Particle detector, system and method

1. A method of detecting particles comprising:

emitting a beam of radiation from a light source into a monitored region;

detecting an increase in scattered radiation intensity, from the beam of radiation, in images of the region captured by a camera, the increase in scattered radiation intensity in images of the region indicating the presence of the particles wherein the beam of radiation is adapted to communicate data,

wherein the method includes encoding data for modulating the beam, to communicate data.

2. The method as claimed in claim 1 wherein:

the beam of radiation comprises the laser beam; and the particles comprise smoke particles.

3. The method as claimed in claim 2 , wherein the data to be communicated comprises one or more of:

Camera/Laser synchronization information;

Camera/Laser timing information;

Camera/Laser System Configuration Data;

Laser intensity, duty cycle and camera exposure commands;

Laser & camera alignment data;

Laser enable/disable commands for a multi-laser system;

Laser marker activation/de-activation/duty cycle/intensity control commands;

Laser polarization or wavelength switching commands;

Fire Alarm status for reporting to a fire panel or other external systems.

4. The method as claimed in claim 1 , wherein the data is communicated by optical transmission means, with or without radio transmission means.

5. The method as claimed in claim 1 , further comprising the step of: communicating the data with a fire alarm panel.

6. The method as claimed in claim 1 , further comprising the step of: communicating the data such that the data is frequency shifted away from interfering signal frequencies.

7. The method as claimed in claim 1 , wherein at least one additional radiation source is adapted to communicate data in combination with one or more of:

the beam of radiation and

a means of detecting the increase in scattered radiation intensity in images.

8. The method as claimed in claim 7 , wherein the at least one additional radiation sources comprises a LED.

9. The method as claimed in claim 7 , wherein the means of detecting the increase in scattered radiation intensity in images comprises at least one color sensitive device and the beam and or additional sources of radiation adapted to communicate data are each further adapted to emit radiation of one of three different wavelengths.

10. The method as claimed in claim 1 , further comprising the step of:

communicating the data in accordance with the following communication technique: amplitude modulating the beam with serial data.

11. The method as claimed in claim 10 , wherein one or more of the modulating and encoding techniques comprises one or more of:

exclusive OR'ing the data with a pseudo-random sequence to randomize the data;

data compressing the data;

Manchester encoding;

pulse position modulation;

pulse width modulation;

frequency shift keying;

phase shift keying;

amplitude shift keying;

spread spectrum techniques.

12. The method as claimed in claim 4 , wherein: the beam of radiation comprises a laser beam; the means of detecting the variation in images comprises one or more of a camera and computing means; the particles comprise smoke particles.

13. The method according to claim 1 , wherein the field of view of the camera comprises at least part of a path of a laser beam and the laser beam does not impact on the camera lens directly, and wherein the light source is within the field of view of the camera.

14. A system for detecting particles, comprising:

a light source for emitting a beam of radiation into a monitored region;

means for detecting an increase in scattered radiation intensity, from the beam of radiation, in images of the region captured by a camera, the increase in scattered radiation intensity in images of the region indicating the presence of the particles wherein the beam of radiation is adapted to communicate data; and

means for encoding data for modulating the beam, to communicate the data.

15. The system according to claim 14 , wherein the field of view of the camera comprises at least part of a path of a laser beam and the laser beam does not impact on the camera lens directly, and wherein the light source is within the field of view of the camera.

16. The system claimed in claim 14 wherein:

the means for emitting a beam of radiation is a laser and the beam of radiation comprises a laser beam; and

the means for detecting the increase in scattered radiation intensity in images comprises one or more of a camera and computing means; and

the particles comprise smoke particles.

17. The system as claimed in claim 14 which further includes at least one additional radiation source adapted to communicate data in combination with one or more of:

the beam of radiation; and

a means of detecting the increase in scattered radiation intensity in images.