Patent ID: 12241597

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplifying embodiments of the present invention are shown. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments of the present invention set forth herein; rather, these embodiments of the present invention are provided by way of example so that this disclosure will convey the scope of the invention to those skilled in the art. In the drawings, identical reference numerals denote the same or similar components having a same or similar function, unless specifically stated otherwise.

As partly mentioned before, LED filament lamps increasingly replace conventional light bulbs. The manufacturing of LED filament lamps may therefore utilize the existing infrastructure for conventional light bulbs. Therefore, LED filament lamps often comprise an envelope sealed with a stem, but wherein the stem has only two (conventional) electrical connections to the chamber enclosed by the envelope. However, LED filament lamps may comprise a LED filament structure with multiple individually controllable segments, such as e.g. LED filaments with different respective color temperatures or a single LED filament with different color strings. This means that for N individually controllable segment, the LED filament lamp requires N+1 wires through the stem for enabling individual control of said segments. This is a clear disadvantage, because an increased number of electrical connections through the glass stem adds costs to manufacturing, adds complexity to the stem design, and a clear burden to the established manufacturing procedures used, and even further reduces the reliability of the stem of the bulb (i.e. e.g. a metal-glass bonding of the stem).

As mentioned, the present invention advantageously provides a multi-channel (or multi-segment) LED filament lamp, wherein the complexity and/or costs of manufacturing said multi-channel LED filament lamp is reduced, but also the reliability of the seal of the stem is improved (as less electrical connections are required through the stem for enabling the multi-channel control of the LED filament lamp).

FIGS.1A &1Bdepict schematically an embodiment of a LED filament lamp10according to the invention.FIG.1Bdepicts a scheme of the LED filament lamp10components. The LED filament lamp10comprises an envelope11, a stem12, a LED filament structure14, a controller15, a sensor17and a driver circuit16. The LED filament lamp10also has a base comprising a screw, so as to screw said LED filament lamp in a socket. The driver circuit16is thereby arranged within the base.

The envelope11is a glass bulb. The stem12is a glass stem. The envelope11seals a chamber13together with the stem12. The stem12extends into said chamber13. Said chamber may e.g. be filled with gasses commonly known for filling light bulbs, such as e.g. nitrogen, argon or helium. Such gasses may also improve the thermal properties of the LED filament lamp and improve heat transfer. The envelope and/or stem may alternatively be made of any other material, such as a polymer or a ceramic.

The LED filament structure14, the sensor17and the controller15are mounted on the stem12and are thereby arranged within the chamber13. The LED filament structure14comprise five individually controllable LED filaments141,142,143,144,145; each of said five LED filaments comprising a respective individually controllable segment. Said segments may also be phrased as channels or strings. Each segment of said individually controllable segments (thus each LED filament) outputs a different lighting characteristic. Here, the lighting characteristic is color temperature. Hence, the first LED filament141has a first color temperature, the second LED filament142has a second color temperature, the third LED filament143has a third color temperature, the fourth LED filament144has a fourth color temperature, and the fifth LED filament145has a fifth color temperature. The color temperatures may differ due to the LED filaments having a different phosphor layer (coating) and/or LED light sources. The color temperatures may range in tones between e.g. warm-white and cold-white. Alternatively, in some examples, at least two segments of the individually controllable segments may output a different lighting characteristic.

The driver circuit16comprises two powerlines161,162extending through the stem12that power the LED filament structure14and the controller15. The driver circuit comprises a main control circuit (not explicitly referenced to). The main control circuit receives power and is operationally arranged to control the LED filament structure by means of conveying control signals. The driver circuit16also comprises a separate control line163extending through the stem12and connecting to the controller15. The driver circuit16is arranged outside the chamber14. The driver circuit16conveys a control signal to the controller15via said control line163. The controller15is arranged to receive said control signal and, based on said control signal, control each of the five individually controllable LED filaments141,142,143,144,145and their respective individually controllable segment.

Moreover, in aspects, the main control circuit comprised by the driver circuit16may convey a coded signal to the controller15. The controller15may be configured to decode the received control signal into a decoded control signal, and thereafter control each of the five individually controllable LED filaments141,142,143,144,145and their respective individually controllable segment based on said decoded control signal. The driver circuit may thereby utilize known techniques, such as Amplitude Modulation, Pulse-Width-Modulation, or Time-Division Multiplexing.

All in all, because the invention provides the controller15within the chamber13, and because the driver circuit16conveys said control signal to the controller15via the separate control line163extending through the stem12, the LED filament lamp10enables multi-segment control of the LED filament structure14with the five individually controllable LED filaments141,142,143,144,145and their respective individually controllable segment, without having to need more than three electrical connections through the stem12.

FIGS.2A &2Bdepict schematically an embodiment of a LED filament lamp20according to the invention.FIG.2Bdepicts a scheme of the LED filament lamp20components. The LED filament lamp20comprises an envelope21, a stem22, a LED filament structure24, a controller25, and a driver circuit26.

The envelope22is a glass bulb. The stem22is a glass stem. The envelope21seals a chamber23together with the stem22. The stem22extends into said chamber23. The envelope and/or stem may alternatively be made of any other material, such as a polymer or a ceramic.

The LED filament structure24is mounted on the stem22. The LED filament structure24is a single LED filament comprising four individually controllable channels241,242,243,244. Said segments may also be phrased as channels or strings. Each segment of said individually controllable segments241,242,243,244outputs a different lighting characteristic. Here, the lighting characteristic is color. Hence, the first segment241may comprise a red LED light source, the second segment242may comprise a blue LED light source, the third segment243may comprise a green LED light source, and the fourth segment244may comprise warm-white LED light source (e.g. with a phosphor layer).

Here, the LED filament structure24comprises the controller25. Alternatively, the controller may be arranged on the stem. The LED filament structure24and the stem22are thus arranged within the chamber23.

The driver circuit26comprises two powerlines261,262extending through the stem22that power the LED filament structure24and the controller25. The driver circuit26is arranged outside the chamber24. The driver circuit26transmits a control signal to the controller25via at least one of said powerlines261,262by means of Power Line Communication (PLC). The driver circuit may thereby utilize known techniques, such as Amplitude Modulation, Pulse-Width-Modulation, or Time-Division Multiplexing. The controller25is arranged to receive said control signal and, based on said control signal, control each of the four individually controllable segments241,242,243,244.

All in all, because the invention provides the controller25within the chamber23, and because the driver circuit26conveys said control signal to the controller25via the two powerlines162,161extending through the stem22, the LED filament lamp20enables multi-segment control of the LED filament structure24with the four individually controllable LED segments241,242,243,244, without having to need more than two electrical connections through the stem22.

In an embodiment, not depicted, the LED filament lamp according to the invention is partly similar to the embodiments depicted inFIGS.1A-Band2A-B, but wherein the LED filament lamp comprises wireless connectivity. More specifically, the driver circuit comprises a main controller circuit in communication with a wireless receiver or transceiver. The wireless receiver is configured to receive wireless control messages by means of a wireless modality. The wireless modality may be Bluetooth, Wi-Fi, ZigBee, VLC, IR, RF, Lo-Ra, NFC, RFID, etc. The control messages may subsequently be converted, by the main controller circuit comprised by the driver circuit, to the control signal according to the invention. The driver circuit is thereby conveying a control signal to the controller arranged within the chamber.

FIG.3depicts schematically an embodiment of a method30according to the invention. The method30may be performed by the LED filament lamp depicted inFIG.1and/orFIG.2. The method30comprises a step31of powering, by the driver circuit arranged outside the chamber, the controller via two powerlines extending through the stem. The method30further comprises a step32of conveying, by the driver circuit, a control signal to the controller via a control line extending through the stem. The method30further comprises a step33of receiving, by the controller, said control signal and controlling each of the (respective) plurality of controllable channels based on said control signal. Said control line may in some examples be at least one of the powerlines.

In some examples, the method may comprise a step of decoding the received control signal into a decoded control signal, and controlling each of the (respective) plurality of individually controllable segments based on said decoded control signal. In some examples, the method may comprise a step of transmitting, by the driver circuit, said control signal to the controller by means of Power Line Communications (PLC).