JP4559998B2 - Polarizer - Google Patents

Description

  The present invention relates to a polarizing plate in which polarizers that transmit only a specific polarization component are arranged on a glass plate.

  The polarizing plate is usually made of a crystal having directionality, and transmits only the polarization component of light that vibrates in one direction. Usually, this polarizing plate is applied to a liquid crystal display device such as a so-called projector.

  When producing a polarizing plate, a polarizer is produced by first drying a polyvinyl alcohol (PVA) film through a dyeing process, a crosslinking process, and a stretching process. On top of that, a polarizer protective film such as a triacetyl cellulose (TAC) film is bonded. Furthermore, a protective layer, an optical layer, an adhesive layer, and the like for the purpose of protecting the polarizing plate, imparting functions, or convenience for lamination are appropriately laminated on both surfaces.

  As a polarizing plate, a so-called wire grid type in which a wire grid is used as a polarizer has been proposed in addition to a technique for separating a polarized light component using a dye as described above.

  This wire grid type polarizing plate embeds micron-sized fine metal wires in a glass plate. As a result, when a polarization component parallel to the long axis direction of the metal thin wire is incident, electrons in the metal thin wire vibrate according to the light of the polarization component. Since the polarization direction of the light coincides with the vibration direction of the electrons in the fine metal wire, the light whose polarization direction is the same as the major axis direction of the fine metal wire is gradually attenuated by the vibration of the electrons. . As a result, the transmission of the polarization component parallel to the major axis direction of the fine metal wire is suppressed, and only the polarization component of the light orthogonal to the major axis direction is transmitted.

In recent years, for example, a wire grid polarizer as shown in Patent Document 1 has been proposed.
JP 2002-328234 A

  However, many of the above-mentioned conventional polarizing plates focus on the production cost and the polarization efficiency, and it is only necessary to be able to arrange them in the liquid crystal back panel. . However, in recent years, with the progress of ultra-miniaturization of various devices including notebook computers and the like, it is necessary to make the polarizing plate ultra-miniaturized to a nanometer size. In particular, it is considered that future applications can be expanded by forming a polarizing plate that can be bent by configuring the thickness to a nanometer size.

  Therefore, the present invention has been devised in view of the above-described problems, and an object of the present invention is to provide a polarizing plate that can be downsized to a nanometer size.

  In order to solve the above-described problem, the present inventor separates the first metal thin wire connected to the second metal fine wire and the start end and the end of the third metal fine wire from each other to thereby separate the first metal thin wire. Note that it is possible to create an electric field between the fine line and the third metal line of sight, thereby rotating the electric field direction and thus rotating the polarization direction of the light incident on the polarizer, A polarizing plate having the following constitution was invented.

  That is, the polarizing plate according to claim 1 is a polarizing plate in which polarizers that transmit only a specific polarization component are arranged in a glass plate, and the first layer and the second layer in the thickness direction from the emission side to the incident side. And a glass plate divided into a third layer, and a polarizer disposed in the glass plate, wherein the polarizer extends from the first layer of the glass plate as a starting end. A thin wire, a second metal thin wire having one end connected to the first metal thin wire through the second layer and disposed in the third layer, and one end being the other end of the second metal thin wire Are connected to each other via the second layer and extend to the end in the first layer, and the first metal thin wire to the third metal thin wire are in the major axis direction. Are configured to have a size of 1 μm or less and are substantially parallel to each other. Wherein the spaced apart in the vertical direction with respect to the direction.

  The polarizing plate according to claim 2 is the polarizing plate according to claim 1, wherein the second thin metal wire takes out a magnetic field component of light in a polarization direction substantially parallel to the current as a current, and the first metal An electric field is created between the thin wire and the third metal wire based on the current extracted by the second metal wire, and is substantially perpendicular to the second metal wire based on the created electric field. It is characterized by emitting light in the polarization direction.

  In the present invention having the above-described configuration, it is possible to provide a polarizing plate that can be downsized to a nanometer size. For this reason, it becomes possible to cope with the progress of ultra-miniaturization of various devices such as notebook personal computers and the like, and since it can be a foldable polarizing plate, it can be used for various applications. .

  Hereinafter, as a best mode for carrying out the present invention, a polarizing plate in which a polarizer that transmits only a specific polarization component is arranged on a glass plate will be described in detail with reference to the drawings.

  A polarizing plate 1 to which the present invention is applied includes, for example, as shown in FIG. 1, a glass plate 11 and a polarizer 12 arranged in the glass plate 11.

  The glass plate 11 is divided into a first layer 13, a second layer 14, and a third layer 15 in the thickness direction from the exit side to the entrance side. The first layer 13 to the third layer 15 are made of the same material, and these layers are not separated from each other. That is, the first layer 13 to the third layer 15 are defined as one index when one glass plate is divided into three stages in the thickness direction. Incidentally, the first layer 13 to the third layer 15 may be formed separately from each other and then laminated together to form a single glass plate 11.

  The polarizer 12 is composed of a thin metal wire. In the microscopic observation at the nano level, the polarizer 12 is configured such that a plurality of rectangular parallelepiped blocks are connected to each other as shown in FIG. That is, the polarizer 12 has a shape similar to a so-called Helmholtz coil. The metal material constituting the polarizer 12 is, for example, gold, silver, aluminum or copper. Incidentally, on the glass plate 11, the polarizers 12 are arranged periodically or randomly to some extent in the vertical and horizontal directions. The interval between the polarizers 12 is set to be equal to or longer than the wavelength λ of incident light.

  The polarizer 12 includes a first metal thin wire 21 extending from the first layer 13 of the glass plate 11 to the end 31 as a start end 30, and a second end 32 connected to the end 31 of the first metal thin wire 21. The second metal thin wire 22 connected through the layer 14 and disposed in the third layer 15 and the end 34 are connected to the end 33 of the second metal thin wire 22 through the second layer 14. And a third fine metal wire 23 extending to the end 35 in the first layer 13.

  The first metal thin wire 21 to the third metal thin wire 23 are substantially parallel to each other and are substantially parallel to one polarization direction x of the light. The start end 30 and the end end 35 are separated from each other in the direction y perpendicular to the polarization direction x. That is, the first metal fine wire 21, the second metal fine wire 22, and the third metal fine wire 23 are formed in the order shifted in the direction y.

  In addition, a fourth metal wire 24 and a fifth metal wire 25 are interposed between the end 31 of the first metal wire 21 and the end 32 of the second metal wire 22. Also good.

  The fourth metal thin wire 24 is connected to the first metal thin wire 21 and is erected in the vertical direction from the first layer 13 to the third layer 15. In addition, the fifth fine metal wire 25 is extended in the third layer 13 in the direction y, and is connected to the end portion 32 of the second fine metal wire 22.

  In addition, a sixth metal thin wire 26 and a seventh metal thin wire 27 are interposed between the end 33 of the second metal thin wire 22 and the end 34 of the third metal thin wire 23. Also good.

  The sixth metal thin wire 26 extends in the third layer 13 in the direction y. The seventh thin metal wire 27 is erected in the vertical direction from the third layer 13 to the first layer 11.

  In addition, these 4th metal fine wires 24-7th metal fine wire 27 are not limited to passing through the process mentioned above, You may make it take any processes. For example, the end portion 31 of the first fine metal wire 21 and the end portion 32 of the second fine metal wire 22 may be connected in a straight line or may be connected in a curved line.

  Each of the metal thin wires 21 to 27 is configured to have a nanometer size (1 μm or less) in the major axis direction. The fine metal wires 21 to 27 may be produced separately from each other or may be produced at the same time, but in any case, they are connected to each other to form one coil wire. The upper limit value of the length in the major axis direction of the thin metal wires 21 to 27 is set to the wavelength λ.

  For example, as shown in FIG. 2, when light having a polarization direction y (the electric field direction of light is y and the magnetic field direction of light is x) is incident on the polarizing plate 1 having such a configuration. Most of the light passes through the polarizing plate 1.

  On the other hand, when light having a polarization direction x (the electric field direction of light is x and the magnetic field direction of light is y) is incident, the polarizer 12 functions as a so-called coil. That is, when light in the magnetic field direction y is incident, the magnetic field component is converted into an electric current by the polarizer 12 as the coil. That is, the second thin metal wire 22 takes out current from light in the magnetic field direction y perpendicular to the major axis direction.

  Based on the current taken out by the second thin metal wire 22, a current flows along the first thin metal wire 21 to the third thin metal wire 23. As a result, a potential is generated between the first metal thin wire 21 and the third metal thin wire 23, and an electric field w in the direction of the arrow is created. Light is emitted by the electric field w, and the polarization direction of the emitted light is the y direction, which is perpendicular to the polarization direction x of the incident light. That is, light having a polarization direction y substantially perpendicular to the polarization direction x of incident light is emitted from the polarizer 12.

  In other words, in the polarizer 12, the first end 30 and the end 35 of the first thin metal wire 21 and the third thin metal wire 23 connected to the second thin metal wire 22 are separated from each other. For this reason, an electric field can be created between the 1st metal fine wire 21 and the 3rd metal visual line 23, and an electric field direction can be rotated by this, and also the polarization direction of the light which injected into the polarizer 12 by extension. It becomes possible to convert x into the polarization direction y.

  As described above, in the present invention, when the light with the polarization direction x is incident, the light is transmitted as it is, and when the light with the polarization direction y is incident, the polarizer 12 as a coil is used. By rotating the polarization direction in the x direction, it is possible to assume a function as a so-called polarizing plate.

  In the present invention, since the polarizer 12 itself can be configured in a nanometer size, it can be miniaturized, and it can cope with the progress of ultra miniaturization of various devices such as notebook personal computers. It becomes possible. Moreover, since it can be set as the polarizing plate which can be bend | folded, it becomes possible to utilize for various uses.

  Note that the distance in the direction x between the starting end 30 of the first thin metal wire 21 and the terminal end 35 of the third thin metal wire 23 is preferably within a range of λ / 4. That is, the magnetic field z can be effectively generated by providing a certain overlap region in the direction x between the first metal thin wire 21 and the third metal thin wire 23. .

  First, the first layer 13 in which the first metal thin wire 21 and the third metal thin wire 23 are embedded, the second metal thin wire 23, the fifth metal thin wire 25, and the sixth metal thin wire 26 are embedded. A third layer 15 was produced. The first layer 13 and the third layer 15 can be manufactured by using general photolithography, processing by an electron beam, or the like, and a specific process is not necessary.

  Next, the 2nd layer 14 which embedded the 4th metal fine wire 24 and the 7th metal fine wire 27 was produced. The second layer 14 was produced using a so-called nanoimprint technique. In addition, the metal which comprises each metal fine wire 21-27 was aluminum.

  Next, the first layer 13 to the third layer 15 were bonded together to form a single glass plate 11, and the polarizing plate 1 was completed. The size of each thin metal wire 21 to 27 produced in this example is as shown in FIG.

  When light having a polarization direction y was incident on the produced polarizing plate 1, the transmittance was 90%. Next, when light having a polarization direction x was incident on the produced polarizing plate 1, it was converted to light having a polarization direction y, and the transmittance was 30%. That is, when non-polarized light is incident, the conversion efficiency in the polarization direction y is considered to be (90% + 30%) / 2 = 60%. The extinction ratio is 3 dB.

It is a perspective view for demonstrating the structure of the polarizing plate to which this invention is applied. It is a figure shown about the example when the light of the polarization direction y injects.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polarizing plate 11 Glass plate 12 Polarizer 21 1st metal wire 22 2nd metal wire 23 3rd metal wire

Claims (2)

In a polarizing plate in which polarizers that transmit only a specific polarization component are arranged in a glass plate,
A glass plate divided into a first layer, a second layer, and a third layer in the thickness direction from the exit side to the entrance side;
A polarizer disposed in the glass plate,
The polarizer is
A first fine metal wire extending from the first layer of the glass plate as a starting end;
A second metal wire having one end connected to the first metal wire through the second layer and disposed in the third layer;
A third metal wire having one end connected to the other end of the second metal wire via the second layer and extending to the end in the first layer;
The first metal thin wire to the third metal thin wire are configured so that the major axis direction has a size of 1 μm or less and is substantially parallel to each other. A polarizing plate characterized by being spaced apart. The second thin metal wire takes out a magnetic field component of light having a polarization direction substantially parallel to the second metal wire as a current,
An electric field is created between the first thin metal wire and the third thin metal wire based on the current extracted by the second thin metal wire,
The polarizing plate according to claim 1, wherein light having a polarization direction substantially perpendicular to the second thin metal wire is emitted based on the generated electric field.

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