Polarizing element and liquid crystal projector

Abstract

A polarizing plate having a desired extinction ratio in a visible light region and light resistance against intense light, and a liquid crystal projector using the above polarizing plate are provided. A polarizing element includes a substrate transparent to visible light, and inorganic particle layers in each of which inorganic particles are linearly disposed, the inorganic particle layers being disposed on the substrate at predetermined intervals to form a wire grid structure, the inorganic particles each have an elliptical shape having a major axis of the inorganic particles in the disposed direction and minor axis in a direction perpendicular thereto.

The invention is claimed as follows: 
     
       1. A polarizing element comprising:
 a first polarizing element including a first substrate transparent to visible light, and   first inorganic particle layers in each of which first inorganic particles are linearly disposed on the first substrate, the first inorganic particle layers being disposed on the first substrate at predetermined intervals to form a wire grid structure,   wherein the first inorganic particles each have an elliptical shape with a major axis in a disposed direction and a minor axis in a direction perpendicular thereto,   wherein the first polarizing element further includes convex portions, which are made of a material transparent to visible light and which extend in one direction, provided on the first substrate,   wherein the first inorganic particle layers are each provided on a top part or at least one of sidewall parts of each of the convex portions; and   a second polarizing element including a second substrate transparent to visible light, and   second inorganic particle layers in each of which second inorganic particles are linearly disposed on the second substrate, the second inorganic particle layers being disposed on the second substrate at predetermined intervals to form a wire grid structure,   wherein the second inorganic particles each have shape anisotropic properties in which a diameter in a disposed direction is long and a diameter in a direction perpendicular thereto is short,   wherein the second polarizing element further includes reflection layers of strip-shaped thin films, which are made of a metal and which extend in one direction, provided on the second substrate at predetermined intervals; and first dielectric layers provided on the reflection layers,   wherein the second inorganic particle layers are provided on the first dielectric layers at positions corresponding to those of the strip-shaped thin films, and   wherein the first and second substrates are adhered to each other at rear surfaces thereof.   
     
     
       2. The polarizing element according to  claim 1 ,
 wherein a refractive index of the first inorganic particles in the disposed direction is larger than that of the first inorganic particles in the direction perpendicular to the disposed direction.   
     
     
       3. The polarizing element according to  claim 2 ,
 wherein an extinction coefficient of the first inorganic particles in the disposed direction is larger than that of the first inorganic particles in the direction perpendicular thereto.   
     
     
       4. The polarizing element according to  claim 1 ,
 wherein the first inorganic particle layers are formed by an oblique sputtering method.   
     
     
       5. The polarizing element according to  claim 1 ,
 wherein the first inorganic particles include a single element selected from the groups consisting of: Al, Ag, Cu, Au, Mo, Cr, Ti, W, Ni, Fe, Si, Ge, Te, and Sn, an alloy thereof, or a silicide semiconductor material.   
     
     
       6. The polarizing element according to  claim 1 ,
 wherein the first inorganic particles include a semiconductor material having a bandgap energy of 3.1 eV or less.   
     
     
       7. The polarizing element according to  claim 1 ,
 wherein the first inorganic particle layers have a thickness of 200 nm or less.   
     
     
       8. The polarizing element according to  claim 1 ,
 wherein the second substrate is processed by a rubbing treatment so that the direction of the rubbing treatment corresponds to the disposed direction of the first inorganic particles,   the polarizing element further comprising antireflection layers of inorganic particles having shape anisotropic properties, the antireflection layers being provided on the surface of the second substrate so that the direction of the inorganic particles corresponds to the disposed direction of the first inorganic particles.   
     
     
       9. The polarizing element according to  claim 1 ,
 further comprising   second dielectric layers, the second inorganic particle layers and the second dielectric layers forming laminates,   wherein at least one of the laminates is provided on each of the first inorganic particle layers.   
     
     
       10. The polarizing element according to  claim 1 , further comprising a polarizing element protective layer transparent to light in a service bandwidth as an outermost surface. 
     
     
       11. A liquid crystal projector comprising:
 a lamp;   a liquid crystal panel; and   a polarizing element including a substrate transparent to visible light; and   first inorganic particle layers in each of which first inorganic particles are linearly disposed on the substrate, the first inorganic particle layers being disposed on the substrate at predetermined intervals to form a wire grid structure,   wherein the first inorganic particles each have an elliptical shape with a major axis in a disposed direction and a minor axis in a direction perpendicular thereto,   wherein the first polarizing element further includes convex portions, which are made of a material transparent to visible light and which extend in one direction, provided on the first substrate,   wherein the first inorganic particle layers are each provided on a top part or at least one of sidewall parts of each of the convex portions; and   a second polarizing element including a second substrate transparent to visible light, and   second inorganic particle layers in each of which second inorganic particles are linearly disposed on the second substrate, the second inorganic particle layers being disposed on the second substrate at predetermined intervals to form a wire grid structure,   wherein the second inorganic particles each have shape anisotropic properties in which a diameter in a disposed direction is long and a diameter in a direction perpendicular thereto is short,   wherein the second polarizing element further includes reflection layers of strip-shaped thin films, which are made of a metal and which extend in one direction, provided on the second substrate at predetermined intervals; and first dielectric layers provided on the reflection layers,   wherein the second inorganic particle layers are provided on the first dielectric layers at positions corresponding to those of the strip-shaped thin films, and   wherein the first and second substrates are adhered to each other at rear surfaces thereof.   
     
     
       12. A polarizing element comprising:
 a substrate;   a plurality of reflection layers provided on the substrate, the plurality of reflection layers extend in a first direction perpendicular to the substrate;   a dielectric layer provided on at least a portion of at least one of the plurality of reflection layers, the dielectric layer includes a dielectric layer material selected from the group consisting of SiO2, Al2O3, MgF2 and combinations thereof; and   a first inorganic particle layer including a plurality of first inorganic particles,   wherein the first inorganic particle layer is disposed on a top surface of the dielectric layer.   
     
     
       13. The polarizing element according to claim 12, further comprising a protective layer formed as an outermost surface of the polarizing element. 
     
     
       14. The polarizing element according to claim 12, wherein the plurality of reflection layers include a strip-shaped thin film. 
     
     
       15. The polarizing element according to claim 12, wherein the dielectric layer is formed over the substrate and includes a concave-convex shape having convex portions over the plurality of reflection layers and concave portions therebetween. 
     
     
       16. The polarizing element according to claim 12, wherein the first inorganic particles include at least one of Al, Ag, Cu, Au, Mo, Cr, Ti, W, Ni, Fe, Si, Ge, Te, Sn, an alloy thereof, and a silicide semiconductor material. 
     
     
       17. The polarizing element according to claim 12, wherein the first inorganic particles include a semiconductor material having a bandgap energy of 3.1 eV or less. 
     
     
       18. The polarizing element according to claim 12, wherein the first inorganic particle layer has a thickness of 200 nm or less. 
     
     
       19. The polarizing element according to claim 12, wherein the polarizing element includes a wire grid structure. 
     
     
       20. The polarizing element according to claim 12, wherein a first refractive index of the first inorganic particles in the first direction is smaller than a second refractive index of the first inorganic particles in a second direction perpendicular to the first direction. 
     
     
       21. The polarizing element according to claim 20, wherein a first extinction coefficient of the first inorganic particles in the first direction is smaller than a second extinction coefficient of the first inorganic particles in the second direction. 
     
     
       22. The polarizing element according to claim 12, wherein the substrate has a concave-convex member formed thereon, and the concave-convex member includes a pitch of 0.5 μm or less, a width of 0.25 μm or less, and a depth of 1 nm or more. 
     
     
       23. The polarizing element according to claim 22, further comprising a second inorganic particle layer including a plurality of second inorganic particles, wherein the second inorganic particle layer is disposed on the concave-convex member. 
     
     
       24. The polarizing element according to claim 12, further comprising antireflection layers being provided between the substrate and the reflection layers. 
     
     
       25. The polarizing element according to claim 12, wherein the plurality of reflection layers spaced apart from each other at a predetermined interval on the substrate. 
     
     
       26. A liquid crystal projector comprising:
 a liquid crystal panel, an incident polarizing plate, and an emission polarizing plate;   wherein the emission polarizing plate including:
 a substrate; 
 a plurality of reflection layers provided on the substrate, the plurality of reflection layers extend in a first direction perpendicular to the substrate; 
 a dielectric layer disposed on at least a portion of at least one of the plurality of reflection layers, the dielectric layer includes a dielectric layer material selected from the group consisting of SiO2, Al2O3, MgF2 and combinations thereof; and 
 a first inorganic particle layer including a plurality of first inorganic particles, 
 wherein the first inorganic particle layer is disposed on a top surface of the dielectric layer. 
   
     
     
       27. The liquid crystal projector according to claim 26, wherein the emission polarizing plate includes an inorganic polarizing plate. 
     
     
       28. The liquid crystal projector according to claim 26, wherein the dielectric layer is formed over the substrate and includes a concave-convex shape having convex portions over the plurality of reflection layers and concave portions therebetween. 
     
     
       29. The liquid crystal projector according to claim 26, further comprising a protective layer formed as an outermost surface of the emission polarizing plate. 
     
     
       30. The liquid crystal projector according to claim 26, wherein the first inorganic particles include at least one of Al, Ag, Cu, Au, Mo, Cr, Ti, W, Ni, Fe, Si, Ge, Te, Sn, an alloy thereof, and a silicide semiconductor material. 
     
     
       31. The liquid crystal projector according to claim 26, wherein the first inorganic particle layer has a thickness of 200 nm or less. 
     
     
       32. The liquid crystal projector according to claim 26, wherein the plurality of reflection layers spaced apart from each other at a predetermined interval on the substrate. 
     
     
       33. A liquid crystal display comprising:
 a liquid crystal panel;   a polarizing plate;   wherein the polarizing plate including:
 a substrate; 
 a plurality of reflection layers provided on the substrate, the plurality of reflection layers extend in a first direction perpendicular to the substrate; 
 a dielectric layer provided on at least a portion of at least one of the plurality of reflection layers, the dielectric layer includes a dielectric layer material selected from the group consisting of SiO2, Al2O3, MgF2 and combinations thereof; and 
 a first inorganic particle layer including a plurality of first inorganic particles, 
 wherein the first inorganic particle layer is disposed on a top surface of the dielectric layer. 
   
     
     
       34. The liquid crystal display according to claim 33, wherein the dielectric layer is formed over the substrate and includes a concave-convex shape having convex portions over the plurality of reflection layers and concave portions therebetween.