Abstract:
A directional indicator light for a marine vehicle has red and green LEDs positioned on port and starboard sides of the marine vehicle, respectively. The indicator includes a lens for focusing and directing the light provided by the LEDs. The indicator can be sealed to prevent exposure to the marine environment. The LEDs are arranged in arrays and connected in parallel, to prevent the failure of one LED from extinguishing an entire directional indicator. The directional indicator has a lower profile and consumes less power than conventional marine directional indicators.

Description:
RELATED APPLICATION  
       [0001]    This application is based on and claims benefit of U.S. Provisional Application Serial No. 60/310,936, filed Aug. 8, 2001, entitled DIRECTIONAL INDICATOR LIGHT FOR BOAT, to which a claim of priority is hereby made. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention relates to navigation lights and more specifically to a navigation lamp that indicates travel direction.  
         BACKGROUND OF THE INVENTION  
         [0003]    The invention concerns a navigation lamp employing light emitting diode lights for use on a boat for indicating its direction of travel. Typically, there is a navigation lamp or light mounted on the bow and/or stern of the boat with a red lamp on the port side and a green lamp on the starboard side so that the direction of travel of the boat is indicated to other boats.  
           [0004]    Presently, the navigation lamp is an incandescent lamp with one bulb. Typically, an incandescent lamp light source generates a yellow/white color. The indicator light is provided with appropriately placed color tinted lenses for indicating green on the starboard side and red on the port side. The incandescent lamp is housed in a housing which is sealed closed to protect the wiring, the bulb and contacts from moisture. The lens is a two piece molded tinted lens that is sealed to the lamp housing. There is typically a metal cover on the lamp that conducts heat generated by the bulb away from the lamp. Since this lamp usually has only a single bulb light source, if the bulb burns out, the entire directional signal indication is lost until the bulb is replaced. Further, the two lamps (red and green source) consume substantial electrical power and requires considerable volume, while averaging about two inches in height.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention, there is provided a single directional indicator for a boat that is composed of sets of two or more LEDs having different color outputs. The LEDs are separated into red and green color sections in a single assembly and are arranged to show a boat direction. The LED arrangement is provided with a common lens to cover the LEDs, and the LEDs are configured on a printed circuit board for power control and physical support. The LEDs use less power than incandescent bulbs. Moreover, the directional indicator light composed of LEDs continues to work even should one or more LEDs in either set bum out. In addition, the LEDs are smaller in size and produce much less heat than the incandescent bulb of the prior art. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    The present invention is described below in detail with reference to the drawings, in which:  
         [0007]    [0007]FIG. 1 is a schematic perspective of a unitary navigation lamp according to the present invention;  
         [0008]    [0008]FIG. 2 is a side cross-section of the present invention;  
         [0009]    [0009]FIG. 3 is an exploded perspective view; and  
         [0010]    [0010]FIG. 4 is a circuit diagram according to the present invention;  
         [0011]    [0011]FIG. 5 a  is a plan view of another embodiment of the present invention; and  
         [0012]    [0012]FIG. 5 b  is a side view of the embodiment of FIG. 5 a.    
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    Referring now to FIGS. 1 and 2, there is shown a single unitary housing  10  that emits a green light to the starboard side  12  of a vehicle on which it is mounted and a red light to the port side  14  of the vehicle. According to the invention, the starboard light output and the port light output is generated by a dedicated light source in the form of at least one, and preferably several, solid state light emitting diodes (LED) of the selected color, that is, red and green. The LEDs are arranged in essentially semicircular arrays, one array of red LEDs  23  and another of green LEDs  21 . The two arrays of red and green LEDs  23 ,  21  are positioned to produce red light on the side of the navigation lamp facing the port side of the vehicle, and green light towards the starboard side. The LEDs  21 ,  23  are positioned on a printed circuit board (not shown) and each LED is aimed to provide the required radially outward directed output in the selected color. A lens  22  over a base  24  surrounds the LEDs and has a top portion  26  over the lens  22 . Top portion  26 , lens  22  and base  24  can be sealed together to prevent moisture or other environmental contaminants from entering the navigation lamp.  
         [0014]    The circuit board holding the LEDs is connected to a power source (not shown) through a switch (not shown) to turn the lamp on and off. The combined electrical current drawn by all of the LEDs is typically expected to be approximately 20% of the electrical current drawn by a standard incandescent bulb generating the equivalent amount of illumination. In addition, heat generated by the lamp is expected to be greatly reduced in comparison with a standard incandescent bulb. The reduced heat output permits a smaller profile lamp housing to be used, since not as much heat needs to be conducted away from the lamp. That is, the housing need not be designed with a large heat conduction capacity that would result in a bulkier size.  
         [0015]    According to the present invention, the LEDs  21 ,  23  or the molded lens  22  may be colored to provide the appropriate light color output. The molded lens  22  around the lamp is optically designed for maximum illumination output of the light provided from the LEDs. Preferably, as shown in FIG. 2, lens  22  consists of respective semicircular lens  30 ,  31  on each side of the lamp giving the entire combined lens array a circular shape. Each of the semicircular lenses  30 ,  31  is a compound lens for maximizing illumination output. For example, each may be a Fresnel lens, which concentrates the output in desired directions. Base  24  can be opaque and mount to a boat on which the lamp is to be used.  
         [0016]    LEDs  21 ,  23  can be connected according to the circuit as shown in FIG. 4. The configuration of this circuit is such that if one of the LEDs  21 ,  23  should be extinguished or bum out for any reason, other LEDs  21 ,  23  remain illuminated, without loss of indication. This can be achieved by connecting the LEDs  21 ,  23  in parallel as in FIG. 4. The LEDs  21 ,  23  are shown grouped together so that if one of LEDs  21 ,  23  becomes inoperative, other LEDs  21 ,  23  do not become inoperative. LEDs  21 ,  23  can be grouped in any manner desired, as long as they are mainly connected in parallel to permit continued output of a red or green indication even if a given LED fails.  
         [0017]    Referring now to FIG. 3, another embodiment of the invention, in which a top cover  25  includes the lens  22  is shown. Top cover  25  need not be of metal, since LEDs  21 ,  23  are cool light sources and bulb heat need not be conducted away. Because LEDs  20  are small in size and diameter, the height of the lens  22  in top cover  25  is not dictated by the diameter of an incandescent bulb, but rather can be set as small as desired for aesthetics and ease of mounting. The lens  22  should have a sufficient width and height so that a semicircular band of light can be emitted through the lens  22  to be visible across an appropriate distance and provide an indication of navigational direction.  
         [0018]    Referring now to FIGS. 5 a  and  5   b , another embodiment of the present invention is shown. The embodiment includes a molded outer case  40  that has an outer edge serving as the lens  22 . Lens  22  has a convex contour with respect to case  40  that assists in dispensing light in desired directions. Green and red light output portions  12  and  14  respectively put out directed light over an angle of 135° each. A remaining 90° portion  46  of case  40  has internal deflectors or reflectors (not shown) to direct internally oriented light back through lens  22  to increase light output. A top portion  48  of case  40  is opaque or translucent to decrease the amount of light that can escape from the top of the directional indicator. By providing portions  46  and  48  with reduced output or reflected light properties, rearward and upward directional light indication is prevented.  
         [0019]    Case  40  is molded as one piece with portions  46  and  48  arranged to reflect or decrease light output as desired. In addition, lens  22  is molded into case  40 , along with Fresnel elements (not shown) to increase light output and provide colimnated or directed light. Case  40  is generally molded in a cup shape with portions  46 ,  48  having desired light reflective or light attenuating characteristics, respectively. The molding process includes lens  22  and Fresnel elements so that case  40  forms a complete outer housing for the directional indicator according to the present invention.  
         [0020]    Case  40  also has orienting features  44  provided in the molding process, such as recesses or bosses. Orienting features  44  cooperate with reciprocal features on base  40  to properly orient the directional indicator with respect to base  24 . Base  24  is installed on the vehicle with an appropriate orientation to permit case  40  to be easily oriented on base  24  in the proper direction through orienting features  44 .  
         [0021]    Base  24  includes a circuit board  27  and wiring to supply power to the directional indicator and LEDs  21 ,  23 . LEDs  21 ,  23  are mounted on circuit board  27 , which is mounted on base  24  and connected to a power source to provide appropriate power output for desired indicator illumination. Base  24  is mounted to the vehicle, and case  40  is mounted to base  24  so that the circuit and LEDs  21 ,  23  are covered and enclosed by case  40 . Base  24  and case  40  can be sealed to each other and to the vehicle to avoid contamination by exposure to hostile environments. The assembly of base  24  and case  40  provide a simplified two piece construction for the directional indicator, with a low height profile and small footprint. For example, the entire assembly can be about {fraction (3/4)} inch in height, while having a diameter of about 2-{fraction (1/4)} inches. Base  24  can also include support portions for holding the circuit board  27  in a fixed position.  
         [0022]    The directional indicator is typically powered with a 12V DC source, however, any type of power configuration can be used, as long as the LED circuit can convert the supply power to operate the LEDs. The indicator can be operated with an ON/OFF switch through an operator console for ease of use. In addition, the indicator can be used on a number of types of vehicles such as power boats, personal watercraft, and the like, because of its simplified design and small profile.  
         [0023]    Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.