# US 8,783,886 B2 · Illumination system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,783,886 B2 - Document ID: US8783886B2 - Status: Granted - Kind: B2 - Application number: 13/169,443 - Filed: 2011-06-27 - Published: 2012-07-19 - Granted: 2014-07-22 - Earliest claimed: 2011-01-19 - Assignees: Delta Electronics, Inc. - Applicants: June-Jei Huang - Inventors: June-Jei Huang - Web page: https://patentgrep.com/patent/US8783886B2 ## CPC - F21V 5/02: of prismatic shape (F21V5/04 takes precedence) - G02B 5/26: Reflecting filters (G02B5/28 takes precedence) - G03B 21/2013: {Plural 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)} - H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)} - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - 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) - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An illumination system for use in a projection device is provided. The illumination system comprises a first light source, a second light source, an optical device, a wavelength transformer and a first dichroic mirror. The first light source and the second light source emit a first light beam and a second light beam respectively. The optical device defines a main optical axis and focuses the first light beam and the second light beam on a first focal point and a second focal point respectively, wherein the first focal point and the second focal point are disposed on two opposite sides of the main optical axis respectively. The wavelength transformer is disposed on the second focal point and transforms the second light beam into a third light beam. The first dichroic mirror is disposed between the light sources and the optical device. The first light beam and the second light beam are allowed to pass through the first dichroic mirror, and the third light beam is reflected by the first dichroic mirror. After being reflected by the first dichroic mirror, the third light beam is focused onto the first focal point. ## Claims ### Claim 1 An illumination system for use in a projection device, comprising: a first light source for emitting a first light beam; a second light source for emitting a second light beam; an optical device defining a main optical axis and focusing the first light beam and the second light beam on a first focal point and a second focal point respectively, wherein the first focal point and the second focal point are disposed on two opposite sides of the main optical axis respectively; a wavelength transformer disposed at the second focal point and transforming the second light beam into a third light beam; and a first dichroic mirror disposed between the first light source, the second light source and the optical device, wherein the first light beam and the second light beam are allowed to travel through the first dichroic mirror, and the third light beam is reflected by the first dichroic mirror; wherein the third light beam is emitted from the second focal point, sequentially through the optical device, and is then reflected to the optical device by the first dichroic mirror to be focused on the first focal point. ### Claim 2 (depends on 1) The illumination system as claimed in claim 1, further comprising a light coupling device disposed between the first light source, the second light source and the first dichroic mirror and utilized for combining and guiding the first light beam and the second light beam to the optical device. ### Claim 3 (depends on 2) The illumination system as claimed in claim 2, further comprising a third light source for emitting a fourth light beam, wherein the fourth light beam is emitted to the light coupling device, passes through the first dichroic mirror, and is focused on the first focal point by the optical device; and a first dichroic mirror disposed between the light sources and the optical device, wherein the first light beam, the second light beam and the fourth light beam are allowed to travel through the first dichroic mirror, and the third light beam is reflected by the first dichroic mirror. ### Claim 4 (depends on 3) The illumination system as claimed in claim 3, wherein the light coupling device comprises a first prism and a second prism. ### Claim 5 (depends on 4) The illumination system as claimed in claim 4, wherein the first light beam and the fourth light beam are totally reflected to the optical device by the first prism and is focused on the first focal point, and the second light beam sequentially travels through the second prism, the first prism and the optical device, and is focused on the wavelength transformer disposed at the second focal point. ### Claim 6 (depends on 4) The illumination system as claimed in claim 4, wherein the first light beam and the fourth light beam sequentially travel through the second prism, the first prism and the optical device and is focused on the first focal point, and the second light beam is totally reflected to the optical device by the first prism and is focused on the wavelength transformer disposed at the second focal point. ### Claim 7 (depends on 4) The illumination system as claimed in claim 4, wherein the first prism and the second prism are two prism arrays. ### Claim 8 (depends on 3) The illumination system as claimed in claim 3, wherein the illumination system further comprises a second dichroic mirror, the first light beam is reflected to the light coupling device by the second dichroic mirror, and the fourth light beam travels through the second dichroic mirror to the light coupling device. ### Claim 9 (depends on 3) The illumination system as claimed in claim 3, wherein the illumination system further comprises a mirror array with a plurality of mirrors, the second light source comprises a plurality of secondary light sources for emitting a plurality of secondary light beams, one part of the secondary light beams travel through the mirrors to the light coupling device, and the other secondary light beams are reflected to the light coupling device by the mirrors. ### Claim 10 (depends on 1) The illumination system as claimed in claim 1, wherein the first light beam and the second light beam are a plurality of blue light beams. ### Claim 11 (depends on 10) The illumination system as claimed in claim 10, wherein the wavelength transformer is a yellow phosphor or a green phosphor, and correspondingly, the third light beam is a yellow light beam or a green light beam. ### Claim 12 (depends on 11) The illumination system as claimed in claim 11, wherein the first light source and the second light source are a plurality of blue laser light sources. ### Claim 13 (depends on 3) The illumination system as claimed in claim 3, wherein the fourth light beam is a red light beam. ### Claim 14 (depends on 13) The illumination system as claimed in claim 13, wherein the third light source is a red laser light source. ### Claim 15 (depends on 1) The illumination system as claimed in claim 1, wherein the optical device comprises a first lens and a second lens disposed along the main optical axis. ### Claim 16 (depends on 1) The illumination system as claimed in claim 1, wherein the illumination system further comprises a light homogenizing device disposed at the first focal point. ### Claim 17 (depends on 16) The illumination system as claimed in claim 16, wherein the light homogenizing device is an integration rod or a light tunnel. ### Claim 18 (depends on 1) The illumination system as claimed in claim 1, wherein the first focal point and the second focal point are conjugate with each other. ### Claim 19 (depends on 18) The illumination system as claimed in claim 18, wherein an included angle defined by the first focal point and the main optical axis is equal to an included angle defined by the second focal point and the main optical axis.