# US 6,534,772 B1 · High resolution high output microchannel based radiation sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,534,772 B1 - Document ID: US6534772B1 - Status: Granted - Kind: B1 - Application number: 09/688,662 - Filed: 2000-10-16 - Granted: 2003-03-18 - Earliest claimed: 1997-11-28 - Assignees: Nanocrystal Imaging Corporation - Inventors: Vishal Chhabra; Rameshwar Nath Bhargava; Dennis Gallagher; Samuel P. Herko; Bharati S. Kulkarni; Nikhil R. Taskar; Aleksey Yekimov - Web page: https://patentgrep.com/patent/US6534772B1 ## CPC - G21K 4/00: Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens (photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50) - G01T 1/20: with scintillation detectors - G01T 1/2921: {Static instruments for imaging the distribution of radioactivity in one or two dimensions; Radio-isotope cameras (using scintigraphy G01T1/1641)} - G21K 2004/06: {with a phosphor layer} - G21K 2004/12: {with a support} - H01J 2231/50036: X-rays - H01J 2231/5016: Michrochannel plates [MCP] - Y10S 977/89: Deposition of materials, e.g. coating, cvd, or ald - G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES - G01T: MEASUREMENT OF NUCLEAR OR X-RADIATION (radiation analysis of materials, mass spectrometry G01N23/00; tubes for determining the presence, intensity, density or energy of radiation or particles H01J47/00) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A microchannel phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced microchannels having diameters of the order of 40 microns or less. Deposited within each of the microchannels is a multiplicity of phosphors which emit light when acted upon by radiation. The dimensions of the microchannel and the phosphors and the relationship between the microchannels and the phosphors is optimized so that the light output compares favorably with lower resolution non microchannel based scintillation screens. A photomultiplier can be integrated with the X-ray detector so as to provide an enhanced output for use with low level X-ray of for cine or fluoroscopy applications. ## Claims ### Claim 1 A high resolution high output phosphor screen for the conversion of radiation impinging thereon to visible light, comprising: a) a substrate having a planar surface; b) a multiplicity of microchannels extending into the surface of the substrate, each of said microchannels having a diameter of less than 40 microns, c) a multiplicity of phosphors disposed in each of said microchannels, said phosphors emitting visible light when exposed to radiation and having diameters of from about 25 to 80% of the diameter of the microchannels, and d) a reflective coating disposed along the walls of the microchannels. ### Claim 2 (depends on 1) The phosphor screen as claimed in claim 1 wherein the phosphors have diameters of from about 40 to 75% of the diameter of the microchannels. ### Claim 3 (depends on 1) The phosphor screen as claimed in claim 1 wherein said reflective coating has a reflectivity of at least 85%. ### Claim 4 (depends on 1) The phosphor screen as claimed in claim 1 wherein said reflective coating has a reflectivity of at least 90%. ### Claim 5 (depends on 1) The phosphor screen as claimed in claim 1, wherein the microchannels have a center to center spacing of 1-12 microns. ### Claim 6 (depends on 1) The phosphor screen as claimed in claim 1, wherein the reflective coating has a thickness of less than about 50 nanometers. ### Claim 7 (depends on 1) The phosphor screen as claimed in claim 1, wherein the plate has a thickness of from about 50 microns to about 2000 microns. ### Claim 8 (depends on 1) The phosphor screen as claimed in claim 1 wherein the quantity of phosphors disposed in the microchannels is sufficient to absorb no more then 90% of the radiation impinging on the phosphor screen. ### Claim 9 (depends on 1) The phosphor screen as claimed in claim 1 further including refractive matching material disposed in the microchannels together with the phosphors. ### Claim 10 (depends on 1) The phosphor screen as claimed in claim 1 wherein the radiation that is to be converted comprises X-rays. ### Claim 11 A high resolution high output phosphor screen for the conversion of radiation impinging thereon to visible light, comprising: a) a substrate having a planar surface; b) a multiplicity of microchannels extending into the surface of the substrate, said microchannels having a diameter of less than 40 microns, c) a multiplicity of phosphors disposed in each of said microchannels, and d) a reflective coating disposed along the walls of the microchannels, said reflective coating having a reflectivity of at least 85%. ### Claim 12 (depends on 11) The phosphor screen as claimed in claim 11 wherein the phosphors have diameters of from 25 to 80% of the diameter of the microchannels. ### Claim 13 (depends on 11) The phosphor screen as claimed in claim 11 wherein the phosphors have diameters of from 40 to 75% of the diameter of the microchannels. ### Claim 14 (depends on 11) The phosphor screen as claimed in claim 11 wherein said reflective coating has a reflectivity of at least 90%. ### Claim 15 (depends on 11) The phosphor screen as claimed in claim 11, wherein the microchannels have a center to center spacing of 1-12 microns. ### Claim 16 (depends on 11) The phosphor screen as claimed in claim 11, wherein the reflective coating has a thickness of less than about 50 microns. ### Claim 17 (depends on 11) The phosphor screen as claimed in claim 11, wherein the plate has a thickness of from about 50 microns to about 2000 microns. ### Claim 18 (depends on 11) The phosphor screen as claimed in claim 11 wherein the quantity of phosphors disposed in the microchannels is sufficient to absorb no more than about 90% of the radiation impinging on the phosphor screen. ### Claim 19 (depends on 11) The phosphor screen as claimed in claim 11 further including refractive matching material disposed in the microchannels together with the phosphors. ### Claim 20 (depends on 11) The phosphor screen as claimed in claim 11 wherein the radiation that is to be converted comprises X-rays. ### Claim 21 A compact high resolution digital X-ray imaging system comprising: a) a microchannel phosphor screen formed from a substrate having a planar surface; b) a multiplicity of microchannels extending into the surface of the substrate, said microchannels having a diameter of less than 40 microns, c) a quantity of phosphors disposed in each of said microchannels, said phosphors emitting visible light when exposed to radiation and having diameters of from 25 to 80% of the diameter of the microchannels, and a reflective coating disposed along the walls of the microchannels, said reflective coating having a reflectivity of at least 85%; c) an electronic image sensor disposed so as to intercept the visible light emitted by the phosphors for creating an image of the light; and; d) means for storing and displaying the image formed by the electronic image sensor. ### Claim 22 (depends on 21) The compact high resolution digital X-ray imaging system as claimed in claim 21 further including a photomultiplier having a faceplate and a rearplate disposed between the phosphor screen and the electronic image sensor so as to intercept the visible light emitted by the phosphors to multiply same. ### Claim 23 (depends on 22) The digital X-ray system as claimed in claim 22 wherein the microchannel phosphor screen is mounted to the faceplate of the photomultiplier. ### Claim 24 (depends on 22) The digital X-ray system as claimed in claim 22 wherein the electronic image sensor is mounted to the rearplate of the photomultiplier. ### Claim 25 (depends on 21) The digital X-ray system as claimed in claim 21 further including a reflective coating disposed along the walls of said microchannels of said microchannel phosphor screen. ### Claim 26 (depends on 21) The digital X-ray system as claimed in claim 21 wherein the means for storing and displaying the image formed by the electronic image sensor comprise a computer. ### Claim 27 (depends on 21) The digital X-ray system as claimed in claim 21 wherein the photomultiplier comprises a microchannel based image intensifier. ### Claim 28 (depends on 21) The digital X-ray system as claimed in claim 21 further including means to displace the microchannel phosphor screen through space through a number of different positions while storing images taken at each such position. ### Claim 29 (depends on 21) The digital X-ray system as claimed in claim 21 wherein the phosphors have diameters of from 40 to 75% of the diameter of the microchannels. ### Claim 30 (depends on 21) The digital X-ray system as claimed in claim 21 wherein said reflective coating has a reflectivity of at least 90%. ### Claim 31 A microchannel plate, comprising: a) a planar substrate; b) a multiplicity of microchannels extending into the surface of the substrate, said microchannels having a diameter of less than 40 microns, c) a reflective coating disposed along the walls of the microchannels said reflective coating having a reflectivity of at least 85%. ### Claim 32 (depends on 31) The microchannel plate as claimed in claim 31, wherein the reflactive coating has a thickness of less than about 50 microns. ### Claim 33 (depends on 31) The microchannel plate as claimed in claim 31, wherein the plate has a thickness of from about 50 microns to about 2000 microns. ### Claim 34 (depends on 31) The microchannel plate as claimed in claim 31, wherein the surface of the microchannels has no irregularities of more than 0.05 microns. ### Claim 35 (depends on 31) The microchannel plate as claimed in claim 31, wherein the microchannels are spaced apart a distance of from 1 to 12 microns. ### Claim 36 (depends on 31) The microchannel plate as claimed in claim 31, wherein the coating has a reflectivity of greater than 90%. ### Claim 37 (depends on 31) The microchannel plate as claimed in claim 31, further including a multiplicity of phosphors disposed in each of said microchannels, said phosphors emitting visible light when exposed to radiation and having diameters of from 25 to 80% of the diameter of the microchannels. ### Claim 38 (depends on 37) The microchannel plate as claimed in claim 37, wherein the phosphors have diameters of from 40 to 75% of the diameter of the microchannels. ### Claim 39 (depends on 37) The microchannel plate as claimed in claim 37, wherein the average size of irregularities in the walls of the microchannels is less than about one tenth of the wavelength of the light emitted by the phosphors. ### Claim 40 (depends on 1) The microchannel plate as claimed in claim 1, wherein the average size of irregularities in the walls of the microchannels is less than about one tenth of the wavelength of the light emitted by the phosphors. ### Claim 41 (depends on 11) The phosphor screen as claimed in claim 11, wherein the average size of irregularities in the walls of the microchannels is less than about one tenth of the wavelength of the light emitted by the phosphors. ### Claim 42 (depends on 21) The digital X-ray system as claimed in claim 21, wherein the average size of irregularities in the walls of the microchannels is less than about one tenth of the wavelength of the light emitted by the phosphors. ### Claim 43 A scintillation plate, comprising: a) a planar substrate; b) a multiplicity of microchannels extending into the surface of the substrate, said microchannels being formed by the removal of glass fibers extending perpendicular to the surface of the planar substrate; and c) a quantity of phosphors disposed in each of said microchannels, said phosphors emitting visible light when exposed to radiation. ### Claim 44 (depends on 43) The scintillation plate as claimed in claim 43 wherein the glass fibers are removed by chemically dissolving the glass fibers. ### Claim 45 (depends on 43) The scintillation plate as claimed in claim 43 further including a reflective coating disposed along the walls of the microchannels said reflective coating having a reflectivity of at least 85%. ### Claim 46 (depends on 43) The scintillation plate as claimed in claim 43 wherein the microchannels have a diameter of less than about 40 microns. ### Claim 47 (depends on 43) The scintillation plate as claimed in claim 43, wherein the average size of irregularities in the walls of the microchannels is less than about one tenth of the wavelength of the light emitted by the phosphors. ### Claim 48 (depends on 43) The scintillation plate as claimed in claim 43, wherein the phosphors have diameters of from 25 to 80% of the diameter of the microchannels. ### Claim 49 (depends on 43) The scintillation plate as claimed in claim 43 wherein the quantity of phosphors disposed in the microchannels is sufficient to absorb no more than about 90% of the radiation impinging on the phosphor screen. ### Claim 50 (depends on 43) The scintillation plate as claimed in claim 43, wherein the microchannels have a center to center spacing of 1-12 microns.