JP2009192586A - Wire grid polarizer and display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire grid polarizer capable of having sufficient color reproducibility and providing black display when disposed in a display device such as a liquid crystal display device. <P>SOLUTION: The wire grid polarizer comprises a base material 1 having lattice-shaped projections 1a provided successively at predetermined intervals, a light-reflecting material wire 4 formed on the lattice-shaped projections 1a, an intermediate layer 3 formed on the light-reflecting material wire 4 and attenuating light entering the inside, and a half-transmission layer 2 formed on the intermediate layer 3 and transmits part of light inside. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wire grid type polarizing element and a display device using the same.

  With the recent development of photolithography technology, it has become possible to form a fine structure pattern having a pitch at the wavelength level of light. Such a member or product having a pattern with a very small pitch is useful in a wide range of applications not only in the semiconductor field but also in the optical field.

  For example, a wire grid in which conductor wires made of metal or the like are arranged in a lattice pattern at a specific pitch has a pitch that is considerably smaller than incident light (for example, visible light wavelength 400 nm to 800 nm). For example, if it is less than half, most of the electric field vector component light that oscillates in parallel to the conductor line is reflected, and almost no electric field vector component light perpendicular to the electric conductor line is transmitted. It can be used as a polarizing plate that produces a single polarized light. The wire grid type polarizing element is desirable from the viewpoint of effective use of light because it can reflect and reuse light that does not pass through.

An example of such a wire grid type polarizing element is disclosed in Patent Document 1. The wire grid polarizer includes light reflecting material wires spaced at a grid period smaller than the wavelength of incident light.
JP 2002-328234 A

  However, in the configuration disclosed in Patent Document 1, the light reflecting material wire reflects not only the light from the backlight side but also the light from the outside light side, so that the wire grid polarizer is like a liquid crystal display device. When it is provided in a display device, there is a problem that sufficient color reproducibility and black display cannot be performed.

  The present invention has been made in view of the above points, and provides a wire grid type polarizing element capable of realizing sufficient color reproducibility and black display when disposed in a display device such as a liquid crystal display device. Objective.

  The wire grid type polarizing element of the present invention includes a base material, a light absorption layer formed on the base material in a lattice shape at a predetermined interval and made of a material containing carbon, and the light absorption layer on the light absorption layer. It is characterized by comprising an adhesive layer formed of a material having good adhesion to carbon, and a light reflecting material wire formed on the adhesive layer.

  The wire grid type polarizing element of the present invention includes a base material, a light reflecting material wire formed in a lattice shape on the base material at a predetermined interval, and formed on the light reflecting material wire, It is characterized by comprising: an adhesive layer made of a material having good adhesiveness; and a light absorption layer formed on the adhesive layer and made of a material containing carbon.

  In the wire grid type polarizing element of the present invention, it is preferable that the light reflecting material wire is made of a material having good adhesion to carbon and also serves as the adhesive layer.

  In the wire grid type polarizing element of the present invention, the material having good adhesion to carbon is chromium, molybdenum, tungsten, titanium, zirconium, hafnium, niobium, tantalum, nickel, copper, aluminum, silicon, and each. It is preferably selected from the group consisting of compounds of these elements.

  In the wire grid type polarizing element of the present invention, it is preferable that the light reflecting material wire is made of a material selected from the group consisting of chromium, titanium, tantalum, aluminum, silver and a compound of each element.

  The manufacturing method of the wire grid type polarizing element of the present invention includes a step of obtaining a base material having lattice-like convex portions arranged in parallel at a predetermined interval, and light composed of a material containing carbon on the base material. A step of forming an absorption layer, a step of forming an adhesive layer made of a material having good adhesion to carbon on the light absorption layer formed on the lattice-shaped convex portions and on the side surfaces, And a step of forming a light reflecting material wire on the adhesive layer, and a step of etching the light absorbing layer formed between the lattice-shaped convex portions using the light reflecting material wire as a mask.

  The manufacturing method of the wire grid type polarizing element of the present invention includes a step of obtaining a base material having lattice-like convex portions arranged in parallel at a predetermined interval, and light composed of a material containing carbon on the base material. A step of forming an absorption layer, and a step of forming a light-reflecting material wire made of a material having good adhesion to carbon on the light absorption layer formed on the lattice-shaped convex portions and on the side surfaces; And a step of dry-etching the light absorption layer formed between the lattice-shaped convex portions using the light reflecting material wire as a mask.

  The display device of the present invention comprises a display device, an illuminating means for illuminating the display device, and the wire grid type polarizing element, wherein the light reflecting material wire surface is illuminated with the light reflecting material wire surface. It is arranged on the means side.

  The wire grid type polarizing element of the present invention includes a base material, a light absorption layer formed on the base material in a lattice shape at a predetermined interval and made of a material containing carbon, and the light absorption layer on the light absorption layer. An adhesive layer formed of a material having good adhesion to carbon, and a light-reflective material wire formed on the adhesive layer, or a base material, on the base material A light-reflective material wire formed in a grid pattern at a predetermined interval; an adhesive layer formed on the light-reflective material wire and made of a material having good adhesion to carbon; and the adhesive layer And a light absorption layer made of a material containing carbon, so that when arranged in a display device such as a liquid crystal display device, sufficient color reproducibility and black display can be realized. it can.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIGS. 1A and 1B are schematic views showing a part of a wire grid type polarizing element according to an embodiment of the present invention. The wire grid type polarizing element shown in FIG. 1A includes a base material 1 in which grid-like convex portions 1a are arranged in parallel at predetermined intervals, and carbon provided on the grid-like convex portions 1a of the base material 1. A light-absorbing layer 2 made of a material including the adhesive layer 3 formed on the light-absorbing layer 2 and made of a material having good adhesion to carbon, and a light reflection formed on the adhesive layer 3. The material wire 4 is mainly composed of. In addition, the light absorption layer 2 provided on the grid | lattice-like convex part 1a may be provided so that at least one part of the side surface of the grid | lattice-like convex part 1a may be covered. When this wire grid type polarizing element is mounted on a display device having illumination means such as a backlight, the base material 1 is positioned on the outside light side, and the light reflecting material wire 4 is positioned on the backlight side. It is arranged. The form of the wire grid type polarizing element may be a film-like body or a plate-like body.

  Further, the wire grid type polarizing element shown in FIG. 1B is provided on a base material 1 in which grid-like convex portions 1a are arranged in parallel at predetermined intervals and on the grid-like convex portions 1a of the base material 1. The light reflecting material wire 4, the adhesive layer 3 formed on the light reflecting material wire 4 and made of a material having good adhesion to carbon, and the material formed on the adhesive layer 3 and containing carbon The light absorption layer 2 is mainly composed of. When this wire grid type polarization element is mounted on a display device having illumination means such as a backlight, the light absorption layer 2 is positioned on the outside light side, and the substrate 1 is positioned on the backlight side. Arranged. The form of the wire grid type polarizing element may be a film-like body or a plate-like body.

  As a material which comprises the base material 1, what is necessary is just a resin substantially transparent with respect to the light made into object. For example, inorganic materials such as glass and organic materials such as resins include polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, cycloolefin resin (COP), cross-linked polyethylene resin, polyvinyl chloride resin, polyarylate resin, polyphenylene ether Amorphous thermoplastic resins such as resins, modified polyphenylene ether resins, polyetherimide resins, polyether sulfone resins, polysulfone resins, polyether ketone resins, polyethylene terephthalate (PET) resins, polyethylene naphthalate resins, polyethylene resins, Crystalline thermoplastic resins such as polypropylene resin, polybutylene terephthalate resin, aromatic polyester resin, polyacetal resin, polyamide resin, acrylic, epoxy, urethane, etc. They include ultraviolet (UV) curable resin or thermosetting resin. Moreover, it can also be set as the structure which combined the ultraviolet curable resin and thermosetting resin which are the resin base materials 1 as a base material, inorganic board | substrates, such as glass, the said thermoplastic resin, and a triacetate resin.

  The pitch of the grid-like convex portions 1a of the substrate 1 is determined by the polarization characteristics of the target light, and is generally ½ or less of the wavelength of the light. The smaller the pitch, the better the polarization characteristics. For example, good polarization characteristics can be obtained at 80 to 150 nm for visible light.

  There is no limitation on the cross-sectional shape of the concave portions of the fine concavo-convex lattice formed by the lattice-like convex portions 1a and the plurality of lattice-like convex portions. For example, these cross-sectional shapes may be a sine wave shape such as a trapezoidal shape, a rectangular shape, a square shape, a prism shape, or a semicircular shape. Here, the sinusoidal shape means that it has a curved portion formed by repetition of a concave portion and a convex portion. In addition, the curved part should just be a curved curve, for example, the shape which has a constriction in a convex part is also included in a sine wave form.

  Although there is no particular limitation on the method for obtaining the substrate having the lattice-shaped convex portions of the present invention, it is preferable to use the method described in Japanese Patent Application Laid-Open No. 2006-224659 by the present applicant.

  Specifically, in the present invention, as a method I for obtaining a substrate having a lattice-shaped convex portion, a stretched member having a concave-convex lattice with a pitch of 100 nm to 100 μm on the surface is used as a longitudinal direction of the concave-convex lattice (lattice-shaped convex portion). It is preferable to fabricate the stretched member by free end uniaxial stretching in a direction substantially parallel to the longitudinal direction in a state in which the width of the stretched member in a direction substantially orthogonal to the lattice is free. As a result, the pitch of the convex portions of the concavo-convex grid of the stretched member is reduced, and a substrate (stretched member) having a fine concavo-convex grid is obtained. The pitch of the concavo-convex grid is set in the range of 100 nm to 100 μm, but can be appropriately changed according to the required pitch of the fine concavo-convex grid and the draw ratio.

  Here, the stretched member refers to a transparent substrate such as a plate-like body, a film-like body, or a sheet-like body composed of an amorphous thermoplastic resin or a crystalline thermoplastic resin as a base material used in the present invention. Can be mentioned. The thickness and size of the stretched member are not particularly limited as long as the uniaxial stretching process is possible.

In addition, in order to obtain a stretched member having a concavo-convex lattice with a pitch of 100 nm to 100 μm on the surface, a mold having a concavo-convex lattice with a pitch of 100 nm to 100 μm formed by an interference exposure method using laser light or a cutting method is used. The concavo-convex lattice shape may be transferred to the stretched member by a method such as hot pressing. The interference exposure method is an exposure method using interference fringes formed by irradiating laser light of a specific wavelength from two directions of angle θ ′, and is used by changing the angle θ ′. It is possible to obtain an uneven grating structure having various pitches within the laser wavelength range. As the laser that can be used for the interference exposure, limited to laser _{TEM 00} mode, as the ultraviolet light laser capable lasing of _{TEM 00} mode, an argon laser (wavelength 364 nm, 351 nm, 333 nm) and, of YAG laser fourth harmonic ( Wavelength 266 nm).

  In the uniaxial stretching treatment in the present invention, first, the width direction of the stretched member (direction perpendicular to the longitudinal direction of the concavo-convex lattice) is set free, and the longitudinal direction of the concavo-convex lattice of the stretched member is changed to a uniaxial stretch treatment apparatus. Fix it. Subsequently, after heating to an appropriate temperature at which the stretched member softens and holding it for an appropriate period of time, the pitch of the target fine concavo-convex lattice is set at an appropriate drawing speed in one direction substantially parallel to the longitudinal direction. Stretching is performed up to a stretching ratio corresponding to. Finally, the member to be stretched is cooled to a temperature at which the material is cured in a state where the stretched state is maintained, thereby obtaining a base material having lattice-shaped convex portions. As an apparatus for performing this uniaxial stretching process, an apparatus for performing a normal uniaxial stretching process can be used. Further, the heating condition and the cooling condition are appropriately determined according to the material constituting the stretched member.

  Further, in the present invention, the method II for obtaining a substrate having a lattice-like convex portion is a method of transferring a fine concavo-convex lattice onto the surface of the substrate used in the present invention using a mold having a fine concavo-convex lattice on the surface, and molding It is a method to do. Here, a mold having a fine concavo-convex lattice on the surface is prepared by sequentially performing a conductive treatment, a plating treatment, and a resin base material removal treatment on a base material having a lattice-like convex portion obtained by Method I. Can do.

  According to this method, since the mold having the lattice-shaped convex portions is used, it is possible to mass-produce the substrate having the lattice-shaped convex portions used in the present invention without going through a complicated stretching process. Furthermore, by appropriately combining and repeatedly using Method I and Method II, it becomes possible to produce a finer concavo-convex grid from a concavo-convex grid having a relatively large pitch.

  The light absorption layer 2 is made of a material containing carbon and exhibits a function of reducing the vertical reflectance of light incident from the outside light side. Here, examples of the material containing carbon include carbon alone, a mixture of carbon alone and metal, a dielectric, and other materials, and carbide. In particular, it is preferable that carbon alone is included because unnecessary portions can be easily removed by dry etching using oxygen plasma. The thickness of the light absorption layer 2 is not particularly limited as long as it is a thickness that can sufficiently absorb external light. As a method for forming the light absorption layer 2, for example, a physical vapor deposition method such as a sputtering method or an ion plating method or a plasma CVD method using a gas containing carbon as a raw material can be suitably used.

  The adhesive layer 3 is made of a material having good adhesion to carbon, and has a function of improving the adhesion between the light absorbing layer 2 made of a material containing carbon and the light reflecting material wire 4. Demonstrate. Specific examples of materials having good adhesion to carbon include chromium, molybdenum, tungsten, titanium, zirconium, hafnium, niobium, tantalum, nickel, copper, silicon, and compounds of the respective elements. .

  Moreover, as a method of forming the adhesive layer 3, for example, a physical vapor deposition method such as a vacuum vapor deposition method or a sputtering method can be suitably used.

  It is preferable that the light reflecting material constituting the light reflecting material wire 4 has a high light reflectance in a desired wavelength region. For example, chromium, titanium, tantalum, aluminum, silver, or a compound of each element can be used. Moreover, as a method of forming the light reflecting material wire 4, for example, a physical vapor deposition method such as a vacuum vapor deposition method, a sputtering method, or an ion plating method can be suitably used.

  In the wire grid type polarizing element of the present invention having such a configuration, the light from the backlight side is reflected by the light reflecting material wire 4 as shown in FIGS. Is absorbed by the light absorption layer 2. Thereby, the vertical reflectance of the light from the outside light side can be 20% or less. Here, the vertical reflectance refers to the reflectance when incident light is incident perpendicularly to the wire grid type polarizing element.

  In the wire grid type polarizing element of the present invention, the light absorbing layer 2 is made of a material containing carbon, and the light reflecting material wire 4 is bonded to the light reflecting material wire 4 with a material having good adhesion to carbon. Layer 3 is provided. The present invention is not limited to this embodiment, and can be configured without the adhesive layer 3 as long as the light reflecting material wire 4 is made of a material having good adhesion to carbon. That is, as shown in FIG. 2A, the wire grid type polarizing element is formed on a base material 1 in which grid-like convex portions 1a are arranged in parallel at predetermined intervals, and on the grid-like convex portions 1a of the base material 1. The light absorption layer 2 made of a material containing carbon and the light reflecting material wire 5 made of a material that is formed on the light absorption layer 2 and has good adhesion to carbon. As shown in FIG. 2 (b), the substrate 1 is provided with the lattice-like convex portions 1a arranged in parallel at predetermined intervals, and is provided on the lattice-like convex portions 1a of the substrate 1. The light reflecting material wire 5 and the light absorbing layer 2 formed on the light reflecting material wire 5 and made of a material containing carbon may be mainly configured. Since the light reflecting material wire 5 in FIGS. 2 (a) and 2 (b) is made of a material having good adhesion to carbon, an adhesive layer of the light absorbing layer 2 made of a material containing carbon is used. I also serve.

  When the wire grid type polarizing element shown in FIG. 2A is mounted on a display device having illumination means such as a backlight, the substrate 1 is positioned on the outside light side, and the light reflecting material wire 5 is back. The wire grid type polarizing element shown in FIG. 2B is disposed so as to be positioned on the light side, and when the light absorption layer 2 is attached to a display device having an illuminating means such as a backlight, the light absorption layer 2 is external light. The base material 1 is disposed on the backlight side. In this case as well, the wire grid type polarizing element may be in the form of a film or a plate.

  As described above, the wire grid type polarizing element having the above configuration sufficiently reflects the light from the backlight side by the light reflecting material wire 4 when it is disposed in a display device having illumination means such as a backlight. In addition, external light can be absorbed by the light absorption layer 2 and reflection by external light can be suppressed as much as possible. Thereby, sufficient color reproducibility and black display can be realized in the display device.

  When manufacturing a wire grid type polarizing element having the configuration shown in FIG. 1A, first, a grid-like convex having a fine concavo-convex grating produced in parallel with a predetermined interval is manufactured. 3), a light-absorbing material made of a material containing carbon is formed on the lattice-shaped convex portions 1a of the fine concavo-convex lattice and on the side surfaces thereof, as shown in FIG. Then, the light absorption layer 2 is formed, and as shown in FIG. 3B, a material having good adhesion to carbon is formed on the light absorption layer 2 to form the adhesion layer 3. . Thereafter, as shown in FIG. 3C, a light reflecting material is formed on the adhesive layer 3 to form a light reflecting material wire 4. In this case, in forming the adhesive layer 3 and the light reflecting material wire 4, the film is formed from a predetermined angle with respect to the standing direction of the light reflecting material wire 4 in the cross sectional view (in the direction of the arrow). Thereafter, the light reflecting material wire 4 formed between the lattice-shaped convex portions is removed by etching such as wet etching, and the light absorbing layer 2 formed between the lattice-shaped convex portions using the light reflecting material wire 4 as a mask. Etch. For etching the light absorption layer, dry etching such as reactive etching (RIE) using oxygen plasma is preferable. According to the dry etching, it is possible to remove only the unnecessary light absorbing layer including the exposed carbon alone without damaging the light reflecting material wire and the light absorbing layer immediately below.

  When manufacturing a wire grid type polarizing element having the configuration shown in FIG. 2 (a), first, a grid-like convex having a fine concavo-convex lattice produced by the above-described method (arranged in parallel at a predetermined interval). 4), a light-absorbing material made of a material containing carbon is formed on the lattice-shaped convex portions 1a and the side surfaces of the fine concave-convex lattice as shown in FIG. Then, the light absorbing layer 2 is formed. Further, as shown in FIG. 4B, a material having good adhesion to carbon is formed on the light absorbing layer 2 to form the light reflecting material wire 5. Form. In this case, in the formation of the light reflecting material wire 5, the film is formed from a predetermined angle with respect to the standing direction of the light reflecting material wire 5 in a cross sectional view (in the direction of the arrow). Thereafter, the light reflecting material wire 5 formed between the lattice-shaped convex portions is removed by etching such as wet etching, and the light absorbing layer 2 formed between the lattice-shaped convex portions is etched using the light reflecting material wire 5 as a mask. To do. For etching the light absorption layer, dry etching such as reactive etching (RIE) using oxygen plasma is preferable. According to the dry etching, it is possible to remove only the unnecessary light absorbing layer including the exposed carbon alone without damaging the light reflecting material wire and the light absorbing layer immediately below.

  1A and 2A, when the light absorbing layer 2 is formed by forming a light absorbing material made of a material containing carbon, the light reflecting material wire 4 in a cross-sectional view. It is also possible to form a film from a predetermined angle with respect to the standing direction (arrow direction). In this case, adhesion of the light absorbing material between the convex portions can be reduced or suppressed, and etching in a later process can be reduced or omitted.

  When manufacturing a wire grid type polarizing element having the configuration shown in FIG. 1B, first, a grid-like convex having a fine concavo-convex grating produced in parallel with a predetermined interval is manufactured. The substrate 1 is prepared), and a light reflecting material wire 4 is formed by forming a light reflecting material on the lattice-shaped convex portions 1a and the side surfaces of the fine concavo-convex lattice, and is formed between the lattice-shaped convex portions. The light reflecting material wire 4 is etched. Next, a material having good adhesion to carbon is formed on the light reflecting material wire 4 to form the adhesive layer 3. Thereafter, a light absorbing material made of a material containing carbon is formed on the adhesive layer 3 to form the light absorbing layer 2. In this case, in the formation of the adhesive layer 3 and the light absorption layer 2, the film is formed from a predetermined angle with respect to the standing direction of the light reflecting material wire 4 in a cross sectional view.

  When manufacturing a wire grid type polarizing element having the configuration shown in FIG. 2B, first, a grid-like convex having a fine concavo-convex lattice produced by the above-described method (arranged in parallel at a predetermined interval). A material 1 having a good adhesion to carbon is formed on the lattice-like convex portions 1a and side surfaces of the fine concavo-convex lattice to form a light reflecting material wire 5; The light reflecting material wire 5 formed between the lattice-shaped convex portions is etched. Next, a material having good adhesion to carbon is formed on the light reflecting material wire 5 to form the light absorbing layer 2. In this case, in the formation of the light absorption layer 2, the film is formed from a predetermined angle with respect to the standing direction of the light reflecting material wire 5 in the cross sectional view.

  Next, the case where the wire grid type polarizing element according to the present invention is used in a liquid crystal display device will be described. FIG. 5 is a view showing a liquid crystal display device including the wire grid type polarizing element according to the embodiment of the present invention.

  The liquid crystal display device shown in FIG. 5 is arranged on an illumination device 11 such as a backlight that emits light, a wire grid polarization element 12 disposed on the illumination device 11, and the wire grid polarization element 12. The liquid crystal cell 13 is mainly composed. That is, the wire grid type polarizing element 12 according to the present invention is disposed between the liquid crystal cell 13 and the illumination device 11. The liquid crystal cell 13 is configured by sandwiching a liquid crystal layer between a pair of substrates. The liquid crystal cell 13 is a transmissive liquid crystal cell, and is configured by sandwiching a liquid crystal material or the like between glass and a transparent resin substrate. In the liquid crystal display device of FIG. 5, description of various optical elements such as a polarizing plate protective film, a retardation film, a diffusion plate, an alignment film, a transparent electrode, and a color filter that are usually used is omitted.

  In FIG. 5, when the wire grid type polarization element 12 has the configuration shown in FIGS. 1A and 2A, the light reflecting material wire 4 of the wire grid type polarization element 12 is placed on the illumination device 11 side, and the substrate 1. Is arranged toward the liquid crystal cell 13 side, and the wire grid type polarizing element 12 has the configuration shown in FIGS. 1B and 2B, the base material 1 of the wire grid type polarizing element 12 is the illumination device 11. On the side, the light absorption layer 2 is disposed toward the liquid crystal cell 13 side.

  In the liquid crystal display device having such a configuration (when the wire grid type polarizing element shown in FIG. 1A is provided), light emitted from the illumination device 11 is on the light reflecting material wire 4 side of the wire grid type polarizing element 12. From the base material 1 side, passes through the liquid crystal cell 13 and is emitted to the outside (in the direction of the arrow in the figure). In this case, since the wire grid type polarizing element 12 exhibits an excellent degree of polarization in the visible light region, a display with a high contrast can be obtained. On the other hand, part of the outside light passes through the liquid crystal cell 13 and is absorbed by the light absorption layer 2 of the wire grid type polarizing element 12. For this reason, the external light reflected by the wire grid type polarizing element 12 becomes weak. Therefore, since the light from the illumination device 11 is efficiently reflected and the external light is efficiently absorbed by the wire grid type polarizing element, sufficient color reproducibility and black display can be realized in the liquid crystal display device. .

Next, examples performed for clarifying the effects of the present invention will be described.
(Example 1)
By the above-described method, a corrugated cross-sectional shape in which the convex tip is tapered on one side of a TAC (Triacetylcellulose) base material by UV transfer with a pitch of 140 nm, a height of about 150 nm, and a width at half height of about 60 nm. A film provided with a fine concavo-convex lattice was prepared, and a carbon was deposited to a thickness of 50 nm on this film by a DC magnetron sputtering method to form a light absorption layer. Next, on the lattice-shaped convex portion of the fine concavo-convex lattice, a DC magnetron sputtering method is used to form an adhesive layer by depositing chromium with a thickness of 30 nm from above, which is inclined by 30 ° from the vertical direction. Then, a light reflecting material wire was formed by depositing aluminum with a thickness of 30 nm from the upper side inclined by 30 ° from the vertical direction by a DC magnetron sputtering method. Then, the film was immersed in the diluted sodium hydroxide aqueous solution, and the excess aluminum adhering between lattice-shaped convex parts was removed by wet etching. Thereby, the wire grid was formed on the light absorption layer.

About the obtained wire grid, the transmittance | permeability was measured using the spectrophotometer. Here, the transmitted light intensity in a parallel Nicols state and a crossed Nicols state with respect to linearly polarized light was measured, and the transmittance was calculated from the following equation.
Light transmittance = (Imax + Imin) / 2 × 100%
Here, Imax is the transmitted light intensity at the time of parallel Nicols, and Imin is the transmitted light intensity at the time of crossed Nicols.
As a result, the transmittance was 8.7%.

  Next, the film was dry-etched in an oxygen atmosphere to remove the exposed light absorption layer (mainly the light absorption layer between the lattice-shaped convex portions). Thus, the wire grid type polarizing element of Example 1 was produced.

  About the obtained wire grid type polarizing element of Example 1, the vertical reflectance with respect to external light was investigated. Each vertical reflectance was measured with a spectrophotometer. As a result, the vertical reflectance with respect to external light (wavelength 550 nm) was 14%.

Moreover, about the obtained wire grid type polarizing element of Example 1, the degree of polarization and the transmittance | permeability were measured using the spectrophotometer. Here, the transmitted light intensity in a parallel Nicols state and a crossed Nicols state with respect to linearly polarized light was measured, and the degree of polarization was calculated from the following equation. The transmittance was calculated from the above formula.
Polarization degree = (Imax−Imin) / (Imax + Imin) × 100%
Here, Imax is the transmitted light intensity at the time of parallel Nicols, and Imin is the transmitted light intensity at the time of crossed Nicols.
As a result, the degree of polarization was 98.3% and the transmittance was 18.4%.

(Example 2)
A wire grid type polarizing element of Example 2 was produced in the same manner as in Example 1 except that the thickness of the aluminum light reflecting material wire was set to 80 nm. About the obtained wire grid type polarizing element of Example 2, the vertical reflectance with respect to external light was investigated in the same manner as in Example 1. Each vertical reflectance was measured with a spectrophotometer. As a result, the vertical reflectance with respect to external light (wavelength 550 nm) was 14%. Further, the degree of polarization and transmittance of the wire grid type polarizing element obtained in Example 2 were measured in the same manner as in Example 1. As a result, the degree of polarization was 97.5% and the transmittance was 25.6%.

(Example 3)
Using the method described above, a film having a fine concavo-convex grid formed on one side of a TAC substrate by UV transfer is prepared, and a light absorption layer is formed on this film by DC magnetron sputtering to form a carbon film with a thickness of 50 nm. did. Next, on the lattice-shaped convex portions of the fine concavo-convex lattice, a film of chromium having a thickness of 50 nm was formed from above by tilting 30 ° from the vertical direction by a DC magnetron sputtering method to form an adhesive layer / light reflecting material wire. Next, the film was dry-etched in an oxygen atmosphere to remove the exposed light absorption layer (mainly the light absorption layer between the lattice-shaped convex portions). Thus, the wire grid type polarizing element of Example 3 was produced.

  With respect to the obtained wire grid type polarizing element of Example 3, the vertical reflectance with respect to external light was examined in the same manner as in Example 1. Each vertical reflectance was measured with a spectrophotometer. As a result, the vertical reflectance with respect to external light (wavelength 550 nm) was 14%. Further, the degree of polarization and the transmittance of the wire grid type polarizing element obtained in Example 3 were measured in the same manner as in Example 1. As a result, the degree of polarization was 67.2%, and the transmittance was 41%.

Example 4
Using the method described above, a film having a fine concavo-convex grid formed on one side of a TAC substrate by UV transfer is prepared, and a light absorption layer is formed on this film by DC magnetron sputtering to form a carbon film with a thickness of 50 nm. did. Next, on the lattice-shaped convex portions of the fine concavo-convex lattice, aluminum was formed in a thickness of 50 nm from the upper side inclined by 30 ° from the vertical direction by a DC magnetron sputtering method to form an adhesive layer / light reflecting material wire. Next, the film was dry-etched in an oxygen atmosphere to remove the exposed light absorption layer (mainly the light absorption layer between the lattice-shaped convex portions). Thus, the wire grid type polarizing element of Example 4 was produced.

  With respect to the obtained wire grid polarizing element of Example 4, the vertical reflectance with respect to external light was examined in the same manner as in Example 1. Each vertical reflectance was measured with a spectrophotometer. As a result, the vertical reflectance with respect to external light (wavelength 550 nm) was 14%. Further, the transmittance of the obtained wire grid type polarizing element of Example 4 was measured in the same manner as in Example 1. As a result, the transmittance before dry etching was 18%, and the transmittance after dry etching was 23%.

(Comparative example)
By the above-described method, a film provided with a fine concavo-convex grid by UV transfer on one side of a TAC base material is prepared, and aluminum is vapor-deposited at a thickness of 150 nm on the film from above at an angle of 30 ° with respect to the vertical direction. A reflective material wire was formed. Then, the film was immersed in the diluted sodium hydroxide aqueous solution, and the excess aluminum adhering between lattice-shaped convex parts was removed by wet etching. Thus, the wire grid type polarizing element of the comparative example was produced.

  About the obtained wire grid type polarizing element of the comparative example, it carried out similarly to Example 1, and investigated the vertical reflectance with respect to external light. Each vertical reflectance was measured with a spectrophotometer. As a result, the vertical reflectance with respect to external light (wavelength: 510 nm) was 60%. Further, the degree of polarization and the transmittance of the obtained wire grid type polarizing element of the comparative example were measured in the same manner as in Example 1. As a result, the degree of polarization was 99.4% and the transmittance was 38%.

  Thus, the wire grid type polarizing elements of Examples 1 to 4 can suppress reflection of external light because the light absorbing layer is disposed on the outside light side, but the wire grid type polarizing element of the comparative example Since no light absorption layer was provided, the reflection of outside light was large.

  The present invention is not limited to the embodiment described above, and can be implemented with various modifications. For example, in the above-described embodiment, the case where the light reflecting material wire is formed on the lattice-like convex portion of the base material in which the lattice-like convex portions are arranged in parallel at a predetermined interval is described. However, the present invention is not limited to this, and the same can be applied to the case where the light reflecting material wires are formed at predetermined intervals on a base material on which no grid-like convex portion is provided. In addition, the dimensions, materials, and the like in the above embodiment are illustrative, and can be implemented with appropriate changes. In addition, various modifications can be made without departing from the scope of the present invention.

(A), (b) is a figure which shows the wire grid type polarizing element which concerns on embodiment of this invention. (A), (b) is a figure which shows the wire grid type polarizing element which concerns on embodiment of this invention. (A)-(c) is a figure for demonstrating the process of manufacturing the wire grid type polarizing element which concerns on embodiment of this invention. (A), (b) is a figure for demonstrating the process of manufacturing the wire grid type polarizing element which concerns on embodiment of this invention. It is a figure which shows the liquid crystal display device equipped with the wire grid type polarizing element which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 1a Lattice-like convex part 2 Light absorption layer 3 Adhesive layer 4,5 Light reflection material wire 11 Illumination device 12 Wire grid type polarizing element 13 Liquid crystal cell

Claims (8)

  A base material, a light absorption layer formed on the base material at a predetermined interval in a lattice shape and composed of a material containing carbon, and formed on the light absorption layer, has good adhesion to carbon A wire grid type polarizing element, comprising: an adhesive layer made of a material that is a light reflecting material wire formed on the adhesive layer.   A base material, a light reflecting material wire formed in a lattice shape at a predetermined interval on the base material, and a material formed on the light reflecting material wire and having good adhesion to carbon. A wire grid type polarizing element comprising: an adhesive layer; and a light absorption layer formed on the adhesive layer and made of a material containing carbon.   3. The wire grid type polarizing element according to claim 1, wherein the light reflecting material wire is made of a material having good adhesion to carbon and also serves as the adhesive layer.   The material having good adhesion to carbon was selected from the group consisting of chromium, molybdenum, tungsten, titanium, zirconium, hafnium, niobium, tantalum, nickel, copper, aluminum, silicon, and compounds of the respective elements. 4. The wire grid type polarizing element according to claim 3, wherein the polarizing element is a wire grid type polarizing element.   5. The light reflecting material wire is composed of a material selected from the group consisting of chromium, titanium, tantalum, aluminum, silver, and a compound of each element. The wire grid type polarizing element as described in 2.   A step of obtaining a base material having lattice-like convex portions arranged in parallel at a predetermined interval, a step of forming a light absorption layer made of a material containing carbon on the base material, and the lattice-like convex portion Forming an adhesive layer made of a material having good adhesion to carbon on the light absorbing layer formed on the upper and side surfaces, and forming a light reflecting material wire on the adhesive layer; And a step of etching a light absorption layer formed between the lattice-shaped convex portions using the light reflecting material wire as a mask.   A step of obtaining a base material having lattice-like convex portions arranged in parallel at a predetermined interval, a step of forming a light absorption layer made of a material containing carbon on the base material, and the lattice-like convex portion Forming a light-reflective material wire made of a material having good adhesion to carbon on the light-absorbing layer formed on the upper and side surfaces, and the lattice-like convex using the light-reflective material wire as a mask. And a step of dry-etching the light absorption layer formed between the sections. A method of manufacturing a wire grid type polarizing element.   A display device, illumination means for illuminating the display device, and the wire grid type polarizing element according to any one of claims 1 to 5, wherein the wire grid type polarizing element is the light reflecting material. A display device, wherein a wire surface is disposed on the illumination means side.

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