EP0200289A1 — Safety system for laser-utilising facilities

Claim 1

Independent Claim 64 words

A safety system for a laser-utilising facility, comprising an enclosure housing said facility, sensor means for monitoring the radiation emitted by at least one surface or wall forming, or located within, said enclosure and means responsive to the sensor means for modifying operation of the laser in response to levels of emitted radiation, or changes thereof, in excess of a threshold value or values.

Claim 2

Dependent Claim 64 words

A safety system for a laser-utilising facility, comprising an enclosure housing said facility, sensor means for monitoring the radiation emitted by at least one surface or wall forming, or located within, said enclosure and means responsive to the sensor means for modifying operation of the laser in response to levels of emitted radiation, or changes thereof, in excess of a threshold value or values.

Claim 3

Dependent Claim 36 words

A system as claimed in Claim 1 in which said sensor means forms part of scanning means providing the sensor means with an overall field of view which encompasses the surface(s) or wall(s) to be monitored.

Claim 4

Dependent Claim 71 words

A system as claimed in Claim 2 including at least one reference source of radiation serving as a hot spot located at a predetermined position relative to the enclosure, said scanning means being operable to include said reference source(s) in the overall field of scanning seen by said sensor means and said modifying means being arranged to modify laser operation only in response to radiation sources other than said reference source(s).

Claim 5

Dependent Claim 27 words

A system as claimed in Claim 3 including means for selectively or periodically testing response of said sensor means and/or laser-operation modifying means to the reference source(s).

Claim 6

Independent Claim 43 words

A system as claimed in any one of Claims 2-4 in which said scanning means is arranged to provide an instantaneous field of view which is extended in a direction generally orthogonal to the direction in which the field of view is scanned.

Claim 7

Independent Claim 23 words

A system as claimed in any one of Claims 2-5 in which said scanning means is selectively operable to scan at different speeds.

Claim 8

Independent Claim 43 words

A system as claimed in any one of Claims 2-5 in which separate sensor means and associated scanning means are located at different points relative to the enclosure, and said separate scanning means are operable at different scanning speeds with respect one another.

Claim 9

Independent Claim 57 words

A system as claimed in any one of Claims 2-7 in which signal processing means is provided for deriving from said sensor means a series of output signals corresponding to successive instantaneous fields of view, said signal processing means being arranged to analyse said output signals both individually and groupwise to provide different degrees of temperature resolution.

Claim 10

Independent Claim 95 words

A system as claimed in any one of Claims 2-8 in which said scanning means is operable to scan the area under surveillance cyclically to provide the sensor means repeatedly with the same overall field of view and further including means for storing a reference radiation profile for the overall field of view produced by the cyclic scan and means for comparing the outputs produced by said sensor means during each scan cycle with the stored reference profile whereby localised changes in the level of radiation emission within said field of view can be detected.

Claim 11

Dependent Claim 89 words

A system is claimed in Claim 9 including means for repeatedly sampling the output of the sensor means in the course of each scanning cycle to produce a predetermined number of signal samples corresponding to successive instantaneous fields of view within the overall field, said store means storing a number of reference signal samples each corresponding to a respective one of said successive instantaneous fields of view and said comparing means being operable to compare each sampled output signal from the sensor means with the corresponding stored reference signal.

Claim 12

Dependent Claim 49 words

A system as claimed in Claim 10 including threshold store means for storing at least one threshold value, said comparing means being operable to determine whether or not the difference between each sampled output signal and the associated stored reference signal exceeds the threshold or a respective threshold value.

Claim 13

Independent Claim 63 words

A system as claimed in Claims 9, 10 or 11 in which the stored reference profile is periodically updated using the profile obtained in the course of a scanning cycle, said updating being effected after each set of N scanning cycles, where N is an integer greater than or equal to 1, by substituting the stored reference signals by respective sampled output signals.

Claim 14

Dependent Claim 105 words

Apparatus for monitoring infra-red emissions comprising sensor means responsive to infra-red radiation for producing an electrical output related to the intensity of infra-red radiation incident thereon, scanning means for effecting a cyclical scan to provide the sensor means, in use of the apparatus, repeatedly with an overall field of view encompassing an area under surveillance, means for analysing the outputs of the sensor means with reference to a predetermined threshold value or values to detect within said overall field of view arising sources of infra-red radiation representing potentially hazardous conditions, and means for generating an actuating signal in the event of detection of such sources.

Claim 15

Dependent Claim 105 words

Apparatus for monitoring infra-red emissions comprising sensor means responsive to infra-red radiation for producing an electrical output related to the intensity of infra-red radiation incident thereon, scanning means for effecting a cyclical scan to provide the sensor means, in use of the apparatus, repeatedly with an overall field of view encompassing an area under surveillance, means for analysing the outputs of the sensor means with reference to a predetermined threshold value or values to detect within said overall field of view arising sources of infra-red radiation representing potentially hazardous conditions, and means for generating an actuating signal in the event of detection of such sources.

Claim 16

Dependent Claim 65 words

Apparatus as claimed in Claim 13 including means for testing said sensor means, said testing means being operable to suppress said actuating signal only in response to detection of a source(s) by said analysing means within a predetermined zone or zones of the scanned .field of view whereby said actuating signal is generated only in response to potentially hazardous sources lying outside said predetermined zone(s).

Claim 17

Dependent Claim 36 words

Apparatus as claimed in Claim 14 in which said scanning means is arranged to provide an instantaneous field of view which is extended in a direction generally orthogonal to the direction in which scanning is effected.

Claim 18

Dependent Claim 23 words

Apparatus as claimed in any one of Claims 13-15 in which the scanning means is operable selectively to effect scanning at different speeds.

Claim 19

Dependent Claim 53 words

Apparatus as claimed in any one of Claims 13-16 in which said analysing means is arranged to derive from the sensor means a series of output signals corresponding to successive instantaneous fields of view and is operable to analyse said output signals both individually and groupwise to provide different degrees of temperature resolution.

Claim 20

Dependent Claim 112 words

Apparatus as claimed in any one of Claims 13-17 in which said analysing means includes means for repeatedly sampling the output of the sensor means in the course of each scanning cycle to produce a predetermined number of sampled signals each corresponding to successive instantaneous fields of view, store means storing a number of reference signals each corresponding to a respective one of said successive instantaneous fields of view and collectively forming a reference radiation profile for the overall field of view, and means for comparing each sampled signal with the associated stored reference signal to determine whether or not the difference therebetween exceeds the threshold value or a respective threshold value.

Claim 21

Independent Claim 124 words

A system or apparatus as claimed in any one of Claims 2-18 in which the scanning means comprises a support, a scanning head mounted on the support for -rotation about a predetermined axis, drive means for effecting continuous rotation of the scanning head about said predetermined axis, an infra-red sensor located on said axis to intercept infra-red radiation travelling in the direction of said axis, an anamorphic lense carried byt he scanning head and arranged so that its wide angle of view extends in a plane which contains or is parallel to said predetermined axis of rotation, and beam focussing and deflecting optical components for effecting focussing.of the infra-red radiation refracted radially inwardly from said lens and deflecting the same along said predetermined axis.

Claim 22

Dependent Claim 42 words

A system as claimed in Claim 19 in which said optical components comprise a beam-folding mirror for deflecting the radially inwardly refracted radiation from said anamorphic lens along said predetermined axis and a focussing lens interposed between the mirror and the sensor.

Safety system for laser-utilising facilities

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag