FIELD OF THE INVENTION

The present invention relates to a lighting device, in particular to a remote controllable lighting device and to a luminaire comprising such a lighting device. BACKGROUND OF THE INVENTION

Lighting devices exist in many different forms and based on a variety of light sources. The development of new types of light sources for lighting devices has increased the possibilities to achieve lighting devices providing light with predetermined characteristics, such as light color, light diffusion, color temperature, light intensity, color hue, and color value. There exist different approaches to change the characteristics of a lighting device. One approach is to configure the existing components of the lighting device, such as reflectors, light exit windows or light sources. Another approach is to add further light altering components such as coatings or diffusion elements. A further approach, which is becoming more common, is to add electronics to the lighting device for controlling the characteristics of the emitted light. The lighting device may thus comprise a controller for controlling the light characteristics.

The controller may enable a remote control of the lighting device, such that a user may perform the control from a remote controller such as a smart phone. Further, a group of lighting devices, such as a group of spotlights, may be configured simultaneously.

The remote control feature provides many advantages such as that the light characteristics of a lighting device may be configured without the need for physical interaction with the lighting device. Such interaction may be cumbersome if the lighting device is provided in a ceiling or the like, and also if many lighting devices is to be configured. However, the remote controlling may also render the control more difficult by that it is difficult to see the actual change in the light of the lighting device as response to a control input. Lighting devices comprising e.g. LEDs provides a more or less unidirectional light which requires that the user looks directly into the light beam of the provided light when setting the light characteristics. Thus, there is a need for improvement with regards to remotely controllable lighting devices.

SUMMARY OF THE INVENTION

It is an object of the present invention to overcome the above mentioned problems, and to provide an improved lighting device which is remote controllable. A further object is to provide a remote controllable lighting device which may with advantage be fitted into existing holders. Yet another object is to provide a lighting device which is remote controllable in a more user- friendly manner.

According to a first aspect of the invention, this and other objects are achieved by a lighting device comprising a main light source, a remote controllable controller for controlling the light characteristics of the lighting device , a light directing element arranged to direct light from the main light source through a light exit of the lighting device and into a main beam, and an assist light arrangement adapted to provide light in a secondary direction outside of the main beam, whereby the lighting device is arranged to emit assist light for facilitating the remote control of the light characteristics of the lighting device.

By that the controller is arranged as a part of the lighting device, the lighting device needs to be larger than a conventional lighting device. Thus, a portion of the lighting device protrudes from the conventional holder. In the case the controller is arranged separate from the lighting device housing, the lighting device housing is forced to protrude due to lack of space in the holder. In many cases this protruding portion is not appreciated by end users today, who rather prefer lamps to be as imperceptible as possible. The immediate solution to this problem is to arrange the controller and any further components outside of the holder, e.g. behind the ceiling in the case of a ceiling mounted spotlight holder. However, by the present invention, this seemingly disadvantage of the protruding portion is turned into an advantage by that the protruding portion is utilized for emitting assist light for assisting the remote control of the lighting device. In addition, the assist light creates a sparkle forming a decorative element of the lighting device and providing the lighting device with a unique look. By that the controller may be arranged as a part of the lighting device, the construction requires less space and the lighting device including the controller may be manufactured and handled as a single unit thus simplifying both the manufacturing and installation of the lighting device.

An example of a scenario where the assist light is useful is when setting a light scene with multiple lighting devices. It is hard for the operator wirelessly remote controlling the lighting devices, by for example a handheld device such as a smart phone, to see which lighting device is commissioned. It is especially difficult when the operator is viewing some of the lighting devices from large off axis angles or even from the back. It is also hard to see the direct light output of an individual lighting device, thus rendering setting of e.g. color or intensity difficult and more elaborate since the operator need to move around to each lighting device to be controlled, and in fact counteracts the advantage of remote controlling. By the assist light, the remote controlling is facilitated and may even be enabled from a farther distance than what is possible with conventional wirelessly remote controllable lighting devices. Moreover, even if the lighting device is directed such that the main beam is directed away from the operator, he may still see the light output that he is setting.

The assist light arrangement may comprise a light redirecting member arranged to guide a portion of the light provided by the main light source in the secondary direction outside of the main beam. Thus, both the main light and the assist light may be provided by a single main light source or by a group of main light sources.

The light redirecting member may comprise a light guide. The light guide may be arranged in direct connection to a light exit window arranged at a light exit of the lighting device. The light exit window and the light guide may be made in one piece. Thus, the assist light arrangement may be easily manufactured as a single component. The component may be added to a conventional lighting device, by e.g. replacing an existing light exit window, for enabling the assist light feature.

The light redirecting member may be arranged to guide a portion of the light from nearby the light exit of the lighting device. Thus, the light emitted from the main light source has been better mixed than farther upstream of the light path, i.e. nearer the main light source.

The assist light arrangement may comprise an additional light source. The additional light sources may be arranged to emit light from designated areas of the lighting device. Such areas can be the whole lighting device housing, parts of the housing by means of transmissive windows, a front section of the housing that protrudes outside of a luminaire in which the lighting device is arranged or in a recessed ceiling situation, or through the light exit window. The secondary light source may be a single white or colored light emitting diode (LED), or a ring of LEDs arranged around the main light source on the same printed circuit board (PCB). Thus, the additional light source provides a wide range of possible configurations of the assist light in view of e.g. color, direction, and intensity. Moreover, the controller may be arranged to control the additional light source separately. For example, the additional light source may be arranged to emit light during a limited time such as during remote control of the lighting device in question.

According to a second aspect of the invention, the above and other objects are achieved by a luminaire comprising a lighting device according to the first aspect, and a holder in which the lighting device is arranged.

It is noted that the invention relates to all possible combinations of features recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiments of the invention.

Fig. 1 illustrates a conventional spotlight device.

Fig. 2 illustrates a lighting device according to the present invention arranged in a spotlight holder.

Fig. 3a is a perspective view of the lighting device according to one embodiment of the present invention.

Fig. 3b schematically illustrates the lighting device in figure 3a and light travelling therein.

Figs. 4-7 illustrate different embodiments of a lighting device according to the present invention.

DETAILED DESCRIPTION

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

Figure 1 illustrates a conventional spotlight device 1. The spotlight device 1 comprises a lighting device 10 arranged in a holder 11. The lighting device 10 comprises a light source and a light directing element, such as a reflector, for directing light emitted by the light source. The light is directed through a light exit of the lighting device 10.

The light directing element is arranged such that the light is directed into a main beam. The main beam has a beam diameter and a beam angle. The beam angle is the degree of width that the directed light exits the lighting device. The beam angle may be defined as the angle between those points on opposite sides of the beam axis of the light source where the intensity drops to a certain percentage of maximum, e.g. 10 % or 50 % of maximum. The distance between these points at a certain position may be defined as the beam diameter. The light directing element is thus arranged to direct the light into a main beam in order to focus the light to some degree.

The desired beam angle may vary between different applications, i.e. between different types of lighting devices. As an example, the beam angle for a spotlight device is typically below 22 degrees.

A lighting device 20 according to the present invention is illustrated in figure

2. The lighting device 20 is arranged in the same spotlight holder 11 as in figure 1. Besides the components arranged in the conventional lighting device 10 in figure 1, the lighting device 20 also comprises a controller. The controller enables remote control of the lighting device, and in particular of the light characteristics of the lighting device.

The controller may be arranged to alter characteristics of the emitted light from the light source, such as color temperature, hue, brightness, and color saturation. As another example, the controller may be arranged to alter the direction of the main beam or the size of the main beam diameter by moving the reflector or parts thereof. As yet another example, the controller may be arranged to alter the temporal behavior of the aforementioned characteristics. As yet another example, the controller may be arranged to alter the

distribution of the aforementioned characteristics in the main beam.

If the controller is arranged in the holder 11, the controller and any further electronic components require space in the housing of the lighting device 20 or in the holder 11. Therefore, the lighting device 20 needs to be larger than the lighting device 10 in figure 1. Thus, a portion 21 of the lighting device 20 protrudes from the conventional holder 11.

Alternatively, in the case the controller or other components is arranged separate from the lighting device 20, the lighting device 20 is forced to protrude due lack of space in the holder 11. In many cases this protruding portion 21 is not appreciated by end users today, who rather prefer lamps to be as imperceptible as possible. The immediate solution to this problem is to arrange the controller and any further components outside of the holder 11, e.g. behind the ceiling in the case of a ceiling mounted spotlight holder.

However, by the present invention, this seemingly disadvantage of the protruding portion 21 is turned into an advantage by that the protruding portion 21 is utilized for emitting assist light for assisting the remote control of the lighting device. In addition, the assist light creates a sparkle forming a decorative element of the lighting device and providing the lighting device with a unique look. By that the controller may be arranged as a part of the lighting device, the construction requires less space and the lighting device including the controller may be manufactured and handled as a single unit thus simplifying both the manufacturing and installation of the lighting device.

An operator may wirelessly remote control the lighting device by means of for example a handheld device such as a smart phone. Non-limiting examples of feasible wireless communication technologies are Wi-Fi, cellular data services such as GPRS and 3G, and short distance communication technologies such as Bluetooth.

An example of a scenario where the assist light is useful is when setting a light scene with multiple lighting devices. It is hard for the operator controlling the lighting devices to see which lighting device is commissioned. It is especially hard when the operator is viewing some of the lighting devices from large off axis angles or even from the back. It is also difficult to see the direct light output of an individual lighting device, thus rendering setting of e.g. color or intensity difficult. By the present invention, even if the lighting device is directed such that the main beam is directed away from the operator, he may still see the light output that he is setting.

The assist light may be provided by different configurations of the lighting device, as will be exemplified in the following.

The lighting device 20 of figure 2 is illustrated in perspective in figure 3a and schematically in figure 3b. The lighting device 20 comprises a connector part 33 for connecting the lighting device in a luminaire or to a controller 39. The controller 39 is in this embodiment, and in the following embodiments, included in a printed circuit board (PCB) on which the main light source 34 is mounted. The controller 39 may be in the form of a processor comprising means for wireless communication and relevant control means connected to the light source and/or to other component of the lighting device 20. In an alternative embodiment, the controller 39 may be arranged outside the housing of the lighting device 20.

The lighting device 20 further comprises a mounting ring 30. When the lighting device 20 is arranged in a holder, the mounting ring 30 is arranged to limit the insertion of the lighting device 20 such that the protruding portion 21 actually protrudes from the holder as intended.

The protruding portion 21 comprises a light exit window 31 and an assist light arrangement. The assist light arrangement comprises a light directing member in the form of a light guide 32. The light guide 32 and the light exit window 31 are made in one piece by means of e.g. injection moulding. The light guide 32 may be of the same material as the light exit window 31, which in most cases is polycarbonate (PC) or poly(methyl methacrylate) (PMMA).

The light guide 32 is formed by a plurality of arms extending along the protruding portion 21 and towards the mounting ring 30. The light guide 32 may comprise extra fixation features in order to simplify mechanical assembly.

The light exit window 31 may comprise light directing optics forming a part of the light direction element for directing the light from the main light source 34 into the main beam.

The light guide 32 is an element which transports light from a position and directs it through its optical body. The light travels inside the body until it is scattered to exit a surface of the body.

In the embodiment of figure 3a, the light guide 32 is arranged to transport a small percentage of the light from nearby the light exit window and directs it to the sides of the protruding portion 21 of the lighting device 20.

In figure 3b, examples of light paths in the light device 20 according to this embodiment are illustrated. A main light source 34 is arranged in the lighting device 20. The main light source 34 is in this embodiment a light emitting diode (LED). Other light sources are also feasible in alternative embodiments.

A light directing element in the form of a reflector 35 reflects light 36 emitted by the main light source 34 through the light exit window 31. The directed light 36 is directed into a main beam 37. In this embodiment, the light is directed into a narrow main beam, i.e. the beam angle and thus the main beam diameter is small.

A portion of the light emitted by the main light source 34 travels into the arms of the light guide 32. This so called assist light 38 travels inside the light guide and eventually, after a number of total internal reflections inside the body of the light guide 32, exits the light guide. The assist light 38 exits in a secondary direction outside of the main beam 37.

The assist light 38 may enter the light guide 32 directly from the light source 34 or indirectly by reflection or back scattering on the light exit window 31.

Thus, the assist light arrangement enables that a small amount of the total flux of the light from the main light source 34 is emitted into the angular range outside of the main beam 37, from outside of the main beam 37 to up to 90 degrees off the light axis or even up to 180 degrees off the light axis, i.e. backwards.

The assist light may have the same characteristics as directed light 36 of the main beam 37. Alternatively, the light guide 32 may be configured to alter one or more of the light characteristics, such as the color by color filtering. Thus, the assist light may be easier to identify for a user.

Alternative embodiments of the lighting device 20 where the assist light arrangement comprises a light direction member will now be disclosed with reference to figures 4-6.

In figure 4, the light direction member is formed by a diffusing portion 40 arranged in the reflector 35. By the diffusing portion 40, the assist light 38 emitted by the main light source 34 is guided in the secondary direction outside of the main beam. The assist light 38 may travel to the diffusing portion 40 directly from the light source 34 or indirectly from the light source 34 by reflection or back scattering on the light exit window 31.

In figure 5, the light direction member is formed by one or more facets 50 provided in the reflector 35. By the one or more facets 50, the assist light 38 emitted by the main light source 34 is guided in the secondary direction outside of the main beam. The facets 50 may be formed by light apertures or by at least partly transparent portions in the reflector 35.

In figure 6, the light direction member comprises reflecting elements 60. The reflecting elements 60 are arranged downstream in view of the light emitted by the main light source 34 from the light exit of the reflector 35. The reflecting element 60 reflects a portion of the light in the secondary direction outside of the main beam. The reflected light forms the assist light.

As exemplified above, many types of optical features are possible to transport a portion of the light from the main light source 34 in a secondary direction to the sides or back of the lighting device. Such optical features may contain color filtering to alter the color of the assist light, e.g. by using red plastic for the light directing member to provide a red glow even though the light directed into the main beam is white.

Figure 7 illustrates yet another alternative embodiment of the lighting device

20. In this embodiment, the assist light arrangement comprises additional light sources 70. Light emitted by the additional light sources 70 may have the same or different

characteristics as light emitted by the main light source 34. The additional light sources 70 may be arranged to emit light from designated areas of the lighting device 20. Such areas can be the whole lighting device housing, parts of the housing by means of transmissive windows, a front section of the housing that protrudes outside of a luminaire in which the lighting device is arranged or in a recessed ceiling situation, or through the light exit window. The secondary light source 70 may be a single white or colored LED, or a ring of LEDs arranged around the main light source 34 on the same printed circuit board (PCB). As appreciated by the skilled person and as exemplified above, many configurations are possible. Thus, the additional light source provides a wide range of possible configurations of the assist light in view of e.g. color, direction, and intensity. Moreover, the controller may be arranged to control the additional light source separately. For example, the additional light source may be arranged to emit light during a limited time such as during remote control of that specific lighting device.

The present invention may be applied in spot light devices or luminaries that use one or more light directing elements such as reflectors. This kind of optics is mostly seen in LED lighting. Spot light devices are used in the consumer market as well as the professional market.

The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the assist light may be enabled by reflecting a part of the light emitted by the main light source back into the housing of the lighting device. The housing may be partially transparent, by e.g. facets, diffusion elements or standard total internal reflection (TIR) collimator optics, to make the reflected light visible from outside of the lighting device.

Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. 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. 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.