# US 10,481,473 B2 · Image projection apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,473 B2 - Document ID: US10481473B2 - Status: Granted - Kind: B2 - Application number: 16/059,507 - Filed: 2018-08-09 - Published: 2019-02-14 - Granted: 2019-11-19 - Earliest claimed: 2017-08-10 - Assignees: Canon Kabushiki Kaisha - Applicants: Canon Kabushiki Kaisha - Inventors: Yuuki Maeda - Web page: https://patentgrep.com/patent/US10481473B2 ## CPC - G03B 21/2033: {LED or laser light sources} - G02B 13/16: for use in conjunction with image converters or intensifiers {, or for use with projectors, e.g. objectives for projection TV} - G03B 21/005: {Projectors using an electronic spatial light modulator but not peculiar thereto} - G03B 21/006: {using LCD's} - G03B 21/008: {using micromirror devices} - G03B 21/2073: {Polarisers in the lamp house (peculiar to electronic spatial light modulators H04N9/3197)} - G03B 21/28: Reflectors in projection beam {(in illumination beam G03B21/2066)} - H04N 9/3126: {for spatial light modulators in series} - H04N 9/3167: {for polarizing the light beam (polarizing optical systems per se G02B27/28)} - G02B 27/1026: {for use with reflective spatial light modulators} - G02B 27/141: {using dichroic mirrors} - G02B 27/149: {using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes} - G02B 27/283: {used for beam splitting or combining} - G03B 21/2066: {Reflectors in illumination beam (in projection beam G03B21/28)} - 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 - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image projection apparatus includes a first light modulation element configured to modulate first light from a light source and to generate second light, a second light modulation element configured to modulate second light, an imaging optical system configured to image the second light on the second light modulation element and disposed on an optical path from the first light modulation element to the second light modulation element. The image projection apparatus is configured to project an image formed by light from the second light modulation element onto a projection surface and satisfies a predetermined condition. ## Claims ### Claim 1 An image projection apparatus comprising: a first light modulation element configured to modulate first light from a light source and to generate second light, the first light modulation element having a first number of pixels that modulate the first light; a second light modulation element configured to modulate the second light, the second light modulation element having a second number of pixels that modulate the second light, the second number of pixels of the second light modulation element that modulate the second light being greater in number than the first number of pixels of the first light modulation element that modulate the first light; an imaging optical system configured to image the second light on the second light modulation element and disposed on an optical path from the first light modulation element to the second light modulation element, wherein the image projection apparatus is configured to project an image formed by light from the second light modulation element onto a projection surface, and wherein the imaging optical system satisfies β≤0.95 where β is an imaging magnification of the imaging optical system. ### Claim 2 (depends on 1) The image projection apparatus according to claim 1, wherein an area of the first light modulation element over which the first light is incident is larger than an area of the second light modulation element over which the second light is incident. ### Claim 3 (depends on 1) The image projection apparatus according to claim 1, wherein an effective pixel area in the first light modulation element which modulates the first light into an irradiated light to the second light modulation element is smaller than a modulable pixel area configured to modulate light in the first light modulation element. ### Claim 4 (depends on 1) The image projection apparatus according to claim 1, wherein an effective pixel area in the first modulation element has a shape similar to an effective pixel area that modulates the second light in the second light modulation element. ### Claim 5 (depends on 1) The image projection apparatus according to claim 1, wherein the imaging optical system is a telecentric optical system on both sides of the first light modulation element and the second light modulation element. ### Claim 6 (depends on 1) The image projection apparatus according to claim 1, further comprising: a color separation element configured to receive and separate the second light into a plurality of different color light fluxes; and a polarization plate provided between the first light modulation element and the second light modulation element. ### Claim 7 (depends on 6) The image projection apparatus according to claim 6, wherein the polarization plate is an absorption type polarization plate. ### Claim 8 (depends on 1) The image projection apparatus according to claim 1, further comprising a polarization conversion element configured to receive and convert the first light into polarized light, and wherein the first light modulation element is a liquid crystal panel. ### Claim 9 An image projection apparatus comprising: a first light modulation element configured to modulate first light from a light source and to generate second light, the first light modulation element having a first number of pixels that modulate the first light; a second light modulation element configured to modulate the second light, the second light modulation element having a second number of pixels that modulate the second light, the second number of pixels of the second light modulation element that modulate the second light being greater in number than the first number of pixels of the first light modulation element that modulate the first light; an imaging optical system configured to image the second light on the second light modulation element and disposed on an optical path from the first light modulation element to the second light modulation element, wherein the image projection apparatus is configured to project an image formed by light from the second light modulation element onto a projection surface. ### Claim 10 (depends on 9) The image projection apparatus according to claim 9, wherein an area of the first light modulation element over which the first light is incident is larger than an area of the second light modulation element over which the second light is incident. ### Claim 11 (depends on 9) The image projection apparatus according to claim 9, wherein an effective pixel area in the first light modulation element which actually modulates the first light into an irradiated light to the second light modulation element is smaller than a modulable pixel area configured to modulate light in the first light modulation element. ### Claim 12 (depends on 9) The image projection apparatus according to claim 9, wherein an effective pixel area in the first modulation element has a shape similar to an effective pixel area that modulates the second light in the second light modulation element. ### Claim 13 (depends on 9) The image projection apparatus according to claim 9, wherein the imaging optical system is a telecentric optical system on both sides of the first light modulation element and the second light modulation element. ### Claim 14 (depends on 9) The image projection apparatus according to claim 9, further comprising: a color separation element configured to receive and separate the second light into a plurality of different color light fluxes; and a polarization plate provided between the first light modulation element and the second light modulation element.