JPH09281329A - Polarizer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizer which is low in insertion loss, facilitates the formation to a larger area and is less deteriorated in polarization characteristic and a process for producing the same. SOLUTION: A superfine particle dispersion prepd. by dispersing particles of metals or semiconductor of <=100Å grain size into an org. solvent is applied in the surface of a glass substrate 2 by dropping the dispersion to plural rows linearly at equal intervals and is then fired, by which the plural wire-shape bodies consisting of the metals or semiconductors are formed on the surface of the glass substrate 2. The arbitrary adjustment of the width of the wire-shape bodies formed on the surface of the glass substrate 2 is made possible by changing the width of the coating liquid and, therefore, the extremely fine wire-shaped bodies of <=500Å are easily formed linearly over the wide area. The polarizer of the large area which is low in the insertion loss is thus easily produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizer for converting light having a wavelength of 300 nm or more into linearly polarized light and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, metal thin wires (wires) such as gold and aluminum are arranged at minute intervals on the surface of a transparent substrate such as silver bromide or polyethylene as a polarizer for light with a wavelength longer than 2.5 μm. A wire grid polarizer made of is known. For the medium infrared (2.5 μm to 25 μm), a silver bromide substrate provided with metal fine lines at intervals of 0.3 μm is used for the far infrared (16 to 1000 μm). There is one in which thin aluminum wires are provided at intervals of 7 μm. The polarization degree is said to be about 97%. Further, as a polarizer for light having a long wavelength of 0.8 μm or more, a laminated polarizer in which a metal film and a dielectric film are alternately laminated is known. This polarizer has a thickness of several hundred n
A metal film is formed on the dielectric substrate of m by using a thin film technique such as a vacuum deposition method, and a plurality of metal films are stacked and then cut as shown in FIG. Has been put to practical use. The laminated polarizer is characterized in that it is small in size and can be expected to have a high extinction ratio of 60 dB or more and a low insertion loss of 0.1 dB or less and a large polarization ratio. Further, as another polarizer, a film-type polarizer obtained by impregnating a polymer sheet stretched in one direction with iodine is known. The film type polarizer is easy to increase in area,
It is generally used as a polarizer of a liquid layer display device.

[0003]

The above-mentioned conventional polarizers have the following drawbacks. The wire grid type polarizer has a drawback that the metal thin wire has a columnar shape and thus has poor adhesion to a polyethylene substrate, which is a support, and the metal thin wire is easily peeled off from the substrate and deformed. If the thin metal wire is deformed, the function as a polarizer will be impaired. Also, it is difficult to make fine metal wires with a diameter of 0.1 μm or less,
Moreover, since it is easy to cut, it is difficult to increase the area of the wire grid polarizer. In addition, the laminated polarizer has a high extinction ratio, a low insertion loss as described above, and is excellent in performance, but has a structure in which a dielectric film and a metal film are laminated, and thus it is extremely large in area. It is difficult and can only be used as a small optical element. In addition, a film-type polarizer can be made into a large sheet, and is suitable for increasing the area. However, it is also known as birefringence and biabsorption caused by stretching a polymer in one direction. Since it is an absorption-type polarizer that uses the difference in absorption loss due to, the transmittance of light is poor, and since irregularities in the polymer and scattering due to it adversely affect the performance, the transmittance is only about 50% at maximum. I can't hope. An object of the present invention is to solve the above-mentioned problems of the conventional technique, to provide a polarizer having a small insertion loss, a large area, and less deterioration in polarization characteristics, and a manufacturing method thereof.

[0004]

In order to solve the above-mentioned problems, the method for producing a polarizer according to the present invention is characterized in that, as described in claim 1, organic particles of metal or semiconductor having a particle size of 100 Å or less are used. Ultrafine particle dispersion liquid dispersed in a solvent is applied to the surface of a support plate transparent to visible light in a linear manner in a plurality of rows at equal intervals, followed by firing, thereby baking the surface portion of the support plate. In addition, a plurality of linear bodies made of metal or semiconductor are formed linearly and at equal intervals. According to the above-mentioned manufacturing method, the width of the linear body formed on the surface portion of the support plate is arbitrarily adjusted by changing the width of the coating liquid when the ultrafine particle dispersion liquid is applied dropwise to the surface of the support plate. Therefore, it is possible to easily form an extremely fine linear body of, for example, 500 Å or less in a linear shape over a wide area, reduce the insertion loss, and easily manufacture a large-area polarizer. Since the linear body formed on the surface portion of the support plate by this manufacturing method is well adhered to the support plate by the firing treatment, the linear body is not easily peeled from the support plate, and the conventional grid-type polarizer As described above, the linear body (thin metal wire) is not deformed and its function is not impaired, so that good polarization characteristics are always exhibited.

Further, in the polarizer according to the present invention, as described in claim 3, a plurality of linear bodies made of metal or semiconductor are linearly formed on the surface of the support which is transparent to visible light. In addition, assuming that the linear bodies are formed at equal intervals, the linear body is an ultrafine particle dispersion obtained by dispersing metal or semiconductor particles having a particle size of 100Å or less on the surface of the support in an organic solvent. It is characterized in that the liquid is applied dropwise onto the surface of the support plate and then baked. The above-mentioned polarizer has a so-called grid-type polarizer structure in which a plurality of linear bodies made of metal or semiconductor are formed linearly and at equal intervals on the surface of a support transparent to visible light. While holding the linear body, by adopting the one obtained by dropping and coating the ultrafine particle dispersion liquid on the surface of the support plate and then firing it, good adhesion between the linear body and the support plate can be obtained. Since it does not easily come off from the support plate, it is possible to easily cope with a large area.

In the above-mentioned polarizer and the method for producing the same according to the present invention, it is most preferable that the particle size is 50Å. Further, it is preferable that the width of the linear body is, for example, 500 Å or less as shown in claim 2 and its variation is within 20%. Further, it is preferable that the interval between the linear bodies is 0.5 to 2.0 μm and the variation is within 20%. When the width of the linear body is larger than 500 Å, the absorption becomes large in the visible light region. If the distance between the linear bodies is larger than 2.0 μm, the degree of polarization in the visible light region is small, and if it is smaller than 0.5 μm, the absorption is too large.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic front view showing an example of an embodiment of an ultrafine particle dispersion liquid coating step, which is one step in manufacturing a polarizer by the manufacturing method of the present invention,
FIG. 1 (b) is a schematic side sectional view, and FIG. 2 is a schematic plan view showing the ultrafine particle dispersion liquid coating step. In FIG. 1, 1
Is a dispersion liquid dropping device for dropping the ultrafine particle dispersion liquid onto the surface of the support plate. This dispersion liquid dropping device 1 includes a container 5 containing the ultrafine particle dispersion liquid 4 and the ultrafine particle dispersion liquid 4. , And a plurality of stainless steel needles 6 for dropping onto the surface 2a of the glass substrate 2. The dispersed droplet lowering device 1 is fixed to a fixing portion via a supporting member (not shown). On the other hand, the glass substrate 2 is horizontally mounted on the substrate mounting portion 3 and is moved in the direction of arrow A in FIG. 1B by a moving unit (not shown).

.. of the needles 6, 6, ..
Is fixed to the edge 8a of the upper opening 8 of the container 5. The needles 6, 6, ... Are attached to the glass substrate 2 at the bottom of the container 5.
Through holes 7, 7 arranged side by side in a direction orthogonal to the moving direction of
... Protruding downward through container 5 through needle points 6a, 6
are positioned and held near the upper surface 2a of the glass substrate 2. Further, each of the needles 6, 6, ... Is shown in FIG.
As shown in Fig. 2, the needle tips 6a, 6a, ... are tilted in the direction in which the glass substrate 2 is moved, and as shown in Fig. 2, the needle tips 6a, 6a ,. It is held in a state of being shifted by 5 mm in the moving direction of the substrate 2. The length of each needle 6, 6, ... Is about 2 cm.
The material of the ultrafine particles dispersed in the ultrafine particle dispersion liquid 4 is A
Metals such as u, Al, Cu, Fe, Ni and Co or alloys thereof, or semiconductors such as Ge, Si, Se and Te are used. As a method for producing ultrafine particles of this type, there are a wet method such as a sol-gel method, an arc discharge method and a vapor deposition method in a gas,
The vapor deposition method in gas is most suitable as the method for producing the ultrafine particles used in the present invention. In the vapor deposition method in a gas, a metal or a semiconductor placed in a crucible is heated by high frequency induction heating, evaporated in He gas, collided with He gas molecules to cool and condense to form particles, and become an isolated state. By supplying the vapor of the organic solvent to a certain particle, the surface of the particle is covered with the organic solvent to prevent the secondary aggregation of the particle and form ultrafine particles. Α-Terpineol is used as the organic solvent. The particle size of the particles is controlled by the pressure of He gas and the temperature of the evaporation source.

When performing the coating process of the ultrafine particle dispersion liquid 4 using the above-mentioned dispersion liquid drop device 1, the needles 6, 6, ... Of the dispersion liquid drop device 1 are sufficiently polished to remove the deposits. Further, the ultrafine particle dispersion liquid 4 to be put in the container 5 of the dispersion liquid lowering device 1 is diluted with a solvent to a predetermined concentration so as to have a predetermined viscosity which can be dropped at a constant flow rate through each of the needles 6, 6 ,. Keep it. Toluene or the like is used as the solvent. Then, an appropriate amount of the diluted ultrafine particle dispersion liquid 4 is put into the container 5 of the apparatus 1 for lowering dispersed droplets and the lid 9 is closed. When the above preparation is completed, the glass substrate 2 is placed on the substrate platform 3. At this time, the substrate mounting portion 3 is moved to the initial position, and the glass substrate 2 is set so that the coating start portion of the glass substrate 2 is located below the needle tips 6a, 6a, ... To do.

After that, the moving means (not shown) is actuated to start moving the substrate mounting portion 3 in the direction of the arrow A, and the dispersion liquid dropping device 1 starts dropping the ultrafine particle dispersion liquid 4. The moving speed of the substrate platform 3 is constant. As a result, the glass substrate 2 moving in the direction of arrow A at a constant speed
The ultrafine particle dispersion liquid 4 is dripped on the needles 6, 6, ... Of the dispersion droplet lowering device 1, and linearly and equidistantly on the surface 2a of the glass substrate 2 as shown in FIG. It is applied in multiple rows. The coating width of the ultrafine particle dispersion liquid 4 is the glass substrate 2
Can be adjusted by controlling the moving speed of the liquid and the flow rate at which the ultrafine particle dispersion liquid 4 is dropped. After the ultrafine particle dispersion liquid 4 is applied dropwise to the surface 2a of the glass substrate 2 as described above, the glass substrate 2 is transferred into an electric furnace and heated at a predetermined temperature for a predetermined time, whereby the surface 2a of the glass substrate 2 is heated. The ultrafine particle dispersion liquid 4 applied to the above is dried and baked. As a result, the particles of the metal or semiconductor in the ultrafine particle dispersion liquid 4 are made continuous by firing, and a plurality of linear bodies made of the metal or semiconductor are formed linearly at equal intervals on the surface 2a of the glass substrate 2. It

According to the above manufacturing method, the dispersed droplet lowering device 1
By changing the coating width when the ultrafine particle dispersion liquid 4 is dropped and applied onto the surface 2a of the glass plate 2,
Since the width of the linear body formed on the surface 2a portion of the can be arbitrarily adjusted, for example, an extremely fine linear body of 500 Å or less can be easily formed linearly over a wide area, and the insertion loss is small.
A large-area polarizer can be easily manufactured. The linear body formed on the surface 2a of the glass plate 2 by this manufacturing method adheres well to the glass plate 2 by the firing treatment, so that the linear body does not easily peel off from the glass plate 2 and the conventional grid is used. There is no possibility that the linear body will be deformed and its function will be impaired as in the case of the type polarizer. Therefore, the polarizer manufactured by this manufacturing method always exhibits good polarization characteristics. The function as a polarizer can be exhibited even when the metal or semiconductor particles in the ultrafine particle dispersion liquid 4 are not continuous by firing. Further, by adding Pb to the ultrafine particle dispersion liquid 4, the adhesion strength of the linear body to the glass plate 2 can be further increased. This is the added P
It is considered that the element b reacts with the glass to increase the adhesion.

[0012]

EXAMPLES Next, examples of the present invention will be described.

Ultrafine particle dispersion 4 in which ultrafine gold (Au) particles having an average particle diameter of 35Å are dispersed in α-terpineol was diluted with toluene to a gold concentration of about 20% by weight. After the diluted ultrafine particle dispersion liquid 4 was dropped onto the surface 2a of the glass plate 2 having an area of 144 cm ² (length 12 cm, width 12 cm) and a thickness of 0.5 mm by using the above dispersion droplet dropping device 1,
The glass plate 2 was put in an electric furnace and heated at a temperature of 300 ° C. for 15 minutes to form a linear body made of ultrafine gold particles, that is, a gold wire, on the surface 2 a of the glass plate 2. The width of the gold wire is 200
Å, the interval was 1 μm. Even when the gold wire portion on the surface 2a of the glass plate 2 was rubbed with a finger, the gold wire was stable without peeling.

Two pieces of the above-mentioned 12 cm × 12 cm size polarizer were prepared and the optical characteristics were measured. The degree of polarization (ρ)
Is 99.997%, which is a sufficiently good characteristic as compared with 99.67% of film-type polarizers currently on the market. The single substance transmittance was 94%, which was more than double that of the film type polarizer of 40%. Further, the ratio (Y _C / Y) of the orthogonal transmittance (Y _C ) and the parallel transmittance (Y _P ).
_P ) was 8500, which was a sufficiently large value as compared with 310 of the film-type polarizer. The insertion loss was 6%, which was a good result of 10% or less. According to the above manufacturing method, a polarizer of about A4 size can be easily prepared, and theoretically, a polarizer having a larger area can be prepared. In the above examples, only the measurement results using the Au ultrafine particle dispersion are shown.
Even when a polarizer is formed by using an ultrafine particle dispersion liquid of another metal or alloy or semiconductor, it is possible to obtain the same excellent optical characteristics and the adhesive strength of the linear body to the glass plate 2 as described above.

[0015]

As described above, according to the method for manufacturing a polarizer according to the present invention, the width of the coating liquid when the ultrafine particle dispersion liquid is dropped and coated on the surface of the supporting plate is changed. Since the width of the linear body formed on the surface part of the can be adjusted arbitrarily, for example, an ultrafine linear body of 500 Å or less can be easily formed linearly over a wide area, and the insertion loss is small.
A large-area polarizer can be easily manufactured. The linear body formed on the surface portion of the support plate by this manufacturing method adheres well to the plate by the firing treatment, so the linear body does not easily come off from the support plate, and the linear body deforms and functions. Is never compromised. Therefore, the polarizer manufactured by this manufacturing method always exhibits good polarization characteristics.
Further, the polarizer according to the present invention is a so-called grid type in which a plurality of linear bodies made of a metal or a semiconductor are linearly formed at equal intervals to each other on a surface portion of a support transparent to visible light. Adhesion between the linear body and the support plate is improved by adopting a polarizer having a structure of a polarizer, which is formed by dropping and coating the ultrafine particle dispersion liquid on the surface of the support plate as the linear body. Since the linear body does not easily peel off from the support plate, it is possible to easily cope with a large area.

[Brief description of drawings]

FIG. 1A is a schematic front view showing an example of an embodiment of an ultrafine particle dispersion liquid coating step, which is one step in manufacturing a polarizer by the manufacturing method of the present invention, and FIG. FIG.

FIG. 2 is a schematic plan view showing an example of an embodiment of an ultrafine particle dispersion liquid coating step, which is one step in manufacturing a polarizer by the manufacturing method of the present invention.

FIG. 3 is a perspective view showing an example of a structure of a conventional polarizer.

[Explanation of symbols]

 1 Dispersion Droplet Lowering Device 2 Glass Substrate (Support Plate) 2a Surface 3 Substrate Placement Part 4 Ultrafine Particle Dispersion Liquid 5 Container 6 Needle 6a Needle Point

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[Procedure amendment]

[Submission date] June 21, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 3

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

In the above-mentioned polarizer and the method for producing the same according to the present invention, it is most preferable that the particle size is 50 Å or less. The width of the linear body is, for example, 500 Å or less as shown in claim 2 and its variation is 20%.
It is preferably within the range. Further, the interval between the linear bodies is 0.5 to 2.0 μm and the variation is 20%.
It is preferably within the range. The width of the linear body is 500Å
The larger the value, the larger the absorption in the visible light region. If the distance between the linear bodies is larger than 2.0 μm, the degree of polarization in the visible light region is small, and if it is smaller than 0.5 μm, the absorption is too large.

Claims (4)

[Claims] 1. An ultrafine particle dispersion obtained by dispersing metal or semiconductor particles having a particle size of 100Å or less in an organic solvent is linearly and evenly spaced from each other on the surface of a support plate transparent to visible light. By applying multiple rows of drops and firing,
A method for manufacturing a polarizer, wherein a plurality of linear bodies made of metal or semiconductor are formed linearly and at equal intervals on the surface of the support plate. 2. The method for manufacturing a polarizer according to claim 1, wherein the width of the linear body is 500 Å or less. 3. A polarizer formed by linearly forming a plurality of linear bodies made of a metal or a semiconductor on a surface portion of a support transparent to visible light at equal intervals. The particles are obtained by dropping and coating an ultrafine particle dispersion liquid obtained by dispersing metal or semiconductor particles having a particle size of 500 or less in an organic solvent on the surface of the support on the surface of the support plate.
A polarizer characterized by being fired. 4. The polarizer according to claim 3, wherein the width of the linear body is 500 Å or less.