DE29817609U1 - Illuminant - Google Patents

Description

Gesthuysen & von Rohr

98.645.4.CO Essen, 30 September 1998

Utility model application

Gabriele Derksen Sauerlandstrasse 5

45889 Gelsenkirchen

with the label

Lamps

Gesthuysen & von Rohr - 1 -

The present invention relates to a lighting device with a plurality of light-emitting diodes arranged distributed over a surface.

Light-emitting diodes, also known as LEDs for short, are semiconductor components that emit light in a relatively concentrated or directed manner. Light-emitting diodes have the advantage that a high light output can be achieved with relatively little heat development.

It is already known to arrange a large number of light-emitting diodes in a plane next to one another and with essentially parallel or convergent main emission directions. In this way, the directional characteristics already present in a light-emitting diode are exploited to provide lighting devices with a relatively strong concentration of the emitted light.

The present invention is based on the object of providing a lighting device which can be used as universally as possible, which has a long service life with good light output and a relatively high luminous flux and which can be produced relatively inexpensively.

The aforementioned object is achieved by a lighting means according to claim 1 or 3. Advantageous further developments are the subject of the subclaims.

A basic idea of the present invention is to arrange the light-emitting diodes in a distributed manner over the surface in such a way that their main emission directions diverge. This counteracts the directional effect inherent in the light-emitting diodes, so that better illumination is achieved with the proposed light source and thus a more universal usability of the light source for lighting purposes. In this respect, the present invention also takes a different approach than the prior art.

Ideally, most, preferably all, LEDs have their main emission directions pointing in different directions, diverging from each other. This enables light to be emitted from all directions.

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Gesthuysen & von Rohr - 2 -

In order to enable a high luminous flux overall, it is intended that a large number of LEDs are used distributed over a large area. A large number is understood here to mean more than 10, preferably more than 50 or 100 LEDs.

An aesthetically pleasing overall impression is achieved by arranging the LEDs distributed over a surface. The position of the individual diode housings that define the surface in which the LEDs are located is important here. However, it is not important and is fundamentally irrelevant from an aesthetic point of view, particularly when the LEDs are very densely packed, what is located on the side of the surface opposite the main emission direction of the LEDs, for example whether a circuit board is assigned to the LEDs and, if so, at what distance and in what shape. However, a particularly simple production can be achieved by having a circuit board, in particular a flexible one, that carries the LEDs, running essentially parallel to the surface defined by the LEDs, i.e. with an essentially similar surface shape.

In a particularly preferred embodiment, the lighting means is provided with an at least partially translucent housing, which preferably has at least substantially the shape of a conventional lighting means, such as a fluorescent tube or an incandescent lamp. The housing, which is made in particular of glass, can be optionally frosted or clear.

The proposed light source is preferably provided with one or more conventional sockets and can then easily replace standard light sources such as conventional light bulbs or energy-saving lamps, whereby the proposed light source has further advantages and accordingly opens up further areas of application. This is further supported by the fact that light-emitting diodes that emit white light are now also available, so that a light corresponding to conventional light bulbs or fluorescent tubes, for example, can be generated by the proposed light source depending on requirements and the choice of material.

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Gesthuysen & von Rohr - 3 -

In particular, the proposed lighting device has a comparatively low power consumption and generates only a small amount of heat, so that the proposed lighting device can be used in cold stores, cold stores, etc. This is further supported by the fact that the light emission of the LEDs increases with decreasing temperature.

The resistance to low temperatures also makes the proposed lamp particularly suitable for outdoor lighting systems.

The long service life of the proposed lamp reduces the frequency of replacement, so that the proposed lamp is particularly suitable for use in hard-to-reach places and/or in applications with long switch-on times.

Due to its reliability, the proposed lamp is also particularly suitable for emergency lighting systems.

In a particularly preferred embodiment, the LEDs are distributed in a spherical surface with the main emission direction pointing at least substantially radially outwards. This results in particularly uniform illumination in all directions and a particularly aesthetic overall impression. However, the LEDs can also be arranged in a different, possibly irregularly curved surface, for example a parabolic surface, the surface of an ellipsoid, a drop-shaped or pear-shaped surface or another surface of second or higher order or a part or section thereof.

The proposed light source also has the advantage that the light source can be adapted very easily to a wide variety of applications and desired lighting properties by selecting the number of light-emitting diodes used, the colors of the light-emitting diodes and the type and strength of the light-emitting diodes.

The present invention is explained in more detail below with reference to the accompanying drawings of some embodiments. In the drawing:

Gesthuysen & von Rohr -A-

Fig. 1 is a schematic sectional view of a light-emitting diode;

Fig. 2 is a schematic sectional view of a proposed illuminant

according to a first embodiment;

Fig. 3 is a side view, partially in section, of a proposed

Lighting means according to a second embodiment;

Fig. 4 is a section along line IV-IV of Fig. 3;

Fig. 5 is a side view of a proposed illuminant according to a

third embodiment;

Fig. 6 is a longitudinal section of the illuminant according to Fig. 5; and

Fig. 7 is a side view of a proposed lighting means according to a fourth embodiment.

The present invention is explained in more detail below with reference to the drawing. In the figures, the same reference numerals are used for identical or similar parts, whereby identical or comparable technical effects and advantages are achieved in each case, even if a repeated description is omitted.

Fig. 1 shows a schematic of the basic structure of a light-emitting diode (LED) 2. The light-emitting diode 2 has a semiconductor element 4 arranged in a diode housing 3, which can be electrically connected and operated via connecting wires 5 emerging from the diode housing 3. During operation, the semiconductor element 4 emits light which, as indicated by arrows 6, emerges from the at least partially transparent diode housing 3 in a relatively strongly bundled or directed manner, so that a main emission direction 7 results.

Fig. 2 shows a first embodiment of a proposed luminous means 1 with a plurality of light-emitting diodes 2, which are distributed in a flat surface 8 and arranged such that their main emission directions 7, at least that of the largest

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Gesthuysen & von Rohr - 5 -

Part of the light-emitting diodes 2 diverge. Here, the divergence of the main emission directions 7 is achieved by a corresponding tilting of the respective diode housings 3 relative to one another, wherein the diode housings 3 are arranged at least substantially in the flat surface 8 and thereby define it.

In the example shown in Fig. 2, a circuit board 9, to which the light-emitting diodes 2 are electrically connected, carries the light-emitting diodes 2. The circuit board 9 here runs at least substantially parallel to the surface 8; however, this is not absolutely necessary.

Fig. 3 shows a second embodiment of the proposed lighting device 1. Here, the lighting device 1 essentially has the shape of a conventional fluorescent tube, but instead of a gas discharge, a large number of light-emitting diodes 2 are arranged inside the lighting device 1 in a distributed manner in a surface 8, the surface 8 being curved at least in one direction of extension and here at least essentially in the shape of a circular cylinder. The light-emitting diodes 2 are arranged in such a way that their main emission directions 7 are directed at least essentially radially outwards, as can be seen from the cross section according to Fig. 4.

The lighting device 1 according to the second embodiment has, as shown in Fig. 3, two sockets 10 with electrical contact elements 11. The two sockets 10 are arranged at the two ends of a housing 12 which is here essentially hollow-cylindrical in shape and which is translucent, in particular made of glass, and as a casing additionally protects the light-emitting diodes 2 and, due to its smooth surface, makes cleaning the lighting device 1 much easier.

The sockets 10 close the housing 12 at the end, wherein the contact elements 11 serve on the one hand for an electrical connection of the light-emitting diodes 2 or an electrical circuit 13 preferably arranged in the lighting means 1 for supplying power to the light-emitting diodes 2 and on the other hand, together with the sockets 10, for a mechanical holder of the lighting means 1 in the installed state.

Gesthuysen & von Rohr - 6 -

The electrical circuit 13 is preferably arranged at least partially or completely within the sockets 10 and/or within a space section 14 delimited by the LEDs 2 or the circuit board 9, which enables a compact construction of the lighting device 1. The sectional view according to Fig. shows that the electrical circuit 13 arranged in the space section 14 can, depending on its own stability, support the circuit board 9 via support elements 15 or form a composite structure of sufficient stability with the circuit board 9 or other parts supporting the LEDs 2. Electrical connecting wires 16 indicate the power supply of the LEDs 2 by the electrical circuit 13.

In the case of the light source 1 according to the second embodiment, the surface 8 is continuously curved at least in one cutting plane, namely the plane running radially on the longitudinal axis, so that when the diode housing 3 is aligned at least substantially non-tilted relative to the surface 8, diverging main emission directions 7 result at least for a large proportion of the light-emitting diodes 2 or at least for all the light-emitting diodes 2 lying in the cutting plane.

Fig. 5 shows a third embodiment of the proposed lighting means 1. Here again, a plurality of light-emitting diodes 2 are arranged in a curved surface 8 - as can be seen from the sectional view according to Fig. 6 -, the surface 8 here being essentially spherical, so that all or at least almost all light-emitting diodes 2 have main emission directions 7 pointing radially outwards in different directions.

The lighting device 1 according to the third embodiment essentially has the shape of a conventional light bulb. Accordingly, the housing 12 is designed, for example, as a spherical piston, a cylindrical piston or a pear-shaped, and the socket 10 closing the housing 12 is designed, for example, as a standard socket, such as E27, so that the proposed lighting device 1 can be used directly instead of conventional light bulbs or energy-saving lamps with the same socket.

The spherical or possibly other shaped light-emitting diode arrangement is preferably at least substantially in the middle of a protective casing

Gesthuysen & von Rohr - 7 -

representing housing 12 and is held, for example, by a holding element 17 attached to the socket 10. The holding element 17 is, for example, cast with an insulating material at one end into the socket 10 and is preferably hollow so that connecting wires 16 serving to supply power to the light-emitting diodes 2 or the electrical circuit 13 connected upstream of the light-emitting diodes 2 can be led from electrical contact elements 11 of the socket 10 through the holding element 17 to the light-emitting diode arrangement or to the optionally provided electrical circuit 13.

In the example shown, as can be seen from Fig. 6, the electrical circuit 13 is arranged within the space section 14 delimited by the LEDs 2 or the circuit board 9 carrying the LEDs 2. However, the electrical circuit 13 can alternatively or additionally be partially integrated into the socket 10.

In addition, a reflector 18, as indicated in Fig. 6, can be arranged inside the lamp 1. The reflector 18 is formed, for example, by a dome-shaped, reflective element, in particular made of metal or coated with it, or depending on the application, spatially curved in another way, a reflective inner coating or a reflective inner coating of the housing 12 or other inner surfaces of the lamp 1. The reflector 18 serves to redirect light emitted by the light-emitting diodes 2 onto the reflector 18 in a desired direction.

The shape of the surface 8 is not limited to the spherical shape, particularly in the illustrated third embodiment of the proposed lighting means 1, but the surface 8 can also be curved in another way, for example irregularly and take on the shape of an ellipsoid, an egg shape, a pear shape or the like, wherein the light-emitting diodes 2 can also be arranged in only one section or several sections of the surface 8 and/or with different surface densities, depending on the application.

The proposed lighting device 1 has the advantage, with appropriate design of the electrical circuit 13, that it can be connected, for example, to a conventional power supply.

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Gesthuysen & von Rohr - 8 -

can be directly connected to a 220 V AC or 110 V AC supply and can therefore directly replace conventional lamps.

The light-emitting diodes 2 are preferably designed to emit white light. However, depending on requirements, light-emitting diodes 2 that emit colored light can also be used, possibly mixed. For example, red, green and blue light-emitting diodes 2 can be distributed in a distributed manner, which when switched on simultaneously produce at least essentially white light by superimposing them, or when switched on or controlled accordingly can produce different colored effects and, ideally, the complete color spectrum. Very impressive lighting effects can be achieved, particularly in combination with a frosted glass ball, hood or the like that envelops the light-emitting diodes 2.

The light emitted by the illuminant 1 can alternatively or additionally be modified by the housing 12 having coatings that modify the emerging light and/or by being made of colored glass. In addition, all other measures for modifying the emerging light, as are known from previous illuminants, can also be used.

It is also possible to evacuate the housing interior or fill it with a specific gas depending on requirements and, for example, the desired heat transfer properties.

In order to realize a "dimnV" effect or to be able to easily adjust the brightness of the light source 1 as required, according to one embodiment variant, individual groups of light-emitting diodes 2 can be switched on and off or connected separately, whereby this can be realized by the electrical circuit 13 integrated in the light source 1 or, if the internal electrical circuit 13 is omitted, by corresponding external control of the light source 1 if corresponding connection options are provided.

The aforementioned discrete or selective switching on or control of individual and/or groups of light-emitting diodes 2 can be carried out alternatively or in addition to the above-mentioned

•t· ··

Gesthuysen & von Rohr - So-called 'DimnV' effect can be used to realize so-called running light effects or blinking effects.

Fig. 7 shows a fourth embodiment of the proposed lighting device 1, which can preferably be used as a type of flashing light. The lighting device 1 has a large number of light-emitting diodes 2, which are arranged essentially distributed in or over a circular cylindrical surface in such a way that several light-emitting diodes 2 are arranged in rows running at least essentially parallel to the cylinder axis. The light-emitting diode arrangement is preferably held by a holding element 17, preferably at least essentially in the middle of the transparent housing 12, which forms a protective casing and which is here in the shape of a cylinder hood or essentially in the shape of a test tube and preferably made of glass or a transparent plastic. On the side opposite the holder 17, the light-emitting diode arrangement has an essentially dome-shaped or cap-shaped arrangement of the light-emitting diodes 2, but this is optional.

The housing 12 is closed by a socket 10 or the like having an integrated reflector 18.

The lighting device 1 according to the fourth embodiment is provided in the example shown with a supply line 19 for selectively controlling in particular individual rows of light-emitting diodes 2. Alternatively, however, an electrical circuit 13, as in the previous embodiments, can also be integrated into the lighting device 1 in order to enable in particular this selective controlling or switching on of individual groups or rows of light-emitting diodes 2.

The proposed design of the lighting means 1 according to the fourth embodiment enables individual or multiple rows of light-emitting diodes 2 arranged in succession in the circumferential or curvature direction to be switched on and off one after the other, so that if, for example, two rows of light-emitting diodes 2 arranged vertically in the illustration according to Fig. 7 are switched on one after the other all around, a flashing or warning light can be imitated without

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Gesthuysen & von Rohr - 10 -

it requires a moving element, as is usual with warning lights on police or fire service vehicles.

Of course, the linear or row-shaped arrangement of at least some of the LEDs 2 can also be provided in the lighting means 1 according to the second and third embodiments or in other LED arrangements. Thus, instead of the essentially cylindrical jacket-shaped arrangement of the LEDs 2 according to Fig. 7, another, preferably essentially rotationally symmetrical LED arrangement can also be provided, with some LEDs 2 in particular being arranged along circumferential lines running along the outer contour and/or along outer contour lines, which represent intersection lines of planes running through the axis of rotation with the outer contour of the LED arrangement or the surface 8, and can be selectively controlled or switched off accordingly.

The light source 1 with the warning light function or the surrounding rows or lines of switched-on light-emitting diodes 2 can be used, for example, in police cars, security vans, ambulances, seawater buoys, radio towers, position lights on buildings or the like.

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Claims (17)

1. Illuminant ( 1 ) with a plurality of light-emitting diodes ( 2 ) arranged distributed over a surface, characterized in that at least some of the light-emitting diodes ( 2 ) are arranged such that their main emission directions ( 7 ) diverge. 2. Lighting means according to claim 1, characterized in that the light-emitting diodes ( 2 ) are arranged at least substantially in a flat surface ( 8 ) and at least partially tilted relative to one another. 3. Illuminant ( 1 ) with a plurality of light-emitting diodes ( 2 ) distributed over a surface, in particular according to claim 1, characterized in that
that the light-emitting diodes ( 2 ) are distributed in a surface ( 8 ) which is curved in at least one direction of extension, and
that the light-emitting diodes ( 2 ) are arranged with the main emission directions ( 7 ) pointing away from the centre of the curvature. 4. Illuminant according to claim 1 or 3, characterized in that the light-emitting diodes ( 2 ) are arranged distributed in a cylinder-shell-shaped, in particular circular cylinder-shell-shaped surface ( 8 ). 5. Lighting means according to claim 1 or 3, characterized in that the light-emitting diodes ( 2 ) are arranged distributed at least in a section of a parabolic, ellipsoidal, pear-shaped, spherical or other spherical surface ( 8 ) or a surface ( 8 ) of second or higher order. 6. Lighting means according to one of the preceding claims, characterized in that the lighting means ( 1 ) has a printed circuit board (9) which runs at least substantially parallel to the surface ( 8 ) defined by the light-emitting diodes ( 2 ), in particular a flexible printed circuit board ( 9 ) which carries the light-emitting diodes ( 2 ). 7. Lighting means according to one of the preceding claims, characterized in that the lighting means ( 1 ) has at least one socket ( 10 ) for the electrical connection of the light-emitting diodes ( 2 ) and for holding the lighting means ( 1 ). 8. Illuminant according to one of the preceding claims, characterized in that the illuminant ( 1 ) has a housing ( 12 ) which is at least partially translucent, in particular made of glass, and which at least partially surrounds the light-emitting diodes ( 2 ). 9. Lighting means according to claims 7 and 8, characterized in that the lighting means ( 1 ) has an electrical circuit ( 13 ) connected to the socket ( 10 ) for supplying power to and/or controlling the light-emitting diodes ( 2 ), which is arranged in the housing ( 12 ), in particular at least partially within a spatial section ( 14 ) delimited by the light-emitting diodes ( 2 ). 10. Illuminant according to claims 4 and 9, characterized in that the housing ( 12 ) is at least substantially tubular and is closed at each end by a socket ( 10 ). 11. Illuminant according to claims 5 and 9, characterized in that the housing ( 12 ) is at least substantially pear-shaped or cylindrical, the housing ( 12 ) being closed off by the socket ( 10 ). 12. Lighting means according to one of the preceding claims, characterized in that the lighting means ( 1 ) has a reflector ( 18 ) associated with the light-emitting diodes ( 2 ). 13. Illuminant according to claim 12, characterized in that the reflector ( 18 ) is arranged together with the light-emitting diodes ( 2 ) in a common housing ( 12 ) which is at least partially translucent. 14. Lighting means according to one of the preceding claims, characterized in that the light-emitting diodes ( 2 ) are designed such that they emit substantially white light. 15. Lighting means according to one of the preceding claims, characterized in that the lighting means ( 1 ) is designed such that individual groups of light-emitting diodes ( 2 ) can be selectively switched on or off. 16. Lighting means according to one of the preceding claims, characterized in that the light-emitting diodes ( 2 ) are at least partially arranged in lines or rows, wherein the main emission directions ( 7 ) of the light-emitting diodes ( 2 ) of a line or row in particular run at least substantially in a common plane. 17. Lighting means according to claims 15 and 16, characterized in that the light-emitting diodes ( 2 ) of a line or row can be selectively switched on or off partially and/or as a group as a whole.