# US 11,442,352 B2 · Lighting system and projection apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,442,352 B2 - Document ID: US11442352B2 - Status: Granted - Kind: B2 - Application number: 16/926,750 - Filed: 2020-07-12 - Published: 2021-01-21 - Granted: 2022-09-13 - Earliest claimed: 2019-07-15 - Assignees: Coretronic Corporation - Applicants: Coretronic Corporation - Inventors: Yao-Shun Lin; Hsuan-I Wu - Web page: https://patentgrep.com/patent/US11442352B2 ## CPC - G03B 21/208: {Homogenising, shaping of the illumination light} - G02B 27/286: {for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another (G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34)} - G03B 21/2013: {Plural light sources} - G03B 21/2033: {LED or laser light sources} - G03B 21/204: {using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197)} - G03B 21/2073: {Polarisers in the lamp house (peculiar to electronic spatial light modulators H04N9/3197)} - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present invention provides a lighting system, including at least one light source, a depolarization element and a light homogenization element. The at least one light source is configured to provide at least one light beam. The depolarization element is disposed on a transmission path of the at least one light beam. The depolarization element includes a first optical element, and the first optical element is provided with a first optical axis. The light homogenization element is configured to allow the at least one light beam to pass to form an illuminating light beam. The incident direction where the at least one light beam is transmitted to the first optical element is not parallel to the first light axis. The depolarization element is located between the at least one light source and the light homogenization element. In addition, projection apparatus is also provided. ## Claims ### Claim 1 A lighting system, comprising at least one light source, a depolarization element and a light homogenization element, wherein the at least one light source is configured to provide at least one light beam; the depolarization element is disposed on a transmission path of the at least one light beam; the depolarization element comprises a first optical element, and the first optical element comprises a first optical axis; the depolarization element also comprises a second optical element comprising a second optical axis, and the first optical axis is not parallel to the second optical axis; the first optical element comprises a first light entering surface and a first light exiting surface which are not parallel to each other, and the second optical element comprises a second light entering surface and a second light exiting surface which are not parallel to each other, the first light exiting surface is parallel to the second light entering surface, and the first light entering surface is parallel to the second light exiting surface; and the light homogenization element is configured to allow the at least one light beam to pass, so as to form an illuminating light beam, wherein the incidence direction where the at least one light beam is transmitted to the first optical element is not parallel to the first optical axis, and the depolarization element is located between the at least one light source and the light homogenization element. ### Claim 2 (depends on 1) The lighting system according to claim 1, wherein the depolarization element comprises a light entering surface and a light exiting surface, and the light entering surface is parallel to the light exiting surface. ### Claim 3 (depends on 1) The lighting system according to claim 1, wherein the the first light entering surface is perpendicular to the incident direction. ### Claim 4 (depends on 3) The lighting system according to claim 3, wherein the surface shape of the first light exiting surface is a geometrical shape with a symmetry axis. ### Claim 5 (depends on 1) The lighting system according to claim 1, wherein the first light entering surface is not perpendicular to the incident direction. ### Claim 6 (depends on 5) The lighting system according to claim 5, wherein the surface shape of the first light exiting surface is a geometrical shape with a symmetry axis. ### Claim 7 (depends on 1) The lighting system according to claim 1, wherein an included angle between the first optical axis and the second optical axis is between 40 degrees and 50 degrees. ### Claim 8 (depends on 1) The lighting system according to claim 1, wherein the lighting system also comprises: a focusing element, disposed on the transmission path of the at least one light beam and located between the at least one light source and the depolarization element. ### Claim 9 A lighting system, comprising at least one light source, a depolarization element and a light homogenization element, wherein the at least one light source is configured to provide at least one light beam; the depolarization element is disposed on a transmission path of the at least one light beam; the depolarization element comprises a first optical element, and the first optical element comprises a first optical axis; the light homogenization element is configured to allow the at least one light beam to pass, so as to form an illuminating light beam, wherein the incidence direction where the at least one light beam is transmitted to the first optical element is not parallel to the first optical axis, and the depolarization element is located between the at least one light source and the light homogenization element; the depolarization element also comprises a second optical element comprising a second optical axis, and the first optical axis is not parallel to the second optical axis; and the shape of the first optical element and the shape of the second optical element are in geometrical symmetry. ### Claim 10 A lighting system, comprising at least one light source, a depolarization element and a light homogenization element, wherein the at least one light source is configured to provide at least one light beam; the depolarization element is disposed on a transmission path of the at least one light beam; the depolarization element comprises a first optical element, and the first optical element comprises a first optical axis; the light homogenization element is configured to allow the at least one light beam to pass, so as to form an illuminating light beam, wherein the incidence direction where the at least one light beam is transmitted to the first optical element is not parallel to the first optical axis, and the depolarization element is located between the at least one light source and the light homogenization element; the depolarization element also comprises a second optical element comprising a second optical axis, and the first optical axis is not parallel to the second optical axis; and the material of the second optical element is different from the material of the first optical element. ### Claim 11 (depends on 1) The lighting system according to claim 1, wherein a gap is reserved between the first optical element and the second optical element. ### Claim 12 (depends on 11) The lighting system according to claim 11, wherein the first light exiting surface and the second light entering surface are respectively inclined to the first light entering surface by more than 1 degree. ### Claim 13 (depends on 1) The lighting system according to claim 1, wherein the depolarization element also comprises a connection piece, connected between the first optical element and the second optical element. ### Claim 14 (depends on 13) The lighting system according to claim 13, wherein the first light exiting surface is inclined to the first light entering surface by more than 1 degree. ### Claim 15 A projection apparatus, comprising a lighting system, at least one light valve and a projection lens, wherein the lighting system is configured to provide an illuminating light beam, the lighting system comprises at least one light source, a depolarization element and a light homogenization element; the at least one light source is configured to provide at least one light beam; the depolarization element is disposed on a transmission path of the at least one light beam; the depolarization element comprises a first optical element, and the first optical element comprises a first optical axis; the depolarization element also comprises a second optical element comprising a second optical axis, and the first optical axis is not parallel to the second optical axis; the first optical element comprises a first light entering surface and a first light exiting surface which are not parallel to each other, and the second optical element comprises a second light entering surface and a second light exiting surface which are not parallel to each other; the first light exiting surface is parallel to the second light entering surface; and the first light entering surface is parallel to the second light exiting surface; the light homogenization element is configured to allow the at least one light beam to pass, so as to form an illuminating light beam, wherein the incidence direction where the at least one light beam is transmitted to the first optical element is not parallel to the first optical axis, and the depolarization element is located between the at least one light source and the light homogenization element; the at least one light valve is disposed on a transmission path of the illuminating light beam and configured to convert the illuminating light beam into an image light beam; and the projection lens is disposed on a transmission path of the image light beam and configured to form the image light beam into a projection light beam. ### Claim 16 (depends on 15) The projection apparatus according to claim 15, wherein the depolarization element comprises a light entering surface and a light exiting surface, and the light entering surface is parallel to the light exiting surface. ### Claim 17 (depends on 15) The projection apparatus according to claim 15, wherein the first light entering surface is perpendicular to the incident direction. ### Claim 18 (depends on 15) The projection apparatus according to claim 15, wherein the first light entering surface is not perpendicular to the incident direction.