# US 2008/0186576 A1 · Polarizing element and liquid crystal projector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0186576 A1 - Document ID: US20080186576A1 - Status: Published application - Kind: A1 - Application number: 12/026,434 - Filed: 2008-02-05 - Published: 2008-08-07 - Earliest claimed: 2007-02-06 - Assignees: Sony Corporation - Inventors: Akio Takada - Web page: https://patentgrep.com/patent/US20080186576A1 ## CPC - G02B 5/3025: {Polarisers, i.e. arrangements capable of producing a definite output polarisation state from an unpolarised input state (G02B5/3008, G02B5/3016 take precedence)} - G02F 1/133548: {Wire-grid polarisers} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A polarizing plate having a desired extinction ratio in a visible light region and light resistance against strong light, and a liquid crystal projector using the above polarizing plate are provided. In 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 shape anisotropic properties in which a diameter of the inorganic particles in the disposed direction is long and a diameter in a direction perpendicular thereto is short. ## Claims ### Claim 1 A polarizing element comprising: 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 shape anisotropic properties in which a diameter in a disposed direction is long and a diameter in a direction perpendicular thereto is short. ### Claim 2 (depends on 1) The polarizing element according to claim 1, wherein as an optical constant of the first inorganic particle layers, an optical constant 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. ### Claim 3 (depends on 2) The polarizing element according to claim 2, wherein as the optical properties of the first inorganic particle layers, the refractive index of the first inorganic particles in the disposed direction is larger than that of the first inorganic particles in the direction perpendicular thereto, and 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. ### Claim 4 (depends on 1) The polarizing element according to claim 1, wherein the first inorganic particle layers are formed by an oblique sputtering method. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 1) The polarizing element according to claim 1, wherein the first inorganic particle layers have a thickness of 200 nm or less. ### Claim 8 (depends on 1) The polarizing element according to claim 1, further comprising 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. ### Claim 9 (depends on 1) The polarizing element according to claim 1, further comprising: 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 first inorganic particle layers are provided on the first dielectric layers at positions corresponding to those of the strip-shaped thin films. ### Claim 10 (depends on 9) The polarizing element according to claim 9, wherein the 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 substrate so that the direction of the inorganic particles corresponds to the disposed direction of the first inorganic particles. ### Claim 11 (depends on 9) The polarizing element according to claim 9, further comprising second inorganic particle layers in each of which second inorganic particles are linearly disposed; and 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. ### Claim 12 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 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 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. ### Claim 13 (depends on 1) 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. ### Claim 14 A liquid crystal projector comprising: a lamp; a liquid crystal panel; and the 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 shape anisotropic properties in which a diameter in a disposed direction is long and a diameter in a direction perpendicular thereto is short.