Position determining apparatus

1. An apparatus for determining positions, comprising:

(a) a rotary laser apparatus for emitting two or more fan-shaped laser beams, said rotary laser apparatus including a laser projector and a rotary unit rotating relative to said laser projector, wherein:

said laser projector has:

(1) a first laser illuminator for emitting a first linearly polarized laser beam;

(2) a second laser illuminator for emitting a second linearly polarized laser beam;

(3) a first polarized beam splitter for directing the laser beams emitted from said first laser illuminator and said second laser illuminator in the same direction; and

(4) a first one-quarter wave plate for converting said first and second linearly polarized laser beams from said first polarized beam splitter into circularly polarized laser beams; and said rotary unit has:

(1) a second one-quarter wave plate for converting the circularly polarized laser beams from said first one-quarter wave plate into linearly polarized laser beams;

(2) a second polarized beam splitter for splitting the linearly polarized laser beams from said second one-quarter wave plate;

(3) a third one-quarter wave plate for converting the laser beams split and reflected by said second polarized beam splitter into circularly polarized laser beam;

(4) a first cylinder mirror for converting the circularly polarized laser beam from said third one-quarter wave plate into a first fan-shaped laser beam and reflecting back and emitting said fan-shaped laser beam through said third one-quarter wave plate and said second polarized beam splitter;

(5) a fourth one-quarter wave plate for converting laser beams transmitted through said second polarized beam splitter into a circularly polarized laser beam; and

(6) a second cylinder mirror for converting said circularly polarized laser beam from said fourth one-quarter wave plate into a second fan-shaped laser beam and reflecting back and emitting said second fan-shaped laser beam through said fourth one-quarter wave plate and said second polarized beam splitter; and

(b) optical sensor means for receiving the fan-shaped laser beams to determine a position.

2. An apparatus for determining positions according to claim 1 , wherein said rotary unit further includes a deflecting prism between said third one-quarter wave plate and said first cylinder mirror and said rotary laser apparatus emits three fan-shaped laser beams.

3. An apparatus for determining positions according to claim 1 , wherein said fist and second cylinder mirrors are oriented so that the first and second fan-shaped laser beams emitted from said rotary laser apparatus are inclined relative to the horizontal plane respectively.

4. An apparatus for determining positions according to claim 1 , wherein said rotary laser apparatus emits fan-shaped laser beams of different polarized direction by 90°.

5. An apparatus for determining positions according to claim 1 , wherein said rotary laser apparatus emits fan-shaped laser beams modulated into different frequencies to distinguish these fan-shaped laser beams.

6. An apparatus for determining positions according to claims 1 , wherein said rotary laser apparatus emits fan-shaped laser beams of different wavelengths to distinguish the fan-shaped laser beams.

7. An apparatus for determining positions according to claim 1 , wherein said optical sensor further includes a GPS (global positioning system) position sensor that detects the relative position of said optical sensor to said rotary laser apparatus.

8. An apparatus for determining positions, comprising:

(a) a rotary laser apparatus for emitting two or more fan-shaped laser beams, said rotary laser apparatus including a laser projector and a rotary unit rotating relative to said laser projector, wherein

said laser projector has:

(1) a laser illuminator; and

(2) collimator lens means for collimating the laser beam emitted from said laser illuminator; and

said rotary unit has:

(1) beam expanders for receiving the laser beam collimated by said collimator lens;

(2) cylindrical lenses for converting the laser beams from said beam expanders into fan-shaped laser beams; and

(3) mirrors for reflecting the fan-shaped laser beams and emitting the fan-shaped laser beams from said rotary laser apparatus; and

(b) optical sensor means for receiving the fan-shaped laser beams to determine a position.

9. An apparatus for determining positions, comprising:

(a) a rotary laser apparatus for emitting two or more fan-shaped laser beams, said rotary laser apparatus including a laser projector and a rotary unit rotating relative to said laser projector, wherein:

said laser projector has:

(1) a laser illuminator and

(2) a collimator lens for collimating the laser beam emitted from said laser illuminator; and

said rotary unit has:

(1) a shield mask having at least three apertures;

(2) a first cylindrical lens for converting the laser beams passing through at least two of said apertures into fan-shaped laser beams;

(3) a wedge prism for deflecting the fan-shaped laser beams from said first cylindrical lens and emitting the fan-shaped laser beams from said rotary laser apparatus; and

(4) a second cylindrical lens for converting the laser beams passing through at least one of said apertures into fan-shaped laser beams and emitting the fan-shaped laser beams from said rotary laser apparatus; and

(b) optical sensor means for receiving the fan-shaped laser beams to determine a position.