Warning light with tinted lens

• US 9,611,993 B2
• Filed: 05/19/2015
• Issued: 04/04/2017
• Est. Priority Date: 05/19/2014
• Status: Active Grant

• Current Assignee: Whelen Engineering Company Incorporated
• Original Assignee: Whelen Engineering Company Incorporated
• Inventors: Olson, Andrew J.
• Primary Examiner(s): Sember, Thomas M
• Application Number:
  US14/715,909
• Publication Number:
  US 20150330592A1
• Time in Patent Office: 686 Days
• CPC Class Codes: B60Q 1/2611 Indicating devices mounted on the roof of the vehicle
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21S 43/15 Strips of light sources
• CPC Class Codes: F21S 43/255 Filters
• CPC Class Codes: F21S 43/31 Optical layout thereof
• CPC Class Codes: F21S 43/40 characterised by the combination of reflectors and refractors
• CPC Class Codes: F21S 45/47 Passive cooling, e.g. using fins, thermal conductive elements or openings
• CPC Class Codes: F21S 45/49 Attachment of the cooling means
• CPC Class Codes: F21Y 2103/10 comprising a linear array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 5/20 Filters polarising elements G02B5/30
• CPC Class Codes: G02B 5/205 Neutral density filters

Abstract

A warning light includes a lens or cover is tinted with a grey or “smoke” tint that is not spectrally selective or alternatively referred to as “neutral density” in that it reduces transmission of all colors of light equally. The objective of the neutral tinted “smoked” lens is to reduce the conspicuity of warning lights when not in use. Ambient light penetration into the warning light is reduced by the proportion of tint and then light reflecting off the optical surfaces within the warning light are reduced again when passing through the tinted lens on the way out of the assembly. The resulting warning light appears dull and is less conspicuous than the same warning light or lightbar with a clear lens. The tinted lens or cover may include optical elements configured to re-direct light, and the entire lens or cover is molded from the same tinted plastic material.

Claims

1. An emergency warning light mountable to an emergency vehicle, said emergency warning light comprising:

a plurality of LED lamps each emitting light having a predetermined wavelength;

an optical structure arranged to re-direct at least a portion of light emitted from the plurality of LED lamps into a wide angle beam of light visible to an observer outside of the emergency vehicle; and

a lens disposed in a position where light from the LED light sources must pass through said lens to produce said emission pattern, said lens having an optical density of at least 0.071 that reduces or modifies the intensity of all wavelengths or colors of light equally, resulting in no substantial change in color of light emitted from the warning light relative to light generated by said plurality of LED lamps.

2. The emergency warning light of claim 1, wherein the optical density of said lens is between approximately 0.071 and 0.347.

3. The emergency warning light of claim 1, wherein said lens is the last material through which light from said LED lamps will pass in said emission direction before being emitted from said emergency warning light.

4. The emergency warning light of claim 3, wherein said optical structure includes at least one optical lens arranged to modify the direction of light emitted from said plurality of LED lamps before said light is incident upon said lens.

5. The emergency warning light of claim 1, wherein said warning light is a light bar mounted to the exterior of the emergency vehicle including a substantially rigid substrate, a plurality of light emitting subassemblies and said lens comprises a plurality of lens portions arranged to surround and enclose said plurality of light emitting subassemblies.

6. The emergency warning light of claim 1, wherein said wide angle beam of light is visible 360°

around the vehicle.