# US 5,350,498 A · Inducing tilted perpendicular alignment in liquid crystals > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,498 A - Document ID: US5350498A - Status: Granted - Kind: A - Application number: 08/034,626 - Filed: 1993-03-22 - Granted: 1994-09-27 - Earliest claimed: 1991-06-14 - Assignees: Hughes Aircraft Company - Inventors: Willis H. Smith, Jr.; Hugh L. Garvin; Klaus Robinson; Leroy J. Miller - Web page: https://patentgrep.com/patent/US5350498A ## CPC - G02F 1/133734: {by obliquely evaporated films, e.g. Si or SiO2 films} - G02F 1/133719: {with coupling agent molecules, e.g. silane} - C09K 2323/021: Inorganic, e.g. glass or silicon oxide - G02F 1/133742: {for homeotropic alignment} - Y10T 428/259: Silicic material - Y10T 428/263: Coating layer not in excess of 5 mils thick or equivalent - 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 - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A substrate (20) is treated prior to use to induce a near-perpendicular orientation of a liquid crystal director (26) relative to the substrate. A layer of silica (38) is deposited upon the substrate (20) by in-line magnetron sputtering as the substrate (20) is moved past the sputtering target (78), and the silica-coated substrate (20) is thereafter treated with a long-chain alcohol. The alcohol-treated substrate (20) is covered with a layer of liquid crystal (22), the director (26) of the liquid crystal (22) assuming a field-off state tilted about 1-3 degrees from the perpendicular toward an azimuthal direction (30) parallel to the direction of movement of the substrate (20) during deposition. ## Claims ### Claim 1 A method for preparing a treated substrate to produce tilted perpendicular alignment of a liquid crystal on the substrate, wherein the liquid crystal is comprised of elongated molecules whose combined long molecular axes define a macroscopic director, with both tilt angle and tilt direction of the director being substantially uniform, predictable, and controllable, comprising the steps of: moving a substrate past a source of silica; depositing a layer of silica on the substrate from the source of silica as the substrate is moved past the source during deposition; treating the silica-coated substrate with a long-chain alcohol; and covering the substrate with a layer of liquid crystal, the director at all points across the surface of the substrate having an azimuthal direction that is substantially uniform, such that projection of the director onto the substrate surface is everywhere approximately parallel. ### Claim 2 (depends on 1) The method of claim 1, wherein the substrate is made of glass or quartz. ### Claim 3 (depends on 1) The method of claim 1, wherein the substrate is a liquid crystal light valve substrate. ### Claim 4 (depends on 1) The method of claim 1, wherein the substrate has an electrically conductive coating thereupon prior to the step of moving. ### Claim 5 (depends on 1) The method of claim 1, wherein the step of depositing ls accomplished in a plurality of passes of the substrate past the source. ### Claim 6 (depends on 1) The method of claim 1, wherein the step of depositing is accomplished in a single pass of the substrate past the source. ### Claim 7 (depends on 1) The method of claim 1, wherein the step of treating is accompllshed with the substrate at a temperature of from about 120.degree. C. to about 160.degree. C. ### Claim 8 (depends on 1) The method of claim 1, wherein the alcohol is selected from the group consisting of a long chain aliphatic alcohol of the form CH.sub.3 (CH.sub.2).sub.n CH.sub.2 OH, where n ranges from about 4 to about 28, 2-hexadecanol, 1,2-octadecanediol and cholesterol. ### Claim 9 (depends on 8) The method of claim 8, wherein an amine is mixed with the alcohol. ### Claim 10 (depends on 8) The method of claim 8, wherein said long chain aliphatic alcohol is selected from the group consisting of 1-decanol, 1-dodecanol, 1-hexadecanol, 1-octadecanol, 1-eicosanol, and 1-triacontanol. ### Claim 11 (depends on 1) The method of claim 1, wherein the source of silica includes a sputtering target. ### Claim 12 (depends on 1) The method of claim 1, wherein the source of silica is a magnetron sputtering target. ### Claim 13 (depends on 1) The method of claim 1 wherein the substrate is substantially uniformly moved past the source of silica in linear motion. ### Claim 14 A method for preparing a liquid crystal device havig a tilted perpendicular alignment of liquid crystal on the substrate, wherein the liquid crystal is comprised of elongated molecules whose combined long molecular axes define a macroscopic director, with both tilt angle and tilt direction of the director being substantially uniform, predictable, and controllable, comprising the steps of: moving a substrate past a source of silica; depositing a layer of silica on the substate by magnetron in-line sputtering from the source of silica as the substrate is moved past the source during deposition; treating the silica-coated substrate with a long chain alcohol; and covering the alcohol-treated substrate with a layer of liquid crystal, the director at all points across the surface of the substrate having an an azimuthal direction that is substantially uniform, such that projection of the director onto the substrate surface is everywhere approximately parallel. ### Claim 15 (depends on 14) The method of claim 14, wherein the substrate is glass coated with a layer of an electrically conductive material thereon. ### Claim 16 (depends on 14) The method of claim 14, wherein the thickness of the layer of silica is from about 12 Angstroms to about 3000 Angstroms. ### Claim 17 (depends on 14) The method of claim 14, wherein the liquid crystal is selected from the group consisting of a nematic, a cholesteric, and a smectic liquid crystal. ### Claim 18 (depends on 14) The method of claim 14 wherein the substrate is a liquid crystal light valve substrate. ### Claim 19 (depends on 14) The method of claim 14 wherein the substrate is substantially uniformly moved past the source of silica in linear motion. ### Claim 20 A method for preparing a treated substrate to produce tilted particular alignment of a liquid crystal on the substrate, wheein the liquid crystal is comprised of elongated moelcules whose combiend long molecular axes define a macroscopic director, with both tilt angle and tilt direciton of the director being substantilly uniform, predictable, and controllable, comprising the steps of: moving a substrate past a source of silica; depositing a layer of silica on the substrate from the source of silica as the substrate is moved past the source during deposition; and covering the substrate with a layer of liquid crystal having the property of spontaneously aligning with the director substantially perpendicular to the substrate surface, the director at all points across the surface of the substrate having an azimuthal direction that is substantially uniform, such that projection of the director onto the substrate surface is everywhere approximately parallel. ### Claim 21 (depends on 20) The method of claim 20 wherein said substrate is a member selected from the group consisting of glass, quartz, and a liquid crystal light valve substrate. ### Claim 22 (depends on 20) The method of claim 20 wherein said substrate is provided with an electrically conductive coating prior to the step of moving. ### Claim 23 (depends on 20) The method of claim 20 wherein the step of depositing is accomplished in at least one pass of said substrate past said source. ### Claim 24 (depends on 20) The method of claim 20 wherein the step of treating is accomplished with said substrate at a temperature of about 120.degree. to 160.degree. C.