WO2010030336A1

WO2010030336A1 - Hybrid light bulbs

Info

Publication number: WO2010030336A1
Application number: PCT/US2009/005031
Authority: WO
Inventors: Carol Lenk
Original assignee: Superbulbs, Inc.
Priority date: 2008-09-15
Filing date: 2009-09-08
Publication date: 2010-03-18

Abstract

A hybrid light bulb that is more efficient than traditional incandescent bulbs, and more particularly, to the use of both an incandescent filament and an LED to produce acceptable quality light at a low cost.

Description

HYBRID LIGHT BULBS

FIELD OF THE INVENTION

[0001] The present invention relates to light bulbs that are more efficient than traditional incandescent bulbs, and more particularly, to the use of both an incandescent filament and an LED to produce acceptable quality light at a low cost.

BACKGROUND OF THE INVENTION

[0002] A traditional incandescent light bulb has low efficacy, i.e., a small number of lumens of light output for a large amount of input power. For this reason, many governments worldwide are restricting or banning the use of these types of bulbs. In particular, the United States' government will require that by 2014, all light bulbs should have efficacy at least 30% higher than traditional incandescent bulbs. [0003] However, the alternatives presently available have some serious limitations. Today's most common alternative is the compact fluorescent (CFL). This type of bulb has much higher efficacy than does a traditional incandescent light bulb, easily meeting United States' government requirements. However, it has a non-traditional shape, typically has poor light color and quality, contains the toxic heavy metal mercury, and is substantially more expensive than the traditional incandescent bulb. [0004] The other alternative to a traditional incandescent bulb now emerging is an LED bulb. The LED bulb can have even higher efficacy than a CFL, as well as having a traditional shape, excellent light color and quality, and contains no toxic materials. Unfortunately, the LED bulb is still in its infancy, as are LEDs, and consequently LED bulbs are presently, and for the near-term future, even more expensive than are CFLs.

[0005] In many circumstances, it would thus be desirable to have a bulb that had higher efficiency than a traditional incandescent bulb, and in particular meets the US government requirements for 2014. It would also be desirable for a bulb to have a traditional shape, have light color and quality similar to that of a traditional incandescent bulb, contain no toxic materials, and most importantly, be competitively priced with traditional incandescent bulbs.

SUMMARY OF THE INVENTION [0006] This invention has the object of developing a hybrid light bulb that provides the same shape, light output and safety as a traditional incandescent bulb, while achieving higher efficacy at not substantially more cost. In accordance with an exemplary embodiment, the light bulb includes an incandescent filament inside a sealed glass tube, and one or more LEDs in the base of the bulb. In accordance with an embodiment, the one or more LEDs and an optional power converter are preferably heat sunk in the base. The one or more LEDs can also have a diffuser to spread out their light.

[0007] hi accordance with one embodiment, an incandescent filament is enclosed in a partially evacuated bulb-shaped glass enclosure, with power wires coming out through the enclosure. The enclosure is attached to a screw base through conventional methods such as an adhesive, and the power wires are attached to the screw base for energization. The screw base contains one or more LEDs, which in a preferred embodiment are also directly powered from the screw base without a converter. [0008] In accordance with another embodiment, the screw base contains a potting material, which acts as a heatsink for the one or more LEDs, conducting their waste heat out through the screw base. In accordance with an embodiment, the glass enclosure may be attached to the screw base by being partially inserted in the potting compound. [0009] In accordance with another embodiment, the one or more LEDs may be powered from a converter, which is energized from the screw base, and is also mounted inside the potting compound in the screw base, the potting compound acting as a heatsink for the waste heat generated by the converter. [0010] In accordance with another embodiment, the one or more LEDs may have a diffuser attached to them, for example with a fluid, a plastic or a gel, causing the light output from the one or more LEDs to have an angular dispersion similar to that of the incandescent filament. [0011] In all of these embodiments, the efficacy of the bulb can be adjusted to meet requirements by adjusting the balance of power dissipated in the one or more LEDs and the power dissipated in the incandescent filament. For example, the light output from a present-day 6OW soft-white incandescent bulb is 830 lumens, so that its efficacy is 830Lu / 6OW = 13.8Lu/W. In order to meet the new US regulations, this number needs to be increased by 30% to 18.0Lu/W. For 830 lumens, this requires the total bulb wattage not to exceed 46.2W. [0012] To a first order approximation, in which incandescent efficacy is independent of power, and assuming that LEDs' efficacy is 601u/W, these bulb parameters can be accomplished by using 42W of incandescent power and 4.2W of LED power. Total wattage is 46.2W, as required; and light output is 42W * 13.8Lu/W + 4.2W * 60Lu/w = 832 lumens, as required. Thus efficacy has been increased with minimal cost impact, while maintaining the same shape, safety and to a good approximation the same light color and quality as a traditional incandescent bulb.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,

[0014] FIG. 1 is a cross-sectional view of a hybrid light bulb that utilizes both an incandescent filament and an LED. [0015] FIG. 2 is a cross-sectional view of the base of a hybrid light bulb, showing the interface between the source of power, the LED and the filament.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. [0017] According to the design characteristics, a detailed description of the current practice and preferred embodiments is given below.

[0018] FIG. 1 is a cross-sectional view of a hybrid light bulb 10 that utilizes both an incandescent filament 30 and one or more LEDs 40 (e.g., LED 40). As shown in FIG. 1, the light bulb 10 includes a sealed, partially evacuated glass tube 20 and a screw-in base 50. The screw-in base 50 includes a series of screw threads 52 and a base pin 54. In accordance with an exemplary embodiment, the screw-in base 50 is configured to fit within and make electrical contact with a standard electrical socket 110 (FIG. 2). The electrical socket is preferably dimensioned to receive an incandescent or other standard light bulb as known in the art. However, it can be appreciated that the screw-in base 50 can be modified to fit within any electrical socket which is configured to receive a light bulb, such as a bayonet style base. The screw-in base 50 makes electrical contact with a source of power (e.g., AC power) in a socket through its screw threads 52 and its base pin 54. [0019] As shown in FIG. 1, the sealed, partially evacuated glass tube 20 contains within it an incandescent filament 30. In accordance with an embodiment, the tube 20 can be partially filled with a gas 22. The filament 30 exits the sealed, partially evacuated glass tube 20 through a pair of hermetically sealed exits (not shown). The filament 30 is connected to the screw-in base 50, providing it with AC power. In accordance with an exemplary embodiment, the light bulb 10 also includes one or more LEDs 40, which are contained within or attached to the screw-in base 50. The one or more LEDs 40 are preferentially of the type that may be directly powered by AC. For example, as shown in FIG. 1, the LED 40 can be connected to the screw-in base 50, which provides the LED 40 with a source of power (i.e., AC power). It can also be appreciated that the incandescent filament 30 can be replaced with other suitable light elements.

[0020] FIG. 2 is a cross-sectional view of the base 50 of a hybrid light bulb, showing the interface between the source of power, the LED 40 and the filament 30. As shown in FIG. 2, both the LED 40 and the filament 30 are preferentially directly connected to the screw-in base 50 to receive AC power. The screw-in base 50 may include a potting compound 80, which acts as a heatsink for the LED 40 to the screw-in base 50. In accordance with another embodiment, the one or more LEDs 40 may be powered from a ballast 100, which is energized from the screw base 50, and is also mounted inside the potting compound 80 in the screw base 50, and wherein the potting compound 80 acts as a heatsink for the waste heat generated by the converter 100. [0021] In accordance with another embodiment, a diffuser 90 can be attached to the LED 40, which spreads the light from the LED 40 through a greater angle than can be achieved by the LED 40 alone. For example, the diffuser 90 can be a fluid, a plastic or a gel, which causes the light output from the one or more LEDs 40 to have an angular dispersion similar to that of the incandescent filament. In accordance with an exemplary embodiment, the diffuser 90 is a gel or gel-like material.

[0022] It will be apparent to those skilled in the art that various modifications and variation can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.

Claims

What is claimed is:

1. A hybrid light bulb comprising: a sealed tube having an incandescent filament therein; one or more LEDs; and a base configured to be received within an electrical socket.

2. A hybrid light bulb as set forth in Claim 1, wherein the tube is partially evacuated.

3. A hybrid light bulb as set forth in Claim 2, wherein the tube is partially filled with a gas.

4. A hybrid light bulb as set forth in Claim 1, wherein the incandescent filament exits the sealed tube through a hermetic seal.

5. A hybrid light bulb as set forth in Claim 1, wherein the one or more LEDs are located outside said sealed tube.

6. A hybrid light bulb as set forth in Claim 5, wherein the one or more

LEDs are located in the base.

7. A hybrid light bulb as set forth in Claim 6, wherein the LEDs are potted in the base.

8. A hybrid light bulb as set forth in Claim 5, wherein the one or more LEDs are located adjacent to a base.

9. A hybrid light bulb as set forth in Claim 1, wherein the one or more LEDs have a diffuser adjacent to the one or more LEDs to widen the emission angle of light.

10. A hybrid light bulb as set forth in Claim 9, wherein the diffuser is a gel.

11. A hybrid light bulb as set forth in Claim 1 , wherein the incandescent filament is powered directly from power being applied to the base through an electrical socket.

12. A hybrid light bulb as set forth in Claim 1, wherein the one or more LEDs are powered directly from power being applied to the base through an electrical socket.

13. A hybrid light bulb as set forth in Claim 1, wherein the one or more LEDs are powered by a ballast in the base.

14. A hybrid light bulb as set forth in Claim 1, wherein the incandescent filament and the one or more LEDs are both powered at the same time.

15. A hybrid light bulb as set forth in Claim 1, wherein the base is a screw-in base.

16. A hybrid light bulb comprising: a sealed tube having a fluorescent column therein; a ballast configured to run the fluorescent column; one or more LEDs; and a base configured to fit within an electrical socket.