WO1998002855A1

WO1998002855A1 - Led signal lamp assembly with multi-color capabilities

Info

Publication number: WO1998002855A1
Application number: PCT/US1997/012495
Authority: WO
Inventors: Hyman Grossman; Michael Wayne Mayer
Original assignee: Dialight Corporation
Priority date: 1996-07-16
Filing date: 1997-07-16
Publication date: 1998-01-22
Also published as: AU3884497A

Abstract

An LED signal lamp (25) having multi-color capabilities which includes an enclosure body or housing (1) and a circuit board (3) mounted within the enclosure or housing. LEDs (5) of different colors are mounted on the circuit board (3) and define a predetermined shape. The lighting of LEDs (5) of a selected color permits the illuminated presentation of the predetermined shape in the selected color.

Description

TITLE OF THE INVENTION

LED SIGN.AL .LAMP ASSEMBLY WITH MULTI-COLOR CAPABILITIES

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an LED signal lamp assembly with multi-color capabilities which can be used for a traffic turn signal. In the present invention, LEDs of different colors are mounted on a circuit board to define a predetermined shape and provide for a predetermined shape having different colors.

Discussion of the Background

Recently, municipalities have indicated that traffic turn signals should have both green and amber light indications where previously green by itself was considered adequate. Stacking the turn signal of an additional color other than green beneath an existing green turn signal results in a low clearance problem with respect to trucks passing through the intersection where the turn signal is located. This also makes the turn signal more susceptible to wind and increases the structural loading.

Some municipalities have addressed this drawback by placing turn signal lamps alongside other traffic signals. However, this approach may create a problem since the adjacent positioning of the turn signal lamps and the other traffic signals may lead to confusion with respect to distinguishing between the turn signal lamps and the traffic signals.

Another approach has been to use a green/yellow bi- odal arrow that employs two lamps with flexible fiber optics. Each of these lamps is typically a filtered halogen bulb. This approach has a drawback in that filtered halogen bulbs have a limited lifetime and are expensive.

OBJECT OF THE INVENTION Accordingly, an object of the present invention is to provide a signal lamp which utilizes LEDs of multiple colors so as to provide for a predetermined shape which can be selectively illuminated to different colors. The utilization of LEDs offers advantages over filtered halogen bulbs in that they provide for a greater lifetime of the assembly and are less expensive to use.

SUMMARY OF THE INVENTION The present invention provides a multi-color signal lamp which utilizes a combination of the LEDs of multiple colors and drive circuits so as to provide for an efficient and consistent illumination of the LEDs. Although single- color traffic arrows employing LEDs have been utilized, Applicants believe that they are the first to discover the utilization of LEDs in a multi-color assembly to form a predetermined shape in combination with the coordination of the drive circuits for illuminating the LEDs.

The present invention also provides an LED signal lamp assembly with multi-color capabilities which comprises a housing; a circuit board assembly mounted within the housing; a plurality of LEDs mounted on the circuit board assembly so as to define a predetermined shape; and a transparent lens mounted at an opening of the housing.

BRIEF DESCRIPTION OF THE DRAWINGS In describing the preferred embodiments of the present invention illustrated in the drawings, specified terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which can operate for a similar purpose.

A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description, particularly when considered in connection with the accompanying drawings, wherein: Figure 1 is a front view of the multi-color signal lamp of the present invention in which the LEDs are visible;

Figure 2 is a side view of Figure 1 showing the signal lamp of the present invention;

Figure 3 is a bottom view of the signal lamp assembly of Figure 1; and

Figure 4 is a schematic illustration of the drive circuits for driving the LEDs of Figure l.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, Figure 1 illustrates a front view of a signal lamp 25 of the present invention, while Figure 2 illustrates a side view of Figure 1. As illustrated in Figures 1 and 2, the signal lamp 25 comprises an enclosure body or housing 1 in which a printed circuit board 3 can be mounted. On the printed circuit board 3 a plurality of LEDs 5 are mounted. In the embodiment disclosed in the figures, the LEDs 5 which are designated by the letter "A" are amber LEDs, while the LEDs 5 which are designated with the letter ^MG" are green LEDs. However, it is recognized that the color of the LEDs is not limited to green and amber, and other colors such as red can be utilized. The LEDs 5 are mounted on the circuit board 3 so as to form a predetermined shape or pattern. The predetermined shape or pattern illustrated in Figure 1 is an arrow. However, it is recognized that the shape does not have to be limited to an arrow and that other shapes can be employed depending on the use of the signal lamp. In the embodiment disclosed in Figure 1, the signal lamp is utilized as a traffic signal lamp, and thus the LEDs 5 form an arrow shape.

Also illustrated in Figure 2 is a lens 7 which can be a transparent untinted lens. The lens 7 is mounted onto the housing 1 so as to enclose the printed circuit board 3 and the LEDs 5 mounted on the printed circuit board 3 in the manner illustrated in Figure 2. Power can be supplied to the printed circuit board 3 and LEDs 5 via a power cable and terminal arrangement 9 illustrated in Figure 2.

Referring to Figures 1 and 3 which respectively show front and rear views of the pattern formed by the LEDs 5, it can be seen that the amber (A) and green (G) LEDs are adjacently and alternately positioned such that when all of the LEDs of the same color are illuminated they can provide for an arrow shape of that particular color. Therefore, the illumination of the amber LEDs alone will provide for an amber arrow shape, while the illumination of only the green LEDs would provide for a green arrow shape. Figure 4 is a schematic example of a drive circuit arrangement for separately illuminating the green LEDs 5 and the amber LEDs 5. In the examples illustrated in the figures, 72 green LEDs and 72 amber LEDs are illustrated. However, this is just one example of the number of LEDs that can be utilized. It is recognized that the number of LEDs can be greater or lesser than the disclosed example and depends on design considerations.

With respect to the drive circuit arrangement illustrated in Figure 4 , the embodiment illustrated shows a first LED drive circuit 11 for illuminating the green LEDs 5 and a second LED drive circuit 15 for illuminating the amber LEDs 5. Each of the drive circuits 11 and 13 illustrated in Figure include the noted resistors, capacitators, and diodes illustrated in Figure 4. The values shown in Figure 4 are given as an example, and it is recognized that the values for the resistor, capacitators, and diodes can be changed based on design considerations.

If additional colors are to be utilized, additional drive circuits can be added. Applicants have discovered that green LEDs are more efficient when driven with direct current, while other color LEDs are more efficient when pulsed. In the embodiment illustrated, the first LED drive circuit 11 is a DC circuit, while the second drive circuit 15 can be a full-wave rectified 50-60 Hz AC input. Applicants note, however, that the drive circuit for driving the LEDs of the present invention is not limited to the circuit shown and other potential embodiments including driving both with AC or DC circuits or providing for one common drive circuit, can be utilized.

Accordingly, during use of the disclosed embodiment, when the first drive circuit 11 illustrated in Figure 4 is actuated, only the green LEDs 5 of Figure 1 are illuminated so as to provide for a green arrow. When the second drive circuit 15 is actuated, only the amber LEDs 5 are illuminated so as to provide for an amber arrow.

Therefore, the present invention provides for a signal lamp having a predetermined shape such as an arrow which can be controlled to illuminate the shape in different colors in an efficient manner so provide for maximum viewing of the shape in different colors. The utilization of the LEDs in different colors also provides for a single multi-color unit with an increased lifetime and which is inexpensive.

Although two colors are shown, other colors such as red may be provided in one assembly. By utilizing additional colors, precautions need to be taken to assure that color-blind people can distinguish the meaning between the colors.

Also, as noted above, although an arrow shape is shown, it is recognized that other shapes can be utilized. Additionally, the number of LEDs utilized depends on design considerations.

Although it is described that the signal lamp can be utilized for a traffic turn signal, it is also recognized that the signal lamp of the present invention can be utilized in other lighting applications where the illuminated presentation of shapes having different colors is desired.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

CLAIMS :

1. An LED signal lamp assembly have multi-color capabilities, comprising:

(a) a housing;

(b) a circuit board assembly mounted within said housing;

(c) a plurality of LEDs of a first color mounted on said circuit board assembly so as to define a shape;

(d) a plurality of LEDs of a second color mounted on said circuit board assembly so as to define said shape; and

(e) a transparent lens mounted at an opening of said housing.

2. An LED signal lamp assembly according to claim 1, wherein said shape formed by said plurality of LEDs is an arrow.

3. An LED signal lamp assembly according to claim 2, wherein:

(a) said first color green; and

(b) said second color is amber. . An LED signal lamp assembly according to claim 3 , and further comprising:

(a) a first drive circuit for said plurality of first LEDs ; and

(b) a second drive circuit for said plurality of second LEDs .

5. An LED signal lamp assembly according to claim 4, wherein said green and amber LEDs are adjacently and alternately mounted on said circuit board to form said arrow, such that an actuation of said first drive circuit produces an illuminated green LED arrow and an actuation of said second drive circuit produces an illuminated amber LED arrow.

6. An LED signal lamp assembly according to claim 4, wherein:

(a) said first drive circuit is a DC circuit; and

(b) said second drive circuit is a full-wave rectified AC circuit.

7. An LED signal lamp assembly according to claim l, wherein said transparent lens is an untinted lens.

8. An LED signal lamp assembly according to claim 1, wherein said signal lamp is part of a traffic light assembly.

9. An LED signal lamp assembly according to claim 1, and further comprising a plurality of LEDs of a third color mounted on said circuit board assembly so as to define said shape.

10. An LED signal lamp assembly according to claim 9, wherein said third color is red.

11. An LED signal lamp assembly according to claim 1, wherein said first plurality of LEDs and said second plurality of LEDs are adjacently and alternately positioned on said circuit board to form said shape.

12. An LED signal lamp assembly according to claim 11, wherein:

(a) a lighting of said first plurality of LEDs produces an illuminated shape having said first color; and

(b) a lighting of said second plurality of LEDs produces an illuminated shape having said second color.