Light fixture comprising at least one LED module

Abstract

Luminaire comprising at least one LED module (M, M') which comprises: - a carrier, - a first group (G1, G1') and a second group (G2, G2') of LED chips arranged on the carrier, and - a uniform layer (T, T') covering all LED chips, which has at least one contains a color conversion agent that converts the spectrum of the LEDs of one group (G1; G1 ) into a spectrum with a different dominant wavelength, wherein: - each group (G1, G2; G1', G2') includes at least one, preferably several, LED chips, - the LED chips of a group (G1, G2; G1', G2') are connected in series and can be powered from the same electrical supply, - the LED chips of different groups (G1, G2; G1', G2') independently of each other starting from can be supplied by different electrical power supplies, and - the luminous flux of the second group (G2, G2') of LED chips is in a range of 1%-25% of the luminous flux of the LED chips of the first group (G1, G1') and / or the number of LED chips of the second group (G2, G2') corresponds to 1%-25% of the number of LED chips of the first group (G1, G1'), wherein the luminaire has an independent electrical supply for each group of LED chips, wherein at least one group of LED chips can be operated from a first electrical supply and at least one group of LED chips can be operated from a second electrical supply independent of the first electrical supply, the light is an LED-based emergency light and features: - as the second electrical supply, an energy storage system - a connection for connecting the light to a primary electrical supply and - a detection circuit designed to detect an interruption in the primary electrical supply, wherein the luminaire is configured to operate at least the LED chips of one group of the at least one LED module when the first electrical supply is applied and, upon detection of an interruption of the first electrical supply by the detection circuit, to operate at least the LED chips of another group, and wherein the radiation emitted by the LED chips of the second group (G2, G2') is not converted by the at least one color conversion agent in the covering layer (T, T').

Description

[0001] The present invention relates to a luminaire comprising at least one LED module.

[0002] LED modules with at least one LED chip are used in many areas of lighting technology. In recent years, LED modules have gained a foothold in almost all areas of lighting technology and are increasingly being used, for example, due to their energy efficiency. Since their comparatively low power consumption is advantageous for use in many areas, LED modules are also used, for example, when the available electrical power for lighting operation is limited. An example of this is emergency lighting, which is used for lighting in the event of a power failure.

[0003] Another advantage of LED modules is that a larger number of LED chips can be mounted on a relatively small LED module. This allows multiple LED chips to be combined and achieve higher light output in a relatively small space.

[0004] US 2005 / 0117334 A1 discloses an LED module which, for generating white light, comprises at least three LED chips each emitting in a different color and a phosphor which absorbs the light of two of the LED chips and emits light of a different wavelength.

[0005] JP 2009-158872 A discloses an LED module comprising numerous LED chips grouped in several groups, each connected in series.

[0006] DE 102010061801 A1 discloses an LED module comprising LED chips of a first group and LED chips of a second group as well as an encapsulation layer comprising a color conversion material arranged thereon, wherein the amount of the color conversion material on the LED chips of the two groups is different in each case.

[0007] JP 2012-14897 A discloses an LED module with emergency lighting function, wherein individual LEDs are mounted on a circuit board.

[0008] US 2012 / 011 2236 A1 discloses an LED chip arrangement which is mounted directly on a printed circuit board, wherein the LEDs are embedded in a layer covering the latter, which layer may contain a dye.

[0009] The present invention now sets itself the task of providing LED modules, for example, for use in LED luminaires or emergency lighting luminaires, which allow for reliable operation in a simple manner while simultaneously reducing the number of LED modules used. This object is achieved by the luminaire according to independent claim 1, which has at least one LED module.

[0010] In one embodiment, the invention provides a luminaire comprising at least one LED module, which comprises: a carrier, a first group and a second group of LED chips arranged on the carrier, optionally one or more further groups of LED chips, and a uniform layer covering all of the LED chips, which layer contains at least one color conversion substance that converts the spectrum of the LEDs in one group into a spectrum with a different dominant wavelength. Each group comprises at least one, preferably several, LED chips. The LED chips in one group are connected in series and can be supplied from the same electrical supply. The LED chips in different groups can be supplied independently of one another, from different electrical supplies.The light output of the second group of LED chips lies in a range of 1%-25% of the light output of the LED chips in the first group and / or the number of LED chips in the second group corresponds to 1%-25% of the number of LED chips in the first group. The luminaire has an independent electrical supply for each group of LED chips, wherein at least one group of LED chips is operable from a first electrical supply and at least one group of LED chips is operable from a second electrical supply independent of the first electrical supply. The luminaire is an LED-based emergency light and has: as the second electrical supply, an energy storage device, a terminal for connecting the luminaire to a first electrical supply, and a detection circuit configured to detect an interruption in the first electrical supply.The luminaire is configured to operate at least the LED chips of one group of the at least one LED module when the first electrical supply is applied, and to operate at least the LED chips of another group when an interruption of the first electrical supply is detected by the detection circuit. The radiation emitted by the LED chips of the second group is not converted by the at least one color conversion substance in the covering layer.

[0011] The covering layer can be applied over / on the LED chips, in particular in a “dam-and-fill” or by a dispensing process, e.g. as a ball head or globe top.

[0012] The color conversion substance may contain a phosphor.

[0013] The radiation emitted by the LED chips of the first and second groups can be light in the visible spectrum.

[0014] The LED chips of the second group can emit radiation preferably in the red spectrum. The radiation emitted by the LED chips of the second group is not converted by the at least one color conversion substance in the covering layer. This means that only the spectrum emitted by the first group is converted in this case.

[0015] The light output of the second group of LED chips is in a range of 1%-25%, and can preferably be in a range of 5%-10%, of the light output of the LED chips in the first group. The number of LED chips in the second group corresponds to 1%-25%, and can preferably be in a range of 5%-15%, of the number of LED chips in the first group.

[0016] The LED module can have at least one first conductor for connecting the LED chips of the first group to a first terminal for connecting the first group to a first electrical supply and at least one second conductor for connecting the LED chips of the second group to a second terminal for connecting the second group to a second electrical supply. The conductors can preferably be arranged on the carrier. The conductors can also lead beyond the actual module carrier and thus be connected, for example, to conductors of other modules. The terminals can also be located outside the LED module carrier, but are preferably arranged on the carrier. The conductors can be at least partially covered by the covering layer.

[0017] The conductors can also be arranged at least partially on the side of the carrier on which the LED chips are arranged. However, the conductors can also be arranged at least partially on the side of the carrier on which the LED chips are not arranged.

[0018] The terminals on the carrier can be arranged so that they face each other. In particular, the terminals can be arranged on different sides of the LED module. The terminals can also be arranged on different sides of the carrier. For example, some of the terminals can be arranged on the side of the carrier where the LED chips of a group are located, while another part of the terminals can be located on a different side of the carrier. The terminals can be arranged parallel to each other. The terminals can be provided on one side of the LED module.

[0019] The carrier can be a printed circuit board, e.g. a single-sided or double-sided PCB, or an SMD carrier (Surface-Mounted Device carrier).

[0020] The invention provides an LED luminaire comprising at least one LED module as described above and an independent electrical supply for each group of LED chips.

[0021] The electrical supplies of the LED luminaire can be designed as voltage supplies in such a way that only one group of LED chips is operated at the same time.

[0022] According to the invention, the luminaire is an LED-based emergency light, wherein at least one group of LED chips can be operated from a first electrical supply / mains voltage and at least one group of LED chips can be operated from a second electrical supply / voltage supply independent of the first electrical supply / mains voltage. It should be understood that an electrical supply can be provided from a voltage source or current source, with one group being supplied from a voltage source and another group being supplied from a current source. If there are multiple groups, an electrical supply can also be provided for each group.

[0023] The LED-based emergency light comprises: as the second electrical supply an energy store, preferably a battery or an accumulator, a connection for connecting the emergency light to a first electrical supply, in particular a supply voltage or mains voltage, and a detection circuit which is configured to detect an interruption of the first electrical supply, wherein the emergency light is configured to operate at least the LED chips of the first group of the at least one LED module when the first electrical supply is applied and to operate at least the LED chips of the second group when an interruption of the first electrical supply is detected by the detection circuit.

[0024] The emergency light can operate the second group from the energy storage unit.

[0025] The emergency light can be configured to operate one LED module as described above and another LED module, wherein the other LED module has only one, in particular a single, group of LED chips. The emergency lighting device can operate the other LED module and / or the LED chips of the first group of the LED module from the first electrical supply, e.g. when the supply voltage is applied. The emergency light can operate the LED chips of the second group from the second electrical supply, e.g. in the event of a supply voltage failure, and in particular only the second group. The LED chips of the LED module and the LED chips of the other LED module can be arranged identically, preferably in the same predetermined grid. The number of LED chips in the modules can correspond or be the same.

[0026] A combination of an LED module as described above with another LED module can be provided. The other LED module can have only a single group of LED chips, whereby the LED chips of both modules can be arranged in the same predetermined grid. The number of LED chips in the modules can be the same or the same.

[0027] The combination can be further combined with a luminaire, i.e., an emergency luminaire, as described above. It should be understood that the respective luminaire / emergency luminaire can also have only a single LED module of each type, i.e., in particular, it can have only one LED module, as described above.

[0028] The invention will now be described with reference to the figures, each of which shows partial aspects of the luminaire according to the invention. Herein: Fig. 1 shows an exemplary LED module according to the invention according to a first embodiment, Fig. 2 schematically shows a possible connection of the LED chips with conductors mounted on the LED module according to the first embodiment, Fig. 3 schematically shows a second embodiment of an LED module according to the invention, Fig. 4 schematically shows a possible connection of the LED chips with conductors mounted on the LED module according to the second embodiment, Fig. 5 schematically shows a luminaire, in particular an emergency luminaire.

[0029] The present invention therefore relates to a luminaire comprising at least one LED module with at least two LED chips, wherein the LED chips present on an LED module M, M' can preferably be divided into two or more groups G1, G2, G1', G2' according to the invention. Overall, the LED module M, M' is manufactured using known manufacturing processes. It comprises, for example, a printed circuit board (e.g., PCB) as a carrier or an SMD carrier.

[0030] Fig. 1 shows an LED module M of a first embodiment, in which the LED chips of a first group G1 are depicted as squares and the LED chips of a second group G2 are depicted as circles. Furthermore, conductors L1, L2 are depicted, which serve to supply the respective LED groups G1, G2. A covering layer T is delimited by a barrier B. Terminals A1 are provided for connecting the first group G1 to a first electrical supply, while terminals A2 are provided for connecting the second group G2 to a second electrical supply.

[0031] Fig. 2 shows one possibility how the LED chips of the different groups G1, G2 of the LED module M are Fig. 1 are connected to the respective conductors L1, L2 and thus to the terminals A1, A2 for the respective group G1, G2. The LED module is in comparison to Fig. 1 is shown rotated 90° counterclockwise. Here, terminals A1 represent the connections for the LED chips for the first group G1, while terminals A2 represent the connections for the second LED chip group G2. The connections between conductors L1, L2 and the LED chips of groups G1, G2 are designated V. In particular, the LED chips can be connected in series. In the example shown, terminals A1, A2 for the LED chip groups G1, G2 are located on the same side of the LED module.

[0032] In Fig. 3, the terminals A1' and A2' of the module M' are arranged parallel to one side of the module. Here, too, two groups G1', G2' of LED chips are shown, with the first LED chip group G1' being represented by circles and the second group G2' by squares. Conductors L1', L2' are also shown, each connecting an LED group G1', G2' to the respective terminals A1', A2'. In particular, the conductors L1', L2' are shaped differently than in Fig. 1 and the terminals A1', A2' are now located (diametrically) opposite each other on opposite sides of the LED module M'.

[0033] Fig. 4 shows how the LED chips of the respective group G1', G2' are connected to the terminals A1' and A2' of the LED module M' from Fig. 3 via the conductors L1' and L2' and the connections V'. The LED module is in comparison to Fig. 3 shown rotated 90° counterclockwise.

[0034] For the sake of clarity, not all similar components are provided with reference symbols in the figures.

[0035] Fig. 5 schematically shows a luminaire which is an emergency light N. The emergency light N can be connected to a first electrical supply, e.g. a supply or mains voltage, via a connection A. The emergency light further comprises an energy storage device C which represents a second electrical supply. The emergency light N additionally comprises a detection circuit E which can detect an interruption of the first electrical supply. The emergency light N further operates a module M (or M') which, depending on the state of the first electrical supply detected by the detection circuit E, is supplied either from the first electrical supply or from the second electrical supply, here e.g. from the energy storage device C.

[0036] The LED module M, M' according to the invention is particularly designed such that each group G1, G2, G1', G2' of LED chips can be operated separately from at least one electrical voltage / current supply. In the figures, the LED chips of a first group G1, G1' are schematically represented as circles, while the LED chips of a second group G2, G2' are represented as squares.

[0037] However, it should be understood that the LED chips do not actually have to differ in their structural design and can have different shapes. Cost-effective SMD LED chips, in particular, can be used as LED chips.

[0038] The LED modules M, M' according to the invention comprise a first group G1, G1' of LED chips and a second group G2, G2' of LED chips, which are arranged beneath a uniform covering layer T, T', for example a uniform encapsulating compound. The covering layer T, T' comprises, in particular, a color conversion substance, for example at least one phosphor, which partially converts the radiation emitted by the LED chips. It can be provided that the color conversion substance converts the radiation emitted by the LED chips of one or more groups G1, G2, G1', G2' into radiation that lies in a different spectrum than the radiation emitted by the LED chips. Furthermore, it can be provided that the color conversion substance consists of several components, e.g., several phosphors.

[0039] It can be provided that a first group G1, G1' of LED chips is only operated when another group G2, G2' of LED chips is not operated. This is possible, in particular, if the LED chips belonging to the different groups G1, G2, G1', G2' can be powered by independent electrical supplies. For example, it is possible to power one group of LED chips from a first electrical supply, e.g., an AC voltage / current source, and another group of LED chips from a second electrical supply, e.g., a DC voltage / current source.

[0040] Preferably, the two groups G1, G2, G1', G2' of LED chips emit radiation in one spectrum, wherein the radiation emitted by the LED chips of one of the two groups is then partially or completely converted by the color conversion substance contained in the covering layer T, T'. Of course, it can be provided that the emitted radiation, e.g., in the visible spectrum, of each LED chip is converted by the color conversion substance. However, according to the invention, the color conversion substance only converts the radiation of one group G1, G1' / G2, G2' or of specific LED chips.

[0041] Conversion by the color conversion substance is understood to mean, in particular, the conversion of radiation of one dominant wavelength into radiation of another dominant wavelength.

[0042] The covering layer T, T' can be applied over / on the LED chips using known methods. For example, the covering layer can be applied over / on the LED chips using a "dam-and-fill" process or by dispensing, e.g., as ball-head / globe tops.

[0043] A "dam-and-fill" process is understood to mean a process in which a barrier B, B' is formed around the LED chips, in particular on the LED module M, M', which prevents the flow of an applied covering layer or a potting compound beyond the barrier B, B'.

[0044] The LED module M, M' designed in this way can now be used especially in LED luminaires that have independent power supplies for each LED chip group G1, G2, G1', G2'. This allows two different lighting modes to be set with a single LED module M, M'.

[0045] This is advantageous, for example, in situations where light of one spectrum is to be emitted in one situation, while light of a different spectrum is to be emitted in another situation. Furthermore, the light output emitted by the LED module M, M' can be varied by specifically controlling different groups G1, G2, G1', G2'. For example, it is conceivable that the LED modules M, M' according to the invention could be used in vehicles, such as airplanes or trains, where, for example, reading lighting or rest lighting is to be provided at a seat.Here, a larger number of LED chips can be arranged in a first group G1, G1', which is controlled for normal lighting, while a relatively smaller number of LED chips can be arranged in a second group G2, G2', which is then selectively controlled when a sleep mode / reading lighting mode is to be provided, for example upon interaction of a user.

[0046] According to the invention, the LED module is used in an emergency light N (see Fig.5), which, for example, switches from normal operation to emergency lighting operation in the event of a mains voltage failure. Here, the LED module M, M' according to the invention can reduce manufacturing costs, since now only one type of LED module needs to be installed. The emergency light luminaire N can thus control a first group G1, G1' of LED chips of the LED module M, M' in normal lighting operation, while a second LED chip group G2, G2' of the same module M, M' is controlled in emergency lighting operation. For example, in emergency lighting operation, the second group G2, G2' of LED chips can therefore preferably be supplied with a DC voltage from an energy storage device C (for example a battery and / or an accumulator) in emergency lighting operation. In normal lighting operation, the LED module is supplied with a supply voltage, in particular a mains / AC voltage, from a connection A.

[0047] The light output of the second LED chip group G2, G2', e.g. an emergency light LED chip group, can be in a range of 1% to 25%, preferably in a range of 5% to 10%, of the light output of the first LED chip group G1, G1', e.g. a normal light LED chip group.

[0048] Overall, the LED chips of the LED module M, M' can be distributed across different groups. However, a reduction in the emitted light output can preferably be achieved by having more LED chips in one group than in another LED group. For example, with two groups G1, G2, G1', G2', a reduction in light output is achieved by the number of LED chips in the first group G1, G1' being only 1% to 25%, or preferably 5% to 15%, of the number of LED chips in the second group G2, G2'. This can also be used, for example, to reduce the light output to the emergency lighting power level by switching from the first group G1, G1' to the second group G2, G2' of LED chips during emergency lighting operation, which is then operated by the emergency light N.

[0049] This allows the power consumption of the LED module M, M' to be reduced, of course, with the reduction in the number of LED chips to be operated already contributing to this reduction. By selecting different LED chips for each group, the required operating power can be further reduced. For example, more energy-efficient LED chips can be used in the second group than in the first.

[0050] Overall, it is of course possible to provide multiple groups and thus achieve a staggered light output. For example, with three LED groups, the LED chips of all three groups could initially be operated in normal light mode, while different modes can be selected to deactivate / activate individual LED groups. If the operation of an LED group is designated as "1" and the switching off of an LED group is designated as "0", eight operating modes are possible with just three LED groups: 1, 1, 1; 1, 1, 0; 1, 0, 1; 1, 0, 0; 0, 1, 1; 0, 1, 0; 0, 0, 1; and 0, 0, 0.

[0051] These operating modes can, for example, also be selected depending on the available power or over time. For example, one operating mode can be selected when more power can / should be drawn from an energy storage device (e.g. energy storage device C), while another operating mode is selected when a certain threshold is reached. Accordingly, several thresholds can be provided, based on which one or more operating modes is / are selected. Alternatively or additionally, an operating mode can be selected at intervals from the occurrence of an event, e.g. after detection of a mains voltage failure by the detection circuit E. In this way, different operating modes can be selected at fixed or variable intervals from the event.

[0052] In principle, the LED groups G1, G2, G1', G2' can also emit in different colors. The radiation / light from LED chips in the second LED chip group G2, G2' lies in a different spectrum (for example, the red spectrum), which is not converted by a color conversion substance, in particular a phosphor, in the covering layer T, T', than the radiation emitted by the LED chips in the first group G1, G1'.

[0053] Of course, the LED module M, M' according to the invention can be used and arranged individually or in combination with other LED modules. In this case, the combination of the LED module M, M' according to the invention with an LED module that has the same number of LED chips in the same arrangement, for example in the same grid, is particularly interesting. This is particularly useful when, in a first operating mode, e.g., a normal light mode, several LED modules are to emit the same light output, while in another operating mode, e.g., an emergency light mode, only the LED modules M, M' according to the invention designed for this mode or their LED chips of the second group G2, G2' are to be operated. In this case, the energy requirement can be greatly reduced, particularly in the case of emergency light luminaires N, thereby significantly extending the possible operating time of the emergency light luminaires N in the emergency light mode.In particular, the energy storage C is then subjected to less strain.

[0054] According to the invention, the combination of the LED module M, M' according to the invention with an emergency light N is provided. The emergency light can then, for example, be combined with further LED modules, in particular with an identical number and arrangement of LED chips.

[0055] Preferably, the LED modules M, M' according to the invention are designed such that, compared to other LED modules with multiple LED chips, there is no deviation in the arrangement of the LED chips on the LED module and / or the emitted light output during normal operation.

[0056] It goes without saying that, especially when multiple LED chip groups are present, different conductor routing and connection arrangements may be required. The only important thing is that each LED group can be powered by a separate power supply.

Claims

[1] Luminaire comprising at least one LED module (M, M') comprising: - a carrier, - a first group (G1, G1 ) and a second group (G2, G2') of LED chips arranged on the carrier, and - a uniform layer (T, T') covering all LED chips, which has at least one Contains a color conversion substance that converts the spectrum of the LEDs of a group (G1; G1 ) into a spectrum with a different dominant wavelength, where: - each group (G1, G2; G1', G2') comprises at least one, preferably several LED chips, - the LED chips of a group (G1, G2; G1', G2') are connected in series and can be powered from the same electrical supply, - the LED chips of different groups (G1, G2; G1', G2') independently of each other starting from can be supplied with different electrical supplies, and - the light output of the second group (G2, G2') of LED chips is in a range of 1%-25% of the light output of the LED chips of the first group (G1, G1 ) and / or the number of LED chips of the second group (G2, G2') corresponds to 1%-25% of the number of LED chips of the first group (G1, G1 ), wherein the luminaire has an independent electrical supply for each group of LED chips, wherein at least one group of LED chips is operable from a first electrical supply and at least one group of LED chips is operable from a second electrical supply independent of the first electrical supply, wherein the luminaire is an LED-based emergency luminaire and comprises: - as the second electrical supply an energy storage, - a connection for connecting the luminaire to a first electrical supply and - a detection circuit designed to detect an interruption of the first electrical supply, wherein the luminaire is designed to operate at least the LED chips of one group of the at least one LED module when the first electrical supply is applied and to operate at least the LED chips of another group when an interruption of the first electrical supply is detected by the detection circuit, and wherein the radiation emitted by the LED chips of the second group (G2, G2') is not converted by the at least one color conversion substance in the covering layer (T, T'). [2] Luminaire according to claim 1, wherein the covering layer (T, T') is applied above / on the LED chips, in particular in a "dam-and-fill" or by a dispensing process, e.g. as a spherical head or globe top. [3] Luminaire according to claim 1 or 2, wherein the color conversion substance contains a phosphor. [4] Luminaire according to one of the preceding claims, wherein the radiation emitted by the LED chips of the first and second group (G1, G2; G1', G2') is light in the visible spectrum. [5] Luminaire according to one of the preceding claims, wherein the LED chips of the second group (G2, G2') emit radiation in the red spectrum. [6] Luminaire according to one of the preceding claims, wherein the light output of the second group (G2, G2') of LED chips is in a range of 5%-10% of the light output of the LED chips of the first group (G1, G1 ) and / or wherein the number of LED chips of the second group (G2, G2') corresponds to 5%-15% of the number of LED chips of the first group (G1, G1'). [7] Luminaire according to one of the preceding claims, wherein the LED module (M, M') has at least one first conductor (L1, L1') for connecting the LED chips of the first group (G1, G1) to a terminal (A1, A1') for connecting the first group (G1, G1) to a first electrical supply and at least one second conductor (L2, L2') for connecting the LED chips of the second group (G2, G2') to another terminal (A2, A2') for connecting the second group (G2, G2') to a second electrical supply, wherein the conductors (L1, L2; L1', L2') are arranged on the carrier. [8] Luminaire according to claim 7, wherein the conductors (L1, L2; L1', L2') are arranged at least partially on the side of the carrier on which the LED chips are arranged and / or wherein the conductors (L1, L2; L1', L2') are arranged at least partially on the side of the carrier on which the LED chips are not arranged. [9] Luminaire according to claim 7 or claim 8, wherein the terminals (A1, A2; A1', A2') are arranged on the support so that they are opposite one another and / or are arranged at least partially parallel to one another, and / or wherein the terminals (A1, A2; A1', A2') are provided on one module side or on opposite module sides. [10] Luminaire according to one of claims 7 to 9, wherein the conductors (L1, L2; L1', L2') are at least partially not covered by the covering layer (T, T'). [11] Luminaire according to one of the preceding claims, wherein the carrier is a printed circuit board or an SMD carrier. [12] Luminaire according to one of the preceding claims, wherein the energy storage device is a battery or an accumulator. [13] Luminaire according to one of the preceding claims, wherein the emergency light operates the other group from the energy storage device.

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