# US 8,786,757 B2 · Wideband ambient light rejection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,757 B2 - Document ID: US8786757B2 - Status: Granted - Kind: B2 - Application number: 13/031,627 - Filed: 2011-02-22 - Published: 2011-08-25 - Granted: 2014-07-22 - Earliest claimed: 2010-02-23 - Assignees: Primesense Ltd. - Applicants: Alexander Shpunt; Niv Gilboa; Haim Bezdin - Inventors: Alexander Shpunt; Niv Gilboa; Haim Bezdin - Web page: https://patentgrep.com/patent/US8786757B2 ## CPC - H04N 23/75: by influencing optical camera components - G02B 27/0944: {Diffractive optical elements, e.g. gratings, holograms (gratings per se G02B5/18; holograms used as optical elements per se G02B5/32)} - G02B 27/0955: {Lenses (lenses per se G02B3/00)} - G02B 27/1066: {for enhancing image performance, like resolution, pixel numbers, dual magnifications or dynamic range, by tiling, slicing or overlapping fields of view} - G02B 27/12: operating by refraction only - G02B 27/4205: {having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant} - H04N 9/646: {for image enhancement, e.g. vertical detail restoration, cross-colour elimination, contour correction, chrominance trapping filters} - H04N 13/106: Processing image signals (for multi-view video sequence encoding H04N19/597) - H04N 13/257: Colour aspects - H04N 13/271: wherein the generated image signals comprise depth maps or disparity maps - H04N 23/11: for generating image signals from visible and infrared light wavelengths - H04N 23/45: for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract Optical apparatus includes an image sensor and objective optics, which are configured to collect and focus optical radiation over a range of wavelengths along a common optical axis toward a plane of the image sensor. A dispersive element is positioned to spread the optical radiation collected by the objective optics so that different wavelengths in the range are focused along different, respective optical axes toward the plane. ## Claims ### Claim 1 Optical apparatus, comprising: an image sensor; objective optics, which are configured to collect and focus optical radiation over a range of wavelengths along a common optical axis toward a plane of the image sensor; a dispersive element, which is positioned to spread the optical radiation collected by the objective optics so that different wavelengths in the range are focused along different, respective optical axes toward the plane, wherein the dispersive element comprises a diffractive element, which comprises a grating configured to direct a selected diffraction order onto the image sensor; and an interference filter positioned between the grating and the image sensor so as to block stray diffraction orders, other than the selected diffraction order, from reaching the image sensor. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the dispersive element is configured to cause the image sensor to capture a sharp image of the optical radiation emitted from an object at a target wavelength within the range, while spreading broadband background radiation within the range across the plane. ### Claim 3 (depends on 2) The apparatus according to claim 2, and comprising a projection assembly, which is configured to project the optical radiation at the target wavelength onto the object, so that the emitted optical radiation collected by the objective comprises the projected optical radiation that is reflected from the object. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein the projected optical radiation comprises a predetermined radiation pattern, and wherein the sharp image captured by the image sensor comprises an image of the pattern projected onto the object. ### Claim 5 (depends on 2) The apparatus according to claim 2, and comprising a processor, which is configured to process the sharp image captured by the image sensor while rejecting interference caused by the background radiation. ### Claim 6 (depends on 5) The apparatus according to claim 5, wherein the processor is configured to construct a 3D map of the object by processing the sharp image. ### Claim 7 (depends on 1) The apparatus according to claim 1, wherein the dispersive element is configured so that the optical radiation is focused with a chromatic aberration in excess of one micrometer per nanometer of wavelength at the plane of the image sensor. ### Claim 8 Optical apparatus, comprising: an image sensor; objective optics, which are configured to collect and focus optical radiation over a range of wavelengths along a common optical axis toward a plane of the image sensor; a dispersive element, which is positioned to spread the optical radiation collected by the objective optics so that different wavelengths in the range are focused along different, respective optical axes toward the plane, wherein the dispersive element has a first tilt relative to the optical axis, and wherein the apparatus comprises a wedged lens, which is configured to focus the optical radiation with a second tilt, opposite to the first tilt. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the wedged lens comprises a section of an axially-symmetrical lens. ### Claim 10 (depends on 8) The apparatus according to claim 8, wherein the dispersive element is configured to cause the image sensor to capture a sharp image of the optical radiation emitted from an object at a target wavelength within the range, while spreading broadband background radiation within the range across the plane. ### Claim 11 (depends on 10) The apparatus according to claim 10, and comprising a projection assembly, which is configured to project the optical radiation at the target wavelength onto the object, so that the emitted optical radiation collected by the objective comprises the projected optical radiation that is reflected from the object. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the projected optical radiation comprises a predetermined radiation pattern, and wherein the sharp image captured by the image sensor comprises an image of the pattern projected onto the object. ### Claim 13 (depends on 10) The apparatus according to claim 10, and comprising a processor, which is configured to process the sharp image captured by the image sensor while rejecting interference caused by the background radiation. ### Claim 14 (depends on 13) The apparatus according to claim 13, wherein the processor is configured to construct a 3 D map of the object by processing the sharp image. ### Claim 15 A method for imaging, comprising: collecting and focusing optical radiation over a range of wavelengths along a common optical axis toward a plane of an image sensor; positioning a dispersive element to spread the collected optical radiation so that different wavelengths in the range are focused along different, respective optical axes toward the plane, wherein the dispersive element comprises a diffractive element, which comprises a grating, and wherein positioning the dispersive element comprises configuring the grating to direct a selected diffraction order onto the image sensor; and positioning an interference filter between the grating and the image sensor so as to block stray diffraction orders, other than the selected diffraction order, from reaching the image sensor. ### Claim 16 (depends on 15) The method according to claim 15, wherein positioning the dispersive element causes the image sensor to capture a sharp image of the optical radiation emitted from an object at a target wavelength within the range, while spreading broadband background radiation within the range across the plane. ### Claim 17 (depends on 16) The method according to claim 16, and comprising projecting the optical radiation at the target wavelength onto the object, so that the optical radiation emitted from the object comprises the projected optical radiation that is reflected from the object. ### Claim 18 (depends on 17) The method according to claim 17, wherein the projected optical radiation comprises a predetermined radiation pattern, and wherein the sharp image captured by the image sensor comprises an image of the pattern projected onto the object. ### Claim 19 (depends on 16) The method according to claim 16, and comprising processing the sharp image captured by the image sensor while rejecting interference caused by the background radiation. ### Claim 20 (depends on 19) The method according to claim 19, wherein processing the sharp image comprises constructing a 3D map of the object by processing the sharp image. ### Claim 21 (depends on 15) The method according to claim 15, wherein the dispersive element is configured so that the optical radiation is focused with a chromatic aberration in excess of one micrometer per nanometer of wavelength at the plane of the image sensor. ### Claim 22 A method for imaging, comprising: collecting and focusing optical radiation over a range of wavelengths along a common optical axis toward a plane of an image sensor; and positioning a dispersive element to spread the collected optical radiation so that different wavelengths in the range are focused along different, respective optical axes toward the plane, wherein positioning the dispersive element comprises applying to the dispersive element a first tilt relative to the optical axis, and wherein collecting and focusing the optical radiation comprises positioning a wedged lens to focus the optical radiation with a second tilt, opposite to the first tilt. ### Claim 23 (depends on 22) The method according to claim 22, wherein the wedged lens comprises a section of an axially-symmetrical lens. ### Claim 24 (depends on 22) The method according to claim 22, wherein positioning the dispersive element causes the image sensor to capture a sharp image of the optical radiation emitted from an object at a target wavelength within the range, while spreading broadband background radiation within the range across the plane. ### Claim 25 (depends on 24) The method according to claim 24, and comprising projecting the optical radiation at the target wavelength onto the object, so that the optical radiation emitted from the object comprises the projected optical radiation that is reflected from the object. ### Claim 26 (depends on 25) The method according to claim 25, wherein the projected optical radiation comprises a predetermined radiation pattern, and wherein the sharp image captured by the image sensor comprises an image of the pattern projected onto the object. ### Claim 27 (depends on 24) The method according to claim 24, and comprising processing the sharp image captured by the image sensor while rejecting interference caused by the background radiation. ### Claim 28 (depends on 27) The method according to claim 27 wherein processing the sharp image comprises constructing a 3D map of the object by processing the sharp image. ### Claim 29 A method for imaging, comprising: projecting optical radiation at a target wavelength onto an object; collecting and focusing the optical radiation reflected from the object, along with background radiation over a range of wavelengths, toward a plane of an image sensor; positioning a dispersive element to direct the collected optical radiation so as to form a sharp image of the optical radiation at the target wavelength in the plane of the image sensor, while spreading the background radiation across the plane, wherein positioning the dispersive element comprises shifting a position of the dispersive element relative to the plane so as to select the target wavelength that is to be imaged sharply in the plane; and processing the sharp image captured by the image sensor while rejecting interference caused by the background radiation. ### Claim 30 (depends on 29) The method according to claim 29, wherein the projected optical radiation comprises a predetermined radiation pattern, and wherein the sharp image captured by the image sensor comprises an image of the pattern projected onto the object, and wherein processing the image comprises constructing a 3D map of the object by processing the sharp image. ### Claim 31 (depends on 29) The method according to claim 29, wherein positioning the dispersive element comprises spreading the optical radiation collected by the optics so that different wavelengths in the range are focused along different, respective optical axes toward the plane of the image sensor. ### Claim 32 (depends on 29) The method according to claim 29, wherein the dispersive element is configured so that the optics have a chromatic aberration in excess of one micrometer per nanometer of wavelength at the plane of the image sensor.