Laser reference level setting device

• US 6,262,801 B1
• Filed: 09/14/1998
• Issued: 07/17/2001
• Est. Priority Date: 05/25/1995
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Topcon
• Original Assignee: Kabushiki Kaisha Topcon
• Inventors: Adegawa, Toshikazu, Shibuya, Hiroto
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US09/152,876
• Time in Patent Office: 1,037 Days
• Field of Search: 356/141.1, 356/152--15, 356/139-4-1, 356/139.1, 356/4.03, 356/3.09
• US Class Current: 356/139.08
• CPC Class Codes: E03B 7/00 Water main or service pipe systems pipes or tubes in general F16L
• CPC Class Codes: E03F 3/06 Methods of, or installations for, laying sewer pipes making pipes in situ F16L1/038 ; laying conduits in association with the digging of a trench E02F5/10; laying pipes in general F16L1/00
• CPC Class Codes: E03F 7/00 Other installations or implements for operating sewer systems, e.g. for preventing or indicating stoppage; Emptying cesspools
• CPC Class Codes: E03F 7/12 Installations enabling inspection personnel to drive along sewer canals
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105

Abstract

The present invention provides a laser reference level setting device, by which it is possible to adjust irradiating positions of a laser beam in vertical and horizontal directions with a simple arrangement and without additional manpower and to measure a tilt angle. The device comprises a laser sighting device and a target, the target having a reflection surface for indicating a given position on the target, and the laser sighting device comprising a laser oscillating device having an emitting means rotatably supported and for emitting a laser beam and a light receiving means for receiving a reflection laser beam, a driving unit for rotating at least the laser beam emitting means of the laser oscillating device, and a control unit for controlling the driving unit to direct the laser beam to a given position on the target according to the light receiving condition of the reflected laser beam reflected from the reflection surface of the target.

Claims

1. A laser reference level setting device, comprising a laser beam emitting means rotatably supported for emitting a laser beam toward a target having a reflection surface for indicating a given position thereon, a light receiving means for receiving a reflection laser beam from said target, a driving unit for rotating said laser beam emitting means in upward and downward directions and in left and right directions toward an irradiating direction, a control unit for calculating the irradiating position of the laser beam on the target according to a light receiving condition of said light receiving means about said reflection light beam from said reflection surfaces of said target and for controlling said driving unit so as to direct the laser beam to a given position on the target based on a result of said calculation, a tilt sensor which is rotatably supported in said upward and downward directions with respect to said laser beam emitting means and detects a horizontal position, a tilt angle detecting means for detecting an upward and downward rotating angle between said laser beam emitting means and said tilt sensor, and a display unit for displaying said upward and downward rotating angle as a tilt angle of said laser beam when said tilt sensor is made in a horizontal position.

2. A laser reference level setting device according to claim 1, further comprising horizontal angle detecting means for detecting a horizontal rotating angle of said laser beam emitting means and wherein said display unit further displays a horizontal angle of said laser beam based on the detection of said horizontal angle detecting means when said laser beam is directed to said given position on said target.

3. A laser reference level setting device according to claim 1, wherein said target has said reflection surfaces for indicating said given position said surfaces being arranged at symmetrical positions in vertical and horizontal directions.

4. A laser reference level setting device according to claim 1, wherein said target has a reflection pattern which indicates said given position only by being scanned in a horizontal direction.

5. A laser reference level setting device according to claim 3, wherein said control unit calculates the position of the weighted center of said light receiving signal and the center of said target is obtained from the position of said weighted center.

6. A laser reference level setting device according to claim 4, wherein said control unit calculates a pulse width of said light receiving signal and the center of said target is obtained from said pulse width.

7. A laser reference level setting device according to claim 1, wherein said control unit calculates a scan rotating angle of the laser beam based on a pulse width of said light receiving signal and a distance from said laser beam emitting means to said target is measured based on the known dimension between said reflection surfaces corresponding to said scan rotating angle and said pulse width.