EP3056805B2 - Elongated optic for led module - Google Patents

Description

The invention generally relates to a lamp, in particular a linear lamp, comprising an optic that can be connected to a mounting body, comprising a plurality of individual optics and a plurality of LED modules, each of which comprises LEDs, the individual optics being arranged in an optically optimized manner in the installation position in relation to the LEDs of the LED modules. to realize a desired light distribution curve for a visual task. In particular, the invention thus relates to a long lamp with long LED modules and long optical systems.

Long in the sense of this invention is a light that is longer than 560 to 600 mm; the width is usually much smaller at 150 to 200 mm. Individual optics are several optics provided in the optics, which are assigned to the individual LEDs in the installation position and with these, i.e. preferably arranged in the optical axis of the LED, realize a highly efficient light distribution curve for the realization of the respective visual task. The individual optics are preferably designed as collimator lenses in the optics.

State of the art

In previous lights, LED modules are fixed to a mounting body, which is also used for thermal cooling, i.e. as a heat sink. The mostly different linear expansion of the optical system, the LED module, usually consisting of a first plastic with a first coefficient of thermal expansion, and the mounting body, usually consisting of metal or another plastic, but in any case with a coefficient of thermal expansion that differs from the first coefficient of thermal expansion, to be matched as precisely as possible , so that lighting technology that is highly efficient due to heating can also be provided during operation. These are lights that have a light distribution curve (LVK) desired for the respective visual or work task without lateral displacement of the axes of the light sources, in particular individual LEDs, to the associated optical system, preferably individual lenses, particularly preferably collimator lenses, caused by heating. The lenses or the optical system should therefore be positioned at exactly the desired position in relation to the light source, in particular the individual LEDs of an LED grid, regardless of different material pairings of the materials used for the optical system and the assembly body.

Adapted to the current maximum length of LED modules, there are optics with individual lenses with a maximum length of approx. 600 mm, in which a suitable, central positioning means that the plastic optic can still expand by a maximum of 1 mm relative to the LED circuit board can be compensated well.

Longer optics are desirable, particularly to reduce costs associated with the assembly and manufacture of linear lights, strip lights and the like, e.g., by extrusion. With longer optics, however, there is the problem of imprecise positioning of the optical system with a plurality of individual lenses spaced apart from one another in relation to the optical axis of the associated LEDs on an LED circuit board when it is heated. Heat causes an expansion, in particular a longitudinal expansion of the optics and thus a displacement of the lenses from the desired positions that coincide with the optical axes of the individual LEDs, so that the light distribution curves are no longer highly efficient and are therefore negatively influenced. In addition, the glare control, which is particularly relevant for workplaces to avoid excessive luminance above a viewing angle of 65 degrees in relation to the horizontal, is negatively influenced, which is intended to prevent a direct view of individual lamps.

In order to be able to implement longer optics with individual lenses, usually up to a length of approx. 1500mm with simple means, a suitable possibility must be provided to minimize the linear expansion of plastic optics in relation to those of the LEDs or to adapt them to them.

DE 10 2010 016 385 A1 describes a lighting arrangement with a heat sink, at least one light-emitting diode mounted on the heat sink and anti-dazzle lighting optics mounted in front of the light-emitting diodes, the lighting optics comprising a grooved, translucent, truncated cone-shaped or essentially trapezoidal anti-glare body in cross-section, the end face of the anti-glare body with a smaller diameter having a Having recess and wherein the anti-glare body is arranged with the recess in front of the lamp that it is arranged off-axis to the truncated cone axis of the anti-glare body. In this case, several anti-glare bodies can also be integrated linearly to form an optical system and attached in front of the associated light-emitting diodes mounted on the heat sink. A certain displacement of the optics compared to the circuit board due to different thermal expansion is accepted.

Similar lights are also from the U.S. 2011/007516 A1 , CN 201 242 134 Y , U.S. 2014/168975 A1 as well as the DE 10 2013 203912 A1 known. A lamp of a different kind is from the EP 2 827 053 A1 known.

Technical problem (task)

Based on this prior art, the invention addresses the technical problem of at least partially avoiding these disadvantages and, in particular, of ensuring precise positioning of the individual LEDs of an LED module with respect to the individual optical lenses at all times, even with long lights.

The invention is therefore concerned with that The problem of coordinating the mostly different linear expansions of optical systems, LED modules and assembly bodies in such a way that the efficiency of the luminaires is not negatively influenced when they heat up. The invention is therefore intended to provide long, photometrically highly efficient luminaires for the realization of the light distribution curves required for the visual task with simultaneous glare control.

invention

According to the invention, this object is essentially already achieved in the case of a linear luminaire or a light line system in that several LED modules are accommodated by the optics and are connected to it without a direct connection to the luminaire housing or the assembly body. Furthermore, the optics have a multiple of the length of an LED module. This achieves a "floating" mounting of the LED modules on the otherwise rigid assembly body to compensate for thermal expansion during operation. The invention takes a completely new approach insofar as it now assigns the LED module to the optics and no longer to the assembly body or the luminaire housing. Each of the LED modules includes a plate-shaped plastic carrier with an applied copper layer.

According to the invention, the LED circuit board of the LED module, i.e. the plate-shaped carrier element with the LEDs applied to it adapted to the application and extending collinearly along a common longitudinal axis, is no longer assigned to a rigid housing or heat sink, but to the optics. According to the invention, the connection is thus realized between the optics and the LED. The floating mounting according to the invention ensures that the LEDs of the LED modules are always centered in relation to the optics. If the optics expand when heated, the LED module moves with it and the centering of the LEDs to the respective lens is still guaranteed.

According to the invention, the optics are designed to accommodate the LED modules or to be connected to them. This can be done, for example, by providing receptacles or receptacle slots on the optics, which extend in the longitudinal direction of the luminaire in the installed position and into which the long sides of the LED circuit board of the LED module can be inserted or snapped in such a way that the optics in the installed position Radiation direction thus extends in the direction of the optical axis of the individual LEDs like a bridge over these LEDs, in such a way that the highest optical efficiency can be achieved at any time.

In the embodiment that is preferred in terms of manufacturing technology, the optics are designed as a one-piece injection molded or extrusion injection molded part.

The optical efficiency, in particular the degree of reflection, can be further improved if the materials of the optics and the LED modules have the same or a very similar coefficient of thermal expansion.

According to the invention, the optics have a multiple of the length of the LED modules, in particular 3 times, so that 3 LED modules are arranged collinear to one another in the direction of longitudinal extent and one behind the other in the optics.

During the development of the invention, it has been shown that many LED modules currently available on the market provide the cooling capacity of the LED module with the copper layer applied to the plate-shaped plastic carrier with sufficient self-cooling capacity that no additional heat sinks are required, in particular no direct connection of the LED circuit board with the mounting body is necessary. This is particularly possible with mid-power LED modules with luminous fluxes of 1000 to 2000 lm (lumen), with the individual LEDs realizing luminous fluxes of 30 - 50 lm. By combining several of these LED modules in the arrangement according to the invention, standard lights with luminous fluxes of 4000 to 6000 lumens that can be individually adapted to the respective visual task can be implemented, in particular for the workplace area.

Such lights can be used, for example, in offices, in corridors, e.g. installed in light channels, but also in shops or in the retail sector and even as light strips in production or factory buildings.

The LED module is preferably connected to or fixed in a long lens. The optics are preferably manufactured in an extrusion injection molding process and the circuit board of the LED module by e.g. by laminating preferably glass fiber reinforced plastics, which are particularly preferably laminated on top of one another with alternating fiber directions, incorporating the conductor tracks and any other electronic components to form the final module or its "substrate" on which the LEDs can be attached.

In order to ensure precise positioning of the optics in relation to the individual LEDs of the LED modules under all operating conditions, at least one centering means is preferably provided between the optics and the LED module for connecting the LED module to the optics, eg in the form of a snap hook or a centering pin. If the optics expand due to thermal effects during operation, the LED module is taken along by this centering means to the same extent, so that each LED continues to be precisely centered in the desired optical position with respect to the optics or an optical element, such as one lens formed in optics.

Preferably, several, e.g. approx. 560 mm long LED modules according to the Zhaga standard are used or accommodated in optics that are twice, three times or even four times as long.

In the preferred embodiment, the optics are designed to accommodate the LED modules, e.g. B. by extending in the longitudinal direction Receiving grooves optically optimized spaced apart from the lenses spanning the LEDs of the LED module in a dome-like manner in the installed position.

In the preferred embodiment, the material of the LED module or the carrier plate (substrate) of the LED module and the optics have a similar or the same coefficient of thermal expansion. Plastics that are highly effective in terms of light technology, in particular glassy plastics, have proven to be preferred materials for the manufacture of the optics, in particular PMMA with a refractive index of 1.49 and a transmittance of 92%, but also PC.

Due to the design according to the invention, the mounting body only functions to stiffen the lamp, closes off the optics at the rear and offers space for electrical and/or electronic components, in particular an operating device and attachment points. It therefore no longer has to provide the function of the heat sink for cooling the LEDs and can in this respect be designed in a much more filigree manner, in particular taking a back seat in terms of design. In this respect, in a particularly preferred embodiment of the invention, additional heat sinks can also be completely dispensed with.

A centering element can be provided between the optics and the LED module. Due to the combination of the floating mounting of the components and the centering element, the LED module can thus move independently of the optics and also of the optical lenses in the event of thermal expansion in relation to the centering point. This centering element thus causes the two components to be fixed in position in relation to one another. The centering element is preferably arranged centrally between the LED module and the optics, with the result that the linear expansion that occurs when it is heated is halved.

In the preferred embodiment, the centering comprises a mandrel (pin) or snap hook on a component which, in the installed position, engages in the complementarily formed joining partner or the counter-element in an operatively connecting manner.

The inventive design also enables the production and use of long optics for the first time, which significantly reduces the assembly work, especially for linear lights and light strips, because fewer components have to be assembled and screwed, which can be problematic especially for overhead assembly.

In a preferred further development, the lamp and in particular the optics with the integrated LED module(s) are sealed by means of seals in order to achieve high degrees of protection. In the preferred embodiment, this takes place through a preferably circumferential sealing channel between the optics and the LED module for receiving a seal, e.g. comprising a sealing cord or a sealing foam. But full-surface bonding is also possible.)

The wiring of the LED circuit boards is preferably carried out from the rear by means of connecting terminals applied on the rear.

The circuit boards of the LED module preferably include a glass fiber reinforced carrier material, in particular FR4, CEM3.

The lamp body is preferably made of heat-conducting plastic in order to be able to better dissipate the heat that occurs, but it can also be made of metal.

The core of the invention thus lies in the fact that the LED circuit board of the LED module is no longer mounted on the mounting body, but on the optics, which is preferably done by means of retaining pins or other retaining elements. Thus, even with longer optics, the position of the lenses of the optics in relation to the LEDs no longer changes, so that the optics are always highly efficient, self-regulating, even when heated. The invention thus achieves particularly accurate imaging with simple means, ie the optically optimized positioning of each individual lens in relation to the associated LED.

Fig. 1

einen schematischen Längsschnitt einer ersten Ausführungsform einer erfindungsgemäßen Leuchte; und

Fig. 2

einen vergrößerten schematischen Längsschnitt einer zweiten Ausführungsform einer erfindungsgemäßen Leuchte.

Further details, advantages and features of the invention can be found in the following part of the description, in that two exemplary embodiments of the device according to the invention are explained in more detail using two drawings. Show it:

1

a schematic longitudinal section of a first embodiment of a lamp according to the invention; and

2

an enlarged schematic longitudinal section of a second embodiment of a lamp according to the invention.

Parts that are the same or have the same effect are provided with the same reference symbols.

Accordingly, the elongated linear luminaire essentially consists of a mounting body 2 on the upper side in the figures, which defines an upper part that extends horizontally in the figures, which, with a transverse to the upper plane defined by this upper part, has a circumferential edge web that protrudes transversely downwards at the edge 2a.

An operating device is placed on top of the mounting body 2 , which, however, can also be integrated into the mounting body 2 in an alternative embodiment.

On the mounting body 2 or on its circumferential edge web 2a, a one-piece and transparent optic 6 is arranged that is complementary to the geometry and to the structure of the mounting body 2 in the present embodiments has the same length as the mounting body and in this respect also at the edge an edge web running transversely upwards to the optical plane 6a, so that in the installed position the edge webs 2a, 6a butt against one another without transition and thus form a closed, elongated box-shaped lamp body.

Integrated into the optics, i.e. formed in one piece with it, are optical lenses 6b arranged equidistantly from one another in the longitudinal direction, which are essentially parabolic in cross section and whose vertices are each optically optimized and arranged exactly below the optical axis of the corresponding LEDs 8a on two LED modules 8 are.

Two rod-shaped centering elements 10 are arranged approximately in the middle between the LED module 8 and the optics 6 , which fix the position of the optical lenses 6b precisely relative to the optical axes of the LEDs 8a of the two LED modules 8 .

Electrical connecting elements 12 are arranged on the upper end faces of the oblong rectangular LED modules 8 and are designed to connect the LED module to the operating device 4 and/or an LED module 8 to an adjacent LED module.

the figure 2 shows a schematic longitudinal section of a basically similarly designed linear luminaire, in which a total of four of the elongate LED modules 8 are accommodated collinearly with one another in the optics 14 so as to be longitudinally displaceable in order to achieve a length of, for example, 2400 mm.

The subject matter of the present invention results not only from the subject matter of the individual patent claims, but from the combination of the individual patent claims with one another. All information and features disclosed in the documents - including the summary - in particular the spatial configuration shown in the drawings are claimed to be essential to the invention insofar as they are new compared to the prior art, individually or in combination.

Reference List

2

assembly body

2a

edge bar

4

control gear

6

optics

6a

edge bar

6b

lens

8th

LED module

8a

LEDs

10

centering element

12

fastener

14

optics

Claims (4)

1. Strip light, comprising several LED-modules each comprising LEDs, and comprising an optical system (6) connectable to a mounting body (2) and comprising several individual optical systems which, in the installed position, are arranged in an optically optimized manner with respect to the LEDs (8a) of the LED modules (8) to realize a desired light distribution curve for a vision task, wherein each LED module comprises a plate-like plastic carrier with deposited copper layer, characterized in that several LED modules are housed by the optical system (6) and are connected to the optical system without a direct connection to the mounting body and that the optical system (6) is several times longer than the length of an LED module (8).
2. Light according to claim 1 or 2, characterized in that the optical system is designed for housing the LED modules (8) in a longitudinally displaceable manner.
3. Light according to claim 3, characterized in that between the optical system and at least one of the LED modules (8) at least one centering element is provided.
4. Light according to claim 4, characterized in that the centering element comprises a latching means or a connecting pin.

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