Electric lamp and discharge devices: systems – Special application
Reexamination Certificate
2001-06-06
2003-07-08
Wong, Don (Department: 2821)
Electric lamp and discharge devices: systems
Special application
C315S291000, C315S316000
Reexamination Certificate
active
06590343
ABSTRACT:
BACKGROUND OF THE INVENTION
Light bars or emergency lights of the type used on emergency vehicles such as fire trucks, police cars, and ambulances, utilize warning signal lights to produce a variety of light signals. These light signals involve the use of various colors and patterns. In the past these warning signal lights have utilized incandescent and halogen light sources having reflective back support members and colored filters.
Many problems exist with the known methods for producing warning light signals. One particular problem with known light sources is their reliance on mechanical components to revolve or oscillate the lamps to produce the desired light signal. Additionally, these components increase the size of the light bar or emergency lights which may adversely affect the vehicles aerodynamic characteristics. Moreover, there is an increased likelihood that a breakdown of the light bar or light source will occur requiring the repair or replacement of the defective component. Finally, the known light bars and light sources require a relatively large amount of electrical current during operation. The demands upon the electrical power system for a vehicle may therefore exceed available electrical resources reducing optimization of performance.
In the past the most common light sources being used in light bars or emergency lights were halogen lamps or gaseous discharge xenon lamps. These lamps emanate large amounts of heat which is difficult to dissipate from a sealed light enclosure or emergency light and which may damage the electronic circuitry contained therein. In addition, these lamps consume large amounts of current requiring a large power supply or large battery or electrical source which may be especially problematic for use with a vehicle. These lamps also generate substantial electromagnetic emissions which may interfere with radio communications for a vehicle. Finally, these lamps, which are not rugged, have relatively short life cycles necessitating frequent replacement.
Another problem with the known warning signal lights is the use of filters to produce a desired color. Filtering techniques produce more heat that must be dissipated. Moreover, changing the color of a light source requires the physical removal of the filter from the light source or emergency light and the insertion of a new filter. Furthermore, filters fade or flake over time rendering the filters unable to consistently produce a desired color for observation in an emergency situation.
These problems associated with traditional signaling lamps are exacerbated by the fact that creating multiple light signals requires multiple signaling lamps. Further, there is little flexibility in modifying the light signal created by a lamp. For example, changing a stationary lamp into one that rotates or oscillates would require a substantial modification to the light bar which may not be physically or economically possible.
To attempt to solve the above identified and other problems Light Emitting Diodes (LED's) are being used to replace the gaseous discharge or incandescent lamps as used as automotive warning signal light sources.
LED's are particularly useful in the production of true light color output because LED's may be manufactured to provide a specific light wavelength at any desired frequency associated with a desired color. LED's are therefore capable of producing intense coloring associated with emergency vehicles, i.e., red, blue, amber, green, and clear or white.
Another problem with the known warning signal lights is the absence of flexibility for the provision of variable intensity for the light sources to increase the number of available distinct and independent visual light effects. In certain situations it may be desirable to provide a variable intensity for a light signal or a modulated intensity for a light signal to provide a unique light effect to facilitate observation by an individual. In addition, the provision of a variable or modulated intensity for a light signal may further enhance the ability to provide a unique desired light effect for observation by an individual.
No warning lights are known which are flexible and which utilize a variable light intensity to modify a standard lighting effect. The warning lights as known are generally limited to a flashing light signal. Alternatively, other warning signal lights may provide a sequential illumination of light sources. No warning or utility light signals are known which simultaneously provide for modulated and/or variable power intensity for a known type of light signal to create a unique and desirable type of lighting effect.
No warning signal lights are known which provide an irregular or random light intensity to a warning signal light to provide a desired lighting effect. Also, no warning light signals are known which provide a regular pattern of variable or modulated light intensity for a warning signal light to provide a desired type of lighting effect. Further, no warning light signals are known which combine a desired type of light effect with either irregular variable light intensity or regular modulated light intensity to provide a unique and desired combination lighting effect.
It has also not been known to provide alternative colored LED light sources which may be electrically controlled for the provision of any desired pattern of light signal such as flashing, pulsating, oscillating, modulating, variable, rotational, alternating, strobe, and/or combination light effects. In this regard, a need exists to provide a spatially and electrically efficient LED light source for use on an emergency or utility vehicle which provides the appearance of rotation or other types of light signals without the necessity of a mechanical devices. In addition, a need exists to provide a spatially and electrically efficient LED light source for use on an emergency vehicle which provides a flashing, modulated, variable, oscillating, rotational, alternating, and/or strobe light effects without the necessity of mechanical devices.
In view of the above, there is a need for a warning signal light that:
(1) Is capable of producing multiple light signals;
(2) Produces the appearance of a revolving or oscillating light signal without relying upon mechanical components;
(3) Generates little heat;
(4) Uses substantially less electrical current;
(5) Produces significantly reduced amounts of electromagnetic emissions;
(6) Is rugged and has a long life cycle;
(7) Produces a truer light output color without the use of filters;
(8) Is positionable at a variety of locations about an emergency vehicle; and
(9) Provides variable power intensity to the light source without adversely affecting the vehicle operator's ability to observe objects while seated within the interior of the vehicle.
In the past, flashing light signals emanating from light bars have been used to signal the presence of an emergency situation necessitating caution. A need exists to provide alternative colored LED light signals which may be electrically controlled for the provision of any desired pattern of light signal such as flashing, alternating, pulsating, oscillating, modulating, variable, rotational, and/or strobe light effects without the necessity of spatially inefficient and bulky mechanical devices. In that regard, a need exists to provide a spatially and electrically efficient LED light source for use on an emergency vehicle which provides any of the above-identified types of warning light signals without the necessity of mechanical devices.
Another problem encountered during use of LED light sources is the optimization of the efficiency of the LED light sources for the provision of maximized illumination. Insufficient electrical current provided to the LED's results in non-optimized illumination, and excess current may burn the LED's out, damage the driving circuitry, and/or reduce the operational life of the LED's. In the past manufacturing discrepancies have occurred between different lots of LED's where the different lots
911EP, Inc.
Vidas Arrett & Steinkraus
Vu Jimmy T.
Wong Don
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