Laser surveying system

{
  "publication_number": "US5589939A",
  "country": "US",
  "kind": "A",
  "title": "Laser surveying system",
  "abstract": "Disclosed is a laser surveying system in which devices installed at measuring points are inexpensive and small in weight, and a distribution of codes is not needed for transmitting positional data obtained, this system being capable of continuously quickly making a three-dimensional measurement of the displacement. When the laser beam projected from a light projector sweeps a reflecting device on an object, reflecting surfaces supply the laser beam with positional data. A displacement of the object is measured based on the transmitted positional data from the reflected laser beam.",
  "claims": [
    "1. A laser surveying system comprising: a light projector which projects a laser beam in a direction that rotates around a rotational axis and within a plane perpendicular to said rotational axis to sweep an object; an angle detector to detect a rotational angle, at which said laser beam is being projected, substantially continuously throughout a sweep range of said laser beam; a reflector to be provided on the object and including means for converting said laser beam into a reflected laser beam containing two-dimensional positional data; and a light receiving unit which receives the reflected laser beam and generates an output indicating a three-dimensional position of the reflector based on the rotational angle detected by said angle detector and the two-dimensional positional data contained in the reflected laser beam.",
    "2. A laser surveying system according to claim 1, further comprising a position computer for determining the three-dimensional position of the reflector based on the output from said light receiving unit.",
    "3. A laser surveying system according to claim 1, wherein said reflector further includes a reflecting plate having at least a pair of edges, a spacing therebetween continuously changing along a direction intersecting said plane.",
    "4. A laser surveying system according to claim 3, wherein said two-dimensional positional data includes data about a time-interval over which the laser beam traverses the pair of edges.",
    "5. A laser surveying system according to claim 4, further comprising: a time-interval measuring unit for measuring the time-interval based on the data about the time-interval; and a position computer for determining the three-dimensional position of the reflector based on the measured time-interval.",
    "6. A laser surveying system according to claim 3, wherein said two-dimensional positional data includes data about a light quantity of the reflected laser beam when the laser beam traverses the pair of edges.",
    "7. A laser surveying system according to claim 1, wherein said reflector includes a first reflecting area of which the spacing between a pair of edges increases along one direction intersecting said plane and a second reflecting area of which the spacing between a pair of edges increases along a direction opposite to said one direction.",
    "8. A laser surveying system according to claim 1, wherein said reflector further includes: a light receiving device for generating an output upon receiving said laser beam at a predetermined position within a positional range defined by said converting means; and a display unit that responds to the output of said light receiving device.",
    "9. A laser surveying system according to claim 1, wherein said reflector further includes: a light receiving device for generating an output upon receiving said laser beam at a predetermined position outside of a positional range defined by said converting means; and a display unit that responds to the output of said light receiving device.",
    "10. A laser surveying system according to claim 1, further comprising a housing which accommodates said light projector and said light receiving unit.",
    "11. A laser surveying system comprising: a light projector which projects a laser beam to sweep an object; a reflector to be provided on the object and including means for converting said laser beam into a reflected laser beam containing positional data in an intersecting direction intersecting a sweeping direction of said laser beam, said reflector further including a light receiving element to receive said laser beam at a predetermined position within a positional range defined by said converting means, and an indicator which responds to an output from said light receiving element; and a light receiving unit which receives the reflected laser beam and generates an output indicating a position of the reflector in the intersecting direction based on the positional data.",
    "12. A laser surveying system comprising: a light projector which projects a laser beam to sweep an object; a reflector to be provided on the object and including means for converting said laser beam into a reflected laser beam containing positional data in an intersecting direction intersecting a sweeping direction of said laser beam, said reflector further including a light receiving element to receive said laser beam at a predetermined position outside of a positional range defined by said converting means, and an indicator which responds to an output from said light receiving element; and a light receiving unit which receives the reflected laser beam and generates an output indicating a position of the reflector in the intersecting direction based on the positional data.",
    "13. A laser surveying system comprising: a light projector which projects a laser beam in a direction that rotates around a rotational axis and within a plane perpendicular to said rotational axis to sweep an object; an angle detector to detect a rotational angle, at which said laser beam is being projected, substantially continuously throughout a sweep range of said laser beam; at least one reflector to be provided on the object and including a transformer for transforming said laser beam into a reflected laser beam containing positional data in an intersecting direction intersecting said plane; and a light receiving unit which receives the reflected laser beam and generates an output indicating a position of the reflector in the intersecting direction and within said plane based on the rotational angle detected by said angle detector and the positional data.",
    "14. A laser surveying system comprising: a light projector which projects a laser beam in a direction that rotates around a rotational axis and within a plane perpendicular to said rotational axis to sweep an object; an angle detector to detect a rotational angle, at which said laser beam is being projected, substantially continuously throughout a sweep range of said laser beam; a plurality of reflectors to be respectively provided at different places on the object, and each including a transformer for transforming said laser beam into a reflected laser beam containing positional data in an intersecting direction intersecting said plane; and a light receiving unit which receives the reflected laser beams and generates an output indicating a position of each of said plurality of reflectors in a rotational direction, based on the corresponding rotational angles detected by said angle detector, and generates an output indicating a position of each of said plurality of reflectors in the intersecting direction, based on the corresponding positional data."
  ],
  "cpc": [
    "G01C 15/004"
  ],
  "assignees": [
    "NIKON CORP"
  ],
  "filing_date": "1996-02-21",
  "publication_date": "1996-12-31",
  "grant_date": "1996-12-31",
  "priority_date": "1993-12-28",
  "application_number": "US-60429496-A",
  "family_id": "18400310",
  "citations": [
    "EP0257525A2",
    "GB2200474A",
    "JPH0456243A",
    "US4997283A",
    "US5251013A"
  ]
}