This patent application claims priority from German Patent Application No. 102016117450.5 filed on Sep. 16, 2016, which is herein incorporated by reference in its entirety.
The present invention relates to a lighting device having an improved connection between light engine and power supply.
In known lighting devices which comprise a light engine, i.e. a device for generating light using light-emitting diodes (LEDs) for example, inside a translucent or transparent bulb, the connection region of the light engine is matched in each case to the associated base which the light engine is initially mounted on by means of individual holding elements before it is fixedly connected to the connection wires of the base, for example by welding.
Based on the known prior art, it is an object of the present invention to provide an improved connection between light engine and power supply. In particular, a certain level of standardization should be possible, that is to say the attachment of different light engines to a standard base.
The object is achieved by a lighting device having the features of the independent claim. Advantageous developments emerge from the dependent claims.
A lighting device according to the invention comprises a translucent (i.e. light-transmissive, in particular transparent) bulb and in addition a light engine arranged in the bulb. A base, i.e. a structure that extends into the interior of the bulb, which is used to hold the light engine, is arranged in the bulb, in particular on its connection side. Such a base usually consists substantially of an elongated element which is provided at one end with a plate-like base. The base comprises two connection wires for connecting the light engine, i.e. both for mechanical mounting and also for electrical connection to the power supply. The light engine itself comprises two connection elements which are electrically and mechanically connected to the connection wires of the base. This connection can be accomplished by welding (e.g. resistance welding, laser welding), soldering, crimping, wrapping, clamping or by other known joining methods.
The connection elements of the light engine each comprise a gripping region and a connecting region. The gripping region is used to hold the light engine on the base during assembly of said light engine (e.g. with a gripper). In the connecting region, the connection between the connection elements of the light engine and the connection wires of the base can then be accomplished as described above. In particular, this connection can only be accomplished point-by-point, i.e. it is not necessary for the connecting region to be connected (e.g. welded) to the connection wires over its entire extent.
The embodiment of the connection elements according to the invention facilitates standardization of the connection between light engine and base or connection wires. It is therefore easily possible to implement a system in which different light engines can be connected to a common design of a base. In particular, this also facilitates site-independent production of the light engines as light engine and base need not be adapted to each other as long as the standardized specifications are complied with. Automation of the production process is also facilitated by the design of the connection elements according to the invention.
In one embodiment, the two connection elements of the light engine are each designed to be planar and are arranged in a common plane. This facilitates, for example, both gripping of the connection elements with a gripper and also positioning the connection elements adjacent to the connection wires of the base in such a manner that the connection referred to above can be made.
In one embodiment of the lighting device, the connecting region of each connection element is angled relative to its gripping region. In particular, the angle between the gripping region and connecting region of a connection element can be between approximately 90° and approximately 135°, e.g. also 100°, 110°, 120° or 130°. In particular, only one of the connection elements can include an angle between the gripping region and connecting region which differs from 180°. In addition, the angle between gripping region and connecting region can differ in size for both connection elements.
An angle between the gripping region and connecting region of a connection element facilitates the alignment of light engine and base, particularly if the connection wires extend from the base in a straight line. Then it is not specifically necessary to hold light engine and base at very precisely determined positions in order to establish a connection between them (e.g. by welding) but rather a certain tolerance range is possible in which both connecting regions and connection wires overlap.
An angle between the gripping region and connecting region of a connection element also allows various light engines, each having different distances between the two connection elements, to be connected to one type of base since the different distance, particularly between the gripping regions of the connection elements, can be bridged by the connecting region extending at an angle to said gripping regions.
The invention also includes the design where the connection wires which extend from the base are angled as described above for the connection elements and the connection elements of the light engine are straight. This “reversal” can also be used in the embodiments illustrated below and is encompassed by the invention.
In one embodiment of the lighting device, the free ends of the connection areas of the two connection elements point away from each other (outwards). As a result, the distance between the gripping regions of the connection elements can be kept small which can be advantageous for the design of the light engine, particularly facilitating compact light engines. Alternatively, the free ends of the connecting regions of the two connection elements can point in the same direction.
In one embodiment of the lighting device, the connecting region of each connection element is U-shaped (this is also understood to mean semicircular). In particular, the closed, round side of the U (or semicircle) can point to the side, i.e. the U can be located on the side opposite the extension of the gripping region, that is to say rotated by 90°. In particular, only one of the connection elements can have a U-shaped connecting region. The connecting region of the other connection element can then be formed, for example, linearly or at an angle to the gripping region (as described above).
In the case of a U-shaped connecting region, advantageously two connection points (crossover points) can be implemented in each case between a connecting region and the associated connection wire as a result of which the light engine can be mounted more sturdily on the connection wires.
Alternatively to a U-shaped connecting region, two connection points can also be implemented with a different configuration of the connection region, for example with a V-shaped connecting region or a different zigzag design.
In one embodiment of the lighting device, the closed, round sides of the U-shaped connecting regions of the two connection elements point away from each other (outwards). As a result, the distance between the gripping regions of the connection elements (as described above in the angled configuration of the connection elements) can be kept small which can be advantageous for the design of the light engine, particularly facilitating compact light engines.
Alternatively, the closed, round sides of the U-shaped connecting regions of the two connection elements can point towards each other (inwards).
In one embodiment of the lighting device, the light engine comprises one or a plurality of LED filaments. An LED filament is understood in this case to be a rod-shaped LED component which normally has a narrow strip of a transparent carrier (e.g. a transparent ceramic, such as sapphire), light-emitting diodes attached thereto in a row and, where appropriate, a fluorescent layer on the light-emitting diodes. Normally one electrical contact is located at each of the two ends of this LED component. Due to the light also radiating through the transparent carrier, such LED filaments allow more even illumination to be achieved without additional optical elements, such as lenses, reflectors or the like. For example, LED filaments marketed under the name Soleriq L 38 by the OSRAM Opto Semiconductors company can be used as LED filaments.
As an alternative or in addition to LED filaments, the light engine can also comprise a planar substrate (preferably transparent, e.g. sapphire) with light-emitting diodes arranged thereon (provided where appropriate with a fluorescent substance to achieve the desired color temperature).
In one embodiment of the lighting device, the light engine comprises a holding structure to which the LED filaments are attached and which is used for supplying power to the LED filaments. Using the holding structure simultaneously for the power supply also avoids additional holders which would lead to undesirable shadow casting.
As the LED filaments are very lightweight (typically a few grams), the holding structure can be very thin and delicate even when using a plurality of LED filaments (e.g. 4, 5, 6, 7, 8) in a light engine, resulting in them casting minimal shadow. For example, the holding structure can consist of wire (e.g. with a diameter of approximately 0.8 mm).
In one embodiment of the lighting device, the holding structure comprises an upper holding element which is electrically connected to a first one of the connection elements. In addition, the holding structure comprises a lower holding element which is electrically connected to a second one of the connection elements. Each LED filament is connected with a first end, which, as described above, can have an electrical contact, to the upper holding element and with a second end, which also, as described above, can have an electrical contact, to the lower holding element. This connection can preferably accomplish both mechanical mounting of the LED filaments on the holding structure and also electrical connection of the two ends of an LED filament to the relevant connection elements via the holding structure.
The two holding elements are thus arranged substantially above or below the LED filaments as a result of which the shadow cast by the holding elements is minimized.
Each of the two holding elements, for example, can be substantially circular or polygonal. Both holding elements can in particular have different shapes. Moreover, both holding elements can be different in size even if they both have substantially the same geometric shape.
Different shapes and/or sizes of the holding elements allow the LED filaments to be positioned such that said LED filaments are not arranged spatially parallel to each other thus minimizing the shadow cast by the LED filaments among each other.
In one embodiment of the lighting device, at least one of the holding elements together with the corresponding connection element and the connection therebetween is formed from a (preferably one-piece) wire. An electrically conductive wire allows the holding structure to be used simultaneously for supplying power to the LED filaments. At the same time, by using a wire for the holding structure, the shadow it casts can be minimized. The wire can consist of metal, preferably steel, and has, for example, a diameter between approximately 0.6 mm and approximately 1 mm, preferably approximately 0.8 mm.
For example, a wire can be shaped such that it starts as an angled or U-shaped connecting region of a connection element and then merges into the gripping region of the connection element. The wire extends further over a connecting region and merges into the upper or lower holding element. In the connecting region, the wire can be straight or it can be angled once or a plurality of times (preferably by approximately 90°). As a holding element, the wire can be bent, for example, in a circle and if necessary can provide a connection substantially in the circular plane to a point inside or outside the circle at which point the wire merges into the connecting region.
In a further embodiment of the lighting device, the light engine further comprises a holder, which connects the two parts of the holding structure, namely the first (partial) structure consisting of the upper holding element, the first of the connection elements and the electrical connection therebetween, and the second (partial) structure consisting of the lower holding element, the second of the connection elements and the electrical connection therebetween in an electrically non-conductive manner such a holder serves to stabilize the holding structure and is then particularly advantageous if the holding structure is thin and delicate in design, if for example both partial structures are each made of a wire.
A holder which connects the two partial structures to each other can be made, for example, of an electrically non-conductive plastic. The holder can preferably be designed in such a way that, after the two partial structures have been produced, it is connected to the two partial structures at locations provided for this purpose. For example, the holder can have a front part and a rear part, each abutting the holding structure from one side, and which are connected to each other, for example, by a snap-in connection. Front part and rear part of the holder are preferably also joined to each other in the non-assembled state by a flexible joining portion which facilitates mounting of the holder on the holding structure.
In one embodiment of the lighting device, the LED filaments are electrically connected in parallel. This enables special designs for the construction of an electronic driver for controlling the LED filaments.
In a further embodiment of the lighting device, the bulb is designed to be gas-tight and is filled with a gas for heat dissipation of the heat generated by the light engine, in particular with a gas that has high thermal conductivity. The gas preferably contains helium and/or hydrogen. The gas can also be a gas mixture of various gases. Such a gas for heat dissipation allows the LED lighting strip to be operated inside a closed bulb without additional heat sinks.
In one embodiment of the lighting device, the bulb and the base are made of glass. The base can then be fused with the bulb. At the same time, the connection wires can be fused into the base. As a result, it is possible in particular to bring about gas-tightness of the bulb. The connection wires protrude out of the base both inside the bulb and also outside the bulb. Inside the bulb, the connection wires are used for mechanical mounting of the light engine and for its power supply, as described above. Outside the bulb, the connection wires can be used with an electronic driver for controlling the light engine and in particular the LED filaments.
In one embodiment, the lighting device further has a socket. The lighting device can be fastened with this socket in a light fitting matching said socket.
The lighting device preferably also comprises a driver for controlling the light engine. The driver can be arranged inside the socket and can be electrically connected to the connection wires guided out of the bulb.
The bulb can be mechanically connected to the socket by a cement or an adhesive. This enables the bulb and socket to be connected without additional components. The bulb can preferably be designed such that its end directed towards the socket can be inserted into a portion of said socket. This provides a sufficiently large adhesive surface for connecting the bulb and socket.
Preferred further embodiments of the invention will be explained in greater detail using the following description of the figures. In this case the drawings show:
Preferred embodiments will be described below based on the figures. In this case, identical, similar or equivalent elements are provided with the same reference numbers in the different figures and repeated description of these elements is partly omitted to avoid redundancies.
A light engine 5 which is arranged inside the bulb 1 comprises two connection elements 6 which are mechanically and electrically conductively connected to the connection wires 4 in a connecting region, preferably they are welded at the crossover points of connection wires 4 and connection elements 6. The light engine 5 will be described in greater detail below with reference to
The light engine 5 according to
Even if the following figures each show one of the aforementioned two light engines, the other light engine or even a light engine not described in greater detail herein can always be used.
It can also be seen from
The illustration in
The U-shaped configuration of the connecting portion 10 results in two crossover points 11 existing between each connecting portion 10 and the associated connection wire 4, at which points the connection elements 6 are mechanically and electrically conductively connected to the connection wires 4 by a welded joint. This leads in particular to a more sturdy mechanical connection of the light engine 5 to the base 3.
Both partial structures 14, 15 are each bent in one piece from a steel wire 0.8 mm thick.
The wire then runs straight down up to an S-shaped bend 19 (approximately 90° twice in opposing directions). After the S-shaped bend 19, the wire extends further downwards and merges into the gripping portion 9 of the connection element 6. After a further bend by approximately 45°, the wire ends as connecting portion 10 of the connection element 6.
The two circular portions 17, 20 of the partial structures 14, 15 have different diameters such that the LED filaments 12 are not parallel to each other when they are attached with their ends 13 to the circular portions 17, 20. This can be seen in
The holder 16, which connects the two partial structures 14, 15 to each other in an electrically non-conductive manner, is shown open in
The bulb 1 is inserted with its lower end into the socket 2 and is fixed in this overlap area 30 by means of a cement or an adhesive.
It can be seen from
The illustration in
In the embodiment according to
In the embodiment according to
In the embodiment according to
In the embodiment according to
Although the invention has been illustrated and described in greater detail using the embodiments shown, the invention is not limited thereto and a person skilled in the art may derive other variations therefrom without departing from the scope of protection of the invention.
Generally, “one” may be understood to mean a single figure or a plurality, particularly in the sense of “at least one” or “one or more”, etc., as long as this is not explicitly excluded, e.g. by the expression “exactly one”.
A specified figure may also include exactly the number and also a customary tolerance range, as long as this is not explicitly excluded.
Where applicable, all the individual features illustrated in the embodiments can be combined and/or replaced with each other without departing from the scope of the invention.
Number | Date | Country | Kind |
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102016117450.5 | Sep 2016 | DE | national |
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202014004861 | Aug 2014 | DE |
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Number | Date | Country | |
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20180080611 A1 | Mar 2018 | US |