Configuration detecting method and system

• US 4,553,844 A
• Filed: 10/05/1982
• Issued: 11/19/1985
• Est. Priority Date: 10/06/1981
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Oshida, Yoshitada, Nakagawa, Yasuo, Ishige, Kanji
• Primary Examiner(s): ROSENBERGER, RICHARD A
• Application Number:
  US06/432,799
• Time in Patent Office: 1,141 Days
• Field of Search: 356/1, 356/4, 356/376, 356/371
• US Class Current: 356/608
• CPC Class Codes: G01B 11/2518 Projection by scanning of the object

Abstract

Method and system of detecting a configuration of a three-dimensional object, in which use is made of a spot beam to be directed to the object. The spot beam is caused to scan the object in a horizontal direction and the resulting spot image is detected through observation in a direction transverse to the horizontal direction. The system includes a laser light source, two Fourier transformation lenses having their Fourier transformation planes intersecting each other on the optical axes of the lenses on a light deflector, a photoelectric converter provided on the object plane of one of the lenses, the laser light source being disposed on the same meridian as the converter, and at least one reflecting mirror provided for forming a real image of the spot of the beam on the object.

Claims

1. A configuration detecting method comprising the steps of passing a laser beam from a laser beam source into a first Fourier transformation lens, reflecting said transformed laser beam by a light deflector, passing said reflected light beam into a second Fourier transformation lens for Fourier inverse transformation, reflecting said inversely-transformed laser beam by a first reflecting mirror to form a laser beam spot on an object to be checked, passing said spot beam into said second lens in the form of a light beam by means of a second reflecting mirror, and passing said spot beam from said second lens into said first lens in the form of a light beam by means of said deflector to form a real image of the laser spot on a photoelectric converter.

2. A configuration detecting method according to claim 1, wherein the laser beam source generates a spot-like laser beam, and the photoelectric converter is a linear image sensor.

3. A configuration detecting method according to claim 2, wherein the first and second Fourier transformation lenses are arranged so that Fourier transformation planes of the lenses intersect each other on optical axes of both lenses, the light deflector being disposed along a line defined by the intersection of the Fourier transformation planes.

4. A configuration detecting method according to claim 3, wherein the light deflector includes a galvano-mirror.

5. A configuration detecting system comprising a laser beam source means for generating a laser beam, a first Fourier transformation lens for receiving the generated laser beam and for transforming the generated laser beam, a light deflector means arranged for reflecting the transformed laser beam from the first Fourier transformation lens, a second Fourier transformation lens for receiving the reflected transformed laser beam and for providing a Fourier inverse transformation thereof, a first reflecting mirror means for reflecting the inversely-transformed laser beam so as to form a laser beam spot on an object to be checked, means for passing light from said laser beam spot on the object to be checked into said second Fourier transformation lens as a light beam, said light deflector means receiving the light beam of said laser spot beam passing through said second Fourier transformation lens and for deflecting said light beam into said first lens so as to form a real image of the laser spot on a photoelectric converter means.

6. A configuration detecting system according to claim 5, wherein said first and second Fourier transformation lenses are arranged so that Fourier transformation planes of both lenses intersect on optical axes of both lenses, said deflector means being arranged along a line of intersection of the Fourier transformation planes of both lenses.

7. A configuration detecting system according to claim 6, wherein said laser beam from said laser beam source passes through said first and second Fourier transformation lenses in one direction and light of the laser beam spot on the object to be checked passes through said second and said first Fourier transformation lenses in an opposite direction.

8. A configuration detecting system according to claim 6, wherein said photoelectric converter means includes a linear image sensor, said linear image sensor being provided on an object plane of said first Fourier transformation lens and said laser beam source being provided on the same meridian as said linear image sensor.

9. A configuration detecting system according to claim 6, wherein said means for passing light from the laser beam spot into said second Fourier transformation lens includes a second reflecting mirror.

10. A configuration detecting system according to claim 9, wherein said first and second reflecting mirrors are arranged symmetrically with respect to the optical axes of said second Fourier transformation lens.

11. A configuration detecting system according to claim 6, wherein said light deflector means includes a galvano-mirror.