# US 8,465,158 B2 · Light source device, projection apparatus, and projection method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,465,158 B2 - Document ID: US8465158B2 - Status: Granted - Kind: B2 - Application number: 12/955,024 - Filed: 2010-11-29 - Published: 2011-06-02 - Granted: 2013-06-18 - Earliest claimed: 2009-11-30 - Assignees: Casio Computer Co., Ltd. - Applicants: Hideo Suzuki; Mamoru Shibasaki - Inventors: Hideo Suzuki; Mamoru Shibasaki - Web page: https://patentgrep.com/patent/US8465158B2 ## CPC - G03B 33/08: Sequential recording or projection (G03B33/02, G03B33/04, G03B33/06 take precedence) - G03B 21/2013: {Plural light sources} - G03B 21/2033: {LED or laser light sources} - G03B 21/2053: {Intensity control of illuminating light (controlled by video signal processing H04N5/74 or H04N9/31)} - G09G 3/001: {using specific devices not provided for in groups G09G3/02 - G09G3/36, e.g. using an intermediate record carrier such as a film slide; Projection systems; Display of non-alphanumerical information, solely or in combination with alphanumerical information, e.g. digital display on projected diapositive as background (slide projectors per se G03B23/00 = 42 HP)} - H05B 45/20: Controlling the colour of the light - G09G 2310/0235: Field-sequential colour display - G09G 2310/027: Details of drivers for data electrodes, the drivers handling digital grey scale data, e.g. use of D/A converters - G09G 2320/041: Temperature compensation - G09G 2320/0633: by amplitude modulation of the brightness of the illumination source - G09G 2320/0646: Modulation of illumination source brightness and image signal correlated to each other - 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) - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A plurality of semiconductor light-emitting elements separately emits light of each of a plurality of colors. A reference signal output section outputs a reference signal for each of the plurality of colors. A selection section selects a reference signal for each of the plurality of colors output from the reference signal output section in accordance with a light-emission timing of each of the plurality of semiconductor light-emitting elements. An operation control section, provided for each of the plurality of semiconductor light-emitting elements, holds an operation value fitted to a light-emitting characteristic of a corresponding semiconductor light-emitting element and converts the reference signal selected by the selection section by an operation. A drive section drives corresponding one of the plurality of semiconductor light-emitting elements on the basis of a signal which has converted by the operation control section. ## Claims ### Claim 1 A light source device comprising: a plurality of semiconductor light-emitting elements configured to separately emit light of predetermined wavelength regions; a reference signal output unit configured to output a reference signal common to the plurality of semiconductor light-emitting elements; a control unit configured to convert the reference signal output by the reference signal output unit into dimming control signals to be fitted to light-emitting characteristics of the plurality of semiconductor light-emitting elements; and a drive unit configured to drive the plurality of semiconductor light-emitting elements on the basis of the dimming control signals converted by the control unit. ### Claim 2 (depends on 1) The light source device according to claim 1, wherein the control unit is provided for each of the plurality of semiconductor light-emitting elements. ### Claim 3 (depends on 1) The light source device according to claim 1, wherein the reference signal is a signal representing a maximum current value or a maximum voltage value of each of the plurality of semiconductor light-emitting elements to be driven. ### Claim 4 (depends on 1) The light source device according to claim 1, wherein the control unit is configured to hold operation values fitted to the light-emitting characteristics of the plurality of semiconductor light-emitting elements, and to convert the reference signal to the dimming control signals on the basis of the operation values. ### Claim 5 (depends on 4) The light source device according to claim 4, wherein the operation values are information representing percentages relative to the reference signal. ### Claim 6 (depends on 1) The light source device according to claim 1, wherein the control unit includes a digital-to-analog converter, and is configured to input the operation values to the digital-to-analog converter and input the reference signal as an input voltage of the digital-to-analog converter, thereby converting the reference signal into the dimming control signals as output values of the digital-to-analog converter. ### Claim 7 (depends on 1) The light source device according to claim 1, further comprising a fluorescent substance having fields configured to emit fluorescence of a plurality of colors by irradiation of light of a predetermined wavelength region, wherein the light source device is configured to time-divisionally generate the plurality of colors by using the plurality of semiconductor light-emitting elements and the fluorescent substance. ### Claim 8 (depends on 1) The light source device according to claim 1, wherein the reference signal output unit is configured to output the reference signal for each of the plurality of colors. ### Claim 9 (depends on 8) The light source device according to claim 8, further comprising a selection unit configured to select a reference signal for each of the plurality of colors output by the reference signal output unit in accordance with a light-emission timing of each of the plurality of colors time-divisionally generated. ### Claim 10 (depends on 1) The light source device according to claim 1, further comprising a projection mode holding unit configured to hold a plurality of projection modes, wherein the reference signal output unit has a plurality of reference signal sets to correspond to the plurality of projection modes. ### Claim 11 (depends on 1) The light source device according to claim 1, wherein the control unit is configured to convert the reference signal such that brightness of the plurality of semiconductor light-emitting elements caused to emit light by the drive unit becomes uniform. ### Claim 12 (depends on 1) The light source device according to claim 1, further comprising a temperature detection unit, provided for each of the plurality of semiconductor light-emitting elements, and configured to detect a temperature of each semiconductor light-emitting element, wherein the control unit is configured to convert the reference signal output by the reference signal output unit into each dimming control signal in accordance with a temperature of each of the semiconductor light-emitting elements detected by the temperature detection unit. ### Claim 13 A projection apparatus comprising: a light source device comprising: a plurality of semiconductor light-emitting elements configured to separately emit light of predetermined wavelength regions, a reference signal output unit configured to output a reference signal common to the plurality of semiconductor light-emitting elements, a control unit configured to convert the reference signal into dimming control signals to be fitted to light-emitting characteristics of the plurality of semiconductor light-emitting elements, and a drive unit configured to drive the plurality of semiconductor light-emitting elements on the basis of the dimming control signals converted by the control unit; an input unit configured to input an image signal; and a projection unit configured to form and project a light figure of a color corresponding to the image signal input by the input unit by using light-source light from the light source device. ### Claim 14 A projection method for use in a projection apparatus including a plurality of semiconductor light-emitting elements configured to separately emit light of predetermined wavelength regions, an input unit configured to input an image signal, and a projection unit configured to form and project a light figure of a color corresponding to the image signal input by the input unit by using light-source light from the plurality of semiconductor light-emitting elements, the method comprising: outputting a reference signal common to the plurality of semiconductor light-emitting elements; converting the output reference signal into dimming control signals to be fitted to light-emitting characteristics of the plurality of semiconductor light-emitting elements; and driving the plurality of semiconductor light-emitting elements on the basis of the dimming control signals.