LED PAPI with condensation protection

• US 9,228,721 B2
• Filed: 06/12/2013
• Issued: 01/05/2016
• Est. Priority Date: 06/13/2012
• Status: Active Grant

• Current Assignee: ADB Safegate Americas LLC (ADB Safegate BVBA)
• Original Assignee: ADB Airfield Solutions LLC (ADB Safegate BVBA)
• Inventors: Hesch, John Jr., Ruffini, David L., Morrow, Glenn Alan, Schweder, Richard
• Primary Examiner(s): Le, Dinh
• Application Number:
  US13/916,340
• Publication Number:
  US 20130334984A1
• Time in Patent Office: 937 Days
• Field of Search: 362/135, 362/231, 362/276, 362/293, 315/152, 315/136
• US Class Current: 1/1
• CPC Class Codes: B64D 2203/00 Aircraft or airfield lights using LEDs
• CPC Class Codes: B64F 1/20 Arrangement of optical beacons
• CPC Class Codes: F21V 15/01 Housings, e.g. material or assembling of housing parts F21V15/02 takes precedence housings forming signs or letters G09F13/04
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/58 involving end of life detection of LEDs
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

In accordance with an example embodiment, there is disclosed herein a LED PAPI (10) with condensation protection. The condensation protection may suitably comprise passive components, such as gaskets and seals (26, 36) and a desiccant (48), and/or active components, such as a defroster (39) and/or a heater (50).

Claims

1. An apparatus (10), comprising:

a plurality of legs (14);

a chassis (12) mounted on the plurality of legs (14); and

a light assembly (22), the light assembly comprising a first surface at the first end of the light assembly (22) and a second surface at the second end of the light assembly(22), the light assembly (22) comprising;

a light source (28) disposed at the first end of the light assembly (22),

a first convex lens (32) disposed at the second end of the light assembly (22),

a second convex lens (30) disposed inside the light assembly (22) between the first convex lens (32) and the light source (28),

first seal (26) at the first end of the light assembly (22),

a second seal (36) at the second end of the light assembly (22),

a controller (60), and

a defroster (39);

wherein the controller (60) is operable to receive an first input (62) indicating a temperature of the first surface and a second input (64) indicating ambient air temperature; and

wherein the controller (60) operates the light source (28) and the defroster (39) based on the temperature of the first surface and the ambient air temperature.

2. The apparatus (10) set forth in claim 1, the second end of the light assembly further comprises:

a flange (44); and

a cover (38) that holds the second seal (36) against the flange (44).

3. The apparatus (10) set forth in claim 2, wherein the cover (38) is translucent.

4. The apparatus (10) set forth in claim 3, wherein the cover (38) is coated with Indium Tin Oxide.

5. The apparatus (10) set forth in claim 4, wherein a voltage is applied to the Indiun Tin Oxide coating to defrost the cover (38).

6. The apparatus (10) set forth in claim 1, wherein the light source (28) further comprises a heat sink (24).

7. The apparatus (10) set forth in claim 1, wherein the light source (28) comprises a light emitting diode array (52).

8. The apparatus (10) set forth in claim 7, wherein the light emitting diode array (52) comprises a plurality of groups (54, 65, 58L, 58R) having a plurality of light emitting diodes.

9. The apparatus (10) set forth in claim 8, wherein the controller is operative to, upon detecting a failure of a light belonging to a first group (54) of the plurality of groups, switch the light source (28) off.

10. The apparatus (10) set forth in claim 9, the controller (60) upon detecting a failure of a combination of at least one light emitting diode belonging to a second group of the plurality of groups and at least one light emitting diode belong to a third group of the plurality of groups is operable to switch the light source (28) off.

11. The apparatus (10) set forth in claim 1, wherein the controller (60) upon detecting power has been restored after a power failure, is operable to operate the defroster (39) for a predetermined time period before switching the light source on.

13. The apparatus (10) set forth in claim 1, the light assembly (22) further comprises a desiccant mounted in one of a group consisting of the first end and the second end.

12. The apparatus (10) set forth in 1 the controller (60) operates the defroster (39) is while the light source (28) is switched off to allow the light source to be switched on instantly.