Patent Grant
12038169
This application is the U.S. National Phase application under 35 U.S.C. § 371 of International Application No. PCTEP2022/058143, filed on Mar. 28, 2022, which claims the benefit of European Patent Application No. 21166731.6, filed on Apr. 1, 2021. These applications are hereby incorporated by reference herein.
The present invention relates to a light emitting device adapted for creating natural dynamic lighting effects. More particularly, the present invention relates to a light emitting device comprising at least a first light source and a second light source, the first light source and the second light source being adapted for, in operation, emitting light, at least one first lens associated with the first light source, and at least one second lens associated with the second light source.
Currently, there is a high interest in bringing the positive aspects of natural light into an office, retail or home environment. Positive aspects of natural light, such as outdoor light or sun light, are e.g. dappled light created by sunlight shining through the leaves of trees or the reflected light from a water surface on the wall of a house. These dynamic light effects can be applied indoors to create a more attractive, lively atmosphere.
A known way to apply dynamic lighting is to project specific content on a wall. The projection of visual content on a wall has been investigated for at least a century. A relatively new way of projection is the use of ultra-short throw (UST) LCD projectors which can be used at a fairly close distance (less than 1 m) to the wall. These projectors give a crisp image on the wall, however at a high cost. Another disadvantage is noise generated by a fan needed to cool the device.
US 2016/227618 A1 describes a lighting system with an array of lighting elements which provide light in different directions. The intensity of the lighting elements is controlled by means of a controller in dependence on a time-varying parameter related to at least one of a position of a light emitting or light reflecting body, and an intensity, color or color temperature of the light emitted or reflected by the body, such that the system can simulate directional sunlight.
It is thus desired to provide a light emitting device with which the above-mentioned disadvantages are reduced or even overcome entirely.
It is an object of the present invention to provide a light emitting device of the type with which natural dynamic lighting effects may be created, which light emitting device is cheap to produce and which do not produce noise when in operation.
It is a further object of the present invention to provide such a light emitting device which may be used at a fairly close distance to a surface to be illuminated, and which is capable of providing a high quality image on the surface to be illuminated.
According to a first aspect of the invention, these and other objects are achieved by means of a light emitting device comprising at least one cluster of light sources and lenses, the at least one cluster comprising at least a first light source and a second light source, the first light source and the second light source being adapted for, in operation, emitting first respectively second light, at least one first lens associated with the first light source, and at least one second lens associated with the second light source, where the first lens is configured to create a first illuminance pattern in a plane P and the second lens is configured to create a second illuminance pattern in the plane P, where the first light source and the first lens and the second light source and the second lens, respectively, are arranged in a predefined distance D from the plane P, the predefined distance D being measured in a direction extending perpendicular to the plane P, where the first light source and the first lens are arranged such that during operation an average emission direction of the first light is along a first axis, and the second light source and the second lens are arranged such that during operation an average emission direction of the second light is along a second axis, where the first light source and the first lens and the second light source and the second lens, respectively, are oriented such that the first axis and the second axis extend at an angle ϕ with a plane H extending in parallel with and in the predefined distance D from the plane P and that the first axis and the second axis intersect at or in the plane P, wherein the first light source and the first lens and the second light source and the second lens, respectively, are further arranged and on a straight line extending in parallel with the plane P and perpendicular to the direction in which the distance D is measured, wherein the first lens and the second lens are freeform lenses, and wherein the first illuminance pattern and the second illuminance pattern are mutually different illuminance patterns, each illuminance pattern comprising at least three first and at least three second areas, wherein the first areas have a first color and the second areas have a second color different from the first color and/or the first areas comprise a brightest area having a brightness Bb and the second areas are dark areas of a brightness Bd, and wherein Bd<=0.25*Bb, preferably Bd<=0.15*Bb, such as Bd<=0.1*Bb. The plurality of first areas is at least three, but preferably is more than three, such as four, five, ten, or more than twenty. The plurality of second areas is at least three, but preferably is more than three such as four, five, ten, or more than twenty. First and second color are to be understood as also comprising first and second color temperature and correlated color temperature. The average emission direction of a (first and second) light beam is to be understood as the direction towards the center of the whole area, comprising both first and second areas, illuminated by said light beam.
Thereby, and in particular by providing that the first lens is configured to create a first illuminance pattern in a plane P and the second lens is configured to create a second illuminance pattern in the plane P, as well as by providing that the first light source and the first lens and the second light source and the second lens, respectively, are arranged as described above, a light emitting device of the type with which natural dynamic lighting effects of a high quality as perceived by a viewer may be created, which light emitting device is structurally extremely simple and comprises very few components as compared to the prior art solutions. Such a light emitting device is cheap to produce and further does not produce noise when in operation.
The light emitting device could have the feature that the illuminance pattern comprises at least one first area surrounded by a plurality of second areas and at least one second area surrounded by a plurality of first areas. Thus an illuminance pattern with an acceptable, minimal degree of variation in illuminance is created.
Furthermore, and in particular by providing that the first light source and the first lens and the second light source and the second lens, respectively, are arranged in the distance D, and that the first axis and the second axis extend at an angle ϕ, as described above, it is enabled that such a light emitting device may be used at a fairly close distance to a surface to be illuminated, and is still capable of providing a high-quality image on the surface to be illuminated.
In an embodiment, the size of at least one of the first lens and the second lens is chosen in dependence of the size of a light emitting area of at least one of the first light source and the second light source.
Thereby, it becomes possible to scale the size of the optics, particularly the lenses, depending on the size of the light emitting area of the associated light source. This in turn provides for a light emitting device providing a sharper output of a particularly high quality.
In an embodiment, the angle ϕ is an acute angle with the plane H extending in parallel with and in the predefined distance D from the plane P.
Thereby, it is enabled that the light emitting device may be used at a particularly close distance to a surface to be illuminated and that it is still capable of providing a high-quality image on the surface to be illuminated.
In an embodiment, the predefined distance D is equal to or less than one meter.
Thereby, it becomes possible to use the light emitting surface instead of a more complex and expensive projector type, such as ultra-short throw (UST) LCD projectors.
In an embodiment, the first light source and the second light source are configured to, in operation, emitting light of mutually different colors.
Thereby a light emitting device is provided with which a wider range of visual effects may be obtained as compared to if the first light source and the second light source were configured to emit light of the same or similar color.
In an embodiment, the first light source and the second light source are configured to be tunable with respect to any one or more of color, color temperature, light intensity and light flux.
Thereby a light emitting device is provided with which a particularly wide range of visual effects may be obtained. For instance, by tuning color and flux of the first light source and the second light source, visual effects may be obtained where colors appear and disappear in time and the illuminance uniformity can vary between highly non-uniform to almost perfectly uniform. Also, by tuning color and flux as a function of time, visual effects similar to, e.g., a cloudy sky where clouds disappear and appear may be obtained.
In an embodiment, the first light source and the second light source are any one of point light sources, an LED, an LED having a light emitting area with a size of 0.1×0.1 mm, an LED having a light emitting area with a size of 0.15×0.15 mm, a plurality of LEDs, an RGB package of LEDs or an RBGW package of LEDs.
For instance, point light sources are preferred for enabling obtaining a particularly sharp pattern. Also, an LED having a square light emitting area SL with a size of 0.1×0.1 mm is preferred for enabling, for a give lens, obtaining a sharper pattern as compared to, e.g., an LED having a light emitting area with a size of 0.15×0.15 mm, which in turn nevertheless still gives an acceptably sharp pattern. A plurality of LEDs, an RGB package of LEDs or an RBGW package of LEDs are all preferred for enabling patterns composed of several—or indeed all—different colors, and thus enabling complex and highly detailed patterns.
In an embodiment, the mutually different first illuminance pattern and second illuminance pattern comprise randomly generated illuminance patterns and mutually complementary illuminance patterns.
Mutually different illuminance patterns or random illuminance patterns provide for a wide range of visual effects which may change over time. Mutually complementary illuminance patterns are particularly preferred for also enabling a constant illuminance pattern in case both the first and second light source is on. Complementary in this respect means that where a first illuminance pattern has first and second areas, the second illuminance pattern is inversed in color and/or brightness, i.e. the first areas of the first illuminance pattern that have a first color and/or are dark are areas with a second color and/or are bright areas in the second illuminance pattern, and the second areas of the first illuminance pattern that have a second color and/or are bright are areas with a first color and/or are dark areas in the second illuminance pattern.
In an embodiment, the first lens and the second lens are made of any one of optical grade PMMA and polycarbonate.
Thereby, particularly robust and durable lenses are provided for, which in turn provides for a light emitting device providing a continuously high-quality light output over a long period of time.
In an embodiment, at least a part of a light exit surface of at least one of the first lens and the second lens comprises any one of optical microstructures and an optical foil.
Thereby a light emitting device is provided with which the uniformity and smoothness of the light output is enhanced.
In an embodiment, the light emitting device further comprises at least one light mixing element arranged and configured to mix light emitted from at least one of the first light source and the second light source.
Thereby a light emitting device is provided with which the light emitted from one or both of the first light source and the second light source may be mixed in order to provide an improved uniformity of the light output.
In an embodiment, at least a part of a light exit surface of the at least one light mixing element comprises any one of optical microstructures and an optical foil.
Thereby a light emitting device is provided with which the uniformity and smoothness of the mixed light output is enhanced.
In an embodiment, the optical microstructures comprise any one or more of lenslets and surface roughnesses.
Thereby a light emitting device is provided with which an improved uniformity and smoothness of the light output may be obtained in a structurally very simple and easy to manufacture manner.
In an embodiment, the at least one cluster further comprises at least one further light source adapted for, in operation, emitting at least one further light and at least one further lens associated with the at least one further light source, where the first light source and the first lens, the second light source and the second lens and the at least one further light source and the at least one further lens, respectively, are arranged in a predefined distance D from the plane P, the predefined distance D being measured in a direction extending perpendicular to the plane P, wherein the first light source and the first lens are arranged such that during operation the average emission direction of the first light is along the first axis, and the second light source and the second lens are arranged such that during operation the average emission direction of the second light is along the second axis, and the at least one further light source and the at least one further lens are arranged such that during operation the emission direction of at least one further light is along at least one further axis, where the first light source and the first lens, the second light source and the second lens and the at least one further light source and the at least one further lens are oriented such that the first axis, the second axis and the at least one further axis extend at an angle ϕ with a plane H extending in parallel with and in the predefined distance D from the plane P, and that the first axis, the second axis and the at least one further axis intersect at or in the plane P, and where the first light source and the first lens, the second light source and the second lens and the at least one further light source and the at least one further lens, respectively, are further arranged and on a straight line extending in parallel with the plane P and perpendicular to the direction in which the distance D is measured.
Thereby, a light emitting device is provided which has a further degree of freedom in designing the resulting image in the plane P, and which is thus more versatile, especially in terms of use possibilities and complexity of the resulting total image in the plane P.
In an embodiment, each cluster comprises N first lenses, M second lenses and, where provided, Q further lenses, where N, M and Q each are an integer being 1 or more, and where N, M and Q may be the same or different.
Thereby, a light emitting device is provided which has several degrees of freedom in designing the resulting image in the plane P, and which is thus much more versatile, especially in terms of use possibilities.
In an embodiment, the first lenses, the second lenses and, where provided, the further lenses are mutually different lenses.
Thereby, a light emitting device is provided which has a further degree of freedom in designing the resulting image in the plane P, especially as two or more different images may be used to form the resulting total image in the plane P.
In an embodiment, the light emitting device further comprises at least two clusters of light sources and lenses.
In an embodiment, the light emitting device further comprises an array of clusters of light sources and lenses.
Thereby, a light emitting device is provided with which a larger area, such as a whole wall or a broad section of a wall, may be illuminated. Furthermore, such a light emitting device allows for varying the density and illuminance of the pixels forming the resulting image in the plane P with position, for instance such as to obtain a more natural transition between various settings.
In an embodiment, the two or more clusters are arranged with a pitch p seen along the straight line extending in parallel with the plane P and perpendicular to the direction in which the distance D is measured, where the pitch p is chosen to be smaller than the size in the direction of the said straight line of the areas illuminated by the respective cluster of the two or more clusters.
Thereby a seamless transition between the areas illuminated by the respective cluster of the two or more clusters is obtained.
The invention further relates to a luminaire or a lamp comprising a housing at least partly accommodating a light emitting device according to the invention.
It is noted that the invention relates to all possible combinations of features recited in the claims.
This and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing embodiment(s) of the invention.
As illustrated in the figures, the sizes of layers and regions are exaggerated for illustrative purposes and, thus, are provided to illustrate the general structures of embodiments of the present invention. This especially applies for the size of the lenses 31-33 and 311, 312, 321, 322, 331, 332, respectively, with respect to the size of the image 5 and 51-53, respectively, in the illustrations of
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.
The first light source 21 and the first lens 31 are arranged on a first axis 41. The second light source 22 and the second lens 32 are arranged on a second axis 42. The first axis 41 and the second axis 42 intersect at a target surface 5. The target surface 5 is a surface which it is desired to illuminate with the light emitting device 1. The target surface 5 may for instance be a wall (as shown on
The first light source 21 and the second light source 22 are arranged in a distance D from a plane P in which the target surface 5 is arranged. The distance D is measured perpendicular to the plane P, i.e. in the direction x illustrated by the coordinate system shown in
The first light source 21 and the first lens 31 and the second light source 22 and the second lens 32 are further arranged on a straight line extending in the direction y illustrated by the coordinate system shown in
The first light source 21 and the second light source 22 may be point light sources, or light sources having a light emitting area with, e.g., a size of 0.1×0.1 mm or 0.15×0.15 mm. The first light source 21 and the second light source 22 may be an LED or a plurality of LEDs, such as an RGB or an RBGW package of LEDs. The first light source 21 and the second light source 22 may be adapted for, in operation, emitting first light respectively second light, said first and second light being of mutually different colors.
The light emitting device 1 comprising at least the combination of the first light source 21 with the first lens 31 for providing first light and the combination of the second light source 22 with the second lens 32 for providing second light, said combinations together may be configured to provide any suitable or desired dynamic pattern on the target surface 5, including a random pattern. The size of the first lens 31 and the second lens 32 may be chosen in dependence of the size of a light emitting area of at least one of the first light source 21 and the second light source 22. The first lens 31 and the second lens 32 may be made of optical grade PMMA or polycarbonate or another suitable material. An example of a first lens 31 and a second lens 32 are shown in more detail in
The first lens 31 and the second lens 32 comprises a light exit surface. A part or all of the light exit surface of the first lens 31 and the second lens 32 may comprise an optical element 81, 82 (cf.
The light emitting device 1 also comprises a further (third) light source 23 adapted for, in operation, emitting light and a further (third) lens 33 associated with the further light source 23. It is noted that the further light source 23 and the further lens 33 are optional features. More than one further light source and associated lens may in principle also be provided. The further light source 23 and the further lens 33 may be of any of the respective types of light sources and lenses described above. The further light source 23 may be of a type emitting light of a color differing from both the first light source 21 and the second light source 22 or being the same as one of the first light source 21 and the second light source 22. The further lens 33 may be different from, both the first lens 31 and the second lens 32.
The further light source 23 and the further lens 33 are arranged on a further axis 43. The further light source 23 and the further lens 33 are oriented such that the further axis 43 intersects the first axis 41 and the second axis 42 at the target surface 5. The further light source 23 and the further lens 33 are arranged in a distance D from the plane P and thus from the target surface 5. The distance D is generally equal to or less than 1 meter. The further light source 23 and the further lens 33 are further arranged in a height h, for instance a height h above a floor surface 6. The height h is typically equal to or less than 2.5 m. The further axis 43 extends at an angle ϕ, such as an acute angle ϕ, with respect to the plane H. The further light source 23 and the further lens 33 are arranged beside the first light source 21 and the first lens 31 and the second light source 22 and the second lens 32, respectively, in the direction y extending in parallel with the plane P and thus with target surface 5. The distance or free space in the direction y between the further lens 33 and the first lens 31 and the second lens 32, respectively, is generally less than 25 mm, such as between 5 and 25 mm. The diameter of the further lens 33 may be between 10 mm and 50 mm.
Turning now to
The light emitting device 10 comprises three clusters 11, 12, 13 of lenses. Each cluster 11, 12, and 13 comprises two light sources and two lenses. The first cluster 11 comprises a first light source 211 and a first lens 311 as well as and a second light source 212 and a second lens 312. The second cluster 12 comprises a first light source 221 and a first lens 321 as well as and a second light source 222 and a second lens 332. The third cluster 11 comprises a first light source 231 and a first lens 331 as well as and a second light source 232 and a second lens 332. In comparison, the light emitting device 1 according to
Generally, each cluster 11, 12, 13 is in principle identical. Generally speaking, each cluster comprises N first lenses, being lenses of a first type, and M second lenses, being lenses of a second type, where N is an integer being 1 or more and where M is an integer being 1 or more, and where N and M may be the same or different. Optionally, each cluster may further comprise Q further lenses, e.g. being lenses of a further type different from the first and second type, where Q is an integer being 1 or more, and where Q may be the same as or different from one or both of N and M.
The light emitting device 10 comprises a light mixing element 91 arranged and configured to mix light emitted from the first light source 211 of the first cluster 11 and a light mixing element 92 arranged and configured to mix light emitted from the second light source 222 of the first cluster. The light mixing elements 91, 92 may be arranged between the respective light source 211, 212 and lens 311, 312 or (as shown on
The first light sources 211, 221 and 231 and the second light sources 212, 222 and 232 of each of the three clusters 11, 12 and 13 are in this embodiment configured to be tunable with respect to color, color temperature, light intensity, light flux or any combination thereof. The light emitting device 10 comprises a controller 7 configured to control the tunable parameter or parameters of the light sources 211, 221, 231, 212, 222 and 232. The controller 7 is thus in a signal transferring relationship with the respective light sources 211, 221, 231, 212, 222 and 232, for instance by use of a wired or wireless connection.
It is also feasible to provide a light emitting device according to the invention with more than three clusters. It is also feasible to provide at least one cluster of a light emitting device according to the invention with more than pairs, such as four, five or six pairs, of light sources and lenses.
A light emitting device according to the invention may also comprise an array of clusters such as the clusters 11, 12, 13 shown in
Turning now to
In the following a number of examples of simulations performed on a light emitting device 1 according to the invention and as described above with reference to
As may clearly be seen, for a given lens 31, 32, the use of light sources 21 and 22 with a light emitting surface area of 0.1×0.1 mm provides a more uniform image with a higher irradiance level as compared to the use of point light sources 21 and 22. On the other hand, the use of point light sources 21 and 22 provides a considerably sharper image with a higher quality as compared to the use of light sources 21 and 22 with a light emitting surface area of 0.1×0.1 mm.
As may clearly be seen, for a given lens 31, 32, the use of light sources 21 and 22 with a light emitting surface area of 0.1×0.1 mm provides an output with a very well defined directionality, and thus provides for a particularly sharp pattern and thus resulting image on the target area 5.
As may clearly be seen from
The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims.
Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21166731 | Apr 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/058143 | 3/28/2022 | WO |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2022/207562 | 10/6/2022 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7458700 | Gordin | Dec 2008 | B2 |
| 8820972 | Mollnow | Sep 2014 | B2 |
| 9631795 | Gordin | Apr 2017 | B2 |
| 9851069 | Michiels | Dec 2017 | B2 |
| 10201056 | Gordin | Feb 2019 | B1 |
| 20030202241 | Blumel | Oct 2003 | A1 |
| 20060245189 | Gordin | Nov 2006 | A1 |
| 20100061090 | Bergman | Mar 2010 | A1 |
| 20140226337 | Timmers et al. | Aug 2014 | A1 |
| 20160227618 | Meerbeek et al. | Aug 2016 | A1 |
| 20210003160 | Haeussler et al. | Jan 2021 | A1 |
| Number | Date | Country |
|---|---|---|
| 2881651 | Jun 2015 | EP |
| 2017144303 | Aug 2017 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20240167662 A1 | May 2024 | US |
