Method for measuring distances and apparatus for performing the method

• US 4,325,639 A
• Filed: 02/04/1980
• Issued: 04/20/1982
• Est. Priority Date: 02/04/1980
• Status: Expired due to Term

• Current Assignee: H A Schlatter AG
• Original Assignee: H A Schlatter AG
• Inventors: Richter, Hans
• Primary Examiner(s): ROSENBERGER, RICHARD A
• Application Number:
  US06/117,994
• Time in Patent Office: 806 Days
• Field of Search: 356/1, 356/4, 356/373, 356/376, 356/375
• US Class Current: 356/608
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures

Abstract

A method for measuring distances and for determining the three-dimensional contour of a workpiece, wherein two intersecting light beams are directed onto the workpiece, the light points produced by the beams on the workpiece surface are determined and the angle of inclination of the striking beam in the common plane thereof is measured.

Claims

1. A method for measuring distances and for determining the three-dimensional contour of a workpiece comprising directing two light beams of different wavelengths onto the workpiece, pivoting the beams in their common plane, pivoting the common plane around an axis which is common to said plane, measuring the angles of inclination of the lightpoints produced by the beams on the workpiece surface in the different wavelengths, determining the position of the image of each light point and calculating the distances and the contour using the angles of inclination and the positions of the images.

2. A method for measuring distances and for determining the three-dimensional contour of a workpiece comprising directing two light beams onto the workpiece, pivoting the beams in their common plane with different velocities, pivoting the common plane around an axis which is common to said plane, measuring the angles of inclination of each beam in the common plane when the beams intersect on the workpiece surface, determining the position of the image of the intersection lightpoint produced by the beams on the workpiece surface and calculating the distances and the contour using the angles of inclination and the position of the image of the intersection lightpoint.

3. An apparatus for measuring distances and for determining the three-dimensional contour of a workpiece comprising means for directing a pair of light beams of different wavelengths onto the workpiece, a pair of spaced mirrors, each adapted to reflect one of the beams, means for swivelling the mirrors to change the angles of the mirrors, a collecting optic for collecting the images of the light points produced by said beams on the workpiece surface, a semi-transparent mirror arranged behind the collecting optic for permitting the passage of a part of the light to a first screen, sensitive to light of one of the wavelengths and reflecting another part of the light to a second screen, sensitive to the light of the other wavelength, and means for determining the angles of the mirrors.

5. An apparatus according to claim 3 wherein said means for swivelling is a common mechanism for swivelling the mirrors.

6. An apparatus according to one of the claims 3 or 4, including a further swivelling mirror for deflecting the beams from said pair of mirrors, and means for measuring the position of the further mirror.

7. An apparatus accordong to one of the claims 3 or 4, in which the beams are laser beams.

8. An apparatus according to claim 3 further including two laser beam generators for generating said light beams, each with a different wavelength.

10. An apparatus according to one of the claims 3 or 4, in which the screen is a photodiode array.

11. An apparatus according to claim 3, further including a filter in front of each of the screens, one filter permitting the passage of light of one wavelength and the other permitting the passage of light of the other wavelength.

4. An apparatus for measuring distances and for determining the three-dimensional contour of a workpiece comprising means for directing a pair of lightbeams onto the workpiece, a pair of spaced mirrors, each adapted to reflect one of the beams, separate swivelling mechanisms for swivelling the mirrors to change the angles of the mirrors with different velocities, a collecting optic for collecting the images of the lightpoints produced by said beams on the workpiece surface, a screen arranged behind the collecting optic and means for determining the angles of the mirrors when a single lightpoint is imaged on the screen.

9. An apparatus according to claim 4, further including one laser beam generator for generating a single source beam, and a fixed semitransparent mirror for splitting the source beam into said pair of light beams located between the generator and two other mirrors.