A controller for controlling a linear light source array

Abstract

The invention provides a controller (1) for controlling a linear light source array (20) comprising a plurality of LED light sources (210-220) arranged along a length L of the linear light source. The plurality of LED light sources is configured to provide an array light having a total color temperature CTTOT and a total luminous flux ΦTOT. The controller (1) is configured to provide a first gradient in correlated color temperature on at least a first subset of the plurality of LED light sources arranged along a portion P of the length L having a proximate end (23) and a distal end (24). The first gradient ranges from a proximate LED light source (231) of the subset to a distal LED light source (241). The proximate LED light source is located at the proximate end having a primary proximate correlated color temperature CCTP1, and the distal LED light source (241) is located at the distal end having a primary distant correlated color temperature CCTD1, wherein CCTP1 ≥ CCTD1 + 500K. The first gradient has a first total correlated color temperature CTTOT1 and a first total luminous flux ΦTOT1. A transition to a second gradient in correlated color temperature is provided on the subset of the plurality of LED light sources. The second gradient ranges from the proximate LED light source (231) of the subset to the distal LED light source (241). The second proximate LED light source has a secondary proximate correlated color temperature CCTP2, and the distal LED light source has a secondary distal correlated color temperature CCTD2, wherein CCTP2 ≥ CCTD2 + 500K. The second gradient has a second total correlated color temperature CTTOT2 and a second total luminous flux ΦTOT2. And wherein (i) CCTP2 ≤ CCTP1 - 500K and / or CCTD2 ≤ CCTD1 - 500K, and CTTOT2 ≤ CTTOT1 - 500K, and ΦTOT2 ≤ 0.8ΦTOT1, or (ii) CCTP2 ≥ CCTP1 + 500K and / or CCTD2 ≥ CCTD1 + 500K, and CTTOT2 ≥ CTTOT1 + 500K and ΦTOT2 ≥ 1.2ΦTOT1.

Description

[0001] A CONTROLLER FOR CONTROLLING A LINEAR LIGHT SOURCE ARRAY

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a controller for controlling a linear light source array and to a lighting system comprising such a controller.

[0004] BACKGROUND OF THE INVENTION

[0005] A gradient light device is based on a linear light source array, wherein the light from the linear light source array may shine in a direction and create a surround lighting as an accompaniment for a multimedia device. When a gradient light device is turned on, the light offers a choice of ambient lighting, such as a white light or a gradient of colorful light that, may reacts to the content on multimedia device.

[0006] US 8928249 B2 discloses a system providing white light having a selectable spectral characteristic (e.g. a selectable color temperature, delta UV, and intensity) using a combination of sources (e.g. LEDs) emitting light of three, four, five, or six different characteristics, for example, one or more white LEDs, and one or more LEDs of each of three primary colors, plus cyan and royal blue. A controller maintains a desired spectral characteristic, e.g. for white light at a selected point on or within a desired range of the black body curve. In addition, the controller provides selectable adjustments for values of the spectral characteristics, while maintaining substantially constant overall output intensity for the light output of White LEDs, thereby achieving Maximum Utilization.

[0007] However, there is still a desire to provide an improvement in the decorative lighting effect and light quality when using linear light source array or a luminaire comprising linear light source array.

[0008] SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide an improvement in the decorative lighting effect and light quality when using a linear light source array or a luminaire comprising linear light source array.

[0010] The object of the present invention is furthermore to improve the lighting effect during dimming of a linear light source array. These and other objects are achieved by providing a controller for controlling a linear light source array wherein the linear light source array comprises a plurality of LED light sources arranged along a length L of the linear light source array, the plurality of LED light sources being configured to, in operation and in combination, provide an array light having a total color temperature CTTOT and a total luminous flux TOT. The controller is configured to individually control the plurality of LED light sources to provide a first gradient in correlated color temperature on at least a subset of the plurality of LED light sources arranged along a portion P of the length L, the portion P having a proximate end and a distal end opposite the proximate end, the first gradient ranging from a proximate LED light source of the subset to a distal LED light source of the subset. The proximate LED light source is located at the proximate end having a primary proximate correlated color temperature (CCTP1). The distal LED light source is located at the distal end having a primary distant correlated color temperature (CCTD1). CCTP1 may be at least 300K, such as at least 500K, preferably at least lOOOK, most preferably at least 2000K higher than CCTD1. The first gradient has a first total correlated color temperature CTTOTI and a first total luminous flux OTOTI. The controller is further configured to transition to a second gradient in correlated color temperature provided on the subset of the plurality of LED light sources the second gradient ranging from the proximate LED light source of the subset to the distal LED light source of the subset. The proximate LED light source has a secondary proximate correlated color temperature (CCTP2 ). The distal LED light source has a secondary distal correlated color temperature (CCTD2). CCTP2 may be at least 300K, such as at least 500K, preferably at least lOOOK, most preferably at least 2000K higher than CCTD2. The second gradient has a second total correlated color temperature CTTOT2 and a second total luminous flux OTOT?.

[0011] The controller is further configured to individually control the plurality of LED light sources according to:

[0012] (i) CCTP2 < CCTP1 - 500K and / or CCTD2 < CCTD1 - 500K, and CTTOT2 < CTTOTI - 500K, and OTOT2 < 0.8 OTOT1; or

[0013] (ii) CCTP2 > CCTP1 + 500K and / or CCTD2 > CCTD1 + 500K, and CTTOT2 > CTTOTI + 500K, and OTOT2 > 1.2 OTOT1.

[0014] The present invention provides an improvement in the decorative (gradient) lighting effect and light quality when using a linear light source array or a luminaire comprising a linear light source array. The controller can individually control LED light sources of the linear light source to dim up or to dim down while rendering a gradient light effect in color temperature along at least a portion of the length. During dimming down, the color temperature of at least one of the proximate end or the distal end is decreased while simultaneously decreasing the total color temperature and total luminous flux. During dimming up, the color temperature of at least one of the proximate end or the distal end is increased while simultaneously increasing the total color temperature and the total luminous flux. To a user of the lighting system this provides an improved and more sophisticated dimmable gradient light effect.

[0015] The array light provided by the plurality of LED light sources (i.e. the total color temperature CTTOT and the total luminous flux TOT) may be measured at a predefined distance of at least 1 m, such as 1.5 m, alternative at least 2 m or 2,5 m, from the linear light source array. The total color temperature CTTOT and the total luminous flux TOT may thus be measured in the far field of the luminaire.

[0016] During dimming down, the total luminous flux may be decreased by at least 10%, such as at least 20%, especially at least 30% while the total color temperature CTTOT may be decreased by at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K. CCTP2 may be at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K lower than CCTP1 and / or CCTD2 may be at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K lower than CCTD1.

[0017] During dimming up, the total luminous flux may be increased by at least 10%, such as at least 20%, especially at least 30% while the total color temperature CTTOT may be increased by at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K. CCTP2 may be at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K higher than CCTP1 and / or CCTD2 may be at least 300K, such as at least 500K, especially at least lOOOK, more especially at least 2000K higher than CCTD1.

[0018] The controller is configured to vary the luminous flux from at least one LED light source of the plurality of LED light sources, such that during use the controller is capable of increasing or decreasing said total luminous flux.

[0019] The controller may be configured to vary the luminous flux from each of the plurality of LED light sources when controlling the plurality of LED light sources. During use the controller is capable of increasing or decreasing a total luminous flux from the plurality of LED light sources. During dimming up, when the total color temperature of the array light is increased, the controller controls the linear light source array such that the total luminous flux emitting from the LED light sources also is increased. During dimming down, when the total color temperature of the array light is decreased, the controller controls the linear light source array such that the total luminous flux emitting from the LED light sources also is decreased. The total luminous flux emitting from the LED light sources may thus be dependent on the total color temperature of the array light.

[0020] The term “subset” of the plurality of LED light sources needs to be interpreted as two or more neighboring LED light sources of the plurality of LED light sources arranged along a portion P of the length L. This may include examples in which the portion comprises the complete length and the subset comprises all LED light sources of the plurality of LED light sources. In other examples, the subset may comprise at least 25%, preferably at least 50%, more preferably at least 75% of the plurality of LED light sources. Consequently, the portion P may be at least 25%, preferably at least 50%, more preferably at least 75% of the length L.

[0021] One or more of the plurality of LED light sources are arranged at the proximate end of the portion, referred to as the proximate LED light source. One or more of the plurality of LED light sources are arranged at the distal end of the portion, referred to as the distal LED light source. The proximate LED light source and the distal LED light source are thus arranged on opposite ends of the portion. The proximate LED light source is configured to correspond to the color point with the highest CCT (i.e. the primary or secondary proximate correlated color temperature). The distal LED light source is configured to correspond to the color point with the lowest CCT (i.e. the primary or secondary distal correlated color temperature).

[0022] During use the linear light source array is capable of emitting light from the plurality of LED light sources. The controller is configured to simultaneously or individually control the plurality of LED light sources to provide an array light. The light emitted from the linear light source array is provided according to different gradient light effects, providing gradients in correlated color temperature.

[0023] The gradient (also referred to as “gradient light scene”) may be defined by a user or by a predetermined gradient light scene sequence. The user may provide an input to the controller determining the first gradient. The controller controls the first subset of the plurality of LED light sources according to the choice of the user. The gradient light scene may define at least two color points, preferably including the first correlated color temperature at the proximate end or the second correlated color temperature at the distal end. Any intermediate LED light sources comprised by the subset may be controlled according to one or more intermediate light settings, determined by the controller as an interpolation or extrapolation between the at least two color points. The intermediate light settings may comprise a color temperature and luminous flux setting for every LED light source of the subset.

[0024] The controller is configured to control a plurality of LED light sources comprised in the linear light source array according to a gradient light scene. The controller is configured to control each of the plurality of LED light sources and / or sections of the plurality of LED light sources according to the gradient light scene.

[0025] The controller may be configured to control the array light from the linear light source array such that when the total color temperature increases or decreases (during dimming up or dimming down), the total color temperature follows the Black Body Locus, BBL from CTTOT1 to CTTOT2. The absolute difference between CTTOT1 and CTTOT2 may be equal to or more than 1000 K, such as equal to or more than 500K, preferably equal to or more than 300K.

[0026] The total color temperature may follow the Black Body Locus, BBL, linearly or curved according to the BBL, and preferably within 10 SDCM from the BBL. Hence, the controller may be capable of controlling the light emitted from the plurality of LED light sources according to color points defined by the gradient light scene, such that the total color temperature is capable of following the BBL. The controller may be configured to control the array light from the linear light source array, such that when the total color temperature increases or decreases, the CTTOT follows the Black Body Locus, BBL, from CTTOT1 to CTTOT2.

[0027] During dimming up or dimming down, CTTOT may preferably be transitioned in a linear line between two color points arranged substantially on or relatively close to the BBL. Preferably, the CCT may be transitioned in a curved line between the two color points arranged substantially on or relatively close to the BBL, preferably within 10 SDCM (Standard Deviation of Color Matching) from the BBL. More preferably within 5 SDCM from the BBL.

[0028] Additionally, and comparable to what is explained above for the total color temperature, the color temperature of one or more of the LED light sources in the subset may follow the Black Body Locus, BBL, linearly or curved according to the BBL, and preferably within 10 SDCM from the BBL. Hence, the controller may be configured to control each of the LED light sources in the linear light source array such that the light emitting from each of the LED light sources may be varied in a plurality of gradient steps between a first CCT (at the proximate end) and a second CCT (at the distal end), preferably along the BBL. The first CCT may relate to cold white color temperature and the second CCT may relate to warm white color temperature. The gradient steps may follow along the BBL between warm white color temperature and cold white color temperature.

[0029] A gradient light scene is defined by the plurality of LED light sources, which may provide at least two gradient end stops comprising respective color points which may be selected according to a predetermined gradient light scene. Each of the color points of the gradient may be related to the respective gradient end stops. The controller is configured to vary each of the at least two gradient end stops individually, when controlling the plurality of LED light sources. Each of the respective color points may be defined by a respective CCT different from each other. The gradient light scene defines different color points for controlling the plurality of LED light sources during use, such that the plurality of LED light sources provide a first illumination at a predefined distance. The controller may be configured to vary the color points along the linear light source array or part of the linear light source array.

[0030] The controller may be configured to vary each of the at least two gradient end stops relative to each other, such that the correlation between the respective color points of the at least two gradient end stops provide an intermediate gradient stop color point, when controlling the plurality of LED light sources. The intermediate gradient stop may be chosen such that the color point may be moved along the BBL during use. The controller may be configured to vary each of the at least two gradient end stops at essentially the same time relative to each other, when controlling the plurality of LED light sources as such. Each color point can be controlled such that the color point is located along the BBL.

[0031] When providing the first gradient, the proximate LED light source may have a primary proximate luminous flux P 1 , the distal LED light source may have a primary distal luminous flux DL When providing the second gradient, the proximate LED light source may have a secondary proximate luminous flux P2, and the distal LED light source may have a secondary distal luminous flux D2.

[0032] The controller may be configured to vary the luminous flux from at least the proximate LED light source and / or the distal LED light source such that (i) <I»P I - P2 = D I - OD2; or (ii) |<I»P 1 - <I»P2 > |OD1 - OD2|.

[0033] As described above, the first LED light source at the proximate end has a relative higher CCT than the second LED light source at the distal end. During dimming up or dimming down the delta in luminous flux between the first gradient and the second gradient may be the same at the proximate end and at the distal end. Hence, the delta in luminous flux between the first gradient and the second gradient at the proximate LED light source and the delta in luminous flux between the first gradient and the second gradient at the distal LED light source may be substantially the same. Preferably, the luminous flux of all LED light sources of the subset may be increased or decreased equally for every LED light source.

[0034] Alternatively, it may be beneficial during dimming up or dimming down to have increased dimming at the part of the gradient having a relative higher CCT. In other words, to achieve an even further improved gradient effect it may be beneficial to have a higher decrease in the luminous flux of the part of the gradient having a relative higher CCT. For example, in order to dim down to a low total CCT (e.g. below 1500K) it may be needed to dim-down the LED light sources having a higher CCT (towards the proximate end) more than the LED light sources having a lower CCT (towards the distal end). P 1 - <bP2| may be greater than 1.5 |OD1 - D2|, preferably greater than 2 |D1 - D2|, most preferably greater than 3 |<BDl - OD2|.

[0035] The first gradient may comprise a sequence of at least ten different light color points, such that the at least ten different color points have respective CCTs, which decrease from the primary proximate correlated color temperature CCTP1 to the primary distant correlated color temperature CCTD1.

[0036] The decorative gradient light effect may be further enhanced by defining a sequence of at least ten different color points, such that a smooth gradient can be provided from the higher CCT at the proximate end to the lower CCT at the distal end.

[0037] Preferably, the first gradient may define at least eight first color points, more preferably, the first gradient may define at least ten first color points, most preferably the first gradient may define at least ten first color points.

[0038] The first gradient light scene may comprise a sequence of at least ten different light color points, wherein the at least ten different color points may each have respective CCTs. The at least ten different color points may decrease in color temperature from a first color point of the sequence to a last color point of the sequence. For example, the sequence may start at the first color point at 6000K, then according to the sequence defined by the first gradient, decreases the neighboring color point / gradient stop from the first color point to a next color point / gradient stop of 5700K, and further to a next color point / gradient stop of 5400K to a last color point of the sequence of 3000K etc. The differences in CCT between neighboring color points may be in gradient steps of at least 50K, such as at least 100K, preferably at least 300K, most preferably at least 500K.

[0039] What has been described above for the first gradient may equally be applicable to the second gradient. Hence, the second gradient may comprise a sequence of at least ten different light color points, such that the at least ten different color points have respective CCTs, which decrease from the secondary proximate correlated color temperature CCTP2 to the secondary distal correlated color temperature CCTD2.

[0040] The ratio between the difference in primary proximate and primary distal color temperature and the difference in secondary proximate and secondary distal color temperature may be constant or may be in the range of 0.9-1.1, such as in the range of 0.8- 1.2, preferably in the range of 0.5 -1.5.

[0041] In other words, the first color temperature range of the first gradient may be substantially the same or very similar to the second color temperature range of the second gradient. For example, if the difference between the primary proximate color temperature and the primary distal color temperature is 3000K, then the difference between the secondary proximate color temperature and the secondary distal color temperature may preferably also be 3000K, or may be in the range of 2700K-3300K.

[0042] This provides a dimmable gradient light effect for which the color temperature may be varied evenly and proportionally across the gradient, but the color temperature range stays within a predefined range. Hence, even when dimmed, the second gradient still provides an attractive gradient light effect.

[0043] Preferably, the difference between the primary proximate color temperature and the primary distal color temperature may be equal to or greater than lOOOK (more preferably 1200K, most preferably 1500K), and / or the difference between the secondary proximate color temperature and the secondary distal color temperature may be equal to or greater than lOOOK (more preferably 1200K, most preferably 1500K).

[0044] Alternatively or additionally, the difference between the first total color temperature CTTOT1 and the second total color temperature CTTOT2 may preferably be equal to or greater than 500K, more preferably equal to or greater than lOOOK, most preferably equal to or greater than 1500K. Alternatively or additionally, the primary distal color temperature may preferably be equal to or less than 2500K (more preferably 2200K, most preferably 2100K), and / or the secondary distal color temperature may preferably be equal to or less than 2500K (more preferably 2200K, most preferably 2100K).

[0045] Alternatively or additionally, the primary proximate color temperature may preferably be equal to or greater than 3000K (more preferably 3500K, most preferably 3800K), and / or the secondary proximate color temperature may preferably be equal to or greater than 3000K (more preferably 3500K, most preferably 3800K).

[0046] In other words, the color temperature range of one of the first gradient light scene or the second gradient light scene may be at least lOOOK, or the lowest CCT in one of the first gradient light scene or the second gradient light scene may be at most 2500K or the highest CCT in one of the first gradient light scene or the second gradient light scene may be at least 3000K.

[0047] Hence, the controller is configured to vary the parameters of the gradient light scenes in a large range of values, thereby enabling sophisticated and varied dimmable gradient light effects.

[0048] The absolute difference between the primary distal color temperature and the secondary proximate color temperature may preferably be equal to or greater than 500K, more preferably equal to or greater than 700K, most preferably equal to or greater than lOOOK.

[0049] In other words, the first gradient and the second gradient may be chosen such that there is an overlap in the first color temperature range and the second color temperature range. Hence, the color temperatures rendered by the first gradient and the second gradient may not be entirely different from each other.

[0050] The second gradient light scene may define at least ten second color points different from each other, wherein at least one of the at least ten second color points may be different than at least one of the at least ten first color points, such that the plurality of LED light sources provides a second array light. Preferably at least 5 second color points, more preferably at least 8 second color points, most preferably at least 10 second color points may be different from each other.

[0051] The length L of the linear light source may be at least 0.5m, preferably at least 0.7m, more preferably at least Im, most preferably at least 1.5m. The linear light source array may comprise at least 10 LED light sources, preferably at least 20 LED light sources, more preferably at least 40 LED light sources, most preferably at least 50 LED light sources.

[0052] Long linear light sources and / or linear light sources comprising a significant number of LED light sources may be most suitable to render the gradient light effects as described above. Longer linear light sources or linear light sources comprising a higher number of LED light sources provide more opportunities to, for example, render gradient light effects having more color points or gradient light effects being rendered on (partly) different portions of the linear light source. Hence, thereby also improving the decorative light effects.

[0053] Each LED light source of the plurality of LED light sources may comprise (i) a combination of a Red LED, a Green LED and a Blue LED, (ii) a combination of a warm white LED and a cool white LED, or (iii) a combination of a white LED, a Red LED, a Green LED and a Blue LED, and the controller may be configured to control the individual LEDs or the combination of LEDs of each LED light source.

[0054] Hence, each LED light source of the plurality of LED light sources may comprise at least one first LED die configured to emit a first light having a first dominant peak wavelength in a red wavelength range, and at least one second LED die configured to emit a second dominant peak wavelength of green wavelength range, and at least one third LED die configured to emit a dominant peak wavelength of blue wavelength range, such that said controller may be capable of controlling said luminous flux from each of the first, second and third LED die in a LED light source, and a correlation of the respective contributions of the first, second and third light defines a color point emitting from the LED light source.

[0055] Each LED light source in the linear light source array may comprise one or more LED dies. At least one first LED die may be configured to emit a red wavelength range having a dominant peak wavelength of reddish light, for example a wavelength range within 625 nm-750 nm having a dominant. At least one second LED die may be configured to emit a green wavelength range having a dominant peak wavelength of greenish light, for example a wavelength range within 500 nm - 565 nm having a dominant peak wavelength. At least one third LED die configured to emit a blue wavelength range having a dominant peak wavelength of blueish light, for example a wavelength range within 450nm - 485 nm having a dominant peak wavelength. Further LED dies may be configured to emit one or more wavelength ranges having dominant peak wavelengths, different than the first, second and third LED die having wavelength range with dominant peak wavelength. A spectral width of LEDs may be in the order of 20 nm to 50 nm. A color point may be defined by a dominant peak wavelength provided by an LED light source. An intermediated color point may be defined by the contribution of two or more dominant peak wavelengths provided by two or more LED light sources. The controller is configured to control the CCT of the perceived illumination at the predefined distance during use, when transition from the first gradient light scene to the second gradient light scene or vice versa.

[0056] Each LED light source of the plurality of LED light sources may comprise at least one fourth LED die configured to emit a fourth white light having a fourth CCT such that said controller may be capable of controlling the total CCT by varying the respective contribution of the fourth light.

[0057] Alternatively, each LED light source of the plurality of LED light source may comprise at least two LED dies configured to emit white light. A first LED die may be configured to emit warm white light (e.g. light having a correlated color temperature in the range of 1500-3500K) and a second LED die may be configured to emit cool / cold white light (e.g. light having a correlated color temperature in the range of 3500-8000K).

[0058] In a further aspect, the invention provides a lighting system comprising the above-described controller and one or more luminaires, each luminaire of the one or more luminaires comprises the linear light source array.

[0059] Each luminaire may comprise one or more linear light source arrays. The one or more linear light source arrays may be arranged on a flexible PCB and / or in a flexible tube or similar in a predetermined length. The linear light source array may extend linearly in one direction or may extend in more directions when for example being bent.

[0060] Each luminaire may comprise a housing and a light exit window.

[0061] The luminaire may comprise a housing, which may be the external casing or enclosure of the luminaire. The housing may be made of various materials, such as metals, polymers, or glass. The housing may be monolithic or may comprise multiple elements or parts which may be assembled or joined.

[0062] The light exit window of the luminaire may be the surface of the luminaire through which the electromagnetic radiation emitted by the plurality of LED light sources is directed to the exterior of the luminaire. The linear light source array may be arranged within the luminaire to emit light towards the light exit window. The light exit window may be an optical element such as a lens or a diffuser. The light exit window may be configured such that the light emitted by the linear light source array is configured to exit on one side of the luminaire.

[0063] In other words, the light exit window may be dimensioned and positioned such that the angle of the light emitted by the luminaire may preferably be less than 180°, more preferably less than 120°, most preferably less than 90°, measured in a direction perpendicular to the length of the luminaire. In examples in which the housing has a rectangular or square cross section, the light exit window may be arranged on one of the four surfaces of the rectangle or square. In examples in which the housing has a substantially circular, semi-circular, or oval cross section, the light exit window may be arranged on a portion of circumference of less than 180°, more preferably less than 120°, most preferably less than 90°.

[0064] Such a luminaire may be positioned with its light exit window towards a surface, such as towards a wall or a ceiling, at a certain distance to the surface. The array light may be emitted towards said surface, hence providing indirect illumination via the surface.

[0065] At least luminaire of the one or more luminaires may comprise a stand for arranging the luminaire on a support surface. The stand may be configured to be mounted at one end of the linear light source array such that the length L of the linear light source array is positioned in a substantially vertical direction.

[0066] A luminaire enabling the linear light source array to be arranged in a vertical direction may provide additional options for positioning the luminaire to the user, such as next to a bed or next to a display. The luminaire may further provide more nature-like gradient lighting effects, such as a rising or setting sun effect.

[0067] The controller may further comprise or may be functionally coupled to a user interface. The control system may also be configured to receive and execute instructions from 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.

[0068] Hence, the control system may (also) be configured to be controlled by an App on a remote device. The lighting system may also comprise means for communicating with other systems or devices, such as on the basis of Bluetooth, Thread, WIFI, LiFi, ZigBee, BLE or WiMAX, or another wireless technology. To this end, the luminaire may comprise an antenna, a receiver, a transmitter, or a transceiver. The luminaire may execute an action in a “mode” or “operation mode” or “mode of operation” or “operational mode”. The term “operational mode may also be indicated as “controlling mode”. 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”. This does not exclude that the luminaire 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.

[0069] However, a control system may be available, that is adapted to provide at least the controlling mode. Would other modes be available, the choice of such modes may especially be executed via a user interface, though other options, like executing a mode in dependence of a sensor signal or a (time) scheme, may also be possible.

[0070] It is noted that the invention relates to all possible combinations of features recited in the claims.

[0071] BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0073] Figs, la and lb schematically depict aspects of the control of the linear light source array;

[0074] Fig. 2 illustrates a controllable CCT in a CIE color space as well as a controller according to the invention;

[0075] Fig. 3 illustrates additional aspects of a controllable CCT in a CIE color space;

[0076] Fig. 4 schematically depicts an exemplary linear light source array which the controller according to the invention is configured to control; and

[0077] Fig. 5 shows a lighting system according to the invention.

[0078] The schematic drawings are not necessarily to scale.

[0079] DETAILED DESCRIPTION

[0080] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled person.

[0081] Figs, la and lb schematically depict a linear light source array 20 and a controller 1. The linear light source array comprises a plurality of LED light sources 210-220 arranged along a length L of the linear light source array 20. The plurality of LED light sources 210-220 are configured to, in operation and in combination, provide an array light having a total color temperature CTTOT and a total luminous flux <I»TOT.

[0082] The controller 1 is configured to individually control the plurality of LED light sources 210-220 to provide a first gradient in correlated color temperature on at least a first subset of the plurality of LED light sources arranged along portion P of the length L. The P has a proximate end 23 and a distal end 24 opposite the proximate end 23. The first gradient ranges from a proximate LED light source 231 of the subset to a distal LED light source 241 of the subset. The proximate LED light source 231 is located at the proximate end 23 having a primary proximate correlated color temperature CCTP1 and the distal LED light source 241 is located at the distal end 24 having a primary distant correlated color temperature CCTD1. The first gradient, i.e. the first array light emitted by the subset, has a first total correlated color temperature CTTOT1 and a first total luminous flux TOTl.

[0083] The controller is configured to individually control the plurality of LED light sources 210-220 to transition to a second gradient in correlated color temperature provided on the subset of the plurality of LED light sources. The second gradient ranges from the proximate LED light source 231 to the distal LED light source 241. The proximate LED light source 231 has a secondary proximate correlated color temperature CCTP2 , and the distal LED light source 241 has a secondary distal correlated color temperature CCTD2. The second gradient, i.e. the second array light emitted by the second subset, has a second total correlated color temperature CTTOT2 and a second total luminous flux TOT2.

[0084] Fig. la shows an example in which the portion P extends along the whole length L of the linear light source array 20 and the subset comprises all LED light sources of the plurality of LED light sources. Fig. lb depicts an example in which the portion P comprises only a certain portion of the length L and only a certain subset of the plurality of LED light sources.

[0085] It should be noted that Figs, la and lb depict merely two examples of different ways how a controller 1 may control a linear light source array 20, and that the skilled person is able to design alternatives without departing from the scope of the appended claims. Figs. 2 and 3 illustrate a controllable transition from a first gradient light scene to a second gradient light scene relative to the CIE color space 5. A controller 1 is shown schematically as an insert on Fig. 2. The controller 1 is configured to control the plurality of LED light sources 210-220 in the linear light source array 20, as illustrated in Fig. 1. The controller 1 is configured to control the settings of a plurality of color points by driving each of the LED light sources 210-220 separately in the linear light source array 20.

[0086] The controller 1 is configured to receive an input indicative of a user selection of the first gradient light scene, which may comprise a sequence of at least ten different light color points. The user may use a user interface 4, where the user can choose a first gradient light scene. The gradient light scene may be chosen to be a white light, which follows the Black Body Locus, BBL, 13 illustrated on Fig. 2 as a dotted line in a CIE 1931 color space 5. The correlated color temperature, CCT, may be varied along the BBL 13, such that the total CCT of the array light increases or decreases.

[0087] A white light having a first CCT 2 may relate to warm white color temperature and a white light having a second CCT 3 may relate to cold white color temperature. The user may set the first gradient light scene by varying the position of a sliding contact 41, illustrated as a sliding contact in a potentiometer. Alternatively, a user interface 4 related to a smart phone or similar user interfaces may be employed.

[0088] The user may choose a first gradient light scene having a CCT between warm white and cold white. The controller 1 controls the plurality of LED light sources 210-220 according to a first gradient light scene.

[0089] The controller 1 subsequently controls the plurality of LED light sources 210- 220 according to a second gradient light scene different to the first gradient light scene. The second gradient light scene may also be chosen by the user. Alternatively, the second gradient light scene may be chosen by a predetermined lighting sequence. The first gradient light scene and the second gradient light scene may be part of a dynamic gradient light scene. The dynamic gradient light scene may change according to the predetermined lighting sequence. The second gradient light scene may comprise a sequence of at least ten different light color points. The user may use a user interface 4, where the user can choose a second gradient light scene.

[0090] The second gradient light scene may define second color points for the plurality of LED light sources 210-220. The second color points are (at least partly) different from the first color points. The controller 1 is configured to select the setting for the second gradient light scene. The controller 1 varies the plurality of LED light sources 210-220 from having a first gradient light scene setting to the second gradient light scene setting through a first transitioning from the first gradient light scene to the second gradient light scene.

[0091] The controller 1 is capable of varying the luminous flux from each of the plurality of LED light sources 210-220, such that during use the controller 1 is capable of increasing a total luminous flux while increasing a total color temperature, or capable of decreasing a total luminous flux while decreasing a total color temperature of the array light.

[0092] The array light from the linear light source array 20 can be controlled, such that when the total CCT 14 of said array light increases or decreases, the total CCT 14 of the array light may follow the Black Body Locus, BBL 13 from a first total color temperature CTTOT1 to a second total color temperature CTTOT2, wherein a gradient step between CTTOT1 and CTTOT2 is equal to or more than a 500K.

[0093] The array light from the linear light source array 20 is capable of being controlled such that plurality of LED light sources 210-220 arranged on the linear light source array 20 are capable of increasing the total luminous flux of the array light, when the total CCT increases. The array light from the linear light source array 20 is capable of being controlled such that plurality of LED light sources arranged 210-220 on the linear light source array are capable of decreasing the total luminous flux of the array light, when the total CCT of the decreases.

[0094] The plurality of LED light sources 21-26 may be capable of being controlled according to the first gradient light scene. The first gradient light scene may be defined by a sequence of a predetermined numbers of light color points, such that the color points have respective CCTs. The CCT of each of the color points related to the first gradient light scene increases from a first color point CCTP1 of the sequence to a last color point CCTD1. The differences in CCT between adjacent color points may be predetermined, for example at least 300K.

[0095] The controller 1 is configured to control the plurality of LED light sources 21- 26 according to a second gradient light scene. The second gradient light scene defines that at least one of the predetermined color points CCT is increased relative to the first gradient light scene, such that the total color temperature is increased. The second gradient light scene defines that at least one of the predetermined light color points CCT is decreased, such that the total color temperature is decreased.

[0096] Fig. 3 shows a magnified cutout of the CIE color space 5, showing especially the CCT lines crossing the BBL 13 which are referred to in degree of Kelvin. The cutout shows multiple CCT lines at 5000K, 3333K, 2500K, 2000K and 1500K. These CCT lines are merely examples of possible color temperatures and are shown for illustration purposes only.

[0097] The controller 1 is capable of controlling the linear light source array, such that the total color temperature of the array light increases or decreases. The total color temperature color point 8 changes position, such that the total CCT of the array light is increased or decreased (i.e. along the BBL 13) while dimming up or dimming down, which is illustrated with the arrow 18 following the BBL 13 in Fig. 3. The controller 1 may vary the light emitted by the plurality of LED light sources such that the total color temperature color point 8 is moving on or along the BBL 13 during use. The total color temperature color point 8 changes position (i.e. the total CCT is increased or decreased) during transition from the first gradient light scene to the second gradient light scene, and vice versa.

[0098] When rendering the first gradient, the proximate LED light source has a primary proximate correlated color temperature CCTP1, and the distal LED light source has a primary distant correlated color temperature CCTD1. In the depicted example, CCTP1 is 5000K and CCTD1 is 2000K. CCTP1 is thus 3000K higher than CCTD1. The first gradient further has a first total color temperature CTTOT1 depicted along the BBL 13.

[0099] When rendering the second gradient, the proximate LED light source has a secondary proximate correlated color temperature CCTP2, and the distal LED light source has a secondary distal correlated color temperature CCTD2. In the depicted example, CCTP2 is 3333K and CCTD2 is 1500K. CCTP2 is thus approximately 1800K higher than CCTD2. The second gradient further has a second total color temperature CTTOT2 depicted along the BBL 13.

[0100] The second total color temperature CTTOT2 is lower than the first total color temperature CTTOT1. Hence, Fig. 3 depicts an example in which the controller 1 is performing dimming down of the array light and will have simultaneously decreased the second total luminous flux of the array light to 80% or less of the first total luminous flux.

[0101] Fig. 4 schematically illustrates a linear light source array 20 to be controlled by a controller 1 according to the invention. The linear light source array 20 comprises a plurality of LED light sources 210-220. The plurality of LED light sources 210-220 may be arranged on a substrate 30. The substrate 30 may be a PCB. The linear light source array 20, and more particularly the substrate 30, further comprises a proximate end 23,25 and a distal end 24,26 opposite to the proximate end 23,25.

[0102] The linear light source array 20 may be comprised by a luminaire 2 having a housing 21 and a light exit window 22. The housing 21 may be a tubular housing, such as to form a tubular light emitting device, or may be another type of housing 21 to form another, differently shaped, luminaire 2. The light exit window 22 may be configured such that the light emitted by the linear light source array 20 can only exit towards one side of the luminaire 2. To this end, the linear light source array may be positioned such that the emitted light is directed (directly or indirectly) towards the light exit window. In other words, the angle of the light emitted from the luminaire 2 may be limited by the dimensions and position of the light exit window 22 and the elements of the housing 21. The light exit window 22 may be transparent or light transmissive, while the housing 21 may be opaque and impervious to light. The housing 21 may be provided with a proximate end cap 31 and an opposite distal end cap 32. The end caps 31 and 32 may enclose the proximate and distal ends, respectively. At least one of the end caps 31 and 32 may comprise an electrical connection (not shown) for connecting the linear light source array 20, and thus the plurality of LED light sources 210-220, to a power source, such as mains.

[0103] Each LED light source of the plurality of LED light sources 210-220 comprises at least one LED die. A first LED die may be configured to emit a first light having a first dominant peak wavelength in a red wavelength range. A second LED die may be configured to emit second light having a second dominant peak wavelength in a green wavelength range. A third LED die may be configured to emit a third light having a third dominant peak wavelength in a blue wavelength range. The controller controls the luminous flux from each of the first, second and third LED die in each one of the LED light sources or a plurality of first, second and third LED die in the LED light sources 210-220. When correlating the respective contributions of the first, second and third light, the correlated light may provide an intermediated color point emitting from the LED light source.

[0104] The LED light source array 20, which is illustrated in Fig. 4, may comprise a first LED die configured to emit a first white light having a first CCT. The LED light source may also comprise a second LED die configured to emit a second white light having a second CCT. Hence, each LED light source of the plurality of LED light sources may comprise two LED dies configured to emit white light of different respective CCTs. A first LED die may be configured to emit white light having a first CCT being warm white light (e.g. light having a correlated color temperature in the range of 1500-3500K) and a second LED die may be configured to emit white light having a second CCT being cool / cold white light (e.g. light having a correlated color temperature in the range of 3500-8000K). The controller 1 controls the correlated CCT varying the respective contribution of the first and second light. The controller 1 may be configured to vary a luminous flux from at least two LED light sources of the plurality of LED light sources 210-220, such that the controller is capable of increasing or decreasing the total luminous flux.

[0105] Fig. 5 shows an exemplary lighting system comprising the above-described controller 1 and a luminaire 2 comprising the linear light source array 20 as described above. The luminaire 2 comprises a linear light source array 20 of individually controllable light sources 210-220. The luminaire 2 or the linear light source array 20 may further comprise a communication unit 27 and a processing unit 28 for controlling the array of individually controllable light sources 210-220. The processing unit 28 (e.g. a microprocessor, circuitry, a microchip, etc.) may be configured to receive lighting control commands from a lighting control device (e.g. the controller 1) via the communication unit 27 (e.g. via Zigbee, Bluetooth, Wi-Fi, 4G, Ethernet, etc.), and control the array of individually controllable light sources 210-220 based on the lighting control commands. The lighting control commands may comprise control instructions for controlling the plurality of LED light sources 210-220 of the linear light source array 20 according to light settings (e.g. a lighting control value indicative of the colour (temperature), brightness (i.e. luminous flux), saturation, beam size / angle, etc.). The luminaire 2 or the linear light source array 20 may further comprise a memory 29.

[0106] The controller 1 may comprise a processing unit 16, a memory 18 and a communication unit 14 for communicating with the luminaire 2 and / or the linear light source array 20. In the example of Fig. 5, the control unit 1 is separated from luminaire 2 and the linear light source array 20. The controller 1 may be a separate device or it may be integrated into another device such as a mobile phone or tablet. However, the controller 1 may in other examples also be integrated with the luminaire 2 and / or the linear light source array 20.

[0107] The controller 1 may be configured to communicate with the processing unit 16 using a lighting control command. The lighting control command may, for example, comprise a light setting and the processing unit 16 may control the array of individually controllable light sources 210-220 accordingly. Alternatively, a light setting may be stored in the memory 18 and the processing unit 16 may retrieve the associated light setting from the memory 18 when the lighting control command from the controller 1 is received.

[0108] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer or processing unit. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0109] Aspects of the invention may be implemented in a computer program product, which may be a collection of computer program instructions stored on a computer readable storage device which may be executed by a computer. The instructions of the present invention may be in any interpretable or executable code mechanism, including but not limited to scripts, interpretable programs, dynamic link libraries (DLLs) or Java classes. The instructions can be provided as complete executable programs, partial executable programs, as modifications to existing programs (e.g. updates) or extensions for existing programs (e.g. plugins). Moreover, parts of the processing of the present invention may be distributed over multiple computers or processors or even the ‘cloud’.

[0110] Storage media suitable for storing computer program instructions include all forms of nonvolatile memory, including but not limited to EPROM, EEPROM and flash memory devices, magnetic disks such as the internal and external hard disk drives, removable disks and CD-ROM disks. The computer program product may be distributed on such a storage medium, or may be offered for download through HTTP, FTP, email or through a server connected to a network such as the Internet.

Claims

CLAIMS:

1. A controller (1) for controlling a linear light source array (20), wherein the linear light source array (20) comprises a plurality of LED light sources (210-220) arranged along a length L of the linear light source array (20), the plurality of LED light sources (210- 220) being configured to, in operation and in combination, provide an array light having a total color temperature CTTOT and a total luminous flux <I»TOT, wherein the controller (1) is configured to individually control the plurality of LED light sources (210-220) to: provide a first gradient in correlated color temperature on at least a subset of the plurality of LED light sources arranged along a portion P of the length L, the portion P having a proximate end (23) and a distal end (24) opposite the proximate end (23), the first gradient ranging from a proximate LED light source (231) of the subset to a distal LED light source (241) of the subset, wherein the proximate LED light source (231) is located at the proximate end (23) having a primary proximate correlated color temperature CCTP1, wherein the distal LED light source (241) is located at the distal end (24) having a primary distal correlated color temperature CCTD1, wherein CCTP1 > CCTD1 + 500K, and wherein the first gradient has a first total correlated color temperature CTTOT1 and a first total luminous flux TOTl; transition to a second gradient in correlated color temperature provided on the subset of the plurality of LED light sources, the second gradient ranging from the proximate LED light source (231) of the subset to the distal LED light source (241) of the subset, wherein the proximate LED light source (231) has a secondary proximate correlated color temperature CCTP2, wherein the distal LED light source (241) has a secondary distal correlated color temperature CCTD2, wherein CCTP2 > CCTD2 + 500K, and wherein the second gradient has a second total correlated color temperature CTTOT2 and a second total luminous flux <bTOT2; and wherein(i) CCTP2 < CCTP1 - 500K and / or CCTD2 < CCTD1 - 500K, and whereinCTTOT2 < CTTOT1 - 500K and OTOT2 < 0.8 OTOT1; or(ii) CCTP2 > CCTP1 + 500K and / or CCTD2 > CCTD1 + 500K, and whereinCTTOT2 > CTTOT1 + 500K and OTOT2 > 1.2 OTOT1.

2. The controller (1) according to claim 1, wherein, when providing the first gradient, the proximate LED light source (231) has a primary proximate luminous flux P 1 and the distal LED light source (241) has a primary distal luminous flux D1, wherein, when providing the second gradient, the proximate LED light source (231) has a secondary proximate luminous flux P2and the distal LED light source (241) has a secondary distal luminous flux D2, wherein said controller (1) is configured to vary the luminous flux from at least the proximate LED light source (231) and / or the distal LED light source (241) such that(i) OP1 - OP2 = D1 - OD2; or(ii) |<I»P 1 - OP2| > |OD1 - OD2|.

3. The controller (1) according to any one of the preceding claims, wherein the first gradient and / or the second gradient comprises a sequence of at least ten different light color points, such that the at least ten different color points have respective CCTs, which decrease from the primary proximate correlated color temperature CCTP1 to the primary distal correlated color temperature CCTD1 and / or from the secondary proximate correlated color temperature CCTP2 to the secondary distal correlated color temperature CCTD2.

4. The controller (1) according to any one of the preceding claims, wherein the controller is further configured to individually control the plurality of LED light sources (210-220) to transition from the first total correlated color temperature CTTOT1 of the first gradient to the second total correlated color temperature CTTOT2 of the second gradient along a line arranged within 10 SDCM from the black body line.

5. The controller (1) according to claim 4, wherein the line is a curved line.

6. The controller (1) according to any one of the preceding claims, wherein the controller is further configured to individually control each LED light source of the subset to transition from the first gradient to the second gradient along a line arranged within 10 SDCM from the black body line.

7. The controller (1) according to any one of the preceding claims, wherein 0.9 < (CCTP1-CCTD1) / (CCTP2-CCTD2) < 1.1.

8. The controller (1) according to any one of the preceding claims, wherein |CCTP1 - CCTD1| > lOOOK and / or |CCTP2 - CCTD2| > lOOOK, ICTTOTI -CTTOT2| > lOOOK,CCTD1 < 2500K and / or CCTD2 < 2500K, andCCTP1 > 3000K and / or CCTP2 > 3000K.

9. The controller (1) according to any one of the preceding claims wherein |CCTD1 - CCTP2| > 500K.

10. The controller (1) according to any one of the preceding claims wherein L is at least 0.7m. and wherein the linear light source array (20) comprises at least 20 LED light sources.

11. The controller (1) according to any one of the preceding claims, wherein each LED light source of the plurality of LED light sources (210-220) comprises (i) a combination of a Red LED, a Green LED and a Blue LED, (ii) a combination of a warm white LED and a cool white LED, or (iii) a combination of a white LED, a Red LED, a Green LED and a Blue LED, and wherein the controller (1) is configured to control the individual LEDs or the combination of LEDs of each LED light source.

12. A lighting system (100) comprising the controller (1) according to any one of the preceding claims and one or more luminaires (2), wherein each luminaire (2) of the one or more luminaires comprises the linear light source array (20).

13. The lighting system (100) according to claim 12, wherein each luminaire (2) comprises a housing (21) and a light exit window (22).

14. The lighting system (100) according to claim 13, wherein the light exit window (22) is configured such that the light emitted by the linear light source array (20) is configured to exit on one side of the luminaire (2).

15. The lighting system (100) according to any one of claims 12-14, wherein at least one luminaire (2) of the one or more luminaires (2) comprises a stand for arranging the luminaire on a support surface, wherein the stand is configured to be mounted at one end of the linear light source array (20) such that the length L of the linear light source array is positioned in a substantially vertical direction.

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