# US 4,397,559 A · Apparatus for processing electromagnetic radiation and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,397,559 A - Document ID: US4397559A - Status: Granted - Kind: A - Application number: 06/236,023 - Filed: 1981-02-19 - Granted: 1983-08-09 - Earliest claimed: 1981-02-19 - Assignees: University of Pittsburgh - Inventors: George D. Gatewood - Web page: https://patentgrep.com/patent/US4397559A ## CPC - G01D 5/36: Forming the light into pulses - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract Measuring apparatus including a ruled member having alternate transparent and opaque zones. An optical coupler connecting the ruled member with electromagnetic radiation-conversion apparatus. The conversion apparatus may include a photomultiplier and a discriminator. Radiation impinging on the ruled member will, in part, be converted to electrical pulses which correspond to the intensity of the radiation. A method of processing electromagnetic radiation includes providing a member having alternating dark and light zones, establishing movement of the member through the beam of electromagnetic radiation with the dark zones interrupting passage of radiation through the rule, providing an optical coupler to connect a portion of the radiation with a conversion station where the radiation portion is converted into an electrical pulse which is related to the intensity of the radiation received at the conversion station. The electrical pulses may be counted and the digitized signals stored or permanently recorded to produce positional information. ## Claims ### Claim 1 Electromagnetic radiation measuring apparatus comprising ruling means adapted to be positioned in a beam of said radiation and having a series of substantially transparent first zones, a series of substantially opaque second zones with at least some of said first or second zones disposed in alternating position with respect to the other said zones, optical coupling means for receiving radiation from said ruling means, photomultiplier means for receiving radiation from said optical coupling means and emitting responsive electrical pulses, discriminator means for permitting electrical pulses of predetermined amplitude corresponding to photon events to pass therethrough, and counter means for counting pulses passing through said discriminator means and emitting a count which is a function of the intensity of the radiation received by said optical coupling means. ### Claim 2 (depends on 1) The measuring apparatus of claim 1 including said optical coupling means having lens means. ### Claim 3 (depends on 1) The measuring apparatus of claim 1 including said optical coupling means including fiber optic means. ### Claim 4 (depends on 1) The measuring apparatus of claim 1 including amplifier means electrically interposed between said discriminator means and said counter means. ### Claim 5 (depends on 4) The measuring apparatus of claim 4 including said optical coupling means adapted to receive radiation passing through said transparent first zones of said ruling. ### Claim 6 (depends on 4) The measuring apparatus of claim 4 including said optical coupling means adapted to receive radiation reflected by said opaque second zones of said ruling. ### Claim 7 (depends on 1) The measuring apparatus of claim 1 including drive means for moving said ruling means in a generally linear path, whereby said radiation will be modulated by said ruling. ### Claim 8 (depends on 7) The measuring apparatus of claim 7 including said drive means having means for rotating said ruling. ### Claim 9 (depends on 8) The measuring apparatus of claim 8 including said drive means having means for moving said ruling means in two translational paths disposed generally perpendicularly with respect to each other, and the axis of rotation of said ruling means being disposed generally perpendicular with respect to said two paths. ### Claim 10 (depends on 7) The measuring apparatus of claim 7 including said drive means having means for reciprocating said ruling means within said generally linear path. ### Claim 11 (depends on 7) The measuring apparatus of claim 7 wherein said photomultiplier means includes a number of photomultiplier tubes. ### Claim 12 (depends on 11) The measuring apparatus of claim 11 wherein said counter means includes at least one pulse counter operatively associated with each said photomultiplier tube. ### Claim 13 (depends on 12) The measuring apparatus of claim 12 including said discriminator means having independent discriminator means operatively associated with each said photomultiplier tube and one said pulse counter. ### Claim 14 (depends on 13) The measuring apparatus of claim 13 including amplifier means electrically interposed between each said discriminator and its associated pulse counter. ### Claim 15 (depends on 13) The measuring apparatus of claim 13 including signal receiving means operatively associated with said pulse counters for receiving information corresponding to the pulse count therefrom. ### Claim 16 (depends on 15) The measuring apparatus of claim 15 including said signal receiving means including computer means. ### Claim 17 (depends on 16) The measuring apparatus of claim 16 including visual display means associated with said computer means. ### Claim 18 (depends on 17) The measuring apparatus of claim 17 including data storage means operatively associated with said computer means. ### Claim 19 (depends on 17) The measuring apparatus of claim 17 including said visual display means having means for making a permanent record. ### Claim 20 (depends on 18) The measuring apparatus of claim 18 including said data storage means including magnetic storage means. ### Claim 21 (depends on 1) The measuring apparatus of claim 1 wherein said ruling means includes a Ronchi ruling. ### Claim 22 (depends on 21) The measuring apparatus of claim 21 including said first zone and said second zone being generally parallel and of substantially equal width. ### Claim 23 (depends on 1) The measuring apparatus of claim 1 including said apparatus adapted to receive electromagnetic radiation in the form of light, and telescope means for providing a beam of said light. ### Claim 24 (depends on 23) The measuring apparatus of claim 23 including said ruling disposed generally in the focal plane of said telescope means. ### Claim 25 (depends on 2) The measuring apparatus of claim 2 wherein said lens means include a collimating lens. ### Claim 26 (depends on 16) The measuring apparatus of claim 16 wherein said computer means includes digital computer means. ### Claim 27 (depends on 1) The measuring apparatus of claim 1 including means for converting said electrical pulses into a plot of time versus electromagnetic radiation intensity. ### Claim 28 (depends on 23) The measuring apparatus of claim 23 including platen means having photomultiplier means positioned to receive light from a target object and at least two reference objects. ### Claim 29 (depends on 28) The measuring apparatus of claim 28 including said platen means having said photomultiplier means disposed so as to conform to a star field, whereby the position of one or more target stars with respect to two or more reference stars may be determined. ### Claim 30 A method of processing electromagnetic radiation comprising placing a ruling having alternating opaque and light zones in the path of a beam of said radiation, establishing movement of said ruling through said beam of radiation to cause said opaque zones to interrupt passage of light through said ruling, permitting a portion of said radiation to pass through said ruling, transporting a portion of the radiation impinging on said ruling through optical coupling means to at least one radiation conversion station, converting said radiation at said radiation conversion station into electrical pulses which are related to the intensity of the radiation received at said conversion station, counting the number of electrical pulses exceeding a predetermined magnitude, and storing the count of said pulses. ### Claim 31 (depends on 30) The method of claim 30 including moving said ruling in a substantially linear path. ### Claim 32 (depends on 31) The method of claim 31 including after moving said ruling in a linear path, rotating said ruling about an axis generally perpendicular to the upper surface of said ruling, and moving said ruling in a second linear path. ### Claim 33 (depends on 31) The method of claim 31 including moving said ruling sequentially in both directions on said linear path. ### Claim 34 (depends on 33) The method of claim 33 including after reciprocating said ruling in said linear path, rotating said ruling and reciprocating said ruling in a second linear path oriented generally perpendicularly with respect to the first said linear path. ### Claim 35 (depends on 32) The method of claim 32 including moving said ruling in both directions on both said linear paths by alternating between movement of said ruling in one direction on one said linear path and then rotating said ruling to the next said path. ### Claim 36 (depends on 30) The method of claim 30 including transporting the radiation passing through said ruling to said radiation conversion station. ### Claim 37 (depends on 30) The method of claim 30 including providing said electromagnetic radiation in the form of light. ### Claim 38 (depends on 37) The method of claim 37 including providing said light from an object in space. ### Claim 39 (depends on 38) The method of claim 38 including transporting said light passing through said ruling to said conversion station by fiber optic means. ### Claim 40 (depends on 38) The method of claim 38 including passing said light through telescope means before permitting said light to impinge on said ruling. ### Claim 41 (depends on 40) The method of claim 40 including obtaining said light from one or more stars. ### Claim 42 (depends on 41) The method of claim 41 including employing photomultiplier means in converting said light to said electrical pulses. ### Claim 43 (depends on 42) The method of claim 42 including employing discriminator means in converting said light to said electrical pulses. ### Claim 44 (depends on 43) The method of claim 43 including delivering electrical pulses corresponding to the number of light photons impinging on said photomultiplier means to a pulse counter which counts the number of said electrical pulses. ### Claim 45 (depends on 44) The method of claim 44 including periodically transferring said count on said pulse counter to storage means. ### Claim 46 (depends on 44) The method of claim 44 including simultaneously passing light from a number of sources through said ruling, and employing a number of photomultiplier means, discriminator means and pulse counter means to receive separate segments of the light passing through said ruling. ### Claim 47 (depends on 46) The method of claim 46 including delivering a count of said electrical pulses from said pulse counters to electrical signal processing means. ### Claim 48 (depends on 47) The method of claim 47 including making a permanent record of said electrical pulse count. ### Claim 49 (depends on 47) The method of claim 47 creating a plot of time versus electromagnetic radiation intensity based on said count. ### Claim 50 (depends on 47) The method of claim 47 including converting the count received from the pulse counter to a representation of the changes in the intensity of light received by the photomultiplier means within a time period. ### Claim 51 (depends on 37) The method of claim 37 including converting said radiation into said electrical pulses by a self-scanning array of photodiodes. ### Claim 52 (depends on 45) The method of claim 45 including storing said count as digitized signals. ### Claim 53 (depends on 46) The method of claim 46 including amplifying the electrical pulses emitted by said discriminator means prior to introducing said pulses into said pulse counter. ### Claim 54 (depends on 30) The method of claim 30 including employing radiation not passing through said ruling as said radiation transported to said radiation conversion station.