Multiaxis laser interferometry distance measuring device

• US 5,828,456 A
• Filed: 10/21/1996
• Issued: 10/27/1998
• Est. Priority Date: 11/15/1995
• Status: Expired due to Fees

• Current Assignee: Sokkia Co. Ltd. (Topcon Corporation)
• Original Assignee: Sokkia Co. Ltd. (Topcon Corporation)
• Inventors: Tanaka, Kazunori, Aoki, Tatsuya
• Primary Examiner(s): Kim, Robert
• Application Number:
  US08/734,070
• Time in Patent Office: 736 Days
• Field of Search: 356/345, 356/358, 356/351
• US Class Current: 356/500
• CPC Class Codes: G01B 11/002 for measuring two or more coordinates
• CPC Class Codes: G01B 2290/70 Using polarization in the interferometer
• CPC Class Codes: G01B 9/02021 contacting different faces of object, e.g. opposite faces
• CPC Class Codes: G01B 9/02049 characterised by particular mechanical design details

Abstract

Interferometer 14 is equipped with a beam directing mechanism portion for causing the incoming laser beam to be reflected in the x, y, and z axis directions and a switching mechanism for the beam directing mechanism portion. Computer 20 provides driving commands sequentially to NC controller 22 in accordance with the contents of a measurement program to thereby operate milling machine A in accordance with a prescribed procedure, calculates correction data by comparing the distance measurement data, obtained at the beam source portion 12, with reference data, causes the correction value to be taken into NC controller 22, and starts up controller 24 and operates the switching mechanism of the multiaxis interferometer 14 after the end of work for each axis to change the axial direction measured.

Claims

1. A multiaxis laser distance measuring device comprising:

a beam source portion for emitting a laser beam,

a multiaxis interferometer equipped with an interferometer body having a stage that is linearly or rotatable movable, and a beam directing mechanism set onto said stage for splitting the incoming laser beam and directing the beam toward either the orthogonal x, y, or z axes of an NC machine tool, and transmitting the interference beam resulting from the interference of the measuring beam with the reference beam, and a switching mechanism for controlling movement of the stage to move the beam directing mechanism into a position that directs said beam along either said x, y, or z axes,

an optical fiber, which is disposed between the beam source portion and the interferometer body for guiding the laser beam from the beam source portion to the interferometer body,

a plurality of reflecting targets which are fixed on the measurement positions of the NC machine tool for receiving the laser beam projected in the x, y, or z axis direction and reflecting the beam back towards the interferometer body,

a beam receiving portion for receiving the interference beam from the interferometer body,

a controller for controlling the switching mechanism, and

a control unit for operating the NC machine tool in the x, y, and z axis directions in accordance with a prescribed procedure, and comparing the distance measurement data obtained by the beam receiving portion at the beam source portion with priorly set reference data to provide the NC machine tool with correction values, and commanding a switching operation to the controller each time the measurements for one of the axes, x, y, and z, have been completed.

2. The multiaxis laser distance measuring device set forth in claim 1, wherein:

the multiaxis interferometer comprises;

a casing having an entrance window portion which faces the optical fiber and an exit window portion which faces the beam receiving portion, and wherein said

state is disposed inside the casing in a linearly movable or rotatably movable manner so that it may face the entrance/exit window portion,

and the switching mechanism comprises;

a moving mechanism for moving the stage linearly or rotatably to cause the beam directing mechanism portion to face the entrance/exit window portion, and

a detection means for detecting a stoppage position of the stage.

3. The multiaxis laser distance measuring device set forth in claim 2, wherein:

the interferometer body is equipped with an interferometry portion which is disposed along the movement direction of the moving mechanism and is fixed and set on the stage, and said beam directing mechanism which is set on the stage and to the rear of the interferometry portion, and wherein

the beam directing mechanism has a portion for causing the incoming beam from the interferometry portion to propagate rectilinearly, a portion for reflecting the incoming beam from the interferometry portion upward or downward, and a portion for reflecting the incoming beam from the interferometry portion to the side.

4. The multiaxis laser distance measuring device set forth in claim 2, wherein:

the interferometer body is provided with the interferometry portion being fixed and set on the rear side of the entrance/exit window portion and with the beam directing mechanism portion being set on the stage side, and

the beam directing mechanism has a portion for causing the incoming beam from the interferometry portion to propagate rectilinearly, a portion for reflecting the incoming beam from the interferometry portion upward or downward, and a portion for reflecting the incoming beam from the interferometry portion to the side.

5. The multiaxis laser distance measuring device set forth in claim 1, wherein:

the multiaxis interferometer comprises;

a casing having an entrance window portion which faces the optical fiber and an exit window portion which faces the beam receiving portion, and wherein said

stage is disposed inside the casing in a linearly movable manner so that it may face the entrance/exit window portion, and said

interferometer body has an interferometry portion for causing the incident laser beam to be projected in the x, y, z axis direction,

and the switching mechanism comprises;

a moving mechanism for moving the stage linearly to cause the interferometry portion to face the entrance/exit window portion, and

a detection means for detecting a stoppage position of the stage.