Patent Description:
An LED strip is a component with a plurality of light-emitting diodes arranged on a surface of an elongated carrier. The elongated carrier is typically a printed circuit board, which may be flexible, and the plurality of light-emitting diodes is typically arranged in the form of a linear array. The plurality of light-emitting diodes, and optionally also the carrier, may be encapsulated with a light-transmissive encapsulant.

Lighting devices comprising LED strips are widely available and commonly used for consumer as well as professional applications in indoor and outdoor lighting.

Depending on the application, the lighting device should have a desired light distribution or light output, which is usually different from one application to the other. A lighting device comprising an LED strip is typically arranged to provide a light distribution or light output that is designed to suit a specific application. Prior art lighting devices are disclosed in <CIT> and <CIT>.

A lighting device comprising an LED strip that is arranged to be attached to a mounting surface of an object typically has an adhesive backing. The inventors have realized that a construction with an adhesive backing has a drawback. For certain applications of the lighting device the illumination output can only be obtained when the lighting device with an adhesive backing is mounted on the object in plain sight. When in such an application the lighting device with an adhesive backing would be attached to a different mounting surface of the object so that it is no longer in plain sight, the lighting device will not be able to provide the desired illumination output.

In view of the above, there is a need to have a lighting device comprising an LED strip that can be attached to a mounting surface of an object in an unobtrusive way without compromising the desired illumination output. It is an object of the invention to provide such an improved lighting device. The invention is defined by a lighting device according the independent claim <NUM>.

According to a first aspect of the invention, the lighting device comprises an LED strip, and the LED strip comprises (i) an elongated carrier with an upper surface having a first upper surface portion, (ii) a plurality of light-emitting diodes arranged on the first upper surface portion, and (iii) an attachment component for attaching the lighting device to the mounting surface of the object. The attachment component has an adhesive surface that faces in at least one of a first direction and a second direction, wherein the first direction is parallel to the normal of the upper surface of the elongated carrier, and wherein the second direction is perpendicular to the normal of the upper surface of the elongated carrier and perpendicular to the direction of elongation of the elongated carrier.

The LED strip has a LED strip length (L), a LED strip width (W) and a LED strip height (H).

The LED strip length (L) may be at least <NUM> times the LED strip width (W), such as at least <NUM> times the LED strip width (W), or at least <NUM> times the LED strip width (W).

The LED strip length (L) may be at least <NUM> times the LED strip height (H), such as at least <NUM> times the LED strip height (H), or at least <NUM> times the LED strip height (H).

The LED strip length (L) may be at least <NUM> meter, such as at least <NUM> meter, or at least <NUM> meters.

The upper surface of the elongated carrier may be light-reflective, for example with a reflectivity of at least <NUM> %, such as at least <NUM> %, or at least <NUM> %.

The elongated carrier may have a thickness in the range of <NUM> millimeter to <NUM> millimeters, such as in the range of <NUM> millimeter to <NUM> millimeters, or in the range of <NUM> millimeter to <NUM> millimeter.

The elongated carrier may be rigid or flexible.

The elongated carrier may comprise a metal, such as aluminum or copper. Such an elongated carrier has good thermal management properties. Additionally, or alternatively, the elongated carrier may comprise a polymer, such as poly(methyl methacrylate) (PMMA), polycarbonate (PC), polyethylene (PE) or polyethylene terephthalate (PET).

The plurality of light-emitting diodes may consist of N light-emitting diodes, wherein N is at least <NUM>, such as at least <NUM>, at least <NUM>, at least <NUM> or at least <NUM>.

The plurality of light-emitting diodes may be arranged over the full length of the LED strip. They may additionally be equally distributed over the full length of the LED strip.

The plurality of light-emitting diodes may be arranged in a linear array of n × m light-emitting diodes, wherein n is <NUM>.

Each light-emitting diode may be a phosphor-converted light-emitting diode or a direct-emitting light-emitting diode.

Each light-emitting diode may be arranged to emit white light or colored light. The emitted white light may have a correlated color temperature in the range of <NUM> Kelvin to <NUM>, such as in the range of <NUM> Kelvin to <NUM>, or in the range of <NUM> Kelvin to <NUM>. The emitted white light may have a color rendering index of at least <NUM>, such as at least <NUM>, or at least <NUM>.

The plurality of light-emitting diodes may have a first subset of light-emitting diodes and a second subset of light-emitting diodes, wherein each light-emitting diode of the first subset is arranged to emit light of a first correlated color temperature and each light-emitting diode of the second subset is arranged to emit light of a second correlated color temperature, the first correlated color being lower than the second correlated color temperature. The lighting device may comprise a controller for individually controlling the luminous flux of each of the first and second subsets of light-emitting diodes.

The plurality of light-emitting diodes may have a first subset of light-emitting diodes, a second subset of light-emitting diodes and a third subset of light-emitting diodes, wherein each light-emitting diode of the first subset is arranged to emit light of a first color, each light-emitting diode of the second subset is arranged to emit light of a second color and each light-emitting diode of the third subset is arranged to emit light of a third color, and wherein the first color, the second color and the third color are three different colors. For example, the first color is red, the second color is green, and the third color is blue. The lighting device may comprise a controller for individually controlling the luminous flux of each of the first, second and third subsets of light-emitting diodes.

The attachment component may have a linear shape.

The adhesive surface of the attachment component may be covered with a release liner.

The upper surface of the elongated carrier has a second upper surface portion located next to the first upper surface portion in the direction of elongation of the elongated carrier, wherein the attachment component is provided on the second upper surface portion. The attachment component may cover at least <NUM> % of the second upper surface portion, such at least <NUM> % or at least <NUM> %. The attachment component may also cover substantially all of the second upper surface portion.

The plurality of light-emitting diodes are encapsulated with a light-transmissive encapsulant. The light-transmissive encapsulant may be a continuous encapsulant or it may have discrete encapsulant regions. The light-transmissive encapsulant may also encapsulate at least a part of the upper surface of the elongated carrier.

The light-transmissive encapsulant may comprise a polymer, such as a silicone. Such a light-transmissive encapsulant has good optical properties.

The attachment component has a first attachment component part with a first adhesive surface portion facing the first direction, the first adhesive surface portion being located at a first height from the upper surface in the first direction, wherein the light-transmissive encapsulant has a side surface parallel to the first direction and facing the second upper surface portion, wherein the side surface has a side surface dimension in the first direction, and wherein the side surface dimension is larger than the first height. In this way, the light transmissive encapsulant extends above the first attachment component (as seen in the first direction) and the side surface of the encapsulant may be used for aligning the lighting device when attaching it to the mounting surface of the object.

The attachment component may have a second attachment component part provided on the side surface of the light-transmissive encapsulant, the second attachment component part having a second adhesive surface portion facing the second direction.

The light-transmissive encapsulant may be arranged to provide an optical effect chosen from the group consisting of refraction, diffraction, reflection, diffusion and conversion.

Refraction of light refers to the change in direction of a light ray passing from one medium to another or from a gradual change in the medium. Prisms and lenses may be used to redirect light by means of refraction.

Diffraction of light refers to various phenomena that occur when a light ray encounters an obstacle or a slit. It may be defined as the bending of light rays around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle or aperture, wherein the diffracting object or aperture effectively becomes a secondary source of the propagating light ray.

Reflection of lights refers to the change in direction of a light ray at an interface between two different media so that the light ray returns into the medium from which it originated. For specular reflection, the angle at which the light ray is incident on the surface equals the angle at which it is reflected. Specular reflection may be achieved by means of a mirror. For diffuse reflection, a light ray that is incident on a surface is scattered at many angles rather than at just one angle as in the case of specular reflection.

Diffusion of light refers to a situation wherein a light ray travels through a material without being absorbed, but rather undergoes repeated scattering events which change the direction of its path.

Conversion of light refers to a change in wavelength of a light ray, such as by means of photoluminescence, wherein light is emitted from any form of matter after absorption of electromagnetic radiation. Conversion of light by means of photoluminescence may be achieved by using a phosphor.

The elongated carrier may have an F-profile with a first profile part and a second profile part oriented parallel to each other and perpendicular to a third profile part, the first profile part and the second profile part being separated from each other by a non-zero separation distance, wherein the first upper surface portion is located between the first profile part and the second profile part.

The non-zero separation distance between the first and second profile parts may be substantially constant over the length of the LED strip.

The lighting device may further comprise a cover over the first upper surface portion, the cover closing the separation distance between the first profile part and the second profile part.

The cover may be arranged to provide an optical effect chosen from the group consisting of refraction, diffraction, reflection, diffusion and conversion.

The plurality of light-emitting diodes may be encapsulated with a light-transmissive encapsulant, wherein the light-transmissive encapsulant has a side surface parallel to the first direction, and wherein the attachment component is provided on the side surface such that the adhesive surface faces the second direction.

The lighting device may further comprise an electrical component, such as a sensor, a driver for providing power to the light-emitting diodes and/or a controller for controlling the light output of the light-emitting diodes.

The lighting device according to the invention may be attached to a mounting surface of an object, wherein the object may be part of a constructional element or a building material.

The invention as claimed refers to the embodiments shown in <FIG>, <FIG>, <FIG>.

<FIG> shows a top view of an elongated carrier <NUM> having an upper surface with a first upper surface portion <NUM> and a second upper surface portion <NUM>. The first upper surface portion <NUM> is located next to the second upper surface portion <NUM> in the direction of elongation <NUM> of the elongated carrier <NUM>. Also indicated in <FIG> is direction <NUM>, which is perpendicular to the normal of the upper surface and to the direction of elongation <NUM> of the elongated carrier <NUM>.

<FIG> shows a lighting device <NUM> that comprises the elongated carrier <NUM> of <FIG>. The lighting device <NUM> is shown in a side view (upper portion of <FIG>) and a top view (lower portion of <FIG>).

The elongated carrier <NUM> has an upper surface <NUM> on which a plurality of light-emitting diodes <NUM> is arranged. In particular, the light-emitting diodes <NUM> are arranged on the first upper surface portion <NUM> of the upper surface <NUM>.

Also arranged on the upper surface <NUM> is an attachment component <NUM>. In particular, the attachment component <NUM> is arranged on the second upper surface portion <NUM> of the upper surface <NUM>.

The attachment component <NUM> has an adhesive surface <NUM> that faces in direction <NUM>. The direction <NUM> is parallel to the normal of the upper surface <NUM>. The directions <NUM> and <NUM> will hereinafter be referred to as the first direction <NUM> and the second direction <NUM>, respectively.

In the lighting device <NUM> of <FIG>, the light-emitting diodes <NUM> are arranged in a linear array, and the attachment component <NUM> has a linear shape. Alternatively, the arrangement of light-emitting diodes may have any configuration, and the attachment component may have any shape.

<FIG> shows several lighting devices <NUM> in a cross-sectional view.

In the lighting devices <NUM> shown in <FIG>, the adhesive surface <NUM> is covered with a release liner <NUM>.

In the lighting devices <NUM> shown in <FIG>, the light-emitting diodes <NUM> are encapsulated with a light-transmissive encapsulant <NUM>. The light-transmissive encapsulant <NUM> comprises a diffusive material. In other words, the light-transmissive encapsulant <NUM> is arranged to provide the optical effect of diffraction. Other materials may alternatively be used for the light-transmissive encapsulant, such as a refractive material, a diffractive material, a reflective material or a converting material, so that the light-transmissive encapsulant is arranged to provide the optical effect of refraction, diffraction, reflection or conversion, respectively.

In the lighting device <NUM> of <FIG>, the light-transmissive encapsulant <NUM> and the attachment component <NUM> have substantially the same height.

In the lighting device <NUM> of <FIG>, the first adhesive surface portion <NUM> is located at a first height h from the upper surface <NUM> in the first direction <NUM>. The light-transmissive encapsulant <NUM> has a side surface <NUM> parallel to the first direction <NUM> and facing the second upper surface portion <NUM>. The side surface <NUM> has a side surface dimension d in the first direction <NUM>. The side surface dimension d is larger than the first height h. In other words, the light-transmissive encapsulant <NUM> has a height that is more than that of the adhesive component <NUM>. This results in the light-transmissive encapsulant <NUM> having a side surface <NUM> that faces the adhesive component <NUM>.

In the lighting devices <NUM> of <FIG>, the elongated carrier <NUM> has an F-profile. The F-profile has a first profile part <NUM>, a second profile part <NUM>, and a third profile part <NUM>. The first profile part <NUM> and the second profile part <NUM> are oriented parallel to each other and perpendicular to the third profile part <NUM>. The first profile part <NUM> and the second profile part <NUM> are separated from each other by a non-zero separation distance.

In line with the terminology commonly used for structural beam profiles, each of the first profile part <NUM> and the second profile part <NUM> can be referred to as a flange, the third profile part <NUM> can be referred to as a web, and the space enclosed by the first profile part <NUM>, the second profile part <NUM>, and the third profile part <NUM> can be referred to as a channel.

The first upper surface portion <NUM> is located between the first profile part <NUM> and the second profile part <NUM>. In other words, in the lighting device <NUM> of <FIG>, the light-emitting diodes <NUM> are arranged in the channel between the flanges of the F-profile.

In the lighting device <NUM> of <FIG>, a cover <NUM> is provided over the first upper surface portion <NUM>. The cover <NUM> closes the separation distance between the first profile part <NUM> and the second profile part <NUM>. The cover <NUM> is shown as a separate component, but it may alternatively be an integral part of the profile of the elongated carrier. In the latter case, the elongated carrier would essentially have a P-profile. In the context of the present invention, a P-profile is considered an F-profile with a closed channel.

The lighting devices <NUM> shown in <FIG> are similar to those shown in <FIG>, respectively, but now the attachment component <NUM> has a first attachment component part <NUM> with a first adhesive surface portion <NUM> facing the first direction <NUM>, and a second attachment component part <NUM> with a second adhesive surface portion <NUM> facing the second direction <NUM>.

In the lighting device <NUM> of <FIG>, the second attachment component part <NUM> is provided on the side surface <NUM> of the light-transmissive encapsulant <NUM>.

In the lighting devices <NUM> of <FIG>, the second attachment component part <NUM> is provided on the first profile part <NUM> of the F-profile.

In the lighting devices <NUM> shown in <FIG>, the elongated carrier <NUM> has an upper surface <NUM> on which a plurality of light-emitting diodes <NUM> is arranged on a first upper surface portion <NUM>. The upper surface portion <NUM> substantially coincides with the upper surface <NUM>.

In the lighting devices <NUM> shown in <FIG>, the light-emitting diodes <NUM> are encapsulated with a light-transmissive encapsulant <NUM>.

In the lighting device <NUM> of <FIG>, the attachment component <NUM> is provided on a side surface of the light-transmissive encapsulant <NUM>. This side surface faces the second direction <NUM>.

In the lighting devices <NUM> of <FIG>, the elongated carrier <NUM> has a U-profile. The U-profile has a first profile part <NUM>, a second profile part <NUM>, and a third profile part <NUM>. The first profile part <NUM> and the second profile part <NUM> are oriented parallel to each other and perpendicular to the third profile part <NUM>. The first profile part <NUM> and the second profile part <NUM> are separated from each other by a non-zero separation distance. The first upper surface portion <NUM> is located between the first profile part <NUM> and the second profile part <NUM>.

In the lighting devices <NUM> of <FIG>, the attachment component <NUM> is provided on the first profile part <NUM> of the U-profile.

In the lighting device <NUM> of <FIG>, a cover <NUM> is provided over the first upper surface portion <NUM>. The cover <NUM> closes the separation distance between the first profile part <NUM> and the second profile part <NUM>. The cover <NUM> is shown as a separate component, but it may alternatively be an integral part of the profile of the elongated carrier. In the latter case, the elongated carrier would essentially be a rectangular tubing.

In the lighting devices <NUM> of <FIG>, the elongated carrier <NUM> has an upper surface <NUM>. The light-emitting diodes <NUM> are arranged on a first upper surface portion <NUM> of the upper surface <NUM>, and the attachment component <NUM> is arranged on a second upper surface portion <NUM> of the upper surface <NUM>, wherein the first upper surface portion <NUM> is located next to the second upper surface portion <NUM> in the direction of elongation <NUM> of the elongated carrier <NUM>. It is noted that, for the sake of clarity, the reference numerals <NUM>, <NUM> and <NUM> are not included in <FIG>. The features that these reference numerals refer to are analogous to the features with the same reference numerals as shown in the other figures.

The lighting device <NUM> shown in <FIG> is similar to the lighting device <NUM> shown in <FIG>. From the perspective of manufacturability, the lighting device <NUM> of <FIG> will be easiest to manufacture. It also has a layout that easily allows the elongated carrier <NUM> to be flexible.

The lighting device <NUM> shown in <FIG> has a configuration wherein the normal of the first surface part <NUM> is not parallel to the normal of the second surface part <NUM>. In other words, it has a configuration wherein the first surface part <NUM> is inclined with respect to the second surface part <NUM>. In the lighting device <NUM> shown in <FIG>, the elongated carrier <NUM> is rigid. Alternatively, the elongated carrier may be such that it can be deformed from a planar configuration into the configuration shown in <FIG>.

In the lighting devices <NUM> shown in <FIG>, the elongated carrier <NUM> has an L-profile, a T-profile, an F-profile and a P-profile, respectively. Such profiles result in an increased mechanical rigidity, with the P-profile providing the highest mechanical rigidity.

The lighting devices <NUM> of <FIG> all have a profile part that is oriented perpendicular to the first surface part <NUM> on which the light-emitting diodes <NUM> are arranged. These profile parts may be arranged to provide an optical effect chosen from the group consisting of refraction, diffraction, reflection, diffusion and conversion. The more profile parts, the more freedom to provide a variety of optical effects.

<FIG> shows a perspective view of a panel <NUM>, that may be used as a tabletop or a shelf. In the context of the present invention, tabletops and shelves and any other applications of a panel are considered examples of constructional elements.

The panel <NUM> has an upper surface and a lower surface. In the configuration shown <FIG>, the lower surface of the panel <NUM> represents a mounting surface for the lighting device <NUM>, which is similar to the lighting devices <NUM> shown in <FIG> and <FIG>. The lighting device <NUM> can be attached to the lower surface of the panel <NUM> via the attachment component <NUM>. For an observer that looks at the panel <NUM> from a side that is opposite to the side where the lighting device <NUM> is attached, the lighting device <NUM> is not in plain sight, but it is still capable of providing the same illumination output as a lighting device with an adhesive backing that would be attached to the upper surface of the panel <NUM>.

In an alternative configuration, the upper surface of the panel <NUM> represents a mounting surface to which the lighting device <NUM> may be attached via the attachment component <NUM>.

Each of <FIG> shows a side view of the panel <NUM> also shown in <FIG>. The upper and lower surfaces of the panel <NUM> are now indicated with reference numerals <NUM> and <NUM>, respectively. The panel <NUM> also has an edge surface <NUM>, which for the sake of clarity is only indicated in <FIG>.

In the configuration shown in <FIG>, lighting device <NUM>, which is similar to the lighting device <NUM> shown in <FIG>, is attached to the lower surface <NUM> of the panel <NUM> via the attachment component <NUM>. The side surface of the encapsulant <NUM> is used to align the lighting device <NUM> to the edge surface <NUM> of the panel <NUM>.

In the configuration shown in <FIG>, lighting device <NUM>, which is similar to the lighting device <NUM> shown in <FIG>, is attached to the edge surface <NUM> of the panel <NUM> via the first attachment component part <NUM>, and to the upper surface <NUM> via the second attachment component part <NUM>.

In the configuration shown in <FIG>, lighting device <NUM>, which is similar to the lighting device <NUM> shown in <FIG>, is attached to the edge surface <NUM> of the panel <NUM> via the attachment component <NUM>.

Claim 1:
A lighting device (<NUM>) arranged to be attached to a mounting surface of an object, the lighting device (<NUM>) comprising an LED strip (<NUM>), the LED strip (<NUM>) comprising:
- an elongated carrier (<NUM>) with an upper surface (<NUM>) having a first upper surface portion (<NUM>) and a second upper surface portion (<NUM>) located next to the first upper surface portion (<NUM>) in the direction of elongation (<NUM>) of the elongated carrier (<NUM>),
- a plurality of light-emitting diodes (<NUM>) arranged on the first upper surface portion (<NUM>), the plurality of light-emitting diodes (<NUM>) being encapsulated with a light-transmissive encapsulant (<NUM>), the light-transmissive encapsulant (<NUM>) being arranged to provide an optical effect chosen from the group consisting of refraction, diffraction, reflection, diffusion and conversion, and
- an attachment component (<NUM>) for attaching the lighting device (<NUM>) to the mounting surface,
wherein the attachment component (<NUM>) is provided on the second upper surface portion (<NUM>),
wherein the attachment component (<NUM>) comprises an adhesive surface (<NUM>) that faces in at least one of a first direction (<NUM>) and a second direction (<NUM>), the first direction (<NUM>) being parallel to the normal of the upper surface (<NUM>), and the second direction (<NUM>) being perpendicular to the normal of the upper surface (<NUM>) and to the direction of elongation (<NUM>) of the elongated carrier (<NUM>),
wherein the attachment component (<NUM>) has a first attachment component part (<NUM>) with a first adhesive surface portion (<NUM>) facing the first direction (<NUM>), the first adhesive surface portion (<NUM>) being located at a first height (h) from the upper surface (<NUM>) in the first direction (<NUM>), and
wherein the light-transmissive encapsulant (<NUM>) has a side surface (<NUM>) parallel to the first direction (<NUM>) and facing the second upper surface portion (<NUM>), the side surface (<NUM>) having a side surface dimension (d) in the first direction (<NUM>), and wherein the side surface dimension (d) is larger than the first height (h).