JP5399833B2 - Optical device and manufacturing method thereof - Google Patents

Description

  The present invention relates to an optical device having a scattering optical film and a method for manufacturing the same.

  Various things are proposed as a scattering plate arrange | positioned between the backlight of a liquid crystal display device, and a liquid crystal display element (for example, patent document 1).

JP 2001-155520 A

  An object of the present invention is to provide an optical device having a novel optical film having scattering properties and a method for manufacturing the same.

According to one aspect of the present invention, a first substrate that has been subjected to an alignment process in a first direction, and a liquid crystal material formed on the first substrate, the liquid crystal is aligned in the first direction. It has a refractive index greater refractive index anisotropy, the pitch and the depth of the grooves along the length direction of the groove in one direction has a irregularly shaped groove structure not constant, the incident light a first optical film to grant diffuse-scattering property, the first optical device having a polarizing plate parallel to the transmission axis direction is arranged and the direction are provided.

  The optical film can emit the polarized light component in the first direction having a large refractive index more strongly than the polarized light component in the direction intersecting the first direction in the film surface, and can scatter incident light. .

1A to 1D are schematic cross-sectional views illustrating main manufacturing steps of an optical film according to an embodiment of the present invention. FIG. 2A is a schematic plan view of a substrate showing rubbing directions of two types of samples, and FIG. 2B is a schematic plan view showing a stamper substrate. 3A is a polarization micrograph of the optical film of the example, FIG. 3B is a graph showing a schematic cross-sectional shape of the optical film of the example, FIG. 3C is a schematic plan view showing a groove parallel sample, FIG. 3D is a schematic plan view showing a groove orthogonal sample. FIG. 4 is a schematic cross-sectional view showing the measurement system of the first experiment. FIG. 5 is a graph showing the light transmittance of the groove parallel sample of the first experiment. FIG. 6 is a graph showing the light transmittance of the groove orthogonal sample of the first experiment. FIG. 7 is a schematic cross-sectional view showing the measurement system of the second experiment. FIG. 8 is a graph showing the light transmittance at 10 ° incidence of the groove parallel sample of the second experiment. FIG. 9 is a graph showing the light transmittance at 10 ° incidence of the groove orthogonal sample of the second experiment. FIG. 10 is a graph showing the light transmittance at 20 ° incidence of the groove parallel sample of the second experiment. FIG. 11 is a graph showing the light transmittance at 20 ° incidence of the groove orthogonal sample of the second experiment. FIG. 12 is a schematic cross-sectional view of the liquid crystal display device of the example. FIG. 13 is a schematic perspective view showing the multilayer scattering plate of the third experiment. FIG. 14 is a graph showing light transmittance at normal incidence in the third experiment. FIG. 15 is a graph showing the light transmittance at 10 ° incidence in the third experiment. FIG. 16 is a graph showing the light transmittance at 20 ° incidence in the third experiment.

  First, with reference to FIGS. 1-3, the manufacturing method of the optical film by the Example of this invention is demonstrated.

  1A to 1D are schematic cross-sectional views showing main manufacturing steps of the optical film of the example. First, a flat transparent substrate 1a was prepared. The transparent substrate 1a is, for example, a glass substrate. As an example, soda lime glass (blue plate glass) having a thickness of 0.7 mmt was used. In addition, alkali-free glass (white plate glass) can also be used.

  The surface of the transparent substrate 1a was cleaned. For example, plasma cleaning or ultraviolet and infrared cleaning can be used after pure water cleaning or detergent cleaning.

  Then, an alignment film material (for example, Nissan Chemical SE-410) was placed in a predetermined shape on the transparent substrate 1a by flexographic printing, and baked at 180 ° C. for 1 hour to form an alignment film 1b. The alignment film 1b was rubbed with a rubbing machine. Two types of samples with different rubbing directions were prepared. The transparent substrate 1a and the alignment film 1b are collectively referred to as the substrate 1 (which has been subjected to alignment treatment).

  FIG. 2A is a schematic plan view of the substrate 1 showing rubbing directions of two types of samples. The rubbing direction of the first sample is set in a direction parallel to the groove direction with respect to the length direction of the groove to be formed in the optical film later (this may also be referred to as the groove direction), and the second sample is The rubbing direction is set in a direction orthogonal to the groove direction. The first sample is referred to as a groove parallel sample, and the second sample is referred to as a groove orthogonal sample.

  As shown in FIG. 1A, an ultraviolet curable liquid crystal material is dropped by a dispenser 100 on an alignment film 1b of a substrate 1 to form a liquid crystal material film 2a (the liquid crystal material film 2a is subjected to processing described later to form an optical film). 2). As the ultraviolet curable liquid crystal material, a material obtained by adding 0.1 wt% to 0.5 wt% of a reaction initiator to UCL-001 (Δn = 0.152) manufactured by DIC was used.

  The reaction initiator is not particularly limited as long as it is a material sensitive to ultraviolet rays (around 365 nm). In the examples, Irgacure 819 manufactured by Ciba Chemicals was used. The liquid crystal material is preferably sufficiently degassed before use. In the examples, the liquid crystal material was left in a 10 Pa chamber for 5 minutes to 1 hour.

  By forming on the alignment film 1b, the alignment of the liquid crystal molecules in the liquid crystal material film 2a is aligned in the rubbing direction. Thereby, in the plane of the optical film 2, refractive index anisotropy is imparted so that the refractive index in the rubbing direction is increased.

  FIG. 2B is a schematic plan view showing the stamper substrate 3. The stamper substrate 3 has an uneven structure on the surface. As the stamper substrate 3, a copper plate having a groove formed on the surface with a cutting tool was used. While cutting the asymmetric cutting tool at the tip and changing the depth depending on the location, the length direction is almost uniform, but the pitch and depth are not constant, but there are many grooves distributed in a predetermined range. Formed. In the examples, grooves having a pitch distributed in the range of about 3 μm to 6 μm and a depth distributed in the range of about 1 μm to 4 μm (average pitch 4.5 μm, average depth 3 μm) were formed.

  A release agent was coated on the stamper substrate 3 by a spray method. The release agent was coated and allowed to stand for about 8 hours, followed by heat treatment at 60 ° C. for 1 hour. The stamper substrate 3 was not subjected to alignment treatment.

  Next, as shown in FIG. 1B, the substrate 1 was superimposed on the stamper substrate 3 and pressed, and the concavo-convex structure of the stamper substrate 3 was transferred to the surface of the liquid crystal material film 2a to form the optical film 2. The stamper substrate 3 was sufficiently pressed so that the top portion of the concavo-convex structure was in contact with the substrate 1. In the groove parallel sample, the stacking was performed so that the groove direction of the stamper substrate 3 and the rubbing direction were parallel, and in the groove orthogonal sample, the groove direction of the stamper substrate 3 and the rubbing direction were orthogonal.

  The overlapping and pressing of the substrate 1 and the stamper substrate 3 were performed in a vacuum with a degree of vacuum of 10 Pa. It should be noted that the degree of vacuum can be further reduced as long as air mixing is avoided. Implementation in the atmosphere is also possible. In the atmosphere, for example, after both substrates are placed in a temporary press state, the part containing air observed from the transparent substrate side is individually pressed to drive the air out of the substrate and then press It is good to do.

  It is ideal that the liquid crystal material is dripped onto the substrate 1 in an amount necessary for forming the optical film, but it may be overflowed from both ends of the groove of the stamper substrate 3 even if it is somewhat larger. . The overflowing liquid crystal material may be collected and reused.

Next, as shown in FIG. 1C, both substrates 1 and 3 were returned to the atmosphere in a pressed state, and the entire surface of the substrate was irradiated with ultraviolet rays 4 from the transparent substrate 1 side. Irradiation conditions of ² J / cm ² or more were set for a wavelength of 365 nm. The irradiation intensity is desirably 30 mW / cm ² or more. The ultraviolet curable liquid crystal material in the optical film 2 is polymerized by the ultraviolet irradiation.

  Next, as shown in FIG. 1D, the stamper substrate 3 was peeled from the optical film 2. Rather than applying force to one side of the substrate 1 and the stamper substrate 3 and peeling off gradually, force is applied to each side of both substrates, and the entire surface is peeled off simultaneously by pressing at once. By doing so, it can be removed cleanly. Thus, the optical film of the groove | channel parallel sample and groove | channel orthogonal sample of an Example was produced. The substrate 1 and the optical film 2 may be collectively referred to as a scattering plate 5.

  It is not necessary to perform the coding process of the release agent on the stamper substrate for each transfer / peeling. With the material of the example, the transfer / peeling could be performed about 10 times with one release agent coding process. In addition, you may perform coating, such as a triazine coating, on a stamper board | substrate, without using a mold release agent. In this case, it can withstand tens of thousands of press processes, but the coating process is expensive.

  In addition, although copper was shown as an example of a hard material as a stamper board | substrate material, flexible materials, such as a film and a plastic, can also be used. Further, a similar optical film could be formed by using a stamper substrate prepared by reversing and transferring a concavo-convex structure on a film from a base substrate made of copper, which is a hard material.

  In the case of a flexible stamper substrate using a film, the pressing process can also be performed by a laminator, so that the work becomes easier than a hard stamper substrate. Moreover, even if it peels off from the one substrate side by peeling after ultraviolet treatment, it can peel off neatly. Furthermore, it is possible to irradiate ultraviolet rays from the stamper substrate side.

  When using a laminator-bonding press process, there is almost no air bubbles in the transferred concavo-convex shape, so there is no need to operate the entire press processing device in a high vacuum environment and production with simple equipment. Is possible. The reason why the generation of bubbles is small in the laminating and pressing process is considered to be that the air remaining in the mold gradually moves to the outside as the film material is filled into the mold by the sequential pressurizing operation by the laminator. In the press working using a hard die, such an effect cannot be obtained because the pressing operation is performed on the entire surface.

  In addition, although glass was shown as an example of a hard material as a transparent substrate material, flexible materials, such as a film and a plastic, can also be used. Also in this case, since the press work can be realized by the bonding process using a laminator, the work becomes easier than the press process using a hard stamper substrate. Further, in the stamper substrate peeling step after the ultraviolet treatment, when the transparent substrate is also made of a flexible material, it can be more easily peeled off even if it is gradually peeled off from one side of the substrate.

  The ultraviolet curable liquid crystal material suitable for forming the optical film is not limited to UCL-001 made by DIC. Other than that, an ultraviolet curable liquid crystal material having a liquid crystal molecule shape that is long in one direction and having a refractive index in the major axis direction larger than that in the orthogonal direction (Δn> 0) can be used.

  In addition, although the dispenser system was illustrated as a formation method of an optical film, you may use printing systems, such as an inkjet and a flexo, a slit coat, a spray coat, a wire bar coat system. Of course, spin coating can be applied, but other methods are preferable from the viewpoint of material use efficiency.

  Although the dropping method has been exemplified as a method for forming the optical film, a capillary phenomenon may be used. In particular, in the case of a stripe-shaped groove as in the embodiment, the liquid crystal material can be put into the groove from one end of the groove in a state where both substrates are completely overlapped. An uneven structure is formed by forming an optical film along the groove surface.

  Although the pressure may be reduced from the other end side of the groove, the liquid crystal material permeates into the groove due to a capillary phenomenon without particularly reducing the pressure, so that it can be easily sealed. Although a vacuum injection method can also be used, a large amount of liquid crystal material is required with respect to the amount of sealing, such as requiring a step of immersing the substrate in the liquid crystal material in a vacuum chamber (use efficiency is low), and in the groove In order to maintain the degree of vacuum and air tightness, it is necessary to take care that a seal must be formed around both substrates.

  FIG. 3A is a polarization micrograph of the optical film of the example. The magnification is 50 times. An irregular concavo-convex structure (a groove structure in which the length direction is substantially aligned in one direction but the pitch and depth are not constant) transferred from the stamper is formed on the optical film surface. When the polarizing plate was fixed and the optical film was rotated and observed, the brightness changed depending on the rotation angle, and it was found that the desired refractive index anisotropy was imparted.

  FIG. 3B is a graph illustrating a schematic cross-sectional shape of the optical film of the example. The cross-sectional shape was measured with a stylus type step gauge (Dicktack). The pitch of the grooves (distance between vertices of adjacent convex portions in the direction orthogonal to the length direction of the grooves) was distributed in the range of 3 μm to 6 μm. In addition, since the stylus stylus is thick, an accurate value for the depth could not be obtained.

  FIG. 3C is a schematic plan view showing a groove parallel sample. In the groove parallel sample, the groove direction (solid arrow direction) and the direction in which the refractive index is large (broken arrow direction) are parallel.

  FIG. 3D is a schematic plan view showing a groove orthogonal sample. In the groove orthogonal sample, the groove direction (solid arrow direction) and the direction with a large refractive index (broken arrow direction) are orthogonal to each other.

  Next, with reference to FIGS. 4-11, the 1st and 2nd experiment which measured the light transmittance of a groove | channel parallel sample and a groove | channel orthogonal sample is demonstrated.

  FIG. 4 is a schematic cross-sectional view showing the measurement system of the first experiment. A polarizing plate 6 is disposed above the optical film 2 formed on the substrate 1 in parallel with the substrate 1, a light receiver 11 is disposed above the polarizing plate 6, and a projector 10 is disposed below the substrate 1. Has been.

  The light projector 10 emits light traveling in one direction, and the light projector 10 is arranged so that the light emitted from the light projector 10 enters from the normal direction of the substrate 1. The light incident on the substrate 1 is scattered by the concavo-convex structure of the optical film 2, and a part of the scattered light passes through the polarizing plate 6 and is measured by the light receiver 11. The normal direction of the substrate 1 is set to 0 °, and the receiver angle (viewing angle) is changed within a plane orthogonal to the groove direction of the optical film 2. The light transmittance at various receiver angles was measured.

  For each of the groove parallel sample and the groove orthogonal sample, an arrangement in which the transmission axis of the polarizing plate 6 is parallel to the groove direction (this is referred to as a polarizing plate parallel arrangement), and the transmission axis of the polarizing plate 6 is the groove direction. And (on a plan view) an orthogonal arrangement (hereinafter referred to as a polarizing plate orthogonal arrangement) was measured.

  5 and 6 are graphs showing the light transmittances of the groove parallel sample and the groove orthogonal sample, respectively. The horizontal axis shows the receiver angle in degrees, and the vertical axis shows the light transmittance in%. In addition, the total light quantity when there is no scattering plate 5 and polarizing plate 6 is set to 100% light transmittance. A white C light source was used as the light source of the projector.

  As shown in FIG. 5, in the groove parallel sample, there is a tendency that the parallel arrangement of the polarizing plates tends to have a higher light transmittance over the entire range of the receiver angle of 0 ° to 50 °, compared to the orthogonal arrangement of the polarizing plates.

  On the other hand, as shown in FIG. 6, in the groove orthogonal sample, the polarizing plate orthogonal arrangement tends to have a higher light transmittance in the entire range of the receiver angle of 0 ° to 50 ° than the polarizing plate parallel arrangement. It is done.

  From these experiments, even if the polarizing plate transmission axis direction is parallel or orthogonal to the groove direction, when the polarizing plate transmission axis direction is aligned with the direction in which the refractive index of the optical film is large, a high transmittance is obtained. It can be said that it is obtained. In other words, the optical films of the examples are considered to have a function of emitting a polarized light component in a direction with a large refractive index within the film surface more strongly than a polarized light component in a direction with a small refractive index.

  The light emitted from the projector is incident on the optical film and is irregularly reflected / scattered by the concavo-convex structure, but the polarization component parallel to the direction in which the refractive index is large within the optical film surface is likely to escape upward, and the direction in which the refractive index is small. It is estimated that the polarized light component parallel to is difficult to escape upward by reflection or being guided inside the optical film.

  When the transmission axis direction of the polarizing plate is aligned with the direction in which the refractive index of the optical film is large, the light transmission amount (integrated value with respect to the angle of the light receiver) is A, and the transmission axis direction of the polarizing plate is the direction in which the refractive index of the optical film is small. And B is the light transmission amount (integral value with respect to the receiver angle). (A−B) / B is defined as a difference in brightness. In the first experiment, the difference in brightness was about 15% to 16% for both the groove parallel sample and the groove orthogonal sample, which was about the same for both samples.

  Note that it is considered that the difference in brightness can be increased by increasing the refractive index anisotropy in the optical film plane. In order to increase the refractive index anisotropy, another liquid crystal material may be mixed with the ultraviolet curable liquid crystal material. It has been confirmed that, for the exemplified ultraviolet curable liquid crystal material UCL-001, a solid film can be obtained up to about 50 wt% even if other liquid crystal materials are added.

  FIG. 7 is a schematic cross-sectional view showing the measurement system of the second experiment. Differences from the measurement system of the first experiment will be described. In the second experiment, the substrate normal direction was set to 0 °, the projector angle (incident angle) was changed in a plane orthogonal to the groove direction, and the light transmittance was measured when the light ray was obliquely incident on the scattering plate. .

  8 and 9 are graphs showing the light transmittances of the groove parallel sample and the groove orthogonal sample, respectively, at an incident angle of 10 °.

  10 and 11 are graphs showing the light transmittances of the groove parallel sample and the groove orthogonal sample when the incident angle is 20 °.

  As in the case of the first experiment (incident angle 0 °), for each of the groove parallel sample and the groove orthogonal sample, the polarizing plate parallel arrangement with the polarizing plate transmission axis parallel to the groove direction, and the polarizing plate transmission axis Measurement was performed on the orthogonal arrangement of the polarizing plates orthogonal to the groove direction.

  As shown in FIGS. 8 to 11, in the groove parallel sample and the groove orthogonal sample, the polarizing plate transmission axis direction is the direction in which the refractive index of the optical film is large, as in the first experiment, at both the incident angles of 10 ° and 20 °. When it is aligned, high transmittance is obtained.

  However, in the second experiment with oblique incidence, the groove parallel sample tends to have a larger brightness difference than the groove orthogonal sample. In particular, when the incident angle is 20 °, the difference in brightness of the groove parallel sample is about 20%, whereas the difference in brightness of the groove orthogonal sample is about 14%. This suggests that by aligning the groove direction of the optical film and the direction having a large refractive index within the film surface, the light transmission amount of the polarization component in the direction having the large refractive index can be increased.

  In addition, in the second experiment with oblique incidence, in the groove parallel sample and the groove orthogonal sample, there is a tendency that the peak of the light transmittance distribution is located at an angle smaller than the incident angle in both the polarizing plate parallel arrangement and the polarizing plate orthogonal arrangement. It is done. That is, a lot of light can be emitted upward (in the normal direction of the substrate).

  From the first and second experiments, it was found that the amount of light transmitted through the optical film (integrated value for the receiver angle) tends to increase as the incident angle increases. For example, in the case of parallel arrangement of polarizing plates in a groove parallel sample, the light transmission amount was about 1.5 times at an incident angle of 20 ° compared to an incident angle of 0 °.

  The optical film of the embodiment spreads the traveling direction of light in a direction perpendicular to the groove direction due to the groove structure. For example, incident light from a linear light source that is long in one direction parallel to the groove direction can be scattered to obtain outgoing light like a planar light source whose light intensity is made close to uniform in the plane.

  Next, with reference to FIG. 12, the liquid crystal display device of an Example is demonstrated. FIG. 12 is a schematic cross-sectional view of the liquid crystal display device of the example. The liquid crystal display device according to the embodiment includes a backlight 20, a scattering plate 21, and a liquid crystal display element 22. The backlight 20 has, for example, a direct type structure, but can also have a side light type structure. The liquid crystal display element 22 includes, for example, a pair of polarizing plates 22a and 22c arranged in crossed Nicols, and a liquid crystal cell 22b sandwiched between the polarizing plates 22a and 22c.

  The scattering plate 21 includes the optical film of the embodiment and its substrate, and is disposed between the backlight 20 and the backlight-side polarizing plate 22 a of the liquid crystal display element 22. The direction in which the refractive index is large in the film surface of the optical film of the scattering plate 21 and the transmission axis direction of the backlight side polarizing plate 22a are aligned.

  With such an arrangement of the scattering plate 21 and the backlight side polarizing plate 22a, the amount of light transmitted through the backlight side polarizing plate 22a can be increased, and the light intensity can be made uniform in the plane.

  As described above, the light emitted from the linear light source can be spread in a planar shape by using one optical film of the embodiment. In order to spread the light emitted from the point light source in a planar shape, it is considered preferable to use two optical films of the embodiment with the groove directions intersecting each other. The first optical film spreads the light from the point light source as a linear light source, and the second optical film further spreads the light spread as a linear light source like a planar light source.

  Next, a third experiment in which the light transmittance of a two-layered scattering plate is measured will be described with reference to FIGS.

  FIG. 13 is a schematic perspective view showing the laminated structure of the scattering plates of the third experiment. In the third experiment, from the light incident side, the groove parallel sample 30 and the groove orthogonal sample 31 were overlapped to form a laminated scattering plate.

  The direction in which the refractive index in the optical film surface of the groove parallel sample 30 is large (indicated by a broken line arrow) and the direction in which the refractive index in the optical film surface of the groove orthogonal sample 31 is large (indicated by a broken line arrow) are aligned in parallel. It has been. Therefore, the groove direction of the groove parallel sample 30 (shown by solid line arrows) and the groove direction of the groove orthogonal sample 31 (shown by solid line arrows) are arranged orthogonally (on a plan view).

  In the third experiment, the light transmittance with respect to normal incidence light and oblique incidence light was measured for the laminated scattering plate. The measurement system of the third experiment is the same as the measurement system of the first and second experiments (see FIGS. 4 and 7). However, the single-layer scattering plate 5 of the measurement system of the first and second experiments is replaced with a laminated scattering plate, and the receiver angle (viewing angle) and the projector angle (incident angle) are 0 ° in the normal direction of the substrate. And changed in a plane perpendicular to the direction in which the refractive index is large.

  For the laminated scattering plate, the polarizing plate parallel arrangement with the polarizing plate transmission axis parallel to the direction with a large refractive index, and the polarizing plate orthogonal arrangement with the polarizing plate transmission axis perpendicular to the direction with a large refractive index, Measurements were made. In addition, although the polarizing plate parallel / orthogonal arrangement in the first and second experiments is defined with respect to the groove direction, it is defined here with respect to the direction in which the refractive index is large.

  14 to 16 are graphs showing light transmittances at incident angles of 0 °, 10 °, and 20 °, respectively. The horizontal axis shows the receiver angle in degrees, and the vertical axis shows the light transmittance in%.

  As shown in FIGS. 14 to 16, at the incident angles of 0 °, 10 °, and 20 °, similarly to the first and second experiments, the polarizing plate transmission axis direction is a direction in which the refractive index of the laminated optical film is large. When they are aligned, a high transmittance is obtained. The difference in brightness is about 13%, about 13%, and about 20% at incident angles of 0 °, 10 °, and 20 °, respectively, and a tendency to increase as the incident angle increases is observed.

  Similarly to the second experiment, in the case of oblique incidence (incidence angles of 10 ° and 20 °), both the parallel arrangement of the polarizing plates and the orthogonal arrangement of the polarizing plates exhibit the light transmittance distribution at an angle smaller than the incident angle of the oblique incidence. A peak is located, and there is a tendency that a lot of light is emitted upward (in the normal direction of the substrate).

  It should be noted that similar characteristics will be obtained even in a laminated scattering plate structure in which a groove orthogonal sample is arranged on the light incident side.

  Thus, it has been found that even when a plurality of optical films are laminated with the direction of the high refractive index aligned, a large amount of the polarized light component in the direction of the high refractive index is emitted.

  As described above, an optical film having a concavo-convex structure for scattering incident light and having a refractive index anisotropy having a large refractive index in one direction within the film surface refracts a polarization component in a direction with a large refractive index. The light can be emitted more strongly than the polarized light component in the direction where the rate is small.

  By combining such an optical film and a polarizing plate whose transmission axis direction is aligned with the direction in which the refractive index of the optical film is large, an optical device that emits bright polarized light can be obtained.

  Such an optical film can be easily produced, for example, by transferring the concavo-convex structure to an ultraviolet curable liquid crystal material with a stamper.

  In addition, the optical film of an Example should be applied to the general liquid crystal display apparatus using a backlight, such as an in-vehicle display, an amusement display, a mobile phone / digital camera display, an audio display, a personal computer monitor display, and a television display. Can do.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

DESCRIPTION OF SYMBOLS 1a Transparent substrate 1b Alignment film | membrane 1 (The alignment process was performed) Substrate 2 Optical film 3 Stamper substrate 4 Ultraviolet ray 5 Scattering plate 6 Polarizing plate 10 Projector 11 Receiver 20 Backlight 21 Scattering plate 22 Liquid crystal display elements 22a and 22c Polarizing plate 22b Liquid crystal cell 30 Groove parallel sample 31 Groove orthogonal sample

Claims (8)

A first substrate that has been subjected to an alignment treatment in a first direction;
A liquid crystal material is formed on the first substrate, and the liquid crystal is oriented in the first direction and has a refractive index anisotropy having a large refractive index, and the length direction of the grooves is along one direction and the pitch of the grooves. and has a irregularly shaped groove structure not constant depth, a first optical film to grant diffuse-scattering property with respect to incident light,
An optical device comprising: a polarizing plate having a transmission axis direction arranged in parallel with the first direction. The length direction of the groove of the first optical film, the optical device according to claim 1 which is aligned with the first direction. further,
With backlight,
A liquid crystal display element having a liquid crystal cell sandwiched between a pair of polarizing plates arranged on the backlight side of the polarizing plate;
Wherein the backlight, between the backlight side polarizing plate, an optical device according to claim 1 or 2, wherein the first optical film is disposed. further,
A second substrate having been subjected to an alignment treatment in a second direction parallel to the first direction;
The liquid crystal material is formed on the second substrate, the liquid crystal is oriented in the second direction and has a large refractive index, and the groove length direction intersects with the second direction. A second optical film having a groove structure in which the pitch and the depth of the grooves are irregularly formed along one direction and imparts irregular reflection / scattering properties to incident light ;
Have
The second substrate and the second optical film are between the first substrate and the first optical film and the polarizing plate, or with respect to the first substrate and the first optical film. The optical device according to claim 2 , wherein the optical device is disposed on a side opposite to the polarizing plate. (A) It is formed of an ultraviolet curable liquid crystal material on a substrate that has been subjected to an alignment treatment for the liquid crystal material, and the groove length direction is in one direction, and the groove pitch and depth are not constant and irregular. Forming an optical film having a groove structure;
(B) irradiating the optical film with ultraviolet rays;
A method for manufacturing an optical device. 6. The optical system according to claim 5 , wherein the step (a) includes a step of forming an ultraviolet curable liquid crystal material film on the substrate and a step of transferring the groove structure from the mold having the groove structure to the liquid crystal material film. Device manufacturing method. 6. The method of manufacturing an optical device according to claim 5 , wherein the step (a) includes a step of injecting an ultraviolet curable liquid crystal material between the substrate and a mold having a groove structure. further,
(C) The optical according to any one of claims 5 to 7 , further comprising a step of disposing a polarizing plate so that a direction in which the refractive index is large and a transmission axis direction are parallel to each other within the film surface of the optical film. Device manufacturing method.