# US 9,039,215 B2 · Light source device and projection type display device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,215 B2 - Document ID: US9039215B2 - Status: Granted - Kind: B2 - Application number: 13/824,783 - Filed: 2011-05-31 - Published: 2013-07-11 - Granted: 2015-05-26 - Earliest claimed: 2010-10-21 - Assignees: NEC Corporation - Applicants: Masahiko Ohta - Inventors: Masahiko Ohta - Web page: https://patentgrep.com/patent/US9039215B2 ## CPC - F21V 13/12: Combinations of only three kinds of elements - F21V 9/00: Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters (coloured shades F21V1/00; elements characterised by cooling arrangements F21V29/502) - 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 9/3105: {for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators (simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10)} - H04N 9/3161: {using laser light sources (using laser beams scanning the display screen H04N9/3129)} - H01S 5/0087: {for illuminating phosphorescent or fluorescent materials, e.g. using optical arrangements specifically adapted for guiding or shaping laser beams illuminating these materials} - H01S 5/4056: {emitting light in more than one direction} - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - 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 - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract A light source device includes a light source unit concluding LD element (1) for emitting a laser beam polarized in a particular direction and lens (2) for condensing the laser beam emitted from LD element (1) and phosphor layer (3) excited by the laser beam condensed by lens (2) of the light source unit to discharge incoherent light. The incident angle of the laser beam to phosphor layer (3) is larger than 0° and smaller than 90°, and the laser beam enters phosphor layer (3) as P-polarized light. ## Claims ### Claim 1 A light source device comprising: a light source unit including a laser diode emitting a laser beam polarized in a particular direction and a light collection optical system condensing the laser beam emitted from the laser diode; and a phosphor layer excited by the laser beam condensed by the light collection optical system of the light source unit, the phosphor layer emitting incoherent light, wherein the laser diode and the phosphor layer are arranged such that an incident angle, which is an angle formed between an optical axis of the laser beam and a normal line of the phosphor layer, is larger than 0° and smaller than 90° and such that the laser beam enters the phosphor layer as P-polarized light. ### Claim 2 A light source device comprising: a light source unit including a laser diode emitting a laser beam polarized in a particular direction, a polarization conversion element rotating a polarizing direction of the laser beam emitted from the laser diode, and a light collection optical system condensing the laser beam rotated in the polarizing direction by the polarization conversion element; and a phosphor layer excited by the laser beam condensed by the light collection optical system of the light source unit, the phosphor layer emitting incoherent light, wherein: an incident angle of the laser beam to the phosphor layer is larger than 0° and smaller than 90°; and the laser beam enters the phosphor layer as P-polarized light. ### Claim 3 (depends on 1) The light source device according to claim 1, wherein a following relationship is established, in which θ denotes the incident angle, n1 denotes a refractive index of a medium around the phosphor layer, and n2 denotes a refractive index of the phosphor layer: θ=Arctan(n2/n1). ### Claim 4 (depends on 1) The light source device according to claim 1, wherein a following relationship is established, in which θ denotes the incident angle, Dx and Dy respectively denote a long-axis direction and a short-axis direction in a laser beam section immediately after emission from the laser diode, and dx and dy respectively denote diameters of the Dx direction and the Dy direction in the laser beam section: θ=Arccos(dx/dy). ### Claim 5 (depends on 1) The light source device according to claim 1, wherein a following relationship is established, in which θ denotes the incident angle, Dx and Dy respectively denote a long-axis direction and a short-axis direction in a laser beam section immediately after emission from the laser diode, and dx and dy respectively denote diameters of the Dx direction and the Dy direction in the laser beam section: θ=Arccos(dx/dy). ### Claim 6 (depends on 1) The light source device according to claim 1, further comprising a reflection plate facing a surface of a reflection side opposite a surface of the phosphor layer into which the laser beam enters. ### Claim 7 (depends on 1) The light source device according to claim 1, further comprising a lens condensing a light flux emitted from the phosphor layer. ### Claim 8 (depends on 1) The light source device according to claim 1, further comprising a reflector condensing a light flux emitted from the phosphor layer. ### Claim 9 (depends on 1) The light source device according to claim 1, further comprising a plurality of light source units for one phosphor layer. ### Claim 10 (depends on 1) A projection type display device comprising: the light source device according to claim 1. ### Claim 11 (depends on 1) The light source device according to claim 1, further comprising a polarization conversion element rotating a polarizing direction of the laser beam emitted from the laser diode, wherein the light collection optical system condenses the laser beam rotated in the polarizing direction by the polarization conversion element. ### Claim 12 (depends on 1) The light source device according to claim 1, wherein a relationship “dy>dx” is established at a position of the phosphor layer, when Dx and Dy respectively denote a long-axis direction and a short-axis direction in a laser beam section immediately after emission from the laser diode, and dx and dy respectively denote diameters of the Dx direction and the Dy direction in the laser beam section. ### Claim 13 (depends on 2) The light source device according to claim 2, wherein the polarization conversion element is a half-wave plate. ### Claim 14 (depends on 2) The light source device according to claim 2, wherein a relationship “dx>dy” is established at a position of the phosphor layer, when Dx and Dy respectively denote a long-axis direction and a short-axis direction in a laser beam section immediately after emission from the laser diode, and dx and dy respectively denote diameters of the Dx direction and the Dy direction in the laser beam section.