Patent Description:
There is an increasing interest - due to health and safety concerns - to protect people in both personal homes and in office environments from the spread of bacteria and viruses, such as influenza or against the outbreak of novel viruses like the recent COVID-<NUM> pandemic. In the consumer domain (single) air purifying devices are used of which some have ionizing generators included that can kill bacteria and viruses when air ion density is at the correct level, thus improving the indoor air quality (IAQ). Alternatively, ultraviolet (UV) light emitted from ultraviolet light sources can also be used for disinfection.

There is a need to improve the performance and/or safety of disinfection lighting based on UV light emission and accordingly this invention proposes a disinfection device combining UV light emission with a specific constructional configuration, allowing an effective disinfection of large areas, such as personal homes and in office environments.

<CIT> and <CIT> both disclose a disinfection lighting device with an auxiliary UV source for ignition of a first UV source.

<CIT> discloses a lighting assembly with a UV protected light source that emits visible light, and <CIT> discloses an ozone generator and a treatment system comprising an ozone generator. Finally, <CIT> (Art. <NUM>(<NUM>) EPC) discloses an ultraviolet irradiation device including an excimer lamp.

According to a first aspect of the invention a disinfection lighting device is proposed , comprising the features of claim <NUM>.

This design provides a compact and effective disinfecting apparatus wherein UV light with different spectral power distributions is mixed and emitted towards the environment for disinfecting purposes. For an improved disinfection performance, both the first light source and second light source not only are simultaneously in operation (meaning "on-status") during an ignition period, which is typically in the order of about a minute, but preferably are simultaneously in the "on-status" after the ignition for at least a major fraction, for example at least during <NUM>%, such as <NUM>% even up to and including <NUM>%, of their individual normal on-status period, typically during more minutes, or hours or even days. In the normal on-status the respective light source is in stable operation and emits its respective light source light.

In particular, the first spectral power distribution comprises first light source light in the UV wavelength range, wherein the first spectral power distribution has a first dominant wavelength, λ1, and the second spectral power distribution has a second dominant wavelength, λ2, wherein , λ2 < λ1. Preferably, the second dominant wavelength, λ2 < <NUM>. More preferably, the second dominant wavelength, λ2, is in a range from <NUM> to <NUM>. This wavelength range is relatively safe and/or provides a high disinfection performance. Furthermore, in a preferred example, the first dominant wavelength, λ1, ranges <NUM> > λ1 > <NUM>. More preferably, the first dominant wavelength, λ1, ranges <NUM> > λ1 > <NUM> (i.e. UV-B light), or the first dominant wavelength, λ1, ranges <NUM> > λ1 > <NUM> (i.e. near UV-C light). UV-B light is most effective to be used for vitamin D lighting (i.e. an optimum between maximum vitamin D production in the skin and providing less impact on the skin). Dominant wavelength in this context means the highest peak in emission at said wavelength in number of photons.

According to a further example according to the invention, the first light source light has a first spectral power distribution; and the first light source light is white light having a correlated color temperature or color temperature (CT) in a range from <NUM> to <NUM> and a color rendering index (CRI) of at least <NUM>. The CRI is preferably > <NUM>, more preferably CRI > <NUM>, most preferably CRI > <NUM>, such as for example CRI = <NUM>.

In a further effective example, the second light source is not a solid state light source such as for example a gas discharge light source. In certain embodiments, the second light source has a disk or plate shape. This allows the disinfection lighting device to be designed with limited constructional dimensions, in particular as to its height or depth dimension, capable to be implemented in all kinds of applications in a personal home or office space environment. In particular, with this embodiment an advantageous constructional geometry of a large UV light exiting surface area is obtained, which configuration thus exhibits an effective disinfecting functionality.

Additionally, the first light source, and optionally the second light source, is arranged in a housing comprising one or more light reflective inner walls. Herewith an improved exiting of UV light is achieved, wherein the concentration of UV light results in a more effective disinfecting functionality. the concentration of emitted UV light is further improved in an example, wherein the housing is formed as a tapered reflector; wherein the tapered reflector has a narrow end face, a wide end face, as well as an edge wall, preferably an (closed) annular edge wall, connecting the narrow end face and the wide end face, wherein the first light source is closer arranged to the narrow end face compared to the wide end face, and the second light source is closer arranged to the wide end face compared to the narrow end face.

In particular, the second light source is arranged at the wide end face.

In a further example having an improved light distribution, the lighting device light comprises collimated first light source light and uncollimated second light source light. More specifically, an example of the disinfection lighting device with improved light distribution has more than <NUM>% of the first light source light in the lighting device light emanating directly from the light exit window face. Directly in this context means that light is emanating from the light exit window face without being reflected at the light reflective surface of the inner wall of the housing.

According to the invention, the disinfection lighting device comprises a light exit window, wherein the light exit face is the light exit window. Also this allow the disinfection lighting device to be designed with limited constructional dimensions, capable to be implemented in all kinds of lighting applications in a personal home or office space environment.

For a proper operation, the disinfection lighting device may comprise a controller for individually controlling the first light source and the second light source, wherein the disinfection lighting device is configured to generate lighting device light having a controllable spectral power distribution. Herewith, the operational conditions of the disinfection lighting device and hence the disinfecting functionality of the device can be readily set.

Furthermore, the invention also pertains to a lamp comprising the disinfection lighting device according to the invention outlined in this application, wherein the lamp further comprises a cap for electrically and mechanically connecting the lamp to a socket, for example a socket of a luminaire. Accordingly, this allows the disinfection lighting device according to the invention to be retrofitted in an existing luminaire.

Hence, the invention also relates to a luminaire comprising a housing and accommodating at least one disinfection device and/or lamp according to the invention in said housing. The luminaire further comprises mains contact means for connecting to a power source and electrical contact means, for example a socket, for connecting to a disinfection device. The luminaire and/or the lamp and/or the disinfection device may comprise a filter, for example arranged at the light exit face and/or at the light exit window. Said filter blocks undesired radiation generated by the first and /or second light source from being emanated by the disinfection device, the lamp and/or the luminaire. For example, if the second light source is an excimer lamp, such as an KrCl excimer lamp, which typically generates far UVC at a dominant wavelength of about <NUM>, some undesired, potentially harmful, emission in the deep UVC wavelength range of <NUM>-<NUM> is also generated, and said undesired emission is then blocked, either by reflection and/or absorption, by the filter. Thus, a disinfection device, lamp and/or luminaire is provided which is safer to humans.

The invention will now be discussed with reference to the drawings, which show in:.

For a proper understanding of the invention, in the detailed description below corresponding elements or parts of the invention will be denoted with identical reference numerals in the drawings.

<FIG> shows a first example of a not claimed disinfection lighting device according to the disclosure, denoted with reference numeral <NUM>. In a preferred embodiment the disinfection lighting device <NUM> comprises a first light source <NUM> (14a-14b) and a second light source <NUM>.

Specifically, the first light source <NUM> (14a-14b) is composed of a solid-state light source consisting of one or more light emitting diodes, lasers and/or superluminescent diodes (14a-14b). When powered, the first light source <NUM> generates first light source light having a first spectral power distribution. In the Figures the first light source light is denoted with reference numeral <NUM>. For the sake of clarity, the first light source light <NUM> is depicted as single lines illustrating a light beam, however it should be understood that the first light source <NUM> emits broad, spatial distributed first light source light <NUM>.

It should be noted, that the first spectral power distribution as emitted by the first light source <NUM> (14a-14b) comprises the first light source light <NUM> in the UV wavelength range and/or visible wavelength range.

Additionally, the disinfection lighting device <NUM> comprises a second light source <NUM>. The second light source <NUM> generates and emits second light source light, which is denoted with <NUM>. For the sake of clarity, although the second light source light <NUM> is depicted as single lines illustrating a light beam, also here it should be understood that the second light source <NUM> emits broad, spatial distributed second light source light <NUM> having a second spectral power distribution.

The second spectral power distribution of the second light source light <NUM> is different from the first spectral power distribution of the first light source light <NUM>.

Similarly, the second spectral power distribution as emitted by the second light source <NUM> comprises the second light source light <NUM> in the UV wavelength range.

Preferably, the disinfection lighting device <NUM> comprises a housing <NUM> in which the first and second light sources <NUM> and <NUM> are accommodated within the inner chamber <NUM> of the housing <NUM>.

As shown in the Figures, the second light source <NUM> is arranged or disposed at a distance D from the first light source <NUM> (14a-14b), with the distance D being defined as the shortest distance between both light sources <NUM>-<NUM>. In particular, the second light source <NUM> comprises a light input face 13a that is configured in a light receiving relationship with the first light source <NUM> (14a-14b). Similarly, the second light source <NUM> comprises a light exit face 13b, making the second light source <NUM> transmissive for at least (a major) part of the first light source light <NUM>.

In <FIG>, the second light source <NUM> is arranged or disposed at a larger distance D from the first light source <NUM> (14a-14b) compared to the smaller distance D as in the not claimed embodiment of <FIG>, this due to the smaller height/depth dimension of the <FIG> embodiment.

In particular, the (shortest) distance D between the second light source <NUM> and the first light source <NUM> is preferably <NUM> > D > <NUM>, more preferably <NUM> > D > <NUM>, and most preferably <NUM> > D > <NUM>, where L is the length dimension of the disinfection lighting device <NUM>, e.g. measured along the longitudinal axis of the disinfection lighting device <NUM>. See the Figures.

In term of absolute values, it is preferred that <NUM> > D > <NUM>, more preferably <NUM> > D > <NUM>, and most preferably <NUM> > D > <NUM>.

Accordingly, the disinfection lighting device <NUM> is structured to generate a mix of lighting device light comprising the second light source light <NUM> and the first light source light <NUM>. As the second light source <NUM> is transmissive for at least (a major) part of the first light source light <NUM>, a mix of lighting device light composed of second light source light <NUM> and first light source light <NUM> emanates from the light exit face 13b of the second light source <NUM> and is allowed to exit the disinfection lighting device <NUM> via a light exit window <NUM> provided in the housing <NUM> (<FIG> and <FIG>).

In the not claimed examples of <FIG> and <FIG> the first light source light <NUM> generated and emitted by the first light source <NUM> (14a-14b) can exit the light exit window <NUM> either directly or via the light transmissive second light source <NUM>. In either situation both second light source light <NUM> and first light source light <NUM> exit the disinfection lighting device <NUM> as a mix of lighting device light.

This design provides a compact and effective disinfection lighting device wherein UV light with different spectral power distributions (composed of second light source light <NUM> and first light source light <NUM>) is mixed and emitted towards the environment for disinfecting purposes.

For creating improved light distributions, the lighting device light comprises collimated first light source light <NUM> and uncollimated second light source light <NUM>. More specifically, the design of the disinfection lighting device <NUM> is such, that the mix of the lighting device light emanating from the light exit window face 12a is composed of more than <NUM>% of the first light source light <NUM>.

In embodiments, the first light source light <NUM> has a first spatial light distribution having a full width at half maximum (FWHM) < <NUM>°, preferably a FWHM < <NUM>°, more preferably a FWHM < <NUM>°, most preferably a FWHM < <NUM>°.

In embodiments, the second light source light <NUM> has a second spatial light distribution having a FWHM > <NUM>°, preferably a FWHM > <NUM>°, more preferably a FWHM > <NUM>°, most preferably a FWHM > <NUM>°.

A preferred specification of both first and second light sources <NUM>-<NUM> pertain to a first spectral power distribution comprising first light source light <NUM> with the first spectral power distribution having a first dominant wavelength λ1, and a second spectral power distribution comprising second light source light <NUM> having a second dominant wavelength λ2.

Preferably, λ2 < λ1. In a preferred example, the second dominant wavelength λ2 < <NUM>. Furthermore, in another preferred example, the first dominant wavelength λ1 ranges <NUM> > λ1 > <NUM>.

In further detailed specifications of a disinfection lighting device according to an example, the first spectral power distribution comprises first light source light <NUM> in the visible wavelength range. Preferably, the first light source light <NUM> is white light having a correlated color temperature or color temperature in a range from <NUM> to <NUM> and a color rendering index (CRI) of at least <NUM>.

As to a CRI of at least <NUM>, it is noted that such CRI can be obtained by implementing white LEDs and/or a combination of colored LEDs. For example, a phosphor converted white LED may be used i.e. a blue and/or UV LED with a phosphor for at least partly converting LED light into converted light. The LED light and/or the converted light may be the white light. The CRI is preferably > <NUM>, more preferably CRI > <NUM>, most preferably CRI > <NUM>, such as for example a CRI of <NUM>.

The second light source <NUM> may be configured as a gas discharge light source and in particular the second light source <NUM> has a disk or plate shape. The examples of a disk or plate shaped second light source <NUM> are depicted in the embodiments of <FIG>. Such disk or plate shaped configurations provide designs of a disinfection lighting device <NUM> with limited constructional dimensions. Accordingly, such designs allows the disinfection lighting device <NUM> to be implemented in all kinds of applications in a personal home or office space environment. In particular, with a disk or plate shaped embodiment of the second light source <NUM> an advantageous constructional geometry of a large UV light exiting surface area can be obtained, which configuration thus exhibits an effective disinfecting functionality.

The second light source <NUM> may also be a light guide and a UV solid state light emitting UV light. The UV light is coupled into the light guide at a light in-coupling portion/means. The UV light is coupled out by a light outcoupling portion/means e.g. a pattern of reflective dots arranged on a major surface of the light guide preferably the face which is facing the first light source.

The housing <NUM> may comprise one or more light reflective inner walls 11a, further improving the propagation and transmission of both first light source light <NUM> and second light source light <NUM> within the inner chamber <NUM> and reducing absorption within the disinfection lighting device <NUM>. In addition, an improved exiting of the mix of first light source light <NUM> and second light source light <NUM> as lighting device light emanating the light exit window face 12a is achieved.

The concentration of lighting device light emanating the disinfection lighting device <NUM> is further improved in the example of <FIG>. In <FIG>, the housing <NUM> is formed as a tapered reflector. The tapered reflector has a narrow end face denoted with reference numeral <NUM>-<NUM> and a wide end face <NUM>-<NUM>. The narrow end face <NUM>-<NUM> and the wide end face <NUM>-<NUM> are connected by means of edge walls <NUM>-<NUM>. In this example, the edge walls <NUM>-<NUM> is formed as one circumferential edge wall <NUM>-<NUM>.

The reflector is preferably specular reflective in order to collimate the first light source light <NUM> beneficially. The reflector has e.g. a conical and/or a parabolic shape.

The narrow end face <NUM>-<NUM> and the wide end face <NUM>-<NUM> have both a longitudinal dimension or a diameter dimension, denoted as DIMnarrow versus DIMwide. Preferably, the longitudinal / diameter dimension of the wide end face <NUM>-<NUM> is at least twice or more than the longitudinal / diameter dimension of the narrow end face <NUM>-<NUM>, in other words DIMwide > 2DIMnarrow.

As shown in <FIG>, the first light source <NUM> is mounted closer to the narrow end face <NUM>-<NUM> compared to the wide end face <NUM>-<NUM>. The second light source <NUM> is mounted at a position within the housing <NUM> closer to the wide end face <NUM>-<NUM> compared to the narrow end face <NUM>-<NUM>. Preferably, as shown in <FIG>, the second light source <NUM> is arranged at the wide end face <NUM>-<NUM>.

In all embodiments of <FIG>, the disinfection lighting device <NUM> comprises a light exit window <NUM> for exiting the mix of lighting device light composed of first light source light <NUM> and second light source light <NUM>.

In specific claimed embodiments, as shown in <FIG> and <FIG>, the light exit face 13b of the second light source <NUM> constitutes the light exit window <NUM>. These examples result in the disinfection lighting devices with limited constructional dimensions, at least in the height/depth dimensions and as such, these designs allow a beneficial implementation in all kinds of lighting applications in a personal home or office space environment.

The embodiment of <FIG> discloses also a lamp <NUM>, which is provided with a disinfection lighting device <NUM> according to the invention.

Claim 1:
A disinfection lighting device (<NUM>) comprising:
- a first light source (<NUM>), wherein the first light source (<NUM>) comprises a solid-state light source, wherein the solid-state light source comprises one or more light emitting diodes (14a, 14b), lasers and/or superluminescent diodes; wherein the first light source (<NUM>) is configured to generate first light source light (<NUM>) having a first spectral power distribution, wherein the first spectral power distribution comprises first light source light (<NUM>) in the UV wavelength range and/or visible wavelength range;
- a second light source (<NUM>), wherein the second light source (<NUM>) is configured to generate second light source light (<NUM>) having a second spectral power distribution different from the first spectral power distribution, wherein the second spectral power distribution comprises second light source light (<NUM>) in the UV wavelength range,
- wherein the second light source (<NUM>) is arranged at a distance D from the first light source (<NUM>), the second light source (<NUM>) comprises a light input face (13a) configured in a light receiving relationship with the first light source (<NUM>), and the second light source (<NUM>) comprises a light exit face (13b),
- wherein the second light source (<NUM>) is transmissive for at least a major part of the first light source light (<NUM>); and
- wherein the disinfection lighting device (<NUM>) is configured to generate lighting device light (<NUM>, <NUM>) emanating from the light exit face (13b) and comprising the second light source light (<NUM>) and the first light source light (<NUM>),
and characterised in that,
the disinfection lighting device (<NUM>) comprises a light exit window (<NUM>), wherein the light exit face (13b) is the light exit window (<NUM>).