Automatic tracking apparatus for reflector

• US 7,072,032 B2
• Filed: 11/20/2003
• Issued: 07/04/2006
• Est. Priority Date: 11/22/2002
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon
• Inventors: Saito, Masahiro, Kumagai, Kaoru, Yamaguchi, Shinji
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): Ratcliffe, Luke D.
• Application Number:
  US10/718,230
• Publication Number:
  US 20040100628A1
• Time in Patent Office: 957 Days
• Field of Search: 356/3.01, 356/8, 356/300, 356/121, 356/122, 356/125, 356/622, 356/139.08, 356/4.03, 356/28, 356/28.5, 566/34
• US Class Current: 356/139.08
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

The present invention comprises an illumination portion (11), a light receiving portion (12), disposed in the surveying machine body (8), having an image sensor (27) for receiving a reflection light image (MO) of the measurement light, arithmetic means (38) for calculating a position in an area of the image sensor (27) for the reflection light image (MO) from a reflector (2), and a rotation mechanism for rotating the surveying machine body (8) so as to position the reflector (2) on a light receiving optical axis of the light receiving portion (12) based on the position obtained by the arithmetic means (38), and the light receiving portion (12) is provided with a light receiving sensor (47) having a smaller area than the area of the image sensor (27) on the light receiving optical axis in a conjugated position with the image area (27), and the arithmetic means (38) distinguishes the reflector 2 based on an output of the light receiving sensor (47).

Claims

1. An automatic tracking apparatus for a reflector comprising:

a surveying machine body;

an illumination portion, which is disposed in said surveying machine body, and illuminates a measurement light of a modulated measurement light toward a reflector;

a light receiving portion, which is disposed in said surveying machine body, and has an image sensor for receiving a reflection light image of the measurement light illuminated toward said reflector;

an arithmetic device configured to calculate a position of the reflection light image from said reflector in an area of said image sensor; and

a rotation mechanism, which rotates said surveying machine body such that the position of the reflection light image obtained by said arithmetic device becomes a center of the image sensor,

wherein said light receiving portion is provided with a light receiving sensor, which has a smaller area than the area of said image sensor, and is disposed in a conjugated position with the image sensor on a light receiving optical axis of the light receiving portion, so as to receive a quantity of light in a vicinity area including an image center of the image sensor, and a synchronization detecting circuit which detects an output of the light receiving sensor in synchronization with the modulated measurement light, and

said arithmetic device determines the reflection light image from the reflector if the synchronization detecting circuit detects that a modulated frequency of the modulated measurement light coincides with a frequency of the output of the light receiving sensor, and rotates the rotation mechanism based on the determination to track the reflector.

2. The automatic tracking apparatus for a reflector according to claim 1, wherein said image sensor and said light receiving sensor are disposed in the conjugated position through a beam splitter.

3. The automatic tracking apparatus for a reflector according to claim 1, wherein said illumination portion emits a modulated pulsed light, which is the measurement light, in an accumulation time during one field of said image sensor, and the arithmetic device detects the position of the modulated pulsed light received by the image sensor, and distinguishes the reflection light image of the reflector from the light image other than the reflection light image of the reflector.