EP4528153A1

EP4528153A1 - Element for a lighting system and lighting system

Info

Publication number: EP4528153A1
Application number: EP23198975.7A
Authority: EP
Inventors: Eugen Rigger
Original assignee: Zumtobel Lighting GmbH Austria
Current assignee: Zumtobel Lighting GmbH Austria
Priority date: 2023-09-22
Filing date: 2023-09-22
Publication date: 2025-03-26
Also published as: WO2025061825A1

Abstract

The present invention provides an element (1) for a lighting system. The element comprises a first part (2) and a second part (3). The first part (2) is made of at least a first material and a second material, the first material and the second material having different expansion coefficients with regard to one or more types of stimuli. The first material and second material are arranged such that a shape of the first part (2) changes from a first shape to a second shape due to an expansion or contraction of the first material and second material caused by an exposure of the element (1) to the one or more types of stimuli. The second part (3) maintains its shape when the element (1) is exposed to the one or more types of stimuli.

Description

The present invention relates to an element for a lighting system and a lighting system comprising such an element.
In the field of lighting, different elements are used in a luminaire or lighting means besides the light source for providing lighting. Lighting means may be the component that is provided in a luminaire to provide a light source of the luminaire. The lighting means may be installed in the luminaire without the possibility of changing the lighting means or with the possibility to replace the lighting means in case the lighting means are defect. The lighting means may for example comprise one or more light emitting diodes (LEDs) as a light source. Lighting means comprising one or more LEDs that may be installed in sockets used for conventional lighting means, such as light bulbs, fluorescent lamps etc., may be referred to as retrofit LED lighting means.
For example, a heat sink may be used in a luminaire or lighting means to deal with heat output by the light source emitting light. Another example of an element used in a luminaire or lighting means besides the light source may be a housing for protecting the light source and an electric circuit of the luminaire or lighting means. A furthermore example is a light guiding unit for guiding light emitted by the light source of the luminaire or lighting means.
Such additional elements add to the production costs of luminaires and lighting means. Namely, a certain shape of such an element, such as a heat sink, required for use in a lighting system, such as luminaire or lighting means, may be bulky for transport and storage and optionally difficult to install in the lighting system. That is, the geometry of the element desired in the installed state at the luminaire or lighting means may be disadvantageous during a manufacturing process and transport of the luminaire or lighting means.
Therefore, it is an object of the present invention to provide an element for a lighting system that overcomes the above-described disadvantages. It is in particular an object of the present invention to provide an improved element for a lighting system that is improved with regard to at least one of transport, storage and installment in the lighting system.
These and other objects, which become apparent upon reading the following description, are solved by the subject-matter of the independent claim. The dependent claims refer to preferred embodiments of the invention.
According to a first aspect of the invention, an element for a lighting system is provided. The element comprises a first part and a second part. The first part is made of at least a first material and a second material. The first material and the second material have different expansion coefficients with regard to one or more types of stimuli. That is, with regard to one or more types of stimuli an expansion coefficient of the first material is different to an expansion coefficient of the second material. The first material and second material are arranged such that a shape of the first part changes from a first shape to a second shape due to an expansion or contraction of the first material and second material caused by an exposure of the element to the one or more types of stimuli. The second part maintains its shape when the element is exposed to the one or more types of stimuli.
It is to be noted that the transition from the first shape to the second shape allows the second shape to provide a different or at least significantly improved function. For example a heat sink that has a large open surface in the second shape provides no or no reasonable surface for cooling as long as it has its first shape in which it is folded in order to require small space.
Since the first part of the element is configured, by comprising the first material and second material, to change its shape from the first shape to the second shape in response to the element being exposed to the one or more types of stimuli, the first shape may be selected or designed to be advantageous with regard to at least one of transport, storage and installment in the lighting system, while the second shape may be selected or designed to be advantageous with regard to the intended function of the element in the lighting system.
For example, assuming that the lighting system is a luminaire and the element is a heat sink for the luminaire, the first shape of the first part of the element may have smaller dimensions compared to the second shape of the element. Namely, the element having smaller dimensions requires less space when being transported or stored in a shelf. Further, the smaller dimensions allows installing the element inside a housing of the luminaire via a smaller opening of the housing. The second shape of the first part of the element having grater dimensions allows increasing the surface of the element, which is advantageous with regard to absorbing heat inside the luminaire, when the element is installed in the luminaire. Thus, the first shape is advantageous with regard to transport, storage and installment in the luminaire, whereas the second shape is advantageous with regard to the intended function of the element (e.g. being a heat sink) in the luminaire.
The size, i.e. one or more dimensions, of the first shape of the first part of the element. may be smaller than the size, i.e. the one or more dimensions, of the second shape of the first part of the element. The second shape of the first part of the element is determined by a function of the element in the lighting system. The first part of the element may be an integral part of the element or comprise two or more sections of the element.
The first material and second material experience different behavior with respect to expansion or contraction when being exposed to the one or more types of stimuli. That is, the first material and second material may differently expand or contract when being exposed to the one or more types of stimuli. Namely, the first material and second material have different expansion coefficients with regard to the one or more types of stimuli.
The second part is configured to be mounted to the lighting system. That is, the second part may be used for installing the element at the lighting system. Therefore it is advantageous that the second part does not structurally change when the element is exposed to the one or more types of stimuli, which means that he second part maintains its shape.
The first material and second material are arranged such that a shape of the first part of the element changes from the first shape to the second shape due to an expansion or contraction of the first material and second material caused by a treatment of the element with the one or more types of stimuli. The one or more types of stimuli may be referred to as "one or more dedicated types of stimuli", because the one or more types of stimuli trigger an expansion or contraction of the first material and second material and, thus, cause the change of the shape of the first part of the element from the first shape to the second shape.
The first material and second material may be such that once the first material and second material have expanded or contracted due to the exposure of the element to the one or more types of stimuli and, thus, the shape of the first part of the element has changed to the second shape, the shape of the first part does not change when the element is exposed again to the one or more types of stimuli. Optionally, this may be the case when the element has been exposed to an amount of the one or more types of stimuli that is greater than a respective threshold.
The term "add-on element" or "extension element" for a lighting system may be used to refer to the element according to the first aspect for a lighting system.
The one or more types of stimuli may comprise at least one of heat, light, ultra-violet radiation, electric current and voltage.
Thus, the first material and the second material may have different expansion coefficients with regard to at least one of heat, light, ultra-violet radiation, electric current and voltage.
For example, in case the first material and the second material have different coefficients with regard to heat, the first material and the second material differently expand or contract when the element is being exposed to heat, e.g. to an amount of heat being greater than threshold. Heat is a form of energy. It may be understood as the thermal energy transferred to the element due to a temperature difference. That is, exposing the element to heat means transferring thermal energy to the element. In other words, this means heating the element, i.e. increasing the temperature of the element. The first material and second material may experience or have different thermal expansion coefficients leading to expansion or contraction depending on heating or cooling the element. The first material and second material may be for example one or more shape memory alloys or polymers. In case the first material and second material are one or more shape memory alloys or polymers, the element may be exposed to one or more temperatures that are greater than discrete threshold temperatures being specific to the first and second material. The one or more temperatures being greater than the discrete threshold temperatures trigger the shape memory effect and, thus, change of the shape of the first part of the element.
For example, in case the first material and the second material have different coefficients with regard to light, the first material and the second material differently expand or contract when the element is being exposed to light, e.g. to light having a light intensity greater than a threshold.
For example, in case the first material and the second material have different coefficients with regard to ultra-violet radiation, the first material and the second material differently expand or contract when the element is being exposed to ultra-violet radiation, e.g. to ultra-violet radiation having a radiant flux greater than a threshold. The term "ultra-violet" may be abbreviated by "UV". The term "ultra-violet light" may be used as a synonym for the term "ultra-violet radiation".
For example, in case the first material and the second material have different coefficients with regard to electric current and/or voltage, the first material and the second material differently expand or contract when the element is being exposed to electric current and/or voltage, e.g. to electric current and/or voltage being greater than a threshold.
The one or more types of stimuli may comprise at least one of heat, light, a radiant flux of ultra-violet radiation, electric current and voltage each being greater than a respective threshold.
Optionally, an exposure of the element to ultra-violet radiation for changing the shape of the first part of the element from the first shape to the second shape may be achieved by exposing the element to daylight, e.g. unwrapping the element from a packaging. In this case, the first material and second material may have different expansion coefficients with regard to daylight, i.e. the ultra-violet radiation contained in day light.
The first material and the second material may be configured, due to their expansion coefficients, to expand or contract in response to the element being exposed to a dedicated amount of a respective stimulus of the one or more types of stimuli for a dedicated period of time. The expansion or contraction of the first material and the second material may be triggered by a respective stimulus of the one or more types of stimuli being greater than a threshold for the respective stimulus.
For example, in case the first material and the second material have different expansion coefficients with regard to heat, the first material and the second material may be configured to expand or contract in response to the element being exposed to a dedicated amount of heat for a dedicated period of time. Thus, in the aforementioned case, the expansion or contraction of the first material and the second material may be triggered by heat being greater than a threshold for the heat. Optionally, the first material and second material may be one or more shape memory alloys or polymers.
The first material and second material having different expansion coefficients with regard to heat may be one or more shape memory polymer laminates. For example, the first material and second material may be two layers of polyurethane, wherein e.g. the first material has strain and the second material is in a normal state (e.g. has no strain). In the aforementioned case, the threshold for the heat may be for example 6o°C. That is, a temperature of 6o°C or greater may trigger the expansion or contraction of the first material and the second material. This temperature may be referred to as "activation temperature". For example, the first material may be an active layer from PHAG5000 based shape memory polyurethane (SMPU) with 100% strain and the second material may be a substrate layer from PBAG600 based polyurethane without deformation. Each of the aforementioned active layer and substrate layer may optionally be 1 mm thick. The threshold for the heat may be selected such that heat being greater than said threshold triggers a shape memory effect of at least one of the first and second material, e.g. of the first material. Exposing the element to a dedicated heat may mean exposing the element to a dedicated temperature, i.e. to a temperature greater than a threshold for the temperature.
For example, in case the first material and the second material have different expansion coefficients with regard to light, the first material and the second material may be configured to expand or contract in response to the element being exposed to a dedicated amount of light for a dedicated period of time. Thus, in the aforementioned case, the expansion or contraction of the first material and the second material may be triggered by a light intensity being greater than a threshold for the light intensity. The first material and the second material having different expansion coefficients with regard to light may optionally be a first material and second material having different expansion coefficients with regard to an increase in temperature. The increase in temperature of the element may be obtained by exposing the element to a light illumination. The first material and second material may be one or more shape memory alloys or polymers. Optionally, the first material and second are one or more shape memory polymer laminates. For example, the first material and second material may be two layers of polyurethane, wherein e.g. the first material has strain and the second material is in a normal state (e.g. has no strain). In the aforementioned case, the threshold for the amount of light may be an amount of light causing an temperature of 60°C or greater. The threshold for the light intensity may be selected such that a light intensity being greater than said threshold triggers a shape memory effect of at least one of the first and second material, e.g. of the first material.
Optionally, the first material may be one or more azobenzene groups in liquid crystalline polyurethane networks and the second material may be polyurethane without azobenzene.
For example, in case the first material and the second material have different expansion coefficients with regard to ultra-violet radiation, the first material and the second material may be configured to expand or contract in response to the element being exposed to a dedicated amount of ultra-violet radiation for a dedicated period of time. Thus, in the aforementioned case, the expansion or contraction of the first material and the second material may be triggered by a radiation flux of ultra-violet radiation being greater than a threshold for the radiation flux of ultra-violet radiation. For example, the first material and/or the second material may be one or more liquid crystal elastomers (LCE) with azobenzene. The first material and/or the second material may be an LCE film comprising azobenzene. In the aforementioned optional case, the ultra-violet radiation may be a 365 nm ultra-violet radiation for triggering the shape change of the first part of the element. The shape change of the first part of the element may be for example a bending or unbending. The first material and/or second material may be optionally one or more azobenzene groups in liquid crystalline polyurethane networks. Optionally, the first material may be one or more azobenzene groups in liquid crystalline polyurethane networks and the second material may be polyurethane without azobenzene.
For example, in case the first material and the second material have different expansion coefficients with regard to electric current or voltage, the first material and the second material may be configured to expand or contract in response to the element being exposed to a dedicated amount of electric current or voltage, respectively, for a dedicated period of time. Thus, in the aforementioned case, the expansion or contraction of the first material and the second material may be triggered by an electric current or voltage being greater than a threshold for the electric current or voltage, respectively. Optionally, the first material and/or second material may be one or more shape memory polymers filled with elements that heat up when a voltage is applied to the shape memory polymer. For example, the first material and/or second material may be one or more shape memory polymers with conductive fillers, such as at least one of carbon nanotubes, carbon nanofibers and carbon black. Such shape memory polymers allow for electro-activation of the shape memory effect. In the aforementioned case, the material(s) allow using electricity for internal resistive Joule heating to trigger a shape change in the shape memory polymers and, thus, change of the shape of the first part of the element. The aforementioned materials may be referred to as "conductive shape memory polymers" or "polymer nanocomposites". For example, the first material and/or second material maybe a shape memory polymer composite made of a carbon nanofiber (CNF) filled epoxidized soybean oil (ESBO) and bisphenol F diglycidyl ether (BFDGE) resin. Optionally, the composite may have a CNF volume fraction of 5.6% and an electrical conductivity of 0.4 S cm^-1. This allows an electrical stimulation of the shape memory effect. In the aforementioned case, the electric current and voltage for triggering the shape change of the first part of the element may optionally be 150 mA and 20 V, respectively. Exposing the element to the electric current or voltage allows for resistive heating of the element, which triggers the shape change of the first part of the element.
Optionally, the first shape of the first part is a folded shape, and the second shape of the first part is an unfolded shape. For example, the first material and second material may be arranged such that the shape of the first part of the element unfolds from a folded shape to an unfolded shape due to an expansion of the first material and second material caused by the exposure of the element to the one or more types of stimuli.
Optionally, the first material and second material are arranged such that the first part expands according to a scissor jack when the shape of the first part changes from the first shape to the second shape due to an expansion of the first material and second material caused by the exposure of the element to the one or more types of stimuli.
The first material and the second material may comprise at least one of one or more shape memory alloys, one or more shape memory polymers, and one or more phase change materials.
An example of a shape memory alloy is nitinol. Examples of shape memory polymers are elastic photopolymer, polylactide and polyurethane. Examples of phase change materials are ethanol in silicone matrix and methanol in silicone matrix.
Optionally, at least one of the first material and second material is adapted to expand or contract the more, the greater the one or more types of stimuli and vice versa. In other words, as soon as the one or more types of stimuli are greater than a threshold for triggering the expansion or contraction of the first and second material and, thus triggering the change of the shape of the first part of the element, the expansion or contraction of one or both of the first material and second material may be more the greater the one or more types of stimuli. This allows a gradually change from the first shape to the second shape. For example, in case the change from the first shape to the second shape comprises an extension of the first part in a direction, the greater the one or more types of stimuli the greater the extension in the direction may be.
Optionally, the first material and second material are adapted to reversibly expand or contract when the element is exposed to the one or more types of stimuli such that the expansion or contraction, respectively, exists while the element is exposed to the one or more types of stimuli, and the expansion or contraction, respectively, is reversed when the exposure of the element to the one or more types of stimuli is stopped.
For example, the first material and second material may be adapted to reversibly expand or contract when the element is exposed to ultra-violet radiation such that the expansion or contraction, respectively, exists while the element is exposed to the ultra-violet radiation, and the expansion or contraction, respectively, is reversed when the exposure of the element to the ultra-violet radiation is stopped. For example, the first material and second material may be adapted to reversibly expand or contract when the element is exposed to light having a light intensity greater than a respective threshold such that the expansion exists while the element is exposed to the light intensity being greater than the respective threshold, and the expansion or contraction, respectively, is reversed when the exposure of the element to the light intensity being greater than the respective threshold is stopped.
Optionally, the degree of expansion or contraction of the first material and second material may depend on the amount of the one or more types of stimuli, such as ultra-violet radiation or light. For example, when the first shape of the first part of the element is a folded shape and the second shape of the first part of the element is an unfolded shape, the degree of unfolding of the first part of the element from the folded shape to the unfolded shape may depend on the amount of the one or more types of stimuli, such as ultra-violet radiation or light, to which the element is exposed to. The greater the amount of the one or more types of stimuli, e.g. the greater the amount or radiant flux of the ultra-violet radiation or the greater the amount or light intensity of light, the more the first part may unfold from the folded shape to the unfolded shape.
In case the first material and second material comprise different expansion coefficients with regard to ultra-violet radiation, increasing the amount or radiant flux of the ultra-violet radiation may cause the first part of the element to unfold more from the folded to the unfolded shape. In case the first material and second material comprise different expansion coefficients with regard to light, increasing the amount or light intensity of the light may cause the first part of the element to unfold more from the folded to the unfolded shape. The unfolding may thus take gradually place. That is, this allows achieving different degrees of unfolding. Optionally, decreasing the amount or radiant flux of the ultra-violet radiation may cause the first part of the element to fold more from the unfolded to the folded shape. Optionally, decreasing the amount or light intensity of the light may cause the first part of the element to fold more from the unfolded to the folded shape. The folding may thus take gradually place. That is, this allows achieving different degrees of folding. This may be advantageous in case the element is a light guiding unit, such as a lampshade. Namely, different degrees of folding or unfolding of the light guiding unit may result in different light guiding characteristics of the light guiding unit.
The first part of the element may be generated by additive manufacturing.
Optionally the element is generated by additive manufacturing. For example, the first part and second part may be generated by additive manufacturing. The first part may be configured such that the different expansion coefficients of the first material and the second material cause tensions in the first part when the first part is generated by additive manufacturing using at least the first and second material. Thus, when the element is exposed to the one or more types of stimuli, the first and second materials expand or contract causing the shape of the first part of the element to change from the first shape to the second shape.
The element may be a heat sink, a light guiding unit or housing.
The light guiding unit may be or may comprise a reflector, e.g. in the form of a lampshade. The light guiding unit may be a lampshade configured to soften and/or directing light.
The element may be an element for a luminaire or an element for lighting means.
The luminaire may be an indoor or outdoor luminaire. For example, the luminaire may be a spot luminaire, a downlight luminaire etc. The lighting means may be LED lighting means comprising one or more LEDs. The lighting means may be a retrofit LED lighting means, such as a retrofit bulb comprising one or more LEDs as light source.
In order to achieve the element according to the first aspect of the present invention, some or all of the above-described optional features may be combined with each other.
According to a second aspect of the invention, a lighting system is provided. The lighting system comprises a light source, and an element according to the first aspect, as described above. The lighting system is configured to cause a change of the shape of the first part of the element from the first shape to the second shape by exposing the element to the one or more types of stimuli. Optionally, the light source is configured to cause a change of the shape of the first part of the element from the first shape to the second shape by exposing the element to the one or more types of stimuli.
That is, the lighting system, optionally the light source, is configured to expose the element to the one or more types of stimuli in order to cause the change of the shape of the first part of the element from the first shape to the second shape. The lighting system may be a luminaire or lighting means.
For example, when the light source emits light, the light source outputs heat. The element may be arranged in the lighting system such that it is exposed to the heat output by the light source. Thus, the first part of the element may be configured to change its shape from the first shape to the second shape due to the expansion or contraction of the first material and second material caused by the exposure of the element to the heat output by the light source. In the aforementioned case, the first material and second material have different expansion coefficients with regard to heat. In the aforementioned case, the element may be a heat sink arranged in the lighting system for guiding the heat output by the light source away from the light source, e.g. to outside the lighting system, in order to counter a temperature rise in the lighting system and, e.g. preventing the light source from overheating.
Optionally, the first material and second material may have different expansion coefficients with regard to light. Thus, the element may be arranged at the lighting system such that it is exposed to light emitted by the light source. Therefore, the first part of the element may be configured to change its shape from the first shape to the second shape due to the expansion or contraction of the first material and second material caused by the exposure of the element to the light output by the light source. In the aforementioned case, the element may be a light guiding unit arranged at the lighting system for guiding light emitted by the light source to outside the lighting system in order to achieve a desired light emitting characteristic, e.g. main direction of light emission, of the lighting system.
For example, the light source and/or an optional additional ultra-violet radiation source may radiate ultra-violet radiation. The element may be arranged in the lighting system such that it is exposed to the radiated ultra-violet radiation. Thus, the first part of the element may be configured to change its shape from the first shape to the second shape due to the expansion or contraction of the first material and second material caused by the exposure of the element to the radiated ultra-violet radiation. In the aforementioned case, the first material and second material have different expansion coefficients with regard to ultra-violet radiation. In the aforementioned case, the element may be a light guiding unit arranged at the lighting system for guiding light emitted by the light source to outside the lighting system in order to achieve a desired light emitting characteristic, e.g. main direction of light emission, of the lighting system.
For example, the lighting system may comprise an electric current and/or voltage source. The electric current and/or voltage source may optionally comprise at least one converter, e.g. an actively switched converter. The electric current and/or voltage source may be configured to electrically supply the light source by providing an electric current and/or voltage to the light source. Thus, light emission of the light source may be controlled by controlling operation of the electric current and/or voltage source. The element may be arranged in the lighting system such that it is exposed to an electric current and/or voltage provided by the electric current and/or voltage source. Thus, the first part of the element may be configured to change its shape from the first shape to the second shape due to the expansion or contraction of the first material and second material caused by the exposure of the element to the provided electric current and/or voltage. In the aforementioned case, the first material and second material have different expansion coefficients with regard to electric current and/or voltage. In the aforementioned case, the element may be a heat sink arranged in the lighting system or a light guiding unit arranged at the lighting system for guiding light emitted by the light source to outside the lighting system in order to achieve a desired light emitting characteristic, e.g. main direction of light emission, of the lighting system.
Optionally, the lighting system comprises a ultra-violet radiation source in addition to the light source for causing the change of the shape of the first part of the element with heat and/or ultra-violet radiation. The light source may be configured to radiate a spectrum comprising ultra-violet radiation in an amount greater than a threshold for causing the change of the shape of the first part of the element with ultra-violet radiation.
The ultra-violet radiation source may be configured to be controlled to radiate the ultra-violet radiation for causing the change of the shape of the first part of the element during an initial start-up phase or commissioning phase of the lighting system. For example, the initial start-up phase may be an operation mode of the lighting system that is performed by the lighting system at an initial placing into operation of the lighting system. The light source may be configured to be controlled to radiate the spectrum comprising ultra-violet radiation in an amount greater than a threshold for causing the change of the shape of the first part of the element during an initial start-up phase or commissioning phase of the lighting system.
The light source may be configured to be controlled to emit light in an amount or with an light intensity greater than a threshold for causing the change of the shape of the first part of the element during an initial start-up phase or commissioning phase of the lighting system.
Optionally, the lighting system comprises a heating element in addition to the light source for causing the change of the shape of the first part of the element with heat.
That is, the lighting system may comprise a heating element for providing sufficient heat for causing the expansion or contraction of the first material and second material of the first part of the element and, thus, the change of the shape of the first part of the element. Optionally, the heating element may be controlled to output heat for causing the change of the shape of the first part of the element during an initial start-up phase or commissioning phase of the lighting system.
Optionally, the lighting system comprises one or more electrical connectors for electrically connecting the first part of the element and causing the change of the shape of the first part of the element with electric current and/or voltage.
The one or more electrical connectors may be coupled to an electric current and/or voltage source. Thus, when the first part of the electrically element is connected to the electrical connectors, the electric current and/or voltage source may provide an electric current and/or voltage for causing the change of the shape of the first part of the element. The above description of an electric current and/or voltage source is correspondingly valid for the aforementioned electric current and/or voltage source. Optionally, the electric current and/or voltage source may be controlled to provide the electric current and/or voltage to the element for causing the change of the shape of the first part of the element during an initial start-up phase or commissioning phase of the lighting system.
Optionally, the light source is configured to be controlled to radiate with a radiant flux greater than a threshold for triggering the change of the shape of the first part of the element with at least one of heat, light and ultra-violet radiation. The light source may be configured to be controlled to radiate an amount of light and/or ultra-violet radiation greater than a respective threshold for causing the change of the shape of the first part of the element with light and/or ultra-violet radiation.
In other words, the light source may be configured to be controlled to emit with a light intensity greater than a threshold for triggering the change of the shape of the first part of the element with at least one of heat, light and ultra-violet radiation.
The lighting system may comprise or may be connectable to a control unit for controlling operation of the lighting system. The control unit may be configured to control the light source. The control unit may be configured to control components of the lighting system, such as the optional electric current and/or voltage source, the optional ultra-violet radiation source, and the optional heating element. The control unit may comprise at least one of a controller, a microcontroller, a processor, a microprocessor, an application specific integrated circuit (ASIC) and a field programmable gate array (FPGA). In addition or alternatively, the control unit may comprise any other control means known in the art.
The lighting system may be a luminaire or lighting means.
The luminaire may be an indoor or outdoor luminaire. For example, the luminaire may be a spot luminaire, a downlight luminaire etc. The lighting means may be LED lighting means comprising one or more LEDs. The lighting means may be a retrofit LED lighting means, such as a retrofit bulb comprising one or more LEDs as light source.
The above description with regard to the element according to the first aspect of the present invention is correspondingly valid for the lighting system according to the second aspect. The description with regard to the lighting system according to the second aspect is correspondingly valid for the element according to the first aspect.
The lighting system according to the second aspect achieves the same advantages as the element according to the first aspect.
In order to achieve the lighting system according to the second aspect of the present invention, some or all of the above-described optional features may be combined with each other.
All steps which are performed by the various entities described in the present application as well as the functionalities described to be performed by the various entities are intended to mean that the respective entity is adapted to or configured to perform the respective steps and functionalities.
In the following, the invention is described exemplarily with reference to the enclosed figures (FIGs.), in which

FIG. 1: schematically shows a first shape and second shape of an example of an element according to an embodiment of the invention for a lighting system;
FIG. 2: schematically shows a first shape and second shape of an example of an element according to an embodiment of the invention for a lighting system;
FIG. 3: schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention;
FIG. 4: schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention; and
FIG. 5: schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention.

In the figures (FIGs.), corresponding elements have the same reference signs. The proportions and dimensions of the components shown in the FIGs. do not represent the element for a lighting system or the lighting system to scale, but are merely chosen to describe the structure and function of the element for a lighting system or the lighting system, respectively.
FIG. 1 schematically shows a first shape and second shape of an example of an element according to an embodiment of the invention for a lighting system. The element 1 of FIG. 1 is an example of the element according to the first aspect of the present invention. Thus, the description of the element of the first aspect is correspondingly valid for the element 1 of FIG. 1.
The element 1 of FIG. 1 is an element for a lighting system. The lighting system may be a luminaire or lighting means. The element 1 comprises a first part 2 and a second part 3. The first part 2 is made of at least a first material and a second material. The first material and the second material have different expansion coefficients with regard to one or more types of stimuli. The first material and second material are arranged such that a shape of the first part 2 changes from a first shape (shown on the left side of FIG. 1) to a second shape (shown on the right side of FIG. 1) due to an expansion or contraction of the first material and second material caused by an exposure of the element to the one or more types of stimuli. The exposure of the element to the one or more types of stimuli is indicated in FIG. 1 by the arrow. As shown in FIG. 1, the second part does not structurally change when the element is exposed to the one or more types of stimuli.
The one or more types of stimuli may comprise at least one of heat, light, ultra-violet radiation, electric current and voltage.
According to the example of FIG. 1, the first material and second material of the first part 2 of the element 1 are arranged such that the first part 2 expands according to a scissor jack (as indicated on the right side of FIG. 1) when the shape of the first part 2 changes from the first shape to the second shape due to an expansion of the first material and second material caused by the exposure of the element to the one or more types of stimuli. Thus, according to the example of FIG. 1, the first shape of the first part 2 of the element 1 is a folded shape, and the second shape of the first part 2 of the element 1 is an unfolded shape.
The kind of shape change shown in FIG. 1 is only by way of example and may be differently. A different example of how the shape of the first part 2 of the element 1 may change due to an expansion of the first material and second material caused by the exposure of the element 1 to the one or more types of stimuli is shown in FIG. 2. The shape of the first part 2 of the element 1 may change optionally due to a contraction of the first material and second material caused by the exposure of the element 1 to the one or more types of stimuli.
FIG. 2 schematically shows a first shape and second shape of an example of an element according to an embodiment of the invention for a lighting system. The element 1 of FIG. 2 corresponds to the element 1 of Figure 1, wherein the kind of material of the first material and/or second material of the first part 2 of the element 1 and/or the arrangement of the first and second material is different. As a result, the type of change of the shape of the first part 2 of the element 1 of FIG. 2 is different with regard to the element 1 of FIG. 1. The description with regard to FIG. 1 is correspondingly valid for the element 1 of FIG. 2 and in the following mainly the difference of the element 1 of FIG. 2 with regard to the element 1 of Figure 1 is described.
As shown in FIG. 2, the shape of the first part 2 of the element 1 changes due to the expansion of the first material and second material caused by the one or more different types of stimuli in that the first part 2 is bended. Optionally, the shape of the first part 2 of the element 1 may change due to a contraction of the first material and second material caused by the one or more types of stimuli. That is, the first shape of the first part 2 of the element 1 of FIG. 2 is a non-bended straight shape (shown on the left side of FIG. 2), whereas the second shape of the first part 2 of the element 1 of FIG. 2 is a bended shape (shown on the right side of FIG. 2). The present invention is not limited to the shape changes shown in the examples of FIGs. 1 and 2 and, thus, the first and second material may be selected and arranged such that different shape changes of the first part 2 of the element 1 may be achieved by exposing the element 1 to the one or more respective types of stimuli.
FIG. 3 schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention. The lighting system 6 of FIG. 3 is an example of a lighting system according to the second aspect of the present invention. Thus, the description of the lighting system according to the second aspect is correspondingly valid for the lighting system 6 of FIG. 3.
As shown in FIG. 3, the lighting system 6 comprises a light source 4, and an element 1 according to an example of this invention. The element 1 of the lighting system 6 of FIG. 3 is the element 1 of FIG. 1. Therefore, the description with regard to FIG. 1 is valid for the element 1 of the lighting system 6 of FIG. 3.
The lighting system 6 is configured to cause a change of the shape of the first part 2 of the element 1 from the first shape to the second shape by exposing the element 1 to the one or more types of stimuli. Optionally, the light source 4 is configured to cause a change of the shape of the first part 2 of the element 1 from the first shape to the second shape by exposing the element to the one or more types of stimuli. On the left side of FIG. 3 the first shape of the element 1 of the lighting system 6 and on the right side of FIG. 3 the second shape of the element 1 of the lighting system 6 is shown.
The light source 4 may comprise one or more LEDs. The present disclosure is not limited to a specific type of LEDs.
As shown in FIG. 3, the light source 4 and the element 1 may be arranged on opposite sides of a printed circuit board 5 (PCB). The printed circuit board 5 may be used for providing an electrical supply from an electrical energy supply unit, such as an electric current and/or voltage source, to the light source 4. The electrical energy supply unit, such as the electric current and/or voltage source, may be arranged on the PCB 5 (not shown in FIG. 3). A control unit of the lighting system 6 may be arranged on the PCB 5 for controlling operation of the lighting system 6 (not shown in FIG. 3), e.g. for controlling light emission by the light source 4. For example, the control unit may be configured to control light emission of the light source 4 by controlling an electrical energy supply to the light source 4, e.g. by controlling the electrical energy supply unit. The second part 3 of the element 1 may be configured to be mounted to the PCB 5 for installing the element 1 in the lighting system 6.
The element 1 of Figure 3 may be a heat sink for absorbing heat output by the light source 4 and optionally other elements arranged on the PCB 5 and guiding the heat away from the light source 4. As shown in FIG. 3, the size of the first shape of the first part 2 of the element 1 (i.e. the folded shape), shown on the left side of FIG. 3, is smaller than the size of the second shape of the first part 2 of the element 1 (i.e. the unfolded shape), shown on the right side of FIG. 3. The first shape is therefore better suited for transport, storage and installing the element 1 in the lighting system 6 (e.g. via an opening of the lighting system 6) compared to the second shape. Assuming that the element 1 is a heat sink, the second shape is better suited for the function of the element 1, i.e. function of being a heat sink, compared to the first shape. The unfolded shape of the first part 2 of the element 1, where the first part 2 of the element 1 extends in a direction away from the light source 4 allows guiding heat output by the light source 4 further away from the light source 4 compared to the first part 2 having the first shape.
Optionally, the heat output by the light source 4, when the light source 4 emits light (as indicated on the right side of FIG. 3 by dashed lines) may cause the expansion of the first material and second material of the first part 2 of the element 1 and, thus, the change of the shape of the first part 2 of the element 1 from the first shape to the second shape. The lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 to emit light with a light intensity greater than a threshold 1 in order to achieve an amount of heat greater than a threshold for changing the shape of the first part 2 of the element 1. Optionally, the lighting system 6, e.g. the control unit of the lighting system 6, may perform this control during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6. Optionally, the lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 to emit light having the aforementioned light intensity only for causing the change of the shape of the first part 2 of the element 1. That is, during a normal operation mode of the lighting system 6 the lighting system 6 may control the light source 4 to emit light with a light intensity that is smaller than the aforementioned threshold. As a result, during the normal operation less heat is output by the light source 4 and, thus, there is less stress on the components of the lighting system 6.
In the aforementioned case, the lighting system 1 may comprise a heating element (not shown in FIG. 3) for causing the change of the shape of the first part 2 of the element 1 with heat. The lighting system 6, e.g. a control unit of the lighting system 6, may control the heating element to output heat during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6. In the aforementioned case, the first material and second material of the first part 2 of the element 1 have different expansion coefficients with regard to heat.
Optionally, the lighting system 1 comprises one or more electrical connectors for electrically connecting the first part 2 of the element 1 and causing the change of the shape of the first part 2 of the element 1 with electric current and/or voltage. The one or more electrical connectors may be arranged in the lighting system 6 such that the first part 2 of the element 1 is electrically connected to the one or more electrical connectors when the element 1 is installed via the second part 3 of the element 1 in the lighting system 6. For example, the one or more electrical connectors maybe arranged on the PCB 5 such that the first part 2 of the element 1 is electrically connected to the one or more electrical connectors when the second part 3 of the element 1 is mounted to the PCB 5.
The one or more electrical connectors may be coupled to an electric current and/or voltage source. The electric current and/or voltage source may be an electrical energy supply unit of the lighting system 6 for electrically supplying the light source 4. In addition or alternatively, the electric current and/or voltage source may be an additional electric current and/or voltage source in addition to the electrical energy supply unit of the lighting system 6. The lighting system 6, e.g. a control unit of the lighting system 6, may control the electric current and/or voltage source to output an electric current and/or voltage via the one or more electrical connectors to the first part 2 of the element 1 for changing the shape of the first part 2 of the element 1 with the electric current and/or voltage. Optionally, the lighting system 6, e.g. the control unit of the lighting system 6, may perform this control during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6. In the aforementioned case, the first material and second material of the first part 2 of the element 1 have different expansion coefficients with regard to electric current and/or voltage.
Optionally, the lighting system 6 may be lighting means. In this case the components of the lighting system 6, such as the light source 4 and the PCB 5, may be arrange inside an enclosure of the lighting means. The light source 4 may comprise for example one or more LEDs. For example, the lighting means may be retrofit LED lighting means. The lighting means may be used as a light source in a luminaire. The element 1 being a heat sink is configured to be arranged inside the enclosure of the lighting means. The first shape of the first part 2 of the element 1 may be designed to be as compact as possible. This is advantageous with regard to transport and storage, because the element 1 with the first part 2 having the first shape will not consume a lot of space. In addition, this may be advantageous with regard to installing the element 1 inside the enclosure of the lighting means, i.e. when assembling the lighting means. Namely, the element 1 may easily be input through an opening of the enclosure inside the enclosure due to its compact size. The second shape of the first part 2 of the element 1 may be adapted to the shape of the enclosure of the lighting means and to be as large as possible with regard to the free space inside the enclosure. This is advantageous with regard to the function of a heat sink, because the larger the heat sink the more heat it may absorb.
Optionally, the lighting system 6 may be a luminaire. In this case, the components of the lighting system 6, such as the light source 4 and the PCB 5, may be arranged inside a housing of the luminaire (i.e. inside the luminaire housing). The element 1 being a heat sink is configured to be arranged inside the housing of the luminaire. The first shape of the first part 2 of the element 1 may be designed to be as compact as possible. This has the above-mentioned advantages. The second shape of the first part 2 of the element 1 may be adapted to the shape of the housing of the luminaire and to be as large as possible with regard to the free space inside the housing. This is advantageous with regard to the function of a heat sink, because the larger the heat sink the more heat it may absorb.
The element 1 with the first shape and second shape shown in FIG. 3 may be used for a different function, for example as a light guiding unit. This is exemplarily described with regard to FIG. 4.
FIG. 4 schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention. The lighting system 6 of FIG. 4 corresponds to the lighting system 6 of FIG. 3, where the element 1 is differently used. Thus, the description with regard to FIG. 3 is correspondingly valid for the lighting system 6 of FIG. 4 and in the following mainly the difference of the lighting system 6 of FIG. 4 with regard to the one of FIG. 3 is described.
As shown in FIG. 4, the element 1 may be used as a light guiding unit for the lighting system 6. In this case, the element 1 is configured to be arranged at a light emitting location, e.g. light emitting surface of a housing or enclosure, of the lighting system 6, through which the light emitted by the light source 4 travels in order to be emitted to the outside of the lighting system 6. Thus, the second part 3 of the element 1 may be configured to be installed or mounted to a light emitting location, such as light emitting surface of a housing or enclosure, of the lighting system 6. Since the element 1 is configured to be arranged at the light emitting location of the lighting system, the light emitted by the light source 4 may impinge on the element 1 and, thus, may be used to trigger the change of the shape of the first part 2 of the element 1 from the first shape to the second shape.
Optionally, the first material and second material of the first part 2 of the element 1 have different expansion coefficients with regard to light emitted by the light source 4.
The lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 to emit light with a light intensity greater than a threshold 1 for changing the shape of the first part 2 of the element 1 with the light. Optionally, the lighting system 6, e.g. the control unit of the lighting system 6, may perform this control during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6. Optionally, the lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 to emit light having the aforementioned light intensity only for causing the change of the shape of the first part 2 of the element 1. That is, during a normal operation mode of the lighting system 6 the lighting system 6 may control the light source 4 to emit light with a light intensity that is smaller than the aforementioned threshold.
Optionally, the first material and second material of the first part 2 of the element 1 have different expansion coefficients with regard to ultra-violet radiation.
Optionally, the light source 4 is configured to radiate a spectrum comprising ultra-violet radiation in an amount greater than a threshold for causing the change of the shape of the first part 2 of the element 1 with ultra-violet radiation. In addition or alternatively, the lighting system 6 may comprise a ultra-violet radiation source in addition to the light source 4 (not shown in FIG. 4) for causing the change of the shape of the first part 2 of the element 1 with ultra-violet radiation.
The lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 to radiate the spectrum comprising ultra-violet radiation in an amount greater than a threshold 1 for changing the shape of the first part 2 of the element 1. Optionally, the lighting system 6, e.g. the control unit of the lighting system 6, may perform this control during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6. The lighting system 6, e.g. a control unit of the lighting system 6, may control the optional ultra-violet radiation source to radiate ultra-violet radiation for changing the shape of the first part 2 of the element 1. Optionally, the lighting system 6, e.g. the control unit of the lighting system 6, may perform this control during a time during which the change of the shape of the first part 2 of the element 1 from the first shape to the second shape is to be performed. This time may be an initial start-up phase or commissioning phase of the lighting system 6.
Optionally, the lighting system 6, e.g. a control unit of the lighting system 6, may control the light source 4 and the optional ultra-violet radiation source to radiate ultra-violet radiation only for causing the change of the shape of the first part 2 of the element 1. That is, during a normal operation mode of the lighting system 6 the lighting system 6 may control the light source 4 to emit light desired for providing a lighting to an area, such as an indoor or outdoor area.
The first shape of the element 1 being a light guiding unit may be designed to be as compact as possible. This has the above-mentioned advantages. The second shape of the first part 2 of the element 1 being a light guiding unit 1 may be designed to achieve a light guiding function. For example, the element 1 having the second shape (being an unfolded shape) may have the form of a lampshade for softening and/or directing light emitted by the light source 4.
The first shape and second shape of the first part 2 of the element 1 shown in FIGs. 3 and 4 is only by way of example and may be differently. FIG. 5 shows an example, where the element 1 is also used as a light guiding element, but the first part 2 of the element 1 has a different first and second shape.
FIG. 5 schematically shows a first state and second state of an example of a lighting system according to an embodiment of the invention. The lighting system 6 of FIG. 5 corresponds to the lighting system 6 of FIG. 4, where the first part 2 of the element 1 has a different first shape and second shape. Thus, the description with regard to FIGs. 3 and 4 is correspondingly valid for the lighting system 6 of FIG. 5 and in the following mainly the difference of the lighting system 6 of FIG. 5 with regard to the one of FIG. 4 is described.
As shown in FIG. 5, the element 1 of the lighting system 6 of FIG. 5 is the element 1 of FIG. 2. Thus, the description with regard to FIG. 2 is valid for the element 1 of the lighting system 6 of FIG. 5. Thus, the shape of the first part 2 of the element 1 changes due to the expansion of the first material and second material e.g. caused by ultra-violet radiation, in that the first part 2 is bended. That is, the first shape of the first part 2 of the element 1 of FIG. 5 is a non-bended straight shape (shown on the left side of FIG. 5), whereas the second shape of the first part 2 of the element 1 of FIG. 5 is a bended shape (shown on the right side of FIG. 5).
In the claims as well as in the description the word "comprising" does not exclude other elements or steps and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in the mutual different dependent claims does not indicate that a combination of these measures cannot be used in an advantageous implementation.

Claims

An element (1) for a lighting system comprising a first part (2) and a second part (3), wherein
- the first part (2) is made of at least a first material and a second material, the first material and the second material having different expansion coefficients with regard to one or more types of stimuli;

- the first material and second material are arranged such that a shape of the first part (2) changes from a first shape to a second shape due to an expansion or contraction of the first material and second material caused by an exposure of the element (1) to the one or more types of stimuli; and

- the second part (3) maintains its shape when the element (1) is exposed to the one or more types of stimuli.
The element (1) according to claim 1, wherein
- the one or more types of stimuli comprise at least one of heat, light, ultra-violet radiation, electric current and voltage.
The element (1) according to any one of the previous claims, wherein
- the first shape of the first part (2) is a folded shape, and

- the second shape of the first part (2) is an unfolded shape.
The element (1) according to any one of the previous claims, wherein
- the first material and second material are arranged such that the first part (2) expands according to a scissor jack when the shape of the first part (2) changes from the first shape to the second shape due to an expansion of the first material and second material caused by the exposure of the element (1) to the one or more types of stimuli.
The element (1) according to any one of the previous claims, wherein
- the first material and the second material comprise at least one of one or more shape memory alloys, one or more shape memory polymers, and one or more phase change materials.
The element (1) according to any one of the previous claims, wherein
- the first material and second material are adapted to reversibly expand or contract when the element (1) is exposed to the one or more types of stimuli such that
- the expansion or contraction, respectively, exists while the element (1) is exposed to the one or more types of stimuli, and

- the expansion or contraction, respectively, is reversed when the exposure of the element (1) to the one or more types of stimuli is stopped.
The element (1) according to any one of the previous claims, wherein
- the first part (2) of the element (1) is generated by additive manufacturing.
The element (1) according to any one of the previous claims, wherein
- the element (1) is a heat sink, a light guiding unit or housing.
The element (1) according to any one of the previous claims, wherein
- the element (1) is an element for a luminaire or lighting means.
A lighting system (6) comprising,
- a light source (4), and

- an element (1) according to any of the previous claims, wherein

- the lighting system (6), optionally the light source (4), is configured to cause a change of the shape of the first part (2) of the element (1) from the first shape to the second shape by exposing the element (1) to the one or more types of stimuli.
The lighting system (6) according to claim 10, wherein
- the lighting system (1) comprises an ultra-violet radiation source in addition to the light source (4) for causing the change of the shape of the first part (2) of the element (1) with heat and/or ultra-violet radiation; and/or

- the light source (1) is configured to radiate a spectrum comprising ultra-violet radiation in an amount greater than a threshold for causing the change of the shape of the first part (2) of the element (1) with ultra-violet radiation.
The lighting system (6) according to claim 10 or 11, wherein
- the lighting system (6) comprises a heating element in addition to the light source (4) for causing the change of the shape of the first part (2) of the element (1) with heat.
The lighting system (6) according to any one of claims 10 to 12, wherein
- the lighting system (6) comprises one or more electrical connectors for electrically connecting the first part (2) of the element (1) and causing the change of the shape of the first part (2) of the element (1) with electric current and/or voltage.
The lighting system (6) according to any one of claims 10 to 13, wherein
- the light source (4) is configured to be controlled to radiate with a radiant flux greater than a threshold for triggering the change of the shape of the first part (2) of the element (1) with at least one of heat, light and ultra-violet radiation; and/or

- the light source (4) is configured to be controlled to radiate an amount of light and/or ultra-violet radiation greater than a respective threshold for causing the change of the shape of the first part (2) of the element (1) with light and/or ultra-violet radiation.
The lighting system (6) according to any one of claims 10 to 14, wherein
- the lighting system (6) is a luminaire or lighting means.