WO2014094049A1

WO2014094049A1 - Led lighting system and method

Info

Publication number: WO2014094049A1
Application number: PCT/AU2013/001482
Authority: WO
Inventors: Adam Paul MIDDLETON
Original assignee: Ama Group Limited
Priority date: 2012-12-18
Filing date: 2013-12-18
Publication date: 2014-06-26
Also published as: AU2013101789A4; AU2013362886A1

Abstract

A light assembly enables effective illumination of advertising. The light assembly comprises a plurality of light emitting diodes; a printed circuit board connected to the plurality of light emitting diodes and configured to be coupled to a power supply; a presentation board including a plurality of holes, wherein the presentation board overlays and is positioned adjacent the printed circuit board, and the plurality of light emitting diodes extend through the plurality of holes in the presentation board; and a transparent cover covering the plurality of light emitting diodes.

Description

TITLE

LED LIGHTING SYSTEM AND METHOD

FIELD OF THE INVENTION

The present invention relates to lighting. In particular, although not exclusively, the invention relates to lighting comprising light emitting diodes (LEDs).

BACKGROUND TO THE INVENTION

Lighting is a very important feature of a motor vehicle, both to illuminate an area at night, and also to indicate a motorist's intention to other motorists.

Modern motor vehicles typically have a plurality of left and right directional indicator lights and brake lights, in addition to night driving lights. The indicator lights are typically used to indicate a change in direction of travel, and the brake lights are used to indicate a braking of the motor vehicle.

Indicator and brake lights traditionally comprise an incandescent bulb in a coloured casing that forms a lens. The indicator lights typically comprising an orange lens and the brake lights typically comprising a red lens, however in certain countries the indicator light is replaced by a blinking red brake light.

Most countries include standards or rules relating to lights on motor vehicles. In Australia, Australian Standards and Australian Design Rules specify output angles and other features of vehicle lights. In Europe, E- marking applies similar standards to lights on motor vehicles, and most other countries include similar standards.

In order to meet these standards, lights typically include a lens having an etched pattern, which directs light based upon refraction. This can, for example, include directing light to one side of the lens, or focusing light toward a particular area. A problem with such lenses of the prior art is that they are difficult and costly to manufacture. A further problem with indicator and brake lights of the prior art is that they are bulky and prone to damage.

More modern indicator and brake lights incorporate a plurality of light emitting diodes (LEDs) in place of the incandescent bulb(s), which reduces the thickness of the light considerably, however such modern indicator and brake lights are also difficult and costly to manufacture.

Accordingly, there is a need for an improved LED lighting system and method.

OBJECT OF THE INVENTION

It is an object of some embodiments of the present invention to provide consumers with improvements and advantages over the above described prior art, and/or overcome and alleviate one or more of the above described disadvantages of the prior art, and/or provide a useful commercial choice.

SUMMARY OF THE INVENTION

According to one aspect, the invention resides in a light assembly including:

a plurality of light emitting diodes;

a printed circuit board connected to the plurality of light emitting diodes and configured to be coupled to a power supply;

a presentation board including a plurality of holes, wherein the presentation board overlays and is positioned adjacent the printed circuit board, and the plurality of light emitting diodes extend through the plurality of holes in the presentation board; and

a transparent cover covering the plurality of light emitting diodes. Preferably, graphics or text is printed on an outer surface of the presentation board adjacent the plurality of light emitting diodes. Preferably, the printed circuit board comprises a circuitry side, the circuitry side comprising a plurality of electrical tracks, wherein each light emitting diode is connected to an electrical track and extends through the printed circuit board from the circuitry side to an opposite side adjacent the presentation board.

Preferably, the printed circuit board is substantially flat.

Preferably, the printed circuit board is curved.

Preferably, the plurality of light emitting diodes includes at least one light emitting diode configured to direct light in a first direction and at least one light emitting diode configured to direct light in a second direction that is different from the first direction.

Preferably, the plurality of holes in the presentation board extend through the graphics or text, whereby the plurality of light emitting diodes illuminate the graphics or text.

Preferably, the transparent lens comprises an outer cover, adjacent to and covering the presentation board.

Preferably, the outer cover is planar.

Preferably, the outer cover comprises a substantially flat lens, substantially parallel to the presentation board, in a spaced relationship with the light emitting diodes.

Preferably, the outer cover is integrally formed with the light emitting diodes.

Preferably, the light emitting diodes cover less than 50% of the presentation board.

Preferably, the light emitting diodes cover less than 20% of the presentation board.

Preferably, the presentation board comprises a printed surface.

Preferably, the printed surface comprises advertising.

Preferably, the light assembly includes at least one light emitting diode having a lens for directing light towards the printed surface. Preferably, at least one light emitting diode comprises a semiconductor die adjacent a reflective cavity, the reflective cavity configured to direct light in a first direction.

Preferably, the light assembly comprises a tail light assembly for a vehicle.

According to another aspect, the invention resides in a method of manufacturing a light assembly having a predetermined light output pattern, including:

arranging a plurality of light emitting diodes according to the predetermined light output pattern;

connecting the plurality of light emitting diodes to a printed circuit board, the printed circuit board configured to be coupled to a power supply;

positioning a presentation board adjacent the printed circuit board, wherein the plurality of light emitting diodes extend through a plurality of holes in the presentation board; and

providing a protective cover to the light emitting diodes.

Preferably, providing the protective cover comprises attaching a protective cover. Alternatively, providing the protective cover comprises setting the light emitting diodes in resin.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention are described below by way of example only with reference to the accompanying drawings, in which:

FIG. 1a illustrates a front perspective view of a light assembly, according to an embodiment of the present invention;

FIG. 1b illustrates a front view of the light assembly of FIG. 1a; FIG. 1c illustrates a rear view of the light assembly of FIG. 1a;

FIG. 1d illustrates a side view of the light assembly of FIG. 1a; FIG. 2 illustrates a rear cut out view of the light assembly of FIG. 1a, wherein an opaque layer covering electrical tracks and a signal lead is removed;

FIG. 3a illustrates a light emitting diode (LED), configured to direct light upwards;

FIG. 3b illustrates an LED, configured to direct light sideward;

FIG. 4a illustrates a front view of an advertising board, according to an embodiment of the present invention;

FIG. 4b illustrates a perspective view of the advertising board of FIG. 4a;

FIG. 4c illustrates a side view of the advertising board of FIG. 4a;

FIG. 5 illustrates a light assembly, according to an embodiment of the present invention; and

FIG. 6 illustrates a method of manufacturing a light assembly having a predetermined light output pattern.

Those skilled in the art will appreciate that minor deviations from the layout of components as illustrated in the drawings will not detract from the proper functioning of the disclosed embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention comprise LED lighting systems and methods. Elements of the invention are illustrated in concise outline form in the drawings, showing only those specific details that are necessary to the understanding of the embodiments of the present invention, but so as not to clutter the disclosure with excessive detail that will be obvious to those of ordinary skill in the art in light of the present description.

In this patent specification, adjectives such as first and second, left and right, front and back, top and bottom, etc., are used solely to define one element or method step from another element or method step without necessarily requiring a specific relative position or sequence that is described by the adjectives. Words such as "comprises" or "includes" are^{^} not used to define an exclusive set of elements or method steps. Rather, such words merely define a minimum set of elements or method steps included in a particular embodiment of the present invention.

According to one aspect, the invention resides in a light assembly including: a plurality of light emitting diodes; a printed circuit board connected to the plurality of light emitting diodes and configured to be coupled to a power supply; a presentation board including a plurality of holes, wherein the presentation board overlays and is positioned adjacent the printed circuit board, and the plurality of light emitting diodes extend through the plurality of holes in the presentation board; and a transparent cover covering the plurality of light emitting diodes.

Advantages of certain embodiments of the present invention include an ability to manufacture light assemblies of various shapes and configurations without complex machinery and without having to define complex lens moulds. Furthermore, light assemblies according to the present invention can be thinner and stronger than light assemblies of the prior art. Yet a further advantage of certain embodiments of the present invention is that a surface of the light assembly can be used for advertising, without adversely affecting the light assembly.

FIG. 1a illustrates a front perspective view of a light assembly 100, according to an embodiment of the present invention. FIG. 1b illustrates a front view of the light assembly 100, FIG. 1c illustrates a rear view of the light assembly 100 and FIG. 1d illustrates a side view of the light assembly 100.

The light assembly 00 comprises a combined brake, tail, indicator and number plate light suitable for a vehicle or a trailer associated with a vehicle. As will be readily understood by the skilled addressee, the light assembly 100 can be adapted to suit any type of vehicle or machinery including, for example, buses, forklifts and mining equipment.

The light assembly 100 includes a plurality of light emitting diodes (LEDs) 105 comprising a plurality of indicator LEDs 1 0 and a plurality of brake-tail light LEDs 115. The indicator LEDs 110 comprise orange coloured LEDs, and the brake-tail light LEDs 115 comprise red LEDs.

The indicator LEDs 110 can be turned either on or off, and in use typically blink at a rate of 60 to 120 times per minute in a manner controlled by the vehicle. In contrast, the brake-tail light LEDs 115 can be turned on at a partial rate, full rate or off, in a manner controlled by the vehicle. In use, the brake-tail light LEDs 115 are turned on at the partial rate when the tail light of the vehicle is in operation, and at the full rate when brake light of the vehicle is in operation.

According to certain embodiments, the partial rate can comprise approximately 20-25% of the full rate. According to other embodiments, the partial and full rates of the brake-tail light LEDs 115 correspond to a 5 and 21 watt output respectively of a dual filament incandescent 5/21W bulb such as part number is 7528 by Osram AG of Munich, Germany.

The indicator LEDs 110 comprise a first plurality of indicator LEDs

110a configured to direct light in a first direction 120 and a second plurality of indicator LEDs 110b configured to direct light in a second direction 125. This enables the indicator LEDs 110 to be visible both from a rear of the light assembly 100 and a side of the light assembly 100.

The brake-tail light LEDs 115 comprise a first plurality of brake-tail light LEDs 115a configured to direct light in the first direction 120, a second plurality of brake-tail light LEDs 110b configured to direct light in the second direction 125 and a third plurality of brake-tail light LEDs 110c configured to direct light in a third direction 130. This enables the brake- tail light LEDs 110 to be visible from the rear of the light assembly 100 and from both sides of the light assembly 100.

Having LEDs 105 that direct light in several directions enables a suitable pattern of light to be emitted from the light assembly 100 without requiring a specific lens to direct or diffuse the light.

The light assembly 100 comprises a printed circuit board (described in further detail below) having a presentation side 135 and a circuitry side 140. The indicator LEDs 110 and the brake-tail light LEDs 115 protrude from the presentation side 135 of the printed circuit board.

The circuitry side 140 comprises a plurality of electrical components 145, including resistors, diodes and other components, and electrical tracks (not shown) for connecting the plurality of LEDs 105. The indicator LEDs 110 and the brake-tail light LEDs 115 extend through the printed circuit board from the electrical tracks of the circuitry side 140 to the presentation side 135.

The circuitry side 140 comprises a thin cover opaque layer covering the electrical tracks, which electrical tracks are described further below.

The plurality of electrical components 145 together with the tracks, enable the light assembly 100 to function when provided with one or more 2v signals through a signal lead 150 comprising a plurality of signal wires 155. The plurality of signal wires include a break light signal wire, an indicator signal wire, a running light signal wire, a number plate light signal wire, and a ground wire.

According to certain embodiments, a signal voltage on the signal lead 150 is variable. In particular, the signal voltage can vary between 12v and. 33v. However, as will be readily understood by the skilled addressee, the electrical components 145 and/or the light assembly 100 can be adapted to receive any suitable signal voltage.

In the case of a trailer, the signal lead 150 can, for example, be connected to a 7-pin trailer plug. In the case of a vehicle, the signal lead 150 can be connected to signalling components of the vehicle, such that power is supplied to the signal lead 150 when a relevant action, such as braking, is performed in the vehicle. However, as will be understood by the skilled addressee, the signal lead 150 can be connected to any suitable power supply.

Each LED 105 is connected to an electrical track by a solder point 160. As will be readily understood by the skilled addressee, the opaque layer covering the electrical tracks can comprise a solder map (not shown) which enables an assembler of the light assembly 100 to solder the electrical components 145 and LEDs 105, without seeing the electrical tracks. In this case, indicia on the solder map are used to identify soldering locations, such indicia ultimately melting away when the actual soldering takes place.

As discussed above, the brake-tail light LEDs 115 are able to operate at partial and full rates. Partial rate is achieved when only the running light signal wire is active, and full rate is achieved when the brake light signal wire is active.

The light assembly 100 further comprises a plurality of number plate LEDs 165, connected to the electrical tracks, and on the circuitry side 140. The number plate LEDs 165 are directed upwards with reference to the light assembly 100, in order to illuminate a number plate located above the light assembly 100. However, as will be understood by the skilled addressee, the number plate LEDs 165 can be directed to a side or below the light assembly 100 in order to illuminate a number plate located beside or below the light assembly 100.

Finally, the light assembly 100 comprises an outer cover 170, adjacent to and covering the presentation side 135, including a reflective element 175. The outer cover 170 is substantially transparent, flat and parallel to the presentation side 135, thus allowing light from the LEDs 105 to pass through substantially unchanged.

The outer cover 170 is in a spaced relationship with the LEDs 105, thus protecting the LEDs 105 from damage in case pressure is applied to the outer cover 170.

According to an alternative embodiment (not shown), the outer cover is integrally formed with the LEDs 105. In this case, the outer cover can comprise a solid resin cover, in which the LEDs 105 and potentially other components are formed.

By using LEDs 105 that direct light in different directions, it is possible to manufacture the light assembly with a simplistic outer cover/lens, while maintaining complex light patterns as required by design rules and standards. FIG. 2 illustrates a rear cut out view of the light assembly 100, wherein the opaque layer covering electrical tracks and the signal lead 150 is removed.

The light assembly 100 includes a plurality of electrical tracks 205, defining circuitry connecting the plurality of light emitting diodes 105 and configured to be coupled to a power supply.

The indicator LEDs 110 and the brake-tail light LEDs 115 are arranged in several groups 210 of four LEDs 105, each group 2 0 coupled in parallel and each LED 105 in the group 210 coupled in series. This, together with the electrical components 145 such as resistors, ensures that each LED 105 operates at or near its nominal voltage. Also, by having relatively short strings of LEDs 105 in series, a malfunction of one LED 105 will only affect three others.

FIG. 3a illustrates a LED 300a, configured to direct light upwards, and FIG. 3b illustrates an LED 300b, configured to direct light sideward.

The LEDs 300a, 300b comprise an anode 305 and a cathode 310, for connecting to a source of direct current, for example by the tracks of a printed circuit board of the light assembly 100. The anode 305 and cathode 310 extend into an epoxy lens 315, which protects the LED 300a, 300b. The epoxy lens 315 can be clear or coloured, depending on the desired colour output.

A wire bond 320 connects the anode 305 and a semiconductor die (not visible) of the cathode 310. Upon application of a voltage across the anode 305 and cathode 310 and hence a flow of current through the LED 300a, 300b, light is emitted from the semiconductor die, which is directed by a reflective cup 325.

The reflective cup 325 of the LED 300a is arranged such that light is directed in a first direction 330a, i.e. substantially upwards, whereas the reflective cup 325 of the LED 300b is arranged such that light is directed in a second direction 330b, i.e. in a sideward direction.

By arranging the reflective cup 325 in a particular manner, light can be directed without substantially modifying other components of the LED 300a, 300b. However, according to alternative embodiments, one or more of the epoxy lens 315, the anode 305 and the cathode 310 can be modified according to the direction of the reflective cup 325.

According to alternative embodiments, an LED 300a, 300b is directed by bending lower portions of the anode 305 and cathode 310, such that the epoxy lens 315, and all components contained therein (including the reflective cup 325) are directed in a desired direction.

According to yet further alternative embodiments, the epoxy lens 315 comprises a grating (not shown) for directing light. The grating directs light by means of diffraction.

According to yet further embodiments, mirrors or other reflective devices can be associated with each LED 300a, 300b.

FIG. 4a illustrates a front view of a presentation board in the form of an advertising board 400, according to an embodiment of the present invention. FIG. 4b illustrates a perspective view of the advertising board 400 and FIG. 4c illustrates a side view of the advertising board 400.

The advertising board 400 is substantially flat and comprises a presentation side 405 and a backing side 410. The advertising board 400 includes indicia in the form of advertising 420, printed on a surface of the presentation side 420, and a plurality of apertures 415, for enabling LEDs to extend through the advertising board.

As such, the advertising board 400 can be placed over a circuit board including light diodes, such as over the presentation side 135 of the light assembly 100 of FIG. 1 , prior to assembly of the outer cover 170 and reflective lens 175.

Various different advertising boards 400 can be inexpensively manufactured, and a suitable advertising board 400 can be selected at a late stage of manufacture.

FIG. 5 illustrates a light assembly 500, according to an embodiment of the present invention. The light assembly 500 is similar to the light assembly 100 of FIG. 1 , but with more LEDs 105 in place of the reflective element 175. The light assembly 500 comprises a plurality of LEDs 105, adjacent a presentation side 535 similar to the presentation side 135 of FIG. 1. The presentation side 535, however, includes indicia in the form of advertising 505, printed on a surface of the presentation side 535. The advertising can comprise a logo, image, text or any other suitable advertising.

According to certain embodiments, the LEDs 105 comprise a first plurality of LEDs 105, directly associated with the advertising, and configured to direct light onto the advertising. A second plurality of LEDs 105 can then be configured to direct light in another direction, e.g. outwards, such as enabling a brake or warning light.

The advertising 505 can, for example, comprise a metallic or reflective paint or print, or fluorescent paint, which is configured to glow when placed under ultraviolet light. In this latter case, one or more of the first plurality of LEDs 105 can comprise ultraviolet or near ultraviolet LEDs, while the second plurality of LEDs 105 are in the visible spectrum. As discussed above, the second plurality of LEDs 105 can comprise brake or signalling LEDs.

According to certain embodiments, the LEDs 105 cover less than 50% of a presentation surface of the light assembly 500. However, more suitably, the light emitting diodes cover less than 20% of the presentation surface, as eac LED 105 can obscure a small portion of the advertising 505.

As will be readily understood by the skilled addressee, the first plurality of LEDs 105 can operate in a mutually exclusive manner to the second plurality of LEDs 105. As an illustrative example, no advertising is shown or enhanced when the light assembly 500 shows signalling such as an indicator or brake light, but shows advertising otherwise.

FIG. 6 illustrates a method 600 of manufacturing a light assembly having a predetermined light output pattern.

In step 605, a plurality of LEDs are arranged according to a predetermined light output pattern. The LEDs can, for example, be arranged on a printed circuit board, such that the predetermined light output pattern is achieved by the positions of the LEDs on the printed circuit board.

In step 610, the plurality of light emitting diodes are connected to a printed circuit board, the printed circuit board configured to be coupled to a power supply.

In step 615, a presentation board is positioned adjacent the printed circuit board, wherein the plurality of light emitting diodes extend through a plurality of holes in the presentation board.

In step 620, a protective cover is provided to the light emitting diodes. Providing the protective cover can comprise attaching a protective cover to the light assembly, such that the protective cover and LEDs are in a spaced relationship. A spacing between the LEDs and the protective cover can help protect the LEDs if the protective cover flexes under pressure.

Alternatively, providing the protective cover comprises setting the

LEDs in resin. By setting the LEDs in resin, a solid light assembly can be made. In this case, the light assembly can be very thin as the resin need only minimally extend above the LEDs or just below a top of the LEDs.

The predetermined light output pattern is defined by the plurality of light emitting diodes, thus the protective cover need not have any etchings or otherwise to generate the light pattern.

According to the embodiments described above, the printed circuit boards and light assemblies are substantially flat. As will be readily understood by the skilled addressee, the printed circuit board and light assemblies can be curved or otherwise formed to suit a contour of a vehicle or other product.

Similarly, the cover described in the above embodiments can be transparent and smooth, i.e. does not include any etchings or otherwise to direct or diffuse the light. However, as will be readily understood by the skilled addressee, the cover can be tinted, and include certain markings. However, directionality of the light may be advantageously defined primarily by the light emitting diodes. As the cover is relatively simple, e.g. does not include etchings to direct or diffuse the light, it is relatively quick and easy to make one-off and customised lights. This can be achieved by placing light emitting diodes on a circuit board having a desired shape, and manufacturing a simple cover to suit.

In summary, advantages of some embodiments of the present invention include an ability to manufacture light assemblies of various shape and configuration without complex machinery and without having to define complex lens moulds. Furthermore, light assemblies according to the present invention can be thinner and stronger than light assemblies of the prior art. Yet a further advantage of certain embodiments of the present invention is a surface of the light assembly can be used for advertising, without adversely affecting the light assembly.

The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this patent specification is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

The claims defining the invention are:

1. A light assembly including:

a plurality of light emitting diodes;

a transparent cover covering the plurality of light emitting diodes.

2. The light assembly of claim 1 , wherein graphics or text is printed on an outer surface of the presentation board adjacent the plurality of light emitting diodes.

3. The light assembly of claim 1 , wherein the printed circuit board comprises a circuitry side, the circuitry side comprising a plurality of electrical tracks, wherein each light emitting diode is connected to an electrical track and extends through the printed circuit board from the circuitry side to an opposite side adjacent the presentation board.

4. The light assembly of claim 1 , wherein the printed circuit board is substantially flat.

5. The light assembly of claim 1 , wherein the printed circuit board is curved.

6. The light assembly of claim 1 , wherein the plurality of light emitting diodes includes at least one light emitting diode configured to direct light in a first direction and at least one light emitting diode configured to direct light in a second direction that is different from the first direction

7. The light assembly of claim 2, wherein the plurality of holes in the presentation board extend through the graphics or text, whereby the plurality of light emitting diodes illuminate the graphics or text.

8. The light assembly of claim i, wherein the transparent lens comprises an outer cover, adjacent to and covering the presentation board.

9. The light assembly of claim 8, wherein the outer cover is planar.

10. The light assembly of claim 8, wherein the outer cover comprises a substantially flat lens, substantially parallel to the presentation board, in a spaced relationship with the light emitting diodes.

11. The light assembly of claim 8, wherein the outer cover is integrally formed with the light emitting diodes.

12. The light assembly of claim 1 , wherein the light emitting diodes cover less than 50% of the presentation board.

13. The light assembly of claim 12, wherein the light emitting diodes cover less than 20% of the presentation board.

14. The light assembly of claim 1 , wherein the presentation board comprises a printed surface.

15. The light assembly of claim 14, wherein the printed surface comprises advertising.

16. The light assembly of claim 14, wherein the light assembly includes at least one light emitting diode having a lens for directing light towards the printed surface.

17. The light assembly of claim 1 , wherein at least one light emitting diode comprises a semiconductor die adjacent a reflective cavity, the reflective cavity configured to direct light in a first direction.

18. The light assembly of claim 1 , wherein the light assembly comprises a tail light assembly for a vehicle.

19. A method of manufacturing a light assembly having a predetermined light output pattern, including:

providing a protective cover to the light emitting diodes.

20. The method of claim 19, wherein providing the protective cover comprises setting the light emitting diodes in resin.