US4620104A — Infrared radiation source arrangement

Claim 1

Independent Claim 162 words

An improvement infrared radiation source arrangement for use in producing at least one pulsating beam of infrared radiation having an electrically insulating substrate, at least one resistive element comprising an electrically conducting film carried on one surface of said substrate, and electrical circuit means for energising and controlling the emission of infrared radiation from said at least one resistive element; in which the improvement comprises that said electrical circuit means is arranged to energise said at least one resistive element with pulsating current whereby pulsating thermal infrared radiation is emitted, and that the thickness (L) of the substrate, and the thermal conductivity (k), specific heat capacity (C) and density (ρ) of the substrate material are so chosen that the time constant τ s of the substrate, where ##EQU6## approximately satisfies the relationship τ s being less than or approximately equal to f -1 where f is the highest pulsation frequency contained in the energising current as provided by the electrical circuit means.

Claim 2

Dependent Claim 162 words

An improvement infrared radiation source arrangement for use in producing at least one pulsating beam of infrared radiation having an electrically insulating substrate, at least one resistive element comprising an electrically conducting film carried on one surface of said substrate, and electrical circuit means for energising and controlling the emission of infrared radiation from said at least one resistive element; in which the improvement comprises that said electrical circuit means is arranged to energise said at least one resistive element with pulsating current whereby pulsating thermal infrared radiation is emitted, and that the thickness (L) of the substrate, and the thermal conductivity (k), specific heat capacity (C) and density (ρ) of the substrate material are so chosen that the time constant τ s of the substrate, where ##EQU6## approximately satisfies the relationship τ s being less than or approximately equal to f -1 where f is the highest pulsation frequency contained in the energising current as provided by the electrical circuit means.

Claim 3

Dependent Claim 151 words

An improved infrared radiation source arrangement for use in producing at least one pulsed beam of infrared radiation, having an electrical insulating substrate, at least one resistive element comprising an electrically conducting film carried on one surface of said substrate, and electrical circuit means for energising and controlling the emission of infrared radiation from said at least one resistive element; in which the improvement comprises that said electrical circuit means is arranged to energise said at least one resistive element with pulses whereby pulses of thermal infrared radiation are emitted, and that the thickness (L) of the substrate is so chosen in relation to the thermal conductivity (k), specific heat capacity (C) and density (ρ) of the substrate material, that the following relationship is satisfied: ##EQU7## where τ 1 is the pulse length of the pulses provided by said electrical circuit means, and τ 2 is the spacing between said pulses.

Claim 4

Dependent Claim 151 words

An improved infrared radiation source arrangement for use in producing at least one pulsed beam of infrared radiation, having an electrical insulating substrate, at least one resistive element comprising an electrically conducting film carried on one surface of said substrate, and electrical circuit means for energising and controlling the emission of infrared radiation from said at least one resistive element; in which the improvement comprises that said electrical circuit means is arranged to energise said at least one resistive element with pulses whereby pulses of thermal infrared radiation are emitted, and that the thickness (L) of the substrate is so chosen in relation to the thermal conductivity (k), specific heat capacity (C) and density (ρ) of the substrate material, that the following relationship is satisfied: ##EQU7## where τ 1 is the pulse length of the pulses provided by said electrical circuit means, and τ 2 is the spacing between said pulses.

Claim 5

Dependent Claim 31 words

An arrangement according to claim 1 in which a back plate of good heat conducting properties is provided on the opposite surface of the substrate and in good thermal contact therewith.

Claim 6

Dependent Claim 63 words

An arrangement according to claim 1 in which each film is made to have a particularly high or, respectively, particularly low emission of infrared radiation in specially selected spectral intervals, the film being composed of an electrically conducting sub-layer of low emissivity, onto which there has been deposited a material that, upon heating, emits infrared radiation with a pronounced and characteristic spectral structure.

Claim 7

Dependent Claim 24 words

An arrangement according to claim 1 in which the substrate is adapted to serve also as the circuit board for the electrical circuit means.

Claim 8

Dependent Claim 32 words

An arrangement according to claim 1 in which a said film is made from a material whose resistivity is strongly temperature dependent and the film itself functions as a temperature sensing element.

Claim 9

Dependent Claim 53 words

An arrangement according to claim 1 in which the electrical circuit means comprises a reference detector to measure radiation from the films, the reference detector being incorporated into the circuit to influence the energising circuit so that the radiation intensity from each film, as measured at the reference dectector, can be individually controlled.

Claim 10

Dependent Claim 57 words

An arrangement according to claim 1 in which at least two films are so arranged as to form an array of radiators, each film being adapted to be separately driven by an electric current that is controlled in time in such a way that the radiation pulsations from the separate films can be distinguished from one another.

Claim 11

Dependent Claim 22 words

An arrangement according to claim 8, in which said at least two films are respectively driven at different pulse rates or frequencies.

Claim 12

Dependent Claim 30 words

An arrangement according to claim 8, in which said at least two films are all driven at the same pulse rate or frequency, but mutually displaced in time or phase.

Claim 13

Dependent Claim 21 words

An arrangement according to claim 8, in which said at least two films are situated on one and the same substrate.

Claim 14

Dependent Claim 38 words

An arrangement according to claim 8, including a dispersive optical element for causing beams of radiation from different films within an array of radiators to be fully or partially superimposed, and to be directed into a common direction.

Claim 15

Dependent Claim 46 words

An arrangement according to claim 8, in which each film is provided wiht an optical filter, the transmission characteristics of the optical filters being mutually different, whereby the films with their associated filters are adapted to provide infrared radiation each chiefly within its own spectral range.

Claim 16

Dependent Claim 24 words

An arrangement according to claim 13, in which the films and the optical filters are placed on opposite sides of an optically transparent substrate.

Claim 17

Dependent Claim 31 words

An arrangement according to claim 2 in which a back plate of good heat conducting properties is provided on the opposite surface of the substrate and in good thermal contact therewith.

Claim 18

Dependent Claim 63 words

An arrangement according to claim 2 in which each film is made to have a particularly high or, respectively, particularly low emission of infrared radiation in specially selected spectral intervals, the film being composed of an electrically conducting sub-layer of low emissivity, onto which there has been deposited a material that, upon heating, emits infrared radiation with a pronounced and characteristic spectral structure.

Claim 19

Dependent Claim 24 words

An arrangement according to claim 2 in which the substrate is adatped to serve also as the circuit board for the electrical circuit means.

Claim 20

Dependent Claim 32 words

An arrangement according to claim 2 in which a said film is made from a material whose resistivity is strongly temperature dependent and the film itself functions as a temperature sensing element.

Claim 21

Dependent Claim 53 words

An arrangement according to claim 2 in which the electrical circuit means comprises a reference detector to measure radiation from the films, the reference detector being incorporated into the circuit to influence the energising circuit so that the radiation intensity from each film, as measured at the reference detector, can be individually controlled.

Claim 22

Dependent Claim 57 words

An arrangement according to claim 2 in which at least two films are so arranged as to form an array of radiators, each film being adapted to be separately driven by an electric current that is controlled in time in such a way that the radiation pulsation from the separate films can be distinguished from one another.

Claim 23

Dependent Claim 22 words

An arrangement according to claim 20, in which said at least two films are respectively driven at different pulse rates or frequencies.

Claim 24

Dependent Claim 30 words

An arrangement according to claim 20, in which said at least two films are all driven at the same pulse rate or frequency, but mutually displaced in time or phase.

Claim 25

Dependent Claim 21 words

An arrangement according to claim 20, in which said at least two films are situated on one and the same substrate.

Claim 26

Dependent Claim 38 words

An arrangement according to claim 20, including a dispersive optical element for causing beams of radiation from differenct films within an array of radiators to be fully or partially superimposed, and to be directed into a common direction.

Claim 27

Dependent Claim 46 words

An arrangement according to claim 20, in which each film is provided with an optical filter, the transmission characteristics of the optical filters being mutually different, whereby the films with their associated filters are adapted to provide infrared radiation each chiefly within its own spectral range.

Claim 28

Dependent Claim 24 words

An arrangement according to claim 25, in which the films and the optical filters are placed on opposite sides of an optically transparent substrate.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-10-27	1990-04-28	1990-10-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-10-27	1994-04-28	1994-10-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-10-27	1998-04-28	1998-10-28	$7700.00	Window Closed / Lapsed

Infrared radiation source arrangement

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