invention. It is a flowchart which shows the manufacturing process of the pattern phase difference film of FIG. It is a figure where it uses for description of the exposure process of the pattern phase difference film of FIG. It is a figure where it uses for description of the other example of the exposure process of the pattern phase difference film of FIG. It is a figure where it uses for description of the example different from the example of FIG.3 and FIG.4 of the exposure process of the pattern phase difference film of FIG. It is a characteristic curve figure which shows the spectrum analysis result of the emitted light of a high pressure mercury lamp. It is a characteristic curve figure which shows the spectrum of the emitted light in the light emitting diode which inject | emits an ultraviolet-ray. It is a figure where it uses for description of arrangement | positioning of a light emitting diode. It is a figure where it uses for description of other arrangement | positioning of a light emitting diode. It is a figure where it uses for description of the three-dimensional image display by a passive system.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
FIG. 1 is a diagram showing a pattern retardation film applied to the image display device according to the first embodiment of the present invention. In the image display device according to the first embodiment, the pixels of the liquid crystal display panel that are continuous in the vertical direction (the left-right direction is the corresponding direction in FIG. 1) sequentially and alternately display the right-eye image. The pixels are assigned to the left-eye pixels for displaying the left-eye image and the left-eye image, and are driven by the right-eye and left-eye image data, respectively. As a result, the image display device alternately divides the display screen into a band-like region for displaying an image for the right eye and a band-like region for displaying an image for the left eye, so that the image for the right eye and the image for the left eye are divided. Display at the same time. In this image display device, a pattern phase difference film 1 is disposed on the panel surface (viewer side surface) of the liquid crystal display panel, and the pattern phase difference film 1 corresponds to light emitted from right-eye and left-eye pixels, respectively. To give the phase difference. Thereby, this image display apparatus displays a desired three-dimensional image by a passive method.

  Here, the pattern retardation film 1 has an orientation layer 3, a retardation layer 4, and a pressure-sensitive adhesive on one surface of a substrate 2 made of a transparent film such as TAC (triacetylcellulose), acrylic, and cycloolefin polymer. A pressure-sensitive adhesive layer 5 and a separator film 6 are sequentially provided. The pattern retardation film 1 is peeled off the separator film 6 to expose the pressure-sensitive adhesive layer 5, and is then attached to the linear polarizing plate according to the liquid crystal display panel by the pressure-sensitive adhesive layer 5. Thereafter, the pattern retardation film is disposed on the panel surface of the image display panel by being attached to the panel surface of the image display panel integrally with the linear polarizing plate. Although various transparent film materials can be widely applied to the base material 2, it is preferable to apply a TAC film material that is excellent in optical isotropy and excellent in optical characteristics. For the pressure-sensitive adhesive layer 5, various pressure-sensitive adhesives used for bonding of this type of optical film, such as an acrylic pressure-sensitive adhesive, can be applied. In this embodiment, the separator film 6 is a transparent film having a small orientation so as not to hinder the inspection of optical characteristics by transmitted light in a subsequent process. More specifically, a polyethylene film, a PET (Polyethylene terephthalate) film, or the like can be applied.

  In the pattern retardation film 1, a retardation layer 4 is formed of a liquid crystal material that is solidified (cured) while maintaining refractive index anisotropy, and the alignment of the liquid crystal material is patterned by the alignment regulating force of the alignment layer 3. To do. In FIG. 1, the orientation of the liquid crystal molecules is exaggerated by an elongated ellipse. By this patterning, the pattern phase difference film 1 is formed in a band shape alternately with the right-eye area A and the left-eye area B sequentially with a certain width corresponding to the pixel assignment in the liquid crystal display panel. A phase difference corresponding to each light emitted from the right-eye pixel and the left-eye pixel is given.

  After the photo-alignment material layer is produced from the photo-alignment material, the pattern retardation film 1 is irradiated with ultraviolet rays by linearly polarized light by a so-called photo-alignment method, and thereby the photo-alignment method is applied. Thus, the alignment layer 3 is formed. Here, the ultraviolet rays applied to the photo-alignment material layer are set so that the direction of polarization differs between the right-eye region (first region) A and the left-eye region (second region) B by 90 degrees. Thus, with respect to the liquid crystal material provided in the retardation layer 4, liquid crystal molecules are aligned in the corresponding directions in the right-eye region A and the left-eye region B, and a phase difference corresponding to transmitted light is given. Although various materials to which the photo-alignment technique can be applied can be applied as the photo-alignment material, in this embodiment, for example, a light dimerization type material is used. The light dimerization type material is described in “M. Schadt, K. Schmitt, V. Kozinkov and V. Chigrinov: Jpn. J. Appl. Phys., 31, 2155 (1992)”, “M. Schadt, H. Seiberle and A. Schuster: Nature, 381, 212 (1996) "can be used.

  Furthermore, in this embodiment, the anti-reflection layer 7 and the protective film 8 are sequentially provided on the other surface of the substrate 2 in the pattern retardation film 1. Here, the antireflection layer 7 has a contrast by reducing the whitishness by applying an antiglare hard coat layer for preventing visibility deterioration due to reflection of external light and a so-called clear antireflection surface material. In this embodiment, transparency is ensured, the reflectance is reduced, and a high-quality image is displayed.

  The protective film 8 is disposed in order to prevent the pattern retardation film 1 from being damaged in the production process, the conveyance process, and the like. In this embodiment, the protective film 8 is made of a transparent and small-orientation film so as not to hinder the inspection of the optical characteristics by transmitted light in a subsequent process. More specifically, a polyethylene film, a PET (Polyethylene terephthalate) film, or the like can be applied.

(Retardation layer)
The retardation layer 4 contains a polymerizable liquid crystal composition. This polymerizable liquid crystal composition can contain an antiblocking agent and the like in addition to a liquid crystal compound exhibiting liquid crystallinity and having a polymerizable functional group in the molecule (hereinafter also referred to as “rod-like compound”).

  The rod-shaped compound has a refractive index anisotropy, and has a function of imparting a desired phase difference by arranging regularly by the alignment regulating force of the alignment layer 3. Examples of the rod-like compound include materials exhibiting a liquid crystal phase such as a nematic phase and a smectic phase, but the nematic phase is easier to arrange regularly than liquid crystal compounds exhibiting other liquid crystal phases. It is more preferable to use the rod-shaped compound shown.

  Specific examples of the rod-shaped compound used in the present embodiment include compounds represented by the following formulas (1) to (16).

〔Manufacturing process〕
FIG. 2 is a flowchart showing manufacturing steps of the pattern retardation film 1. In the manufacturing process of the pattern retardation film 1, the base material 2 is provided by a long film wound around a roll. In the antireflection layer creation process SP 2, the base material 2 is subjected to surface treatment so that the base material 2 is antiglare hard. A coating layer and a low reflection layer are sequentially formed to form the antireflection layer 7. In the low reflection layer, various configurations relating to the antiglare hard coat layer and the low reflection layer can be widely applied. In the manufacturing process, the base material formed with the antireflection layer in this manner is once wound up by a roll and supplied to the next process as a raw material related to the pattern retardation film 1.

  In the manufacturing process, in the subsequent alignment layer creating process SP3 related to the next process, the coating liquid related to the photo-alignment film is applied by a die or the like, and then dried and baked, whereby the photo-alignment material layer is manufactured. Subsequently, in this alignment layer creation step SP3, a photo-alignment layer is formed by irradiating ultraviolet rays in the exposure step. Here, in the exposure process, after selectively exposing the region corresponding to the right-eye region or the left-eye region by irradiating the ultraviolet light with the linearly polarized light using the mask, the ultraviolet light due to the linearly polarized light whose polarization direction is orthogonal to the entire surface. It is executed by irradiating. When the photo-alignment film has a property that can be rewritten by the second polarized light irradiation, the entire surface is irradiated with the linearly polarized ultraviolet light, and then the linearly polarized light whose polarization direction is orthogonal using the mask is used. Alternatively, it can be executed by selectively exposing the area corresponding to the left eye area. In addition, after selectively exposing the region corresponding to the right eye region or the left eye region by irradiation with ultraviolet rays by linearly polarized light using a mask, the mask is arranged at a position shifted by a half pitch, and the left eye region or the right eye region It can also be executed by selectively performing an exposure process on an area corresponding to the area. In this case, both the material that can be rewritten by the second polarized irradiation and the material that cannot be rewritten can be used.

  Subsequently, in the manufacturing step SP4 of the retardation layer, the liquid crystal material coating liquid is applied and dried with a die or the like, and then the liquid crystal material is cured by irradiation with ultraviolet rays, whereby the retardation layer 4 is manufactured. Is done. In the manufacturing process, the protective film 8 is arranged in the subsequent protective film arrangement process SP5. In the subsequent pressure-sensitive adhesive layer creation step SP6, the pressure-sensitive adhesive layer 5 and the separator film 6 are disposed. Further, in the subsequent cutting step SP7, the pattern retardation film 1 is produced by cutting into a desired size. In this manufacturing process, defects, appearance, and the like are inspected in the subsequent inspection process SP8.

  FIG. 3 is a diagram showing details of an exposure process in the case of using a non-rewritable photo-alignment film material. This manufacturing process is performed by irradiating ultraviolet rays (polarized ultraviolet rays) by linearly polarized light through a mask 16 that shields a portion corresponding to the region A for the right eye or the region B for the light eye. In the left eye region B or the right eye region A, the photo-alignment material film is oriented in a desired direction (FIG. 3A). Thereby, this manufacturing process executes the first exposure process. Subsequently, this manufacturing process irradiates the entire surface with ultraviolet rays by linearly polarized light having a polarization direction different from that of the first exposure process by 90 degrees, and thereby the unexposed right-eye area A or left-eye area B in the first exposure process. Then, the photo-alignment material film is oriented in a desired direction in the right-eye region A or the light-eye region B (FIG. 3B). Thus, in this manufacturing process, the alignment layer 3 is produced by sequentially exposing the right eye region A and the left eye region B by two exposure processes.

  FIG. 4 is a diagram showing details of another example of the exposure process when a rewritable photo-alignment film material is used. In this manufacturing process, the entire surface is irradiated with ultraviolet rays by linearly polarized light to align the photo-alignment material film in a desired direction (FIG. 4A). Thereby, this manufacturing process executes the first exposure process. Subsequently, this manufacturing process includes ultraviolet rays (linearly polarized light) whose polarization direction is 90 degrees different from that of the first exposure process through the mask 16 that shields the portion corresponding to the region A for the right eye or the region B for the light eye. By irradiating polarized ultraviolet light), the photo-alignment material film is oriented in a desired direction in the region B for the left eye or the region A for the right eye that is not shielded (FIG. 4B). Thus, in this manufacturing process, the alignment layer 3 is produced by sequentially exposing the right eye region A and the left eye region B by two exposure processes.

  FIG. 5 is a diagram showing the details of the exposure process that can be used when both rewritable and impossible alignment film materials are used. This manufacturing process is performed by irradiating ultraviolet rays (polarized ultraviolet rays) by linearly polarized light through a mask 16 that shields a portion corresponding to the region A for the right eye or the region B for the light eye. In the left eye region B or the right eye region A, the photo-alignment material film is oriented in a desired direction (FIG. 5A). Thereby, this manufacturing process executes the first exposure process. Subsequently, this manufacturing process is shielded by irradiating ultraviolet rays (polarized ultraviolet rays) with linearly polarized light having a polarization direction different by 90 degrees from the first exposure process through the mask 16 arranged at a position shifted by a half pitch. For the left eye region B or the right eye region A, the photo-alignment material film is oriented in a desired direction (FIG. 5B). Thus, in this manufacturing process, the alignment layer 3 is produced by sequentially exposing the right eye region A and the left eye region B by two exposure processes.

[Phase difference layer creation process]
In the retardation layer forming step, a liquid crystal material coating solution is applied and dried with a die or the like, and then the liquid crystal material is cured by irradiation with ultraviolet rays from an ultraviolet irradiation device to form a retardation layer. Here, the retardation layer is an optical functional layer that imparts a desired retardation to transmitted light. In this embodiment, a wavelength at which an ultraviolet light source for curing the liquid crystal material can efficiently cure the liquid crystal material, and the ultraviolet curable resin according to the liquid crystal material reacts efficiently with respect to the amount of incident light. A band with a light intensity distribution peak only in the band (hereinafter referred to as the high-efficiency reaction wavelength band). Is a light source in which the amount of light is distributed only to the side and the short wavelength side), and as a result, a light source in which the amount of light is not distributed to the longer wavelength side and the shorter wavelength side than the neighboring band is applied. Is done.

  That is, FIG. 6 is a characteristic curve diagram showing a spectrum analysis result of emitted light for a high-pressure mercury lamp used in a conventional light source, and shows each spectrum value by the relative light quantity with respect to the peak light quantity. The high-efficiency reaction wavelength band of the ultraviolet curable resin is a wavelength band of 350 nm to 390 nm, and it is difficult to efficiently cure incident light outside this wavelength band. Among incident light outside this wavelength band, if the amount of incident light on the longer wavelength side (wavelength 400 nm or more) is increased from the neighboring band related to this band, the pattern retardation film will damage the substrate due to heat, and further heat shrink Becomes larger. Further, when the amount of incident light having a shorter wavelength (wavelength of 340 nm or less) than this near band is increased, the retardation layer is damaged.

  As shown in FIG. 6, the light emitted from the high-pressure mercury lamp is sufficiently provided with spectrum components having longer and shorter wavelengths than the high-efficiency reaction wavelength band of such an ultraviolet curable resin. In the case where the adhesion strength of the retardation layer to the alignment film is increased by increasing the thickness of the retardation film, the retardation layer itself deteriorates, the transparent film material is damaged by heat, and further, the transparent film material shrinks by heat and the production accuracy is increased. It drops significantly.

  In particular, the damage and heat shrinkage of the substrate due to such heat are remarkable when the thickness of the substrate is reduced to 25 μm or less, and as a result, it is difficult to reduce the thickness of the pattern retardation film.

  However, there is a case where a light source having a light amount distribution peak only in the high-efficiency reaction wavelength band and having a light amount distribution only in a nearby band centering on the high-efficiency reaction wavelength band is applied as in this embodiment. Therefore, it is possible to prevent the damage of the base material and the heat shrinkage due to such heat, and further prevent the retardation layer from deteriorating, and efficiently create the retardation layer. Even when the adhesion between the alignment film and the retardation layer is enhanced by the increase, it is possible to effectively avoid the deterioration of reliability. Further, since the heat generation can be reduced, the retardation layer can be formed by irradiation with ultraviolet rays without using a cooling roll, and the manufacturing equipment can be simplified. In addition, a transparent film material having a thickness of 25 μm or less can be applied to the substrate, and as a result, the thickness of the pattern retardation film can be reduced.

  More specifically, in this embodiment, a light source for ultraviolet irradiation is created using a light emitting diode that emits ultraviolet light. FIG. 7 is a characteristic curve diagram showing a spectrum of light emitted from this type of light emitting diode. According to FIG. 7, it can be seen that there is a peak in the light amount distribution only in the high-efficiency reaction wavelength band, and there is no light amount distribution on the longer wavelength side and the shorter wavelength side than the neighboring band centered on the wavelength band.

  However, in the manufacturing process of the pattern retardation film, the retardation layer is produced by irradiating ultraviolet rays while conveying a long film material, whereas the light emitting diode is a point light source, which makes it uniform over the entire surface of the substrate. It may be difficult to irradiate ultraviolet rays depending on the amount of light. In addition, the amount of light is smaller than that of a high-pressure mercury lamp or the like, and there is a possibility that the amount of ultraviolet light used for irradiation is insufficient.

  Therefore, in this embodiment, a plurality of light emitting diodes are used to form a light source for ultraviolet irradiation, and the plurality of light emitting diodes are sequentially arranged in a direction crossing the long film material in the width direction. In addition, a plurality of rows of the row-like arrangements are provided in the longitudinal direction of the long film material, so that the entire surface of the substrate is irradiated with ultraviolet rays with a uniform amount of light and with a sufficient amount of light.

  FIG. 8 is a diagram showing the arrangement of the light emitting diodes 10 with respect to the base material 2. In this embodiment, the light emitting diodes 10 are sequentially arranged at regular intervals so as to cross the base material 2 in the width direction, so that the light emitting diodes 10 are arranged in a row. Two rows are provided. Further, by reducing the constant interval between the light emitting diodes 10 according to this row arrangement, the variation in the light amount distribution in the width direction of the substrate 2 is sufficiently reduced.

  Instead of densely arranging the light emitting diodes 10 to make the light quantity uniform, as shown in FIG. 9, the arrangement of the continuous rows is arranged in the width direction of the substrate 2 and the arrangement interval of the light emitting diodes 10 is changed. By shifting the distance by 1/2, the light emitting diodes 10 may be arranged in a staggered manner to make the light quantity uniform. In addition to the arrangement of the light emitting diodes 10, for example, various members for controlling the light amount distribution may be arranged on the optical path of the emitted light of the light emitting diodes 10 to further uniform the light amount distribution. Such a member is a light diffusing plate that scatters the emitted light, a lens that expands the beam diameter of the emitted light in the width direction of the substrate 2, or the like.

  According to this embodiment, with respect to the optical functional layer related to the retardation layer of the pattern retardation film, the ultraviolet light source used for curing has a light amount distribution peak only in the wavelength band in which the ultraviolet curable resin reacts efficiently. By applying a light source in which the amount of light is distributed only in the vicinity band centered on the wavelength band, damage to the optical functional layer due to the short wavelength component can be effectively avoided, and the base due to the long wavelength component can be avoided. It is possible to prevent thermal damage and thermal shrinkage of the material, and as a result, it is possible to effectively avoid deterioration of reliability and accuracy and increase the irradiation amount of ultraviolet rays.

[Second Embodiment]
In this embodiment, the pattern retardation film 1 is used as a protective film for the linear polarizing plate to prevent the linear polarizing plate from being damaged in the manufacturing process of the linear polarizing plate and further in the attaching process of the image display panel. For this reason, in this embodiment, in the manufacturing process of the linearly polarizing plate, the linearly polarizing plate is manufactured after the pattern retardation film is attached to the base material of the linearly polarizing plate. In addition, you may make it affix on the linear polarizing plate before cutting | disconnection, and may prevent a damage | wound in a cutting process. This embodiment has the same configuration as that of the first embodiment except that the process for integration with the linearly polarizing plate is different.

  Even when the pattern retardation film is caused to function as a protective film for the linearly polarizing plate as in this embodiment, the same effect as in the first embodiment can be obtained.

[Third Embodiment]
In this embodiment, the ultraviolet irradiation device described above with respect to the first embodiment is applied to the light source used for creating the antireflection layer 7. That is, in this embodiment, an optical functional layer that functions as a hard coat layer is prepared by irradiating with ultraviolet rays after applying and drying a coating liquid of a composition for hard coat layer using an ultraviolet curable resin. The Furthermore, by applying the same UV curable resin, drying, and curing by UV irradiation, an optical functional layer that functions as a low reflection layer is produced, and an antireflection layer is formed by laminating with the hard coat layer and the low reflection layer. Is produced. In this embodiment, the ultraviolet irradiation apparatus described above with respect to the first embodiment is applied to one or both of the ultraviolet irradiation used for forming the hard coat layer and the low reflection layer.

  In this embodiment, the same effects as those of the first embodiment can be obtained even when applied to the curing of the ultraviolet curable resin relating to the hard coat layer and the low reflection layer.

[Other Embodiments]
As mentioned above, although the specific structure suitable for implementation of this invention was explained in full detail, this invention can change the structure of the above-mentioned embodiment variously in the range which does not deviate from the meaning of this invention.

  That is, in the above-described embodiment, the case where the present invention is applied to the production of the pattern retardation film has been described. However, the present invention is not limited thereto, and for example, a quarter retardation plate, a half retardation plate, and an A plate. In an optical film that imparts a desired retardation to transmitted light by a retardation layer, such as a C plate, it can be widely applied when an optical functional layer that functions as the retardation layer is made of an ultraviolet curable resin. . Further, it can be widely applied when producing an optical film provided with an optical functional layer functioning as a hard coat layer and a low reflection layer. In addition, it can be widely applied to the case where an optical functional layer having various optical functions other than such a retardation layer, a hard coat layer, and a low reflection layer is prepared from an ultraviolet curable resin to produce an optical film. .

DESCRIPTION OF SYMBOLS 1 Pattern phase difference film 2 Base material 3 Orientation layer 4 Phase difference layer 5 Adhesive layer 6 Separator film 7 Antireflection layer 8 Protective film 10 Light emitting diode

Claims (9)

In the ultraviolet irradiation device used for the production of an optical film having an optical functional layer made of an ultraviolet curable resin,
Curing of the ultraviolet curable resin from a light source having a peak of light amount distribution only in a wavelength band in which the ultraviolet curable resin reacts efficiently, and in which a light amount is distributed only in a nearby band centered on the wavelength band Ultraviolet irradiation device that emits ultraviolet light for use in. The ultraviolet irradiation device according to claim 1, wherein the light source is a plurality of light emitting diodes. The plurality of light emitting diodes are arranged in a row so as to cross the substrate of the optical film in the width direction,
The ultraviolet irradiation device according to claim 2, wherein a plurality of the row-like arrangements are provided in a longitudinal direction of the base material of the optical film. The ultraviolet irradiation device according to claim 3, wherein the light emitting diodes are arranged in a staggered manner. In the method for producing an optical film having an optical functional layer made of an ultraviolet curable resin,
Curing of the ultraviolet curable resin from a light source having a peak of light amount distribution only in a wavelength band in which the ultraviolet curable resin reacts efficiently, and in which a light amount is distributed only in a nearby band centered on the wavelength band A method for producing an optical film that emits ultraviolet rays for use in the manufacturing process. The method for producing an optical film according to claim 5, wherein the light source is a plurality of light emitting diodes. The plurality of light emitting diodes are arranged in a row so as to cross the substrate of the optical film in the width direction,
The method for producing an optical film according to claim 6, wherein a plurality of the row-like arrangements are provided in a longitudinal direction of the base material of the optical film. The method for producing an optical film according to claim 7, wherein the light emitting diodes are arranged in a staggered manner. The optical film is a pattern retardation film,
The optical functional layer is a retardation layer in which two strip-like regions having different retardations to transmitted light are provided alternately one after the other. The manufacturing method of the optical film of description.

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