Recognition/anti-collision light for aircraft

• US 20040075575A1
• Filed: 09/02/2003
• Published: 04/22/2004
• Est. Priority Date: 11/06/1998
• Status: Active Grant

• Current Assignee: Anish Vikram Patel, Merle Keith Stephens, Ralph Anthony Demarco, Raymond Henry Draves, Timothy Scott Kielbon, Todd Christopher Knight
• Original Assignee: Anish Vikram Patel, Merle Keith Stephens, Ralph Anthony Demarco, Raymond Henry Draves, Timothy Scott Kielbon, Todd Christopher Knight
• Inventors: Knight, Todd Christopher, Draves, Raymond Henry, DeMarco, Ralph Anthony, Patel, Anish Vikram, Kielbon, Timothy Scott, Stephens, Merle Keith
• Granted Patent: US 6,989,768 B2
• Time in Patent Office: Days
• US Class Current: 340/815.4
• 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 comprising:

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.

2. The recognition light of claim 1, comprising a control circuit for sequentially operating the first and second annular lamps.

3. The recognition light of claim 1, comprising a cover surrounding the reflector and lamps, the cover including a lens for focusing the light along a plane perpendicular to the axis of the reflector.

4. The recognition light of claim 1, the lens having 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.

5. The recognition light of claim 1, wherein the semi-parabolic reflective surface comprises a half-parabolic reflective surface.

6. A recognition light comprising:

a parabolic reflector;

first and second annular lamps surrounding the reflector; and

a cover surrounding the reflector and lamps, the cover including 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.

7. A recognition light comprising:

first and second lamps;

a light detector positioned to detect light emitted from at least one of the lamps;

a monitor circuit connected to the light detector for providing 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 connected to the monitor circuit and the first and second lamps for first activating the first lamp and then the second lamp in response to receipt of the fail signal of the monitor circuit.

8. The recognition light of claim 7, wherein the second lamp is operative to flash at a different rate than the first lamp.

9. The recognition light of claim 7, further including a spool-shaped reflector, the first and second lamps being circumferentially disposed around the narrow portion of the spool-shaped reflector, the spool-shaped reflector being operative to reflect light emitted by either of the first or second lamps.

10. The recognition light of claim 9, wherein the first and second lamps are substantially circular in shape and have common centers.

11. The recognition light of claim 9 or 10, wherein the first lamp is spaced from the second lamp by one or more spacers.

12. The recognition light of claim 11, wherein the one or more spacers comprise cantilevered spacer bars projecting outwardly from the narrow portion of the spool-shaped reflector.

13. The recognition light of claim 12, wherein the spool-shaped reflector is formed from first and second axially aligned half portions, the first half portion comprising an upper rim of the spool-shaped reflector, the second half portion comprising a lower rim of the spool-shaped reflector.

14. The recognition light of claim 8, wherein the spool-shaped reflector is formed from first and second axially aligned half portions, the first half portion comprising an upper rim of the spool-shaped reflector, the second half portion comprising a lower rim of the spool-shaped reflector.

15. The recognition light of claim 14, wherein the half portions form in cross-section a substantially arc-shaped reflective surface operative to reflect light emitted by the first or second lamp substantially radially outwardly from the axis of the spool-shaped reflector.

16. The recognition light of claim 15, wherein the half portions define a reflective surface at least partially parabolic in shape.

17. The recognition light of claim 16, wherein the first and second lamps are disposed at the focal points of the partially parabolic shaped portions.

18. The recognition light of claim 17, wherein the partially parabolic shaped portions are greater in size than that of a half parabola.

19. The recognition light of claim 7, wherein the electrical control circuitry includes a voltage doubler for triggering the first and second lamps.

20. The recognition light of claim 19, wherein the voltage doubler comprises a series trigger transformer comprising a first trigger coil and a second trigger coil, and wherein the second trigger coil is serially connected to the cathode input of the lamps via respective flash capacitors.

21. The recognition light of claim 20, wherein when a trigger pulse is applied to the first trigger coil, at or within a predetermined time thereafter the cathode of the first or second lamp is subjected to a negative voltage pulse, thereby causing the first or second lamp to flash.

22. A recognition light for an aircraft, comprising:

a 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 and comparing the measured intensity with a reference value corresponding to a predetermined light intensity level; and

a control circuit connected to the flashtube and monitor circuit for flashing the flashtube at a first power level and then at an increased power level when the measured intensity drops below the reference value, thereby to increase the intensity of the flashes emitted by the flashtube to above the predetermined light intensity level.

23. 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 the measured light output drops below the reference value, thereby to increase the intensity of the flashes emitted by the flashtube to above the reference value.

24. The method of claim 23, further comprising providing a second flashtube operative to flash at a rate different than that of the first flashtube.

25. The method of claim 24, further comprising triggering the second flashtube before the measured light output of the first flashtube falls below the reference value.

26. The method of claim 24, further comprising monitoring the light output of the second flashtube and, when the light output of the second flashtube approaches the reference value, triggering the second flashtube to flash at a rate different than that which the first flashtube flashed.

27. 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.

28. The method of claim 27, further comprising providing an intensity comparator for comparing the integrated output voltage to a comparator reference voltage.

29. The method of claim 28, further comprising 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.

30. The method of claim 29, further comprising storing the condition signal in an intensity status latch.

31. The method of claim 30, further comprising temporarily inhibiting the intensity status latch from providing a NOGO condition signal for a predetermined amount of time or until the first flashtube is sufficiently warmed up to provide accurate measurements.

32. The method of claim 30, further comprising 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.

33. The method of claim 32, further comprising 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.

34. The method of claim 33, further comprising providing a second-flashtube 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-operating the second flashtube at a rate substantially similar to the rate of the first flashtube.

35. The method of claim 34, further comprising using the intensity integrator fail counter for monitoring the 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.

36. The method of claim 35, 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 triggering the second flashtube to flash at the different rate.

37. A method for increasing the useful life of a recognition light, comprising:

providing first and second lamps;

operating the first lamp;

monitoring a characteristic of the light output of the first lamp and providing a fail signal when the characteristic of the light output of the first lamp does not satisfy a specified criteria; and

stopping operation of the first lamp and operating the second lamp in response to receipt of the fail signal.

38. A method for providing visual notification of required replacement of an anti-collision light prior to failure of the anti-collision light, comprising:

providing an anti-collision light including a lamp;

operating the lamp at a first flash rate at a light intensity above a predetermined light intensity value; and

operating the lamp at a second flash rate distinguishable from the first rate when the light intensity of the lamp approaches the predetermined light intensity value.

39. A lamp fixture comprising an annular reflector and first and second annular lamps surrounding the reflector, and the reflector having a reflector surface configured to reflect light outwardly from the lamp fixture from both of the lamps.