Recognition/anti-collision light for aircraft

• US 6,642,856 B2
• Filed: 08/21/2001
• Issued: 11/04/2003
• Est. Priority Date: 11/06/1998
• Status: Expired due to Term

• Current Assignee: Goodrich Lighting Systems, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Lighting Systems, Inc. (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Knight, Todd Christopher, Draves, Raymond Henry, DeMarco, Ralph Anthony, Patel, Anish Vikram, Kielbon, Timothy Scott, Stephens, Merle Keith
• Primary Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US09/933,935
• Publication Number:
  US 20020080023A1
• Time in Patent Office: 805 Days
• Field of Search: 340/931, 340/981, 340/458, 340/642, 340/641, 340/331, 340/332, 340/953, 340/933, 340/947, 315/130, 315/65, 315/93, 315/129, 315/133, 315/88, 315/149-151, 362/470, 362/240, 356/151, 356/213, 356/215, 356/224, 356/218, 250/214.R, 250/205, 250/227.31
• US Class Current: 340/981
• CPC Class Codes: B60Q 1/2611 Indicating devices mounted on the roof of the vehicle
• CPC Class Codes: B64D 47/06 for indicating aircraft presence
• CPC Class Codes: F21V 13/04 the elements being reflectors and refractors for vehicle rear lights F21S43/40
• CPC Class Codes: F21V 7/0058 adapted to cooperate with light sources of shapes different from point-like or linear, e.g. circular light sources
• CPC Class Codes: H05B 41/30 in which the lamp is fed by pulses, e.g. flash lamp
• CPC Class Codes: H05B 41/38 Controlling the intensity of light
• CPC Class Codes: H05B 41/46 Circuits providing for substitution in case of failure of the lamp

Abstract

A recognition light includes a reflector having an axis and first and second annular semi-parabolic reflective surfaces which have respective focal points axially spaced apart from one another, and first and second annular lamps respectively disposed at the focal points. A cover surrounds the reflector and lamps and includes a lens for focusing the light along a plane perpendicular to the axis of the reflector, the lens including first and second Fresnel lens portions each including a convex lens and a prism lens, the convex lenses being disposed adjacent one another and transaxially aligned with the first and second lamps, respectively. A light detector detects light emitted from at least one of the lamps, a monitor circuit provides a fail signal when a characteristic of the light output of at least one of the lamps does not satisfy a specified criteria, and a control circuit first activates the first lamp and then the second lamp in response to receipt of the fail signal of the monitor circuit.

Claims

1. A recognition light for an aircraft, comprising:

a flashtube;

a flash capacitor connect d to the flashtube;

a power regulator for changing the flash capacitor to a first voltage level prior to being discharged through the flashtube;

a light detector positioned to detect light emitted from the flashtube;

a monitor circuit connected to the light detector for measuring the intensity of the detected light, comparing the measured intensity with a reference value corresponding to a predetermined light intensity level, and outputting a signal when a specified relationship exists between the measured intensity and the reference value that indicates a need to increase the light intensity of the flashtube; and

a control circuit connected to the power regulator and monitor circuit which causes the power regulator, in response to said signal from the monitor circuit, to charge the flash capacitor to a second voltage level higher than said first voltage level prior to being discharged through the flashtube, whereby the flashtube initially operates at a first power level and then at a second higher power level.

2. A method for increasing the useful life of a recognition light of an aircraft, comprising:

flashing a flashtube by repeatedly charging a flash capacitor to a first voltage and discharging the capacitor through the flashtube;

monitoring the light output of the flashtube;

comparing the measured light output of the flashtube with a reference value corresponding to a predetermined light intensity value;

increasing the voltage to which the flash capacitor is charged to a second voltage higher than the first voltage when a specified relationship exists between the measured light output and the reference value that indicates a need to increase the light intensity of the flashtube, thereby to increase the intensity of the flashes emitted by the flashtube.

3. A method for increasing the useful life of a recognition light of an aircraft, comprising:

flashing a flashtube;

monitoring the light output of the flashtube;

comparing the measured light output of the flashtube with a reference value corresponding to a predetermined light intensity value;

increasing the power delivered to the flashtube when a specified relationship exists between the measured light output and the reference value indicates a need to increase the light intensity of the flashtube, thereby to increase the intensity of the flashes emitted by the flashtube; and

providing a second flashtube operative to flash at a rate different than that of the first flashtube.

4. The method of claim 3, further comprising operating the second flashtube in place of the first flashtube when the measured light output of the first flashtube falls below a specified level.

5. The method of claim 3, further comprising monitoring the light output of the second flashtube and, when the light output of the second flashtube falls below a specified level, causing the second flashtube to flash at a rate different than that which he first flashtube flashed.

6. A method for monitoring the useful life of an aircraft recognition light, comprising:

flashing a flashtube;

monitoring the light output of the flashtube with a light detector that converts the detected light output into an integrated output voltage corresponding to the light output of a plurality of flashes of the flashtube;

providing an intensity comparator for comparing the integrated output voltage to a comparator reference voltage;

comparing the integrated output voltage to the comparator reference voltage and, if the integrated output voltage is less than the comparator reference voltage, transmitting a NOGO condition signal, and, if the integrated output voltage is greater than the comparator reference voltage, transmitting a GO condition signal;

storing the condition signal in an intensity status latch;

providing an intensity integrator fail counter for monitoring the GO/NOGO condition signal of the intensity status latch for a predetermined number of consecutive decreases and transmitting a boost signal or fail signal in response thereto;

monitoring the GO/NOGO condition signal and, if the predetermined number of consecutive NOGO measurements is attained, transmitting a boost signal for initiating an increase in power corresponding to an increase in the light output of the first flashtube; and

providing a second flash tube operative to flash at a rate different than that of the first flashtube, and continuing monitoring the GO/NOGO condition signal of the intensity status latch and, if the predetermined number of NOGO measurements is attained, transmitting a fail signal for initiating operation of the second flashtube at a rate substantially similar to the rate of the first flashtube.

7. The method of claim 6, further comprising using the intensity integrator fail counter for monitoring a GO/NOGO condition signal associated with the second flashtube and, if the predetermined number of NOGO measurements is attained, transmitting a boost signal for initiating an increase in power corresponding to an increase in the light output of the second flashtube.

8. The method of claim 7, further comprising continuing monitoring the GO/NOGO condition signal associated with the second flashtube and, if the predetermined number of NOGO measurements is attained, transmitting a fail signal for causing the second flashtube to flash at the different rate.

9. A recognition light for an aircraft, comprising first and second flashtubes;

and circuitry for operating either one of the first and second flashtubes at a first power level and later for operating at least one of the flashtubes at a second higher power level when the light intensity of said one of the flashtubes falls below a specified level, and wherein at least one of the first and second flashtubes is flashed at a first rate when operated at the first power level and at a second flash rate when operated at the second higher power level.