EP3090200A1

EP3090200A1 - Light tube

Info

Publication number: EP3090200A1
Application number: EP14736714.8A
Authority: EP
Inventors: Hans-Jürgen LAMMERT; Nils Oliver LAMMERT
Original assignee: Clevalux GmbH and Co KG
Current assignee: Clevalux GmbH and Co KG
Priority date: 2013-12-02
Filing date: 2014-07-01
Publication date: 2016-11-09
Also published as: WO2015082087A1; DE202013105473U1

Abstract

The invention relates to a light tube that is equipped with an at least partially transparent housing (1, 2) and at least one lamp (7) that is arranged in the housing (1, 2). According to the invention, the LED lamp (7) is designed as at least one continuous single-piece LED luminous strip (7) that is adjusted to the length (L) of the housing.

Description

fluorescent tube

Description:

The invention relates to a luminous tube, with an at least partially transparent housing, and with at least one arranged in the housing LED bulbs. LEDs (Light Emitting Diodes) are increasingly used in all fields, where it comes to provide a long-lasting lighting with high light output. For example, WO 2010/063492 A2 is known for such a luminous tube, which is equipped in the interior with a plurality of point light sources arranged in the direction of the longitudinal axis of the tube in the form of LEDs. As a result, a conventional gas discharge path can in principle be replaced.

In order to make the light emitted selectively from the individual LEDs, which are provided in a plurality of LEDs, appear diffuse in the generic type fluorescent tube. This can be realized by irradiating the transparent housing in this area with sand or other suitable particles.

However, the disadvantage of such a scattering layer is that it largely destroys the high luminous efficacy of LEDs in favor of diffuse radiation. For such scattering layers typically have an absorption of more than 10% of the emitted luminous intensity, that is, the light emitted by the LEDs is at least attenuated by this amount. In addition, in practice, a consistently diffuse light impression can not or hardly be achieved even with such a scattering layer. This is where the invention starts.

The invention is based on the technical problem of further developing such a luminous tube in such a way that an optically homogeneous luminous impression is achieved, taking into account a structurally simple structure and with the lowest possible energy costs.

To solve this technical problem, a generic arc tube in the invention is characterized in that the LED light source is designed as at least one matched to the housing length integral and continuous LED light strip.

In the context of the invention, the housing is at least partially transparent. Here it has proven useful to work with at least one transparent strip in the housing, which typically extends over the entire housing length. As a consequence thereof, the at least one LED light strip realized according to the invention also has a corresponding length. Because this is generally adapted to the length of the transparent strip and consequently the housing length. In addition, the LED light strip is integrally formed, so is not composed of point light sources as the prior art. Rather, the entire LED light strip acts as a surface radiator. The LED light strip is additionally designed for this purpose - that is, without interruption.

In order to achieve the widest possible light emission with a corresponding radiation angle, the transparent strip or LED light strip in the housing normally radiates at an angle of at least 100 ° to mostly 180 °, assuming a circular or nearly circular housing in cross-section. This solution can for example be realized so that the housing is formed in two parts with a metallic lower part and a transparent upper part. In the transparent top

it can be a transparent tube, which accommodates the metallic lower part for holding the LED light source in its interior.

As a rule, however, two housing parts are realized, which are releasably coupled together. At this point can be worked with a thrust connection, a snap-in connection, a clamping connection, etc. Combinations are also conceivable. The described connection is provided in each case on longitudinal wheels of the two housing parts. In most cases, the design is such that the housing is composed of the predominantly semicircular metallic lower part and the likewise predominantly semicircular transparent upper part, which adjoin each other at their longitudinal edges and are coupled together via the detachable connection already mentioned.

The lower part can be made of aluminum and / or plastic. For the upper part, the invention recommends the use of a transparent plastic. In principle, you can also work with glass. However, one will then typically resort to a glass tube or a transparent plastic tube, which receives the metallic lower part in its interior. If a transparent plastic for the realization of the upper part or of the entire cylindrical tube is used, a food-compatible plastic has proven particularly useful at this point. In fact, PMMA (polyoxymethacrylate) is usually used here, although of course the use of transparent polyethylene (PE) is also possible and is encompassed by the invention.

The use of a food-compatible plastic for the realization of the transparent upper part or the entire cylindrical tube

allows a universal use of the arc tube according to the invention. This can not only be used as a replacement for conventional fluorescent tubes, but can also be used, in particular, for illuminating foods in, for example, refrigerated counters. It goes without saying that the transparent plastic is optionally colored in order to change the color of the light emitted by the LED illuminant. In principle, this can also be done by a corresponding design of the LED light source, which is usually a white light LED illuminant or a corresponding white light LED light strip. In fact, the white light is generated by a color mixture of red, green and blue LEDs. Depending on their composition and light intensity, it is conceivable to change the emitted white light spectrum as desired, without having to work with a colored transparent top.

As a result, the invention can generally rely on a transparent and in particular glass-clear upper part and is unnecessary because of the flat and continuous character of the inventively used and adapted to the housing length LED strip of additional use of a litter layer or other scattering measures. As a result, the entire luminosity of the LED illuminant used without attenuation is available on the output side of the arc tube according to the invention.

In addition, the continuous planar character of the LED strip produced according to the invention produces a homogeneous light field and, in particular, the punctual luminous character observed with conventional LED-based tube lights is avoided. All of this is possible without the need for additional diffuse scattering agents and consequently a weakening of the emitted light intensity.

According to another embodiment of the invention with particular importance, two housing parts are also realized, which are releasably coupled together. In this case, the housing parts are not designed as upper part and lower part. Rather, it is particularly advantageous to a housing shell on the one hand and a housing insert on the other. The housing shell is formed as a rule cylindrical and transparent. In fact, the previously mentioned transparent plastic is again used, as has been described with reference to the other embodiment for the realization of the local upper part. That is, the case may be made of transparent PMMA, although of course, transparent polyethylene can be used.

In addition, the housing shell may be at least partially opaque formed as an alternative. That is, the light emitted from the LED bulb is scattered white, the so-called wavelength independent modulation control takes place. The inserted into the cylindrical housing and held therein housing insert in turn carries the LED light strip. The housing insert may be made of suitable materials such as plastic, metal and combinations. Moreover, it has proven useful if the LED light strip is received in an elongated groove in the housing insert. Both sides of the groove, the housing insert may be equipped with painted side bars. The elongated groove for receiving the LED strip is arranged centrally compared to the housing. The two laterally extending side webs in this context include an opening angle of about 140 °, so that the LED light strip is not affected in terms of its radiation characteristics. Much more

the lacquered side bars ensure that radiations in the angle range between 140 ° and a maximum of 180 ° of the LED strip are largely reflected towards the front, so that overall a radiation characteristic of almost 0 to 180 ° is observed with a maximum of the luminance in the range between 0 ° and 140 °, in each case based on a plane of symmetry, which passes through the center of the (cylindrical) housing shell and divides the housing shell in half.

As a result, the LED strip light can be operated with reduced energy compared to a tube of the same length and a plurality of LEDs arranged inside, with the same light output and at the same time improved homogeneous light emission. This also leads to an improved heat balance. The invention takes account of the fact that, according to an advantageous embodiment, the LED lighting means, a carrier and optionally at least one voltage converter are designed as an assembly which can be inserted into the housing. The voltage transformer or possibly the plurality of voltage transformers are usually arranged at the end of the carrier. The voltage converter is regularly found on a lower side of the carrier, whereas the LED illuminant or the one or more LED light strips are arranged on the upper side of the carrier.

The carrier is usually a circuit board. In order to realize the above-described topological arrangement, the LED illuminant may be formed as an SMD LED illuminant. In this case, the LED illuminant in question is thus immediately mounted and contacted on the surface of the carrier or the printed circuit board (SMD = Surface Mounted Device). In this way, the underside of the carrier is for example

the attachment of the one or more voltage transformers available.

However, since it is advantageous to work with the cylindrical and transparent housing shell and the housing insert, such a design is possible, but not preferred. Rather, the invention operates regularly so that the LED lighting means is designed as a longitudinally extended and correspondingly processed LED chip or LED light strip, which is received in the likewise elongated groove in the housing insert. This can be done by conventional attachment methods, for example by gluing in the groove in question, jamming, welding, etc ..

The voltage converter is usually an electronic voltage converter which converts the alternating voltage typically present for the supply of such fluorescent tubes into a low-voltage DC voltage for driving the LED illuminant or the one or more LED light strips. In this case, for example, two LED light strips can be realized, which together with a central contact path form the LED lighting means. However, most of the time, the invention works with a single integral and continuous LED light strip, which is adapted to the housing length. This light strip can be contacted on the support or the circuit board usually only with only two solder points in the already mentioned SMD technology. This has the consequence that significant cost savings in the production are observed in comparison to the situation that the circuit board or the carrier must be equipped with a variety of LEDs, as is pursued in the prior art according to WO 2010/063492 A2.

In addition, the diffuse and homogeneous luminous character of the LED luminous means according to the invention or of the at least one LED luminous strip is maintained over practically the entire service life. This is often not the case with fluorescent tubes having a multiplicity of LEDs arranged one behind the other in the longitudinal direction. For example, if one or more of these LEDs fail, immediately the overall visual impression is clouded by corresponding dark spots in the light image. This also changes the additionally provided litter layer nothing. As already explained, the housing is usually circular in cross section. In addition, it has proven useful if the housing is adapted to its size, design and length to variously used Leuchtstoffrhrenhren- housing, so that the arc tube according to the invention can replace such and previously often used fluorescent tubes directly. A further factor contributing to this is the fact that the housing is equipped in each case with connecting pieces which correspond to those of fluorescent tubes.

The LED illuminant or the at least one LED light strip divides the housing inside approximately in the middle. In this way, the carrier is brought to the metallic lower part in a thermally conductive connection. If required, it is additionally possible here to work with a heat-conducting material between the carrier and the metallic lower part. In any case, the metallic lower part acts as a heat sink for the wearer. The design is usually made so that the carrier rests on two longitudinal edges of the metal lower part. In the region of the longitudinal edges, for example, a respective groove can be provided in order to place and support the carrier.

It is understood that the LED illuminant or the LED luminous strip is thermally conductively connected to the carrier or the printed circuit board, which in turn is in heat-conducting contact with the metallic lower part or the housing insert to fill their described function as a heat sink can. Due to the overall low energy requirement, the metallic lower part or the housing insert suffices as a heat sink, especially since heat can be radiated over its entire surface. In fact, the metallic lower part has in cross-section over the already mentioned semicircular shape, so that over the entire length of this semicircular cylindrical surface radiated heat and can be delivered by convection. This is true even in the event that the arc tube is installed in a closed luminaire housing or otherwise thermally unfavorable. As a result, a fluorescent tube is provided, which can deliberately dispense with measures for optical light scattering due to the homogeneous and large-area light emission of the at least one LED light strip used. As a result, inevitably associated efficiency losses are avoided. At the same time the production is simplified because the attachment or expression of an additional litter layer is unnecessary.

At the same time a homogeneous and large-scale optical light impression is observed with a large radiation angle, which experiences no impairment in the course of its life. In addition, the emission characteristic of the LED strip used can of course be changed if necessary. For this purpose, it is within the scope of the invention that the LED light source is equipped with an upstream optics. As good as

If necessary, the transparent top can be colored to provide a specific lighting impression.

Alternatively, a desired spectrum can be realized electronically via the described color mixing in the generation of white light, so that measures for coloring the transparent upper part are not absolutely necessary. The use of generally harmless materials in the production allows a universal use of the arc tube according to the invention and at the same time allows a nationwide replacement of conventional fluorescent tubes. Here are the main benefits.

In the following the invention will be explained in more detail with reference to a drawing showing only one exemplary embodiment; 1 shows the arc tube according to the invention schematically in a perspective and partially with broken top and

Fig. 2 shows a cross section through the arc tube of FIG. 1, Fig. 3 is a light tube in cross section according to another embodiment and

Fig. 4 shows the article of FIG. 3 schematically. In the figures, a fluorescent tube is shown, which is equipped with an at least partially transparent housing 1, 2. According to the sectional view of FIG. 2, it can be seen that the housing 1, 2 in two parts with a transparent upper part 1 and a non-transparent or opaque

Lower part 2 is equipped. The lower part 2 is presently designed metallic and consists of aluminum.

The metallic lower part 2 may be made as an extruded profile or roll profile made of aluminum. By contrast, the transparent upper part 1 is regularly a plastic injection-molded part. Both housing parts 1, 2 are presently designed as semicircular cylindrical shells, which can be releasably coupled together in the region of their longitudinal edges 3. For coupling to the corresponding longitudinal edges 3 of both housing parts 1, 2 different connection methods are conceivable.

Thus, both housing parts 1, 2 can be coupled to each other via, for example, a thrust connection. In this case, the transparent upper part 1 may engage with tongues in the region of the longitudinal edges 3 in associated grooves in the metallic lower part 2 in a sliding manner. Also, a snap connection or generally a clamping connection or other releasable connections are possible at this point and are encompassed by the invention.

In each case end of the housing 1, 2 connecting pieces 4 are realized, which are equipped with pins 5. The respective connector 4 can be rotated as needed about a longitudinal axis of the illustrated arc tube to facilitate installation in an existing socket for conventional fluorescent tubes as their replacement. About the contact pins 5, the illustrated arc tube is operated with a supply voltage, which is generally a high alternating voltage.

This alternating high voltage at the contact pins 5 is converted into a voltage converter 6 in a low-voltage DC voltage. For this purpose, the voltage converter 6 typically operates electronically. With the help of

Low-voltage DC voltage, an LED light source 7 in the interior of the housing 1, 2 is supplied with electrical energy.

According to the invention, the LED illuminant 7 is at least one LED luminous strip 7 adapted to the housing length. In fact, according to the exemplary embodiment and corresponding to the representation in FIG. 1, two LED luminous strips 7 extending in the longitudinal extent of the housing 1, 2 are realized. which correspond in length to the entire housing length L or nearly equal to this length L. Between the two equidistantly arranged LED light strip 7 is still a contact strip or a contact track 9 is arranged. This is of course not mandatory, because even with a single continuous LED light strip 7 can be worked. In any case, the LED light strip 7 is integrally formed and continuous.

The LED illuminant 7 or the one or the two LED luminous strips 7 are arranged on an upper side of a carrier 8. The voltage converter 6 can be found on the underside of the carrier 8 in question. In fact, the voltage converter 6 may be arranged at the end of the housing 1, 2, in the present case being located in the interior of the connection piece 4.

The carrier 8 in the first exemplary embodiment is a printed circuit board. In the present case, the LED illuminant 7 is designed as a flat and one-piece LED illuminant 7 and can consequently be easily mounted on the upper side of the carrier or the printed circuit board 8 and contacted here. For this purpose, all conceivable attachment methods can be implemented, such as, for example, an adhesive connection of the LED light strip 7 to the printed circuit board 8. This makes the underside of the printed circuit board or of the carrier 8

for the attachment and placement of the voltage converter 6 as described.

Not shown is the possibility to equip the LED bulb 7 with an upstream optics. Also not shown are any thermally conductive materials or compounds, in the simplest case so-called thermal grease, with the help of a continuous flow of heat from the LED bulb 7 respectively the voltage converter 6 via the carrier respectively the printed circuit board 8 is provided up to the lower part 7 made of metal , In fact, this heat-conducting connection between the carrier or the printed circuit board 8 and the lower part 2 in the exemplary embodiment is provided by the fact that the carrier or the printed circuit board 8 spans the longitudinal edges 3 of the lower part 2 or rests on these longitudinal edges 3. As a result, the metallic lower part 2 can act as a heat sink and emit any resulting heat loss via its outwardly directed surface.

In the exemplary embodiment, the voltage converter 6, the carrier or the printed circuit board 8 and the LED lighting means 7 form a structural unit 6, 7, 8. This assembly 6, 7, 8 can be used in total in the housing 1, 2. This facilitates assembly and assembly and allows for particular cost benefits. In addition, the design is such that the carrier 8 divides the housing 1, 2 in the middle approximately in the interior. The embodiment of FIGS. 3 and 4 is similar to that of FIGS. 1 and 2 constructed. It can be seen that the LED luminous strip or the LED illuminant 7 is in each case arranged centrally in the interior of the housing 1, 2 on a plane of symmetry S, which divides the housing 1, 2 into two matching longitudinal halves. In the variant of FIGS. 3 and 4 is

the housing 1, 2 again designed in two parts, here with a housing cover 2 and a housing insert. 1 D. h., The two housing parts 1, 2 are not formed in this case as upper part 1 and lower part 2 but shell 2 and insert 1. Within the scope of this variant, the housing insert 1 at the same time assumes the function of the carrier 8 already described above. That is to say, the carrier or the printed circuit board 8 may be integrated into the housing insert 1 in question. The same applies to the voltage converter 6, and that at least the end of the housing 1, 2. The housing shell 2 is designed in the context of the embodiment of FIGS. 3 and 4 cylindrical and encloses the housing insert 1 completely. The housing shell 1 may be transparent or opaque. As in the case of the transparent upper part 1 already described above, in this case too it is a plastic injection-molded part. Embedded in the plastic scattering particles may provide if necessary for the necessary opacity of the case 2.

It can be seen that the housing insert 1 or the carrier 8 has an elongated groove 11. The groove 1 1 is symmetrical in comparison to the symmetry plane S and arranged centrally within the housing shell 2. In the groove 1 1 of the LED light strip 7 is added. Side of the groove 1 1 extend two side bars 10, which include an overall obtuse angle between them. Like the elongated groove 1 1, the side bars 10 are also elongated and moreover arranged symmetrically in comparison to the plane of symmetry S. In addition, the side bars 10 have a painted, at least reflective surface for emitted by the LED light source 7 light. In this way, experience light rays emanating from the LED light strip 7

and emitted, for example, in the angular range between about 140 ° and 180 °, a reflection on the two-sided (painted) side bars 10. Thus, the rays are reflected more or less pronounced in the forward direction of the side bars 10, so that the light emission of the arc tube according to the invention a Focusing in the forward direction.

Claims

claims:

1 . Light tube, with an at least partially transparent housing (1, 2), and with at least one in the housing (1, 2) arranged LED lighting means (7), characterized in that the LED lighting means (7) as at least one to the housing length ( L) adapted one-piece and continuous LED light strip (7) is formed.

2. arc tube according to claim 1, characterized in that the LED lighting means (7), a support (8) and optionally at least one voltage converter (6) as in the housing (1, 2) usable assembly (6, 7, 8) are formed.

3. arc tube according to claim 2, characterized in that the voltage converter (6) end of the carrier (8) is arranged.

4. arc tube according to one of claims 1 to 3, characterized in that the carrier (8) is designed as a printed circuit board (8).

5. Luminous tube according to one of claims 1 to 4, characterized marked, that the LED lighting means (7) has two LED light strips (7) with a central

Contact track (9).

6. arc tube according to one of claims 1 to 5, characterized in that the housing (1, 2) is circular in cross-section, wherein the LED illuminant (7) divides the housing (1, 2) in the center approximately in the middle.

7. Tube according to one of claims 1 to 6, characterized in that the housing (1, 2) in two parts with a metallic lower part (2) and a transparent upper part (1) is formed.

8. arc tube according to claim 7, characterized in that the two housing parts (1, 2) are detachably coupled to each other via, for example, a thrust connection, a latching connection, a clamping connection, etc.

9. Tube according to one of claims 7 or 8, characterized in that the lower part (2) of aluminum and / or plastic and the

Upper part (1) are made of transparent plastic.

10. Tube according to one of claims 1 to 9, characterized in that the LED lighting means (7) has an upstream optics.

1 1. Illuminating tube according to one of claims 7 to 10, characterized in that the housing (1, 2) is formed in two parts with a housing insert (1) and a housing shell (2).

12. Tube according to claim 1 1, characterized in that the housing shell (2) is cylindrical and surrounds the opposite central housing insert (1) in the center.

13. arc tube according to one of claims 1 to 12, characterized in that the carrier (8) has a central groove (1 1) for receiving the LED light strip (7).

14. Tube according to one of claims 1 to 13, characterized in that the carrier (8) arranged on both sides of the LED light strip (7)

Side webs (10), which include an obtuse angle between them.

15. Tube according to claim 14, characterized in that the two side webs (10) have a reflective surface.