Method for determination of the level of two or more measurement points, and an arrangement for this purpose

• US 7,212,294 B2
• Filed: 04/28/2004
• Issued: 05/01/2007
• Est. Priority Date: 04/29/2003
• Status: Expired due to Fees

• Current Assignee: PRÜFTECHNIK Dieter Busch AG (Fortive Corp.)
• Original Assignee: PRÜFTECHNIK Dieter Busch AG (Fortive Corp.)
• Inventors: Stroel, Klaus
• Primary Examiner(s): Nguyen; Sang H.
• Application Number:
  US10/833,349
• Publication Number:
  US 20050002044A1
• Time in Patent Office: 1,098 Days
• Field of Search: 356614-622, 356/139.07, 356 401- 515, 356/141.1, 3561521-152, 250/203.2, 332/91, 332/81, 332/86, 359/668
• US Class Current: 356/622
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

A method and arrangement for determining the level of at least two measurement points with a light beam direct along a first direction and being deflected through 90° with respect to the first direction to a second direction, the second direction being rotated through a rotation angle corresponding to the position of the measurement point about an axis which is formed by the first direction. The light beam has a cross-sectional intensity distribution with a preferred direction, and after being deflected to the second direction, falls on a detector surface which is positioned successively at each measurement point, the incidence level of the light beam and the orientation of the preferred direction of the cross-section intensity distribution of the light beam on the detector surface being determined for each measurement point, and the rotation angle for each measurement point being determined from the respective orientation of the preferred direction on the detector surface.

Claims

1. A method for determination of the level of at least two measurement points with respect to each other, comprising the steps of:

producing a light beam having a cross-sectional intensity distribution with a preferred direction and directing the light beam in a first direction,

deflecting the light beam through 90°

with respect to the first direction to a second direction, with the second direction being rotated through a rotation angle corresponding to a position of the measurement point about an axis formed by the first direction,

receiving the light beam deflected to the second direction on a detector surface which is positioned successively at each measurement point by movement of the detector surface and without changing the position at which the light beam is deflected,

determining the incidence level of the light beam and the orientation of the preferred direction of the cross-sectional intensity distribution of the light beam on the detector surface for each measurement point,

determining the rotation angle for each measurement point from the respective orientation of the preferred direction on the detector surface; and

determining the level of the measurement points with respect to each other based upon the incidence level and rotational angle determined for each measurement point on the detector surface itself.

2. The method as claimed in claim 1, wherein the incidence level of the measurement points is determined as a distance relative to a reference plane, with the first direction being at right angles to the reference plane.

3. The method as claimed in claim 1, wherein the reference plane is determined as a compensation plane relative to the measured levels of the measurement points.

4. The method as claimed in claim 1, wherein a lens system or an aperture is positioned between the light source and the detector in order to produce the preferred direction of the cross-sectional intensity distribution of the light beam.

5. The method as claimed in claim 1, wherein a semiconductor laser, whose light intensity in the far field has a preferred direction of the cross-sectional intensity distribution, is used as the light source.

6. The method as claimed in claim 1, wherein the detector is an area sensor.

7. An arrangement for determination of the level of at least two measurement points (29, 30), having a detector surface (26) and having a light source (16) which is designed to produce a light beam along a first direction (16), having a fixed deflection device (10) in order to deflect the light beam through 90°

with respect to the first direction to a second direction (20), in which case the deflection device can be rotated about an axis (12) which is formed by the first direction in order to rotate the second direction to correspond to the position of the respective measurement point, wherein the light beam has a cross-section intensity distribution (40) with a preferred direction (42) and, after being deflected to the second direction, falls on the detector surface (26), which is movable successively to each measurement point (29, 30), and with the detector surface being designed to determine the incidence level of the light beam and the orientation of the preferred direction of the cross-section intensity distribution of the light beam on the detector surface for each measurement point.

8. The arrangement as claimed in claim 7, wherein the deflection device comprises one of a pentagonal prism, a mirror and a group of fibers.

9. The arrangement as claimed in claim 7, wherein the detector surface is an image detection sensor having at least two columns and rows of light-sensitive elements.

10. The arrangement as claimed in claim 9, wherein the image detection sensor is one of a CCD chip and a CMOS sensor.

11. The arrangement as claimed in claim 7, wherein the light source is a laser.

12. The arrangement as claimed in claim 11, wherein the light source is a laser diode, with the light beam having an elliptical cross-section intensity distribution in the far field of the laser diode.

13. The arrangement as claimed in claim 7, wherein a lens system having at least one cylindrical lens is located between the light source and the deflection device (10).

14. The arrangement as claimed in claim 7, wherein at least one optical element with an opening that is not radially symmetrical is located between the light source and the deflection device.

15. The arrangement as claimed in claim 14, wherein the opening is not centrally symmetrical.