This patent application claims the benefit of Czech Republic Patent Application No. PV 2005-435 filed Jul. 4, 2005.
The present invention relates generally to lighting systems for a motor vehicle, and more particularly relates to a lighting system which adapts to driving conditions.
For many years automobile manufacturers have been striving to improve roadway illumination by various vehicle lighting configurations. For example, many modern vehicles include daytime running lights where the vehicle's headlights are illuminated constantly during daylight to make the vehicles more noticeable. Many vehicles also include lighting systems which detect low light levels and energize the headlamps. As another example, U.S. Pat. No. 6,761,476, commonly owned by the assignee of the present application, the disclosure of which is hereby incorporated by reference in its entirety, discloses a multi-axis swivel mechanism which permits the headlights mounted thereto to be directed based on the vehicle direction.
Despite these and other improvements to lighting systems for motor vehicles, there remains a need to provide a lighting system which is increasingly adaptable to driving conditions such as vehicle speed and weather conditions on the roadway.
The present invention provides a lighting system for a motor vehicle that is sufficiently robust to adapt to vehicle speed and weather conditions. In one embodiment constructed in accordance with the teachings of the present invention, the lighting system generally includes a left light assembly and a right light assembly. Each light assembly has a primary light unit and a secondary light unit. The primary light units produce a beam pattern including a high beam and a low beam, while the secondary light units produce a beam pattern including at least a low beam. A controller is operatively connected to the left and right light assemblies for controlling the operation of the primary and secondary light units, and also receives information on vehicle speed. The controller operates only the primary light units when the vehicle speed is below a predetermined value. The controller operates both the primary and secondary light units when the vehicle speed is above the predetermined speed value.
According to more detailed aspects, the predetermined speed value is preferably in the range of about 40 kmph to 100 kmph (about 25 mph to 62 mph). The beam pattern of the primary light units circumscribes the beam pattern of the secondary light units, resulting in a reduced side spread at higher speeds. The left and right assemblies may further include a tertiary light unit, the tertiary light unit producing a beam pattern including a low beam beamed substantially to the left and right, respectively, of the vertical axis. The controller receives information on a direction of the vehicle, and operates the tertiary light unit of the left light assembly when the vehicle turns left and operates the tertiary light unit of the right light assembly when the vehicle turns right. The tertiary light units may also be operated only when the vehicle speed is below the predetermined value. The controller may further receive information on weather affecting the vehicle and operate only the secondary and tertiary light units when there are wet conditions, and operate only the primary light units in the tertiary light units when there are fog conditions. The primary light units may be pivotally mounted, and the controller may rotate the primary light units to the left when the vehicle turns left and rotate the primary light units to the right when the vehicle turns right.
In another embodiment constructed in accordance with the teachings of the present invention, the lighting system generally includes a left light assembly and a right light assembly. The left and right light assemblies each have a primary light unit and a secondary light unit. The primary light units produce a beam pattern including a high beam and a low beam, while the secondary light units produce a beam pattern including a low beam. The beam pattern of the secondary light units has a lower vertical cut-off above a lower edge of the beam pattern of the primary light units.
According to more detailed aspects of this embodiment, the lower vertical cut-off is linear and about 5 to 10 degrees below the vertical axis. The vertical beam spread of the secondary light units is preferably less than a vertical beam spread of the primary light units. Likewise, the horizontal beam spread of the secondary light units is preferably less than a horizontal beam spread of the primary light units. Most preferably, the horizontal beam spread of the secondary light units is about 34 to 62 degrees, while the horizontal beam spread of the primary light units is about 50 to 90 degrees. The beam pattern of the primary light units may be centered on the horizontal and vertical axes, while the beam pattern on the secondary light units is centered on the horizontal axis. A tertiary light unit may be further employed in the left and right light assemblies, and include a low beam substantially to the left and right of the vertical axis. Most preferably, the beam pattern of each tertiary light unit extends horizontally to a point at least 60 degrees from the vertical axis. Thus, the beam pattern of the tertiary light units have a horizontal spread greater than the horizontal spread of the beam pattern of the primary light units.
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
Turning now to the figures,
The primary light units 26 are preferably of the projector type, and preferably include both a high beam and a low beam, such as the HID unit disclosed in U.S. Pat. No. 6,186,651, the disclosure of which is hereby incorporated by reference in its entirety. Furthermore, the primary light units are preferably mounted for rotation (as will be discussed in more detail below), exemplary light units being disclosed in U.S. Pat. No. 6,761,476 and EP 1052446, the disclosures of which are also hereby incorporated by reference in their entirety. As used herein high beam refers to a beam pattern having light above a horizontal axis, and low beam means a beam pattern having a majority of light below the horizontal axis. It will be recognized that virtually any type of head lamp may be used as the primary light unit 26 so long as a high beam and a low beam are provided. As is well known in the art, high and low beams may be produced through multiple light sources (i.e. multiple filaments) and/or through the use of shields and reflectors which may be operated to cut-off a portion of the light to provide high and low beams. The secondary light units 28 also produce a beam pattern including a high beam and a low beam, although the present invention may be readily employed through the use of secondary light units 28 which only have a low beam.
The tertiary light units 30 provide at least a low beam directed to the side, as will be described in more detail below. The lighting system 20 also preferably includes a controller 32 regulating the operation of the left and right light assemblies 22, 24, and in particular controlling the energization of the individual primary, secondary and tertiary light units 26, 28, 30. The controller 32, which may comprise any type of controller such as a central processing unit or other processor, circuit, or chip, determines the operation of the light units 26, 28, 30 based on a variety of variables including vehicle speed 34, road conditions or weather 35, vehicle direction 36, and various user input 38 such as a manual control for switching between high and low beam. As will be recognized by those skilled in the art, information on vehicle speed 34 may be provided to the controller 32 in a variety of manners, such as being provided by other control systems of the vehicle, or directly from sensors such as wheel speed sensors, accelerometers, engine or transmission sensors, fuel throttle sensors or even external positioning systems such as GPS. Similarly, information on weather or road conditions 35 may be provided to the controller 32 in a variety of well known manners, such as through the use of satellite or radio broadcast, user input, vehicle sensors, optical sensors (i.e. rain sensors), the on/off condition of windshield wipers, or through user input. Still further, information on vehicle direction 36 may be provided to controller 32 in a variety of well known ways, such as through direct sensing of the wheels, the steering mechanism, or the steering wheel, through the use of GPS, or using other sensors such as lateral acceleration sensors or other vehicle dynamics sensors which may be employed to determine when the vehicle is turning or otherwise heading in a straight direction. User input 38 is provided to the controller 32, generally to manually control operation of the lighting system 20 and indicate when a high beam mode is desired or a low beam mode, but may also include user inputs of vehicle speed 34, weather or road conditions 35, or vehicle direction 36.
The beam patterns of the light units 26, 28, 30 will now be described with reference to
Turning now to
Turning now to
Through the provision of three distinctive beam patterns 40, 50, 60 provided by primary, secondary and tertiary light units 26, 28, 30, the controller 32 may operate the light units in different combinations to produce particular beam patterns based on inputted variables. For example, when vehicle speed 34 is below a predetermined value such as about 40 kmph to 100 kmph (25 mph to 62 mph) the controller 32 may only energize the primary light units 26 to produce the basic beam pattern 40 depicted in
With reference to those figures,
Turning now to
When the controller 32 receives weather information 35 or user input 38 indicating fog, a fog beam pattern 66 may be produced as shown in
It can also be seen that the controller 32 can tailor the operation of light units 22, 24 based on the direction 36 of the vehicle 14. For example, when the road 15l turns to the left as depicted in
A similar principle may be applied to provide a right beam pattern 70 as depicted in
Accordingly, it will be recognized by those skilled in the art that through the use of primary, secondary and tertiary light units 26, 28, 30 in each left and right light assembly 22, 24, the particular shape of their beam patterns 40, 50, 60 and the selective energization of these light units by a controller 32 receiving various inputs on speed 34, weather 35, direction 36 and user input 38, unique beam patterns 40, 60, 62, 64, 66, 68, 70 may be employed and adapted to various driving situations and conditions to improve illumination of the road and reduce glare to oncoming traffic.
The foregoing description of various embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Numerous modifications or variations are possible in light of the above teachings. The embodiments discussed were chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally, and equitably entitled.
Number | Date | Country | Kind |
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PV 2005-435 | Jul 2005 | CZ | national |