JP2006044075A - Production apparatus for optical component made of resin, production method, and optical component made of resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin-made optical component improved in reflection preventing characteristics by providing a technique which can prevent the unnecessary deformation of a minute uneven part when the minute uneven part is peeled from a master mold. <P>SOLUTION: As a separation mechanism for separating the resin-made optical component from the master mold 36 installed in a molding cavity, a function to peel the optical component from the master mold within a dislocation direction range of ±15° to the arrangement direction in which minute transfer uneven parts 37 are arranged is provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a molding die for a resin optical component in which a plurality of fine irregularities formed at a height and pitch equal to or less than the wavelength of light are formed, and a method for producing the resin optical component using the molding die. The present invention relates to a resin optical component.

For example, a light guide plate of a lighting device called a front light provided on the front side of a reflective liquid crystal panel as a resin optical component in which a large number of fine concaves or convexes on the order of submicron are formed at a pitch less than the wavelength of light An antireflection film (AR coating layer) provided on the substrate can be exemplified.
FIG. 24 is a cross-sectional configuration diagram of a reflective liquid crystal display device provided with a front light having a light guide plate and an antireflection film. The liquid crystal display device 100 shown in this configuration diagram includes a liquid crystal panel 120 and the liquid crystal panel. 120 and a front light 110 disposed on the front side of 120.

The front light 110 includes a flat light guide plate 112 and a rod-shaped light source 113 disposed on the side end surface 112a side of the light guide plate 112. The front light 110 is configured to transmit light emitted from the light source 113. The light is introduced from the side end surface 112a of the light guide plate 112 to the inner side of the light guide plate 112, and the light is reflected by the reflection surface 112c on the upper surface side of the light guide plate 112 to change the light propagation direction. It is comprised so that it can irradiate toward the liquid crystal panel 120 side from the output surface 112b. On the reflection surface 112c of the previous light guide plate 112, a large number of wedge-shaped concave portions (grooves) 115 having a wedge-shaped cross section are formed, and a gentle slope and a steep slope constituting a triangular concave and convex portion are formed. The light is propagated on the inner side of the light guide plate 112 on the slope, and the light can be emitted to the liquid crystal panel 120 side on the steep slope.
In addition, an antireflection film 117 is formed on the emission surface 112b so that light propagating through the light guide plate 112 can be efficiently extracted to the liquid crystal panel 120 side with low reflectance. Further, it is possible to prevent a phenomenon in which reflected light from the reflective liquid crystal panel 120 is reflected and attenuated by the surface of the light guide plate 112. The antireflection film 117 has a surface on which a large number of fine irregularities (projections) of submicron order are formed at a pitch less than the wavelength of light called an AR (Anti-Reflective) grating.

As a conventional method of manufacturing a resin optical component having a fine uneven surface on which a large number of fine uneven portions of submicron order below the wavelength of light are formed, such as the light guide plate 112 and the antireflection film 117 as described above. Has adopted an injection molding method in which a silicon electromolding material such as an optical component material is injected into a cavity space using a Ni electroforming mold in which a concave and convex transfer surface opposite to the fine unevenness forming surface is formed in the cavity space (for example, Patent Documents 1 and 2).
In order to produce the Ni electroforming mold, a master mold having the same concave / convex shape as the outer shape of the resin optical component is used, and Ni is applied to the required thickness by electrolysis on the surface of the master mold, and then released. As a result, an electroforming mold having a concavo-convex shape in which the concavo-convex shape of the master mold surface is opposite to the concavo-convex shape is obtained, and a resin antireflection film having a fine concavo-convex shape is obtained by resin molding. be able to.
JP-A-6-201908 JP 2002-372603 A

  However, in a conventional method for manufacturing a resin optical component using a Ni electroforming mold, if an attempt is made to manufacture a submicron-order resin optical component having a fine convexity or a concave portion on the fine irregularity forming surface, There is a problem in that the accuracy of transferring the concavo-convex shape to the Ni electromold is poor, and therefore the dimensional accuracy of the finally obtained resin optical component is significantly reduced. In addition, there is a problem that the defect rate is high and the production efficiency cannot be improved because the mold release property when the resin injection molded product (resin optical part) is released from the Ni electroforming mold is poor. These problems are more prominent when a resin optical component having an aspect ratio of 1 or more of the fine protrusions or recesses on the fine unevenness forming surface is produced. The height of the part or the depth of the concave part may differ by 10% or more from the target dimension.

As a technique for facilitating the mold release operation after resin molding, a method of applying a mold release agent such as high melting point waxes or silicone oil to the surface of the Ni electromold is known. The operation itself of applying the release agent to the surface one by one is troublesome, and since it is necessary to apply the release agent after molding after several shots, there is a problem that the production efficiency is deteriorated.
Therefore, the present inventors have been studying a technique for ensuring good moldability by providing an inorganic film having good releasability such as SiO ₂ in the mold cavity in place of using the Ni electroforming mold. It has been found that, when a fine concavo-convex portion having a height equal to or smaller than the wavelength of light and having a fine pitch equal to or smaller than the wavelength of light is formed by resin molding using a master mold, the following problem occurs. .

First, when a resin optical component having fine irregularities with a pitch smaller than the wavelength of light is manufactured by a resin molding method, an operation of releasing the resin optical component from the master mold is required. At the time when the fine irregularities of the pitch at the following heights are removed from the master mold, the fine irregularities formed in the fine irregularities for transfer of the master mold come out from the fine irregularities for transfer of the master mold while being deformed. Therefore, it has been found that there is a problem that the shape of the fine irregularities on the submicron order to be manufactured has a high tendency to deform into an irregular shape.
For example, as shown in FIG. 25, a resin optical component 130 composed of a plate-like portion 130A having a fine uneven portion formed on one surface side and a thick portion 130B adjacent thereto is manufactured by resin formation using a master mold, When this is released from the master mold, the molding apparatus is pushed up as shown by arrows at the corners 130a and 130b and the thick wall 130B, which are considered not to affect the appearance of the resin optical component 130. When the resin optical component 130 is peeled off in the direction of the arrow by pushing it up using a pin or a protruding block, a number of fine irregularities 131 formed in alignment in the plate-like portion 130A of the resin optical component 130 obtained in particular. Among them, a plurality of fine convex portions located on the left and right sides of the plate-like portion 130A are deformed into an irregular shape such as a heart shape, and the directions of the deformed portions are scattered. It was found that there is a problem that had. It should be noted that, as shown by the arrows in FIG. 26, the present inventor has the same deformation when trying to release the plurality of positions evenly with respect to the entire circumference of the plate-like portion 130A. Knows.

  This is because the resin optical parts and the master mold are both made of resin, both of which have inevitably bendability, and the fine irregularities on the tip have a height or pitch below the wavelength of light. Thus, since it has an extremely fine shape, at least one of the resin optical component and the master mold inevitably bends and deforms and peels off. Since both of the fine transfer concavo-convex portions of the concavo-convex transfer surface are subjected to an oblique force and are rubbed and peeled off, each convex portion of the heated fine concavo-convex portion immediately after formation is formed on the master-type concavo-convex transfer surface. This is considered to be a result of releasing the mold while being deformed so as to be collapsed by the fine recess.

  The present invention has been made in view of the above circumstances, and in the case of manufacturing a resin optical component having a fine uneven portion having a height below the wavelength of light and a pitch by molding, the fineness when peeling the fine uneven portion from the master mold. It is an object of the present invention to provide an apparatus and a manufacturing method capable of manufacturing a resin optical component having a good antireflection characteristic by providing a technique capable of preventing unnecessary deformation of the uneven portion, and a resin optical component.

  The present invention has been made in view of the above circumstances, and injects a resin optical component having a fine uneven surface formed by molding a light-transmitting resin and forming a plurality of fine uneven portions with a height and a pitch below the wavelength of light. A molding die for molding, a first mother die and a second mother die that define a cavity space for molding a resin optical component having a fine irregularity-formed surface on which a plurality of fine irregularities are formed. A fine transfer concavo-convex portion provided with a mold that can be freely opened and having a concavo-convex shape opposite to the fine concavo-convex portion of the resin optical component formed on at least one inner surface of the first mother die and the second mother die. And a separation mechanism for separating the resin optical component from the master mold has a deviation direction range of ± 15 ° with respect to the arrangement direction of the fine transfer uneven portions. Within the resin optical part The characterized by comprising a function of peeling off from the master mold.

  At the time of mold release, when the fine uneven portion of the resin optical component is extracted from the fine transfer uneven portion of the master mold, at least one or both of the fine transfer uneven portion of the master mold and the fine uneven portion of the resin optical component are mutually Since the mold is released while receiving a deformation force in an oblique direction while rubbing, a deformation portion corresponding to the deformation force is inevitably generated in at least a part of the fine uneven portion of the resin optical component. When these resin optical parts are peeled off from the master mold within a deviation direction range of ± 15 ° along the direction of arrangement of the master type fine transfer uneven parts, It occurs within a deviation direction range of ± 15 ° along the arrangement direction. In other words, in the fine uneven portion of the resin optical component obtained, a resin optical component in which a deformed portion is generated within a deviation direction range of ± 15 ° along the arrangement direction can be obtained. Here, if the deformed portion exists within a deviation direction range of ± 15 ° along the arrangement direction, the obtained resin optical component does not have uneven color appearance. Further, if there is a deformed portion within the above range, the resin optical component will not be fogged. Accordingly, it is possible to obtain a resin optical component having no color unevenness in appearance, no fogging, and good optical characteristics.

The separation mechanism has a function of separating the resin optical component from the master mold in a direction in which the resin optical component is linearly peeled from one side to the other side.
The separation mechanism has a function of separating the resin optical component from the master mold in a direction of linearly peeling the resin optical component from one side to the other side, thereby generating a deformed portion in the fine uneven portion of the resin optical component. Even if it is a case, it can produce | generate along the arrangement direction of a master type | mold fine transfer uneven | corrugated | grooved part. As a result, it is possible to obtain a resin optical component having no appearance color unevenness, no fogging, and good optical characteristics.

The present invention is characterized in that the master mold includes a substrate and a SiO ₂ film formed on the substrate and having the fine unevenness transfer surface.
As the master type of the inorganic material layer, a material made of a SiO ₂ film can be used. If this master mold is used, it is possible to obtain a resin optical component with fewer defective parts than with the conventional mold using Ni electroforming, and the above-described appearance of non-uniform color and cloudiness. It is possible to provide a resin optical part having no defects and having good optical characteristics and having few defects.

The present invention is characterized in that the pitch of the convex portions or concave portions of the fine transfer concavo-convex portion is set in the range of 100 to 300 nm, and the height or depth of the convex portions or concave portions is set in the range of 100 to 300 nm. To do.
If it is a resin optical component having fine irregularities formed from a master mold having fine transfer irregularities of these pitches and heights or depths, it reliably exhibits an anti-reflection effect in the visible light range and is separated. Resin optical parts that can be reliably molded are obtained.

  The present invention molds a resin optical component having a fine uneven surface with a plurality of fine uneven portions formed at a height and a pitch below the wavelength of light by injection molding a light-transmitting resin into a cavity space of a mold. A method of manufacturing a resin optical component, wherein the mold mold defines a cavity space for molding a resin optical component having a fine uneven surface on which a plurality of fine uneven portions are formed. A mother die and a second mother die are provided so that the molds can freely open, and at least one inner surface of the first mother die and the second mother die has an uneven shape opposite to the fine uneven portion of the resin optical component. A resin having a fine uneven portion by injecting a light-transmitting resin into the cavity space portion using a resin mold for molding an optical component provided with a master die made of an inorganic material layer having a fine uneven transfer surface. After forming the optical component, the When separating a fat optical component from the master mold, a resin optical is used so that the peeling direction at the time of mold release is within a deviation direction range of ± 15 ° with respect to the arrangement direction in which the plurality of fine irregularities are arranged. The part is peeled off from the master mold.

When separating the resin optical parts from the master mold, if the fine uneven parts of the resin optical parts are extracted from the fine transfer uneven parts of the master mold, the fine transfer uneven parts of the master mold or the fine uneven parts of the resin optical component Since at least one or both of the parts are released from each other while receiving a deformation force in an oblique direction while rubbing each other, at least a part of the fine uneven portion of the resin optical component necessarily has a deformation portion corresponding to the deformation force. Arise.
When these resin optical parts are peeled off from the master mold within a deviation direction range of ± 15 ° along the direction of arrangement of the master type fine transfer uneven parts, It occurs within a deviation direction range of ± 15 ° along the arrangement direction. In other words, in the fine uneven portion of the resin optical component obtained, a resin optical component in which a deformed portion is generated within a deviation direction range of ± 15 ° along the arrangement direction can be obtained. Here, if the deformed portion exists within a deviation direction range of ± 15 ° along the arrangement direction, the obtained resin optical component does not have uneven color appearance. Further, if there is a deformed portion within the above range, the resin optical component will not be fogged. Accordingly, it is possible to obtain a resin optical component having no color unevenness in appearance, no fogging, and good optical characteristics.

The present invention is characterized in that when the resin optical component is peeled off from the master mold, it is peeled off linearly from one side to the other side.
Even when a deformed portion is generated in the fine uneven portion of the resin optical component by separating the resin optical component from the master mold in a direction in which the resin optical component is linearly peeled from one side to the other side, the master It can be generated along the direction of arrangement of the fine transfer irregularities of the mold. As a result, it is possible to obtain a resin optical component having no appearance color unevenness, no fogging, and good optical characteristics.

The present invention is characterized in that the pitch of convex portions or concave portions of the fine unevenness transfer surface is set in the range of 100 to 300 nm, and the height or depth of the convex portions or concave portions is set in the range of 100 to 300 nm. To do.
If it is a resin optical component having fine irregularities formed from a master mold having fine transfer irregularities of these pitches and heights or depths, it reliably exhibits an anti-reflection effect in the visible light range and is separated. Resin optical parts that can be reliably molded are obtained.

The present invention is a resin-made optical component having a fine uneven surface on which a plurality of fine uneven portions are formed at a height and a pitch below the wavelength of light by injection molding a light-transmitting resin into a cavity space of a mold. In the plurality of fine uneven portions, deformed portions are formed in portions within a range of ± 15 ° with respect to the arrangement direction.
If the deformed portion has a structure that occurs within a deviation direction range of ± 15 ° along the arrangement direction of the fine concavo-convex portions, color unevenness in appearance does not occur in the resin optical component. Further, if there is a deformed portion within the above range, the resin optical component will not be fogged. Therefore, it is possible to provide a resin optical component having no appearance color unevenness, no fogging, and good optical characteristics.

The deformed portion in the fine uneven portion is formed at the time of separation from the forming mold.
As a result, it is possible to provide a resin optical component that has a deformed portion at the time of separation from the molding die and has no optical color unevenness, no fogging, and good optical characteristics.

In the present invention, the planar shape of the convex portion or the concave portion in the fine concavo-convex portion is round, and at least some of the convex portions or concave portions of the plurality of round convex portions or concave portions have a substantially heart shape in plan view. It is deformed, and the concave side or the projection side of the heart-shaped deformed portion of at least some of the convex portions or concave portions is positioned within a range of ± 15 ° with respect to the arrangement axis direction of the convex portions or concave portions. To do.
As the projections or recesses in the fine concavo-convex part, those having a round planar shape can be applied, and these were deformed by the master-type fine transfer concavo-convex part at the time of mold release and transformed into a heart shape in plan view. However, if the deformed part such as the depression side or the protruding side of the heart-shaped deformed part is located within a range of ± 15 ° with respect to the arrangement axis direction of the convex part or the concave part, there is no color unevenness in appearance. It is possible to provide a resin optical component having no optical fog and good optical characteristics.

  In the present invention, the pitch of the projections or recesses is set in the range of 100 to 300 nm, and the height or depth of the projections or recesses is set in the range of 100 to 300 nm. If it is a resin optical part with fine irregularities formed from a master mold with a fine transfer irregularity in the depth, it is made of resin that can reliably exhibit anti-reflection effect in the visible light range and also ensure mold release An optical component is obtained.

  According to the present invention, at the time of mold release, when the fine uneven portion of the resin optical component is extracted from the fine transfer uneven portion of the master mold, at least one of the fine transfer uneven portion of the master mold or the fine uneven portion of the resin optical component Alternatively, both are rubbed against each other and are released while receiving a deformation force in an oblique direction, so that a deformation portion corresponding to the deformation force is inevitably generated in at least a part of the fine uneven portion of the resin optical component. When these resin optical parts are peeled off from the master mold within a deviation direction range of ± 15 ° along the direction of arrangement of the master type fine transfer uneven parts, It occurs within a deviation direction range of ± 15 ° along the arrangement direction. In other words, in the fine uneven portion of the resin optical component obtained, a resin optical component in which a deformed portion is generated within a deviation direction range of ± 15 ° along the arrangement direction can be obtained. Here, if the deformed portion exists within a deviation direction range of ± 15 ° along the arrangement direction, the obtained resin optical component does not have uneven color appearance. Further, if there is a deformed portion within the above range, the resin optical component will not be fogged. Accordingly, it is possible to obtain a resin optical component having no color unevenness in appearance, no fogging, and good optical characteristics.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiments described below.
FIG. 1 is a cross-sectional view showing an embodiment of a liquid crystal display device including a resin optical component manufactured by the method for manufacturing a resin optical component having a fine uneven surface according to the present invention.
The liquid crystal display device 1 of this embodiment includes a reflective liquid crystal panel 20 and a front light (illumination device) 10 disposed on the upper surface side (front surface side) thereof.
The front light 10 includes a substantially flat transparent light guide plate 12 and a light source 13 integrally connected to the side end surface (light incident surface) 12 a side of the light guide plate 12. The light guide plate 12 is made of a light transmissive resin such as acrylic resin or polycarbonate resin, and the lower surface side (the liquid crystal panel 20 side) of the light guide plate 12 emits illumination light from the front light 10. A prism shape having a triangular wave shape in cross section is formed on the upper surface side (the side opposite to the liquid crystal panel 20) in the figure. More specifically, it has a triangular shape in a sectional view including a gentle slope portion 14a formed to be inclined with respect to the emission surface 12b and a steep slope portion 14b formed with a steeper slope angle than the gentle slope portion 14a. A plurality of convex portions 14 are formed in parallel with each other at a predetermined pitch. An antireflection film (resin optical component) 17 is deposited on the surface of the light exit surface 12 b of the light guide plate 12.

The light source 13 disposed on the side end surface 12a side of the light guide plate 12 is a rod-shaped light source provided along the side end surface 12a of the light guide plate 12, and specifically, at both ends of the rod-shaped light guide 13b. Light emitting elements (not shown) each including a white LED (Light Emitting Diode) are disposed. And the light radiate | emitted from the light emitting element can be introduce | transduced into the light-guide plate 12 through the light guide 13b. Thus, by providing the rod-shaped light guide 13b between the light emitting element and the light guide plate 12, the side end face 12a of the light guide plate 12 is uniformly irradiated with light from a light emitting element such as an LED as a point light source. Can do.
The light source 13 can be used without any problem as long as light can be introduced to the side end face 12a side of the light guide plate 12. For example, light emitting elements such as LEDs are arranged along the side end face 12a of the light guide plate 12. The structure or a light emitter using a cold cathode tube may be used. Moreover, the structure by which only one light emitting element was provided in the one end part side of the light guide 13b may be sufficient.

The front light 10 configured as described above is provided on the reflection surface 12c by introducing the light emitted from the light source 13 from the side end surface 12a of the light guide plate 12 to the inside of the light guide plate 12 and propagating the light. By reflecting the light from the steep slope 14b of the convex portion 14, the light propagation direction can be changed, and the light can be emitted from the emission surface 12b to the liquid crystal panel 20 side as illumination light.
The light guide plate 12 of the front light 10 according to the present embodiment is provided with an antireflection film (resin optical component) 17 manufactured by the manufacturing method of the present invention on the emission surface 12b side. On the surface of the prevention film 17, a plurality of submicron-order fine concave portions or convex portions arranged in a lattice shape are arranged in a plurality at a height and a pitch below the wavelength of light.

An example of the structure of the antireflection film 17 will be described below with reference to FIGS. FIG. 2 is a partial perspective view schematically showing the surface shape of the antireflection film 17. FIG. 3 is a partial cross-sectional view of the antireflection film 17 of FIG.
On one surface of the antireflection film 17 (surface on the light guide plate side), a plurality of fine protrusions 17a having a diameter of about 150 to 400 nm (0.15 to 0.4 μm) are arranged in a lattice pattern. The concavo-convex portion 17 </ b> A allows light in a wide wavelength range to be transmitted with high transmittance, thereby preventing reflection. The reason why the reflection of light can be prevented by providing a fine uneven shape on the order of submicron as described above is because the respective convex portions are arranged and formed at a height below the wavelength of the visible region and a repeating pitch. This is because the incident light is not reflected. Of the surface of the antireflection film 17, the surface provided with a large number of such fine protrusions 17a is a fine uneven surface, and the opposite surface is a flat mounting surface 17B. The antireflection film 17 is attached so that the fine concave and convex portion 17 </ b> A is on the light exit surface 12 b side of the light guide plate 12 and the front mounting surface 17 </ b> B is attached to the back side of the light guide plate 12 of the front light 10. Is integrated.

The pitch of the plurality of convex portions 17a formed in alignment in the antireflection film 17 is preferably in the range of 100 to 300 nm (0.1 to 0.3 μm), and the height H of the convex portions 17a is 100 to 300 nm. It is preferable to be in the range of (0.1 to 0.3 μm). This is because when the pitch P of the convex portions 17a exceeds 300 nm, it is difficult to obtain an antireflection effect in the visible light region, and coloring occurs when light is incident on the light guide plate. When P is less than 100 nm, it becomes difficult to form a concavo-convex shape from the viewpoint of the current processing technique when forming a molding master mold. Further, when the height H of the convex portion 17a is less than 100 nm, there is a problem that the antireflection effect is not exhibited and the reflectance is increased, and conversely, when the height H exceeds 300 nm, it is difficult to release the mold.
Further, the aspect ratio of the convex portion 17a (the ratio of the height H to the pitch P of the convex portion 17a) is in a range of 1 or more, and preferably in the range of 1 or more and 2 or less. This is because if the aspect ratio of the convex portion 17a is less than 1, it is difficult to obtain a sufficient antireflection effect.
As the material of the antireflection film 17, a light transmissive resin such as silicon resin, acrylic resin, norbornene resin is used.

  In the light guide plate 12 according to the present invention, the antireflection film 17 is not provided only on the emission surface 12b, and the antireflection film 17 may be formed also on the side end surface 12a on which the light source 13 is disposed. By adopting such a configuration, it is possible to suppress reflection on the side end surface 12a of the light guide plate 12 when light is introduced from the light source 13 (light guide 13b) to the light guide plate 12, and thus the light source utilization efficiency Can be further improved, and the brightness of the front light 10 can be improved. Further, the case where a large number of fine convex portions 17a are provided on the surface opposite to the light guide plate as the antireflection film 17 has been described. However, the structure has a large number of fine concave portions on the order of submicron on the surface on the light guide plate side. May be.

Next, a method for manufacturing the antireflection film 17 having the above structure will be described.
The antireflection film 17 shown in FIGS. 1 to 3 can be manufactured, for example, by an injection molding method using an antireflection film molding die (resin optical component molding die) shown in FIGS. 4 is a cross-sectional view showing a schematic configuration of the anti-reflection film molding die 30, and FIG. 5 is a partially enlarged cross-sectional view showing a part of the master die provided in the anti-reflection film molding die of FIG. is there.
In this form of the antireflection film molding die 30, the first mother mold 30 a and the second mother mold 30 b that define the cavity space 35 for molding the antireflection film 17 can be freely opened (divided). A master die 36 made of an inorganic oxide layer having a fine concavo-convex surface 36a in which a concavo-convex shape opposite to the fine concavo-convex portion 17a of the antireflection film 17 is formed on the inner surface 31a of the first mother die 30a, The inner surface 31b of the second mother die 30b is a flat surface for molding the surface opposite to the surface on which the fine uneven portion 17a of the antireflection film 17 is formed. Further, an injection port 32 for injecting a resin such as a silicon-based material of the antireflection film 17 into the mold is formed at the side ends of the first matrix 30a and the second matrix 30b. Although omitted, the first mother die 30a and the second mother die 30b are configured to be separable.
As the material of the first mother die 30a and the second mother die 30b, ceramics such as a silicon wafer is used.

The fine unevenness forming surface 36a of the master die 36 has a plurality of fine transfer unevenness portions 37 on the order of submicrons, and these fine transfer unevenness portions 37 are arranged vertically and horizontally in a lattice shape in this embodiment. The inner diameter or pitch P2 of each concave portion of the fine transfer concavo-convex portion 37 is 150 to 400 nm (0.15 to 0.4 μm) which is substantially the same size as the diameter or pitch P of the fine convex portion 17a of the antireflection film 17 to be manufactured. ) Range or 100 to 300 nm (0.1 to 0.3 μm).
Further, the depth D of the fine transfer concavo-convex portion 37 of the master die 36 is set to be substantially the same as the height H of the convex portion 17a of the antireflection film 17, for example. Moreover, (the ratio of the pitch P ₂ of the recess of the depth D and the fine transfer uneven portion) aspect ratio of the fine transfer uneven portion 37 of the master mold 36, for example, substantially the same size as the aspect ratio of the projection 17a of the anti-reflection film 17 The range is 1 or more, more preferably 1 or more and 2 or less.

The fine uneven portion 36a of the master mold 36 in this form has a surface free energy of 4 μJ / cm ² or less (40 erg / cm ² or less), preferably 3.5 μJ / cm ² or less (35 erg / cm ² or less). Covered with layer 38. When the surface free energy of the coating layer 38 exceeds 4 μJ / cm ² , the physical bond with the transfer target (resin injection molded product) becomes weak, so that the mold release when releasing the resin injection molded product from the molding die The nature will decline. On the surface of the coating layer 38, the same uneven shape as the fine transfer uneven portion 37 of the master mold 36 is formed. The coating layer 38 is composed of a DLC layer containing fluorine, a silane compound layer having a fluorine structure, and the like. The coating layer 38 has a thickness of, for example, 50 nm or less.
As a method for producing the coating layer 38 as described above, in the case of a DLC layer containing fluorine, it can be formed by sputtering in an atmosphere containing fluorine. In the case of an inclined DLC layer, it can be formed by performing sputtering while changing the fluorine concentration in the atmosphere. In the case of a silane compound layer having a fluorine structure, it can be formed by dip coating.

In order to produce the antireflection film (resin optical component) 17 using the antireflection film molding die 30 having the above configuration, the antireflection film molding die 30 shown in FIG. 4 is set in an injection molding machine. When a resin-injected molded product is formed in the cavity space 35 by injecting a light-transmitting resin such as a silicon-based resin, which is an antireflective film forming material, melted from the injection port 32, a fine transfer uneven shape on the fine unevenness forming surface of the master die 36 is obtained. Since the resin injection molded product to which is transferred is molded, the first mother mold 30a and the second mother mold 30b are opened to open the molding cavity, and the molded article in the cavity is released from the master mold 36. Thus, the target antireflection film 17 is obtained.
The antireflection film 17 to be manufactured in this form has a structure having a thick plate-like support 18 on the side of the antireflection film 17 as shown in FIG. 6, and the mother shown in FIG. Although not shown in the cross-sectional shapes of the molds 30a and 30b and the master mold 36, the cavity space 35 in the mold can be formed so that the support portion 18 made of a thick resin portion on the side where the fine uneven portions are not formed can be molded. The shape is processed.

  Here, in this embodiment, when the molded product is released from the master die 36, the application point of the release force acts on one side of the antireflection film 17 as shown in FIG. The antireflection film 17 is peeled off. That is, although omitted in FIG. 4, the injection molding machine with the antireflection film molding die 30 set therein can be set at a plurality of positions of the gripping portion 18, and in the directions indicated by arrows a, b, c, d, and e in FIG. A protruding block is provided to push up as uniformly as possible, and after molding, the gripping portion 18 is pushed up in the directions of arrows a, b, c, d and e in FIG. The grip 18 is pressed further away from the master die 36, and the antireflection film 17 is sequentially peeled off from the master die 36.

In other words, this operation is performed in the x direction (or the direction of the antireflection film 17) in the antireflection film 17 in which a plurality of fine protrusions 17a are formed in a predetermined pitch vertically and horizontally in the x and y directions as shown in FIG. This is equivalent to sequentially peeling along the y direction in the case where the angle differs by 90 °. Here, when the fine convex portion 17a of the antireflection film 17 comes out of the fine transfer uneven portion of the master die 36, the fine convex portion of the antireflection film 17 is formed on a part of the inner surface of the fine transfer uneven portion 37 as shown in FIG. While the portion 17a inevitably contacts and rubs, a part of the fine convex portion 17a is pulled out while being deformed. Accordingly, deformed portions are formed on the front side and the back side in the drawing direction along a line along the drawing direction of the antireflection film 17 in a part of the plurality of fine convex portions 17a of the antireflection film 17 after the mold release.
However, as described above, the antireflection film 17 formed by pulling out the antireflection film 17 in one direction from the support portion 18 side, for example, the x direction shown in FIG. 8, reflects the light as schematically shown in FIG. When a large number of protrusions 17a are formed vertically and horizontally on one surface side of the anti-reflection film 17, some of the fine protrusions 17c on both sides in the width direction (y direction) on the one surface of the anti-reflection film 17 vary. 9 is deformed into a heart shape in a plan view as shown in FIG. 9, and among the deformed portions of the fine convex portion 17 c in the plan view heart shape, the depression 17 d side is aligned with the drawing direction (front side), and among the deformed portions, It is possible to obtain the antireflection film 17 in a state where the protrusions 17e are aligned in the drawing direction (front side) side. 8 is an example in this form. For example, when the total number of the fine protrusions is uniformly formed into a heart shape in plan view, or about half or several tens of percent. There may be a case where the fine convex portion is formed in a heart shape in a plan view.

  Thus, for example, the antireflection film 17 in which only some of the fine convex portions 17c on both sides are deformed in a heart shape, or the total or several tens of percent of the fine convex portions 17c are in the direction along the x direction. In addition, the antireflection film 17 having a structure in which the deformed portions (the recessed portions 17d or the protrusions 17e) are aligned does not cause a problem as a necessary function of the antireflection film 17. That is, since the fine convex portions 17c having the deformed portions 17d and 17e are aligned, the appearance of the color unevenness does not occur and the antireflection film 17 is not fogged. Therefore, it is possible to obtain the antireflection film 17 with less variation in reflectance and good optical characteristics. Further, if the variation angle is within a range of ± 15 ° with respect to the x direction, the antireflection film 17 having a small variation in reflectance and good optical characteristics can be obtained.

Next, since the antireflection film 17 having the above-described configuration is provided in the front light 10 shown in FIG. 1, when the light propagating through the light guide plate 12 enters the emission surface 12 b in the front light 10. Almost no reflected light is generated, and the liquid crystal panel 20 can be efficiently illuminated. Further, since the reflection on the inner surface side of the emission surface 12b hardly occurs, the whitening phenomenon caused by the light reflected by the emission surface 12b reaching the user is suppressed, and the contrast of the liquid crystal panel 20 is improved and displayed. Quality can be improved.
In addition, when the light reflected by the reflective liquid crystal panel 20 enters the light exit surface 12b of the light guide plate 12, the antireflection film 17 acts effectively, and the liquid crystal panel 20 reflects with high transmittance. Light is transmitted, and as a result, a high-luminance display can be obtained. This is because when the reflected light of the liquid crystal panel 20 is reflected by the exit surface 12b of the light guide plate 12, a part of the display light is lost and the brightness is lowered, and the light guide plate 12 is reflected by the reflection at the exit surface 12b. This is because the display contrast is reduced due to whitening of the light, but the above-described phenomenon can be prevented by providing the light guide plate 12 with the antireflection film 17.

In addition, although the thing of the structure which formed multiple array of the fine convex part as an anti-reflective film was demonstrated until now, the antireflection layer of the shape which formed multiple array of the fine recessed part may be sufficient. As an example, for example, as shown in FIG. 10, a shape in which a plurality of fine concave portions 51 are formed in the top and bottom sides of a resin main body portion 50, which are formed by hollowing out a shape that matches the fine convex portions 17 a of the previous embodiment. The antireflection film 52 can be exemplified. The depth, pitch, and inner diameter of these fine recesses 51 may be formed to be the same size as the height, pitch, and outer diameter of the fine protrusions 17a of the previous form.
Even with this form of the antireflection film 52, it is possible to obtain the same effect as the antireflection film 17 provided with the fine protrusions 17a of the previous form.

A first mother mold and a second mother mold having a master mold having a length of 60 mm and a width of 50 mm made of a SiO ₂ film having fine transfer irregularities with an inner diameter of the recess of 0.23 μm and a pitch of the recesses of 0.24 μm. Set the forming mold consisting of the mold on the injection molding machine and injection mold Arton (manufactured by JSR Co., Ltd.) as the molding resin into the previous cavity at 290 ° C to match the shape of the fine transfer uneven part of the master mold A resin optical component having fine irregularities of the shape was molded into the cavity.
The first mother die and the second mother die are separated to open the cavity, and then the thick support portion (width 50 mm, length 7 mm) shown in FIG. 6 or FIG. ) Was pushed up to release the antireflection film from the master mold.
In the antireflection film obtained by the above steps, an AFM (atomic force microscope) image of the upper left corner corner portion (position from 10 mm from the left end and 10 mm from the upper end) when the antireflection film is viewed in plan view is shown in FIG. The AFM (atomic force microscope) image of the corner at the lower left corner (10 mm from the left end and 50 mm from the upper end) is shown in FIG. 12, and the AFM (atomic force microscope) at the center of the diagonal intersection when the antireflection film is viewed in plan view. The image is shown in FIG. 13, the AFM (atomic force microscope) image of the upper right corner (10 mm from the right end, 10 mm from the upper end), and the lower right corner (at 10 mm from the right end, 50 mm from the upper end) is shown in FIG. AFM (atomic force microscope) images are shown in FIG.

  From these results shown in FIGS. 11 to 15, the anti-reflection film is peeled from one side along the direction in which the fine uneven portions are arranged in a direction (parallel to the x direction) and released. In the antireflection film obtained in this way, many fine convex portions were deformed into a heart shape in plan view, but had fine convex portions in which the dents or protrusions of the deformed portions were aligned along the peeling direction. It was found that an antireflection film was obtained.

"Comparative example"
The molding machine push-up block when the anti-reflection film is released from the master mold, assuming that the molding conditions are the same as the resin material, the first matrix, the second matrix, and the master mold. 8 in addition to the portion corresponding to the support portion shown in FIG. 8, the frame portion in which the fine convex portion at the left corner of the rectangular antireflection film shown in FIG. 8 is not formed and the rectangular antireflection portion shown in FIG. 8. The anti-reflective film was manufactured by pushing up and releasing the frame part where the fine convex part at the right corner of the film was not formed, with a push-up block.
In the obtained antireflection film, an AFM (atomic force microscope) image of an upper left corner corner portion (position 10 mm from the left end and 10 mm from the upper end) when the antireflection film is viewed in plan is shown in FIG. FIG. 17 shows an AFM (atomic force microscope) image (position 10 mm from the left end and 50 mm from the upper end), and FIG. 18 shows an AFM (atomic force microscope) image at the center of the diagonal intersection when the antireflection film is viewed in plan. FIG. 19 shows an AFM (atomic force microscope) image of the upper right corner (the position 10 mm from the right end and 10 mm from the upper end). FIG. 19 shows the AFM (atomic position from the right end 10 mm, the position 50 mm from the upper end). An atomic force microscope) image is shown in FIG.

From these photographs shown in FIGS. 16 to 20, when the three sides of the antireflection film (a total of three sides of the support portion and the left and right frame portions) are pushed up by the pushing block and released from the mold, the direction of the deformed portion is changed to the antireflection film. It was found that there was a large variation in the plane position. This is because when the left and right frame parts of the antireflection film and the support part are combined and pushed up with three blocks, the antireflection film is peeled off from the master mold while being pushed up simultaneously from three directions. Even if the three sides are pushed up at the same time, if the antireflection film made of resin and having flexibility is viewed as a fine uneven part on the order of submicrons, a pulling force acts from one of the three directions at random for each position, As a result of being peeled off from the master type fine transfer concavo-convex part, it is considered that each fine convex part that received a deformation force in a different direction for each position was deformed.
The antireflective film having the structure of this comparative example has a thin color and is unsuitable for a display device.

  Next, with respect to the antireflection film obtained in the previous example and the antireflection film obtained in the comparative example, in-plane 5 points of the antireflection film (the same position as the previous AFM (atomic force microscope) image measurement position) The reflectance was measured.

FIG. 21 shows the measurement result of the antireflection film of the example, and FIG. 22 shows the measurement result of the antireflection film of the comparative example. From the results shown in FIGS. 21 and 22, it is clear that the variation in the reflectance of the antireflection film of the example is small, and the variation in the reflectance of the antireflection film of the comparative example is large.
From this measurement result, the anti-reflection film manufactured by peeling off the master mold along the direction in which the fine projections are aligned with respect to the anti-reflection film at the time of mold release, and the direction of the deformed portions of the fine projections are aligned. It has been clarified that the antireflection film exhibits better reflection characteristics with less variation than the antireflection film in which the direction of the deformed portion is not uniform.

  FIG. 23 shows the results of measuring the relationship between the in-plane peel direction (°) and the in-plane reflectance difference (%) when peeling off the antireflection film from the mold. When the peeling direction in the surface is changed to 3 °, 7 °, 13 °, 15 °, 17 °, 20 °, the reflectance unevenness (average reflectance difference in the surface = average reflectance max-min) Although gradually increasing, if the in-plane reflectance difference (reflectance unevenness) on the vertical axis exceeds 0.5%, it becomes visible to the naked eye as uneven appearance. Therefore, it can be seen that the peeling direction when peeling the antireflection film from the master mold is preferably 15 ° or less (in other words, within ± 15 ° with respect to the x direction in the plan view of FIG. 8).

FIG. 1 is a cross-sectional view showing an embodiment of a liquid crystal display device provided with an antireflection film manufactured by the method for manufacturing a resin optical component having fine uneven surfaces according to the present invention. 2 is a partially enlarged perspective view schematically showing a surface shape of the antireflection film shown in FIG. 3 is a partially enlarged cross-sectional view of the antireflection film shown in FIG. 4 is a cross-sectional view showing a schematic configuration of an antireflection film molding die used for manufacturing the antireflection film shown in FIG. 2 and a master die provided therein. FIG. 5 is a partially enlarged cross-sectional view showing a master die provided in the antireflection film molding die shown in FIG. 4. FIG. 6 is an explanatory view showing a mold release position and a mold release direction when the antireflection film manufactured by the molding mold shown in FIG. 4 is peeled from the master mold. FIG. 7 is an explanatory view showing an example of a peeled state of the fine concavo-convex part and the fine transfer concavo-convex part in a state where the antireflection film according to the present invention is peeled from the master mold. FIG. 8 is an explanatory view showing a state in which the fine uneven portion of the antireflection film according to the present invention is released from the master fine uneven portion. FIG. 9 is an explanatory view of an antireflection film having a fine uneven portion which has been released as shown in FIG. FIG. 10 is a perspective view showing another embodiment of the antireflection film according to the present invention. FIG. 11 is a photograph showing a deformed state of the fine convex portion at the first position of the antireflection film manufactured in the example. FIG. 12 is a photograph showing a deformed state of the fine convex portion at the second position of the antireflection film manufactured in the example. FIG. 13 is a photograph showing a deformed state of the fine convex portion at the third position of the antireflection film manufactured in the example. FIG. 14 is a photograph showing a deformed state of the fine convex portion at the fourth position of the antireflection film manufactured in the example. FIG. 15 is a photograph showing a deformed state of the fine convex portion at the fifth position of the antireflection film manufactured in the example. FIG. 16 is a photograph showing the deformation state of the fine convex portion at the first position of the antireflection film manufactured in the comparative example. FIG. 17 is a photograph showing a deformed state of the fine convex portion at the second position of the antireflection film manufactured in the comparative example. FIG. 18 is a photograph showing a deformed state of the fine convex portion at the third position of the antireflection film manufactured in the comparative example. FIG. 19 is a photograph showing a deformed state of the fine convex portion at the fourth position of the antireflection film manufactured in the comparative example. FIG. 20 is a photograph showing a deformed state of the fine convex portion at the fifth position of the antireflection film manufactured in the comparative example. FIG. 21 is a view showing a variation state of the reflectance of the antireflection film manufactured in the example. FIG. 22 is a diagram showing a variation state of reflectance of an antireflection film manufactured in a comparative example. FIG. 23 is a cross-sectional view of a liquid crystal panel provided with a general front light and an antireflection film. FIG. 24 is a view showing a result of measuring a relationship between an in-plane peeling direction (°) and an in-plane reflectance difference (%) when the antireflection film is peeled from the mold. FIG. 25 is an explanatory view showing a protruding position after forming the antireflection film in the conventional method. FIG. 26 is an explanatory view showing another example of the protruding position after forming the antireflection film in the conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Front light, 17 ... Antireflection film, 17a ... Fine convex part, 17A ... Fine uneven part, 20 ... Liquid crystal panel, 30 ... Antireflection film formation type | mold, 30a ... 1st mother mold, 30b ... 2nd Matrix, 36 ... fine uneven surface, 37 ... fine transfer uneven portion, 17c ... fine convex portion, 17d ... hollow portion, 17e ... projection, 51 ... fine concave portion, 52 ... antireflection film.

Claims (11)

A molding die for injection-molding a resin optical component having a fine concavo-convex forming surface in which a plurality of fine concavo-convex portions are formed at a height and pitch below the wavelength of light by molding a light-transmitting resin,
A first mother die and a second mother die for defining a cavity space for molding a resin optical component having a fine irregularity-formed surface on which a plurality of fine irregularities are formed are provided so that the mold can be opened. There is provided a master mold composed of an inorganic material layer having a fine transfer concavo-convex portion in which a concavo-convex shape opposite to the fine concavo-convex portion of the resin optical component is formed on the inner surface of at least one of the first master die and the second master die. In addition, a separation mechanism for separating the resin optical component from the master mold allows the resin optical component to be placed within the misalignment direction range of ± 15 ° with respect to the arrangement direction of the fine transfer concavo-convex portions. A mold for molding resin optical parts having a fine unevenness-forming surface, which has a function of peeling from a resin.   2. The resin optical according to claim 1, wherein the separation mechanism has a function of separating the resin optical component from the master mold in a direction in which the resin optical component is linearly peeled from one side to the other side. Mold for molding parts. Plastic optical component mold according to claim 1 or 2, wherein the master mold is characterized in that it consists of SiO ₂ film having a fine transfer uneven portion is formed on a substrate and the substrate.   The pitch of the convex part or concave part of the fine transfer concave-convex part is set in a range of 100 to 300 nm, and the height or depth of the convex part or concave part is set in a range of 100 to 300 nm. The resin-made optical component shaping | molding die in any one of -3. Resin optics for molding a resin optical component having a fine uneven surface with a plurality of fine uneven portions formed at a height and pitch below the wavelength of light by injection molding a light-transmitting resin into a cavity space of a mold A method of manufacturing a component,
As the molding die, a first mother die and a second mother die that define a cavity space for molding a resin optical component having a fine irregularity-formed surface on which a plurality of fine irregularities are formed are opened. An inorganic material layer having a fine transfer concavo-convex portion that is freely provided and has a concavo-convex shape opposite to the fine concavo-convex portion of the resin optical component formed on the inner surface of at least one of the first and second mother dies. Using a mold for resin optical parts molding provided with a master mold consisting of
After injecting a light-transmitting resin into the cavity space to form a resin optical component having fine uneven portions, when separating the resin optical component from the master mold, the fine uneven portions of the resin optical component The resin optical component is peeled off from the master mold so that the peeling direction at the time of mold release is within a deviation direction range of ± 15 ° with respect to the arrangement direction in which the resin is arranged. Method.   6. The method for producing a resin optical component according to claim 5, wherein when the resin optical component is peeled off from the master mold, the resin optical component is peeled off in a straight line from one side to the other side. .   The pitch of the convex part or concave part of the fine uneven part of the resin optical component is set in the range of 100 to 300 nm, and the height or depth of the convex part or concave part is set in the range of 100 to 300 nm. The manufacturing method of the resin-made optical components of Claim 5 or 6. A resinous optical component having a fine irregularity-formed surface in which a plurality of fine irregularities are formed at a height and pitch below the wavelength of light by injection molding a light-transmitting resin into a cavity space of a molding die,
A resin optical component, wherein a deformed portion is formed in a portion within a range of ± 15 ° with respect to the arrangement direction in the plurality of fine uneven portions.   The resin optical component, wherein the deformed portion in the fine uneven portion is a hollow in a plan view or a projection type formed at the time of separation from the forming mold.   The planar shape of the convex portion or concave portion in the fine uneven portion is round, and at least some of the convex portions or concave portions of the plurality of round convex portions or concave portions are deformed into a substantially heart shape in plan view. 9. The depression side or projection side of at least a part of the convex portions or concave portions is positioned within a range of ± 15 ° with respect to the arrangement axis direction of the convex portions or concave portions. Or 9. The resin optical component according to 9. The pitch of the convex part or the concave part of the fine uneven part is set in a range of 100 to 300 nm, and the height or depth of the convex part or the concave part is set in a range of 100 to 300 nm. The resinous optical component according to any one of 10.

Images