Patent Abstract:
Automotive lamps are configured having at least one array of light emitting diodes (LEDs) supported within the lamps. A bezel is positioned in each lamp adjacent to the LEDs, the bezel having a dark surface, the dark surface having a high gloss finish with reflector shaped surfaces to reflect light from the LEDs while absorbing visible light from external sources. A lens of light transmitting material covers the array of LEDs. The automotive lamp is especially useful as a rear combination lamp having red LEDs serving both tail light and stop light functions, as well as amber or red LEDs providing turn and hazard signals. A center, high-mounted stop lamp (CHMSL), also using an array of LEDs surrounded by a dark bezel with high gloss reflector shaped surfaces, is used in combination with a pair of the rear combination lamps. In one embodiment the rear combination lamps include side marker LEDs.

Full Description:
FIELD OF THE INVENTION 
     The present invention is directed to dark look LED automotive lighting. More particularly, the present invention is directed to dark look LED automotive lighting, used as but not limited to external signal lighting. 
     BACKGROUND OF THE INVENTION 
     Automobile manufacturers are constantly improving vehicles by improving reliability, improving performance and developing devices which may be useful in succeeding generations of vehicles. As an aspect of vehicle design, automotive lighting evolves as vehicles improve. As automotive lighting evolves, there is a general need to minimize power consumption and to enhance performance and reliability, while at least maintaining and perhaps improving conspicuity. With respect to automotive lighting, it is important to have lighting schemes which not only have a pleasing appearance, but for the benefit of prospective customers, differentiate vehicles using those lighting schemes from other vehicles. 
     Since LEDs draw relatively little current, can last the life of a vehicle, illuminate almost instantaneously and produce little heat; LEDs are of interest as automotive lighting arrangements evolve. An attractive and distinct appearance is important for LED lamps located on the rear of the vehicle because drivers necessarily focus most of their attention on the rear surface of vehicles in front of them. This is because tail lamps of preceding vehicles indicate the presence of preceding vehicles at night, and brake, turn and hazard lamps at any time caution following vehicles. 
     Ambient sunlight is a consideration when designing automotive lighting because ambient sunlight can obscure signal lamp functions when reflected therefrom. Since individual LEDs are typically not as bright as individual incandescent bulbs currently used as signal lamps on automotive vehicles, the reflection of ambient sunlight from signal lamps is a concern. 
     SUMMARY OF THE INVENTION 
     In view of the aforementioned considerations, the present invention is directed to an automotive lamp comprising an array of light emitting diodes (LEDs) supported within the lamp. A bezel having a dark surface for absorbing visible light from external sources is positioned adjacent to the LEDs. The dark surface of the bezel has a high gloss finish or other reflective area at least adjacent the LEDs to reflect light from the LEDs, while the dark surface absorbs visible light from external sources. A lens of light transmitting material covers the array of LEDs. 
     In a further aspect of the invention, the dark surface is substantially black and the lens is clear. 
     In another aspect of the invention, the automotive lamp is a rear combination lamp assembly including a first array of LEDs which emit red light to function both as a tail light and as a brake light. The rear combination lamp assembly further comprises a second array of LEDs that in one embodiment emit amber light to provide turn and emergency signals which flash. A bezel surrounds the LEDs and is substantially black in color to absorb incoming light from exterior sources, such as sunlight, and includes a gloss finish to reflect light rearwardly from the LEDs. The bezel is mounted in a housing and a lens is positioned over the bezel and the arrays of LEDs. 
     In a preferred arrangement of the LEDs within the rear combination lamp assembly, the LEDs are arranged in vertical columns and at least a rearwardly facing reflector is positioned adjacent to the columns of LEDs. 
     In a preferred embodiment of energizing the LEDs, the LEDs of the first array are connected to a power supply which is connected with both a road light control system and a brake system in a vehicle. The power supply has a first mode of a reduced duty cycle for illuminating the LEDs of the first array only as taillights, and has a second mode activated by the braking system for delivering current at a higher percentage of the duty cycle to the LEDs of the first array. This illuminates the LEDs of the first array more brightly then when used as tail lights in order to provide brake lights. In still a further aspect of the invention, the power supply is connected to the second array of LEDs that emit flashing amber or red light and provides current thereto at a higher percentage of the duty cycle to contrast with the tail lights provided by the first array, as well as to be visible in conjunction with the second array, if the first array is brightly lit indicative of the vehicle&#39;s brakes being applied. 
     In still another aspect of the invention, the aforedescribed automotive lamp is used as a center, high mounted, stop lamp (CHMSL) comprising an array of red light emitting LEDs surrounded by a bezel which is substantially black in color to absorb incoming light from exterior sources while having a gloss finish providing reflector elements adjacent to the LEDs to reflect light from the array of red LEDs rearwardly. The bezel is mounted by a housing and a lens is positioned over the bezel and the array of red LEDs. 
     In further aspects of the CHMSL the red LEDs are arrayed in a line and the lens is clear. 
     In still another aspect of the invention the aforedescribed automotive lamps are utilized in combination in an arrangement of rear signal lamps on an automotive vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various other features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a schematic view illustrating light from the sun illuminating the rear of an automotive vehicle; 
         FIG. 2  is a rear view of the automotive vehicle of  FIG. 1 ; 
         FIG. 3  is a rear view similar to  FIG. 2  but showing tail lamps of the automotive vehicle illuminated; 
         FIG. 4  is a view similar to  FIGS. 2 and 3  but showing stop signals illuminated; 
         FIG. 5  is a view similar to  FIGS. 2–4  but showing a left turn signal illuminated; 
         FIG. 6  is a perspective view of a rear combination lamp configured in accordance with the principles of the present invention; 
         FIG. 7  is an elevation taken along line  7 — 7  of  FIG. 6  showing optional side marker illumination; 
         FIG. 8  is a rear view of a center, high mounted, stop lamp (CHMSL) configured in accordance with principles of the present invention; 
         FIG. 9  is an elevation taken along line  9 — 9  of  FIG. 8 , and 
         FIG. 10  is a schematic diagram showing a power supply arrangement used with each of the rear combination lamps of  FIGS. 2–5 , shown in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1  there is shown an automotive vehicle  20  having a rearwardly facing area  21  on which is disposed a pair of rear combination lamps  23   a ( b ) and a center high mount stop lamp (CHMSL)  24 . The pair of rear combination lamps  23   a ( b ) and the CHMSL  24  are dark in color so as to not reflect exterior light rays, such as light rays  25  and  26  from an external source such as the sun  27 , back to an observer  28  in a following vehicle. This is because dark objects absorb rather than reflect visible light. Since the rear combination lamps  23   a ( b ) and CHMSL  24  absorb the externally emitted light rays  25  and  26 , light rays  29  and  30  emitted by the rear combination lamps and CHMSL are not obscured by the light rays  25  and  26 , and are thereby clearly visible to the observer  28 . As will be explained hereinafter, this is accomplished by having dark surfaces of the lamps  23   a ( b ) and  24  black, or substantially black in color, with a glossy surface, so that when the lamps are illuminated, they are not obscured by exterior light sources, such as light from the sun  27  or from other sources such as headlights of following vehicles. 
     Referring now to  FIGS. 2–5  where the rear area  21  of the vehicle  20  is shown,  FIG. 2  shows the vehicle as it appears to a following driver in normal daylight. In  FIG. 2 , the rear combination lamps  23   a  and  23   b  and the CHMSL lamp  24  are not illuminated, whereas in  FIG. 3 , the rear combination lamps  23   a  and  23   b  are illuminated as tail signal lights  31   a  and  31   b  (preferably red in color) when the vehicle is traveling at night or twilight, in fog or in any other situation, such as with a group of other vehicles (convoy), where tail lights of vehicles are illuminated. 
     In  FIG. 4 , red signal stop lights  32   a  and  32   b  are substantially brighter than the red signal tail lights  31   a  and  31   b  of  FIG. 3 , notifying a following vehicle that brakes have been applied in the vehicle  20 . In addition to illuminating the red signal stop lights  32   a  and  32   b  in the combination lamps  23   a  and  23   b , respectively, a red signal stop light  34  in the CHMSL  24  is illuminated. The red signal stoplights  32   a , 32   b  and  34  are substantially brighter than the red signal tail lights  31   a  and  31   b , providing a contrasting stop signal to following vehicles. 
     Referring now to  FIG. 5 , a left turn signal is indicated by the rear combination lamp  23   a  as a preferably amber (or red) turn signal light  35   a  which flashes. While “amber” is a required color for some turn signals in jurisdictions, such as the European Union; “red” or “white” is acceptable in other jurisdictions. For emergency vehicles “orange” or “blue” lights are employed and for funerals “violet” lights are also used in various ways. For conventional vehicles the general practice is to have red lamps for tail, stop and rear fog lights; amber or red lamps for turn and hazard signals, and white lamps for backing lights Since the turn signal light  35   a  both flashes and is bright, it contrasts with both the tail signal lights  31   a  and  31   b  and the stop signal lights  32   a  and  32   b . If a hazards situation is being conveyed from the driver of the vehicle  20  to other drivers, then the turn signal light  35   a  flashes in unison with a turn signal light  35   b.    
     Referring now to  FIG. 6  one of the rear combination lamps  23   a  is shown, the other rear combination lamp  23   b  being a reverse image thereof. As is seen in  FIG. 6 , both the tail signal light  31   a  and the stop light signal source  32   a  are provided by a first array  40  of first LEDs  42  that emit red light. The turn signal light  35   a  is provided by a second array  44  of second LEDs  46  that preferably emit either flashing amber or flashing red light. In the embodiment of  FIGS. 6  the first array  40  of first LEDs  42  and the second array  44  of second LEDs  46  are linear and are arranged in vertical columns to provide illumination proximate the vertical edges of the rear area  21  of the vehicle  20  (see also  FIGS. 2–5 ). Beneath the two columns formed by the first and second arrays  40  and  44  of the LEDs  42  and  46 , respectively, is a passive reflector  47  having a rear panel  48  and a side panel  49 . The rear panel  48  is primarily visible from the rear area  21  of the vehicle  20  and the side panel  49  primarily visible from the side of the vehicle. 
     The LEDs  42  and  46  are surrounded by a bezel  50  which is dark in color to absorb rather than reflect exterior light sources such as sunlight (or following headlights), whereby the arrays of LEDs  40  and  44  are not obscured by reflected light rays from exterior light sources (see  FIG. 1 ) when viewed by a following driver. Preferably, the bezel  50  is black or substantially black so that substantially all of the light rays  25  and  26  from an external source such as the sun  27  (see  FIG. 1 ) are absorbed, however the bezel  50  has a high gloss surface at least in areas such as areas  52  and  54 , which are directly adjacent to and extend obliquely with respect to the LEDs  42  and  46 . Since at least these surfaces  52  and  54  of the bezel  50  are glossy, these surfaces reflect portions  56  and  58  of light emitted by the LEDs  42  and  46 , respectively. Portions of emitted light which do not reflect from the glossy surfaces  52  and  54  of the bezel  50  are directed rearwardly in a direct line of sight to the following observer. By stepping the second array  44  of LEDs  46  with respect to the first array  40  of LEDs  42 , there is less interference between the stop signal light  32   a  and turn signal  35   a emitted from the LEDs  42  and  46 , respectively. The portions  52  of the bezel  50  adjacent to the LEDs  42  are above and below the LEDs  42  so as to reflect substantially all of the laterally emitted light from the LEDs  42  back toward the following vehicle. At least some of the light from the LEDs  42  emits laterally, providing at least some side illumination for the rear combination lamps  23   a  and  23   b.    
     The bezel  50  is preferably made of black polycarbonate and the reflective surfaces  52  and  54  may either be at least glossy portions of the black polycarbonate or may be in the shape of small, non-metalized reflector elements surrounding each of the LEDs  42  and  46 . In the preferred illustrated embodiment the entire bezel is molded of black polycarbonate with a continuous glossy surface molded therewith. 
     The bezel  50  is attached to a housing  70  by a pair of metal push-in clips and at least one screw utilizing a rubber sealing gasket (neither of which is shown) so that the bezel is structurally stable with respect to the housing. In a preferred embodiment, the LEDs  42  project through openings  74  in the bezel  50  and the LEDs  46  project through openings  76  in the bezel, the openings  74  and  76  being adjacent the reflective surfaces  52  and  54  of the bezel. 
     The first array  40  of LEDs  42  is mounted on a stamped metal circuit  80  that is press fitted or otherwise attached to the back surface of the bezel  50 . The second array  44  of LEDs  46  is attached to a stamped metal circuit that is also press fitted or otherwise attached to the back surface of the bezel. Alternatively, the stamped metal circuits are attached to surface of the housing. 
     Disposed over the arrays  40  and  46  of LEDs  42  and  46  is a lens  90 . The lens  90  is preferably made of crystal clear (non-colored), medium impact, acrylic plastic having a black acrylic frame around the entire periphery of the lens. The frame is preferably molded integrally to the lens and the combination of the lens and the frame are adhered to the housing  70  using a two-part polyurethane adhesive  91  to combine the housing, lens and lens frame in an integral, closed structure protecting the LEDs  42  and  46 . The housing  70  is attached removably to the rear of the vehicle  20  ( FIGS. 1–5 ) in a conventional manner by using, for example, screws or bolts to mount the rear combination lamp  23   a  on the vehicle, the rear combination lamp  23   b  being generally configured and mounted on the vehicle in the same manner. 
     As is seen in  FIG. 7 , for certain markets, red side marker LEDs  93  are required. In these situations, the bezel  50 ′ is provided with an additional opening  94  and the LEDs  93  are supported in the housing  70  by a printed circuit board  95 . Preferably, a pair of LEDs  93  provide a third array  96  of LEDs in each of the rear combination lamps  23   a  and  23   b  to provide side marker illumination for the two rear combination lamps. In a preferred embodiment, the LED or LEDs  93  are mounted to project light through a light transmitting portion of the side marker reflective panels  49  of each rear combination lamp  23   a  and  23   b.    
     Referring now to  FIGS. 8 and 9  where the center, high-mounted stop lamp (CHMSL)  24  is shown in isolation, it is seen that the stop signal light  34  of the CHMSL is comprised of an additional array  100  of individual red LEDs  102 . In the illustrated embodiment there are  34  LEDs. While a linear array  100  of LEDs  102  is a preferred arrangement of a CHMSL for a vehicle such as an SUV, this third array  100  of LEDs  102  may be arranged in other configurations, such as lines of LEDs arranged one above the other, or in any other arrangement conveying a signal to a following driver to “stop.” 
     As is seen in  FIG. 9 , the additional array  100  of LEDs  102  providing the CHMSL signal light  34  cooperate with a bezel  104  that has openings  106  therein through which red light from the LEDs passes. The bezel  104  is of a dark material which absorbs exterior light such as ambient sunlight or light from a following headlight, but has reflective surfaces  108  at least adjacent the LEDs  102 . In a preferred embodiment, the bezel  104  is made of a dark plastic, such as black polycarbonate, having a glossy surface which provides the reflective surfaces  108  at least adjacent each LED  102 . The LEDs  102  are mounted on a circuit board  110  positioned behind the bezel  104 , the circuit board being affixed to a housing  112 . The housing  112  is preferably made of a plastic material and supports a clear plastic lens  114  preferably made of an acrylic material. The clear plastic lens  114  preferably has a black acrylic frame. The clear plastic lens  114 , which is preferably a crystal clear acrylic, is bonded to the housing  112  with a two-part polyurethane adhesive  116  to provide a permanently closed integral structure that protects the additional array  100  of red LEDs  102  for the life of the CHMSL  24 . 
     Referring now to  FIG. 10  there is shown a power supply, which is referred to in the art as an LED drive module or an LDM. An LDM  130   a  is mounted in the housing  70  of the left rear combination lamp  23   a  and an LDM  130   b  is mounted in the housing  70  of the right rear combination lamp  23   b . The LDM modules  130   a  and  130   b  use constant vehicle current at  9 – 16  volts DC. When the outboard lights  31   a  and  31   b  (see  FIG. 3 ) are functioning as taillights, the associated LDMs  130   a  and  130   b  are operating in a first mode at a 5% duty cycle to provide current to the red LEDs  42  of the first array  40  in each of the rear combination lamps  23   a  and  23   b . Consequently, the red LEDs  42  emit light at a reduced intensity when in the first mode. 
     When the brake pedal of the vehicle  20  is pressed, the LDMs  130   a  and  130   b  change to a second mode during which the duty cycle is increased, preferably to a full duty cycle, which substantially brightens the red LEDs  42  in both rear combination lamps  23   a  and  23   b , signaling a following driver that brakes have been applied in the vehicle  20 . 
     The CHMSL light  34  is not modulated by the LDMs  130   a  and  130   b , but is connected directly to the DC electrical system through a brake pedal detector and is illuminated immediately when the brake pedal is pressed (not shown) with current preferably at a full duty cycle, so that there are three rearwardly facing brake signal lights  32   a , 32   b  and  34  (see  FIG. 4 ) displayed to following vehicles when the brake pedal in vehicle  20  is pressed. 
     The rear turn signal lights  35   a  and  35   b  always operate at a full duty cycle and are therefore always bright when flashing to indicate a left turn  35   a  or a right turn  35   b , or when both are flashing in conjunction to indicate an emergency situation. The second LEDs  46  contrast with the first LEDs  42  in the first arrays  40  of the two rear combination lamps  23   a  and  23   b . This contrast indicates to following vehicles that the vehicle  20  is turning or that the vehicle is aware of a hazardous condition. The turn signal lights  35   a  and  35   b  flash together when a caution switch in the vehicle  20  is activated to indicate the presence of a hazard to following drivers. The turn signal lights  35   a  and  35   b , positioned inboard of the tail and stop signal lights  31   a  and  31   b , are either red or amber and contrast markedly with the red tail lights  31   a  and  31   b  and stop lights  32   a  and  32   b  because the turn signal lights  35   a  and  35   b  continuously flash. 
       FIG. 10  is the actual circuit diagram of the illustrated embodiment. Although the LEDs  42  and  46  are each physically in single columns in the other drawing figures, other physical arrangements of the LEDs  42  and  46  may be used, such as but not limited to circular or polygonal arrangements. 
     As seen in  FIG. 10 , if a side marker function is utilized with the rear combination lamps  23   a  and  23   b , then the LED  93  or the array  96  of LEDs  93  are preferably energized directly by the vehicles DC electrical system to always preferably illuminate at a full duty cycle. The CHMSL  24  is preferably also energized by  9 – 16  volt constant DC current at a full duty cycle taken directly from the electrical system of the vehicle  20 . 
     The present invention is also applicable to front parking and directional signal lights configured in substantial similarity with the rear combination lights  23   a  and  23   b , wherein turn signal LEDs have dark bezels with a reflective portion or element adjacent to the LEDs, so as to indicate turns when flashed one at a time to indicate turning direction, or in unison, to indicate an emergency condition. These lights may also be used as parking lights using amber or white LEDs with dark color bezels having reflective surfaces, such as the aforementioned glossy surfaces. 
     From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing form the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.

Technology Classification (CPC): 5