Illumination – Supported by vehicle structure – Adjustable lamp or lamp support
Reexamination Certificate
2001-08-30
2003-04-15
O'Shea, Sandra (Department: 2875)
Illumination
Supported by vehicle structure
Adjustable lamp or lamp support
C362S037000, C362S281000, C362S427000
Reexamination Certificate
active
06547429
ABSTRACT:
FIELD OF INVENTION
The present invention relates generally to automotive lamps. More specifically, the present invention relates to bi-functional automotive headlamps.
BACKGROUND
Generally, conventional automotive forward lighting systems, or headlamp systems, are required to provide lighting to meet two (2) distinct functions. First, a headlamp system must provide illumination adequate for a normal driving condition in which a vehicle and its driver are likely to encounter other vehicles on the roadway, paricularly such vehicles traveling in the opposite direction on the same roadway in the form of oncoming traffic. Under this condition, an automotive forward lighting system must provide illumination that is sufficient to safely illuminate the area in front of the vehicle, but not be aimed in such a direction that the illumination distracts, or even temporarily blinds, the drivers of oncoming traffic. The illumination produced by a headlamp system to meet this first function or requirement is commonly referred to as “low beam.” Second, an automotive forward lighting system is required to provide additional illumination that can be utilized by a vehicle driver when additional lighting is necessary, but, for a variety of possible reasons, the concern over causing temporary discomfort to drivers of oncoming vehicles, is reduced or non-existent. The illumination typically provided under this function is generally directed slightly higher than that produced by a low beam, and generally more directly in front of the driver of the vehicle. The illumination produced by a headlamp system to meet this second function or requirement is commonly referred to as “high beam.”
Because a headlamp system's ability to provide adequate illumination, under both the low beam and high beam functions, is so critical to the safety of the occupants not only of that vehicle, but also of other vehicles on the roadway, numerous government laws and regulations dictate the exact requirements that an automotive forward lighting system must meet for both its low beam and high beam functions. Thus, automotive headlamp systems must be designed to meet such strict requirements for both the low beam lighting function as well as the high beam lighting function.
Several automotive forward lighting system configurations are well known in the industry. For example, a commonly used configuration utilizes four (4) total headlamps, with two (2) positioned on each side of the front end of the vehicle. Generally, with this type of configuration, one (1) headlamp on each side of the vehicle is used to accomplish the low beam function. The high beam function may then be accomplished by, in some designs, utilizing the remaining two (2) headlamps on either side of the vehicle to provide additional illumination, or supplement the light produced by the first two (2) headlamps. In this type of configuration, all four (4) headlamps are illuminated to accomplish the high beam function. Alternatively, the four (4) headlamp system configuration may simply utilize two (2) headlamps, again one (1) on each side of the vehicle, for the low beam function and the remaining two (2) headlamps for the high beam function. In this type of configuration, only two (2) headlamps are illuminated at any given time, but four (4) headlamps are necessary to meet the dual functions and requirements of low beam and high beam.
Unfortunately, the four (4) lamp design generally described above contains several disadvantages. For example, such designs are expensive to produce as they require more headlamp units per vehicle. Additionally, these systems are generally more expensive because the parts associated with such systems (e.g., housings, retainers, brackets, screws) are either more complicated than would otherwise be necessary, or simply more of such parts are required for the multi-lamp configuration. Performance of such a system can also be an issue. Specifically, in a four (4) lamp system with only two (2) headlamps illuminated for the low beam function and only the other two (2) headlamps illuminated for the high beam function, when switching from one beam pattern to the other (either low beam to high beam or high beam to low beam) in such a system, the illumination pattern may change dramatically in an instant. Such a dramatic change is undesirable as it may briefly confuse or disorient the vehicle's driver. Also, when multiple lamps are used to accomplish the low beam and high beam lighting requirements, respectively, a color difference can occur between the low beam light and the high beam light. Such a color difference is not aesthetically pleasing or desirable.
Additionally, a four (4) lamp system may present safety concerns as it is possible during cold weather conditions for icing to occur on the outer surface of a headlamp if that headlamp is not illuminated continuously. Thus, a switch to high beam during such conditions may not provide the necessary illumination as the high beam headlamps have malfunctioned due to ice formation. Furthermore, the four (4) lamp system generally requires more space which can be problematic on the front end of a vehicle where the space available for any one assembly is at a minimum. Thus, these four (4) lamp systems, which can be relatively large, tend to limit design options for a vehicle's front-end. Moreover, the overall appearance of the four (4) lamp system, which again is generally larger and contains more parts, is considered by some as undesirable, especially for vehicles in which a sleek, aerodynamic appearance is important. Finally, because multiple lamp systems utilize more lamps, usually four (4) compared to two (2), they generally require and consume more electrical energy.
In order to attempt to address the shortcomings of the four (4) headlamp system, two (2) headlamp systems have been developed and are well known in the art. These two (2) headlamp systems utilize only a single lamp on each side of the front end of a vehicle, with each of those lamps performing both the low beam and high beam lighting functions. For ease of reference, the term “bi-functional” is used herein to describe such a single automotive headlamp unit that is capable of producing both a low beam lighting pattern and a high beam lighting pattern. One example of a bi-functional system used in the past is a system that utilizes two (2) headlamps, each with two (2) light bulb filaments. The different filaments of each lamp are utilized independently to accomplish the low beam function and the high beam function, respectively. Thus, while having the appearance of only utilizing two (2) lamps, in essence, this type of forward lighting system still utilizes four (4) light sources. This type of system also has disadvantages. The specialized bulbs utilized for this type of system can be overly complex and expensive to both manufacture and replace. Additionally, replacement may be necessary if “burn-out” occurs for the bulb filament accomplishing one (1) lighting function, even though the filament for the other function is still in working condition.
Another attempt to accomplish bi-functionality for a two (2) lamp forward automotive lighting system that is known in the industry involves lamps that allow the light source to be repositioned relative to the lamp reflector. Generally, in order to accomplish high beam functionality the light source, or light bulb, is repositioned relative to the headlamp reflector thus changing the direction of the emitted light. While bi-functionality is accomplished by this system, it is necessary to closely control the critical tolerances involved with repositioning the light source. Such control can be difficult and expensive to accomplish initially, and may be even more difficult to control over the life of the vehicle. Subtle changes in the positioning of the light source can result in undesirable shifts in the vehicle lighting pattern for either the low beam or high beam, or even both. Thus, the reliability of such a system is suspect. Furthermore, adjusting the “aim” of such an
Collins Tony E.
Vanduyn Paul D.
Forman Alex D.
Guide Corporation
Ice Miller
O'Shea Sandra
Ster Brian T.
LandOfFree
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