Patent Description:
Lighting modules for generating white light with a specific melanopic flux are known in the art. <CIT>, for instance, describes a LED lighting module for generating illumination that produces white light with adequate melanopic flux, reduced blue light hazard flux and color uniformity comprising: one or more LED light sources, the lighting module being configured to emit, during operation of the system, light having a first spectral intensity profile in a wavelength range from <NUM> to <NUM>, wherein the total radiant power in a first wavelength band from <NUM> to <NUM> is greater than <NUM>% of the total radiant power in said first spectral intensity profile and wherein the total radiant power in a second wavelength band from <NUM> to <NUM> is more than half of the total radiant power in the first spectral intensity profile and wherein the light emitted from said LED lighting module is substantially white light.

Document <CIT> discloses a light generating system of the prior art which includes an array of white light emitting elements, an array of blue light emitting elements and an array of Fresnel lenses.

It appears that there is a desire for lighting that is focused on the needs of humans. This may be indicated a "Human Centric Lighting" (HCL). Human centric light may be useful as such lighting may improve well-being of humans, or improve alertness, or adopt the spectral power distribution to the time of the day. For instance, it appears to be possible to enable different atmosphere lighting or Melanopic boost that can be targeted to the user at a specific moment. In this way, e.g. school lighting to stimulate effectiveness of students depending on the activity may be provided. However, also the circadian rhythm in offices or hospitals may also promoted with human centric lighting. Solutions to increase the Melanopic lux (or Melanopic Daylight Efficiency Ration - MDER) appear to require a peak in the cyan light, around about <NUM>. Creating such spectrum may require a different LED solution than standard white LEDs. However, it appears that due to the differences in color of white and cyan, the light mixing of the colors may be difficult. This may imply an additional diffusor. However, with a diffusor light may be lost. Further, for lighting applications such as office light, a low glare may be required for visual comfort. In short, glare may be described as the phenomenon caused by very bright light sources or by strong brightness contrasts in the visual field. The impact of glare may be linked to the surface area, measured in Candela per square meter. But the experience of glare also depends on parameters like luminance contrasts in the visual field, on the viewer's age, the iris color and individual sensitivity to light. Achieving low glare appears to require beam shaping of the emitted light from the LEDs. Normally LEDs emit a Lambertian uniform emission, which may need to be collimated to direct the light more downward. One may e.g. use 3D lenses to collimate the LED light and then a sheet with patterns to mix the light a bit such that the individual LED sources are less visible. The result is that the emitted radiation is mostly downward and a low glare is achieved. The combination of 3D lenses and such patterned sheet may e.g. result in an optical efficiency (LOR) of above about <NUM>%. A downside is that the lens plate is designed dedicated for the type of LEDs and the number of LEDs. Hence changing LED type and doubling LED count for tunable white requires new investments in lenses, or may even be impossible due to the minimal lens dimension. Alternatively, one may use a diffuser and e.g. micro lens optics. This may give a relatively nice uniform and collimated output. An advantage is that the LED count and types can be easily changed without the need to change the optical architecture. However the overall efficiency may be below about <NUM>% and micro lens optics may be relatively expensive.

It surprisingly appears that the melanopic light sensitive area in the human eye is positioned in a specific part of the eye. It is most sensitive for light moving in the vertical plane. As a consequence, for people working and sitting in an office, the vertical illuminance is the metric used to express the melanopic value. However, this light direction is reduced by the requirements to have low glare luminaires. A low glare luminaire directs the light downward and has a low vertical illuminance value. Therefore, it was surprisingly found that for an efficient melanopic light increase, this light should be (primarily) emitted in the vertical direction, whilst the white light should be collimated to illuminate the desks properly with low glare.

Hence, it is an aspect of the invention to provide an alternative light generating device, which preferably further at least partly obviates one or more of above-described drawbacks. The present invention may have as object to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Amongst others, in embodiments the present invention proposes using LED boards with both white and cyan LEDs, and lens plates with lenses only on the white LEDs and not on the cyan LEDs. As a result, the white light is collimated and optimized for glare and horizontal illumination, whilst the cyan light (typically only about <NUM>% of the total) is not collimated and will have a higher vertical illuminance.

In a first aspect, the invention provides a light generating system ("lighting system") comprising a first light source, a second light source, and optics. The first light source is configured to generate first light source light having in a first operational mode a first spectral power distribution. According to the invention, the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>. The second light source is configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution. According to the invention, the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>. Alternatively or additionally, in embodiments, the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>. The optics are configured to beam shape at least the first light source light.

The light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction and a relative intensity of the second light source light to the second system light is higher than the relative intensity of the second light source light to the first system light.

According to the invention, the light generating system comprises a plurality of first light sources, a plurality of second light sources, and optics. The light sources are configured in an array (or in respective arrays), such as an 1D array. The optics may comprise beam shaping elements, which are also configured in an array, such as an 1D array. According to the invention, the first light sources are configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>. The first light sources are configured in a first array having a first pitch (P1). According to the invention, the second light sources are configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM> according to the invention, and in a non-claimed embodiment, in a second wavelength range of one or more of (i) <NUM>-<NUM> and (ii) <NUM>-<NUM>. According to the invention, the second light sources are configured in a second array having a second pitch (P2). The optics comprise a plurality of beam shaping elements configured to beam shape at least the first light source light. According to the invention, the beam shaping elements are configured in a third array having a third pitch (P3), such as an 1D array. The beam shaping elements have a first diameter (D) (which may in embodiments also refer to an equivalent circular diameter). According to the invention, P1=P3. Further, according to the invention, P2≥P1. Yet further, in specific embodiments D/P1≤<NUM>, even more especially <NUM>≤D/P1≤<NUM>, such as especially <NUM>≤D/P1≤<NUM>.

With such light generating system(s), glare conditions can be met, white light may be provided in a vertical direction, e.g. for use on a desk, and in a (more) vertical direction light may be provided that is (relatively more) enriched with cyan light. Hence, the MDER values in different directions may differ. In this way, a more efficient MDER light generating system may be provided. Further, it still may be possible to have the presence of cyan light sources essentially invisible for a user.

Alternatively, in an unclaimed embodiment, when second light source light having a wavelength selected from the <NUM>-<NUM> is applied, such light may be used for disinfection purposes.

According to the invention, a light generating system comprises a first plurality of light sources, a second plurality of light sources, and optics, wherein: (a) the first light sources are configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; wherein the first plurality of light sources are configured in a first array having a first pitch, P1; (b) the second light sources are configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>; wherein the second plurality of light sources are configured in a second array having a second pitch, P2; (c) the optics comprise a plurality of beam shaping elements configured to beam shape at least the first light source light; wherein the beam shaping elements are configured in a third array having a third pitch, P3, and wherein the beam shaping elements have a first diameter D; P1 = P3 and P2 ≥ P1; (d) the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction; (e) the first system light has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range; and (f) the second system light has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range; wherein under a first angle α1 relative to a normal to the light generating system the first ratio R1 is selected from the range of <NUM>-<NUM>, wherein under a second angle α2 relative to a normal to the light generating system the second ratio R2 is selected from the range of <NUM>-<NUM>, wherein the ratio R2/R1 > <NUM>, and wherein the second angle α2 is larger than first angle α1.

Further embodiments not claimed provide a light generating system comprising a plurality of first light sources, a plurality of second light sources, and optics, wherein: (a) the first light sources are configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; wherein the first light sources are configured in a first array having a first pitch (P1); (b) the second light sources are configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of one or more of (i) <NUM>-<NUM> and (ii) <NUM>-<NUM>; wherein the second light sources are configured in a second array having a second pitch (P2); (c) the optics comprise a plurality of beam shaping elements configured to beam shape at least the first light source light; wherein the beam shaping elements are configured in a third array having a third pitch (P3), and wherein the beam shaping elements have a first diameter (D); and (d) P1=P3 and P2≥P1 and <NUM>≤D/P1≤<NUM>.

The first system light in the first direction comprises the first light source light and the second light source light, wherein the first system light has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range. Further, the second system light in the second direction at least comprises the second light source light, wherein the second system light has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range. The ratio R2/R1><NUM>, such as R2/R1≥<NUM> in embodiments. Embodiments not claimed provide a light generating system comprising a first light source, a second light source, and optics, wherein: (a) the first light source is configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; (b) the second light source is configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>; (c) the optics are configured to beam shape at least the first light source light; (d) the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction; (e) the first system light in the first direction comprises the first light source light and the second light source light, wherein the first system light has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range; and (f) the second system light in the second direction at least comprises the second light source light, wherein the second system light has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range, wherein R2/R1><NUM>.

Embodiments not claimed provide for a light generating system comprising a first light source, a second light source, and optics, wherein: (a) the first light source is configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; (b) the second light source is configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>; (c) the optics are configured to beam shape at least the first light source light; (d) the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction; (e) the first system light in the first direction comprises the first light source light and the second light source light; (f) the second system light in the second direction at least comprises the second light source light; and (g) a relative intensity of the second light source light to the second system light is higher than the relative intensity of the second light source light to the first system light. Second light having a wavelength selected from the range of <NUM>-<NUM>, such as selected from the range of about <NUM>-<NUM>, may e.g. be used for disinfection purposes.

Hence, the relative intensities of the first light source light and second light source light may differ in dependence of an angle relative to a normal to the light generating system, such as relative to a normal to a luminaire. Especially, along the normal the ratio of the second light source light to the first light source light (comparing the intensities in power, such as Watts) is smaller than at non-zero angles to such normal, where such ratio may be larger.

In specific embodiments, the second light source light is enriched (relatively more power) in the second wavelength range relative to the first light source light. Or, the first light source light is depleted (relatively less power) in the second wavelength range relative to the second light source light. In specific embodiments (see also below), the second light source light may essentially consist of light having wavelengths in the <NUM>-<NUM> (not claimed) or, according to the invention, in the <NUM>-<NUM> wavelength range. Here below, especially the invention is explained in relation to second light source light that is essentially cyan light (<NUM>-<NUM> light), or that is (white light) enriched with cyan light.

As indicated above, the light generating system comprises a plurality of first light sources, a plurality of second light sources, and optics. These items are further discussed below in general and in more detail, respectively.

The term "light source" may refer to a semiconductor light-emitting device, such as a light emitting diode (LEDs), a resonant cavity light emitting diode (RCLED), a vertical cavity laser diode (VCSELs), an edge emitting laser, etc.. The term "light source" may also refer to an organic light-emitting diode, such as a passive-matrix (PMOLED) or an active-matrix (AMOLED). In a specific embodiment, the light source comprises a solid state light source (such as a LED or laser diode). In an embodiment, the light source comprises a LED (light emitting diode). The term LED may also refer to a plurality of LEDs. Further, the term "light source" may in embodiments also refer to a so-called chips-on-board (COB) light source. The term "COB" especially refers to LED chips in the form of a semiconductor chip that is neither encased nor connected but directly mounted onto a substrate, such as a PCB. Hence, a plurality of semiconductor light sources may be configured on the same substrate. In embodiments, a COB is a multi LED chip configured together as a single lighting module. The term "light source" may also relate to a plurality of (essentially identical (or different)) light sources, such as <NUM>-<NUM> solid state light sources. In embodiments, the light source may comprise one or more micro-optical elements (array of micro lenses) downstream of a single solid state light source, such as a LED, or downstream of a plurality of solid state light sources (i.e. e.g. shared by multiple LEDs). In embodiments, the light source may comprise a LED with on-chip optics. In embodiments, the light source comprises a pixelated single LEDs (with or without optics) (offering in embodiments on-chip beam steering).

The phrases "different light sources" or "a plurality of different light sources", and similar phrases, may in embodiments refer to a plurality of solid state light sources selected from at least two different bins. Likewise, the phrases "identical light sources" or "a plurality of same light sources", and similar phrases, may in embodiments refer to a plurality of solid state light sources selected from the same bin.

The terms "upstream" and "downstream" relate to an arrangement of items or features relative to the propagation of the light from a light generating means (here the especially the light source), wherein relative to a first position within a beam of light from the light generating means, a second position in the beam of light closer to the light generating means is "upstream", and a third position within the beam of light further away from the light generating means is "downstream".

Especially, the first light sources are configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>. Especially, the first light source light is white light.

The term "white light" herein, is known to the person skilled in the art. It especially relates to light having a correlated color temperature (CCT) between about <NUM> and <NUM>, such as between <NUM> and <NUM>, especially <NUM>-<NUM>, for general lighting especially in the range of about <NUM> and <NUM>. In embodiments, for backlighting purposes the correlated color temperature (CCT) may especially be in the range of about <NUM> and <NUM>. Yet further, in embodiments the correlated color temperature (CCT) is especially within about <NUM> SDCM (standard deviation of color matching) from the BBL (black body locus), especially within about <NUM> SDCM from the BBL, even more especially within about <NUM> SDCM from the BBL. The terms "visible", "visible light" or "visible emission" and similar terms refer to light having one or more wavelengths in the range of about <NUM>-<NUM>.

Especially, the first light sources may have a CCT selected from the range of <NUM>-<NUM>, a CRI selected from the range of at least about <NUM>. In embodiments, R9 may be selected from the range of >-<NUM>, such as about at least <NUM>. Hence, in embodiments the first light source light is white light.

Especially, the first light source comprises a solid state light source, more especially a LED. As further elucidated below, the light generating system according to the invention comprises a plurality of first light sources.

When a plurality of first light sources is applied, they may all have essentially the same CCT. However, in other embodiments two or more sets of different first light sources may be applied, differing in CCT, such as differing with at least <NUM>, like differing at least about <NUM>. For instance, in embodiments a first set of first light sources may have a CCT selected from the range of <NUM>-<NUM>, such as about <NUM>, and a second set of first light sources may have a CCT selected from the range of <NUM>-<NUM>, such as about <NUM> or <NUM>. Hence, in embodiments two or more sets of different first light sources may be applied, which may be from different bins. However, the first light sources of the two or more sets may especially be configured to generate white light (as further described herein).

Further, the second light sources are configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>. Especially, the second light source is configured to generate second light source light having a relatively large cyan content. The second light source light may be white light, but will in general be colored light, such as with a strong, or essentially only cyan hue. Hence, in embodiments at least <NUM>% of the total power of the second light source light (in the visible wavelength range) is within the second wavelength range. Hence, a percentage of the power in the <NUM>-<NUM> relative to the total power in the <NUM>-<NUM> of the second light source light may especially be at least <NUM>%, such as even more especially at least <NUM>%. In specific embodiments, the second light source light has a dominant wavelength selected from the range of <NUM>-<NUM>. Hence, in embodiments at least <NUM>% of the total power in the visible (of the second light source light) will be found in the <NUM>-<NUM> wavelength range.

In non-claimed embodiments, the second light may have a peak wavelength selected from the range of <NUM>-<NUM>, even more especially <NUM>-<NUM>, such as selected from the range of <NUM>-<NUM>. Even more especially, the peak wavelength of the second light may in embodiments selected from the range of <NUM>-<NUM>, such as <NUM>-<NUM>. Hence, in embodiments at least <NUM>% of the total power of the second light source light (in the visible wavelength range) is within the second wavelength range. Hence, a percentage of the power in the <NUM>-<NUM> relative to the total power in the <NUM>-<NUM> of the second light source light may especially be at least <NUM>%, such as even more especially at least <NUM>%. In specific embodiments, the second light source light has a dominant wavelength selected from the range of <NUM>-<NUM>. Hence, in embodiments at least <NUM>% of the total power in the visible (of the second light source light) will be found in the <NUM>-<NUM> wavelength range, such as <NUM>-<NUM>.

The term "dominant wavelength" may refer to the wavelength of the monochromatic stimulus that, when additively mixed in suitable proportions with the specified achromatic stimulus, matches the color stimulus considered.

Especially, the second light sources comprise solid state light sources, more especially LEDs. As further elucidated below, the light generating system according to the invention comprises a plurality of second light sources.

The light generating system further comprises optics configured to beam shape at least the first light source light. In embodiments, the optics are configured to reduce glare of at least the first light source light. Hence, in embodiments the optics may be configured to provide a beam of first light source light having full width half maximum at maximum of about <NUM>° from a normal to the first light source (or an exit window of the light generating device). Especially, in embodiments the unified glare rating (UGR) is <NUM> or smaller.

The light generating system is configured to generate system light. As indicated above, and also further elucidated below, there may be an angular dependence of the spectral power distribution, such as relative to a normal to an exit window of the light generating device. The change may be gradual with changing angle. Herein, two types of system light are described, for the sake of understanding, which are indicated with first system light and second system light. In general, the former is the system light along an optical axis of the system light and/or a normal to an exit window of the light generating device and the latter may refer to the system light under specific angles relative to the optical axis of the system light and/or a normal to an exit window of the light generating device.

The phrase "relative to a normal" and similar phrases may e.g. refer to embodiments such as a normal relative to al luminaire. For instance, the light generating system may have an exit window, from which the system light may escape. The normal may be perpendicular to such exit window. This may be an exit window of a luminaire.

In embodiments, the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction. Especially, the spectral power distributions of the first system light and the second system light are different.

In specific embodiments, the light generating system is configured to provide the first light source light and the second light source light, and thus also the first system light and the second system light within a cone having angles to a cone axis (or normal to the exit window of the light generating device) equal to or smaller than <NUM>°. For instance, the light generating system may be used as downlight and may in embodiments not have an uplighting functionality.

The fact that the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction may not exclude that there may also different direction in which the first system light and the second system light are essentially the same. However, there are at least two directions, and in general a plurality of directions wherein the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction, wherein the spectral power distributions differ (such as also indicated with the ratios, see below). Assuming the first system light to have an optical axis, especially under angles relative to this optical axis, the spectral power distribution in one or more other directions may differ from the spectral power distribution of the system light along the optical axis. Especially, the spectral power distribution may differ at larger angles from the normal (see also below).

In embodiments, the first system light in the first direction comprises the first light source light and the second light source light. In such embodiments, the first system light in the second wavelength range may primarily be provided by the second light source light. However, it is not excluded that the second light source light also has intensity in the wavelength range of <NUM>-<NUM> other than the second wavelength range.

The first system light has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range. In embodiments, the first ratio R1 may be selected from the range of <NUM>-<NUM>. Hence, about <NUM>% of the lumens of the first system light may be cyan type of light.

In (further) embodiments, the second system light in the second direction at least comprises the second light source light, which second light source light may essentially be cyan light. However, it is not excluded that the second system light also comprise first light source light. In such embodiments, the second system light in the second wavelength range may essentially be provided by the second light source light. However, as indicated above, it is not excluded that the second light source light also has intensity in the wavelength range of <NUM>-<NUM> other than the second wavelength range. Further, it is also not excluded that the second system light has intensity in the <NUM>-<NUM> wavelength range contributed by the first light source light.

The second system light has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range. In embodiments, the second ratio R2 may be selected from the range of <NUM>-<NUM>, such as selected from the range of <NUM>-<NUM>, like in specific embodiments selected from the range of <NUM>-<NUM>. Hence, at least about <NUM>% of the lumens of the second system light may be cyan type of light.

The ratio R2/R1><NUM>. In other words, in embodiments the cyan contribution in % of the total power of the system light in the second direction is larger than of the system light in the first direction. Especially, in embodiments R2/R1≥<NUM>.

Under a first angle (α1) relative to (a normal N to) the light generating system the first ratio R1 is selected from the range of <NUM>-<NUM>. Under a second angle (α2) relative to (the normal N to) the light generating system the second ratio R2 is selected from the range of <NUM>-<NUM>, preferably from the range <NUM>-<NUM>. The second angle (α2) is larger than first angle (α1). Even more especially, |α1-α2|=<NUM>°±<NUM>°. The value of the difference in angles may in general not mean a binary transition from the first system light at the first angle to the second system light at the second angle, but will in general be a gradual change wherein the R2/R1 is lower at α1, such as at about <NUM>° relative to a normal, and larger at α2, such as at about <NUM>°. Especially, in embodiments, wherein the second light source may especially be configured to generate cyan second light source light, R2/R1 may be selected from the range of <NUM>-<NUM>, especially at |α1-α2|=<NUM>°±<NUM>°. Even more especially, in embodiments R2/R1 may be selected from the range of <NUM>-<NUM>, especially at |α1-α2|=<NUM>°±<NUM>°, such as in embodiments <NUM>-<NUM>.

In specific embodiments, especially wherein the second light source light may essentially be in the <NUM>-<NUM> range, the cyan/white ratio (ratio of the power in the cyan wavelength range of <NUM>-<NUM>) relative to the total intensity of the (second) system light, at angles of about <NUM>° (relative to a normal to the system), may be selected from the range of about <NUM>:<NUM>-<NUM>:<NUM>, such as <NUM>:<NUM>-<NUM>:<NUM>.

As indicated above, the first light source and/or the second light source may especially be solid state light sources. Such light sources may have a light emitting surface, such as a dye, a phosphor, a lens, etc. Hence, the light sources may have light emitting faces. Further, the light sources may have optical axes, which may especially be perpendicular to (part) of such light emitting face, respectively. Especially, even though the first system light and the second system light may have different spatial (power) distributions, such optical axis emanating from the respective light sources may essentially be parallel. Hence, in embodiments the first light source has a first light emitting face and a first optical axis (O1) configured perpendicular to the light emitting face, wherein the second light source has a second light emitting face and a second optical axis (O2) configured perpendicular to the second light emitting face, wherein the first optical axis (O1) and the second optical axis (O2) are configured colinear. As indicated above, especially the first light source is a solid state light source and the second light source is a solid state light source. Especially, the solid state dies may provide light emitting faces.

More especially, the light generating system may comprise an array of first light sources and second light sources. Especially, in such array the plurality of first light sources may essentially be identical. However, they may also differ, as far as they comply with the herein described conditions for the first light source(s). Likewise, in such array the plurality of second light sources may essentially be identical. However, they may also differ, as far as they comply with the herein described conditions for the second light source(s). Hence, in specific embodiments the light generating system may comprise (i) a plurality of first light sources and a plurality of second light sources; (ii) the first light sources and the second light sources are configured in an array, wherein one or more first light sources alternate with one or more second light sources, wherein the plurality of first light sources are configured in a first array and the plurality of second light sources are configured in a second array; and (iii) the optics comprise a plurality of beam shaping elements configured in a third array, wherein the beam shaping elements are configured downstream of the first light sources.

In embodiments, the beam shaping elements are selected from the group consisting of lenses, reflectors and collimators. When the beam shaping elements comprise collimators, especially these collimators comprise light transparent solid bodies. When the beam shaping elements comprise reflectors, these may be hollow reflectors.

Especially, the beam shaping elements may essentially be configured for collimating the first light source light though in embodiments they may also collimate at least part of the second light source light. Hence, in embodiments there may only be beam shaping elements that primarily beam shape the first light source light and no beam shaping elements that primarily beam shape the second light source light (see further also below).

In embodiments, the beam shaping elements may be configured to provide first system light having a full width half maximum at a maximum about <NUM>*<NUM>° (beam angle of at maximum about <NUM>°), such as at maximum about <NUM>*<NUM>° full width half maximum (beam angle of at maximum about <NUM>°). The solid state light sources as such, may have a full width half maximum at a maximum about <NUM>*<NUM>° (beam angle of at maximum about <NUM>°), which may be a Lambertian type distribution. Hence, the beam shaping elements may be used to collimate the first light source light.

Especially, first system light is the light of the system parallel to a normal to the system. Especially, this may be light essentially perpendicular to the solid state light sources (dies) and essentially parallel to optical axes of the beam shaping elements.

Hence, the first light source light may be collimated. In embodiments, the beam shaping elements may be configured to provide the first light source light having a full width half maximum at a maximum about <NUM>*<NUM>° (beam angle of at maximum about <NUM>°), such as at maximum about <NUM>*<NUM>° full width half maximum (beam angle of at maximum about <NUM>°). The second light source light may be subject to a smaller degree of collimation, or may even not be collimated at all. In embodiments, the second light source light may have may even be decollimated. In embodiments, the second light source light downstream of the beam shaping elements may have a full width half maximum of more than <NUM>*<NUM>° (beam angle more than <NUM>°).

In embodiments, the first light sources in the first array have a first pitch (P1), the second light sources in the second array have a second pitch (P2), and the beam shaping elements in the third array have a third pitch (P3). Especially, in embodiments P1≈ P3, more especially P1=P3. Especially, in embodiments P1=P3 and P2≥P1. For instance, in embodiments <NUM>≤P2/P1≤<NUM>, such as P2=2xP1, or P2=3xP1 or P2=4xP1.

Herein, the array(s) may be 1D arrays or 2D arrays.

The beam shaping elements will in general have an essentially circular cross-section, though other cross-sections may also be possible. Hence, the beam shaping elements have a first diameter (D). For beam shaping elements not having an essentially circular cross-section, the equivalent circular diameter (D) may be applied. The equivalent circular diameter (or ECD) of an (irregularly shaped) two-dimensional shape is the diameter of a circle of equivalent area. For instance, the equivalent circular diameter of a square with side a is <NUM>*a*SQRT(<NUM>/π). For a circle, the diameter is the same as the equivalent circular diameter. Would a circle in an xy-plane with a diameter D be distorted to any other shape (in the xy-plane), without changing the area size, than the equivalent circular diameter of that shape would be D. Especially, the term "diameter" (such as in embodiment the equivalent circular diameter) refers to the largest cross-section. Further, this term may also refer to a cross-section essentially perpendicular to the optical axis to the light source (and/or to an optical axis of the beam shaping element.

In embodiments, D/P1≤<NUM>, such as <NUM>≤D/P1≤<NUM>. Especially, in embodiments wherein <NUM>≤D/P1≤<NUM>. Even more especially, <NUM>≤D/P1≤<NUM>. In such embodiments, the beam shaping elements may be configured downstream of the first light sources, with e.g. the optical axes of the beam shaping elements coinciding with the optical axes of the first light sources. In such embodiments, the beam shaping element and the first light sources may provide a first grid, and the second light sources may be configured between the first light sources at a subset of all intermediate positions (or at all intermediate positions). When D/P1 is larger than <NUM>, this may imply that there may be no separate lens for the second light source(s). Hence, downstream of the second light source there may be no lens or downstream of the second light source there may be part of one or more adjacent lenses that are configured to collimate the first light source light of adjacent first light sources.

Further, in embodiments P2≤<NUM>, such as especially P2≤<NUM>. This may also add to the invisibility of the individual second light sources (when switched on). However, in specific embodiments P2><NUM>, such as at least about <NUM>. However, other dimensions may also be possible. Especially, in embodiments P2>P1.

In general, the equivalent circular diameters based on the cross-sections of the (solid state) light sources will in general be smaller than D. In general, they may be at maximum about <NUM>*D. Or, in other words, the equivalent circular diameter of the beam shaping elements may be about at least twice, such as about at least three time, as large as the equivalent circular diameter of the first (solid state) light sources. Even more especially, in embodiments they may be about at least <NUM> times as large as the equivalent circular diameter of the (solid state) light sources, such as at least <NUM> times.

Even though the beam shaping elements may be configured essentially downstream of the first light sources, in embodiments it is not excluded that part of the (respective) beam shaping element is also configured downstream of the second light sources. Hence, in embodiments the beam shaping elements may also be at least partly configured downstream of the second light sources.

More especially, in embodiments the second light sources in the second array and the beam shaping elements (in the third array <NUM>) are configured such that for a plurality of the second light sources in the second array applies that part of its second light source light propagates through a first beam shaping element configured downstream of a first adjacent first light source and part of its second light source light propagates through a second beam shaping element configured downstream of a second adjacent first light source. Herein, the phrase "for a plurality of the second light sources" is applied, as at the edges this may not always be the case. However, this may apply for a majority of the second light sources. Hence, in an embodiment a grid of first light sources and associated beam shaping elements may be provided, wherein a plurality of second light sources is configured between first light sources, thereby forming a second grid.

Therefore, in embodiments for the second light sources within the plurality of second light sources may apply that they are configured between the respective first adjacent first light source and the respective second adjacent first light source. More especially, in embodiments for one or more second light sources may apply that they are configured between the respective first adjacent first light source, the respective second adjacent first light source, an (respective) third adjacent first light source and optionally a (respective) fourth adjacent first light source.

Yet further especially, thus for one or more of the second light sources in the second array may apply that part of its second light source light propagates through a first beam shaping element configured downstream of a first adjacent first light source, part of its second light source light propagates through a second beam shaping element configured downstream of a second adjacent first light source, part of its second light source light propagates through a third beam shaping element configured downstream of a third adjacent first light source, and optionally part of its second light source light propagates through a fourth beam shaping element configured downstream of a fourth adjacent first light source.

The beam shaping elements may be provided as plate ("lens plate") comprising a plurality of lenses. Such plate may include a plurality of lenses, wherein in embodiments each lens may have an equivalent circular diameter of at least about <NUM>, though other dimensions may also be possible. The lens plate may e.g. include at least <NUM>, such as at least <NUM>, like in embodiments at least <NUM>, such as at least <NUM>, lenses. The lens plate, such as a lens strip, may be rigid or flexible. In specific embodiments, each lens may have an equivalent circular diameter of at least about <NUM>, such as selected from the range of about <NUM>-<NUM>, like <NUM>-<NUM>. Such lens plate may include a linear arrangement of lenses. Hence, in embodiments the beam shaping elements may be provided as lens strip. This may especially be the case when the first light sources and second light sources are configured in a 1D array. Such lens plate may in other embodiments also include a 2D array of lenses.

For other embodiments of the beam shaping elements may also apply that each lens may have an equivalent circular diameter of at least about <NUM>. Further, an array of beam shaping elements may e.g. include at least <NUM>, such as at least <NUM>, like in embodiments at least <NUM>, such as at least <NUM>, beam shaping elements, such as lenses, reflectors or collimators.

Hence, in embodiments no micro lens optics (MLO) may be applied, but lens plates with lenses having an equivalent circular diameter of at least about <NUM>. As indicated above, the lenses are especially configured downstream of the first light sources.

Optionally, a diffusor may be configured downstream of the beam shaping elements. Hence, in specific embodiments the beam shaping elements may comprise lenses, wherein the light generating system further comprises a diffusor configured downstream of the beam shaping elements. Such diffusor may comprise a light transmissive layer, such as a plate or foil, including structures that diffuse the light. Such structures may have dimensions smaller than the solid state light sources. Such diffusor may be use to inhibit visibility of the optical elements from external of the light generating system, such as at a distance of <NUM>, while allowing transmission, such as transmission of essentially all light reaching such diffusor.

As indicated above, the second light source light of a specific second light source may propagate through parts of two or more beam shaping elements. Hence, in specific embodiments the lenses comprise lens edges, wherein the second light sources and the lenses are configured such that part of the second light source light propagates through the lens edges. In yet further specific embodiments, the lens edges may have a higher roughness than the lenses have in average. For instance, the lens edge may have an Ra roughness of at least about <NUM>, such as at least about <NUM>. In average, the Ra roughness of the lens may be smaller than about <NUM>, such as smaller than about <NUM>. At least part of the lens, especially a central part, may have an Ra roughness of <NUM> or smaller, such as about <NUM>. In embodiments, roughness may be created using sandblasting, chemical etching, or discharging.

In embodiments, the first light source(s) and the second light source(s) may be controlled. Even more especially, they may be controlled individually. In this way, the spectral power distribution of the system light may be controlled. For instance, in this way the first light sources configured to generate white light and the second light sources configured to generate (essentially) radiation in the wavelength range of <NUM>-<NUM> and/or in the wavelength range of <NUM>-<NUM> may individually be controlled.

As indicated above, in embodiments the light generating system may comprise a first light source, a second light source, and optics, wherein: (a) the first light source is configured to generate first light source light having in a first operational mode a first spectral power distribution, wherein the first light source light has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; (b) the second light source is configured to generate second light source light having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>; (c) the optics are configured to beam shape at least the first light source light; (d) the light generating system is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction; (e) the first system light in the first direction comprises the first light source light and the second light source light; (f) the second system light in the second direction at least comprises the second light source light; and (g) a relative intensity of the second light source light to the second system light is higher than the relative intensity of the second light source light to the first system light.

In embodiments, the first system light may have a first ratio R'<NUM> of spectral power in the second wavelength range relative to the spectral power in the first wavelength range. Further, in embodiments the second system light has a second ratio R'<NUM> of the spectral power in the second wavelength range relative to the spectral power in the first wavelength range, wherein R'<NUM>/R'<NUM>><NUM>, especially wherein R'<NUM>/R'<NUM>≥<NUM>.

Especially, in embodiments under a first angle (α1) relative to (a normal N to) the light generating system the first ratio R'<NUM> may (thus) be selected from the range of <NUM>-<NUM>. Alternatively or additionally, under a second angle (α2) relative to (the normal N to) the light generating system the second ratio R'<NUM> is selected from the range of <NUM>-<NUM>. Even more especially, |α1-α2|=<NUM>°±<NUM>°. The value of the difference in angles may in general not mean a binary transition from the first system light at the first angle to the second system light at the second angle, but will in general be a gradual change wherein the R'<NUM>/R' <NUM> is lower at α1, such as at about <NUM>° relative to a normal, and larger at α2, such as at about <NUM>°. Especially, in embodiments R'<NUM>/R'<NUM> may be selected from the range of <NUM>-<NUM>, especially at |α1-α2|=<NUM>°±<NUM>°. Even more especially, in embodiments R'<NUM>/R'<NUM> may be selected from the range of <NUM>-<NUM>, especially at |α1-α2|=<NUM>°±<NUM>°, such as in embodiments <NUM>-<NUM>.

In embodiments, under a first angle (α1) relative to (a normal N to) the light generating system the first ratio R'<NUM> is selected from the range of <NUM>-<NUM>, wherein under a second angle (α2) relative to (the normal N to) the light generating system the second ratio R'<NUM> is selected from the range of <NUM>-<NUM>. For instance, R'<NUM> may be selected from the range of <NUM>-<NUM> and R'<NUM> may be selected from the range of <NUM>-<NUM>.

The control system may also be configured to receive and execute instructions form a remote control. In embodiments, the control system may be controlled via an App on a device, such as a portable device, like a Smartphone or I-phone, a tablet, etc.. The device is thus not necessarily coupled to the lighting system, but may be (temporarily) functionally coupled to the lighting system.

The system, or apparatus, or device may execute an action in a "mode" or "operation mode" or "mode of operation". Likewise, in a method an action or stage, or step may be executed in a "mode" or "operation mode" or "mode of operation" or "operational mode". The term "mode" may also be indicated as "controlling mode". This does not exclude that the system, or apparatus, or device may also be adapted for providing another controlling mode, or a plurality of other controlling modes. Likewise, this may not exclude that before executing the mode and/or after executing the mode one or more other modes may be executed.

In specific embodiments, the first light sources may be available in one or more LED strings and the second light sources may be available in one or more other LED strings. Hence, in embodiments the light generating system may comprise (a) a first LED string comprising the plurality of first light sources; (b) a second LED string comprising the plurality of second light sources; and (c) a control system configured to control the first LED string and the second LED string (individually).

In yet a further aspect, the invention provides a lamp or a luminaire comprising the light generating system as defined herein. The luminaire may further comprise a housing, optical elements, louvres, etc. etc.. The lamp or luminaire may further comprise a housing enclosing the first light generating device, the second light generating device, and the optional third light generating device. The lamp or luminaire may comprise a light window in the housing or a housing opening, through which the system light may escape from the housing.

The light generating system may be part of or may be applied in e.g. office lighting systems, household application systems, shop lighting systems, home lighting systems, accent lighting systems, spot lighting systems, theater lighting systems, fiber-optics application systems, projection systems, self-lit display systems, pixelated display systems, segmented display systems, warning sign systems, medical lighting application systems, indicator sign systems, decorative lighting systems, portable systems, automotive applications, (outdoor) road lighting systems, urban lighting systems, green house lighting systems, horticulture lighting, digital projection, or LCD backlighting.

Solutions to increase the melanopic lux (or Melanopic Daylight Efficiency Ration - MDER) may e.g. require a peak in the cyan light around <NUM> (<FIG>). Creating such spectrum requires a different LED solution than standard white LEDs.

In the present invention, amongst others for HCL luminaires it is desired replacing the white (solid state) light source with a light source optimized for melanopic boost. In the present invention, this implies in embodiments that cyan LEDs are added. Amongst others, in embodiments the micro lens optics + diffuser based architecture may result in an acceptable uniform color, but the solution with a lens may results in visibility of the cyan LEDs. This may be undesired, as the preference of end users may be to have a smooth color uniform exit window. In general, it appears to be preferred not have visible cyan dots or artefacts.

As indicated above, there may be some disadvantages in applying a 3D lens based solution: by adding cyan light, or making a tunable white/cyan LEDs on a support, more LEDs may be needed on the support. But the dimension of an efficient 3D lens may be linked to the size of the LED package. Typically a 3D lens requires a diameter of <NUM>, or larger, for <NUM> wide packages. That means that placing the packages close together (as in cyan added support), there may essentially be no space for efficient 3D lenses. This problem is indicated in <FIG>. The right hand side shows that adding more LEDs results in a conflict with the minimum size of the lenses.

As described before, there may be a conflict between low glare and high vertical illuminance. The melanopic boost light may especially be measured in vertical illuminance, but adding the cyan LEDs underneath lenses may be done for glare reduction and actually reduces the vertical illuminance of the emitted cyan light.

The invention may include a support with both white and cyan LEDs, and lens plates with lenses only on the white LEDs and (essentially) not on the cyan LEDs. As a result, the white light may essentially be collimated and optimized for glare and horizontal illumination, whilst the cyan light (typically only <NUM>% of the total) may essentially not be collimated and may have higher vertical illuminance.

Several cases were studied. A first study case of adding cyan is "case A", where both white and cyan have the same optical shape to be collimated (the center drawing of <FIG>), all of horizontal illuminance, vertical illuminance and UGR will be the same as original single white LED, see left drawing in <FIG>) because in this case, there is no change on photometry distribution. However, because of the spectral change by adding the cyan LED, the melanopic efficiency ratio is increased, as well as the melanopic vertical illuminance. In this case, with a certain amount of added cyan, the melanopic ratio of both vertical illuminance and horizontal illuminance to a viewer e.g. increase from MDER =<NUM> (white light) to MDER = <NUM> (white+cyan light). This may just be the consequence of the new spectrum with more cyan.

In <FIG>, reference <NUM> refers to a light generating system; reference <NUM> refers to a first light source, especially a solid state light source. Reference <NUM> refers to a second light source, especially a solid state light source. reference <NUM> refers to optics and reference <NUM> refers to beam shaping elements. In <FIG> (on the left), first light sources <NUM> are depicted, with optical element <NUM> comprising beam shaping elements <NUM>, for each light source <NUM>. In <FIG>, on the right a series of two first light sources <NUM> with in between a second light source <NUM> is depicted, with optical element <NUM> comprising beam shaping elements <NUM>, for each of the first light sources <NUM> and the second light source <NUM>. The lower drawing in <FIG> schematically depicts the same embodiment as in the upper left embodiment, but with second light sources <NUM> configured between the first light sources <NUM>. Hence, the pitches of the first light sources and second light sources are essentially the same. Therefore, in the lower drawing of <FIG>, an embodiment of the light generating system <NUM> is schematically depicted, wherein the second light sources <NUM> in a second array and the beam shaping elements <NUM> are configured such that for a plurality of the second light sources <NUM> in the second array may apply that part of its second light source light propagates through a first beam shaping element <NUM> configured downstream of a first adjacent first light source <NUM> and part of its second light source light propagates through a second beam shaping element <NUM> configured downstream of a second adjacent first light source <NUM>. Hence, in this schematically depicted embodiment, the first light sources <NUM> may be configured in a first array having a first pitch P1 and the second light sources <NUM> may be configured in a second array having a second pitch P2. The optics <NUM> may in embodiments comprise a plurality of beam shaping elements <NUM> configured to beam shape at least the first light source light. Especially, the beam shaping elements <NUM> may be configured in a third array having a third pitch P3. The beam shaping elements <NUM> may have a first diameter D. Especially, P1=P3. Further, especially P2≥P1. Yet further, especially <NUM>≤D/P1≤<NUM>.

In the present invention, especially the cyan light does not have the same optical shape as the white light. As indicated in <FIG>, the cyan LEDs are placed in between the white LEDs but without their own lens. In this case, the photometry distribution of cyan will be changed.

For reference purposes, an optical design is chosen which is not necessarily optimized. The intensity in different view angles were evaluated.

In embodiments, though not mandatory, one may use many cyan LEDs. In case the distance between the cyan LEDs is large (large pitch) there may be a visible pixilation of the cyan LEDs. By using small(er) cyan LEDs, with lower light output, more cyan LEDs may be needed. This may be advantageous for placing them in between the lenses. In the melanopic boost spectrum, the cyan light is around <NUM>% of the total lumen. Instead of or in addition to smaller cyan LEDs, also cyan LEDs may be used which are configured at a larger pitch. Further, smaller may especially indicate less power.

Herein, in embodiments the resulting radiation pattern from the lenses may show (equal to or) less than <NUM>% cyan light in the horizontal direction, and more than <NUM>% in the vertical direction.

The inventors modelled the light distribution with different solutions of the cyan emitter placed between the lenses. In "case B", see <FIG>, lower embodiment or <FIG>, the total UGR increases as a result of both cyan and white light being influenced by the opening on top of the cyan LED in between the white LEDs. This opening creates a reflection interfaces, and light rays are reflected (TIR reflection). The total UGR (sum of white and cyan light) may increase from <NUM> to <NUM> (in this non-optimized embodiment). <FIG> shows the result of the light intensity at different viewing angles. For reference, the first row indicates the original white LEDs with original lens plate (case A). A low intensity is found at highest angles. When adding cyan LEDs between the lenses, we find more light at larger angles (see cases B and C). As indicated above, modelling was done using an example lens. Different lens designs may result in different UGR values. Here, non-optimized results are shown. In <FIG>, the full curves indicate the <NUM>-<NUM>° plane, the dashed curves indicate the <NUM>-<NUM>° plane, and the dot-dashed curves indicate a plane in between. W in the upper right corner refers to the polar plots for the white light (embodiment of first light source light) and C the upper right corner refers to the cyan light (embodiment of second light source light). Case C may be closer to application than case B, as in this non-optimized example the cyan content may be relatively large. Referring also to <FIG>, the following data were retrieved:.

In order to understand the contribution from white and cyan, we need to split the ratio of intensity. And in table1, case A, case B and Case C indicates the intensity distribution from different viewing angles, which will all contribute to illuminance in certain position. There is no significant difference of intensity at <NUM>° but a large difference at <NUM>° viewing angle. <FIG> shows the intensity contribution from white and cyan, using the polar plots. A clear difference between the original lens (Case A) and without lens is visible in the polar intensity of the cyan. To indicate the difference of the cyan ratio in Eh and Ev, one view angle was taken to explain the impact. Here, the view angle <NUM>° was taken (and compared with <NUM>°).

The angles <NUM>° and <NUM>° may for instance be chosen because it may show essentially the biggest difference on intensity.

According to the function between intensity and illuminance, the horizontal and vertical illuminance in certain view angles can be calculated when considering the contribution from a single luminaire, see also <FIG>. Herein, a mounting height of <NUM> to work out the illuminance from white and cyan is assumed. Angle α1 refers to system light <NUM> having angle α1 to the normal N. Especially, angle α1 is <NUM> °. Referring to e.g. <FIG> (lower embodiment, <FIG>, <FIG>, <FIG>, the normal N may especially be perpendicular to the plane of drawings (see e.g. also <FIG>)). This system light <NUM> is especially indicated as first system light <NUM>. Angle α2 refers to system light <NUM> having angle α2 to the normal N. The spectral power distribution of the system light <NUM> under angle α2 may especially be different from the spectral power distribution of the first system light <NUM>. This system light <NUM> is especially indicated as second system light <NUM>. In embodiments, |α1-α2|=<NUM>°±<NUM>°.

Values were determined for a view angle of <NUM>° and a view angle of <NUM>°. Further, amongst others the MDER was evaluated (see below tables). As indicated above, the system may further be optimized.

Both tables show that in case B and C the cyan component is strongly reduced at <NUM> degree, and increased at <NUM>° viewing angle. As a consequence, the MDER value at large angle is strongly increased.

In <FIG>, N refers to a normal to the light generating system <NUM>. Reference <NUM> refers to the system light. In different directions, the system light <NUM> may have different spectral power distributions. Reference α1 refers to a first angle with the normal N, under which first system light <NUM> propagates; reference α2 refers to a second angle with the normal N, under which second system light <NUM> propagates.

Especially, the light generating system <NUM> may be configured to provide in a first operational mode white first system light <NUM> in a first direction and second system light <NUM> in a second direction. In embodiments, the first system light <NUM> in the first direction comprises the first light source light and the second light source light <NUM>. Further, in embodiments the first system light <NUM> has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range; and the second system light <NUM> in the second direction at least comprises the second light source light, wherein the second system light <NUM> has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range. Especially, R2/R1><NUM>. In embodiments, under a first angle α1 relative to a normal N to the light generating system <NUM> the first ratio R1 is selected from the range of <NUM>-<NUM>. Further, in embodiments under a second angle α2 relative to the normal N to the light generating system <NUM> the second ratio R2 is selected from the range of <NUM>-<NUM>. Especially, in embodiments |α1-α2|=<NUM>°±<NUM>°. Further, in specific embodiments wherein R2/R1 may be selected from the range of <NUM>-<NUM>.

The large Eh/klm_cyan and Ev/klm_cyan values at <NUM>° for case B and C in the above example relates to one luminaire and with this specific lens example. We can further finetune the ratio of cyan: white at larger angles, for example by a lower overall cyan intensity. Which can be realized with smaller cyan LEDs or less cyan LEDs. Also we can optimize the lens designs further to adjust the polar plots indicated in <FIG>.

In addition, in reality e.g. an (office) room may be equipped with many luminaires. As a consequence the real Ev value in an office may have a lower cyan ratio at different locations in the room than indicated in the table for case B and C, but still a much higher than the value in case A. The real value may depend on the specific room, luminaire type and luminaire configurations.

In <FIG>, the impact of a larger cyan contribution to the MDER value is indicated. As an example, a standard <NUM> white LED spectrum is taken, having an MDER of <NUM>. Upon adding larger fractions of cyan, the MDER value increases. The cyan itself would have an MDER value of about <NUM>. It is expected that increasing the cyan ratio from <NUM>:<NUM> to <NUM>:<NUM> realizes an MDER increase from about <NUM> to about <NUM>. As can be seen in <FIG>, the second light source light, defined by the cyan peak, may have a dominant wavelength within the <NUM>-<NUM> wavelength range. Also the peak wavelength is within this wavelength range.

Referring to <FIG>, the x-axis indicates the wavelength (nm) and the y axis the intensity, in arbitrary units. The references to the curves first indicate the percentage % of the second light relative to the first light, on the basis of lumens. The second value after the semi colons indicates the respective MDER value. Reference S indicates a reference spectrum of white light having a CRI of <NUM> and a CCT of <NUM>, which has an MDER value of <NUM>. This reference spectrum is essentially white light. As indicated above, white light may especially be used as first light source light. In embodiments, such as in this example, the second light source light may essentially be cyan light.

Case B and case C in the above table may not meet a more desirable ratio for MDER requirement. For instance, would one desire an MDER of <NUM>, one may need to fine tune the flux ratio of cyan/white, not <NUM>:<NUM> any longer. See for instance case C and referring to the observation angle of <NUM>°, and we keep the same light distribution.

For instance, the ratio of cyan/white may be changed into <NUM>:<NUM>, see e.g. the table below. Then, an MDER value of <NUM> may be achieved. Hence, a smaller cyan flux may provide the desired MDER at e.g. <NUM>°.

From the above, it can be concluded that the cyan/white ratio (ratio of the power in the cyan wavelength range of <NUM>-<NUM>) relative to the total intensity of the system light, at angles of about <NUM>°, may be selected from the range of about <NUM>:<NUM>-<NUM>:<NUM>, such as <NUM>:<NUM>-<NUM>:<NUM>.

Controlling the relative intensities may be done by controlling the number of second light sources relative to first light sources and/or by controlling the intensity of the second light sources relative to the first light sources. The former can be done when producing the system. The latter may be done during production of the system but may also be executed during operation of the system, such as by choosing the duty cycle and/or the power provided to the first light sources and/or second light sources.

In case C, a large improvement is made if the lens opening above the cyan LED is modified such that the light reflecting on the interface of that opening is Lambertian emitted from the interface surface. This may be realized by modifying the inner surface of the lens opening for the cyan LED, such as by adding textures. For example, this may be obtained by using a roughness treatment. Charmille VDI14 is good for it. In that case, the UGR with the cyan LED is <NUM> versus the original (non-cyan based) support of <NUM>.

In all of the above documented solutions, the cyan LED may be replaced by an LED with a different wavelength/spectrum not being white. For example, LEDs with a peak emission in the range <NUM>-<NUM> are known to have a disinfection effect on bacteria, fungi, molds and spores. Adding LEDs withing this range will add a disinfection or sanitizing function to the luminaire, where surfaces underneath the luminaire will be disinfected. Adding these deep blue wavelength LEDs in between the white LEDs can be advantageous, similar to the cases described above for adding cyan LEDs. These low wavelength LEDs have a very low contribution to the overall white light (e.g. <NUM>% or less), and therefore the radiation pattern does not necessarily need to obey the rules for low UGR. As a result, there is no specific need for these deep blue LEDs to have the same light distribution as for the white LEDs. Therefore, these LEDs do not need to have a lens.

The fact that the radiation distribution for the non-white LEDs has more radiation to the large angles can be useful also for disinfection light. But for the cyan light it has the additional advantage that the Ev_MDER is increased, reaching a higher effectiveness for persons in the room. This advantage may be less necessarily needed for a disinfection spectrum.

An example of a white light spectrum with added <NUM> light is shown in <FIG>. The added deep blue light is typically within the <NUM>-<NUM>% of the total white light, but is not limited to this range. In a specific high intensity disinfection mode, the white light might be switched off and only deep blue light is on. A light source with this solution could be achieved by having alternating white and deep blue LEDs. According to this invention, the lens plate can have lenses on top of the white LEDs, and no specific lens on top of the deep blue LED. This can be a similar lens plate as described in the cases for the cyan light. In <FIG>, the same reference S is applied. The percentages indicate the deep blue light peaking at about <NUM> relative to the white light, both on the basis of lumen.

<FIG> schematically depicts an embodiment of the light generating system <NUM> comprising a first light source <NUM>, a second light source <NUM>, and optics <NUM>.

The first light source <NUM> is configured to generate first light source light <NUM> having in a first operational mode a first spectral power distribution. Especially, the first light source light <NUM> has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>. For instance, the first light source light may be white light.

The second light source <NUM> is configured to generate second light source light <NUM> having in the first operational mode a second spectral power distribution differing from the first spectral power distribution. In embodiments, the second light source light <NUM> has at least intensity at one or more wavelengths in a second wavelength range of one or more of (i) <NUM>-<NUM> and (ii) <NUM>-<NUM>, such as in the range of <NUM>-<NUM> (especially cyan light). Hence, in embodiments the second light source light <NUM> has at least intensity at one or more wavelengths in the second wavelength range of <NUM>-<NUM>.

In embodiments, the first light source light <NUM> is white light, and at least <NUM>% of the total power (in the visible wavelength range) of the second light source light <NUM> is within the second wavelength range, and wherein the second light source light <NUM> has a dominant wavelength selected from the range of <NUM>-<NUM>.

The optics <NUM> are especially configured to beam shape at least the first light source light <NUM>. In embodiments, the optics <NUM> may comprise a plurality of beam shaping elements <NUM>. Especially, the beam shaping elements <NUM> are configured downstream of the first light sources <NUM>. In embodiments, the beam shaping elements <NUM> are selected from the group consisting of lenses, reflectors and collimators. As schematically depicted, the beam shaping elements <NUM> may in embodiments also at least partly be configured downstream of the second light sources <NUM>.

Especially, the light generating system <NUM> is configured to generate system light <NUM>. In one or more operational modes, the system light <NUM> may be white light, optionally enriched with light at one or more wavelengths in a second wavelength range of one or more of (i) <NUM>-<NUM> and (ii) <NUM>-<NUM>, such as in the range of <NUM>-<NUM> (especially cyan light).

Further, referring to <FIG>, the first light source <NUM> may have a first light emitting face <NUM> and a first optical axis O1 configured perpendicular to the light emitting face <NUM>. Yet further, the second light source <NUM> has a second light emitting face <NUM> and a second optical axis O2 configured perpendicular to the second light emitting face <NUM>. Especially, in embodiments the first optical axis O1 and the second optical axis O2 may be configured colinear. Reference D indicates the (equivalent circular) diameter.

Further, especially the first light source <NUM> is a solid state light source and the second light source <NUM> is a solid state light source.

Hence, amongst others <FIG> schematically depicts an embodiment wherein the first light sources <NUM> have first light emitting faces <NUM>, such as LED dies, and first optical axes O1 configured perpendicular to the light emitting faces <NUM>. Further, amongst others <FIG> schematically depicts an embodiment wherein the second light sources <NUM>, here only one schematically depicted, have second light emitting faces <NUM> and second optical axes O2 configured perpendicular to the second light emitting faces <NUM>, such as LED dies, wherein the first optical axes O1 and the second optical axes O2 are configured colinear. Especially, the first light sources <NUM> are solid state light sources and the second light sources <NUM> are solid state light sources.

Referring to <FIG>, the light generating system <NUM> may comprise a plurality of first light sources <NUM> and a plurality of second light sources <NUM>. Further, the first light sources <NUM> and the second light sources <NUM> may be configured in an array <NUM>. Especially, in embodiments one or more first light sources <NUM> alternate with one or more second light sources <NUM>. In embodiments the plurality of first light sources <NUM> are configured in a first array <NUM> and the plurality of second light sources <NUM> are configured in a second array <NUM>. In embodiments, the first light sources <NUM> in the first array <NUM> have a first pitch P1. In embodiments, the second light sources <NUM> in the second array <NUM> have a second pitch P2. In embodiments, the optics <NUM> may comprise a plurality of beam shaping elements <NUM> configured in a third array <NUM>. In embodiments, the beam shaping elements <NUM> in the third array <NUM> have a third pitch P3. In specific embodiments, P1=P3. In embodiments, the beam shaping elements <NUM> have a first (equivalent circular) diameter D. In embodiments, <NUM>≤D/P1≤<NUM>. Further, in embodiments <NUM>≤D/P1≤<NUM>. Especially, P2≤<NUM>. The second light sources <NUM> in the second array <NUM> and the beam shaping elements <NUM> (in the third array <NUM>) may be configured such that for a plurality of the second light sources <NUM> in the second array <NUM> applies that part of its second light source light <NUM> propagates through a first beam shaping element <NUM> configured downstream of a first adjacent first light source <NUM> and part of its second light source light <NUM> propagates through a second beam shaping element <NUM> configured downstream of a second adjacent first light source <NUM>. Further, for the second light sources <NUM> within the plurality of second light sources <NUM> may apply that they are configured between the (respective) first adjacent first light source <NUM> and the (respective) second adjacent first light source <NUM>. <FIG> schematically depicts 2D arrays.

Referring to <FIG>, in embodiments the light generating system <NUM> may further comprise a diffusor <NUM> configured downstream of the beam shaping elements <NUM>. Essentially all light (of the first light source <NUM> and of the second light source) reaching the diffusor may be transmitted through the diffusor, such as over <NUM>%. The diffusor may include scattering structures, such as e.g. in the case of a translucent window. For instance, the diffusor <NUM> may be of polycarbonate. The diffusor may comprise an optical plate or an optical foil. In embodiments the beam shaping elements <NUM> comprise lenses <NUM>. Further, the lenses <NUM> may comprise lens edges <NUM>. Especially, the second light sources <NUM> and the lenses <NUM> may be configured such that part of the second light source light <NUM> propagates through the lens edges <NUM>. In specific embodiments, the lens edges <NUM> may have a higher roughness than the lenses <NUM> have in average.

Referring to <FIG>, the light generating system <NUM> may comprise a first LED string <NUM> comprising the plurality of first light sources <NUM> and a second LED string <NUM> comprising the plurality of second light sources <NUM>. Yet further, the light generating system <NUM> may comprise a control system <NUM> configured to control the first LED string <NUM> and the second LED string <NUM> (individually).

<FIG> schematically depicts an embodiment with a linear array of first light sources <NUM> (and second light sources <NUM>) and beam shaping elements <NUM>. Here, P1=P3. By way of example P2>P1. However, especially P2 may be equal to or less than about <NUM>. In the embodiment of <FIG>, there are no beam shaping elements <NUM> downstream of the second light sources <NUM>.

<FIG> is a variant on the embodiments of <FIG>, lowest embodiment and <FIG>. Here, the second light sources <NUM> in a second array and the beam shaping elements <NUM> are configured such that for a plurality of the second light sources <NUM> in the second array may apply that part of its second light source light propagates through a first beam shaping element <NUM> configured downstream of a first adjacent first light source <NUM> and part of its second light source light propagates through a second beam shaping element <NUM> configured downstream of a second adjacent first light source <NUM>. Hence, in this schematically depicted embodiment, the first light sources <NUM> may be configured in a first array having a first pitch P1 and the second light sources <NUM> may be configured in a second array having a second pitch P2. The optics <NUM> may in embodiments comprise a plurality of beam shaping elements <NUM> configured to beam shape at least the first light source light. Especially, the beam shaping elements <NUM> may be configured in a third array having a third pitch P3. The beam shaping elements <NUM> may have a first diameter D. Especially, P1=P3. Further, especially P2≥P1. Yet further, especially <NUM>≤D/P1≤<NUM>.

Referring to <FIG>, downstream of the second light source there may be no lens or downstream of the second light source there may be part of one or more adjacent lenses that are configured to collimate the first light source light of adjacent first light sources.

<FIG> schematically depicts an embodiment of a luminaire <NUM> comprising the light generating device <NUM> as described above. Reference <NUM> indicates a user interface, such as a graphical user interface, which may be functionally coupled with the control system <NUM> comprised by or functionally coupled to the lighting system <NUM>. <FIG> also schematically depicts an embodiment of lamp <NUM> comprising the light generating device <NUM>.

Amongst others, the invention may be applied for office lighting, school lighting, hospital lighting, airplane lighting, consumer lamps that promote healthy lighting and concentration lighting (for studying, home-office, etc.), lighting having a disinfection function, etc..

Claim 1:
A light generating system (<NUM>) comprising a plurality of first light sources (<NUM>), a plurality of second light sources (<NUM>), and optics (<NUM>), wherein:
- the first light sources (<NUM>) are configured to generate first light source light (<NUM>) having in a first operational mode a first spectral power distribution, wherein the first light source light (<NUM>) has at least intensity at a plurality of wavelengths in a first wavelength range of <NUM>-<NUM>; wherein the first light sources (<NUM>) are configured in a first array (<NUM>) having a first pitch (P1);
- the second light sources (<NUM>) are configured to generate second light source light (<NUM>) having in the first operational mode a second spectral power distribution differing from the first spectral power distribution, wherein the second light source light (<NUM>) has at least intensity at one or more wavelengths in a second wavelength range of <NUM>-<NUM>; wherein the second light sources (<NUM>) are configured in a second array (<NUM>) having a second pitch (P2);
- the optics (<NUM>) comprise a plurality of beam shaping elements (<NUM>) configured to beam shape at least the first light source light (<NUM>); wherein the beam shaping elements (<NUM>) are configured in a third array (<NUM>) having a third pitch (P3), and wherein the beam shaping elements (<NUM>) have a first diameter (D); and
- <MAT>
- wherein the light generating system (<NUM>) is configured to provide in a first operational mode white first system light in a first direction and second system light in a second direction;
- the first system light (<NUM>) has a first ratio R1 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range; and
- the second system light (<NUM>) has a second ratio R2 of luminous flux in the second wavelength range relative to the luminous flux in the first wavelength range;
- wherein under a first angle (α1) relative to a normal N to the light generating system (<NUM>) the first ratio R1 is selected from the range of <NUM>-<NUM>, wherein under a second angle (α2) relative to the normal N to the light generating system (<NUM>) the second ratio R2 is selected from the range of <NUM>-<NUM>, wherein the ratio R2/R1 > <NUM>, and wherein the second angle (α2) is larger than first angle (α1).