Surveying system

• US 5,995,233 A
• Filed: 01/29/1997
• Issued: 11/30/1999
• Est. Priority Date: 06/21/1994
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon
• Inventors: Nishizawa, Hiroyuki, Tokuda, Yoshikatsu, Adegawa, Toshikazu, Ohtomo, Fumio, Yoshino, Ken-ichiro
• Primary Examiner(s): HANTIS, KAREN
• Application Number:
  US08/790,631
• Time in Patent Office: 1,035 Days
• Field of Search: 356/3.02-3.08, 356/3.1, 356/3.12-3.16, 356/4.02-4.07, 356/4.09-4.1, 356/5.01-5.13, 356/5.15, 356/141.2-141.5 , 356/142-148, 356/152.1-152.3, 356/153
• US Class Current: 356/400
• CPC Class Codes: G01C 15/006 Detectors therefor

Abstract

A surveying system which comprises a light source section for emitting laser beam, a rotational portion for rotating the laser beam from the light source in horizontal direction, a light source driving section for driving the light source unit, a survey instrument main unit having a light receiving unit for receiving the reflected laser beam, and a reflecting object for reflecting the laser beam irradiated from the survey instrument main unit main unit of the survey instrument.

Claims

1. A surveying system, comprising a survey instrument main unit for emitting a laser beam and a reflecting object for reflecting toward said survey instrument main unit the laser beam;

said survey system main unit having a light source section for emitting said laser beam, a rotational portion for rotating the laser beam from said light source section, a light receiving portion for receiving the laser beam reflected from said reflecting object, a distance measuring section for measuring distance between said survey instrument main unit and said reflecting object based on output from said light receiving portion, a position control portion for controlling an emitting position of the laser beam based on output of light receiving portion, a light source driving section for driving the light source section, and said light source driving section for simultaneously modulating the laser beam at a predetermined frequency in order to measure the distance and for shifting the phase of said modulated laser beam at every predetermined number of cycles according to communication data to be transmitted in order to transmit said communication data to said reflecting object.

2. A surveying system according to claim 1, wherein said survey instrument main unit comprises a polarizing means for changing the laser beam to a predetermined polarizing laser beam, and the laser beam emitted from said survey instrument main unit is said polarized laser beam.

3. A surveying system according to claim 1, wherein said reflecting object comprises a reflection portion for reflecting the laser beam from said light source section, a light receiving means for receiving the laser beam having said shifted phase from said light source section and for detecting said communication data based on the shifted phase and a display portion for displaying said detected communication data, and said reflection portion consists of a retro-reflection member and a birefrigence member to produce a phase difference.

4. A surveying system according to claim 1, wherein said distance measuring section detects the shifted phase of the reflected laser beam received by said light receiving portion at every said predetermined number of cycles, adjusts a sampling timing so as to demodulate the shifted phase, samples or accumulates after sampling, and measures the distance to said reflecting object based on a modulated signal obtained by sampling or a modulated signal obtained by accumulating after sampling.

5. A surveying system according to claim 1 or claim 3, wherein said communication data are expressed by binarized signal including distance data measured by said distance measuring section, and said light source driving section shifts the phase of one portion of said binarized signal to 0°

phase and the phase of the other portion of said binarized signal to 180°

phase and changes modulation status of said laser beam.

6. A surveying instrument according to claim 1, wherein said distance measuring section performs Fourier transform on the sampled said output from said light receiving portion or the sampled and accumulated output and detects the phase thereof.

7. A surveying system according to claim 1, wherein a predetermined polarizing direction is given to the laser beam emitted from said light source section, said reflecting object has reflecting surface formed by two polarizing members with different polarizing properties, and said reflecting object is detected according to the laser beam reflected by said reflecting object and having a predetermined polarized light.