Patent Application
20090200496
The present invention pertains to the field of illumination and more particularly to headlamps for vehicles and especially for military vehicles.
The MMPV (Medium Mine Protected Vehicle), as well as other military vehicles, currently use a headlamp system specified in MIL-DTL-14465E (12 Aug. 1998), attached hereto, called a vehicular composite light assembly, shown in
For each headlamp system (the right or left) according to the prior art, MIL-DTL-14465E calls for sealed-beam lamps conforming to MS18003-411, two-filament type, for high and low-beam operation, a clear lens per drawing 7962266, a filter lens for passing substantially only infrared illumination, conforming to 7962265, thus providing the first incandescent bulb lamp 16 and the second incandescent bulb lamp 17. The prior art headlamp system also includes an incandescent blackout marker light 15 serving as a “position marker” emitting white light through two Y-shaped openings in an otherwise opaque filter lens, and an incandescent blackout driving light 14, per an applicable drawing or military standard, covered by a hood 14a to conceal the light from over-flying aircraft. MIL-DTL-14465E also prescribes that electrical cable shall conform to MIL-C-13486 (stranded tinned copper conductor, rubber insulating core, inner glass braid, black neoprene jacket).
Incandescent bulbs are inefficient, and the illumination provided by such bulbs, in the visible and also in the infrared, is significantly less than what can be provided by more recently developed lighting technology. High intensity discharge (HID) and light emitting diode (LED) technology provide greater luminosity while consuming less power than standard incandescent lamps.
An HID lamp consumes less power than an incandescent lamp and has a luminous intensity even greater than a halogen lamp, approximately 200,000 cd (candela). HID lamps work by producing an electric arc through a gas, and in the case of automotive applications, typically xenon gas. The color temperature of an HID light is in the range of 5000 K, similar to daylight. The average lifespan of an HID bulb is 2000 hours, roughly 5 times longer than a standard incandescent lamp.
Incandescent bulbs are inefficient infrared (IR) light sources because the illumination provided by such bulbs is significantly less than what can be provided by light-emitting diode (LED) technology. One problem with LED sources, however, is that excessive heat generated by the LED chip inside the light housing must be effectively dissipated to avoid damaging the headlight components.
It would be advantageous to have a headlamp system using more recent lighting technology, but that is fully interchangeable with the existing headlamp, using the same wiring harness, control signals, and housing as the existing headlamp.
The invention provides a headlamp system that meets the requirements of MIL-DTL-14465E except that in place of the sealed-beam lamps and the clear lens and filter lens therefor, two high intensity discharge (HID) lights are included, one for high beam and one for low beam, and an infrared illuminator is included using an array of infrared (IR) light emitting diodes (LEDs) having a spectrum centered at either 880 nm or 940 nm, depending on the application. IR LEDs are used as a light source for the blackout driving and marker lights. The headlamp system provided by the invention uses the same housing as the headlamp system of MIL-DTL-14465E, and also the same electrical cables, so that both the mechanical and electrical interfaces are the same as for the current headlamp system.
The above and other objects, features and advantages of the invention will become apparent from a consideration of the subsequent detailed description presented in connection with accompanying drawings, in which:
The following is a list of reference labels used in the drawings to label components of different embodiments of the invention, and the names of the indicated components.
Referring now to
The HID lights 18a 18b differ principally in the reflector lens component. The high beam HID light has a reflector component that provides a more collimated beam. In an advantageous embodiment, the HID lights used in the headlamp system 12 have an average luminescence of 200,000 cd (candela), and a color temperature of 5000 K (similar to daylight).
Ballasts 18d 18e are affixed to the interior of the housing back component 12a at a plurality of supports 12d, and fit into a cut out or recessed area 12c carved out of the interior of the metal housing component 12a, allowing the ballasts 18d 18e to fit further back into the housing. A metal plate 18f, typically made of aluminum, is affixed over the ballasts 18d 18e and attached to the back housing component at the plurality of supports 12d. The plate 18f has two holes to accommodate electrical wiring from the HID lights 18a 18b. A main printed circuit board 18c is affixed to the center of the plate 18f and mechanically supports and electrically connects the lighting components 141518a 18b 18d 18e 19a 19b 19g to electrical contacts within a base 20. The back component 12a includes a centralized hole located beneath the ballasts and the main printed circuit board through which all wiring for the lighting components exit the housing and enter the base 20. The base 20 contains electrical contacts as well as a nut, serving as both a physical connector to connect the headlamp system 12 to a vehicle, as well as an electrical connector, electrically connecting the headlamp's lighting components to a vehicle's control panel 61 and a power supply 62.
Located below the HID lights 18a 18b in the housing front component 12b is an IR illuminator 19. Referring more specifically to
In other embodiments, such as the embodiment shown in
The IR LEDs 19a 19b 19g may have a spectrum substantially centered about one or another wavelength in the infrared. In a typical embodiment, the center wavelength is 880 nm, but higher wavelengths are also used, including 940 nm. The higher wavelength may have the disadvantage of producing less IR illumination per Watt of power consumed, but typically produces no visible light whatsoever, whereas IR LEDs at 880 nm may produce some (reddish) light at the far end of the visible spectrum. In case of using IR LEDs at 940 nm, a headlamp system according to the invention may use an array of more LEDs, even up to three times the number of LEDs shown in
Below the IR illuminator 19 is an LED blackout marker light 15.
The headlamp system 12 of the invention has the same form and fit, mounting location, and hardware as the prior art headlamp system 11, uses the prior art vehicle wiring harness, and is installable by field service technicians in place of the prior art headlamp system. The headlamp system 12 uses the vehicle's existing switch configuration and wiring harness, illustrated schematically as including the control panel 61 for switching on and off power from the typically 24 v power supply 62, to different ones of the IR and visible illuminators, and also to the blackout marker light 15 and the blackout driving light 14.
IR LEDs suitable for use in the embodiment of the invention shown in
The HID lights used in headlamp system according to the invention are a 35 watt Xenon System available from Ibis Tek, LLC of Butler, Pa., the high beam HID light using part number 9-00002213, and the low beam HID light using part number 9-00002214. Ballasts 18d 18e for these lights are also available from Ibis Tek, LLC using part number HID 24 v 9-00002216.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the scope of the present invention, and the appended claims are intended to cover such modifications and arrangements.
Reference is made to and priority claimed from U.S. provisional application Ser. No. 61/023,622, filed on Feb. 13, 2008.
| Number | Date | Country | |
|---|---|---|---|
| 61023622 | Feb 2008 | US |
