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Title:
LUMINAIRE FOR INDOOR OR OUTDOOR LIGHTING
Document Type and Number:
WIPO Patent Application WO/2019/192966
Kind Code:
A1
Abstract:
A luminaire (100), comprising a housing (102), a power input interface (104), configured to receive electrical supply power, a lighting unit (108), connected to the power input interface and configured to perform an indoor or outdoor lighting application in a state of operation under reception of the electrical supply power, a failure detection unit (110), configured to detect a predefined state of failure of the lighting unit and to provide a failure signal indicative thereof, and a failure indication unit (112), receiving the failure signal and comprising a visual failure indicator configured to assume a visible non- failure state indicative of the lighting unit being in non-failure state and a visible failure indication state in response to receiving the failure signal wherein the visual failure indicator is configured to remain in the failure indication state in absence of reception of the electrical supply power from the power input interface.

Inventors:
WENDT, Matthias (5656 AE Eindhoven, 5656 AE, NL)
Application Number:
EP2019/058200
Publication Date:
October 10, 2019
Filing Date:
April 01, 2019
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
SIGNIFY HOLDING B.V. (High Tech Campus 48, 5656 AE Eindhoven, 5656 AE, NL)
International Classes:
F21S8/06; F21S8/08; F21V23/04; H05B37/03; F21V25/02; F21W131/103; F21Y115/10
Domestic Patent References:
WO1992000579A11992-01-09
WO2017004667A12017-01-12
Foreign References:
US20120194080A12012-08-02
KR101623808B12016-05-24
US20150296586A12015-10-15
KR20160125911A2016-11-01
US7520636B22009-04-21
Attorney, Agent or Firm:
VAN EEUWIJK, Alexander, Henricus, Walterus et al. (High Tech Campus 7, 5656 AE Eindhoven, 5656 AE, NL)
Download PDF:
Claims:
CLAIMS:

1. A luminaire (100) for indoor or outdoor lighting, the luminaire comprising:

- a housing (102);

- a power input interface (104), configured to receive electrical supply power from an external power-supply device (106);

and, arranged in the housing:

- a lighting unit (108), connected to the power input interface and configured to perform an indoor or outdoor lighting application in a state of operation under reception of the electrical supply power;

- a failure detection unit (110), configured to detect at least one predefined state of failure of the lighting unit and to provide a failure signal indicative thereof; and

- a failure indication unit (112), receiving the failure signal and comprising a visual failure indicator, which is arranged for visual inspection from outside the housing and configured to assume:

- a visible non-failure state indicative of the lighting unit being in non-failure state; and - a visible failure indication state in response to receiving the failure signal;

- wherein the visual failure indicator is configured to remain in the failure indication state in absence of reception of the electrical supply power from the power input interface; and

wherein the visual failure indicator comprises an electronic-paper display, and wherein the visible non- failure state and the visible failure indication state correspond to predetermined states of the electronic-paper display.

2. The luminaire of claim 1, wherein the visual failure indicator comprises a bi stable mechanical device having the visible non-failure state as a first stable state and the visible failure indication state as a second stable state different than the first stable state.

3. The luminaire (200) of claim 1, further comprising a secondary power supply unit (216), and wherein

- the failure indication unit (212) is further configured to receive electrical power from the secondary power supply unit for assuming the visible failure indication state; or wherein - the failure detection unit (210) is further configured to receive electrical power from the secondary power supply unit in absence of reception of electrical power supply from the power input interface; or wherein

- both the failure indication unit, for assuming the visible indication state, and the failure detection unit, in absence of reception of electrical power supply from the power input interface, are configured to receive electrical power from the secondary power supply unit.

4. The luminaire (300) of claim 3, further comprising a secondary-power- supply- control unit (218) including a control-signal input and configured to control provision of electrical power from the secondary power supply unit to the failure indication unit in dependence on an external control signal received via the control-signal input.

5. The luminaire of claim 3 or 4, wherein the visual failure indicator comprises a light-emitting unit configured to emit light as the visible failure indication state.

6. The luminaire (400) of claim 1, further comprising at least one application unit (420) connected to the power input interface and configured to perform an application function different than the lighting application, wherein:

- the failure detection unit is further configured to detect at least one predefined state of failure of the application unit and to provide an application- failure signal indicative thereof as a failure-signal to the failure indication unit.

7. The luminaire of claim 6, wherein the failure detection unit is further configured to provide the failure signal to a respective application- failure indication unit associated to the at least one application unit, the application- failure indication unit comprising an application-failure indicator configured to assume an application non- failure state indicative of the application unit being in non-failure state and an application- failure indication state in response to receiving a corresponding application-failure signal, and wherein the application-failure indication unit is configured to remain in the application- failure indication state in absence of reception of the electrical supply power from the power input interface.

8. The luminaire of claim 7, wherein the at least one application- failure indication unit comprises: - a respective bi-stable mechanical device having the application non-failure state as a first stable state and the application- failure indication state as a second stable state different than the first stable state; or

- an electronic-paper display, wherein the application non- failure state and the application- failure indication state correspond to predetermined states of the electronic-paper display.

9. The luminaire of claim 1 or 6, further comprising a communication unit connected to the power input interface and to the failure detection unit and configured to receive the failure signal and to output, in response to receiving the failure signal and in accordance to a predetermined communication protocol, a failure message comprising failure data indicative thereof

10. The luminaire of claim 9, wherein the communication unit configured to output the failure message according to a wireless communication protocol.

11. An indoor lighting device (650) that comprises a luminaire (600) according to claim 1 and is configured for indoor installation and indoor operation.

12. An outdoor lighting device (750) that comprises a luminaire (700) according to claim 1 and is configured for outdoor installation and outdoor operation.

Description:
Luminaire for indoor or outdoor lighting

FIELD OF THE INVENTION

The present invention relates to a luminaire, to an indoor lighting device and to an outdoor lighting device. BACKGROUND OF THE INVENTION

US 7,520,636 B2 describes a luminaire comprising light emitting diodes (LEDs). The luminaire has a housing with an opening at a light output side, a reflector mounted in the housing, and facing the light output side, a louver mounted at the opening of the housing, and LEDs mounted in the louver, such that the emitted LED light exits the luminaire only after reflection against the reflector, thereby providing indirect light output.

SUMMARY OF THE INVENTION

The effort for accessing such a luminaire for service is enormous and may even require to block the space below the luminaire for an extended time. It would therefore be beneficial to provide a luminaire that allows facilitating its repair.

According to a first aspect of the present invention, a luminaire for indoor or outdoor lighting is disclosed. The luminaire comprises a housing, and power input interface configured to receive electrical supply power from an external power-supply device.

Arranged in the housing, the luminaire further comprises a lighting unit connected to the power input interface and configured to perform an indoor or outdoor lighting application in a state of operation under reception of the electrical supply power, a failure detection unit, configured to detect at least one predefined state of failure of the lighting unit and to provide a failure signal indicative thereof and a failure indication unit receiving the failure signal and comprising a visual failure indicator, which is arranged for visual inspection from outside the housing. The visual failure indicator is configured to assume:

- a visible non-failure state indicative of the lighting unit being in non-failure state; and

- a visible failure indication state in response to receiving the failure signal. The visual failure indicator is also configured to remain in the failure indication state in absence of reception of the electrical supply power from the power input interface.

By assuming a visible failure indication state, the visual failure indicator, which is arranged for visual inspection from outside the housing, visibly indicates to a user, a technician or to an external maintenance tool that the lighting unit of the luminaire is in a predetermined state of failure. Since the visual failure indicator is configured to remain in the failure indication state even in the absence of reception of the electrical supply power from the power input interface, information about a presence of the failure signal, or a current non failure state of the luminaire is always available. This information is thus provided independently on whether the luminaire is currently installed and powered or not. This is particularly advantageous for luminaires that are hard to reach when installed, such as for instance luminaires installed in a ceiling, or at a height that is difficult to reach using standard equipment, or in streetlights. A user, technician or an external maintenance tool can therefore assess the state of failure of the luminaire from outside the housing, and then, based on the information gained from visually inspecting the visual failure indicator, develop an optimized service strategy for the corresponding state of failure of the luminaire.

In the following, embodiments of the luminaire of the first aspect of the invention will be described.

In an embodiment of the luminaire of the first aspect, the lighting application of the lighting unit comprises emitting or ceasing to emit light in response to receiving a respective external illumination control signal. In another embodiment, the lighting application in addition includes selecting an illumination intensity. Additionally, or alternatively, in another embodiment of the luminaire, the lighting application includes controlling a radiation spectrum of the emitted light and, thus, a control of the color of the emitted light.

In an embodiment of the first aspect of the invention, the failure detection unit is configured to detect one predefined state of failure of the lighting unit, particularly, the state of failure wherein the lighting unit is not capable of emitting light. In another embodiment of the luminaire of the first aspect, the failure detection unit is configured to detect a plurality of states of failure. For instance, in one variant, the failure detection unit is configured, in addition to detecting the state of light-emission failure described above, to detect that the lighting unit is emitting light at a light intensity value lower or higher light than a predetermined or expected light intensity range, that the lighting unit is emitting light having a spectral content that deviates from a predetermined or expected light spectrum range.

In a particular embodiment of the luminaire of the first aspect, the failure detection unit is configured to provide one and the same failure signal indicative of a detection of any predefined state of failure. In an alternative embodiment, the detection unit is configured to provide different individual failure signals, one for each of the respective predefined states of failure.

In another embodiment of the luminaire of the first aspect, the visual failure indicator comprises a bi-stable mechanical device having the visible non- failure state as a first stable state and the visible failure indication state as a second stable state different than the first stable state. Since the visual failure indication comprises a bi-stable mechanical device, only two states can be signalized.

Particularly, the bi-stable mechanical device for instance comprises a retro- reflective material that is configured to reflect light and is arranged for visual inspection when the visual failure indicator is in the visible failure indication state. In this particular case, the failure indication state can be easily determined by a user or technician by illuminating the visual failure indicator with a beam of light, for example from a torch or other known sources of light, and detecting the light reflected by the retro -reflective material. The failure indicator may alternatively comprise a fluorescent material that, when being illuminated by an ultraviolet light source and while assuming the visible failure indication state, responds to the incoming ultraviolet light by emitting light in a visible spectral range.

In an alternative embodiment of the luminaire of the first aspect, the visual failure indicator comprises an electronic-paper display, such as for instance an electronic-ink display, and the visible non-failure state and the visible failure indication state correspond to predetermined states at least a section of such display. Since the electronic-paper display can assume more than two states, this embodiment is preferably provided in combination with that variant of the failure indication unit which configured to provide a an individual and distinct failure signal for each detected predefined state of failure. The electronic-paper display can be suitably configured to display a visible pattern in dependence of the detected state of failure. For instance, a pattern can include a message readable, for example, by a user or technician, or a QR-code readable, for example, by an external maintenance device. The displayed pattern thus provides information to a user or technician or to a maintenance device regarding the detected state of failure. This way, an optimized service strategy can be determined based thereon. In another embodiment, the failure indicator comprises electrochromic or LCD segments.

Another embodiment of the luminaire of the first aspect further comprises a secondary power supply unit. This secondary power supply unit can be provided with any of the embodiments previously described. In this embodiment, the failure indication unit is further configured to receive electrical power from the secondary power supply unit for assuming the visible failure indication state.

In an alternative embodiment, the failure detection unit is further configured to receive electrical power from the secondary power supply unit in absence of reception of electrical power supply from the power input interface. In yet another embodiment, both the failure indication unit, for assuming the visible indication state, and the failure detection unit, in absence of reception of electrical power supply from the power input interface, are configured to receive electrical power from the secondary power supply unit.

Thus, in different embodiments, the secondary power supply unit supplies power to either the indication unit, or to the failure detection unit or to both the failure detection unit and the failure indication unit.

The secondary power supply unit is in one particular embodiment a battery installed in a battery compartment arranged in the housing of the luminaire. In one variant, the battery compartment is connected to the power input interface via a charging circuit, thus allowing the use of a rechargeable battery. In another embodiment, the secondary power supply unit additionally or alternatively comprises a super capacitor connected to the power input interface. Also, one or more solar cell can be arranged on or in the housing for providing the electrical power of the secondary power supply unit.

In a further embodiment, the luminaire also comprises a secondary-power- supply-control unit that includes a control-signal input. The secondary-power-supply control unit is configured to control a provision of electrical power from the secondary power supply unit to the failure indication unit in dependence on an external control signal received via the control-signal input. The control signal may be, for instance, an infrared (IR) signal or a radio frequency (RF) signal in accordance with a predetermined suitable communication protocol. In an alternative embodiment, the control signal may be a signal delivered by activating a push-button, or by a shaking or a tilting detector.

The reception of the control signal at the control-signal input of the secondary- power-supply control unit is used to control the provision of electrical power to the failure indication unit, so that the visual failure indicator is configured to assume the visible failure indication state in response to receiving the failure signal and in response to the secondary- power-supply control unit receiving the external control signal. This variant is particularly advantageous when the visual failure indicator requires electrical power not only to assume but also to maintain the visible failure indication state.

In an embodiment, the visual failure indicator comprises a light emitting unit that is different from the lighting unit of the luminaire and configured to emit light when assuming the visible failure indication state. The light emitting unit preferably obtains electrical power from the secondary power supply unit. In a particular embodiment, the light emitting unit is configured to assume one of a plurality of visible failure indication states in response to receiving the failure signal. For instance, the light emitting unit may comprise a plurality of individual light sources, preferably low power light sources like light emitting diodes (LED), each of the LEDs associated with a predetermined state of failure. In another embodiment, the intensity or the spectrum of the light emitted by the light emitting unit depends on the detected predefined state of failure.

Another embodiment of the luminaire further comprises at least one application unit. The application unit is connected to the power input interface and configured to perform an application function different than the lighting application. A non- exhaustive list of suitable application units includes light engines with or without cooling aid, LED driver units, fans, fan driver controllers, sensors, communication units, or other application units commonly used and known by the person skilled in the art. In this embodiment, the failure detection unit is further configured to detect at least one predefined state of failure of the application unit and to provide to the failure indication unit an application-failure signal indicative thereof. The application failure signal acts in this embodiment as a failure-signal. The failure detection unit is, in an embodiment, further configured to provide an application-failure signal indicative of a state of failure of the application unit.

In one embodiment with a plurality of application units connected to the failure detection unit, the failure detection is configured to provide, as the failure signal with an indication of the particular unit that is in the respective failure state. This can for instance take the form of an application failure signal that depends on the application unit where a state of failure has been detected, on the state of failure that has been detected or on both.

This embodiment preferably comprises a visual failure indication including an electronic paper display. Alternatively, the embodiment may comprise a light emitting unit and, in this case, a secondary power supply unit. One embodiment that includes the at least one application unit additionally comprises the failure detection unit further configured to provide the failure signal to a respective application-failure indication unit which is associated with the respective application unit. The application- failure indication unit works as the failure indication unit. It thus comprises an application- failure indicator configured to assume an application non failure state indicative of the application unit being in non- failure state. And the application- failure indicator is also configured to assume an application- failure indication state in response to receiving a corresponding application-failure signal. Suitably, the application- failure indication unit is also configured to remain in the application-failure indication state in absence of reception of the electrical supply power from the power input interface. This allows for an easy identification of a faulty application unit. The application-failure indicator is in one embodiment arranged for visual inspection from outside the housing. However, an alternative embodiment does not have the application-failure indicators arranged in a position where it is not visible from outside the housing.

The one or more application-failure indicators of this embodiment may be of any of the types of failure-indicators described herein as suitable for use with the lighting unit. In particular, the at least one application- failure indication unit may thus comprise a bi stable mechanical device having the application non- failure state as a first stable state and the application-failure indication state as a second stable state different than the first stable state or an electronic-paper display, wherein the application non-failure state and the application- failure indication state correspond to predetermined states of the electronic-paper display.

In another embodiment of the luminaire of the first aspect, which may also comprise at least one application unit, the luminaire further comprises a communication unit connected to the power input interface and to the failure detection unit and configured to receive the failure signal and to output, in response to receiving the failure signal and in accordance to a predetermined communication protocol, a failure message comprising failure data indicative thereof.

In one embodiment, the communication unit is configured to output the failure message according to a wireless communication protocol, such as, but not limited to ZigBee, Bluetooth, Wi-Fi, etc. In an alternative embodiment, the communication unit comprises a speaker configured to broadcast a prestored spoken message comprising information or advice pertaining to the detected state of failure. In yet other embodiments, the

communication unit is configured to output the failure message according to the wireless communication protocol and to broadcast the prestored spoken message. The embodiments comprising a communication unit may also be used in combination with a secondary power source unit which is further configured to provide electrical power to the communication unit for outputting the failure message when no power is being received via the power interface unit. Also, in another embodiment, the luminaires may additionally or alternatively comprise one or more application units with a respective associated application-failure indication unit. The communication unit in is this embodiment also configured to receive an application-failure signal and to provide an application failure message indicative of the state of failure of the luminaire.

According to a second aspect of the present invention, an indoor lighting device is described. The indoor lighting device comprises a luminaire according to the first aspect of the present invention or of any of its embodiments and is configured for indoor installation and indoor operation. It shares the advantages of the embodiments of the luminaire of the first aspect.

According to a third aspect of the present invention, an outdoor lighting device is described. The outdoor lighting device comprises a luminaire according to the first aspect of the present invention or of any of its embodiments and is configured for outdoor installation and outdoor operation. It thus shares the advantages of the embodiments of the luminaire of the first aspect.

Preferably, the outdoor lighting device comprises a transparent sealing layer arranged on the housing and configured to cover the lighting unit and the failure indicator. The sealing layer thus acts as a protective layer and is advantageously used for outdoor applications. The outdoor lighting device is particularly suitable for performing an outdoor lighting operation.

It shall be understood that the luminaire of claim 1 , the indoor lighting device of claim 12, and the outdoor lighting device of claim 13, have similar and/or identical preferred embodiments, in particular, as defined in the dependent claims.

It shall be understood that a preferred embodiment of the present invention can also be any combination of the dependent claims or above embodiments with the respective independent claim.

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following drawings: Fig. 1 shows a block diagram representing an embodiment of a luminaire for indoor or outdoor lighting connected to an external power-supply device,

Fig. 2 shows a block diagram representing another embodiment of a luminaire for indoor or outdoor lighting connected to an external power-supply device,

Fig. 3 shows a block diagram representing another embodiment of a luminaire for indoor or outdoor lighting connected to an external power-supply device,

Fig. 4 shows a block diagram representing another embodiment of a luminaire for indoor or outdoor lighting connected to an external power-supply device,

Fig. 5 shows a block diagram representing another embodiment of a luminaire for indoor or outdoor lighting connected to an external power-supply device,

Fig. 6 shows an exemplary indoor lighting device comprising a luminaire for performing an indoor lighting operation, and

Fig. 7 shows an exemplary outdoor lighting device that comprises a luminaire for performing an outdoor lighting operation.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a block diagram representing an embodiment of a luminaire 100 for indoor or outdoor lighting. The luminaire comprises a housing 102. Power supply is received from an external power supply device 106 via a power input interface 104. Some luminaires receive electrical power from a mains electricity system through an electrical grid. Other luminaries receive electrical power via an Ethernet connection according to a predetermined power supply protocol such as Power over Ethernet. Yet other luminaires receive electrical power from a battery, which in some of these luminaires is configured to be inserted and connected within the housing, but which does not form an essential part of the luminaire.

Arranged in the housing, the luminaire 100 also comprises a lighting unit 108 which is connected to the power input interface, and is thus configured to receive electrical power therefrom. The lighting unit is configured to perform an indoor or outdoor lighting application in a state of operation under reception of the electrical supply power. The lighting application of the lighting unit includes emitting and ceasing to emit light for illuminating or ceasing to illuminate an indoor or outdoor space. For other luminaires, the lighting application further includes selecting an illumination intensity of the lighting unit either from a discreet range of available light intensity values or gradually from a vanishing light intensity value to a maximum light intensity value. Yet other luminaries may, alternatively or additionally control a radiation spectrum of the emitted light and thus control a color thereof.

The luminaire also comprises a failure detection unit 110. The failure detection unit is configured to detect at least one predefined state of failure of the lighting unit and to provide a failure signal indicative thereof. A state of failure of the lighting unit comprises in some luminaries the incapability of emitting light when power for emitting light is supplied to the lighting unit. In other cases, the detection unit detects a state of failure when the lighting unit emits light at a lower intensity than a predetermined expected light intensity amount. In yet other luminaries, the detection unit detects an additional or alternative state of failure when the lighting unit emits light with a light spectrum that deviates from a predetermined expected light spectrum range. A particularly simple failure detection unit may therefore comprise a light detector configured to detect if light is being emitted by the lighting unit. More advanced failure detection unit are configured to detect the intensity of the emitted light, its spectrum, or both the intensity and the spectrum. When a state of failure is detected, the light detection unit is configured to output a failure signal. In some luminaires, the failure signal is indicative of an occurrence of a state of failure, independently on which particular state of failure has occurred (e.g. no light, light at a lower intensity as expected, light having a significantly different spectrum as expected). In other luminaires, the failure signal is different for different predefined states of failure.

The failure signal is received by a failure indication unit 112. The failure indication unit comprises a visual failure indicator 114, which is arranged for visual inspection from outside the housing 102. The visual failure indicator is configured to assume a visible non-failure state indicative of the lighting unit being in non- failure state and a visible failure indication state in response to receiving the failure signal. Further, the visual failure indicator 114 is configured to remain in the failure indication state in absence of reception of the electrical supply power from the power input interface 104. Thus, even in the absence of electrical power supply, a visual failure indicator indicating that a state of failure has been detected, will provide information regarding the detection of a state of failure.

In some luminaires, the visual failure indicator comprises a bi-stable mechanical device having the visible non- failure state as a first stable state and the visible failure indication state as a second stable state different than the first stable state.

Advantageously, the bi-stable mechanical device may comprise a retro -reflective material that is configured to reflect light and arranged for visual inspection when the visual failure indicator is in the visible failure indication state. In this particular case, the failure indication state can be easily determined by a user or technician by illuminating the visual failure indicator with a beam of light, for example from a torch or other know sources of light, and detecting the light reflected by the retro-reflective material.

In alternative luminaires, the visual failure indicator comprises an electronic- paper display, particularly an electronic ink display. In this luminaires the visible non- failure state and the visible failure indication state correspond to predetermined states of the electronic-paper display. In some luminaires capable of providing a plurality of failures signals in dependence on the state of failure detected, the electronic paper display is configured to display a different image or pattern in dependence on the received failure signal. Thus, a more detailed information about the detected state of failure is provided in these luminaires. For example, the different patterns can represent a QR-code that can be read by a suitable device and which may contain information regarding the detected state of failure. The visual failure indicator is therefore advantageously configured to enable keeping track of a status of the luminaire, even in cases where the luminaire is not installed in its operative location.

Fig. 2 shows another exemplary embodiment of a luminaire 200 for indoor or outdoor lighting. The current discussion is mainly focused on the technical features distinguishing the luminaire 200 from the luminaire 100 discussed with reference to Fig. 1. Technical features shared by both luminaires are referred to by the same numerals, except for the first digit, which is“1” for the luminaire 100 of Fig. 1 and“2” for the luminaire 200. Luminaire 200 further comprises a secondary power supply unit 216 that is connected to the failure indication unit 212. The failure indication unit 212 is configured to receive electrical power from the secondary power supply unit for assuming the visible failure indication state. In some luminaires, the secondary power supply unit is a battery that can be installed in a battery compartment arranged in the housing 202. In some of these luminaires, the battery compartment can be connected to the power input interface via a charging circuit (not shown) thus allowing the use of a rechargeable battery. In alternative luminaires, the secondary power supply unit is a super capacitor which in some luminaires is connected to the power input interface.

In some luminaires that are in accordance with this invention, the secondary power source unit 216 is additionally or alternatively configured to supply electric power to the failure detection unit 210 in absence of reception of electrical power supply from the power input interface, as indicated by the dashed line linking the secondary power source unit 216 and the failure detection unit 210. Thus, these luminaires are advantageously configured to detect at least one predetermined state of failure even when no power is being received from the power input interface. The failure detection unit can be configured to perform predetermined failure detection routines using the electrical power received from the secondary power supply unit and, when a state of failure has been identified, the failure detection unit can provide the failure signal indicative thereof A user or technician or an external device can inspect the visual failure indicator 214 and thereby control the presence or not of a predetermined state of failure, even in cases where the luminaire is not receiving electrical power from the power input interface, like for instance while the luminaire is being stored or transported prior to installation.

Fig. 3 shows another embodiment of a luminaire 300. The current discussion is mainly focused on the technical features distinguishing the luminaire 300 from the luminaire 200 discussed with reference to Fig. 2. Technical features shared by both luminaires are referred to by the same numerals, except for the first digit, which is“2” for the luminaire 200 of Fig. 2 and“3” for the luminaire 300. The luminaire 300 also comprises a secondary power supply unit further include a secondary-power- supply control unit 318. The secondary-power-supply control unit comprises a control-signal input. The secondary-power- supply control unit is configured to control the provision of electrical power from the secondary power supply unit 316 to the failure indication unit in dependence on an external control signal received via the control-signal input. These luminaires are therefore advantageously configured to reduce the power consumption of the secondary power supply unit. In some of these luminaires, the secondary-power-supply control unit is configured to receive an external control signal from an external maintenance device. The control signal may be, for instance, an infrared (IR) signal or a radio frequency (RF) signal in accordance with a predetermined suitable communication protocol. In an alternative luminaire, the control signal may be a signal delivered by activating a push-button, or by a shaking or a tilting detector.

The reception of the control signal at the control-signal input of the secondary- power-supply control unit is used to control the provision of electrical power to the failure indication unit, so that the visual failure indicator is configured to assume the visible failure indication state in response to receiving the failure signal and in response to the secondary- power-supply control unit receiving the external control signal.

This variant is particularly advantageous when the visual failure indicator requires electrical power not only to assume but also to maintain the visible failure indication state. For example, some in some luminaires in accordance with this invention, the visual failure indicator 314 of the failure indication unit 312 comprises a light-emitting unit that is configured to emit light as the visible failure indication state. In particular, and in order to lower the energy consumption of the failure indication, the light-emitting unit may comprise one or more light-emitting diodes (LED). Different states of failure can be suitably indicated, for instance, by powering a different number of LEDs or by activating a LED emitting light in a particular spectral range, i.e., with a particular color. However, luminaires in accordance with the invention that comprise visual failure indicators having a light-emitting unit do not necessarily need a secondary-power-supply control unit.

Fig. 4 shows another embodiment of a luminaire 400 in accordance with the present invention. The current discussion is mainly focused on the technical features distinguishing the luminaire 400 from the luminaire 100 discussed with reference to Fig. 1. Technical features shared by both luminaires are referred to by the same numerals, except for the first digit, which is“1” for the luminaire 100 of Fig. 1 and“4” for the luminaire 400. The luminaire 400 further comprises an application unit 420 connected to the power input interface and configured to perform an application function different than the lighting application. The failure detection unit 410 is further configured to detect at least one predefined state of failure of the application unit and to provide an application- failure signal indicative thereof to the failure indication unit 412. The application-failure signal is in this case interpreted as a failure signal by the failure indication unit 412.

Some luminaires in accordance to the present invention comprise more than one application unit, each application unit configured to perform a respective application function. Examples of application units are, for instance, light engines with or without cooling aid, LED driver units, fans, fan driver controllers, sensors, communication units, or other application units commonly used and known by the person skilled in the art. In different variants of the luminaire of the present invention, one or more states of failure of one, more than one, or all of the application units can be detected by the failure detection unit. The failure detection unit 410, upon detecting a state of failure of either the lighting unit 408 or the application unit 420, outputs the application- failure signal to the failure indication unit 412 as the failure signal. The application-failure signal, in some luminaires, comprises failure data pertaining to the detected failure or to the application unit in which the failure has been detected or to both. Suitable visual failure indicators, such as an electronic-paper display, or light-emitting units powered by a secondary power supply unit can be

advantageously configured to assume one of a plurality of different visible failure indication states in response to the detected state of failure. Some of these luminaires may further comprise an application- failure indication unit 422 associated to the at least one application unit 420. In luminaires with more than one application unit, every application unit may have a respective application-failure indication unit. The application- failure indication unit 422 comprises an application- failure indicator (not shown) that is configured to assume an application non-failure state indicative of the application unit being in non- failure state and an application-failure indication state in response to receiving the corresponding application- failure signal comprising information pertaining to that application unit. The application-failure indication unit is also configured to remain in the application-failure indication state in absence of reception of the electrical supply power from the power input interface. The application- failure indicator of these luminaires is not necessarily arranged for inspection from outside the housing, as the visual failure indicator 414. A state of failure on any application unit is visibly signalized by the visual failure indicator 414 assuming the visible failure indication state. A user or technician, aware of the state of failure of the luminaire, may then open the housing and determine which application unit is in a state of failure by inspecting the application-failure indicators associated with the application unit. In advanced luminaires, wherein the visual failure indicator assumes one of a plurality of predetermined failure indication state in dependence on the detected state of failure, a more precise diagnosis of a state of the luminaire can be advantageously performed without removing or deinstalling the luminaire.

The application-failure indicator of the application-failure-indication unit associated to the application unit comprises in some of these luminaires a bi-stable mechanical device having the application non- failure state as a first stable state and the application-failure indication state as a second stable state different than the first stable state. In other alternative luminaires, the application- failure indicator comprises an electronic-paper display, wherein the application non-failure state and the application-failure indication state correspond to predetermined states of the electronic-paper display. In some of the luminaires in accordance with the invention that comprise a plurality of application units, more than one of them having an associated application- failure indication unit, each application-failure indication unit can be of the same or of a different kind. For instance, a first application unit may comprise an application-failure indication unit having a bi-stable mechanical device, and a second application unit may comprise an application- failure indication unit having an electronic-paper display.

Some luminaires in accordance with the invention comprise at least an application unit having an associated application-failure indicator and also comprise a secondary power supply unit. The secondary power supply unit is also configured to supply electrical power to the at least one application- failure indication unit for assuming the application-failure indication state in response to receiving a corresponding application- failure signal.

Fig. 5 shows another embodiment of a luminaire 500 for outdoor or indoor lighting. The current discussion is mainly focused on the technical features distinguishing the luminaire 500 from the luminaire 100 discussed with reference to Fig. 1. Technical features shared by both luminaires are referred to by the same numerals, except for the first digit, which is“1” for the luminaire 100 of Fig. 1 and“5” for the luminaire 500. The luminaire 500 comprises a communication unit 524 connected to the power input interface 504 and to the failure detection unit 510. The communication unit is configured to receive the failure signal and to output, in response to receiving the failure signal and in accordance to a predetermined communication protocol, a failure message comprising failure data indicative thereof. In some of these luminaires, the communication unit is configured to output the failure message according to a wireless communication protocol, such as, but not limited to ZigBee,

Bluetooth, Wi-Fi, etc. In alternative luminaires, the communication unit comprises a speaker configured to broadcast a prestored spoken message comprising information or advice pertaining to the detected state of failure.

These luminaires may also be used in combination with a secondary power source unit which is further configured to provide electrical power to the communication unit for outputting the failure message when no power is being received via the power interface unit. Also, some of these luminaires may additionally or alternatively comprise one or more application units with a respective associated application-failure indication unit. The communication unit in is these luminaires also configured to receive an application- failure signal and to provide an application failure message indicative of the state of failure of the luminaire.

Fig. 6 shows an exemplary indoor lighting device 650 comprising a luminaire 600 for performing an indoor lighting operation. The indoor lighting device 650 is connected to a mains electrical power supply via a dedicated electrical connection 601. Fig. 6 shows a housing 608 of the indoor lighting device into which a lighting unit 608 and a visual failure indicator 614 are attached. The visual failure indicator is configured to assume a visible non failure state indicative of the lighting unit being in non- failure state and a visible failure indication state in response to receiving a failure signal from a failure detection unit (not shown). Here again, the visual failure indicator is configured to remain in the failure indication state in absence of reception of the electrical supply power from a power input interface (not shown). The technical features discussed with respect to luminaire 600 do not represent an exhaustive list. In general, the luminaire 600 may be in accordance with any of the embodiments of the present invention. In particular, the luminaire 600 may also comprise a secondary power supply unit. Additionally, or alternatively, the luminaire 600 may also comprise at least one application unit with an associated application- failure indication unit. Further, the luminaire 600 may comprise a communication unit.

Fig. 7 shows an exemplary outdoor lighting device such as a streetlight 750. Streetlights are typically raised sources of light that comprise a pole and a luminaire attached to the pole. The streetlight 750 comprises a luminaire 700 for performing an outdoor lighting operation. The street light 750 is connected to a mains electrical power supply via a dedicated electrical connection (not shown). Fig. 7 shows a housing 708 of the streetlight, into which a lighting unit 708 and a visual failure indicator 714 are attached. The visual failure indicator 714 is also configured to assume a visible non- failure state indicative of the lighting unit being in non- failure state and a visible failure indication state in response to receiving a failure signal from a failure detection unit (not shown). Here again, the visual failure indicator is configured to remain in the failure indication state in absence of reception of the electrical supply power from a power input interface (not shown). The technical features discussed with respect to luminaire 700 do not represent an exhaustive list. In general, the luminaire 700 may be in accordance with any of the embodiments of the present invention. In particular, the luminaire 700 may also comprise a secondary power supply unit. Additionally, or alternatively, the luminaire 700 may also comprise at least one application unit with an associated application-failure indication unit. Further, the luminaire 700 may comprise a communication unit.

In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a” or "an" does not exclude a plurality.

A single step or other units may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Any reference signs in the claims should not be construed as limiting the scope.