Multi-coordinate measuring machine

• US 4,647,206 A
• Filed: 09/18/1984
• Issued: 03/03/1987
• Est. Priority Date: 09/23/1983
• Status: Expired due to Term

• Current Assignee: Carl-Zeiss-Stiftung
• Original Assignee: Carl-Zeiss-Stiftung
• Inventors: Kunzmann, Horst, Schepperle, Karl, Trieb, Gerhard
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US06/651,592
• Time in Patent Office: 896 Days
• Field of Search: 356/358, 250/227, 350/96.33
• US Class Current: 356/500
• CPC Class Codes: G01B 11/005 coordinate measuring machines
• CPC Class Codes: G01B 2290/45 Multiple detectors for detecting interferometer signals
• CPC Class Codes: G01B 9/02027 Two or more interferometric channels or interferometers

Abstract

The invention contemplates a multi-coordinate measuring machine with interferometric detection of the path of displacement in each of the measurement axes.

Each measurement axis is provided with at least one interferometer head which consists of a beam splitter, reference mirror and photoelectric detector. The interferometer heads are supplied by a monomode fiber from a single stationary laser generator.

Claims

1. A multi-coordinate measuring machine with interferometric detection of the path of displacement in each of a plurality of measurement axes, characterized by the fact that for each of the plural measurement axes a complete interferometer head is carried by said machine and is dedicated solely to measurement along its one of the plural axes;

said interferometer head in each case comprising a first beam splitter with two outlet beams produced after interference at the beam-splitting layer of said first beam splitter, a separate polarizing beam splitter disposed at each of said outlets to split each of said outlet beams into its two linearly polarized components, a separate photoelectric detector carried with said interfereometer head at each of the two outlets of each of said polarizing beam splitters, whereby to enable electric-signal data for counting of interference lines; and

a polarized beam supply comprising a single fixedly mounted laser generator, and a separate flexible light guide coupling the output of said laser generator to each said interferometer head, each said light guide being a monomode fiber of polarization-maintaining type.

2. A multi-coordinate measuring machine according to claim 1, characterized by the fact that a separate optical system is positioned to couple each beam-split fraction to a different one of said light guides (8, 9, 10), each said optical system focusing individual laser-generated rays on the transmission end of a different one of said light guides (8, 9, 10).

3. A multi-coordinate measuring machine according to claim 1, characterized by the fact that the light guides (8, 9, 10) are, at least in part, combined with the signal or supply lines of the detectors (18 to 21) to form a common cable harness.

4. In a multiple-coordinate measuring machine comprising a plurality of displaceable parts wherein the directions of displacement are orthogonally related and establish an orthogonally related set of different measurement axes, there being one complete interferometric length-measuring head and mirror carried by said machine and adapted to each measuring axis;

each said interferometric head comprising a first beam splitter with two outlet beams produced ater interference at the beam-splitting layer of said first beam splitter, a separate polarizing beam splitter disposed at each of said outlet beams to split each of said outlet beams into its two linearly polarized components, a separate photoelectric detector carried with said interferometer head at each of the two outlets of each of said polarizing beam splitters, whereby to enable electric-signal data for counting of interference lines; and

a polarized beam supply for each of said interferometer heads, said beam supply comprising a single fixedly mounted laser generator, beam-splitting means for developing from said single laser generator a plurality of derived sources of polarized beam supply, a separate flexible light guide coupling each derived source to a different one of said interferometer heads, each said light guide being a monomode fiber of polarization type, and flexible wiring connected to said photoelectric detectors and combined with said light guides in a common cable harness.