Patent Application
20150192284
The present invention relates generally to lighting devices, and in particular to a light-emitting diode light bulb with separable LED lamp and power supply portions.
Present LED light bulbs have several limitations and critical design requirements:
1) the LEDs must be kept cool to assure adequate lifetime. Effective heat sinking is critical.
2) bulb life must be very long to provide a good value for the consumer. The reliability of the power electronics is critical for long bulb life because power electronics is often the cause of bulb failure.
3) present bulbs only offer fixed colors (e.g. different color temperatures or colors).
4) failure in only the power electronics, or only the LED lamps cannot be easily tested by the consumer. Hence, repairable lamps are discarded.
5) improvements in LED technology are available only by buying completely new bulbs.
6) the edison bulb shape tends to minimize surface area (i.e. is a low surface area to volume ratio shape), increasing difficulty of adequate heat dissipation in warm environments.
7) LED lamps cannot have long heat sink fins or fingers on the outer surface of the lamp, because they will interfere with fixtures, become tangled, and can be broken or apply excessive force to the LED lamps or LED circuitboard. For these reasons, LED lamps typically have smooth, low-profile heat sinks on the outer surface, which limits heat dissipation, and adversely effects LED lamp life.
Accordingly, there is a need for an LED light bulb with improved heat dissipation and modular construction that allows a consumer to replace only the LED portion or only the power electronics portion. Also, there is a need for an LED light bulb that allows a consumer to select a desired color or color temperature.
The present invention provides an LED light bulb with a top portion and a bottom portion. The top portion contains LED lamps and a connector for connecting to the bottom portion. The bottom portion contains power supply electronics. The top portion and bottom portion are separated by a gap through which air can flow. Preferably, the gap is open along an entire circumference of the gap. The top portion also comprises a heat sink in thermal contact with the LED lamps. The heat sink can have fins, fingers or other features that extend into the gap.
Optionally, the top portion and bottom portion are detachable.
A vent hole can be present in the top portion or the bottom portion. The vent hole is fluidically connected to the gap and allows convective air flow when the light bulb is oriented vertically.
The gap can be about ¼-¾″ wide for example.
In a preferred embodiment, the top portion containing the LED lamps has a male connector (e.g. pins or plugs) that extends across the gap.
Also, there can be multiple ways of connecting the top portion and bottom portion, with each way providing a different type of light output.
The present invention provides a light emitting diode (LED) light bulb having a separable top portion containing LED lamps, and a bottom portion containing power supply electronics. A gap is present between the top portion and bottom portion. The top and bottom can optionally be completely separated, which allows users to swap different LED lamps and power supply electronics. A heat sink element is disposed in the gap between the top and bottom portions. Because the heat sink is not disposed on an outer surface, the heat sink can comprise conventional fins, fingers or other shapes for heat dissipation. Also, the top (LED) portion can have a vent hole (fluidically connected to the gap) for convective air flow. Also, the top and bottom portions can be connected in multiple ways (i.e. the bottom portion can have multiple sets of connectors), with each way providing a different type of light output (e.g. color or color temperature). The present LED light bulb provides user-selectable color choices, improved heat dissipation, and interchangeable LED and power electronics.
The bottom portion 22 comprises power supply electronics 36 and a base 38. The power supply electronics can include an AC-DC converter, DC-DC converters, wireless control electronics, or other electronic circuits for controlling or converting electrical power applied to the LEDs 28. The base 38 can be an edison base (as shown) or a bayonet base, for example.
The cover 26 can be liquid-filled, as known in the art, and can be made out of plastic, glass or any other transparent material. The cover 26 can have phosphors for converting light colors, or reflecting elements (not shown) for distributing light, as known in the art.
The gap 24 does not include a solid portion 40 of the heat sink. The gap 24 comprises the space between the top portion 20 and bottom portion 22 that is partially filled with air. The gap can be about 0.030″-1.5″ for example. Typically, the gap will be about ¼″-¾″ wide, but the present invention and appended claims are not so limited.
Preferably, the gap 24 is open to ambient along the entire circumference of the light bulb. Also optionally, and heat sink 32 is contained within the gap 24 and does not extend outside the plane of the gap 24.
The bottom portion 22 has a first connector 41 for engaging with second connectors 42 in the top portion 20. The connectors 4142 provide both electrical connectivity and mechanical attachment between the top portion 20 and bottom portion 22. There must be at least 2 connectors to complete an electrical circuit, of course. For improved mechanical attachment and stability, preferably the connectors are spaced apart as shown, but they can also be next to each other. In the specific embodiment illustrated in
The connectors 4142 can comprise pins, plugs or other connectors in any shape or configuration. For example, the second connectors can comprise round pins or rectangular or square plugs. The connectors 4142 can be covered with a plastic housing, or can comprise bare metal.
A space 45 between the second connectors 42 and the heat sink 32 can be filled with insulating adhesive, resin other material for preventing bending or damage to the connectors 42.
The heat sink 32 has holes 46 to accommodate the second connector 42.
It is noted that the fingers 34 or fins 49 are optional in the invention. The heat sink 32 can comprise a flat, smooth sheet of heat conductive material such as aluminum plate for example.
The vent hole 50 and gap 24 are fluidically connected internally to the light bulb, so that convective air flow is possible through the interior of the light bulb.
In another aspect of the invention, there are multiple ways of connecting the top portion 20 and bottom portion 22. Each way of connecting will provide a different type of light output. Consequently, the user can select a preferred color or light operating mode. For example, one way of connecting the portions 2022 can provide cool white light, another way can provide warm light, another way can provide strobe light, and another way can provide other colors or other lighting modes.
Connector 42-1 and connector 41-1 will be connected, for any of the three orientations.
Also, it is noted that the connectors 41 on the bottom portion can provide different voltage levels, or power functions. For example, the strobe (i.e. pulsing) function can be provided by the power electronics 36 in the bottom portion 22 instead of by the LEDs in the top portion 20.
In the present specification and appended claims, “multiple” means 2 or more (ways of connecting the top portion and bottom portion). For example, there can be 2, 4, 5, 6 or more different ways of attaching the top portion an bottom portion, with each way providing a different type of light output.
In this way, the present LED light bulb can provide a user with a variety of lighting effects that are easily selectable by detaching and reattaching the top portion and bottom portion.
It is noted that the gap 24 does not need to be planar. For example, the gap 24 can alternatively have a conical shape or curved shape.
Since the LED lamps and power electronics are separable in the present invention, a user can easily troubleshoot the lamp to determine if a fault is present in the LED lamps or in the power supply circuit. The power supply circuit, which has a higher failure rate, is easily replaced at lower cost than replacing the entire lamp. Also, a user can purchase various colors of LED lamps without having to purchase an entire lamp. For example, the top portion can be made to provide warm or cool white illumination, and various color temperatures. For parties and special occasions, flashing or colored LED top portions can be used. Since the LED lamps are attached by pins or plugs, they can be easily and quickly changed. And of course changing the type of lamp does not require purchasing an entire new bulb unit-only the LED top portion is required.
The above embodiments may be altered in many ways without departing from the scope of the invention. Accordingly, the scope of the invention should be determined by the following claims and their legal equivalents.
The present application claims the benefit of priority from provisional patent application 61/848,474 filed on Jan. 4, 2013, which is hereby incorporated by reference.
