AU2006100304A4 - Light emitting diode based light - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Applicant: Ningbo Ledeshi Electric Equipment Co., Ltd Invention Title: LIGHT EMITTING DIODE BASED LIGHT The following statement is a full description of this invention, including the best method of performing it known to us: 1 Light Emitting Diode Based Light Field of the Invention The present invention relates generally to domestic and commercial lighting and, more particularly, to light emitting diode based lights.

Background of the Invention Conventional filament light bulbs are used in domestic and commercial buildings as a source of light. Although inexpensive to buy and readily available, filament light bulbs have relatively short lifetimes and can consume a significant amount of power.

Summary of the Invention According to a first aspect of the present invention there is provided a light emitting diode based light comprising: at least one light emitting diode; and a first electrical connector which is electrically connected to the at least one light emitting diode, wherein the first electrical connector is arranged to be coupled to a second electrical connector to allow a current to flow through the at least one light emitting diode.

Preferably, the first electrical connector comprises a pair of spaced apart metal lugs that are arranged to be received by the second electrical connector to secure the at least one light emitting diode thereto.

Preferably, the light emitting diode based light comprises a plurality of light emitting diodes and the light emitting diodes are arranged in a circular pattern over a first surface of the body.

Preferably, the light emitting diode based light further comprises a translucent plastic cover which encases the at least one light emitting diode.

Preferably, the translucent plastic cover comprises at least one part arranged to diffuse light emitted from the at least one light emitting diode.

-3- According to a second aspect there is provided a light emitting diode based light comprising: at least one light emitting diode located in a cavity; and a first electrical connector which is electrically connected to the at least one light emitting diode, wherein the first electrical connector is arranged to be coupled to a second electrical connector to allow a current to flow through the at least one light emitting diode.

Preferably, the first electrical connector comprises a screw thread that is attached to a cathode terminal of the at least one light emitting diode and an electrically isolated bump point which is attached to an anode terminal of the at least one light emitting diode and wherein the second electrical connector comprises a receiving screw thread and end-piece attached to terminals of a power source.

Preferably, the cavity is generally hemispherical.

Preferably, the light emitting diode based light further includes at least one vent facilitating air flow.

Preferably, the cavity has a reflective surface for reflecting light.

Preferably, the light emitting diode based light further comprises a control circuit which is electrically connected between the at least one light emitting diode and first electrical connector and which comprises a conversion means for converting an alternating current input received at the first electrical connector to a direct current output for supply to the at least one light emitting diode. In this manner the light emitting diode based light can be .fitted into conventional filament light bulb sockets and fittings. The control circuit may also provide componentry for enhanced light emitting diode control such as brightness, colour change, timing and the like. The control circuit may also incorporate wireless circuitry to allow the light emitting diode based light to be controlled remotely.

Advantageously, and in accordance with embodiments of the present invention, the light emitting diode based light can be used as a replacement lighting source for conventional filament bulbs, requires less power than conventional filament bulbs and which provides longer operational lifetimes.

-4- Brief Description of the Drawings Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figures 1 a, b c show a top, side and front view, respectively, of a light emitting diode based light according to a first embodiment of the present invention; Figure ld is a top view of a socket for retaining the light emitting diode based light according to the first embodiment; Figure le is a printed circuit board track layout of the light emitting diode based light according to the first embodiment; Figures 2a and 2c show a front and bottom view, respectively, of a light emitting diode based light according to a second embodiment of the present invention; Figure 2b is a cross sectional view of Figure 2a; and Figure 2e is a perspective view of a socket for retaining the light emitting diode based light of the second embodiment.

An Embodiment of the Invention Referring to Figures la to Ic, there is shown a light emitting diode based light according to a first embodiment of the present invention. The light emitting diode based light 10 comprises a body in the form of a plastic moulded disc 12, and a plurality of light emitting diodes 14. The plurality of light emitting diodes 14 are electrically connected together in series by way of conductive tracks 13 which are etched on a printed circuit board 16 (see Figure le) encased within the plastic moulded disc 12. The light emitting diodes 14 are mounted to a first face 15 of the plastic moulded disc 12 in a circular pattern by epoxy glue. The light emitting diode based light 10 further comprises a first electrical connector in the form of spaced apart brass lugs 18. The brass lugs 18 are mounted to, and extend rearwardly from, a second face 20 of the plastic moulded disc 12. The brass lugs 18 are wired to one of a positive and negative terminal 17, 19 which are provided on the printed circuit board 16 and which connect to the conductive tracks 13. The brass lugs 18 have enlarged end pieces 24, 26 that may be received in first cavities 28, 30 defined in a first face 32 of a second electrical connector in the form of a socket 22 (see Figure d).

To secure the light emitting diode based light 10 to the socket 22, the plastic moulded disc 12 is inserted and rotated in a clockwise direction so that the enlarged end pieces 24, 26 of the brass lugs 18 move toward second cavities 34, 36 which are also defined in the first face 32 of the socket 22 and which have outer diameters that are narrower than those of the enlarged end pieces 24, 26. The second cavities 34, 36 also comprise electrical contacts 38, 40 which are spring loaded to engage the enlarged end pieces 24, 26 once the plastic moulded disc 12 has been rotated into position. The electrical contacts 38, 40 are wired in series to an AC/DC converter (not shown) for converting a supplied AC current to a DC current suitable for input to the light emitting diode based light The light emitting diode based light 10 further comprises a translucent casing in the form of a plastic cover 42 which is removably attached to the plastic moulded disc 12 by retaining screws 44. The plastic cover 42 has a grooved upper surface 45 for diffusing light emitted by the encased light emitting diodes 14. -The plastic cover 42 may be formed of different coloured plastics depending on the desired lighting effect.

The plastic cover 42 may act as a lens for focussing emitted light.

The light emitting diodes 14 are arranged in a circular pattern over the first face 15 of the circular plastic disc 12 so as to provide a uniform distribution of emitted light. In practice, however, the grouping and number of light emitting diodes 14 will depend only on the desired brightness, output, shape, size and intended application of the light emitting diode based light 10. For example, the body may be moulded in a square shape so as to fit unobtrusively within a square tiled warehouse ceiling and may comprise of twenty five super bright light emitting diodes arranged uniformly over the body's emitting surface for outputting a concentrated bright light.

In the above described embodiment, the light emitting diode based light 10 is arranged to receive a DC voltage which is suitable for direct input to the light emitting diodes 14. However, it is also envisaged that the light emitting diode based light could be arranged to receive power from an AC input. For AC operation an AC/ DC conversion means, such as a full wave diode rectifier, is connected to the printed circuit board 16 to convert the input AC input to a low voltage DC output before it is passed to the light emitting diodes 14. The printed circuit board 16 may also incorporate circuitry to impede the current supplied to the light emitting diodes 14 to achieve a desired brightness. It should also be readily understood that the substrate 16 may include other forms of electrical and electronic circuitry for a desired operation of the light emitting diodes 14, including, but not limited to, dimmers, flashers, timers etc.

A second embodiment of the present invention will now be described with reference to Figs. 2a, 2b, 2c. According to the second embodiment the light emitting diode based light 100 comprises a body 102 which made of a heat resilient plastic and having a generally hemispherical end-piece 104 extending from a cylindrical portion 106. Mounted within a cavity 108 defined at an outer end 110 of the hemispherical end-piece 104 is a single light emitting diode 112 for emitting light. The cavity 108 is lined with a reflective coating 109 for reflecting light out of the cavity 108. The light emitting diode based light 100 further comprises a first electrical connector 118 in the form of a metallic screw thread 120 and bump point 122. The first electrical connector 118 is crimped to, and extends away from, the cylindrical portion 106 of the body 102.

The bump point 122 is electrically isolated from the screw thread 120 by a ceramic insulator 124. Wires 130, 132 connect the cathode and anode terminals 126, 128 of the light emitting diode 112 to the screw thread 120 and bump point 122, respectively. The screw thread 120 and bump point 122 are received by a second electrical connector in the form of a socket 134 having a receiving thread 136 and base 138, as illustrated in figure 2d.

Also in accordance with the second embodiment, the light emitting diode based light 100 comprises a control circuit 140 which is located at an inner cavity 141 defined within the body 110 and which is electrically connected in series between the wires 130, 132 and the terminals 126, 128 of the light emitting diode 112. The control circuit 140 comprises an AC/ DC conversion means in the form of a full wave rectifier and a step down circuit which is arranged to convert an input alternating current (eg a 240V AC supplied to the socket) to a low voltage direct current output for supply to the light emitting diode 112.

Although the above described embodiment relates to a screw thread connector, it is envisaged that the first and second electrical connectors could also be of a bayonet configuration. In one embodiment the hemispherical end-piece 104 comprises a plurality of vents 142 for allowing air to pass in and out of the cavity 108.

The light emitting diode(s), according to either of the first or second embodiments, may comprise of different colours and output brightness for improving -7the variety and style of lighting. The substrate or control circuit may further comprise a switching means to vary the emitted light colour when used in connection with variablecolour light emitting diodes. The control circuit 140 may include IC componentry for effecting blinking, dimming, timing etc of the light emitting diode(s).

Although the above described embodiments related to light emitting diode based lights for illuminating home and office workspaces, it should be understood that they are by no means limited to these applications. It is envisaged that the light emitting diode based lights may also be suitable for traffic lights, car lights, desk lights, warning lights and the like.

According to embodiments of the present invention there are provided light emitting diode based lights that may outlast conventional filament light bulbs and which may also provide drastically improved power savings. The light emitting diode based lights can be fitted into existing light bulb sockets as replacement alternative lighting as well as being arranged to provide enhanced features such as automated colour change, dimming and remote operation.

Any reference to the prior art contained herein is not to be taken as an admission that the information is common general knowledge, unless otherwise indicated.

In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Finally, it is to be understood that various alterations or additions may be made to the parts previously described without departing from the spirit or ambit of the present invention.

Claims (12)

1. A light emitting diode based light comprising: at least one light emitting diode; and a first electrical connector which is electrically connected to the at least one light emitting diode, wherein the first electrical connector is arranged to be coupled to a second electrical connector to allow a current to flow through the at least one light emitting diode.

2. A light emitting diode based light as claimed in claim 1, wherein the first electrical connector comprises a pair of spaced apart metal lugs that are arranged to be received by the second electrical connector to secure the at least one light emitting diode thereto.

3. A light emitting diode based light as claimed in any one of the preceding claims, wherein the light emitting diode based light comprises a plurality of light emitting diodes and the light emitting diodes are arranged in a circular pattern over a first surface of the body.

4. A light emitting diode based light as claimed in any one of the preceding claims, further comprising a translucent plastic cover which encases the at least one light emitting diode.

A light emitting diode based light as claimed in claim 4, wherein the translucent plastic cover comprises at least one part arranged to diffuse light emitted from the at least one light emitting diode.

6. A light emitting diode based light comprising: at least one light emitting diode located in a cavity; and a first electrical connector which is electrically connected to the at least one light emitting diode, wherein the first electrical connector is arranged to be coupled to a second electrical connector to allow a current to flow through the at least one light emitting diode.

7. A light emitting diode based light as claimed in claim 6, wherein the first electrical connector comprises a screw thread that is attached to a cathode terminal of the at least one light emitting diode and an electrically isolated bump point which is attached to an anode terminal of the at least one light emitting diode and wherein the second electrical connector comprises a receiving screw thread and end piece attached to terminals of a power source.

8. A light emitting diode based light as claimed in any one of claims 6 or 7, wherein the cavity is generally hemispherical.

9. A light emitting diode based light as claimed in any one of claims 6 to 8, further including at least one vent facilitating air flow.

A light emitting diode based light as claimed in any one of claims 6 to 9, wherein the cavity has a reflective surface for reflecting light.

11. A light emitting diode based light as claimed in any one of claims 6 to further comprising a control circuit which is electrically connected between the at least one light emitting diode and first electrical connector and which comprises a conversion means for converting an AC voltage received at the first electrical connector to a DC voltage for supply to the at least one light emitting diode.

12. A light emitting diode based light substantially as herein before described with reference to the accompanying drawings. Dated this 17th day of April 2006 NINGBO LEDESHI ELECTRIC EQUIPMENT CO.. LTD By its Patent Attorneys GRIFFITH HACK